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Sample records for jacaranda mimosifolia tree

  1. Effects of arbuscular mycorrhizal inoculation and fertilization on mycorrhizal Statute of Jacaranda mimosifolia D.Don cultivated in nurseries.

    PubMed

    Zaouchi, Yousr; Bahri, Nada Ben; Rezgui, S; Bettaieb, Taoufik

    2013-10-01

    The effects of fertilization and the nature of the inoculum as well as the variation of the dose intake of the latter on the level of Jacaranda mimosifolia D.Don mycorhization were tested. Young plants were treated with two inoculums presenting different origins, compositions and modes of application: one is a commercial product containing Glomus irregulare, and the other is a composite indigenous inoculum resulting from trapping five species of genus Glomus and also from multiplication on mycotrophic plants: leek (Allium porrum L.) and vetch (Vicia sativa L.). For each inoculum, two doses were tested and for each dose of inoculum, four levels of fertilization based on a complete commercial fertilizer (Osmocote) were tested: 0 g/plant, 2 g/plant, 4 g/plant, and 6g/plant. Three repetitions were performed for each combination treatment of inoculum/fertilizer. One-year-old young Jacaranda plants, being about 40 cm high, were cultured under greenhouse in 10/12 cm caliber pots. After six months, all the inoculated plants were mycorrhized. According to endomycorrhizal structures found on their roots, plants receiving doses of composite indigenous inoculum reached a more advanced stage of mycorrhization than those treated with the commercial inoculum. The existence of an interaction effect between the inoculum dose and the level of fertilization on Jacaranda mycorhization rate was excluded. These two parameters of variation were studied as simple effects. The increase in commercial inoculum dose had a significant positive influence on the level of Jacaranda plants mycorrhization (P=0.05). The rate of mycorrhization jumped from 12.69% to 21.92%. Nonetheless, for plants receiving increasing doses of composite indigenous inoculum, the level of mycorrhization has varied randomly. In both instances of inoculum treatments, increasing the dose of fertilizer significantly inhibited endomycorrhizal colonization of Jacaranda roots (P=0.01). Thus, the rate of root colonization decreased from 47.43% to 2.41% for plants receiving the composite indigenous inoculums. It decreased from 32.35% to 3.95% for those treated with the commercial inoculum. Mycorrhization had a positive effect on root dry biomass of Jacaranda, as in the case of unfertilize ave the highest rates of colonization. PMID:24246891

  2. "KEEPING JACARANDA TREES HEALTHY" Prepared by: Vuledzani Muthelo (MSc student working on project entitled: "Structure of

    E-print Network

    "KEEPING JACARANDA TREES HEALTHY" Prepared by: Vuledzani Muthelo (MSc student working on project stad" (City of Jacarandas) due to the thousands of Jacaranda trees that are planted next to streets to the death of the trees. The fungus causing disease on the Jacaranda trees is suspected to belong to one

  3. Antioxidant and Cytotoxic Activity of Hydroethanolic Extract from Jacaranda decurrens Leaves

    PubMed Central

    Casagrande, Junior Cesar; Macorini, Luis Fernando Benitez; Antunes, Katia Avila; dos Santos, Uilson Pereira; Campos, Jaqueline Ferreira; Dias-Júnior, Nelson Miguel; Sangalli, Andréia; Lima Cardoso, Claudia Andrea; do Carmo Vieira, Maria; Rabelo, Luiza Antas; Paredes-Gamero, Edgar Julian; dos Santos, Edson Lucas; de Picoli Souza, Kely

    2014-01-01

    Background and Purpose Leaves of Jacaranda decurrens are used in traditional Brazilian medicine to treat metabolic diseases related to increased reactive oxygen species. The present study evaluated the antioxidant and cytotoxic potential of hydroethanolic extract from the leaves of Jacaranda decurrens subsp. symmetrifoliolata. Experimental Approach Phenolic compounds, flavonoids and saponins were evaluated in an ethanol?water (80?20, v/v) extract from the leaves of Jacaranda decurrens subsp. symmetrifoliolata (E-Jds). The antioxidant activity of E-Jds was investigated by assessing the following: 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity; protection against 2,2?-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced hemolysis of erythrocytes; in vitro and in vivo malondialdehyde dosage; and the ability to activate antioxidant enzymes. K562 leukemia cells were used for the cytotoxic evaluation of E-Jds and for the assessment of the cell death profile through flow cytometry. Key Results Phenolic and flavonoid compounds were quantified as 14.38% and 2.15%, respectively, of E-Jds. These phenolic and flavonoid compounds proved to be able to scavenge DPPH free radicals with an IC50 of 9.3±3.3 µg/mL, to protect up to 50% of erythrocytes against AAPH-induced hemolysis and to reduce in vitro and in vivo malondialdehyde levels up to 84% and 22%, respectively. E-Jds also increased glutathione peroxidase enzyme activity, with a concomitant decrease in superoxide dismutase and catalase activity, and exhibited dose-dependent cytotoxic activity on K562 erythroleukemia cells with cell death occurring via both late apoptosis and necrosis. Conclusions E-Jds exhibits in vitro and in vivo antioxidant potential, which may be the mechanism mediating the metabolic activities reported in folk medicine. Furthermore, the cytotoxic activity identified in this study contributes with the knowledge of antiproliferative activities that have been described in the literature for the genus Jacaranda. PMID:25402205

  4. Pollination Biology of Jacaranda oxyphylla with an Emphasis on Staminode Function

    PubMed Central

    Guimarães, Elza; di Stasi, Luiz Claudio; Maimoni-Rodella, Rita de Cassia Sindrônia

    2008-01-01

    Background and Aims Bignoniaceae is a Neotropical family with >100 genera, only two of which, Jacaranda and Digomphia, have a developed staminode. Jacaranda oxyphylla, whose flowers possess a conspicuous glandular staminode, is a zoophilous cerrado species. Here, the composition of the secretion of the glandular trichome and the influence of the staminode on the pollination biology and reproductive success of J. oxyphylla were studied. Methods The floral morphology, pollen viability, stigma receptivity, nectar volume and nectar concentration were studied. Compatibility system experiments were performed and floral visitors were observed and identified. Experiments comparing the effect of staminode presence and absence on pollen removal and pollen deposition efficiency were conducted in open-pollinated flowers. Histochemistry, thin-layer chromatography (TLC) and gas chromatography coupled to flame ionization detection (GC–FID) analyses were performed to determine the main chemical components of the staminode's glandular trichome secretion. Key Results Flower anthesis lasted 2 d and, despite the low frequency of flower visitation, pollination seemed to be effected mainly by medium-sized Eulaema nigrita and Bombus morio bees, by the small bee Exomalopsis fulvofasciata and occasionally by hummingbirds. Small bees belonging to the genera Ceratina, Augochlora and Trigona were frequent visitors, collecting pollen. Jacaranda oxyphylla is predominantly allogamous. Staminode removal resulted in fewer pollen grains deposited on stigmas but did not affect total pollen removal. The secretion of capitate glandular trichome occurs continually; the main chemical compounds detected histochemically were phenolic and terpenoid (essential oils and resins). Monoterpene cineole, pentacyclic triterpenes and steroids were identified by TLC and GC–FID. Conclusions The staminode of J. oxyphyllla is multifunctional and its importance for female reproductive success was attributed mainly to the secretion produced by capitate glandular trichomes. This secretion is involved in complex chemical interactions with pollinating bees, including the solitary bees Euglossini. These bees are common pollinators of various species of Jacaranda. PMID:18765441

  5. Histological features, starch accumulation and sprouting in the early root development of Jacaranda ulei (Bignoniaceae).

    PubMed

    Silva, Paulo R D da; Stefenon, Valdir M

    2014-03-01

    The plant species occurring in the savanna region of the Cerrado biome in Brazil present typical morphological and physiological adaptations to a dry climate with seasonal occurrence of wildfires. In this study, the histological features of the root system, the main sites of synthesis and storage of starch and the initial phases of the bud development were characterized in Jacaranda ulei. The anatomical features observed in the root system of J. ulei are related to the needs of the species to survive in the Cerrado. The histochemical analyses demonstrated high synthesis of glucose and glycoprotein after the third day of in vitro culture, in the proximal cells of the cortical parenchyma of the exoderm. Meristematic primordia were observed in the ninth day and the beginning of the meristem formation was observed after 21 days of in vitro culture. Jacaranda ulei displays morphological, anatomical and storage features typical from resprouter species. However, it may be vulnerable to unsustainable exploitation. Considering the importance of this species for local people, more studies regarding its therapeutic properties should be performed, including the planning of appropriate programs for the species management and the production of selected clones through in vitro micropropagation. PMID:24676167

  6. Toward a predictive model for water and carbon fluxes of non-native trees in urban habitats

    NASA Astrophysics Data System (ADS)

    McCarthy, H. R.; Jenerette, G. D.; Pataki, D. E.

    2008-12-01

    There is considerable interest in estimating uptake of water and carbon by urban trees, in order to assess some of the major costs and benefits associated with maintaining or expanding urban tree cover. However, making large-scale estimates of water and carbon fluxes is challenging in urban ecosystems, where community composition and environmental conditions are highly altered and experimental data is sparse. This is particularly true in regions such as southern California, where few trees are native, yet many species can flourish given supplemental irrigation. In such scenarios one practical way to scale water and carbon fluxes may be to identify reliable traits which can be used to predict gas exchange when trees are transplanted to a new environment. To test this approach, leaf level gas exchange measurements were conducted on eight common urban tree species within the Los Angeles basin. The objective was to determine how well gas exchange parameters, including maximum photosynthesis and stomatal conductance, sensitivity of stomatal conductance to vapor pressure deficit (VPD), and water use efficiency (WUE), can be predicted based on the native habitat and climate (temperature and precipitation) of each study species. All of the species studied naturally occur in humid tropical or subtropical climate zones where precipitation varies widely from ~400 - 3000 mm per year. We found Jacaranda (Jacaranda chelonia) and honey locust (Gleditsia triacanthos) to have the highest photosynthesis and reference (at VPD=1 kPa) conductance, and to be most sensitive to VPD. WUE was found to be greatest in Indian laurel fig (Ficus microcarpa), rose gum (Eucalyptus grandis) and Queensland lacebark (Brachychiton discolor). The relative ordering of maximum photosynthesis and conductance across species was not entirely predictable based on our current knowledge of the native habitats of each species: several other species had similar native climates to Jacaranda and honey locust, yet had lower photosynthesis and conductance. However, WUE generally followed the expected trends, with species predicted to have low conductance showing higher WUE. This implies that WUE is strongly genetically controlled and may be predictable with knowledge of imported species' native habitat. Other traits, such as leaf nitrogen and isotopes, are also being investigated as proxies for detailed gas exchange measurements in this ecosystem. Further refinement of predictive factors will facilitate conceptual and quantitative models that can be used for robust scaling of water and carbon fluxes from trees to urban regions.

  7. Tree Location One, Two, Tree!

    E-print Network

    Ashline, George

    Tree Location One, Two, Tree! Let's Learn about the Linden! A tree activity for little Seedlings colors on a piece of paper. What are the parts of the tree? 1.) See if you can name all the different parts of the tree. 2.) Write down the parts on a piece of paper. What do you see in, on, or around

  8. Flower Face Face Face Face Flower Tree Tree Tree Tree

    E-print Network

    Chen, Tsuhan

    Flower Flower Flower Flower Flower Face Face Face Face Flower Flower Tree Tree Tree Tree Flower Flower Flower Flower Sky Sky Sky Sky Flower Grass Grass Grass Grass Flower Flower Flower #12;Sign Sign Road Road Chair Face Face Face Face Chair #12;Chair Chair Chair Flower Flower Flower Flower Grass Chair

  9. TREE TRAILS Tree Scavenger Hunt

    E-print Network

    _______________________ Birdhouse _______________________ Food packaging _______________________ Chocolate) Food packaging - pulp Chocolate - nut (from cacao tree) Charcoal - wood Expert Items: Find it = 3

  10. Tree Amigos.

    ERIC Educational Resources Information Center

    Center for Environmental Study, Grand Rapids, MI.

    Tree Amigos is a special cross-cultural program that uses trees as a common bond to bring the people of the Americas together in unique partnerships to preserve and protect the shared global environment. It is a tangible program that embodies the philosophy that individuals, acting together, can make a difference. This resource book contains…

  11. Talking Trees

    ERIC Educational Resources Information Center

    Tolman, Marvin

    2005-01-01

    Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. Through these activities, students will learn to identify the major characteristics of trees and discover how the pace--a nonstandard measuring unit--can be used to estimate not only distances but also the…

  12. Audubon Tree Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Trees," a leaders' guide, and a large tree chart with 37 colored pictures. The student reader reviews several aspects of trees: a definition of a tree; where and how trees grow; flowers, pollination and seed production; how trees make their food; how to recognize trees; seasonal changes;…

  13. Assessing the extent of "conflict of use" in multipurpose tropical forest trees: a regional view.

    PubMed

    Herrero-Jáuregui, Cristina; Guariguata, Manuel R; Cárdenas, Dairon; Vilanova, Emilio; Robles, Marco; Licona, Juan Carlos; Nalvarte, Walter

    2013-11-30

    In the context of multiple forest management, multipurpose tree species which provide both timber and non-timber forest products (NTFP), present particular challenges as the potential of conflicting use for either product may be high. One key aspect is that the magnitude of conflict of use can be location specific, thus adding complexity to policy development. This paper focuses on the extent to which the potential for conflict of use in multipurpose tree species varies across the Amazonian lowland forests shared by Peru, Bolivia, Colombia, Ecuador and Venezuela, emphasizing the economic dimension of conflict. Based on a review of the current normative and regulatory aspects of timber and NTFP extraction in the five countries, the paper also briefly discusses the opportunities and constraints for harmonization of timber and NTFP management of multipurpose species across the region. It was found that about half of the 336 timber species reviewed across the five countries also have non-timber uses. Eleven timber species are multipurpose in all five countries: Calophyllum brasiliense, Cedrela odorata, Ceiba pentandra, Clarisia racemosa, Ficus insipida, Jacaranda copaia, Schefflera morototoni, Simarouba amara and Terminalia amazonia. Seven other multipurpose species occurred only in either Venezuela (Tabebuia impetiginosa, Spondias mombin, Pentaclethra macroloba, Copaifera officinalis, Chlorophora tinctoria, Carapa guianensis) or Ecuador (Tabebuia chrysantha). Four multipurpose tree species presented the highest potential of conflict of use across the region: Dipteryx odorata, Tabebuia serratifolia, Hymenaea courbaril and Myroxylon balsamum yet these were not evenly distributed across all five countries. None of the five studied countries have specific legislation to promote sustainable use of any of the multipurpose species reported here and thus mitigate potential conflict of use; nor documented management options for integration or else segregation of both their timber and NTFP values. PMID:24061084

  14. Minimizing Tree Automata for Unranked Trees

    E-print Network

    Martens, Wim

    Minimizing Tree Automata for Unranked Trees Wim Martens Joachim Niehren Minimizing Tree Automata for Unranked Trees ­ p.1/20 #12;What and Why? To study the minimization problem for deterministic automata over unranked trees. Bottom-up deterministic: theoretical interest. E.g. do results from deterministic automata

  15. Technical Tree Climbing.

    ERIC Educational Resources Information Center

    Jenkins, Peter

    Tree climbing offers a safe, inexpensive adventure sport that can be performed almost anywhere. Using standard procedures practiced in tree surgery or rock climbing, almost any tree can be climbed. Tree climbing provides challenge and adventure as well as a vigorous upper-body workout. Tree Climbers International classifies trees using a system…

  16. Meet the Ginkgo Tree Ginkgo Tree

    E-print Network

    Ashline, George

    Meet the Ginkgo Tree Ginkgo Tree Seedling Activity Tree location Try this... The Ginkgo tree has a unique leaf shape. To explore the shape of the Ginkgo leaf let's make a mini fan! · Look all around take the fan with you to keep cool all day long. You can also take your fan-shaped Ginkgo leaf

  17. Essential Kurepa Trees Versus Essential Jech Kunen Trees1

    E-print Network

    Jin, Renling

    Essential Kurepa Trees Versus Essential Jech Kunen Trees1 Renling Jin2 & Saharon Shelah3 Abstract By an !1 tree we mean a tree of cardinality !1 and height !1. An !1 tree is called a Kurepa tree if all its levels are countable and it has more than !1 branches. An !1 tree is called a Jech Kunen tree if it has

  18. A tree-to-tree model for statistical machine translation

    E-print Network

    Cowan, Brooke A. (Brooke Alissa), 1972-

    2008-01-01

    In this thesis, we take a statistical tree-to-tree approach to solving the problem of machine translation (MT). In a statistical tree-to-tree approach, first the source-language input is parsed into a syntactic tree ...

  19. TREE TRAILS Tree measurement is fundamental to the practice of forestry. Foresters count trees and measure trees.

    E-print Network

    1 TREE TRAILS Tree measurement is fundamental to the practice of forestry. Foresters count trees and measure trees. With just a few basic measurements, we can assign values to trees and compare them to each other. Tree Trails Tree Measurement Goal: Students will measure trees and explain how measurement

  20. Limit Laws for Functions of Fringe trees for Binary Search Trees and Random Recursive Trees

    E-print Network

    Janson, Svante

    Limit Laws for Functions of Fringe trees for Binary Search Trees and Random Recursive Trees Cecilia for sums of functions of subtrees of (random) binary search trees and random recursive trees. The proofs that the number of fringe trees of size k = kn in the binary search tree or in the random recursive tree (of total

  1. The Needs of Trees

    ERIC Educational Resources Information Center

    Boyd, Amy E.; Cooper, Jim

    2004-01-01

    Tree rings can be used not only to look at plant growth, but also to make connections between plant growth and resource availability. In this lesson, students in 2nd-4th grades use role-play to become familiar with basic requirements of trees and how availability of those resources is related to tree ring sizes and tree growth. These concepts can…

  2. Categorizing Ideas about Trees: A Tree of Trees

    PubMed Central

    Fisler, Marie; Lecointre, Guillaume

    2013-01-01

    The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a “tree of trees.” Then, we categorize schools of tree-representations. Classical schools like “cladists” and “pheneticists” are recovered but others are not: “gradists” are separated into two blocks, one of them being called here “grade theoreticians.” We propose new interesting categories like the “buffonian school,” the “metaphoricians,” and those using “strictly genealogical classifications.” We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization. PMID:23950877

  3. Big Tree Measurement and Scoring: Virginia Big Tree Program

    E-print Network

    Virginia Tech

    accurate for straight trees on flat ground. Tree Height 1 big tree point is awarded for each foot of tree://www.americanforests.org/bigtrees/ champion-tree-measuring-guidelines #12;Trunk Circumference A. B. C. D. A. For typical trees on flat ground Spread ¼ big tree point is awarded for each foot of crown spread #12;

  4. COMPONENT User's Guide Random trees

    E-print Network

    Page, Roderic

    COMPONENT User's Guide Chapter 6 Random trees COMPONENT can generate a variety of trees at "random," and for small numbers of leaves it can generate all possible trees. These trees have several uses: n as user trees for phylogeny programs that lack the facility to examine all trees or sets of random trees (e

  5. Long-term impacts of selective logging on two Amazonian tree species with contrasting ecological and reproductive characteristics: inferences from Eco-gene model simulations.

    PubMed

    Vinson, C C; Kanashiro, M; Sebbenn, A M; Williams, T C R; Harris, S A; Boshier, D H

    2015-08-01

    The impact of logging and subsequent recovery after logging is predicted to vary depending on specific life history traits of the logged species. The Eco-gene simulation model was used to evaluate the long-term impacts of selective logging over 300 years on two contrasting Brazilian Amazon tree species, Dipteryx odorata and Jacaranda copaia. D. odorata (Leguminosae), a slow growing climax tree, occurs at very low densities, whereas J. copaia (Bignoniaceae) is a fast growing pioneer tree that occurs at high densities. Microsatellite multilocus genotypes of the pre-logging populations were used as data inputs for the Eco-gene model and post-logging genetic data was used to verify the output from the simulations. Overall, under current Brazilian forest management regulations, there were neither short nor long-term impacts on J. copaia. By contrast, D. odorata cannot be sustainably logged under current regulations, a sustainable scenario was achieved by increasing the minimum cutting diameter at breast height from 50 to 100?cm over 30-year logging cycles. Genetic parameters were only slightly affected by selective logging, with reductions in the numbers of alleles and single genotypes. In the short term, the loss of alleles seen in J. copaia simulations was the same as in real data, whereas fewer alleles were lost in D. odorata simulations than in the field. The different impacts and periods of recovery for each species support the idea that ecological and genetic information are essential at species, ecological guild or reproductive group levels to help derive sustainable management scenarios for tropical forests. PMID:24424164

  6. From Gene Trees to Species Trees II: Species Tree Inference by Minimizing Deep

    E-print Network

    Zhang, Louxin

    From Gene Trees to Species Trees II: Species Tree Inference by Minimizing Deep Coalescence Events Louxin Zhang Abstract--When gene copies are sampled from various species, the resulting gene tree might disagree with the containing species tree. The primary causes of gene tree and species tree discord include

  7. On Gracefully Labeling Trees

    E-print Network

    Dhananjay P. Mehendale

    2013-10-25

    A method to obtain all possible graceful spanning trees in a complete graph is proposed. An algorithm to generate all the labeled spanning trees in a complete graph is developed and modified to generate all graceful spanning trees. The count of all possible graceful graphs in a complete graph is obtained. An upper bound on the count of gracefully labeled trees in a complete graph is obtained. We settle Graceful Tree Conjecture in the affirmative in two ways: 1) We show that all trees can be gracefully labeled by assigning the lowest label 1 to the so called special vertices of trees, i.e. prependant vertices or pendant vertices adjacent to prependant vertices. 2) We establish the existence of graceful labeling for all trees by associating distinct lattice paths with trees and by showing the existence of a lattice path for a tree of each isomorphism type by showing how to construct a lattice path recursively by starting from the lattice path for its pendant vertex deleted subtree, which is assumed to exists by induction, and carrying out appropriate modification of this lattice path. 3) We propose a crisp algorithm to gracefully label tree of every isomorphism type with the help of novel representation for any tree in terms of juxtaposition of paths. Lastly, we discuss an algorithm to find arbitrarily degree constrained graceful spanning tree and propose some problems for further investigation.

  8. Let's Explore the Ginkgo Tree! Ginkgo tree

    E-print Network

    Ashline, George

    of the Ginkgo tree in fossils dating back to time of the dinosaurs. Today you can create your own leaf fossil for the correct measurements of water and plaster. Let the plaster sit for the appropriate time. · Gently place take the fossil home and tell the story of how the Ginkgo tree was discovered. Do you want to lean more

  9. Evolution of tree nutrition.

    PubMed

    Raven, John A; Andrews, Mitchell

    2010-09-01

    Using a broad definition of trees, the evolutionary origins of trees in a nutritional context is considered using data from the fossil record and molecular phylogeny. Trees are first known from the Late Devonian about 380 million years ago, originated polyphyletically at the pteridophyte grade of organization; the earliest gymnosperms were trees, and trees are polyphyletic in the angiosperms. Nutrient transporters, assimilatory pathways, homoiohydry (cuticle, intercellular gas spaces, stomata, endohydric water transport systems including xylem and phloem-like tissue) and arbuscular mycorrhizas preceded the origin of trees. Nutritional innovations that began uniquely in trees were the seed habit and, certainly (but not necessarily uniquely) in trees, ectomycorrhizas, cyanobacterial, actinorhizal and rhizobial (Parasponia, some legumes) diazotrophic symbioses and cluster roots. PMID:20581011

  10. Graph homomorphisms between trees

    E-print Network

    Csikvari, Peter

    In this paper we study several problems concerning the number of homomorphisms of trees. We begin with an algorithm for the number of homomorphisms from a tree to any graph. By using this algorithm and some transformations ...

  11. Minimal locked trees

    E-print Network

    Ballinger, Brad

    Locked tree linkages have been known to exist in the plane since 1998, but it is still open whether they have a polynomial-time characterization. This paper examines the properties needed for planar trees to lock, with a ...

  12. 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.

  13. Simplifying Decision Trees

    E-print Network

    Quinlan, J.R.

    1986-12-01

    Many systems have been developed for constructing decision trees from collections of examples. Although the decision trees generated by these methods are accurate and efficient, they often suffer the disadvantage of ...

  14. Tea Tree Oil

    MedlinePLUS

    ... Top Key References Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (tea tree) oil: a review of ... 2006;19(1):50–62. Carson CF, Riley TV. Safety, efficacy and provenance of tea tree (Melaleuca ...

  15. Chem-Is-Tree.

    ERIC Educational Resources Information Center

    Barry, Dana M.

    1997-01-01

    Provides details on the chemical composition of trees including a definition of wood. Also includes an activity on anthocyanins as well as a discussion of the resistance of wood to solvents and chemicals. Lists interesting products from trees. (DDR)

  16. Grizzly Giant Tree

    USGS Multimedia Gallery

    This giant sequoia is named the Grizzly Giant, the oldest sequoia tree in the Mariposa Grove of Big Trees, located within Yosemite National Park. It is believed to be between 1,900 and 2,400 years old. ...

  17. Binary Search Trees Page 1 Binary Search Trees

    E-print Network

    Allan, Vicki H.

    Binary Search Trees Page 1 Chapter 4 Trees Binary Search Trees · Definition o All keys are distinct subtree is greater than the root. o Left and right subtrees are binary search trees. · Figure 1 is an example: Figure 1 Binary Search Tree · Where would you add X, B, and E? · At seats, build tree from

  18. Discordance of species trees with their most likely gene trees

    E-print Network

    Degnan, James

    Discordance of species trees with their most likely gene trees James H. Degnan & Noah A. Rosenberg sort during speciation, gene trees may differ in topology from each other and from species trees gene tree discordance is so common that the most likely gene tree topology to evolve along the branches

  19. Avery Andrews' Trees Preprocessor

    E-print Network

    Pratt, Vaughan

    Avery Andrews' Trees Preprocessor Consider the tree shown in (1): (1) S NP that book S/NP NP I VP/NP V want VP/NP to VP/NP V ask NP Mary VP/NP to VP/NP V send NP Tom NP/NP e Making trees like this in T E X or L A T E X can be a cause for dread. But it can become quite simple and fun with the trees

  20. Decision-Tree Program

    NASA Technical Reports Server (NTRS)

    Buntine, Wray

    1994-01-01

    IND computer program introduces Bayesian and Markov/maximum-likelihood (MML) methods and more-sophisticated methods of searching in growing trees. Produces more-accurate class-probability estimates important in applications like diagnosis. Provides range of features and styles with convenience for casual user, fine-tuning for advanced user or for those interested in research. Consists of four basic kinds of routines: data-manipulation, tree-generation, tree-testing, and tree-display. Written in C language.

  1. Basswood Tree Seedling activity

    E-print Network

    Ashline, George

    board or sturdy white paper · Glue · Markers · Ruler · Tell Me, Tree by Gail Gibbons Procedure: · Read the book Tell Me, Tree. · Collect a leaf that has no holes. · Cut a piece of poster board that is about 6. · On the first line, write the name of the tree. · On the second line, write the characteristics of the tree

  2. Pecan tree biomass estimates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Allometric equations were developed for orchard-grown pecan [Carya illinoinensis (Wangenh.) C. Koch] trees. Trees, ranging in size from 22 to 33 cm in trunk diameter 1.4 m above the ground, were destructively harvested from two sites. The entire above-ground portion of the trees was harvested and...

  3. The Wish Tree Project

    ERIC Educational Resources Information Center

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  4. Minnesota's Forest Trees. Revised.

    ERIC Educational Resources Information Center

    Miles, William R.; Fuller, Bruce L.

    This bulletin describes 46 of the more common trees found in Minnesota's forests and windbreaks. The bulletin contains two tree keys, a summer key and a winter key, to help the reader identify these trees. Besides the two keys, the bulletin includes an introduction, instructions for key use, illustrations of leaf characteristics and twig…

  5. Structural Equation Model Trees

    ERIC Educational Resources Information Center

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2013-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree

  6. Winter Birch Trees

    ERIC Educational Resources Information Center

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  7. Representing Trees with Constraints 

    E-print Network

    Curry, Benjamin; Wiggins, Geraint; Hayes, Gillian

    This paper presents a method for representing trees using constraint logic programming over finite domains. We describe a class of trees that is of particular interest to us and how we can represent the set of trees belonging to that class using...

  8. Growth of a Pine Tree

    ERIC Educational Resources Information Center

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  9. Distributed Contour Trees

    SciTech Connect

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di#11;erent problems that rely on contour trees can be solved in parallel with minimal communication.

  10. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Color-shifted complexes Weighted spanning tree enumerators of color-shifted complexes Ghodratollah Aalipour1,2 Art Duval1 1University Ghodratollah Aalipour, Art Duval Spanning tree enumerators of color-shifted complexes #12;Spanning trees

  11. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 Aalipour, Art Duval Spanning tree enumerators of complete colorful complexes #12;Spanning trees of graphs

  12. Discordance of Species Trees with Their Most Likely Gene Trees

    E-print Network

    Rosenberg, Noah

    Discordance of Species Trees with Their Most Likely Gene Trees James H. Degnan1 , Noah A. Rosenberg way in which lineages sort during speciation, gene trees may differ in topology from each other for which gene tree discordance is so common that the most likely gene tree topology to evolve along

  13. Condensation in nongeneric trees

    E-print Network

    Thordur Jonsson; Sigurdur Orn Stefansson

    2011-01-04

    We study nongeneric planar trees and prove the existence of a Gibbs measure on infinite trees obtained as a weak limit of the finite volume measures. It is shown that in the infinite volume limit there arises exactly one vertex of infinite degree and the rest of the tree is distributed like a subcritical Galton-Watson tree with mean offspring probability $mtrees in the thermodynamic limit and show it goes like $(1-m)N$ where $N$ is the size of the tree. These trees have infinite spectral dimension with probability one but the spectral dimension calculated from the ensemble average of the generating function for return probabilities is given by $2\\beta -2$ if the weight $w_n$ of a vertex of degree $n$ is asymptotic to $n^{-\\beta}$.

  14. Species integrity in trees.

    PubMed

    Ortiz-Barrientos, Daniel; Baack, Eric J

    2014-09-01

    From California sequoia, to Australian eucalyptus, to the outstanding diversity of Amazonian forests, trees are fundamental to many processes in ecology and evolution. Trees define the communities that they inhabit, are host to a multiplicity of other organisms and can determine the ecological dynamics of other plants and animals. Trees are also at the heart of major patterns of biodiversity such as the latitudinal gradient of species diversity and thus are important systems for studying the origin of new plant species. Although the role of trees in community assembly and ecological succession is partially understood, the origin of tree diversity remains largely opaque. For instance, the relative importance of differing habitats and phenologies as barriers to hybridization between closely related species is still largely uncharacterized in trees. Consequently, we know very little about the origin of trees species and their integrity. Similarly, studies on the interplay between speciation and tree community assembly are in their infancy and so are studies on how processes like forest maturation modifies the context in which reproductive isolation evolves. In this issue of Molecular Ecology, Lindtke et al. (2014) and Lagache et al. (2014) overcome some traditional difficulties in studying mating systems and sexual isolation in the iconic oaks and poplars, providing novel insights about the integrity of tree species and on how ecology leads to variation in selection on reproductive isolation over time and space. PMID:25155715

  15. Texas Shade Trees 

    E-print Network

    Unknown

    2011-09-05

    second among the states in the number of bearing peach trees, having 9,737,000 trees. A majority of these trees were growing in a few districts; 10 per cent were located in a single county, and more than 50 per cent in half ·a dozen counties of Northeast... Texas. Of the 417,770 farms reported in the state in 1910, only 108,959, or 25 per cent, reported any peach trees. A lack of knowledge of peach culture is believed to be responsible ior this uneven distribution of orchards. To meet this situation...

  16. COMPONENT User's Guide Working with trees

    E-print Network

    Page, Roderic

    COMPONENT User's Guide Chapter 2 Working with trees This chapter gives you information on basic tree operations. The topics covered include: n reading and writing files of trees n editing trees n displaying and printing trees n selecting subsets of trees n pruning trees n rooting trees n computing tree

  17. COMPONENT User's Guide Comparing trees

    E-print Network

    Page, Roderic

    COMPONENT User's Guide Chapter 5 Comparing trees This chapter describes the tree comparison measures available in COMPONENT, and the various ways you can compare trees using the program. Among the possible uses of tree comparison measures are: n comparing trees for the same taxa computed from different

  18. Apple Tree, NH Big Tree for May By Anne Krantz, NH Big Tree Team,

    E-print Network

    New Hampshire, University of

    Apple Tree, NH Big Tree for May By Anne Krantz, NH Big Tree Team, UNH Cooperative Extension The explosion of apple blossoms in May transforms the most gnarled old tree into a delicate cloud of beauty (1817-1862) in his essay "The Wild Apple Tree," described the blossoms perfectly: `The flowers

  19. Tree nut oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major tree nuts include almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts. Tree nut oils are appreciated in food applications because of their flavors and are generally more expensive than other gourmet oils. Research during the last de...

  20. CSI for Trees

    ERIC Educational Resources Information Center

    Rubino, Darrin L.; Hanson, Deborah

    2009-01-01

    The circles and patterns in a tree's stem tell a story, but that story can be a mystery. Interpreting the story of tree rings provides a way to heighten the natural curiosity of students and help them gain insight into the interaction of elements in the environment. It also represents a wonderful opportunity to incorporate the nature of science.…

  1. Tree Topology Estimation

    PubMed Central

    Estrada, Rolando; Tomasi, Carlo; Schmidler, Scott C.; Farsiu, Sina

    2015-01-01

    Tree-like structures are fundamental in nature, and it is often useful to reconstruct the topology of a tree—what connects to what—from a two-dimensional image of it. However, the projected branches often cross in the image: the tree projects to a planar graph, and the inverse problem of reconstructing the topology of the tree from that of the graph is ill-posed. We regularize this problem with a generative, parametric tree-growth model. Under this model, reconstruction is possible in linear time if one knows the direction of each edge in the graph—which edge endpoint is closer to the root of the tree—but becomes NP-hard if the directions are not known. For the latter case, we present a heuristic search algorithm to estimate the most likely topology of a rooted, three-dimensional tree from a single two-dimensional image. Experimental results on retinal vessel, plant root, and synthetic tree datasets show that our methodology is both accurate and efficient. PMID:26353004

  2. TRANSPLANTING SHADE TREES.

    ERIC Educational Resources Information Center

    Illinois Univ., Urbana. Coll. of Agriculture.

    THIS RESOURCE MATERIAL FOR USE IN HIGH SCHOOL VOCATIONAL AGRICULTURE AND ADULT FARMER CLASSES WAS DESIGNED BY SUBJECT MATTER SPECIALISTS, TEACHER EDUCATORS, SUPERVISORS, AND TEACHERS. THE OBJECTIVE IS TO HELP SOLVE PROBLEMS IN TRANSPLANTING SHADE TREES. THE MAJOR SECTION TITLES ARE STATED AS PROBLEMS -- (1) HOW SHOULD I PREPARE A TREE FOR MOVING,…

  3. Trees for Mother Earth.

    ERIC Educational Resources Information Center

    Greer, Sandy

    1993-01-01

    Describes Trees for Mother Earth, a program in which secondary students raise funds to buy fruit trees to plant during visits to the Navajo Reservation. Benefits include developing feelings of self-worth among participants, promoting cultural exchange and understanding, and encouraging self-sufficiency among the Navajo. (LP)

  4. Trees in Our Lives.

    ERIC Educational Resources Information Center

    NatureScope, 1986

    1986-01-01

    Provides: (1) background information on how trees have influenced human history and how trees affect people today; (2) four activities dealing with these topics; and (3) a ready-to-copy page related to paper and plastics. Activities include an objective, recommended age level(s), subject area(s), list of materials needed, and procedures. (JN)

  5. Trees Are Terrific!

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. Contents are organized into the following sections: (1) "What Makes a Tree a Tree?," including information…

  6. Lazy decision trees

    SciTech Connect

    Friedman, J.H.; Yun, Yeogirl; Kohavi, R.

    1996-12-31

    Lazy learning algorithms, exemplified by nearest-neighbor algorithms, do not induce a concise hypothesis from a given training set; the inductive process is delayed until a test instance is given. Algorithms for constructing decision trees, such as C4.5, ID3, and CART create a single {open_quotes}best{close_quotes} decision tree during the training phase, and this tree is then used to classify test instances. The tests at the nodes of the constructed tree are good on average, but there may be better tests for classifying a specific instance. We propose a lazy decision tree algorithm-LazyDT-that conceptually constructs the {open_quotes}best{close_quote} decision tree for each test instance. In practice, only a path needs to be constructed, and a caching scheme makes the algorithm fast. The algorithm is robust with respect to missing values without resorting to the complicated methods usually seen in induction of decision trees. Experiments on real and artificial problems are presented.

  7. 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.

  8. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Color-shifted complexes Weighted spanning tree enumerators of color-shifted complexes Ghodratollah Aalipour1,2 Art Duval1 1University in St. Louis October 20, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of color

  9. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 Mathematics Colloquium New Mexico State University October 20, 2011 Duval, Klivans, Martin Spanning trees

  10. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 of Kansas Discrete CATS seminar University of Kentucky March 30, 2011 Duval, Klivans, Martin Spanning trees

  11. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 of Mississippi March 2, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of complete colorful

  12. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 April 21, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of complete colorful complexes

  13. Spanning trees of graphs Spanning trees of simplicial complexes

    E-print Network

    Duval, Art

    Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 of Kansas Mathematics Seminar Reed College April 28, 2011 Duval, Klivans, Martin Spanning trees

  14. Global Tree Optimization: A Nongreedy Decision Tree Algorithm

    E-print Network

    Mitchell, John E.

    Global Tree Optimization: A Non­greedy Decision Tree Algorithm Kristin P. Bennett Email bennek­greedy approach for constructing globally optimal multivariate decision trees with fixed structure is pro­ posed­ rion at each decision node, typically one node at a time. In contrast, global tree optimization

  15. Evolutionary tree reconstruction

    NASA Technical Reports Server (NTRS)

    Cheeseman, Peter; Kanefsky, Bob

    1990-01-01

    It is described how Minimum Description Length (MDL) can be applied to the problem of DNA and protein evolutionary tree reconstruction. If there is a set of mutations that transform a common ancestor into a set of the known sequences, and this description is shorter than the information to encode the known sequences directly, then strong evidence for an evolutionary relationship has been found. A heuristic algorithm is described that searches for the simplest tree (smallest MDL) that finds close to optimal trees on the test data. Various ways of extending the MDL theory to more complex evolutionary relationships are discussed.

  16. 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.

  17. The gravity apple tree

    NASA Astrophysics Data System (ADS)

    Espinosa Aldama, Mariana

    2015-04-01

    The gravity apple tree is a genealogical tree of the gravitation theories developed during the past century. The graphic representation is full of information such as guides in heuristic principles, names of main proponents, dates and references for original articles (See under Supplementary Data for the graphic representation). This visual presentation and its particular classification allows a quick synthetic view for a plurality of theories, many of them well validated in the Solar System domain. Its diachronic structure organizes information in a shape of a tree following similarities through a formal concept analysis. It can be used for educational purposes or as a tool for philosophical discussion.

  18. The gene tree delusion.

    PubMed

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ?12bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are grossly misaligned, and numerous loci with >50% missing data for taxa that are misplaced in their gene trees. These problems were compounded by inadequate tree searches with nearest neighbor interchange branch swapping and inadvertent application of substitution models that did not account for among-site rate heterogeneity. Sixty-six gene trees imply unrealistic deep coalescences that exceed 100 million years (MY). Gene trees that were obtained with better justified models and search parameters show large increases in both likelihood scores and congruence. Coalescence analyses based on a curated set of 413 improved gene trees and a superior coalescence method (ASTRAL) support a Scandentia (treeshrews)+Glires (rabbits, rodents) clade, contradicting one of the three primary systematic conclusions of Song et al. (2012). Robust support for a Perissodactyla+Carnivora clade within Laurasiatheria is also lost, contradicting a second major conclusion of this study. Song et al.'s (2012) MP-EST species tree provided the basis for circular simulations that led these authors to conclude that the multispecies coalescent accounts for 77% of the gene tree conflicts in their dataset, but many internal branches of their MP-EST tree are stunted by an order of magnitude or more due to wholesale gene tree reconstruction errors. An independent assessment of branch lengths suggests the multispecies coalescent accounts for ?15% of the conflicts among Song et al.'s (2012) 447 gene trees. Unfortunately, Song et al.'s (2012) flawed phylogenomic dataset has been used as a model for additional simulation work that suggests the superiority of shortcut coalescence methods relative to concatenation. Investigator error was passed on to the subsequent simulation studies, which also incorporated further logical errors that should be avoided in future simulation studies. Illegitimate branch length switches in the simulation routines unfairly protected coalescence methods from their Achilles' heel, high gene tree reconstruction error at short internodes. These simulations therefore provide no

  19. Tree Disease Laboratory - 1 

    E-print Network

    Unknown

    2005-06-30

    Many homeowners need help caring for or removing damaged trees after a natural disaster. This publication explains what a certified arborist is and how to select one. It also cautions against burning debris downed by a storm....

  20. Tree-bank grammars

    SciTech Connect

    Charniak, E.

    1996-12-31

    By a {open_quotes}tree-bank grammar{close_quotes} we mean a context-free grammar created by reading the production rules directly from hand-parsed sentences in a tree bank. Common wisdom has it that such grammars do not perform well, though we know of no published data on the issue. The primary purpose of this paper is to show that the common wisdom is wrong. In particular, we present results on a tree-bank grammar based on the Penn Wall Street Journal tree bank. To the best of our knowledge, this grammar outperforms all other non-word-based statistical parsers/grammars on this corpus. That is, it outperforms parsers that consider the input as a string of tags and ignore the actual words of the corpus.

  1. Tea tree oil

    MedlinePLUS

    ... the skin (used topically) for infections such as acne, fungal infections of the nail (onychomycosis), lice, scabies, ... two months has no benefit. Mild to moderate acne. Applying a 5% tea tree oil gel appears ...

  2. Structural Equation Model Trees

    PubMed Central

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2015-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree structures that separate a data set recursively into subsets with significantly different parameter estimates in a SEM. SEM Trees provide means for finding covariates and covariate interactions that predict differences in structural parameters in observed as well as in latent space and facilitate theory-guided exploration of empirical data. We describe the methodology, discuss theoretical and practical implications, and demonstrate applications to a factor model and a linear growth curve model. PMID:22984789

  3. Tea tree oil

    MedlinePLUS

    ... infection as medications such as clotrimazole or terbinafine. Fungus infections of the nails (onychomycosis). Topical application of ... in tea tree oil may kill bacteria and fungus, and reduce allergic skin reactions.

  4. Leonardo's Tree Theory.

    ERIC Educational Resources Information Center

    Werner, Suzanne K.

    2003-01-01

    Describes a series of activities exploring Leonardo da Vinci's tree theory that are designed to strengthen 8th grade students' data collection and problem solving skills in physical science classes. (KHR)

  5. Tea tree oil.

    PubMed

    Larson, David; Jacob, Sharon E

    2012-01-01

    Tea tree oil is an increasingly popular ingredient in a variety of household and cosmetic products, including shampoos, massage oils, skin and nail creams, and laundry detergents. Known for its potential antiseptic properties, it has been shown to be active against a variety of bacteria, fungi, viruses, and mites. The oil is extracted from the leaves of the tea tree via steam distillation. This essential oil possesses a sharp camphoraceous odor followed by a menthol-like cooling sensation. Most commonly an ingredient in topical products, it is used at a concentration of 5% to 10%. Even at this concentration, it has been reported to induce contact sensitization and allergic contact dermatitis reactions. In 1999, tea tree oil was added to the North American Contact Dermatitis Group screening panel. The latest prevalence rates suggest that 1.4% of patients referred for patch testing had a positive reaction to tea tree oil. PMID:22653070

  6. Generalized constructive tree weights

    SciTech Connect

    Rivasseau, Vincent E-mail: adrian.tanasa@ens-lyon.org; Tanasa, Adrian E-mail: adrian.tanasa@ens-lyon.org

    2014-04-15

    The Loop Vertex Expansion (LVE) is a quantum field theory (QFT) method which explicitly computes the Borel sum of Feynman perturbation series. This LVE relies in a crucial way on symmetric tree weights which define a measure on the set of spanning trees of any connected graph. In this paper we generalize this method by defining new tree weights. They depend on the choice of a partition of a set of vertices of the graph, and when the partition is non-trivial, they are no longer symmetric under permutation of vertices. Nevertheless we prove they have the required positivity property to lead to a convergent LVE; in fact we formulate this positivity property precisely for the first time. Our generalized tree weights are inspired by the Brydges-Battle-Federbush work on cluster expansions and could be particularly suited to the computation of connected functions in QFT. Several concrete examples are explicitly given.

  7. Combining Binary Search Trees

    E-print Network

    Demaine, Erik D.

    We present a general transformation for combining a constant number of binary search tree data structures (BSTs) into a single BST whose running time is within a constant factor of the minimum of any “well-behaved” bound ...

  8. Construction of Decision Trees

    E-print Network

    Banks, Edwin Roger

    1970-02-01

    The construction of optimal decision trees for the problem stated within can be accomplished by an exhaustive enumeration. This paper discusses two approaches. The section on heuristic methods gives mostly negative results ...

  9. Trees as energy crops

    SciTech Connect

    Standiford, R.B.; Donaldson, D.R.

    1982-01-01

    A report is presented of studies on the energy production of forest trees in California. The volume yield of the fastest growing species (Eucalyptus) was 23 cubic metres per hectare and energy yield 20 million kcal per hectare per annum.

  10. TREE TRAILS Career Cards

    E-print Network

    Specialist Wildland Firefighter Wildlife Biologist Writer #12;Module 4 TREE TRAILS Instructional Procedures that uses computers to create and maintain data and maps Wildland Firefighter a person puts out a fire

  11. How Trees Can Save Energy.

    ERIC Educational Resources Information Center

    Fazio, James R., Ed.

    1991-01-01

    This document might easily have been called "How To Use Trees To Save Energy". It presents the energy saving advantages of landscaping the home and community with trees. The discussion includes: (1) landscaping advice to obtain the benefits of tree shade; (2) the heat island phenomenon in cities; (3) how and where to properly plant trees for…

  12. Jennifer Ramos The Notable Trees

    E-print Network

    Weston, Nathaniel B.

    Jennifer Ramos The Notable Trees of Villanova University The Importance of VU's Urban Trees Urban trees serve a number of important purposes: they reduce air and noise pollution, reduce soil erosion to sustainability, the campus's many trees play an important role in working towards this commitment. However, even

  13. COMPONENT User's Guide Consensus trees

    E-print Network

    Page, Roderic

    COMPONENT User's Guide Chapter 4 Consensus trees Consensus trees are a convenient way to summarise the agreement between two or more trees. This chapter describes the consensus methods available in COMPONENT subtree (Kubicka et al, 1992; also called the common pruned tree [Finden and Gordon, 1985]). This method

  14. TREES of SCa Public Service of Clemson University S.C. Champion Tree Nomination Form

    E-print Network

    Stuart, Steven J.

    CHAMPION TREES of SCa Public Service of Clemson University S.C. Champion Tree Nomination Form Today's date: ___________________________ Scientific tree name: ________________________________________________ Common tree name: _________________________________________________ Group

  15. TREE TRAILS Trees fascinate us because the oldest among them span many human generations. Trees can be a living

    E-print Network

    1 TREE TRAILS Trees fascinate us because the oldest among them span many human generations. Trees to important events or people in the community. Tree Trails Tree History Goal: Students will research the history of a tree(s) and make connections to the past. Objectives: Students will 1. Investigate a specific

  16. Nearest tree Always go to the closest

    E-print Network

    Nearest tree Always go to the closest tree Largest tree Always go to the tree with the most apples Optimal 1-step forager Maximize rate (= ratio of apples to travel time), but only consider one tree at a time # apples travel time Optimal 2-, 3-step forager Maximize rate over 2-tree (or 3-tree) paths

  17. In this chapter we study infinite trees. The main things we look at are Konig's tree theorem, Aronszajn trees, and Suslin trees.

    E-print Network

    Monk, Don

    14. Trees In this chapter we study infinite trees. The main things we look at are K¨onig's tree theorem, Aronszajn trees, and Suslin trees. A tree is a partially ordered set (T, t T, the set {s T : s tree

  18. Deletion from Okasaki's Red-Black Trees

    E-print Network

    Might, Matt

    Deletion from Okasaki's Red-Black Trees: A Functional Pearl Matt Might University of Utah matt;(: balance : (All (A) ((RBTree A) -> (RBTree A)))) (define (balance tree) (RBTree (RBTree-comparer tree) (balance-helper (RBTree-tree tree)))) (: balance-helper : (All (A) ((Tree A) -> (Tree A)))) (define

  19. Odds-On Trees

    E-print Network

    Bose, Prosenjit; Douieb, Karim; Dujmovic, Vida; King, James; Morin, Pat

    2010-01-01

    Let R^d -> A be a query problem over R^d for which there exists a data structure S that can compute P(q) in O(log n) time for any query point q in R^d. Let D be a probability measure over R^d representing a distribution of queries. We describe a data structure called the odds-on tree, of size O(n^\\epsilon) that can be used as a filter that quickly computes P(q) for some query values q in R^d and relies on S for the remaining queries. With an odds-on tree, the expected query time for a point drawn according to D is O(H*+1), where H* is a lower-bound on the expected cost of any linear decision tree that solves P. Odds-on trees have a number of applications, including distribution-sensitive data structures for point location in 2-d, point-in-polytope testing in d dimensions, ray shooting in simple polygons, ray shooting in polytopes, nearest-neighbour queries in R^d, point-location in arrangements of hyperplanes in R^d, and many other geometric searching problems that can be solved in the linear-decision tree mo...

  20. Tree nut allergens.

    PubMed

    Roux, Kenneth H; Teuber, Suzanne S; Sathe, Shridhar K

    2003-08-01

    Allergic reactions to tree nuts can be serious and life threatening. Considerable research has been conducted in recent years in an attempt to characterize those allergens that are most responsible for allergy sensitization and triggering. Both native and recombinant nut allergens have been identified and characterized and, for some, the IgE-reactive epitopes described. Some allergens, such as lipid transfer proteins, profilins, and members of the Bet v 1-related family, represent minor constituents in tree nuts. These allergens are frequently cross-reactive with other food and pollen homologues, and are considered panallergens. Others, such as legumins, vicilins, and 2S albumins, represent major seed storage protein constituents of the nuts. The allergenic tree nuts discussed in this review include those most commonly responsible for allergic reactions such as hazelnut, walnut, cashew, and almond as well as those less frequently associated with allergies including pecan, chestnut, Brazil nut, pine nut, macadamia nut, pistachio, coconut, Nangai nut, and acorn. PMID:12915766

  1. The Di erences Between Kurepa Trees And Jech Kunen Trees 1 Renling Jin

    E-print Network

    Jin, Renling

    The Di erences Between Kurepa Trees And Jech Kunen Trees 1 Renling Jin Abstract By an !1 tree we mean a tree of power !1 and height !1. An !1 tree is called a Kurepa tree if all its levels are countable and it has more than !1 branches. An !1 tree is called a Jech Kunen tree if it has branches

  2. Heartwood and tree exudates

    SciTech Connect

    Hillis, W.E.

    1987-01-01

    Increasingly, mankind will depend on renewable resources produced at low energy cost - such as forest products. Greater demands will require increased growth as well as utilisation with reduced loss. After a certain age, trees from heartwood containing increased amounts of extractives which are also formed in injured sapwood or are exuded. Their presence can provide trees with resistance to disease and insect attack and they can also affect the efficient utilisation of wood. In this book different facets of heartwood, extractives and exudates are reviewed as a whole for the first time.

  3. A Parallel Tree Code

    E-print Network

    John Dubinski

    1996-03-18

    We describe a new implementation of a parallel N-body tree code. The code is load-balanced using the method of orthogonal recursive bisection to subdivide the N-body system into independent rectangular volumes each of which is mapped to a processor on a parallel computer. On the Cray T3D, the load balance in the range of 70-90\\% depending on the problem size and number of processors. The code can handle simulations with $>$ 10 million particles roughly a factor of 10 greater than allowed in vectorized tree codes.

  4. Optimal Key-Trees for Tree-Based Private Authentication

    E-print Network

    Bencsáth, Boldizsár

    Optimal Key-Trees for Tree-Based Private Authentication Levente Butty´an, Tam´as Holczer, and Istv University of Technology and Economics, Hungary {buttyan, holczer, vajda}@crysys.hu Abstract. Key-tree based the problem of pri- vacy preserving authentication based on symmetric key cryptography. However, in the key

  5. WHAT DO YOU USE TREES FOR? Tree: Paper Birch

    E-print Network

    Ashline, George

    WHAT DO YOU USE TREES FOR? Tree: Paper Birch Scientific Name: Betula Papyrifera Tree# & Location a bark rubbing of the Paper Birch, then brainstorm and create a list of how we can use this bark the Paper Birch outside of the McCarthy Arts Center. · Tape a blank sheet of paper to the bark. · With your

  6. Tree Cross Sections The study of tree rings is called

    E-print Network

    , possibly from not enough water, sunlight, space or nutrients. 2. This tree shows scars where branches have Sections 3. Wide rings could mean the available water, sunlight, space or nutrients allowed the tree fungus is also evident in the sapwood. The fungus is carried by bark beetles and quickens the tree

  7. Can These Trees Be Saved? 

    E-print Network

    Taylor, Eric; Foster, C. Darwin

    2005-10-19

    This publication explains how to determine whether a storm-damaged tree can be saved. If the damage is not severe, most trees will recover in time. Helpful illustrations depict different levels of damage....

  8. FRACTAL TREES WITH SIDE BRANCHING

    E-print Network

    1998-01-10

    system for side branching is introduced, along with the Tokunaga self-similarity ... plants and trees, root systems, bronchial systems, ..... central node to the centers of the eight cubes. Due .... evolutionary trees, the nervous system, and com-.

  9. Flat Tree Oyster (Isognomon alatus)

    USGS Multimedia Gallery

    At high tide, the red bark of the Red Mangrove Trees is submerged, creating a brilliant reflection at the water's surface. Flat Tree Oysters (Isognomon alatus) grow on the upper portions of the roots....

  10. Simplicial matrix-tree theorems

    E-print Network

    Duval, Art M.; Klivans, Caroline J.; Martin, Jeremy L.

    2009-01-01

    We generalize the definition and enumeration of spanning trees from the setting of graphs to that of arbitrary-dimensional simplicial complexes ?, extending an idea due to G. Kalai. We prove a simplicial version of the Matrix-Tree Theorem...

  11. The Fig Tree's Lessons.

    ERIC Educational Resources Information Center

    Hall, Kristen

    1988-01-01

    Describes the dramatization of Katherine Anne Porter's story,"The Fig Tree's Lessons." Discusses the process by which this story was made accessible to an audience of 8- to 12-year-old children. Notes that this program attempts to avoid the simplification of the profound human experience of dealing with death. (KO)

  12. Digging Deeper with Trees.

    ERIC Educational Resources Information Center

    Growing Ideas, 2001

    2001-01-01

    Describes hands-on science areas that focus on trees. A project on leaf pigmentation involves putting crushed leaves in a test tube with solvent acetone to dissolve pigment. In another project, students learn taxonomy by sorting and classifying leaves based on observable characteristics. Includes a language arts connection. (PVD)

  13. Tree-Ties.

    ERIC Educational Resources Information Center

    Gresczyk, Rick

    Created to help students understand how plants were used for food, for medicine, and for arts and crafts among the Ojibwe (Chippewa) Indians, the game Tree-Ties combines earth and social sciences within a specific culture. The game requires mutual respect, understanding, and agreement to succeed. Sounding like the word "treaties", the title is a…

  14. Phylogenics & Tree-Thinking

    ERIC Educational Resources Information Center

    Baum, David A.; Offner, Susan

    2008-01-01

    Phylogenetic trees, which are depictions of the inferred evolutionary relationships among a set of species, now permeate almost all branches of biology and are appearing in increasing numbers in biology textbooks. While few state standards explicitly require knowledge of phylogenetics, most require some knowledge of evolutionary biology, and many…

  15. Arbutus unedo, Strawberry Tree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Encylopedia of Fruit and Nuts is designed as a research reference source on temperate and tropical fruit and nut crops. Strawberry tree or madrone is native to the Mediterranean region of southern Europe (Arbutus unedo L., Ericaceae) with a relict population in Ireland, as well as in North Ameri...

  16. Advisory Note TREE HEALTH

    E-print Network

    pest Advisory Note TREE HEALTH March 2007 Gypsy Moth Lymantria dispar (Lepidoptera: Lymantridae) Gypsy's. When fully grown, gypsy moth larvae (caterpillars) can be up to 70 mm long. They will feed for some people. Life Cycle 1. Fully grown larva feeding on oak Larvae: April- August Gypsy moth larvae

  17. Christmas Tree Category Manual.

    ERIC Educational Resources Information Center

    Bowman, James S.; Turmel, Jon P.

    This manual provides information needed to meet the standards for pesticide applicator certification. Pests and diseases of christmas tree plantations are identified and discussed. Section one deals with weeds and woody plants and the application, formulation and effects of herbicides in controlling them. Section two discusses specific diseases…

  18. Rate of tree carbon accumulation increases continuously with tree size

    USGS Publications Warehouse

    Stephenson, N.L.; Das, A.J.; Condit, R.; Russo, S.E.; Baker, P.J.; Beckman, N.G.; Coomes, D.A.; Lines, E.R.; Morris, W.K.; Rüger, N.; Álvarez, E.; Blundo, C.; Bunyavejchewin, S.; Chuyong, G.; Davies, S.J.; Duque, Á.; Ewango, C.N.; Flores, O.; Franklin, J.F.; Grau, H.R.; Hao, Z.; Harmon, M.E.; Hubbell, S.P.; Kenfack, D.; Lin, Y.; Makana, J.-R.; Malizia, A.; Malizia, L.R.; Pabst, R.J.; Pongpattananurak, N.; Su, S.-H.; Sun, I-F.; Tan, S.; Thomas, D.; van Mantgem, P.J.; Wang, X.; Wiser, S.K.; Zavala, M.A.

    2014-01-01

    Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage—increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to understand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

  19. The Hopi Fruit Tree Book.

    ERIC Educational Resources Information Center

    Nyhuis, Jane

    Referring as often as possible to traditional Hopi practices and to materials readily available on the reservation, the illustrated booklet provides information on the care and maintenance of young fruit trees. An introduction to fruit trees explains the special characteristics of new trees, e.g., grafting, planting pits, and watering. The…

  20. Building up rhetorical structure trees

    SciTech Connect

    Marcu, D.

    1996-12-31

    I use the distinction between the nuclei and the satellites that pertain to discourse relations to introduce a compositionality criterion for discourse trees. I provide a first-order formalization of rhetorical structure trees and, on its basis, I derive an algorithm that constructs all the valid rhetorical trees that can be associated with a given discourse.

  1. Machine Learning Srihari Decision Trees

    E-print Network

    Machine Learning Srihari 1 Decision Trees Sargur Srihari srihari@cedar.buffalo.edu #12;Machine the unobserved examples · Inductive bias is a preference for small trees over large trees #12;Machine Learning #12;Machine Learning Srihari 4 Learning Data Day Outlook Temp Humidity Wind PlayTennis D1 Sunny Hot

  2. Our Air: Unfit for Trees.

    ERIC Educational Resources Information Center

    Dochinger, Leon S.

    To help urban, suburban, and rural tree owners know about air pollution's effects on trees and their tolerance and intolerance to pollutants, the USDA Forest Service has prepared this booklet. It answers the following questions about atmospheric pollution: Where does it come from? What can it do to trees? and What can we do about it? In addition,…

  3. Genetic conservation of native trees

    E-print Network

    Genetic conservation of native trees Scott McG. Wilson1 and C. J. A. Samuel Over recent years, the genetic conservation of British native tree populations has become an increasingly important part of the work of Tree Improvement Branch (TIB). This has been in response to a greater interest from forestry

  4. Singular spectrum for radial trees

    E-print Network

    Jonathan Breuer; Rupert L. Frank

    2008-06-03

    We prove several results showing that absolutely continuous spectrum for the Laplacian on radial trees is a rare event. In particular, we show that metric trees with unbounded edges have purely singular spectrum and that generically (in the sense of Baire) radial trees have purely singular continuous spectrum.

  5. Orthogonal Decision Trees Hillol Kargupta

    E-print Network

    Kargupta, Hilol

    1 Orthogonal Decision Trees Hillol Kargupta ¢¡ , Byung-Hoon Park £ , Haimonti Dutta Department orthogonal decision trees that offer an effective way to construct a redundancy- free, accurate, and meaningful representation of large decision-tree-ensembles often created by popular techniques

  6. Game Trees for Decision Analysis

    E-print Network

    Shenoy, Prakash P.

    1998-04-01

    Game trees (or extensive-form games) were first defined by von Neumann and Morgenstern in 1944. In this paper, we examine the use of game trees for representing Bayesian decision problems. We propose a method for solving game trees using local...

  7. Orthogonal Decision Trees Hillol Kargupta

    E-print Network

    Kargupta, Hilol

    Orthogonal Decision Trees Hillol Kargupta and Haimonti Dutta Department of Computer Science¡ hillol, hdutta1¢ @cs.umbc.edu Abstract This paper introduces orthogonal decision trees that of- fer an effective way to construct a redundancy-free, accu- rate, and meaningful representation of large decision-tree

  8. van Emde Boas Trees -Dynamic Predecessors

    E-print Network

    Zwick, Uri

    van Emde Boas Trees - Dynamic Predecessors Uri Zwick Tel Aviv University #12;Insert Delete Find > } = | , = | = #12;van Emde Boas Trees A vEB tree representing consists of: ­ word size ­ the minimal keyEB tree for ( - , , ) #12;van Emde Boas Trees Are , better names than , ? #12;van Emde Boas Trees

  9. Red-black Tree Jingjing Xia

    E-print Network

    Chen, Yangjun

    Advanced Algorithm Design Red-black Tree Jingjing Xia #12;Red-Black Tree A red-black tree is a binary search tree, and each node contains one extra field: its color, it can be either black or red of the binary search tree. If a binary search tree satisfies all the following red-black properties, it is a red-black

  10. Gene tree correction for reconciliation and species tree inference

    PubMed Central

    2012-01-01

    Background Reconciliation is the commonly used method for inferring the evolutionary scenario for a gene family. It consists in “embedding” inferred gene trees into a known species tree, revealing the evolution of the gene family by duplications and losses. When a species tree is not known, a natural algorithmic problem is to infer a species tree from a set of gene trees, such that the corresponding reconciliation minimizes the number of duplications and/or losses. The main drawback of reconciliation is that the inferred evolutionary scenario is strongly dependent on the considered gene trees, as few misplaced leaves may lead to a completely different history, with significantly more duplications and losses. Results In this paper, we take advantage of certain gene trees’ properties in order to preprocess them for reconciliation or species tree inference. We flag certain duplication vertices of a gene tree, the “non-apparent duplication” (NAD) vertices, as resulting from the misplacement of leaves. In the case of species tree inference, we develop a polynomial-time heuristic for removing the minimum number of species leading to a set of gene trees that exhibit no NAD vertices with respect to at least one species tree. In the case of reconciliation, we consider the optimization problem of removing the minimum number of leaves or species leading to a tree without any NAD vertex. We develop a polynomial-time algorithm that is exact for two special classes of gene trees, and show a good performance on simulated data sets in the general case. PMID:23167951

  11. Rate of tree carbon accumulation increases continuously with tree size.

    PubMed

    Stephenson, N L; Das, A J; Condit, R; Russo, S E; Baker, P J; Beckman, N G; Coomes, D A; Lines, E R; Morris, W K; Rüger, N; Alvarez, E; Blundo, C; Bunyavejchewin, S; Chuyong, G; Davies, S J; Duque, A; Ewango, C N; Flores, O; Franklin, J F; Grau, H R; Hao, Z; Harmon, M E; Hubbell, S P; Kenfack, D; Lin, Y; Makana, J-R; Malizia, A; Malizia, L R; Pabst, R J; Pongpattananurak, N; Su, S-H; Sun, I-F; Tan, S; Thomas, D; van Mantgem, P J; Wang, X; Wiser, S K; Zavala, M A

    2014-03-01

    Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle--particularly net primary productivity and carbon storage--increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree's total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence. PMID:24429523

  12. From Gene to Organismal Phylogeny: Reconciled Trees and the Gene Tree/Species Tree Problem

    E-print Network

    Page, Roderic

    From Gene to Organismal Phylogeny: Reconciled Trees and the Gene Tree/Species Tree Problem Roderic The processes of gene duplication, loss, and lineage sorting can result in incongruence between the phylog- enies of genes and those of species. This incongruence complicates the task of inferring the latter from

  13. Global Value Trees

    PubMed Central

    Zhu, Zhen; Puliga, Michelangelo; Cerina, Federica; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    The fragmentation of production across countries has become an important feature of the globalization in recent decades and is often conceptualized by the term “global value chains” (GVCs). When empirically investigating the GVCs, previous studies are mainly interested in knowing how global the GVCs are rather than how the GVCs look like. From a complex networks perspective, we use the World Input-Output Database (WIOD) to study the evolution of the global production system. We find that the industry-level GVCs are indeed not chain-like but are better characterized by the tree topology. Hence, we compute the global value trees (GVTs) for all the industries available in the WIOD. Moreover, we compute an industry importance measure based on the GVTs and compare it with other network centrality measures. Finally, we discuss some future applications of the GVTs. PMID:25978067

  14. Global value trees.

    PubMed

    Zhu, Zhen; Puliga, Michelangelo; Cerina, Federica; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    The fragmentation of production across countries has become an important feature of the globalization in recent decades and is often conceptualized by the term "global value chains" (GVCs). When empirically investigating the GVCs, previous studies are mainly interested in knowing how global the GVCs are rather than how the GVCs look like. From a complex networks perspective, we use the World Input-Output Database (WIOD) to study the evolution of the global production system. We find that the industry-level GVCs are indeed not chain-like but are better characterized by the tree topology. Hence, we compute the global value trees (GVTs) for all the industries available in the WIOD. Moreover, we compute an industry importance measure based on the GVTs and compare it with other network centrality measures. Finally, we discuss some future applications of the GVTs. PMID:25978067

  15. Insert tree completion system

    SciTech Connect

    Brands, K.W.; Ball, I.G.; Cegielski, E.J.; Gresham, J.S.; Saunders, D.N.

    1982-09-01

    This paper outlines the overall project for development and installation of a low-profile, caisson-installed subsea Christmas tree. After various design studies and laboratory and field tests of key components, a system for installation inside a 30-in. conductor was ordered in July 1978 from Cameron Iron Works Inc. The system is designed to have all critical-pressure-containing components below the mudline and, with the reduced profile (height) above seabed, provides for improved safety of satellite underwater wells from damage by anchors, trawl boards, and even icebergs. In addition to the innovative nature of the tree design, the completion includes improved 3 1/2-in. through flowline (TFL) pumpdown completion equipment with deep set safety valves and a dual detachable packer head for simplified workover capability. The all-hydraulic control system incorporates a new design of sequencing valve for both Christmas tree control and remote flowline connection. A semisubmersible drilling rig was used to initiate the first end flowline connection at the wellhead for subsequent tie-in to the prelaid, surface-towed, all-welded subsea pipeline bundle.

  16. Top-Working Pecan Trees

    E-print Network

    Kyle, E. J.

    1916-01-01

    and Mechanical College of Texas (In cooperation with the United States Department of Agriculture.) ,I' APRIL, 1916 EXTENSION SERVICE No. B-21 TOP-WORKING PECAN TREES Address CLARENCE OUSLEY Director of Extension Service, College Station, Texas TOP WORKING PECAN... TREES By E. J. Kyle, Professor of Horticulture, Dean of the School of Agriculture, Agricultural and Mechanical College of Texas. Top-working pecan trees has passed beyond the experimental stage. Some of the methods employed during the experimental period...

  17. Barking up the Right Tree

    ERIC Educational Resources Information Center

    Houston, Paul D.

    2006-01-01

    There is a childhood saying about a confused dog who thinks he sees a possum in a tree. The problem is that the possum is actually in a different tree so the dog barks up the wrong tree. American education is constantly playing both dog and possum. Sometimes they are the prey, and sometimes they are just confused about what and where the prey is.…

  18. Collapse of loaded fractal trees

    NASA Astrophysics Data System (ADS)

    Turcotte, D. L.; Smalley, R. F.; Solla, Sara A.

    1985-02-01

    Mandelbrot1 has argued that a wide range of natural objects and phenomena are fractals; examples of fractal trees include actual trees, plants such as a cauliflower, river systems and the cardiovascular system. Here we apply the renormalization group approach2 to the collapse of fractal trees, which may be applicable to a variety of problems including cardiac arrest, failure of bronchial systems, failure of electrical distribution systems and the instability resulting in earthquakes.

  19. Human decision error (HUMDEE) trees

    SciTech Connect

    Ostrom, L.T.

    1993-08-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision.

  20. Street Tree Inventory Report and Recommendations

    E-print Network

    and planting. * Conduct an annual Arbor Day celebration and involve local groups. * Craft a public tree care Street Tree Care Replacement Value Street Tree Values Recommendations A. Data Collection Form B. Species% require only routine care. * An estimated 2,200 public trees and 1,900 private trees have limbs

  1. Sugar Maple Tree Photo by Matt Hajdun

    E-print Network

    Ashline, George

    Sugar Maple Tree Photo by Matt Hajdun Did you know that the Sugar Maple Tree can reach heights of 130 feet or more and live to be very old. Activity for Saplings Story of a Sugar Maple Materials. · Read Tell Me, Tree. · Collect a few Sugar Maple leaves from the tree. · Look at the tree

  2. Small integral trees A. E. Brouwer

    E-print Network

    Brouwer, Andries E.

    Small integral trees A. E. Brouwer 2007-12-31 Abstract We give a table with all integral trees on at most 50 vertices, and characterize integral trees with a single eigenvalue 0. 1 Integral trees A finite graph is called integral if the spectrum of its adjacency matrix has only integral eigenvalues. A tree

  3. COMPONENT User's Guide Maps between trees

    E-print Network

    Page, Roderic

    COMPONENT User's Guide Chapter 7 Maps between trees This chapter describes tree mapping routines in COMPONENT. These routines allow you to map gene trees onto species trees, parasite phylogenies onto host phylogenies, and taxon cladograms onto area cladograms. Overview This section introduces some basics of tree

  4. Simaroubaceae (Quassia family) Tree-of-heaven

    E-print Network

    Simaroubaceae (Quassia family) Tree-of-heaven Ailanthus altissima (Mill.) Swingle Life cycle Fast leaves emit an unpleasant odor. Glands on underside of leaflet teeth. Tree-of-heaven sapling. Tree-of-heaven Seeds and prolific vegetative sprouts. Tree-of-heaven continued Tree-of-heaven weedy habit. #12;

  5. DIF Trees: Using Classification Trees to Detect Differential Item Functioning

    ERIC Educational Resources Information Center

    Vaughn, Brandon K.; Wang, Qiu

    2010-01-01

    A nonparametric tree classification procedure is used to detect differential item functioning for items that are dichotomously scored. Classification trees are shown to be an alternative procedure to detect differential item functioning other than the use of traditional Mantel-Haenszel and logistic regression analysis. A nonparametric…

  6. Relating phylogenetic trees to transmission trees of infectious disease outbreaks.

    PubMed

    Ypma, Rolf J F; van Ballegooijen, W Marijn; Wallinga, Jacco

    2013-11-01

    Transmission events are the fundamental building blocks of the dynamics of any infectious disease. Much about the epidemiology of a disease can be learned when these individual transmission events are known or can be estimated. Such estimations are difficult and generally feasible only when detailed epidemiological data are available. The genealogy estimated from genetic sequences of sampled pathogens is another rich source of information on transmission history. Optimal inference of transmission events calls for the combination of genetic data and epidemiological data into one joint analysis. A key difficulty is that the transmission tree, which describes the transmission events between infected hosts, differs from the phylogenetic tree, which describes the ancestral relationships between pathogens sampled from these hosts. The trees differ both in timing of the internal nodes and in topology. These differences become more pronounced when a higher fraction of infected hosts is sampled. We show how the phylogenetic tree of sampled pathogens is related to the transmission tree of an outbreak of an infectious disease, by the within-host dynamics of pathogens. We provide a statistical framework to infer key epidemiological and mutational parameters by simultaneously estimating the phylogenetic tree and the transmission tree. We test the approach using simulations and illustrate its use on an outbreak of foot-and-mouth disease. The approach unifies existing methods in the emerging field of phylodynamics with transmission tree reconstruction methods that are used in infectious disease epidemiology. PMID:24037268

  7. Sussing Merger Trees: A proposed Merger Tree data format

    E-print Network

    Thomas, Peter A; Tweed, Dylan; Benson, Andrew J; Croton, Darren; Elahi, Pascal; Henriques, Bruno; Iliev, Ilian T; Knebe, Alexander; Lux, Hanni; Mao, Yao-Yuan; Neyrinck, Mark; Pearce, Frazer R; Rodriguez-Gomez, Vicente; Schneider, Aurel; Srisawat, Chaichalit

    2015-01-01

    We propose a common terminology for use in describing both temporal merger trees and spatial structure trees for dark-matter halos. We specify a unified data format in HDF5 and provide example I/O routines in C, FORTRAN and PYTHON.

  8. Red-Black Trees 1 2004 Goodrich, Tamassia Red-Black Trees

    E-print Network

    Alechina, Natasha

    Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z #12;Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison with its associated (2,4) tree

  9. Two Trees: Migrating Fault Trees to Decision Trees for Real Time Fault Detection on International Space Station

    NASA Technical Reports Server (NTRS)

    Lee, Charles; Alena, Richard L.; Robinson, Peter

    2004-01-01

    We started from ISS fault trees example to migrate to decision trees, presented a method to convert fault trees to decision trees. The method shows that the visualizations of root cause of fault are easier and the tree manipulating becomes more programmatic via available decision tree programs. The visualization of decision trees for the diagnostic shows a format of straight forward and easy understands. For ISS real time fault diagnostic, the status of the systems could be shown by mining the signals through the trees and see where it stops at. The other advantage to use decision trees is that the trees can learn the fault patterns and predict the future fault from the historic data. The learning is not only on the static data sets but also can be online, through accumulating the real time data sets, the decision trees can gain and store faults patterns in the trees and recognize them when they come.

  10. Distributed Merge Trees

    SciTech Connect

    Morozov, Dmitriy; Weber, Gunther

    2013-01-08

    Improved simulations and sensors are producing datasets whose increasing complexity exhausts our ability to visualize and comprehend them directly. To cope with this problem, we can detect and extract significant features in the data and use them as the basis for subsequent analysis. Topological methods are valuable in this context because they provide robust and general feature definitions. As the growth of serial computational power has stalled, data analysis is becoming increasingly dependent on massively parallel machines. To satisfy the computational demand created by complex datasets, algorithms need to effectively utilize these computer architectures. The main strength of topological methods, their emphasis on global information, turns into an obstacle during parallelization. We present two approaches to alleviate this problem. We develop a distributed representation of the merge tree that avoids computing the global tree on a single processor and lets us parallelize subsequent queries. To account for the increasing number of cores per processor, we develop a new data structure that lets us take advantage of multiple shared-memory cores to parallelize the work on a single node. Finally, we present experiments that illustrate the strengths of our approach as well as help identify future challenges.

  11. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF... PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of trees...

  12. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF... PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of trees...

  13. Non-crossing Trees are Almost Conditioned Galton-Watson trees1

    E-print Network

    Marckert, Jean-François

    Non-crossing Trees are Almost Conditioned Galton-Watson trees1 Jean-Fran¸cois Marckert Alois-10, A - 1040 Wien, Austria alois.panholzer@tuwien.ac.at ABSTRACT: A non-crossing tree (NC-tree) is a tree drawn seg- ments that do not cross. In this paper, we show that NC-trees with size n are conditioned Galton

  14. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF... PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of trees...

  15. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF... PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of trees...

  16. A New Pruning Method for Solving Decision Trees and Game Trees

    E-print Network

    Shenoy, Prakash P.

    1995-08-01

    The main goal of this paper is to describe a newpruning method for solving decision trees and game trees. The pruning method for decision trees suggests a slight variant of decision trees that we call scenario trees. In scenario trees, we do...

  17. Decision Trees Decision trees are a popular method for classifying objects by means

    E-print Network

    Hamburg,.Universität

    1 1 Decision Trees Decision trees are a popular method for classifying objects by means of a sequence of tests of feature values following a tree structure. Example : Decision tree for classifying A decision tree is a tree where: · the non-leaf nodes are labeled with attributes, · all arcs out of a node

  18. On the Number of Ranked Species Trees Producing Anomalous Ranked Gene Trees

    E-print Network

    Rosenberg, Noah

    On the Number of Ranked Species Trees Producing Anomalous Ranked Gene Trees Filippo Disanto demonstrated the existence of anomalous ranked gene trees (ARGTs), ranked gene trees that are more probable than the ranked gene tree that accords with the ranked species tree. Here, to improve

  19. Reconciling a Gene Tree to a Species Tree Under the Duplication Paola Bonizzoni

    E-print Network

    Della Vedova, Gianluca

    Reconciling a Gene Tree to a Species Tree Under the Duplication Cost Model Paola Bonizzoni Gianluca from evolutionary trees representing the relationships between distinct gene families is of great of minimum tree that reconciles a gene tree and a species tree is correct. We answer affirmatively

  20. Oak trees havevariedeffect on landvalues

    E-print Network

    County seat, Santa Rosa, is about 60 miles from San Francisco. The coun- ty's population of 340 of several blue oak stands with different tree density were taken in July 1986 in Briones Regional Park for five blue oak stands, Briones Regional Park, Contra Costa county Trees Basal Volume area per Crown acre

  1. The tree of one percent

    PubMed Central

    Dagan, Tal; Martin, William

    2006-01-01

    Two significant evolutionary processes are fundamentally not tree-like in nature - lateral gene transfer among prokaryotes and endosymbiotic gene transfer (from organelles) among eukaryotes. To incorporate such processes into the bigger picture of early evolution, biologists need to depart from the preconceived notion that all genomes are related by a single bifurcating tree. PMID:17081279

  2. Climate change & street trees project

    E-print Network

    Climate change & street trees project Social Research Report The social and cultural values Group as part of the Climate change and street trees project, funded by the Forestry Commission with changing socio-economics and/or demographics, but little evidence exists relating

  3. Looking/Learning Drawing: Trees.

    ERIC Educational Resources Information Center

    Hurwitz, Al; Blume, Sharon

    1985-01-01

    Secondary students are asked to study and compare three reproductions--Van Gogh's "Grove of Cypresses," Da Vinci's "Study of a Tree," and Mondrian's "Tree II." The activity will help students develop their powers of observation and analysis, powers that can be applied to their own drawings. (RM)

  4. Tree Hydraulics: How Sap Rises

    ERIC Educational Resources Information Center

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  5. 75 FR 25103 - Tree Assistance Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ...Corporation 7 CFR Part 1416 RIN 0560-AH96 Tree Assistance Program AGENCY: Farm Service...implements specific requirements for the Tree Assistance Program (TAP) authorized by...assistance to eligible orchardists and nursery tree growers to replant or rehabilitate...

  6. Latent Tree Classifier , Nevin L. Zhang2

    E-print Network

    Zhang, Nevin L.

    on latent tree models. A latent tree model (LTM) [23] is a tree-structured Bayesian network in which be different across classes. Therefore, we build an LTM for each class. We refer to the collection of LTMs plus

  7. Optimal Decision Trees Kristin P. Bennett \\Lambda

    E-print Network

    Mitchell, John E.

    Optimal Decision Trees Kristin P. Bennett \\Lambda Jennifer A. Blue Department of Mathematical an Extreme Point Tabu Search (EPTS) algorithm that constructs globally optimal decision trees for classification problems. Typically, decision tree algorithms are greedy. They optimize the misclassification

  8. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture...DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information...

  9. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture...DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information...

  10. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture...DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information...

  11. Quantum Computation and Decision Trees

    E-print Network

    Edward Farhi; Sam Gutmann

    1998-03-20

    Many interesting computational problems can be reformulated in terms of decision trees. A natural classical algorithm is to then run a random walk on the tree, starting at the root, to see if the tree contains a node n levels from the root. We devise a quantum mechanical algorithm that evolves a state, initially localized at the root, through the tree. We prove that if the classical strategy succeeds in reaching level n in time polynomial in n, then so does the quantum algorithm. Moreover, we find examples of trees for which the classical algorithm requires time exponential in n, but for which the quantum algorithm succeeds in polynomial time. The examples we have so far, however, could also be solved in polynomial time by different classical algorithms.

  12. A Cost Benefit Analysis of Urban Trees

    SciTech Connect

    Akbari, Hashem

    1997-09-01

    Urban shade trees offer significant benefits in reducing building air- conditioning and improving urban air quality by reducing smog. The savings associated with these benefits varies by climate regions and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree planting programs can be designed offer savings to communities that plant trees.

  13. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K.; Warnow, T.J.

    1993-03-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n{sup 3}) time and from POM experiments in O(n{sup 4}) time.

  14. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K. ); Warnow, T.J. )

    1993-01-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n[sup 3]) time and from POM experiments in O(n[sup 4]) time.

  15. Terrestrial apes and phylogenetic trees

    PubMed Central

    Arsuaga, Juan Luis

    2010-01-01

    The image that best expresses Darwin’s thinking is the tree of life. However, Darwin’s human evolutionary tree lacked almost everything because only the Neanderthals were known at the time and they were considered one extreme expression of our own species. Darwin believed that the root of the human tree was very deep and in Africa. It was not until 1962 that the root was shown to be much more recent in time and definitively in Africa. On the other hand, some neo-Darwinians believed that our family tree was not a tree, because there were no branches, but, rather, a straight stem. The recent years have witnessed spectacular discoveries in Africa that take us close to the origin of the human tree and in Spain at Atapuerca that help us better understand the origin of the Neanderthals as well as our own species. The final form of the tree, and the number of branches, remains an object of passionate debate. PMID:20445090

  16. Through bore subsea christmas trees

    SciTech Connect

    Huber, D.S.; Simmers, G.F.C.; Johnson, C.S.

    1985-01-01

    The workovers of subsea completed wells are expensive and time consuming as even the most routine tasks must be carried out by a semi-submersible. This paper describes the economic, safety and operational advantages which led to the development and successful first installation of 'through bore' subsea production trees. The conventional wet subsea trees have proved to be very reliable over the past ten years of operation in the Argyll, Duncan and Innes fields, however the completion strings require pulling on the average about once every three to five years. The conventional subsea tree/tubing hanger set up design requires the tree to be tripped and a rig BOP stack run to pull the tubing. This operation is time consuming, very weather sensitive and leaves the well temporarily without a well control stack on the wellhead. The 7 1/16'' 'through bore' subsea tree was developed to minimize the tubing pulling workover time and several trees have been run successfully since the latter part of 1984. The time saving on a tubing pulling workover is three days. In addition, the design considerably reduces the hazards and equipment damage risk inherent in the conventional design. Hamilton Brothers and National Supply Company in Aberdeen designed the equipment which must be considered a new generation of subsea production trees.

  17. Tree-growth analyses to estimate tree species' drought tolerance.

    PubMed

    Eilmann, Britta; Rigling, Andreas

    2012-02-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species. PMID:22363071

  18. Falls from trees and tree associated injuries in rural Melanesians.

    PubMed

    Barss, P; Dakulala, P; Doolan, M

    Falls from trees and other tree related injuries are the most common cause of trauma in some parts of rural Melanesia. A four year review of all admissions for trauma to the Provincial Hospital at Alotau, Milne Bay Province, Papua New Guinea, showed that 27% were due to falls from trees, and a further 10% were due to related injuries, such as being struck by a falling branch or a coconut. A questionnaire distributed to rural health centres showed that during the study period at least 28 villagers died from falls from trees before reaching hospital. Head and chest trauma were common causes of death. Many injured patients were boys. Forearm fractures were the most common injuries, but more serious injuries were also frequently encountered. Trees responsible for most deaths and injuries included the coconut palm, betel palm, mango, and breadfruit. There are many strategies for preventing such injuries; perhaps the most important is to stop small boys climbing tall trees. Such falls are a serious occupational hazard for many subsistence farmers. PMID:6440619

  19. Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative

    NASA Astrophysics Data System (ADS)

    Pincetl, Stephanie

    2010-02-01

    Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic—living—infrastructure has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been written on the process of implementing urban tree planting programs. The investigative methods were primarily qualitative, involving interviews, attending meetings and conducting literature reviews. Results indicate that multiple nonprofit and city agency programs are involved in planting and maintaining trees and this has required coordination among groups that here-to-fore were unaccustomed to having to collaborate. The main finding that emerge from this research is that the implementation of such a program in Los Angeles is more complicated than it may seem due to several interacting factors: the need to rely on multiple public and private organizations to put trees into the ground and to maintain them; coordination of these multiple efforts must be centralized, but requires a great deal of time and effort and maybe resisted by some of the partners; funding for planting and long term maintenance must be pieced together from multiple sources; acceptance of trees by residents varies by neighborhood as does tree canopy cover; appropriate nursery supply can be limited; the location of the program within the city administration is determined by who initiates the program.

  20. Learning Latent Tree Graphical Models

    E-print Network

    Choi, Myung Jin

    We study the problem of learning a latent tree graphical model where samples are available only from a subset of variables. We propose two consistent and computationally efficient algorithms for learning minimal latent ...

  1. Sugar Maple Tree Photo by Matt Hajdun

    E-print Network

    Ashline, George

    Sugar Maple Tree Photo by Matt Hajdun Did you know the Sugar Maple tree is Vermont's State tree? Sugar Maples have a "U" shaped sinus, and the neighboring tree, the Norway Maple, has a V shaped one, there is white residue on the stem and not on the Sugar Maple. Activity for Seedlings Bark Rubbing Poem Materials

  2. How To Select and Plant a Tree.

    ERIC Educational Resources Information Center

    Fazio, James R., Ed.

    1991-01-01

    This bulletin furnishes information about selecting and planting trees. The tree selection process includes being aware of the physical characteristics of bare root seedlings, containerized seedlings, balled and burlapped, or potted trees and determining the proper size and root ball proportions. The section on tree planting discusses how to: (1)…

  3. Tunnel of the California Tunnel Tree

    USGS Multimedia Gallery

    In this image, the tunnel through the California Tunnel Tree may be seen. The tunnel was cut through the giant sequoia tree in 1895 to allow coaches, and eventually cars, to drive through the tree as part of a marketing stunt. The California Tunnel Tree is the only living giant sequoia with a t...

  4. Learning the Trees By Howard Nemerov

    E-print Network

    1 Poem Links Learning the Trees By Howard Nemerov http://www.poetryfoundation.org/poetrymagazine/poem/22392 Trees By Joyce Kilmer http://www.poetryfoundation.org/poetrymagazine/poem/1947 Native Trees By W. S. Merwin http://www.poetryfoundation.org/poem/171876 Winter Trees By William Carlos Williams http

  5. A Novel Approach for Compressing Phylogenetic Trees

    E-print Network

    Williams, Tiffani

    A Novel Approach for Compressing Phylogenetic Trees Suzanne J. Matthews, Seung-Jin Sul, and Tiffani,sulsj,tlw}@cse.tamu.edu Abstract. Phylogenetic trees are tree structures that depict relation- ships between organisms. Popular analysis techniques often produce large collections of candidate trees, which are expensive to store. We

  6. Decision Tree Learning Goals for the lecture

    E-print Network

    Page Jr., C. David

    Decision Tree Learning #12;Goals for the lecture you should understand the following concepts · the decision tree representation · the standard top-down approach to learning a tree · Occam's razor · entropy and information gain · types of decision-tree splits · test sets and unbiased estimates of accuracy · overfitting

  7. Boolean Decision trees Problems and Results,

    E-print Network

    Saks, Michael

    Boolean Decision trees Problems and Results, Old and New Michael Saks, Rutgers University #12;· Deterministic Decision Trees · Randomized Decision Trees (RDTs) and a new lower bound · Proof of lower bound ­ Influences of boolean functions ­ Influences­Decision Tree connection theorem ­ Deducing the lower bound

  8. Quantum Simulation of Phylogenetic Trees

    E-print Network

    Demosthenes Ellinas; Peter Jarvis

    2011-05-09

    Quantum simulations constructing probability tensors of biological multi-taxa in phylogenetic trees are proposed, in terms of positive trace preserving maps, describing evolving systems of quantum walks with multiple walkers. Basic phylogenetic models applying on trees of various topologies are simulated following appropriate decoherent quantum circuits. Quantum simulations of statistical inference for aligned sequences of biological characters are provided in terms of a quantum pruning map operating on likelihood operator observables, utilizing state-observable duality and measurement theory.

  9. Millersville University's Trees of Distinction

    E-print Network

    Hardy, Christopher R.

    -04-17 #12;#3: Sycamore, American plane (Platanus occidentalis) 2014-06-03 #12;#4: Male Ginkgo, Maidenhair tree (Ginkgo biloba) 2014-05-08 #12;#5: Balsam fir (Abies balsamea) 2014-04-24 #12;#6: Southern (Juglans regia) 2014-05-22 #12;#18: Female Ginkgo, Maidenhair tree (Ginkgo biloba) 2014-06-14 #12;#19: Dawn

  10. Fault Tree Analysis: A Bibliography

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Fault tree analysis is a top-down approach to the identification of process hazards. It is as one of the best methods for systematically identifying an graphically displaying the many ways some things can go wrong. This bibliography references 266 documents in the NASA STI Database that contain the major concepts. fault tree analysis, risk an probability theory, in the basic index or major subject terms. An abstract is included with most citations, followed by the applicable subject terms.

  11. Improvements to a Class of Distance Matrix Methods for Inferring Species Trees from Gene Trees

    E-print Network

    Rosenberg, Noah

    Improvements to a Class of Distance Matrix Methods for Inferring Species Trees from Gene Trees available for inferring species trees from gene trees, the GLASS method of Mossel and Roch (2010 branch length estimates. Further, GLASS and STEAC have been shown to be consistent estimators of tree

  12. High-Dimensional Structure Learning of Graphical Models: Trees, Latent Trees & Beyond

    E-print Network

    Anandkumar, Animashree

    High-Dimensional Structure Learning of Graphical Models: Trees, Latent Trees & Beyond Anima Tan, and Alan Willsky. UIUC Seminar Anima Anandkumar (UCI) Trees, Latent Trees & Beyond 11/08/2010 1 / 52 #12;Graphical Models: Motivation Example: Contextual Object Recognition SKY ROAD AREA TREE CAR CAR

  13. A SIMPLE BIJECTION BETWEEN A SUBCLASS OF 2-BINARY TREES AND TERNARY TREES

    E-print Network

    Wagner, Stephan

    NOTE A SIMPLE BIJECTION BETWEEN A SUBCLASS OF 2-BINARY TREES AND TERNARY TREES HELMUT PRODINGER We consider the subclass of 2-binary trees, where · nodes are labelled black or white, · the root is labelled] that these trees are in bijection with ternary trees (and henceforth enumerated by 1 2n+1 3n n ). In this note we

  14. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests...PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of...

  15. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests...PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of...

  16. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests...PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of...

  17. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests...PRODUCTS General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions of...

  18. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests...TIMBER General Provisions § 223.4 Exchange of trees or portions of trees. Trees or portions...

  19. Generic physical protection logic trees

    SciTech Connect

    Paulus, W.K.

    1981-10-01

    Generic physical protection logic trees, designed for application to nuclear facilities and materials, are presented together with a method of qualitative evaluation of the trees for design and analysis of physical protection systems. One or more defense zones are defined where adversaries interact with the physical protection system. Logic trees that are needed to describe the possible scenarios within a defense zone are selected. Elements of a postulated or existing physical protection system are tagged to the primary events of the logic tree. The likelihood of adversary success in overcoming these elements is evaluated on a binary, yes/no basis. The effect of these evaluations is propagated through the logic of each tree to determine whether the adversary is likely to accomplish the end event of the tree. The physical protection system must be highly likely to overcome the adversary before he accomplishes his objective. The evaluation must be conducted for all significant states of the site. Deficiencies uncovered become inputs to redesign and further analysis, closing the loop on the design/analysis cycle.

  20. Microwave sensing of tree trunks

    NASA Astrophysics Data System (ADS)

    Jezova, Jana; Mertens, Laurence; Lambot, Sebastien

    2015-04-01

    The main subject of this research is the observation of the inner part of living tree trunks using ground-penetrating radar (GPR). Trees are everyday part of human life and therefore it is important to pay attention to the tree conditions. The most obvious consequence of the poor tree condition is dead or injury caused by falling tree. The trunk internal structure is divided into three main parts: heartwood, sapwood and bark, which make this medium highly anisotropic and heterogeneous. Furthermore, the properties of the wood are not only specie-dependent but also depend on genetic and on environmental conditions. In urban areas the main problem for the stability of the trees relies in the apparition of decays provoked by fungi, insect or birds. This results in cavities or decreasing of the support capacity of the tree. GPR has proved itself to be a very powerful electromagnetic tool for non-destructive detection of buried objects. Since the beginning of the 20th century it has been used in several different areas (archaeology, landmine detection, civil engineering, ...). GPR uses the principle of the scattering of the electromagnetic waves that are radiated from a transmitting antenna. Then the waves propagate through the medium and are reflected from the object and then they are received by a receiving antenna. The velocity of the scattered signal is determined primarily by the permittivity of the material. The optimal functionality of the GPR was investigated using the numerical simulation tool gprMax2D. This tool is based on a Finite-Difference Time-Domain (FDTD) numerical model. Subsequently, the GPR functionality was tested using the laboratory model of a decayed tree trunk. Afterwards, the results and lessons learnt in the simplified tests will be used in the processing of the real data and will help to achieve deeper understanding of them. The laboratory model of the tree trunk was made by plastic or carton pipes and filled by sand. Space inside the model was divided into three sections to separate parts with different moisture (heartwood and sapwood) or empty space (decays). For easier manipulation with the antenna we developed a special ruler for measuring the distance along the scans. Instead of the surveying wheel we read the distance with a camera, which was fixed on the antenna and focused on the ruler with a binary pattern. Hence, during whole measurement and the data processing we were able to identify an accurate position on the tree in view of the scan. Some preliminary measurements on the trees were also conducted. They were performed using a GSSI 900 MHz antenna. Several tree species (beech, horse-chestnut, birch, ...) in Louvain-la-Neuve and Brussels, Belgium, have been investigated to see the internal structure of the tree decays. The measurements were carried out mainly by circumferential measurement around the trunk and also by vertical measurement along the trunk for approximate detection of the cavity. The comparison between the numerical simulations, simplified tree trunk model and real data from trees is presented. This research is funded by the Fonds de la Recherche Scientifique (FNRS, Belgium) and benefits from networking activities carried out within the EU COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar".

  1. Parallel TreeSPH

    NASA Astrophysics Data System (ADS)

    Davé, Romeel; Dubinski, John; Hernquist, Lars

    1997-08-01

    We describe PTreeSPH, a gravity treecode combined with an SPH hydrodynamics code designed for parallel supercomputers having distributed memory. Our computational algorithm is based on the popular TreeSPH code of Hernquist & Katz (1989)[ApJS, 70, 419]. PTreeSPH utilizes a domain decomposition procedure and a synchronous hypercube communication paradigm to build self-contained subvolumes of the simulation on each processor at every timestep. Computations then proceed in a manner analogous to a serial code. We use the Message Passing Interface (MPI) communications package, making our code easily portable to a variety of parallel systems. PTreeSPH uses individual smoothing lengths and timesteps, with a communication algorithm designed to minimize exchange of information while still providing all information required to accurately perform SPH computations. We have incorporated periodic boundary conditions with forces calculated using a quadrupole Ewald summation method, and comoving integration under a variety of cosmologies. Following algorithms presented in Katz et al. (1996)[ApJS, 105, 19], we have also included radiative cooling, heating from a parameterized ionizing background, and star formation. A cosmological simulation from z = 49 to z = 2 with 64 3 gas particles and 64 3 dark matter particles requires ˜ 1800 node-hours on a Cray T3D, with a communications overhead of ˜ 8%, load balanced to ? 95% level. When used on the new Cray T3E, this code will be capable of performing cosmological hydrodynamical simulations down to z = 0 with ˜ 2 × 10 6 particles, or to z = 2 with ˜ 10 7 particles, in a reasonable amount of time. Even larger simulations will be practical in situations where the matter is not highly clustered or when periodic boundaries are not required.

  2. Short Tree, Long Tree, Right Tree, Wrong Tree: New Acquisition Bias Corrections for Inferring SNP Phylogenies

    PubMed Central

    Leaché, Adam D.; Banbury, Barbara L.; Felsenstein, Joseph; de Oca, Adrián nieto-Montes; Stamatakis, Alexandros

    2015-01-01

    Single nucleotide polymorphisms (SNPs) are useful markers for phylogenetic studies owing in part to their ubiquity throughout the genome and ease of collection. Restriction site associated DNA sequencing (RADseq) methods are becoming increasingly popular for SNP data collection, but an assessment of the best practises for using these data in phylogenetics is lacking. We use computer simulations, and new double digest RADseq (ddRADseq) data for the lizard family Phrynosomatidae, to investigate the accuracy of RAD loci for phylogenetic inference. We compare the two primary ways RAD loci are used during phylogenetic analysis, including the analysis of full sequences (i.e., SNPs together with invariant sites), or the analysis of SNPs on their own after excluding invariant sites. We find that using full sequences rather than just SNPs is preferable from the perspectives of branch length and topological accuracy, but not of computational time. We introduce two new acquisition bias corrections for dealing with alignments composed exclusively of SNPs, a conditional likelihood method and a reconstituted DNA approach. The conditional likelihood method conditions on the presence of variable characters only (the number of invariant sites that are unsampled but known to exist is not considered), while the reconstituted DNA approach requires the user to specify the exact number of unsampled invariant sites prior to the analysis. Under simulation, branch length biases increase with the amount of missing data for both acquisition bias correction methods, but branch length accuracy is much improved in the reconstituted DNA approach compared to the conditional likelihood approach. Phylogenetic analyses of the empirical data using concatenation or a coalescent-based species tree approach provide strong support for many of the accepted relationships among phrynosomatid lizards, suggesting that RAD loci contain useful phylogenetic signal across a range of divergence times despite the presence of missing data. Phylogenetic analysis of RAD loci requires careful attention to model assumptions, especially if downstream analyses depend on branch lengths. PMID:26227865

  3. A Model In Which There Are Jech Kunen Trees But There Are No Kurepa Trees 1

    E-print Network

    Jin, Renling

    A Model In Which There Are Jech Kunen Trees But There Are No Kurepa Trees 1 Saharon Shelah2 and Renling Jin Abstract By an !1 tree we mean a tree of power !1 and height !1. We call an !1 tree a Jech Kunen tree if it has many branches for some strictly between !1 and 2!1 . In this paper we construct

  4. Mapping tree density at a global scale.

    PubMed

    Crowther, T W; Glick, H B; Covey, K R; Bettigole, C; Maynard, D S; Thomas, S M; Smith, J R; Hintler, G; Duguid, M C; Amatulli, G; Tuanmu, M-N; Jetz, W; Salas, C; Stam, C; Piotto, D; Tavani, R; Green, S; Bruce, G; Williams, S J; Wiser, S K; Huber, M O; Hengeveld, G M; Nabuurs, G-J; Tikhonova, E; Borchardt, P; Li, C-F; Powrie, L W; Fischer, M; Hemp, A; Homeier, J; Cho, P; Vibrans, A C; Umunay, P M; Piao, S L; Rowe, C W; Ashton, M S; Crane, P R; Bradford, M A

    2015-09-10

    The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization. PMID:26331545

  5. Mapping tree density at a global scale

    NASA Astrophysics Data System (ADS)

    Crowther, T. W.; Glick, H. B.; Covey, K. R.; Bettigole, C.; Maynard, D. S.; Thomas, S. M.; Smith, J. R.; Hintler, G.; Duguid, M. C.; Amatulli, G.; Tuanmu, M.-N.; Jetz, W.; Salas, C.; Stam, C.; Piotto, D.; Tavani, R.; Green, S.; Bruce, G.; Williams, S. J.; Wiser, S. K.; Huber, M. O.; Hengeveld, G. M.; Nabuurs, G.-J.; Tikhonova, E.; Borchardt, P.; Li, C.-F.; Powrie, L. W.; Fischer, M.; Hemp, A.; Homeier, J.; Cho, P.; Vibrans, A. C.; Umunay, P. M.; Piao, S. L.; Rowe, C. W.; Ashton, M. S.; Crane, P. R.; Bradford, M. A.

    2015-09-01

    The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.

  6. Coalescent Histories for Lodgepole Species Trees.

    PubMed

    Disanto, Filippo; Rosenberg, Noah A

    2015-10-01

    Coalescent histories are combinatorial structures that describe for a given gene tree and species tree the possible lists of branches of the species tree on which the gene tree coalescences take place. Properties of the number of coalescent histories for gene trees and species trees affect a variety of probabilistic calculations in mathematical phylogenetics. Exact and asymptotic evaluations of the number of coalescent histories, however, are known only in a limited number of cases. Here we introduce a particular family of species trees, the lodgepole species trees (?n)n ? 0, in which tree ?n has m = 2n+1 taxa. We determine the number of coalescent histories for the lodgepole species trees, in the case that the gene tree matches the species tree, showing that this number grows with m!! in the number of taxa m. This computation demonstrates the existence of tree families in which the growth in the number of coalescent histories is faster than exponential. Further, it provides a substantial improvement on the lower bound for the ratio of the largest number of matching coalescent histories to the smallest number of matching coalescent histories for trees with m taxa, increasing a previous bound of [Formula: see text] to [Formula: see text]. We discuss the implications of our enumerative results for phylogenetic computations. PMID:25973633

  7. New program controls tree management

    SciTech Connect

    Beaty, W.

    1995-02-01

    Senior management of TransAlta Utilities Corp. (TAU) Calgary, Alberta, Canada, was highly dissatisfied with the fact that even though the distribution line clearance budget had been increased an average 35 percent a year between 1978 and 1984, there were few if any discernible positive results. Tree-related power outages kept increasing and budget requests from the field kept increasing. In searching for a solution TAU had to deal with the concept that the right level of funding can only be determined through an inventory of tree work. This inventory is comprised of two factors, the number of trees in proximity to the power lines and the local growth rates. Based on the inventory of a hired consultant, a 12-year budget projection was established. The period covered entailed a six-year, first-cycle or catch up phase, and a six-year, second-cycle maintenance phase. In implementing the new vegetation management program in 1986, TAU decided to contact each landowner directly to obtain consent to undertake the tree work. The intent was to reduce the risk of claims while maximizing tree removals. Complaints and claims were dramatically reduced and currently run at about one per 1,000 landowners and budgets have dropped back to the 1985 levels as predicted for the maintenance phase.

  8. TREE TRAILS Trees are living organisms with many specialized structures leaves, roots, wood, and the living cells

    E-print Network

    1 TREE TRAILS Trees are living organisms with many specialized structures ­ leaves, roots, wood, and the living cells that connect them. Understanding how trees are constructed and grow is essential to care for trees and calculate the benefits that trees provide. Tree Trails Tree Structure and Function Goal

  9. Measurement of tree canopy architecture

    NASA Technical Reports Server (NTRS)

    Martens, S. N.; Ustin, S. L.; Norman, J. M.

    1991-01-01

    The lack of accurate extensive geometric data on tree canopies has retarded development and validation of radiative transfer models. A stratified sampling method was devised to measure the three-dimensional geometry of 16 walnut trees which had received irrigation treatments of either 100 or 33 per cent of evapotranspirational (ET) demand for the previous two years. Graphic reconstructions of the three-dimensional geometry were verified by 58 independent measurements. The distributions of stem- and leaf-size classes, lengths, and angle classes were determined and used to calculate leaf area index (LAI), stem area, and biomass. Reduced irrigation trees have lower biomass of stems, leaves and fruit, lower LAI, steeper leaf angles and altered biomass allocation to large stems. These data can be used in ecological models that link canopy processes with remotely sensed measurements.

  10. Attention trees and semantic paths

    NASA Astrophysics Data System (ADS)

    Giusti, Christian; Pieroni, Goffredo G.; Pieroni, Laura

    2007-02-01

    In the last few decades several techniques for image content extraction, often based on segmentation, have been proposed. It has been suggested that under the assumption of very general image content, segmentation becomes unstable and classification becomes unreliable. According to recent psychological theories, certain image regions attract the attention of human observers more than others and, generally, the image main meaning appears concentrated in those regions. Initially, regions attracting our attention are perceived as a whole and hypotheses on their content are formulated; successively the components of those regions are carefully analyzed and a more precise interpretation is reached. It is interesting to observe that an image decomposition process performed according to these psychological visual attention theories might present advantages with respect to a traditional segmentation approach. In this paper we propose an automatic procedure generating image decomposition based on the detection of visual attention regions. A new clustering algorithm taking advantage of the Delaunay- Voronoi diagrams for achieving the decomposition target is proposed. By applying that algorithm recursively, starting from the whole image, a transformation of the image into a tree of related meaningful regions is obtained (Attention Tree). Successively, a semantic interpretation of the leaf nodes is carried out by using a structure of Neural Networks (Neural Tree) assisted by a knowledge base (Ontology Net). Starting from leaf nodes, paths toward the root node across the Attention Tree are attempted. The task of the path consists in relating the semantics of each child-parent node pair and, consequently, in merging the corresponding image regions. The relationship detected in this way between two tree nodes generates, as a result, the extension of the interpreted image area through each step of the path. The construction of several Attention Trees has been performed and partial results will be shown.

  11. Transport of Methane in Trees

    NASA Astrophysics Data System (ADS)

    Kutschera, E.; Khalil, A. K.; Shearer, M. J.; Rosenstiel, T.; Rice, A. L.

    2011-12-01

    Although overall methane (CH4) emissions for croplands, wetlands, and forests have been measured, the exact dynamics of CH4 transport through trees is not well understood. What roles transport mechanisms play in emission rates has been thoroughly investigated for rice, but is fairly unknown for trees. Better defined plant transport mechanisms yield more accurate determination of greenhouse gas flux and its variations, contributing to a comprehensive theory quantifying greenhouse gas emissions globally. CH4 emissions from the common wetland tree species black cottonwood (Populus trichocarpa) native to the Pacific Northwest have been measured under hydroponic conditions in order to separate plant transport processes from the influence of soil processes. Canopy emissions of CH4 have been measured via canopy enclosure. Measurements of CH4 flux from each of 16 trees have indicated that emissions are normally constant over the half-hour sampling period. Samples for stable carbon isotope composition have been taken during these experiments and measured on a mass spectrometer. Compared to the isotopic composition of root water CH4, canopy CH4 is depleted in 13C; this indicates that CH4 moving through the tree is not following a bulk flow pathway (where no depletion would occur), but instead moves either diffusively or through other cell or tissue barriers. No correlation was found to exist between leaf area and CH4 emission; this is vital to upscaling tree-level emissions to the global scale since leaf area index (LAI) cannot be treated as an appropriate parameter to upscale flux. Correctly informing global-scale CH4 fluxes from plants requires an association between the role plant physiology plays in the production and transport of CH4 and magnitudes of flux. This research was supported by the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG02-08ER64515. Supported in part through NASA / Oregon Space Grant Consortium, grant NNG05GJ85H.

  12. Peanut and tree nut allergy.

    PubMed

    Cox, Amanda; Sicherer, Scott H

    2015-01-01

    Allergy to peanut and tree nuts is a major worldwide health concern. The prevalence of these allergies may be increasing, but the reasons for these increases remain unclear. This group of foods accounts for a large proportion of severe and fatal food-allergic reactions. These allergies present most often during childhood but can occur at any age. Resolution is possible but uncommon, and frequent lifetime reactions caused by accidental ingestion are a serious problem. The major allergens of peanut and most tree nuts have been identified, allowing for insights into patient diagnoses, clinical outcomes, and potential future immunotherapies. PMID:26022873

  13. Tree Height Calculator: An Android App for Estimating Tree Height

    NASA Astrophysics Data System (ADS)

    Burca, V. S.; Htet, N. M.; Huang, X.; de Lanerolle, T. R.; Morelli, R.; Gourley, J. R.

    2011-12-01

    Conventionally, measuring tree height requires a collection of different tools - clinometer, transit, pencil, paper, laptop computer. Results are recorded manually and entered into a spreadsheet or database for future calculation and analysis. Tree Height Calculator is a mobile Android app the integrates the various steps in this process thereby improving the accuracy and dramatically reducing the time required to go from taking measurements to analyzing data. Given the user's height and the distance from the base of the tree (which can be downloaded into the app from a server), the app uses the phone's orientation sensor to calculate the angle of elevation. A simple trigonometric formula is then used to calculate and record the tree's height in the phone's database. When the phone has a WiFi connection, the data are transmitted to a server, from where they can be downloaded directly into a spreadsheet. The application was first tested in an Environmental Science laboratory at Trinity College. On the first trial, 103 data samples were collected, stored, and uploaded to the online database with only couple of dropped data points. On the second trial, 98 data samples were gathered with no loss of data. The app combined the individual measurements taken by the students in the lab, reducing the time required to produce a graph of the class's results from days to hours.

  14. SSSSave theave theave theave the TreesTreesTreesTrees!!!! Tree:Tree:Tree:Tree: Hackberry, Celtis Occidentalis L.Hackberry, Celtis Occidentalis L.Hackberry, Celtis Occidentalis L.Hackberry, Celtis Occidentalis L.

    E-print Network

    Ashline, George

    that bloom in May has leaves that turn from green to yellow in the fallhas leaves that turn from green to yellow in the fallhas leaves that turn from green to yellow in the fallhas leaves that turn from greenThe Lorax to youto youto youto you Then together we are going to think about what we use trees for and what

  15. Water Transport in Trees--An Artificial Laboratory Tree

    ERIC Educational Resources Information Center

    Susman, K.; Razpet, N.; Cepic, M.

    2011-01-01

    Water transport in tall trees is an everyday phenomenon, seldom noticed and not completely understood even by scientists. As a topic of current research in plant physiology it has several advantages for presentation within school physics lectures: it is interdisciplinary and clearly shows the connection between physics and biology; the…

  16. AncesTrees: ancestry estimation with randomized decision trees.

    PubMed

    Navega, David; Coelho, Catarina; Vicente, Ricardo; Ferreira, Maria Teresa; Wasterlain, Sofia; Cunha, Eugénia

    2015-09-01

    In forensic anthropology, ancestry estimation is essential in establishing the individual biological profile. The aim of this study is to present a new program--AncesTrees--developed for assessing ancestry based on metric analysis. AncesTrees relies on a machine learning ensemble algorithm, random forest, to classify the human skull. In the ensemble learning paradigm, several models are generated and co-jointly used to arrive at the final decision. The random forest algorithm creates ensembles of decision trees classifiers, a non-linear and non-parametric classification technique. The database used in AncesTrees is composed by 23 craniometric variables from 1,734 individuals, representative of six major ancestral groups and selected from the Howells' craniometric series. The program was tested in 128 adult crania from the following collections: the African slaves' skeletal collection of Valle da Gafaria; the Medical School Skull Collection and the Identified Skeletal Collection of 21st Century, both curated at the University of Coimbra. The first step of the test analysis was to perform ancestry estimation including all the ancestral groups of the database. The second stage of our test analysis was to conduct ancestry estimation including only the European and the African ancestral groups. In the first test analysis, 75% of the individuals of African ancestry and 79.2% of the individuals of European ancestry were correctly identified. The model involving only African and European ancestral groups had a better performance: 93.8% of all individuals were correctly classified. The obtained results show that AncesTrees can be a valuable tool in forensic anthropology. PMID:25053239

  17. Bayesian Detection in Bounded Height Tree Networks

    E-print Network

    Tay, Wee Peng

    We study the detection performance of large scale sensor networks, configured as trees with bounded height, in which information is progressively compressed as it moves towards the root of the tree. We show that, under a ...

  18. Bayesian Evidence Framework for Decision Tree Learning

    NASA Astrophysics Data System (ADS)

    Chatpatanasiri, Ratthachat; Kijsirikul, Boonserm

    2005-11-01

    This work is primary interested in the problem of, given the observed data, selecting a single decision (or classification) tree. Although a single decision tree has a high risk to be overfitted, the induced tree is easily interpreted. Researchers have invented various methods such as tree pruning or tree averaging for preventing the induced tree from overfitting (and from underfitting) the data. In this paper, instead of using those conventional approaches, we apply the Bayesian evidence framework of Gull, Skilling and Mackay to a process of selecting a decision tree. We derive a formal function to measure `the fitness' for each decision tree given a set of observed data. Our method, in fact, is analogous to a well-known Bayesian model selection method for interpolating noisy continuous-value data. As in regression problems, given reasonable assumptions, this derived score function automatically quantifies the principle of Ockham's razor, and hence reasonably deals with the issue of underfitting-overfitting tradeoff.

  19. Dealing with Storm-Damaged Trees 

    E-print Network

    Kirk, Melanie; Taylor, Eric; Foster, C. Darwin

    2005-10-25

    -Damaged Trees Melanie R. Kirk, Extension Program Specialist, Eric L. Taylor, Assistant Professor and Extension Specialist, and C. Darwin Foster, Associate Department Head and Extension Program Leader for Forestry, The Texas A&M University System Downed trees...

  20. The Shapley value of phylogenetic trees.

    PubMed

    Haake, Claus-Jochen; Kashiwada, Akemi; Su, Francis Edward

    2008-04-01

    Every weighted tree corresponds naturally to a cooperative game that we call a tree game; it assigns to each subset of leaves the sum of the weights of the minimal subtree spanned by those leaves. In the context of phylogenetic trees, the leaves are species and this assignment captures the diversity present in the coalition of species considered. We consider the Shapley value of tree games and suggest a biological interpretation. We determine the linear transformation M that shows the dependence of the Shapley value on the edge weights of the tree, and we also compute a null space basis of M. Both depend on the split counts of the tree. Finally, we characterize the Shapley value on tree games by four axioms, a counterpart to Shapley's original theorem on the larger class of cooperative games. We also include a brief discussion of the core of tree games. PMID:17805545

  1. Can These Trees Be Saved? (Spanish) 

    E-print Network

    Taylor, Eric; Foster, C. Darwin

    2007-10-08

    This publication explains how to determine whether a storm-damaged tree can be saved. If the damage is not severe, most trees will recover in time. Helpful illustrations depict different levels of damage....

  2. SEVEN TREES IN ONE Andreas Blass

    E-print Network

    Blass, Andreas R.

    elementary constructions can be extracted from ex­ istence proofs carried out in the much more liberal a depth to the empty tree, we assign 0.) As this terminology suggests, we visualize trees as growing

  3. Electric Trees and Pond Creatures.

    ERIC Educational Resources Information Center

    Weaver, Helen; Hounshell, Paul B.

    1978-01-01

    Two learning activities are presented to develop observation and classification skills at the elementary level. The first is an electric box that associates tree names with leaf and bark specimens, and the second is a pond water observation and slide preparation activity. (BB)

  4. Support Vector Machine Classification Trees.

    PubMed

    de Boves Harrington, Peter

    2015-11-01

    Proteomic and metabolomic studies based on chemical profiling require powerful classifiers to model accurately complex collections of data. Support vector machines (SVMs) are advantageous in that they provide a maximum margin of separation for the classification hyperplane. A new method for constructing classification trees, for which the branches comprise SVMs, has been devised. The novel feature is that the distribution of the data objects is used to determine the SVM encoding. The variance and covariance of the data objects are used for determining the bipolar encoding required for the SVM. The SVM that yields the lowest entropy of classification becomes the branch of the tree. The SVM-tree classifier has the added advantage that nonlinearly separable data may be accurately classified without optimization of the cost parameter C or searching for a correct higher dimensional kernel transform. It compares favorably to a regularized linear discriminant analysis, SVMs in a one against all multiple classifier, and a fuzzy rule-building expert system, a tree classifier with a fuzzy margin of separation. SVMs offer a speed advantage, especially for data sets that have more measurements than objects. PMID:26461495

  5. Logistic Model Trees Niels Landwehr

    E-print Network

    Frank, Eibe

    Logistic Model Trees Niels Landwehr Institute for Computer Science, University of Freiburg for classification problems, using logistic regression instead of linear regression. We use a stagewise fitting process to construct the logistic regression models that can select relevant attributes in the data

  6. Logistic Model Trees + Niels Landwehr

    E-print Network

    Frank, Eibe

    Logistic Model Trees + Niels Landwehr Institute for Computer Science, University of Freiburg for classification problems, using logistic regression instead of linear regression. We use a stagewise fitting process to construct the logistic regression models that can select relevant attributes in the data

  7. The Tree of Life Project

    ERIC Educational Resources Information Center

    Milbrath, Sherry

    2009-01-01

    Middle-school students are just beginning to recognize their place in the world. That is why this author believes it is important to incorporate their world into their art. In this article, the author discusses the "Tree of Life" project, which she developed for her students in order to make them aware of various environmental issues, and how to…

  8. Human Arterial-Tree Multiscale

    E-print Network

    Human Arterial- Tree Multiscale Simulations CRUNCH Group Division of Applied Mathematics Brown University George Karniadakis and Leopold Grinberg #12;For modeling purposes, we subdivide the arterial system into three levels: 1. The Macrovascular Network (MaN), which includes large arteries, down

  9. Not Just a Fall Tree

    ERIC Educational Resources Information Center

    Miller-Hewes, Kathy A.

    2004-01-01

    Trees burst with color in the northern states. Autumn leaves dust the ground. Painting the fall landscape is nothing new. Teachers have been doing it in classrooms for decades. The approach, however, can make the difference between whether the fall landscape is simply painting for fun, or a real learning experience. Students learn best when they…

  10. GumTree: Data reduction

    NASA Astrophysics Data System (ADS)

    Rayner, Hugh; Hathaway, Paul; Hauser, Nick; Fei, Yang; Franceschini, Ferdi; Lam, Tony

    2006-11-01

    Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation.

  11. MYCOTOXINS IN EDIBLE TREE NUTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tree nuts (almonds, pistachios, and walnuts) are an exceptionally valuable crop, especially in California, with an aggregate value approaching $3.5 billion. Much of this economic value comes from overseas markets, with up to 60% of the crop being exported. The product can be contaminated with aflat...

  12. Millersville University's Trees of Distinction

    E-print Network

    Hardy, Christopher R.

    sycamore (Platanus acerifolia) 2014-05-22 #12;#16: Black walnut (Juglans nigra) 2014-05-22 #12;#17: Persian walnut (Juglans regia) 2014-05-22 #12;#18: Female Ginkgo, Maidenhair tree (Ginkgo biloba) 2014-06-14 #12

  13. Compartmentalization of Decay in Trees.

    ERIC Educational Resources Information Center

    Shigo, Alex L.

    1985-01-01

    Unlike animals, which heal, trees compartmentalize by setting boundaries that resist the spread of invading microorganisms. Discusses the creation of new walls by anatomical and chemical means in response to death of a branch or pruning. Points out that genetic control of compartmentalization has resulted from evolution of resistant species. (DH)

  14. The Education of Little Tree.

    ERIC Educational Resources Information Center

    Carter, Forrest

    First published in 1976, this autobiography contains Forrest Carter's--Little Tree's--remembrances of life with his Eastern Cherokee Hill country grandparents in the 1930s. There are 21 chapters, recounting humorous and serious episodes from a 5-year period and dealing with the themes of growing up, Indian life and values, family relationships,…

  15. Feathered Hollow in Living Tree

    USGS Multimedia Gallery

    Hollow in living tree in gallery forest of tributary to Tebicuary river. Grey feathers stuck along bottom of entrance suggest that it may be used by a bird. Paraguay is home to at least 589 breeding bird species and 120 migratory bird species. The Ñeembucú Region is typified by extensi...

  16. Cedar Tree in Bryce Canyon

    USGS Multimedia Gallery

    A cedar tree in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sandstone that forms their ba...

  17. Can Children Read Evolutionary Trees?

    ERIC Educational Resources Information Center

    Ainsworth, Shaaron; Saffer, Jessica

    2013-01-01

    Representations of the "tree of life" such as cladograms show the history of lineages and their relationships. They are increasingly found in formal and informal learning settings. Unfortunately, there is evidence that these representations can be challenging to interpret correctly. This study explored the question of whether children aged 7-11…

  18. Trees of Our National Forests.

    ERIC Educational Resources Information Center

    Forest Service (USDA), Washington, DC.

    Presented is a description of the creation of the National Forests system, how trees grow, managing the National Forests, types of management systems, and managing for multiple use, including wildlife, water, recreation and other uses. Included are: (1) photographs; (2) line drawings of typical leaves, cones, flowers, and seeds; and (3)…

  19. The Trees that surround us

    NASA Astrophysics Data System (ADS)

    Costa, M. E. G.; Rodrigues, M. A. S.

    2012-04-01

    In our school the activities linked with sciences are developed in a partnership with other school subjects. Interdisciplinary projects are always valued from beginning to end of a project. It is common for teachers of different areas to work together in a Science project. Research of English written articles is very important not only for the development of our students' scientific literacy but also as a way of widening knowledge and a view on different perspectives of life instead of being limited to research of any articles in Portuguese language. In this study we are going to collect data about the predominant tree species in the region, especially the invasive trees from the acacia species, the native tree species and the commercial species. We are going to study the reasons for the appearance of each species and draw a chart of soil occupation in the council. This chart will also allow the study of the distribution and use of land for each tree species. This research work is the first stage for a contribution to warn the town council of the dangers of the invasive species to the future economy of the council.

  20. The Gift of the Tree

    ERIC Educational Resources Information Center

    Jones, Marla Wagner

    2009-01-01

    A piece of children's literature can be a powerful tool for teaching and learning science; however, it takes more than reading about a topic to qualify as "doing science." Inspired by the book, "The Gift of the Tree", the author developed an in-depth interdisciplinary lesson for her sixth-grade students without diluting the science. Through this…

  1. The Tree of Animal Life

    ERIC Educational Resources Information Center

    Braude, Stan

    2007-01-01

    In this article, the author describes a short activity which introduces third- to fifth-grade students to animal classification. The Tree of Animal Life activity is a simple, sorting exercise that can help them see a bigger picture. The activity sets the stage for learning about animal taxonomy and introduces the characteristics of various animal…

  2. Key for Trees of Iowa.

    ERIC Educational Resources Information Center

    Coder, Kim D.; Wray, Paul H.

    This key is designed to help identify the most common trees found in Iowa. It is based on vegetative characteristics such as leaves, fruits, and bark and is illustrated with black and white line drawings. Since vegetative characteristics vary due to climate, age, soil fertility, and other conditions, the numerical sizes listed, such as length and…

  3. Organic Fruit Tree Rick Foster

    E-print Network

    Pittendrigh, Barry

    of fruit · Sprays of sulfur provided some control · Sooty blotch and fly speck can be washed off #12;Apple fruit formation, regular sprays of sulfur every 10-14 days · Expect some culls #12;Insects and MitesOrganic Fruit Tree Production Rick Foster Department of Entomology Purdue University #12;Challenges

  4. Chopping Down the Cherry Tree.

    ERIC Educational Resources Information Center

    Griswold, Jerry

    1995-01-01

    Attempts once again to put to rest the infamous "I cannot tell a lie" episode involving George Washington and a downed cherry tree. Appends an editor's note that states that William Bennett's "The Children's Book of Virtues" which perpetuates this infamous piece of "fakelore." (RS)

  5. Decision-tree construction and analysis

    SciTech Connect

    Murphy, P.; Olson, B.H.

    1996-02-01

    Decision-tree construction and analysis indicate the quantitative occurrence of sulfate-reducing bacteria in a groundwater basin. The decision-tree analysis allowed determination of the most important measured variables (discriminators) associated with the occurrence of sulfate-reducing bacteria. Those variables may be used to improve reliability and validity of the tree. Statistical validation of endpoint data (leaves) is described, and decision trees are presented that increase the understanding of individual wells and hypothesize causes for sulfate-reducing bacteria.

  6. Collective Tree Spanners in Graphs with Bounded Genus, Chordality, Tree-Width,

    E-print Network

    Dragan, Feodor F.

    Collective Tree Spanners in Graphs with Bounded Genus, Chordality, Tree-Width, or Clique {dragan, cyan}@cs.kent.edu Abstract. In this paper we study collective additive tree spanners for special) admits a system of µ collective additive tree r-spanners if there is a system T (G) of at most µ spanning

  7. Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full Coalescent Analysis

    E-print Network

    Rosenberg, Noah

    Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full framework for estimating species trees and species demograph- ics from genetic markers. However, practical trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes

  8. Monitoring amenity tree health in England The Condition Survey of Non-woodland Amenity Trees

    E-print Network

    36 Monitoring amenity tree health in England The Condition Survey of Non-woodland Amenity Trees)-led survey which enables us to monitor the condition of amenity trees in parks, city streets and stately countries since 1987 (Hendry, 2005). Whilst the Forest Condition Survey concentrates on forest trees

  9. RELATING TREE PHYSIOLOGY TO PAST AND FUTURE CHANGES IN TROPICAL RAINFOREST TREE COMMUNITIES

    E-print Network

    Coley, Phyllis

    RELATING TREE PHYSIOLOGY TO PAST AND FUTURE CHANGES IN TROPICAL RAINFOREST TREE COMMUNITIES THOMAS. Predicting future changes in tropical rainforest tree communities requires a good under- standing of past to which tropical rainforest tree communities have changed during the last few thousand years has been

  10. DECISION TREE INDUCTION FOR DYNAMIC, HIGH-DIMENSIONAL DATA USING P-TREES1

    E-print Network

    Denton, Anne M.

    DECISION TREE INDUCTION FOR DYNAMIC, HIGH-DIMENSIONAL DATA USING P-TREES1 Anne Denton and William.Denton, William.Perrizo}@ndsu.nodak.edu Abstract1 Decision Tree Induction is a powerful classification tool be relevant. Decision tree branches are evaluated as needed, based on the most recent data, focusing entirely

  11. Totally Tree-mendous Activities: Projects To Discover the Beauty and Benefits of Trees.

    ERIC Educational Resources Information Center

    Hollister, Sarah

    This teacher's guide supplies information and hands-on activities to teach about trees from several disciplines. Activities are grouped into six areas that cover botany, social studies, arts and literature (aesthetics), and trees as a resource. Sections include: (1) Tree Identification, which defines trees and leaves and presents activities that…

  12. Discordance of Species Trees with Their Most Likely Gene Trees: A Unifying Principle

    E-print Network

    Rosenberg, Noah

    Letter Discordance of Species Trees with Their Most Likely Gene Trees: A Unifying Principle Noah A@stanford.edu. Associate editor: Barbara Holland Abstract A labeled gene tree topology that disagrees with a labeled species tree topology is said to be anomalous if it is more probable under a coalescent model for gene

  13. A Characterization of the Set of Species Trees that Produce Anomalous Ranked Gene Trees

    E-print Network

    Rosenberg, Noah

    A Characterization of the Set of Species Trees that Produce Anomalous Ranked Gene Trees James H. Degnan, Noah A. Rosenberg, and Tanja Stadler Abstract--Ranked gene trees, which consider both the gene tree topology and the sequence in which gene lineages separate, can potentially provide a new source

  14. RESOVING THE GENE TREE AND SPECIES TREE PROBLEM BY PHYLOGENETIC MINING

    E-print Network

    Wong, Limsoon

    RESOVING THE GENE TREE AND SPECIES TREE PROBLEM BY PHYLOGENETIC MINING XIAOXU HAN Department of Mathematics and Bioinformatics Program, Eastern Michigan University Ypsilanti, MI 48197, USA The gene tree and species tree problem remains a central problem in phylogenomics. To overcome this problem, gene

  15. Kinetic Medians and -Trees Pankaj K. Agarwal

    E-print Network

    Agarwal, Pankaj K.

    Kinetic Medians and -Trees Pankaj K. Agarwal½ , Jie Gao¾ , and Leonidas J. Guibas¾ ½ Department move, we use event-based kinetic data structures to update the tree when necessary. Both trees undergo on the query time [26,25, 19] or are too complicated [1, 15]. In this paper we develop kinetic data structures

  16. Compound WordsCompound WordsCompound WordsCompound Words Crabapple TreeCrabapple TreeCrabapple TreeCrabapple Tree

    E-print Network

    Ashline, George

    J.C. 2004 Compound WordsCompound WordsCompound WordsCompound Words Crabapple TreeCrabapple Tree the mixture of two or more different things. Therefore, a compound word is the combination of two different words to form a new word. An example of such a word is "crabapple." Go to the crabapple tree. Observe

  17. Street Tree Inventory Report and Recommendations

    E-print Network

    and planting. * Conduct an annual Arbor Day celebration and involve local groups. * Craft a public tree care ...................................................................6 Street Tree Care Condition ...........................................................7 than 24" diameter. * Two-thirds of street trees are in good condition and 59% require only routine care

  18. University of Oregon Atlas of Trees

    E-print Network

    Cina, Jeff

    University of Oregon Atlas of Trees Maps created by the UO InfoGraphics Lab, Department of Geography #12;University of Oregon Atlas of Trees Web Version ­ July 2012 The printed version of the Atlas of Trees was first produced in 1996

  19. Random trees Jean-Franois Le Gall

    E-print Network

    Le Gall, Jean-François

    Random trees Jean-François Le Gall Université Paris-Sud Orsay and Institut universitaire de France IMS Annual Meeting, Göteborg, August 2010 Jean-François Le Gall (Université Paris-Sud) Random trees Göteborg 1 / 40 #12;Outline Trees are mathematical objects that play an important role in several areas

  20. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions §...

  1. Remarks about Hardy inequalities on metric trees

    E-print Network

    Tomas Ekholm; Rupert L. Frank; Hynek Kovarik

    2007-11-13

    We find sharp conditions on the growth of a rooted regular metric tree such that the Neumann Laplacian on the tree satisfies a Hardy inequality. In particular, we consider homogeneous metric trees. Moreover, we show that a non-trivial Aharonov-Bohm magnetic field leads to a Hardy inequality on a loop graph.

  2. "These trees were presented to ONRC by

    E-print Network

    Brown, Sally

    "These trees were presented to ONRC by Fred Rosmond who propagated them from acorns he collected. Oregon White Oak is the only native oak of Washington. As these trees grow we will be reminded of Fred." These words are etched upon a modest bronze plate which stands before the two thriving Oregon White Oak trees

  3. Forest Research Much more than trees

    E-print Network

    Forest Research Much more than trees #12;Welcome to Forest Research. We are the research agency much more than trees ­ it's about adapting to, and mitigating the risks from, climate change and land-use management, whose work focuses on the use of applied science for tree, woodland and forest

  4. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions §...

  5. 7 CFR 1214.3 - Christmas tree.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Christmas tree. 1214.3 Section 1214.3 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions §...

  6. Simplifying gene trees for easier comprehension

    PubMed Central

    Lott, Paul-Ludwig; Mundry, Marvin; Sassenberg, Christoph; Lorkowski, Stefan; Fuellen, Georg

    2006-01-01

    Background In the genomic age, gene trees may contain large amounts of data making them hard to read and understand. Therefore, an automated simplification is important. Results We present a simplification tool for gene trees called TreeSimplifier. Based on species tree information and HUGO gene names, it summarizes "monophyla". These monophyla correspond to subtrees of the gene tree where the evolution of a gene follows species phylogeny, and they are simplified to single leaves in the gene tree. Such a simplification may fail, for example, due to genes in the gene tree that are misplaced. In this way, misplaced genes can be identified. Optionally, our tool glosses over a limited degree of "paraphyly" in a further simplification step. In both simplification steps, species can be summarized into groups and treated as equivalent. In the present study we used our tool to derive a simplified tree of 397 leaves from a tree of 1138 leaves. Comparing the simplified tree to a "cartoon tree" created manually, we note that both agree to a high degree. Conclusion Our automatic simplification tool for gene trees is fast, accurate, and effective. It yields results of similar quality as manual simplification. It should be valuable in phylogenetic studies of large protein families. The software is available at . PMID:16643669

  7. MITCHEL RESNICK THINKING LIKE A TREE

    E-print Network

    Resnick, Mitchel

    ." It is a strange looking tree. At the base of the tree is a tangle of roots, rising about a meter above the ground in the biological world, used not only by walking trees but many other plants and animals as well. Ecological

  8. Linear Machine Decision Trees Paul E. Utgoff

    E-print Network

    Utgoff, Paul

    Linear Machine Decision Trees Paul E. Utgoff Carla E. Brodley Department of Computer Science Abstract This article presents an algorithm for inducing multiclass decision trees with multivariate tests a classifier in the form of a decision tree, using a combination of methods from connectionist and decision

  9. Decision Trees for Functional Variables Suhrid Balakrishnan

    E-print Network

    Decision Trees for Functional Variables Suhrid Balakrishnan Department of Computer Science Rutgers an intuitive scheme for ex- tending decision trees to handle functional input variables. Our results show that such decision trees are both accurate and readily interpretable. 1 INTRODUCTION We present an extension

  10. k+ DECISION TREES JAMES ASPNES 1

    E-print Network

    O'Donnell, Ryan

    k+ DECISION TREES JAMES ASPNES 1 AND ERIC BLAIS 2 AND MURAT DEMIRBAS 3 AND RYAN O'DONNELL 2 of computation for boolean functions: the 2+ decision tree. This model is an augmentation of the standard decision tree model: now each internal node queries an arbitrary set of literals and branches on whether 0

  11. Avoiding Differences Spanning Trees in Grid Graphs

    E-print Network

    Zeilberger, Doron

    Avoiding Differences Spanning Trees in Grid Graphs The Firefighter Problem Automated Proof and Discovery #12;Avoiding Differences Spanning Trees in Grid Graphs The Firefighter Problem Automated Proof and Discovery #12;Avoiding Differences Spanning Trees in Grid Graphs The Firefighter Problem Outline 1 Avoiding

  12. Street Tree Inventory Report and Recommendations

    E-print Network

    that encroach into clear zones above streets and sidewalks. * Street trees in Missouri City are valued at more than $44 million. Recommendations include: * Favor shade trees other than live oak when designing by the Texas Forest Service. It is adapted from the Street Tree Management Tool for Urban Forest Managers

  13. Big Tree of the Month -September 2013 Anne Krantz, Tree Steward and NH Big Tree Committee

    E-print Network

    New Hampshire, University of

    Sassafras (Sassafras albidum) ­ Part II We all love the colorful leaves of fall in New England. Among the brilliant leaves are the yellow to red leaves of native sassafras. Its unique mitten shaped leaves are fun. These strange leaves with unusual smooth edges make identifying sassafras easy, but it is not a common tree

  14. Tree-grass and tree-tree interactions in a temperate savanna 

    E-print Network

    Simmons, Mark Trevor

    2004-11-15

    . The maintenance and formation of savannas have been attributed to climate, soils, herbivory and fire. However, the reasons for the coexistence of trees and the grass layer have still to be determined. These two contrasting life forms create a complex of intra...

  15. RECONCILED TREES 1 Submitted to Molecular Phylogeny and Evolution

    E-print Network

    Page, Roderic

    RECONCILED TREES 1 Submitted to Molecular Phylogeny and Evolution Please address all correspondence trees From Gene to Organismal Phylogeny: Reconciled Trees and the Gene Tree/Species Tree Problem RODERIC of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K. #12;RECONCILED TREES 2

  16. Trees 1 2004 Goodrich, Tamassia Make Money Fast!

    E-print Network

    Alechina, Natasha

    Trees 1© 2004 Goodrich, Tamassia Trees Make Money Fast! Stock Fraud Ponzi Scheme Bank Robbery #12;Trees 2© 2004 Goodrich, Tamassia What is a Tree In computer science, a tree is an abstract model of a hierarchical structure A tree consists of nodes with a parent-child relation (at most one parent!) Applications

  17. The Role of Trees in Seattle's Stormwater Management

    E-print Network

    Brown, Sally

    Urban Forest Symposium May 2015 #12;Overview 1. Stormwater 2. Stormwater + Trees 3. Stormwater + Trees #12;Forest Standard #12;Urban Areas #12;Stormwater + Trees #12;Effects of Trees on Stormwater 3 depends on: · Canopy cover · Climate · Deciduous / evergreen #12;Canopy Cover Few Trees Abundant Trees

  18. Sleeping tree choice by Bwindi chimpanzees.

    PubMed

    Stanford, Craig B; O'Malley, Robert C

    2008-07-01

    Unlike nearly all other nonhuman primates, great apes build sleeping nests. In Bwindi Impenetrable National Park, Uganda, chimpanzees build nests nightly and also build day nests. We investigated patterns of nest tree use by Bwindi chimpanzees to understand ecological influences on nest tree selection. We analyzed data on 3,414 chimpanzee nests located from 2000 to 2004. Chimpanzees at Bwindi were selective in their use of nest trees. Of at least 163 tree species known to occur in Bwindi [Butynski, Ecological survey of the Impenetrable (Bwindi) Forest, Uganda, and recommendations for its conservation and management. Report to the Government of Uganda, 1984], chimpanzees utilized only 38 species for nesting. Of these, four tree species (Cassipourea sp., Chrysophyllum gorungosanum, Drypetes gerrardii, and Teclea nobilis) accounted for 72.1% of all nest trees. There was considerable variation in nesting frequencies among the top four species between and within years. However, these species were used significantly more often for nesting than other species in 70.9% (39 of 55) of the months of this study. A Spearman rank correlation found no significant relationship between tree abundance and tree species preference. Ninety-three percent of all nests were constructed in food tree species, although not necessarily at the same time the trees bore food items used by chimpanzees. The results indicate that nesting tree species preferences exist. Bwindi chimpanzees' choice of nesting tree species does not appear to be dependent on tree species density or use of the tree for food. We discuss possible reasons for the selectivity in nest trees by the Bwindi population. PMID:18381629

  19. Red-Black Trees 11/26/2007 11:09 AM Red-Black Trees 1 2004 Goodrich, Tamassia

    E-print Network

    Alechina, Natasha

    Red-Black Trees 11/26/2007 11:09 AM 1 Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison

  20. On the Hopf Algebra of Rooted Trees

    E-print Network

    Shouchuan Zhang; Jieqiong He; Peng Wang

    2007-11-20

    We find a formula to compute the number of the generators, which generate the $n$-filtered space of Hopf algebra of rooted trees, i.e. the number of equivalent classes of rooted trees with weight $n$. Applying Hopf algebra of rooted trees, we show that the analogue of Andruskiewitsch and Schneider's Conjecture is not true. The Hopf algebra of rooted trees and the enveloping algebra of the Lie algebra of rooted trees are two important examples of Hopf algebras. We give their representation and show that they have not any nonzero integrals. We structure their graded Drinfeld doubles and show that they are local quasitriangular Hopf algebras.

  1. Molecular basis of angiosperm tree architecture.

    PubMed

    Hollender, Courtney A; Dardick, Chris

    2015-04-01

    The architecture of trees greatly impacts the productivity of orchards and forestry plantations. Amassing greater knowledge on the molecular genetics that underlie tree form can benefit these industries, as well as contribute to basic knowledge of plant developmental biology. This review describes the fundamental components of branch architecture, a prominent aspect of tree structure, as well as genetic and hormonal influences inferred from studies in model plant systems and from trees with non-standard architectures. The bulk of the molecular and genetic data described here is from studies of fruit trees and poplar, as these species have been the primary subjects of investigation in this field of science. PMID:25483362

  2. Planting Kurepa Trees And Killing Jech Kunen Trees In a Model By Using One Inaccessible Cardinal 1

    E-print Network

    Jin, Renling

    Planting Kurepa Trees And Killing Jech Kunen Trees In a Model By Using One Inaccessible Cardinal 1 Saharon Shelah2 and Renling Jin Abstract By an !1 tree we mean a tree of power !1 and height !1 . Under CH and 2!1 !2 we call an !1 tree a Jech Kunen tree if it has many branches for some strictly between !1

  3. Anatomical modeling of the bronchial tree

    NASA Astrophysics Data System (ADS)

    Hentschel, Gerrit; Klinder, Tobias; Blaffert, Thomas; Bülow, Thomas; Wiemker, Rafael; Lorenz, Cristian

    2010-02-01

    The bronchial tree is of direct clinical importance in the context of respective diseases, such as chronic obstructive pulmonary disease (COPD). It furthermore constitutes a reference structure for object localization in the lungs and it finally provides access to lung tissue in, e.g., bronchoscope based procedures for diagnosis and therapy. This paper presents a comprehensive anatomical model for the bronchial tree, including statistics of position, relative and absolute orientation, length, and radius of 34 bronchial segments, going beyond previously published results. The model has been built from 16 manually annotated CT scans, covering several branching variants. The model is represented as a centerline/tree structure but can also be converted in a surface representation. Possible model applications are either to anatomically label extracted bronchial trees or to improve the tree extraction itself by identifying missing segments or sub-trees, e.g., if located beyond a bronchial stenosis. Bronchial tree labeling is achieved using a naïve Bayesian classifier based on the segment properties contained in the model in combination with tree matching. The tree matching step makes use of branching variations covered by the model. An evaluation of the model has been performed in a leaveone- out manner. In total, 87% of the branches resulting from preceding airway tree segmentation could be correctly labeled. The individualized model enables the detection of missing branches, allowing a targeted search, e.g., a local rerun of the tree-segmentation segmentation.

  4. The Dirac Operator on Regular Metric Trees

    E-print Network

    Xiao Liu

    2015-07-08

    A metric tree is a tree whose edges are viewed as line segments of positive length. The Dirac operator on such tree is the operator which operates on each edge, complemented by the matching conditions at the vertices which were given by Bolte and Harrison \\cite{BolteHarrison2003}. The spectrum of Dirac operator can be quite different, reflecting geometry of the tree. We discuss a special case of trees, namely the so-called regular trees. They possess a rich group of symmetries. This allows one to construct an orthogonal decomposition of the space $L^2(\\Gamma)$ which reduces the Dirac. Based upon this decomposition, a detailed spectral analysis of Dirac operator on the regular metric trees is possible.

  5. On finding minimum-diameter clique trees

    SciTech Connect

    Blair, J.R.S. . Dept. of Computer Science); Peyton, B.W. )

    1991-08-01

    It is well-known that any chordal graph can be represented as a clique tree (acyclic hypergraph, join tree). Since some chordal graphs have many distinct clique tree representations, it is interesting to consider which one is most desirable under various circumstances. A clique tree of minimum diameter (or height) is sometimes a natural candidate when choosing clique trees to be processed in a parallel computing environment. This paper introduces a linear time algorithm for computing a minimum-diameter clique tree. The new algorithm is an analogue of the natural greedy algorithm for rooting an ordinary tree in order to minimize its height. It has potential application in the development of parallel algorithms for both knowledge-based systems and the solution of sparse linear systems of equations. 31 refs., 7 figs.

  6. Inference of fitness from genealogical trees

    NASA Astrophysics Data System (ADS)

    Vucelja, Marija; Dayarian, Adel; Shraiman, Boris

    2013-03-01

    Natural populations are fitness diverse and can have numerous genes under selection. The genealogical trees, that one obtains by sampling, often bear hallmarks of selection, such multiple mergers, asymmetric tree branches and long terminal branches (the trees are squished towards the root). These are qualitative differences compared to trees in the absence of selection. We propose a theoretical model that links the morphology of a tree with the fitness of the leaves. We obtain multipoint correlation functions of the fitness along the tree. In this way we are able extract some quantitative information about the strength of selection from data-reconstructed trees. The extensions of this approach can potentially be useful for inferring relative fitness of sequenced genomes of tumors and for predicting viral outbreaks.

  7. Borers in New Hampshire Apple Trees Several species of insects bore into New Hampshire apple trees, including roundheaded apple tree borer,

    E-print Network

    New Hampshire, University of

    Hampshire apple trees. The adults are striking brown-and-white-striped beetles, almost an inch longBorers in New Hampshire Apple Trees Several species of insects bore into New Hampshire apple trees, including roundheaded apple tree borer, flatheaded apple-tree borer, dogwood borer (and the uncommon look

  8. Polychlorinated biphenyls in tree bark

    SciTech Connect

    Hermanson, M.H.; Hites, R.A. )

    1990-05-01

    Polychlorinated biphenyl (PCB) concentrations in tree bark vary with proximity to a source. Higher total PCB bark/air ratios in areas near contamination show that bark may retain PCB from prior periods of high atmospheric concentrations. Bark is enriched in the more chlorinated PCB homologues relative to air. Congener-specific analyses show that, when compared with air, bark favorably accumulates the less volatile congeners. Lipophilicity is not a good indicator of bark PCB concentrations, but vapor pressure is.

  9. Real Trees in the Classroom

    ERIC Educational Resources Information Center

    Fernandes, Francisca Maria; de Carvalho, Luis Mendonca; Silveira, Margarida

    2006-01-01

    At home, children often have pets that they take care of and play with; even in the classroom it is not uncommon to find a wormery, an aquarium or an ant farm. However, children rarely have the opportunity to own and care for a plant over a lengthy period of time, let alone a tree. The authors describe a project in Portugal aimed at improving…

  10. Dendrochemistry: Seeing the forest through the trees

    NASA Astrophysics Data System (ADS)

    Hauck, Danielle K.

    Dendrochemistry is a term used to describe the compositional analysis of tree-rings and its application to biomonitoring of the tree's environment. The central hypothesis of this study is that the concentrations of silver and gold in tree-rings in the Mediterranean region record the history of African dust storms. Although there have been previous studies of tree-ring composition using both NAA and other analytical techniques, to the author's knowledge, this is the first dendrochemical study to consider the effects of dust storms on tree-ring chemistry. However, the results, as with many other dendrochemical studies, are promising at best. The tree-ring concentrations in a single tree in west-central Turkey were highly correlated with the local aerosol index obtained from the Total Ozone Mapping Spectrometer (TOMS). This suggests that silver and gold concentrations in carefully selected trees may serve as a proxy indicator of dust storm activity and indirectly, the phase of the North Atlantic Oscillation. Three other trees from the same forest did not have any silver or gold concentration peaks and possible reasons for this discrepancy are discussed. The correlation with dust storms is still uncertain because it was impossible to gather appropriate information about soil characteristics or additional trees for sampling to prove or disprove the hypothesis. However, the chemistries of silver and gold are discussed to elucidate why they may be uniquely good at recording environmental signals in tree-rings. Some promising results for detecting volcanic eruptions in tree-rings were obtained on tree samples of a shorter duration (20-30 years) from Catacik Turkey that were prepared for irradiation under improved conditions of cleanliness. These tree samples were analyzed later in the project after sample preparation procedures were altered to reduce the possibility of sample contamination. Concentration peaks in the Catacik samples were correlated with the timing of the Pinatubo eruption (1991) and the El Chichon eruption in 1982. However, many of the concentration peaks were in single trees and could not be verified by comparison to other trees that grew nearby. The relative success of correlating concentration peaks in these shorter tree sequences may have been due to the improved sample preparation procedures. Another possible explanation is that concentration peaks do not remain in the tree-rings over time due to diffusion or mobilization by the tree. This would make it more difficult to find or identify possible environmental signals in the older rings of a long tree sequence. Unfortunately, this study contributes to the overwhelming number of feasibility studies that have been performed since the 1950s. There is still no consensus regarding the mechanisms responsible for recording environmental events in tree-rings beyond passive uptake. The feasibility of dendrochemistry will be more firmly established by moving forward with thoughtfully planned control studies. The refined NAA procedures developed here are necessary for future experiments which should strive to understand the actual mechanisms responsible for uptake. There are several different aspects of dendrochemistry that could be tested with control studies and that would be useful for interpreting tree-ring chemistry. For instance, dendrochemical studies could focus on the variation in specific elements between trees and the creation of composite forest chronologies for the appropriate elements. If this was successful, it would indicate that tree-ring compositions faithfully record environmental conditions in some cases and for some elements. A possible correlation was found between the Ag and Au concentration in tree-rings and the intensity and frequency of dust storms. However, the promising results were only found for one tree out of four sampled in the Catacik forest. A future study could be dedicated to verifying the presence of the Ag and Au signals in other trees in the same forest. Future studies could also analyze the ground water near sample sites to mon

  11. Tree climbing and human evolution

    PubMed Central

    Venkataraman, Vivek V.; Kraft, Thomas S.; Dominy, Nathaniel J.

    2013-01-01

    Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion in museum specimens of climbing hunter–gatherers from the Ituri forest, we did find that climbing by the Twa is associated with longer fibers in the gastrocnemius muscle relative to those of neighboring, nonclimbing agriculturalists. This result suggests that a more excursive calf muscle facilitates climbing with a bipedally adapted ankle and foot by positioning the climber closer to the tree, and it might be among the mechanisms that allow hunter–gatherers to access the canopy safely. Given that we did not find a skeletal correlate for this observed behavior, our results imply that derived aspects of the hominin ankle associated with bipedalism remain compatible with vertical climbing and arboreal resource acquisition. Our findings challenge the persistent arboreal–terrestrial dichotomy that has informed behavioral reconstructions of fossil hominins and highlight the value of using modern humans as models for inferring the limits of hominin arboreality. PMID:23277565

  12. Tree climbing and human evolution.

    PubMed

    Venkataraman, Vivek V; Kraft, Thomas S; Dominy, Nathaniel J

    2013-01-22

    Paleoanthropologists have long argued--often contentiously--about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter-gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion in museum specimens of climbing hunter-gatherers from the Ituri forest, we did find that climbing by the Twa is associated with longer fibers in the gastrocnemius muscle relative to those of neighboring, nonclimbing agriculturalists. This result suggests that a more excursive calf muscle facilitates climbing with a bipedally adapted ankle and foot by positioning the climber closer to the tree, and it might be among the mechanisms that allow hunter-gatherers to access the canopy safely. Given that we did not find a skeletal correlate for this observed behavior, our results imply that derived aspects of the hominin ankle associated with bipedalism remain compatible with vertical climbing and arboreal resource acquisition. Our findings challenge the persistent arboreal-terrestrial dichotomy that has informed behavioral reconstructions of fossil hominins and highlight the value of using modern humans as models for inferring the limits of hominin arboreality. PMID:23277565

  13. Liana competition with tropical trees varies seasonally but not with tree species identity.

    PubMed

    Leonor, Alvarez-Cansino; Schnitzer, Stefan A; Reid, Joseph P; Powers, Jennifer S

    2015-01-01

    Lianas in tropical forests compete intensely with trees for above- and belowground resources and limit tree growth and regeneration. Liana competition with adult canopy trees may be particularly strong, and, if lianas compete more intensely with some tree species than others, they may influence tree species composition. We performed the first systematic, large-scale liana removal experiment to assess the competitive effects of lianas on multiple tropical tree species by measuring sap velocity and growth in a lowland tropical forest in Panama. Tree sap velocity increased 60% soon after liana removal compared to control trees, and tree diameter growth increased 25% after one year. Although tree species varied in their response to lianas, this variation was not significant, suggesting that lianas competed similarly with all tree species examined. The effect of lianas on tree sap velocity was particularly strong during the dry season, when soil moisture was low, suggesting that lianas compete intensely with trees for water. Under the predicted global change scenario of increased temperature and drought intensity, competition from lianas may become more prevalent in seasonal tropical forests, which, according to our data, should have a negative effect on most tropical tree species. PMID:26236888

  14. Phytoremediation of trichloroethene (TCE) using cottonwood trees

    USGS Publications Warehouse

    Jones, S.A.; Lee, R.W.; Kuniansky, E.L.

    1999-01-01

    The ability of cottonwood trees for phytoremediation was studied on aerobic shallow groundwater containing TCE. Cottonwood trees were planted over a 0.2-ha area at the Naval Air Station at Fort Worth, TX, in April 1996. Two years later, groundwater chemistry in the terrace alluvial aquifer was changing locally. Dissolved oxygen (DO) concentrations declined at the southern end of the whip plantings while total iron concentration increased. Groundwater chemistry near a mature cottonwood tree ~ 60 m from the caliper trees was different from that observed elsewhere. Anaerobic conditions near the mature cottonwood tree were evident. Reductive dechlorination of TCE occurred in the aquifer near the mature tree, as demonstrated by very small concentration of TCE in groundwater, a small median ratio of TCE to the degradation product cis-1,2-DCE and the presence of vinyl chloride.

  15. Compressed Subsequence Matching and Packed Tree Coloring

    E-print Network

    Lonardi, Stefano

    } is heavy. Creates a forest where trees are rooted in the leaves of the SLP ­ the heavy forest. At most log N trees on any path from the root of the SLP to a leaf. 8 / 16 #12;New algorithm (2/2) Find first deepest node whose left hanging child (in the SLP) generates P[i]. Check if the root of the tree generates

  16. Partial alphabetic trees # Arye Barkan + Haim Kaplan +

    E-print Network

    Shamir, Ron

    . Furthermore among all such trees, T has to minimize # n i=1 w i d(w i ), where d(w i ) is the depth of w i of the optimal tree. Our algorithm relies on a solution to what we call the layered Hu#man forest problem which # n i=1 w i d F (w i ) where d F (w i ) is the depth of w i in its tree plus d j if w i # T j . Our

  17. Windthrow Mechanics: Tree Winching and Wind Tunnel

    E-print Network

    Mitchell, Stephen

    ;10/21/2003 2 Outline April: First Wind Tunnel Session May/June: Tree Winching at Malcolm Knapp Research Forest;10/21/2003 9 #12;10/21/2003 10 Tree Winching at Malcolm Knapp Research Forest Summary Averaged 2 trees per day%Crown, 33%Crown, Stem Only) #12;10/21/2003 15 August Wind Tunnel Session Deciduous species (12 species

  18. Tank waste remediation system architecture tree

    SciTech Connect

    PECK, L.G.

    1999-05-13

    The TWRS Architecture Tree presented in this document is a hierarchical breakdown to support the TWRS systems engineering analysis of the TWRS physical system, including facilities, hardware and software. The purpose for this systems engineering architecture tree is to describe and communicate the system's selected and existing architecture, to provide a common structure to improve the integration of work and resulting products, and to provide a framework as a basis for TWRS Specification Tree development.

  19. Clock tree synthesis for prescribed skew specifications 

    E-print Network

    Chaturvedi, Rishi

    2005-08-29

    of our bu?ered clock tree routing and an extension to the NS algorithm [13]. : : : : : : : : : : : : : : : : : : : : : : : : : 37 III Wirelength from our MAT algorithm and CL algorithm in [13]. The number in each parentheses is the ratio with respect... obtained by NS. : : : : : : : : : : : : : : : : : : : : : : : 32 19 Clock tree obtained by minimum merging cost based algorithm - MIC. 33 20 Clock tree obtained by maximum delay target based ordering al- gorithm - MAT...

  20. Computing with Bohm trees Ren e DAVID

    E-print Network

    David, René

    Computing with Bohm trees Ren#19;e DAVID #3; Abstract This paper develops a general technique of the theorem of Hyland and Wadsworth : two #21;-terms that have the same Bohm trees, up to (possibly in#12 to the parts of the Bohm trees that we do not have to know for an head reduction step. A theorem of Hyland

  1. Phillips goes subsea trees in Ivory Coast

    SciTech Connect

    Bryngelson, R.H.

    1982-11-15

    Describes installation of 3 wet, diver-assist trees, in the Espoir field offshore Ivory Coast, as part of Phillips Petroleum's plans to use 5 satellite wells with downhole completion equipment and subsea production trees. Simplicity in design and attention to training has resulted in an installation time of about 3 weeks for one of the largest subsea trees in the industry. Presents diagram showing the converted jackup, Dan Duke drilling unit, which supports equipment to handle production from subsea wells.

  2. Tree canopy radiance measurement system

    NASA Technical Reports Server (NTRS)

    Caldwell, William; Vanderbilt, V. C.

    1989-01-01

    A system is described for obtaining both an estimate of the spatial mean bidirectional reflectance factor (BRF) for a tree canopy (displaying a horizontally heterogeneous foliage distribution) and the statistical significance of that estimate. The system includes a manlift supporting a horizontal beam 7 m long on which are mounted four radiometers. These radiometers may be pointed, and radiance data acquired, in any of 11 view directions in the principal plane of the sun. A total of 80 data points, acquired in 3 min, were used to estimate the BRF of a walnut orchard 5 m tall and detect true differences of 12 percent of the mean approximately 90 percent of the time.

  3. Combinatorics of distance-based tree inference

    PubMed Central

    Pardi, Fabio; Gascuel, Olivier

    2012-01-01

    Several popular methods for phylogenetic inference (or hierarchical clustering) are based on a matrix of pairwise distances between taxa (or any kind of objects): The objective is to construct a tree with branch lengths so that the distances between the leaves in that tree are as close as possible to the input distances. If we hold the structure (topology) of the tree fixed, in some relevant cases (e.g., ordinary least squares) the optimal values for the branch lengths can be expressed using simple combinatorial formulae. Here we define a general form for these formulae and show that they all have two desirable properties: First, the common tree reconstruction approaches (least squares, minimum evolution), when used in combination with these formulae, are guaranteed to infer the correct tree when given enough data (consistency); second, the branch lengths of all the simple (nearest neighbor interchange) rearrangements of a tree can be calculated, optimally, in quadratic time in the size of the tree, thus allowing the efficient application of hill climbing heuristics. The study presented here is a continuation of that by Mihaescu and Pachter on branch length estimation [Mihaescu R, Pachter L (2008) Proc Natl Acad Sci USA 105:13206–13211]. The focus here is on the inference of the tree itself and on providing a basis for novel algorithms to reconstruct trees from distances. PMID:23012403

  4. Why are so many trees hollow?

    PubMed Central

    Ruxton, Graeme D.

    2014-01-01

    In many living trees, much of the interior of the trunk can be rotten or even hollowed out. Previously, this has been suggested to be adaptive, with microbial or animal consumption of interior wood producing a rain of nutrients to the soil beneath the tree that allows recycling of those nutrients into new growth via the trees roots. Here I propose an alternative (non-exclusive) explanation: such loss of wood comes at very little cost to the tree and so investment in costly chemical defence of this wood is not economic. I discuss how this theory can be tested empirically. PMID:25392312

  5. Mojave National Preserve Joshua Tree National Park

    E-print Network

    Laughlin, Robert B.

    Death Valley Mojave National Preserve Joshua Tree National Park National Park National Training California City Baker Brawley El Centro Borrego Springs Victorville Palm Desert Apple Valley Hesperia Indio

  6. Multispectral sensing of citrus young tree decline

    NASA Technical Reports Server (NTRS)

    Edwards, G. J.; Ducharme, E. P.; Schehl, T.

    1975-01-01

    Computer processing of MSS data to identify and map citrus trees affected by young tree decline is analyzed. The data were obtained at 1500-feet altitude in six discrete spectral bands covering regions from 0.53 to 1.3 millimicrons as well as from instrumental ground truths of tree crowns. Measurable spectral reflectance intensity differences are observed in the leaves of healthy and diseased trees, especially at wavelengths of 500 to 600 nm and 700 to 800 nm. The overall accuracy of the method is found to be 89%.

  7. Texas Wholesale Market for Christmas Trees

    E-print Network

    Sorensen, H. B. (Harold B.); Smith, W. A.

    1964-01-01

    A&M UNIVERSITY . TEXAS AGRICULTURAL EXPERIMENT STATION R. E. Patterson, Director, College Station, Texas trees might capture as much as one-half of the more than 2 million Texas evergreen tree market. Wl~olesale Christmas tree markets for Dallas..., Houston and San Antonio were investigated during the 1962 Holiday Season to determine potential outlets for locally grown trees. The investigation was limited to species which could be grown in at least a part of the state, but it did not include...

  8. Tree ring record chronicles major Mesoamerican droughts

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-05-01

    A new tree ring record chronicles major Mesoamerican droughts in the past millennium that may have contributed to the decline of some pre-Hispanic civilizations. Although there is other evidence of droughts during the past millennium, the paleoclimate record had gaps. Stahle et al. used core samples from Montezuma bald cypress trees found in Barranca de Amealco, Querétaro, Mexico, to develop a 1238-year tree ring chronology. They reconstructed the soil moisture record from the tree ring growth patterns. The new record provides the first dated, annually resolved climate record for Mexico and Central America spanning this time period.(Geophysical Research Letters, doi:10.1029/2010GL046472, 2011)

  9. Creating ensembles of decision trees through sampling

    DOEpatents

    Kamath, Chandrika; Cantu-Paz, Erick

    2005-08-30

    A system for decision tree ensembles that includes a module to read the data, a module to sort the data, a module to evaluate a potential split of the data according to some criterion using a random sample of the data, a module to split the data, and a module to combine multiple decision trees in ensembles. The decision tree method is based on statistical sampling techniques and includes the steps of reading the data; sorting the data; evaluating a potential split according to some criterion using a random sample of the data, splitting the data, and combining multiple decision trees in ensembles.

  10. The spectral dimension of generic trees

    E-print Network

    Bergfinnur Durhuus; Thordur Jonsson; John F. Wheater

    2006-07-11

    We define generic ensembles of infinite trees. These are limits as $N\\to\\infty$ of ensembles of finite trees of fixed size $N$, defined in terms of a set of branching weights. Among these ensembles are those supported on trees with vertices of a uniformly bounded order. The associated probability measures are supported on trees with a single spine and Hausdorff dimension $d_h =2$. Our main result is that their spectral dimension is $d_s=4/3$, and that the critical exponent of the mass, defined as the exponential decay rate of the two-point function along the spine, is 1/3.

  11. Why are so many trees hollow?

    PubMed

    Ruxton, Graeme D

    2014-11-01

    In many living trees, much of the interior of the trunk can be rotten or even hollowed out. Previously, this has been suggested to be adaptive, with microbial or animal consumption of interior wood producing a rain of nutrients to the soil beneath the tree that allows recycling of those nutrients into new growth via the trees roots. Here I propose an alternative (non-exclusive) explanation: such loss of wood comes at very little cost to the tree and so investment in costly chemical defence of this wood is not economic. I discuss how this theory can be tested empirically. PMID:25392312

  12. Understory plant communities and the functional distinction between savanna trees, forest trees, and pines.

    SciTech Connect

    Veldman, Joseph, W., Mattingly, Brett, W., Brudvig, Lars, A.

    2013-04-01

    Abstract. Although savanna trees and forest trees are thought to represent distinct functional groups with different effects on ecosystem processes, few empirical studies have examined these effects. In particular, it remains unclear if savanna and forest trees differ in their ability to coexist with understory plants, which comprise the majority of plant diversity in most savannas. We used structural equation modeling (SEM) and data from 157 sites across three locations in the southeastern United States to understand the effects of broadleaf savanna trees, broadleaf forest trees, and pine trees on savanna understory plant communities. After accounting for underlying gradients in fire frequency and soil moisture, abundances (i.e., basal area and stem density) of forest trees and pines, but not savanna trees, were negatively correlated with the cover and density (i.e., local-scale species richness) of C4 graminoid species, a defining savanna understory functional group that is linked to ecosystem flammability. In analyses of the full understory community, abundances of trees from all functional groups were negatively correlated with species density and cover. For both the C4 and full communities, fire frequency promoted understory plants directly, and indirectly by limiting forest tree abundance. There was little indirect influence of fire on the understory mediated through savanna trees and pines, which are more fire tolerant than forest trees. We conclude that tree functional identity is an important factor that influences overstory tree relationships with savanna understory plant communities. In particular, distinct relationships between trees and C4 graminoids have implications for grass-tree coexistence and vegetation-fire feedbacks that maintain savanna environments and their associated understory plant diversity.

  13. The alternating decision tree learning algorithm Yoav Freund

    E-print Network

    Freund, Yoav

    The alternating decision tree learning algorithm Yoav Freund AT&T Labs 180 Park Avenue Florham Park vote over a number of decision trees. Unfortunately, these classifiers are often large, complex tree, which is a generalization of decision trees, voted decision trees and voted decision stumps

  14. TOP-DOWN DECISION TREE INDUCERS Lev Dubinets

    E-print Network

    Morrow, James A.

    TOP-DOWN DECISION TREE INDUCERS Lev Dubinets A decision tree is a tree where each internal node is `female'". A decision tree can also be thought of as an apparatus that accepts as a set of input values and follows decision rules to get to a leaf of the tree, which corresponds to an output value. As such

  15. DIGITAL SEARCH TREES AGAIN REVISITED: THE INTERNAL PATH LENGTH PERSPECTIVE

    E-print Network

    Prodinger, Helmut

    DIGITAL SEARCH TREES AGAIN REVISITED: THE INTERNAL PATH LENGTH PERSPECTIVE Peter Kirschenhofery digital search tree. The problem was open up to now. We prove that for the binary digital search tree indicator how well the digital trees are balanced. We shall show that the digital search tree is the best

  16. Atlas of United States Trees, Volume 2: Alaska Trees and Common Shrubs.

    ERIC Educational Resources Information Center

    Viereck, Leslie A.; Little, Elbert L., Jr.

    This volume is the second in a series of atlases describing the natural distribution or range of native tree species in the United States. The 82 species maps include 32 of trees in Alaska, 6 of shrubs rarely reaching tree size, and 44 more of common shrubs. More than 20 additional maps summarize environmental factors and furnish general…

  17. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER General Provisions § 223.4 Exchange of trees...

  18. TREE TRAILS 1. Crown: (head) part of the tree that consists of the leaves and the

    E-print Network

    of the leaves and the branches at the top of a tree. 2. Leaves: (fingers) food factories of the tree. The leaves contain chlorophyll which gives leaves their green color and is responsible for photosynthesis. During from the soil into sugar and oxygen producing a chemical change. The sugar (which is the tree's food

  19. Street Tree Survey Report: Galveston, TX Addendum #1 Galveston Street Tree Survey--Addendum #1

    E-print Network

    Street Tree Survey Report: Galveston, TX Addendum #1 Galveston Street Tree Survey--Addendum #1 Following publication of the Hurricane Ike Street Tree Survey Report & Recommendations for Galveston, Texas, the authors conducted additional analysis of the data recorded during the survey of April 21-22, 2009. Crown

  20. Evolutionary models of phylogenetic trees.

    PubMed Central

    Pinelis, Iosif

    2003-01-01

    The most widely used evolutionary model for phylogenetic trees is the equal-rates Markov (ERM) model. A problem is that the ERM model predicts less imbalance than observed for trees inferred from real data; in fact, the observed imbalance tends to fall between the values predicted by the ERM model and those predicted by the proportional-to-distinguishable-arrangements (PDA) model. Here, a continuous multi-rate (MR) family of evolutionary models is presented which contains entire subfamilies corresponding to both the PDA and ERM models. Furthermore, this MR family covers an entire range from 'completely balanced' to 'completely unbalanced' models. In particular, the MR family contains other known evolutionary models. The MR family is very versatile and virtually free of assumptions on the character of evolution; yet it is highly susceptible to rigorous analyses. In particular, such analyses help to uncover adaptability, quasi-stabilization and prolonged stasis as major possible causes of the imbalance. However, the MR model is functionally simple and requires only three parameters to reproduce the observed imbalance. PMID:12965036

  1. Sulfur nutrition of deciduous trees

    NASA Astrophysics Data System (ADS)

    Herschbach, Cornelia; Rennenberg, Heinz

    2001-01-01

    Sulfur in its reduced form (-II) is an essential nutrient for growth and development, but is mainly available to plants in its oxidised form as sulfate. Deciduous trees take up sulfate by the roots from the soil solution and reduce sulfate to sulfide via assimilatory sulfate reduction in both roots and leaves. For reduction in the leaves, sulfate is loaded into the xylem and transported to the shoot. The surplus of sulfate not reduced in the chloroplast or stored in the vacuole and the surplus of reduced S not used for protein synthesis in the leaves is loaded into the phloem and transported back to the roots. Along the transport path, sulfate and glutathione (GSH) is unloaded from the phloem for storage in xylem and phloem parenchyma as well as in pit and ray cells. Re-mobilised S from storage tissues is loaded into the xylem during spring, but a phloem to xylem exchange does not appear to exist later in the season. As a consequence, a cycling pool of S was only found during the change of the seasons. The sulfate:glutathione ratio in the phloem seems to be involved in the regulation of S nutrition. This picture of S nutrition is discussed in relation to the different growth patterns of deciduous trees from the temperate climate zone, i.e. (1) terminated, (2) periodic and (3) indeterminate growth patterns, and in relation to environmental changes.

  2. Species Tree Inference Using a Mixture Model.

    PubMed

    Ullah, Ikram; Parviainen, Pekka; Lagergren, Jens

    2015-09-01

    Species tree reconstruction has been a subject of substantial research due to its central role across biology and medicine. A species tree is often reconstructed using a set of gene trees or by directly using sequence data. In either of these cases, one of the main confounding phenomena is the discordance between a species tree and a gene tree due to evolutionary events such as duplications and losses. Probabilistic methods can resolve the discordance by coestimating gene trees and the species tree but this approach poses a scalability problem for larger data sets. We present MixTreEM-DLRS: A two-phase approach for reconstructing a species tree in the presence of gene duplications and losses. In the first phase, MixTreEM, a novel structural expectation maximization algorithm based on a mixture model is used to reconstruct a set of candidate species trees, given sequence data for monocopy gene families from the genomes under study. In the second phase, PrIME-DLRS, a method based on the DLRS model (Åkerborg O, Sennblad B, Arvestad L, Lagergren J. 2009. Simultaneous Bayesian gene tree reconstruction and reconciliation analysis. Proc Natl Acad Sci U S A. 106(14):5714-5719), is used for selecting the best species tree. PrIME-DLRS can handle multicopy gene families since DLRS, apart from modeling sequence evolution, models gene duplication and loss using a gene evolution model (Arvestad L, Lagergren J, Sennblad B. 2009. The gene evolution model and computing its associated probabilities. J ACM. 56(2):1-44). We evaluate MixTreEM-DLRS using synthetic and biological data, and compare its performance with a recent genome-scale species tree reconstruction method PHYLDOG (Boussau B, Szöll?si GJ, Duret L, Gouy M, Tannier E, Daubin V. 2013. Genome-scale coestimation of species and gene trees. Genome Res. 23(2):323-330) as well as with a fast parsimony-based algorithm Duptree (Wehe A, Bansal MS, Burleigh JG, Eulenstein O. 2008. Duptree: a program for large-scale phylogenetic analyses using gene tree parsimony. Bioinformatics 24(13):1540-1541). Our method is competitive with PHYLDOG in terms of accuracy and runs significantly faster and our method outperforms Duptree in accuracy. The analysis constituted by MixTreEM without DLRS may also be used for selecting the target species tree, yielding a fast and yet accurate algorithm for larger data sets. MixTreEM is freely available at http://prime.scilifelab.se/mixtreem/. PMID:25963975

  3. The universal tree of life: an update

    PubMed Central

    Forterre, Patrick

    2015-01-01

    Biologists used to draw schematic “universal” trees of life as metaphors illustrating the history of life. It is indeed a priori possible to construct an organismal tree connecting the three major domains of ribosome encoding organisms: Archaea, Bacteria and Eukarya, since they originated by cell division from LUCA. Several universal trees based on ribosomal RNA sequence comparisons proposed at the end of the last century are still widely used, although some of their main features have been challenged by subsequent analyses. Several authors have proposed to replace the traditional universal tree with a ring of life, whereas others have proposed more recently to include viruses as new domains. These proposals are misleading, suggesting that endosymbiosis can modify the shape of a tree or that viruses originated from the last universal common ancestor (LUCA). I propose here an updated version of Woese’s universal tree that includes several rootings for each domain and internal branching within domains that are supported by recent phylogenomic analyses of domain specific proteins. The tree is rooted between Bacteria and Arkarya, a new name proposed for the clade grouping Archaea and Eukarya. A consensus version, in which each of the three domains is unrooted, and a version in which eukaryotes emerged within archaea are also presented. This last scenario assumes the transformation of a modern domain into another, a controversial evolutionary pathway. Viruses are not indicated in these trees but are intrinsically present because they infect the tree from its roots to its leaves. Finally, I present a detailed tree of the domain Archaea, proposing the sub-phylum neo-Euryarchaeota for the monophyletic group of euryarchaeota containing DNA gyrase. These trees, that will be easily updated as new data become available, could be useful to discuss controversial scenarios regarding early life evolution. PMID:26257711

  4. TREE TRAILS The trees around us those that make up the `urban forest' are a reflection of the community itself.

    E-print Network

    1 TREE TRAILS The trees around us ­ those that make up the `urban forest' ­ are a reflection of the community itself. Cities often organize the protection, planting and care of trees in public spaces, through a Tree Board or other volunteer group. Tree City USA is one symbol of a community that cares about its

  5. Decision Tree Induction Based on Efficient Tree Restructuring 1 Paul E. Utgoff utgoff@cs.umass.edu

    E-print Network

    Utgoff, Paul

    Decision Tree Induction Based on Efficient Tree Restructuring 1 Paul E. Utgoff utgoff to restructure a decision tree efficiently enables a variety of ap­ proaches to decision tree induction and classifier characteristics that lend themselves to particular applications. Keywords: decision tree

  6. Decision Tree Induction Based on Efficient Tree Restructuring1 Paul E. Utgoff utgoff@cs.umass.edu

    E-print Network

    Massachusetts at Amherst, University of

    Decision Tree Induction Based on Efficient Tree Restructuring1 Paul E. Utgoff utgoff to restructure a decision tree efficiently enables a variety of ap- proaches to decision tree induction and classifier characteristics that lend themselves to particular applications. Keywords: decision tree

  7. Street tree valuation systems Street trees and urban woodlands provide a number of environmental and social benefits, including contributing to

    E-print Network

    Street tree valuation systems Street trees and urban woodlands provide a number of environmental value of street trees: CAVAT, Helliwell and i-Tree. The review showed that the three valuation systems not prescribe how their value should be estimated. A number of urban street trees valuation systems have been

  8. Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix

    SciTech Connect

    N. Price, Morgan; S. Dehal, Paramvir; P. Arkin, Adam

    2009-07-31

    Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor interchanges to reduce the length of the tree. For an alignment with N sequences, L sites, and a different characters, a distance matrix requires O(N^2) space and O(N^2 L) time, but FastTree requires just O( NLa + N sqrt(N) ) memory and O( N sqrt(N) log(N) L a ) time. To estimate the tree's reliability, FastTree uses local bootstrapping, which gives another 100-fold speedup over a distance matrix. For example, FastTree computed a tree and support values for 158,022 distinct 16S ribosomal RNAs in 17 hours and 2.4 gigabytes of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 hours and 50 gigabytes of memory. In simulations, FastTree was slightly more accurate than neighbor joining, BIONJ, or FastME; on genuine alignments, FastTree's topologies had higher likelihoods. FastTree is available at http://microbesonline.org/fasttree.

  9. Alcohol co-production from tree crops

    SciTech Connect

    Seibert, M.; Folger, G.; Milne, T.

    1982-06-01

    A concept for the sustainable production of alcohol from fermentable substrates produced on an annual basis by the reproductive organs (pods, fruits, nuts, berries, etc.) of tree crops is presented. The advantages of tree-crop systems include suitability for use on marginal land, potential productivity equivalent to row crops, minimal maintenance and energy-input requirements, environmental compatibility, and the possibility of co-product production. Honeylocust, mesquite, and persimmon are examined as potential US tree-crop species. Other species not previously considered, including osage orange and breadfruit, are suggested as tree-crop candidates for North America and the tropical developing world, respectively. Fermentation of tree-crop organs and the economics of tree-crop systems are also discussed. Currently the greatest area of uncertainty lies in actual pod or fruit yields one can expect from large tree farms under real life conditions. However, ballpark ethanol yield estimates of from 880 to 3470 l hectare/sup -1/ (94 to 400 gal acre/sup -1/) justify further consideration of tree crop systems.

  10. LETTERSTO NATURE Anatolian tree ringsand the

    E-print Network

    Manning, Sturt

    * & MaryJaye Bruce* *The Malcolm and CarolynWiener laboratoryfor Aegeanand Near Eastern Dendrochronology has allowed the Aegean Dendrochronology Project to build absolute and floating tree-ring sequences, it is not connected at present to a fixed dendrochronology from living trees backwards. W e have dated this chronology

  11. Herbivores Promote Habitat Specialization by Trees in

    E-print Network

    Leps, Jan "Suspa"

    Herbivores Promote Habitat Specialization by Trees in Amazonian Forests Paul V. A. Fine,1,2 * Italo independent pairs of edaphic specialist trees and manipulated the presence of herbivores. Clay specialist herbivores. However, when unprotected, white-sand specialists dominated in white-sand forests and clay

  12. Propagating Belief Functions in AND-Trees

    E-print Network

    Srivastava, Rajendra P.; Shenoy, Prakash P.; Shafer, Glenn R.

    1995-01-01

    We describe a simple method for propagating belief functions in AND-trees. We exploit the properties of AND-trees to make our method simpler than the general method discussed by Shenoy and Shafer, and Dempster and Kong. We illustrate our method...

  13. CRITIQUE OF CARBON BASED TREE GROWTH MODELS

    EPA Science Inventory

    Simulation models of the processes that control carbohydrate balance in coniferous trees are reviewed, and their appropriateness for assessing pollution effects is considered. Currently such models are at the forefront of attempts to simulate the growth process of trees, but they...

  14. NOT EVERY UNIFORM TREE COVERS RAMANUJAN GRAPHS

    E-print Network

    Smirnova-Nagnibeda, Tatiana

    NOT EVERY UNIFORM TREE COVERS RAMANUJAN GRAPHS Alexander Lubotzky and Tatiana Nagnibeda Abstract. The notion of Ramanujan graph has been extended to not necessarily regular graphs by Y. Greenberg. We construct infinite trees with infinitely many finite quotients, none of which is Ramanujan. We give

  15. CONDITIONED GALTONWATSON TREES DO NOT SVANTE JANSON

    E-print Network

    Janson, Svante

    -biased Galton­Watson process, see e.g. Kennedy [6], Aldous [1], Lyons, Pemantle and Peres [8]. The sizeCONDITIONED GALTON­WATSON TREES DO NOT GROW SVANTE JANSON Abstract. An example is given which shows that, in general, condi- tioned Galton­Watson trees cannot be obtained by adding vertices one by one

  16. Molecular basis of angiosperm tree architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The shoot architecture of trees greatly impacts orchard and forest management methods. Amassing greater knowledge of the molecular genetics behind tree form can benefit these industries as well as contribute to basic knowledge of plant developmental biology. This review covers basic components of ...

  17. A Contour Method on Cayley tree

    E-print Network

    U. A. Rozikov

    2006-11-15

    We consider a finite range lattice models on Cayley tree with two basic properties: the existence of only a finite number of ground states and with Peierls type condition. We define notion of a contour for the model on the Cayley tree. By a contour argument we show the existence of $s$ different (where $s$ is the number of ground states) Gibbs measures.

  18. Bulk Operations for Space-Partitioning Trees

    E-print Network

    Ghanem, Thanaa M.; Shah, Rahul; Mokbel, Mohamed F.; Aref, Walid; Vitter, Jeffrey Scott

    2004-01-01

    The emergence of extensible index structures, e.g., GiST (Generalized Search Tree) [25] and SP-GiST (Space-Partitioning Generalized Search Tree) [3], calls for a set of extensible algorithms to support different operations (e.g., insertion, deletion...

  19. Genetic interactions underlying tree branch orientation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expanding our understanding of the molecular and genetic mechanisms behind branch orientation in trees both addresses a fundamental developmental phenomenon and can lead to significant impacts on tree crop agriculture and forestry. Using the p-nome (pooled genome) sequencing-based mapping approac...

  20. Quad Tree Structures for Image Compression Applications.

    ERIC Educational Resources Information Center

    Markas, Tassos; Reif, John

    1992-01-01

    Presents a class of distortion controlled vector quantizers that are capable of compressing images so they comply with certain distortion requirements. Highlights include tree-structured vector quantizers; multiresolution vector quantization; error coding vector quantizer; error coding multiresolution algorithm; and Huffman coding of the quad-tree

  1. The "Ride for Russia" Tree Lichen Survey

    ERIC Educational Resources Information Center

    Young, Simon

    2013-01-01

    The prevalence of nine indicator lichens found on trees in Northern Europe and Western Russia was used for monitoring air quality. The 4200 mile route of the survey went through eight countries. Surveys were carried out in cities, towns, countryside and forests, and along motorways. The author has conducted tree lichen surveys with pupils from…

  2. Algorithmic height compression of unordered trees.

    PubMed

    Ben-Naoum, Farah; Godin, Christophe

    2016-01-21

    By nature, tree structures frequently present similarities between their sub-parts. Making use of this redundancy, different types of tree compression techniques have been designed in the literature to reduce the complexity of tree structures. A popular and efficient way to compress a tree consists of merging its isomorphic subtrees, which produces a directed acyclic graph (DAG) equivalent to the original tree. An important property of this method is that the compressed structure (i.e. the DAG) has the same height as the original tree, thus limiting partially the possibility of compression. In this paper we address the problem of further compressing this DAG in height. The difficulty is that compression must be carried out on substructures that are not exactly isomorphic as they are strictly nested within each-other. We thus introduced a notion of quasi-isomorphism between subtrees that makes it possible to define similar patterns along any given path in a tree. We then proposed an algorithm to detect these patterns and to merge them, thus leading to compressed structures corresponding to DAGs augmented with return edges. In this way, redundant information is removed from the original tree in both width and height, thus achieving minimal structural compression. The complete compression algorithm is then illustrated on the compression of various plant-like structures. PMID:26551155

  3. How Trees Help the Power Company!

    ERIC Educational Resources Information Center

    King, Rik

    1992-01-01

    Proposes the utilization of graph theory to solve optimization problems. Defines the notion of spanning trees and presents two algorithms to determine optimization of a spanning tree. Discusses an example to connect towns by power transmission lines at minimum cost. (MDH)

  4. REPRESENTING RECTILINEAR STEINER TREES IN GENETIC ALGORITHMS

    E-print Network

    Julstrom, Bryant A.

    of Computer Science St. Cloud State University 720 Fourth Avenue South St. Cloud, MN 56301 julstrom and with popula- tions seeded with a single chromosome that represented a short rectilinear Steiner tree. The algorithm identi- #12;ed much shorter trees using the weighted coding, and seeding the population improved

  5. Efficient Algorithms for the Tree Homeomorphism Problem

    E-print Network

    Martens, Wim

    Efficient Algorithms for the Tree Homeomorphism Problem Michaela G¨otz1 , Christoph Koch1 , and Wim of Dortmund Dortmund, Germany wim.martens@udo.edu Abstract. Tree pattern matching is a fundamental problem by a scholarship of the FWO-Vlaanderen that permitted Wim Martens to visit the Technical University of Vienna

  6. Trees in Art, Literature, and Nature.

    ERIC Educational Resources Information Center

    Herzberg, Catherine Kenton

    1997-01-01

    Outlines a grade 5 unit on trees combining art, science, math. language arts, social studies, history, and technology. Highlights "Sky Tree" written by Candace Christiansen and illustrated by Thomas Locker. Provides an annotated bibliography (K-5) of picture and information books, fiction, and videos, and describes art and content area activities.…

  7. Deforestation: Transforming programs to eliminate trees

    E-print Network

    Wadler, Philip

    Deforestation: Transforming programs to eliminate trees Philip Wadler University of Glasgow \\Lambda---called the Deforestation Algorithm. A form of function definition that uses no intermediate trees is characterised, called and the Deforestation Algorithm are presented in three steps. The first step presents ``pure'' treeless form in a first

  8. Natural products as herbicides for tree establishment

    E-print Network

    Natural products as herbicides for tree establishment D.V. CLAY1 , F.L. DIXON1 AND I. WILLOUGHBY2-product herbicides bilanaphos and citronella oil were tested in comparison with glufosinate-ammonium. When applied-product herbicides are of potential use for tree establishment but costs of development and registration may

  9. When Bad Things Happen to Good Trees

    E-print Network

    Gordon, Gary

    (for a scienti®c survey of Mars or a remote volcano or perhaps for a spying mission) and then relaying for both trees and rooted trees, one of which is especially simple in each case. We also prove two extremal rank polynomial 1. INTRODUCTION No one seems to notice systems when they are operating normally

  10. Signature Tree Generation for Polymorphic Worms

    E-print Network

    Xiao, Bin

    Signature Tree Generation for Polymorphic Worms Yong Tang, Bin Xiao, Member, IEEE, and Xicheng Lu generate accurate signatures for worms, especially polymorphic worms. In this paper, we propose a new NSG system--PolyTree, to defend against polymorphic worms. We observe that signatures from worms

  11. The Tree Man: Robert Mazibuko's Story.

    ERIC Educational Resources Information Center

    Bloch, Joanne, Ed.

    This book for beginning readers highlights Robert Mazibuko, the "Tree Man," who spent his life teaching people how to enrich the soil and plant vegetables and trees. Born in South Africa in 1904, he lived on a farm, learning to work with livestock, raise crops, and share with the community. In college, his professor of agriculture provided a…

  12. 29 CFR 780.208 - Forest and Christmas tree activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Forest and Christmas tree activities. 780...and Landscaping Operations § 780.208 Forest and Christmas tree activities. Operations in a forest tree nursery such as seeding new beds...

  13. 29 CFR 780.208 - Forest and Christmas tree activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Forest and Christmas tree activities. 780...and Landscaping Operations § 780.208 Forest and Christmas tree activities. Operations in a forest tree nursery such as seeding new beds...

  14. 29 CFR 780.208 - Forest and Christmas tree activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Forest and Christmas tree activities. 780...and Landscaping Operations § 780.208 Forest and Christmas tree activities. Operations in a forest tree nursery such as seeding new beds...

  15. 29 CFR 780.208 - Forest and Christmas tree activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Forest and Christmas tree activities. 780...and Landscaping Operations § 780.208 Forest and Christmas tree activities. Operations in a forest tree nursery such as seeding new beds...

  16. 29 CFR 780.208 - Forest and Christmas tree activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Forest and Christmas tree activities. 780...and Landscaping Operations § 780.208 Forest and Christmas tree activities. Operations in a forest tree nursery such as seeding new beds...

  17. THE WIENER INDEX OF SIMPLY GENERATED RANDOM TREES

    E-print Network

    Janson, Svante

    THE WIENER INDEX OF SIMPLY GENERATED RANDOM TREES moments as well as for the distribution of the Wiener index of a random tree from a simply generated family (or, equivalently, a critical Galton- Watson tree). We also establish a joint

  18. M______ S________ '13 Working Title: Know Your Trees!

    E-print Network

    Snider, Barry B.

    M______ S________ '13 Working Title: Know Your Trees! Type of Project with the road leading from the Village to Rabb, ID all the trees, and then attach semi-permanent labels with each tree's Latin and English names. Each label

  19. Tools for Protecting Trees from ACP Phil Stansly

    E-print Network

    Ma, Lena

    for growing season depending on pest populations ­ Systemic insecticides for young trees ­ Thresholds Selective Insecticides during Growing Season #12;· `Valencia' orange trees planted 1998 · Trees pruned for Pest Management Dormant Growing ­ Efficacy · Adults/nymphs · Secondary pests ­ Resistance management

  20. 16 CFR 501.2 - Christmas tree ornaments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial...PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled for retail...

  1. 16 CFR 501.2 - Christmas tree ornaments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial...PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled for retail...

  2. 16 CFR 501.2 - Christmas tree ornaments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial...PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled for retail...

  3. 16 CFR 501.2 - Christmas tree ornaments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial...PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled for retail...

  4. 16 CFR 501.2 - Christmas tree ornaments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial...PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled for retail...

  5. Tree snubbing operation solves well control problem

    SciTech Connect

    Gebhardt, F.; Thompson, J.D.

    1987-09-01

    Wild Well Control, Inc. has used a unique method to remove a Christmas tree under high pressure and install BOPs without a rig. This allowed workover of a gas-condensate well with a shallow tubing break that could not be killed by surface pumping due to casing pressure limitations. The procedure eliminated the need for drilling a relief well. The tree-stripping procedure is applicable to wells with Christmas trees that are screwed to the tubing string and equipped with wrap-around tubing hangers. The method would not be required if the tree were provided with a mandrel hanger that could receive a back-pressure valve. The step-by-step procedure used to remove the tree under pressure is described.

  6. Robins gather in a tree

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In a wooded area of Kennedy Space Center, robins gather on a tree branch just beginning to show new Spring growth. A member of the thrush family, robins inhabit towns, gardens, open woodlands and agricultural lands. They range through most of North America, spending winters in large roosts mostly in the United States but also Newfoundland, southern Ontario and British Columbia. The Center shares a boundary with the Merritt Island National Wildlife Refuge, a haven and habitat for more than 331 species of birds. The Refuge encompasses 92,000 acres that are also a habitat for 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  7. A-3 First Tree Cutting

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Tree clearing for the site of the new A-3 Test Stand at Stennis Space center began June 13. NASA's first new large rocket engine test stand to be built since the site's inception, A-3 construction begins a historic era for America's largest rocket engine test complex. The 300-foot-tall structure is scheduled for completion in August 2010. A-3 will perform altitude tests on the Constellation's J-2X engine that will power the upper stage of the Ares I crew launch vehicle and earth departure stage of the Ares V cargo launch vehicle. The Constellation Program, NASA's plan for carrying out the nation's Vision for Space Exploration, will return humans to the moon and eventually carry them to Mars and beyond.

  8. Finding the tree of life: matching phylogenetic trees to the fossil record through the 20th century

    E-print Network

    Benton, Michael

    Finding the tree of life: matching phylogenetic trees to the fossil record through the 20th century in their performance. Keywords: cladistics; phylogeny; fossil record; stratigraphy; tree 1. INTRODUCTION Systematics

  9. Language distance and tree reconstruction

    NASA Astrophysics Data System (ADS)

    Petroni, Filippo; Serva, Maurizio

    2008-08-01

    Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.

  10. Derived operating rules for a reservoir operation system: Comparison of decision trees, neural decision trees and fuzzy decision trees

    NASA Astrophysics Data System (ADS)

    Wei, Chih-Chiang; Hsu, Nien-Sheng

    2008-02-01

    This article compares the decision-tree algorithm (C5.0), neural decision-tree algorithm (NDT) and fuzzy decision-tree algorithm (FIDs) for addressing reservoir operations regarding water supply during normal periods. The conventional decision-tree algorithm, such as ID3 and C5.0, executes rapidly and can easily be translated into if-then-else rules. However, the C5.0 algorithm cannot discover dependencies among attributes and cannot treat the non-axis-parallel class boundaries of data. The basic concepts of the two algorithms presented are: (1) NDT algorithm combines the neural network technologies and conventional decision-tree algorithm capabilities, and (2) FIDs algorithm extends to apply fuzzy sets for all attributes with membership function grades and generates a fuzzy decision tree. In order to obtain higher classification rates in FIDs, the flexible trapezoid fuzzy sets are employed to define membership functions. Furthermore, an intelligent genetic algorithm is utilized to optimize the large number of variables in fuzzy decision-tree design. The applicability of the presented algorithms is demonstrated through a case study of the Shihmen Reservoir system. A network flow optimization model for analyzing long-term supply demand is employed to generate the input-output patterns. Findings show superior performance of the FIDs model in contrast with C5.0, NDT and current reservoir operating rules.

  11. Rainfall and Streamflow from Small Tree-Covered and

    E-print Network

    Rainfall and Streamflow from Small Tree-Covered and Fern-Covered and Burned Watersheds ------------------------------------------------------------------------------3 Tree-Covered Watershed 3 Fern-Covered Watershed

  12. 469revision:1994-01-28modified:2002-07-16 Planting Kurepa Trees And Killing JechKunen Trees

    E-print Network

    Shelah, Saharon

    469revision:1994-01-28modified:2002-07-16 Planting Kurepa Trees And Killing Jech­Kunen Trees In a Model By Using One Inaccessible Cardinal 1 Saharon Shelah2 and Renling Jin Abstract By an 1­tree we mean a tree of power 1 and height 1 . Under CH and 21 > 2 we call an 1­tree a Jech­Kunen tree if it has many

  13. Benefits of tree mixes in carbon plantings

    NASA Astrophysics Data System (ADS)

    Hulvey, Kristin B.; Hobbs, Richard J.; Standish, Rachel J.; Lindenmayer, David B.; Lach, Lori; Perring, Michael P.

    2013-10-01

    Increasingly governments and the private sector are using planted forests to offset carbon emissions. Few studies, however, examine how tree diversity -- defined here as species richness and/or stand composition -- affects carbon storage in these plantings. Using aboveground tree biomass as a proxy for carbon storage, we used meta-analysis to compare carbon storage in tree mixtures with monoculture plantings. Tree mixes stored at least as much carbon as monocultures consisting of the mixture's most productive species and at times outperformed monoculture plantings. In mixed-species stands, individual species, and in particular nitrogen-fixing trees, increased stand biomass. Further motivations for incorporating tree richness into planted forests include the contribution of diversity to total forest carbon-pool development, carbon-pool stability and the provision of extra ecosystem services. Our findings suggest a two-pronged strategy for designing carbon plantings including: (1) increased tree species richness; and (2) the addition of species that contribute to carbon storage and other target functions.

  14. Exploiting graph properties of game trees

    SciTech Connect

    Plaat, A.; Pijls, W.; Bruin, A. de; Schaeffer, J.

    1996-12-31

    The state space of most adversary games is a directed graph. However, due to the success of simple recursive algorithms based on alpha-beta, theoreticians and practitioners have concentrated on the traversal of trees, giving the field the name {open_quotes}game-tree search,{close_quotes} This paper shows that the focus on trees has obscured some important properties of the underlying graphs. One of the hallmarks of the field of game-tree search has been the notion of the minimal tree, the smallest tree that has to be searched by any algorithm to find the minimax value. In fact, for most games it is a directed graph. As demonstrated in chess and checkers, we show that the minimal graph is significantly smaller than previously thought, proving that there is more room for improvement of current algorithms. We exploit the graph properties of the search space to reduce the size of trees built in practice by at least 25%. For over a decade, fixed-depth alpha-beta searching has been considered a closed subject, with research moving on to more application-dependent techniques. This work opens up new avenues of research for further application-independent improvements.

  15. A Modified TreePM Code

    E-print Network

    Nishikanta Khandai; J. S. Bagla

    2009-04-24

    We discuss the performance characteristics of using the modification of the tree code suggested by Barnes \\citep{1990JCoPh..87..161B} in the context of the TreePM code. The optimisation involves identifying groups of particles and using only one tree walk to compute force for all the particles in the group. This modification has been in use in our implementation of the TreePM code for some time, and has also been used by others in codes that make use of tree structures. In this paper, we present the first detailed study of the performance characteristics of this optimisation. We show that the modification, if tuned properly can speed up the TreePM code by a significant amount. We also combine this modification with the use of individual time steps and indicate how to combine these two schemes in an optimal fashion. We find that the combination is at least a factor of two faster than the modified TreePM without individual time steps. Overall performance is often faster by a larger factor, as the scheme of groups optimises use of cache for large simulations.

  16. ASTRID: Accurate Species TRees from Internode Distances

    PubMed Central

    2015-01-01

    Background Incomplete lineage sorting (ILS), modelled by the multi-species coalescent (MSC), is known to create discordance between gene trees and species trees, and lead to inaccurate species tree estimations unless appropriate methods are used to estimate the species tree. While many statistically consistent methods have been developed to estimate the species tree in the presence of ILS, only ASTRAL-2 and NJst have been shown to have good accuracy on large datasets. Yet, NJst is generally slower and less accurate than ASTRAL-2, and cannot run on some datasets. Results We have redesigned NJst to enable it to run on all datasets, and we have expanded its design space so that it can be used with different distance-based tree estimation methods. The resultant method, ASTRID, is statistically consistent under the MSC model, and has accuracy that is competitive with ASTRAL-2. Furthermore, ASTRID is much faster than ASTRAL-2, completing in minutes on some datasets for which ASTRAL-2 used hours. Conclusions ASTRID is a new coalescent-based method for species tree estimation that is competitive with the best current method in terms of accuracy, while being much faster. ASTRID is available in open source form on github. PMID:26449326

  17. Decision Tree Technique for Particle Identification

    SciTech Connect

    Quiller, Ryan

    2003-09-05

    Particle identification based on measurements such as the Cerenkov angle, momentum, and the rate of energy loss per unit distance (-dE/dx) is fundamental to the BaBar detector for particle physics experiments. It is particularly important to separate the charged forms of kaons and pions. Currently, the Neural Net, an algorithm based on mapping input variables to an output variable using hidden variables as intermediaries, is one of the primary tools used for identification. In this study, a decision tree classification technique implemented in the computer program, CART, was investigated and compared to the Neural Net over the range of momenta, 0.25 GeV/c to 5.0 GeV/c. For a given subinterval of momentum, three decision trees were made using different sets of input variables. The sensitivity and specificity were calculated for varying kaon acceptance thresholds. This data was used to plot Receiver Operating Characteristic curves (ROC curves) to compare the performance of the classification methods. Also, input variables used in constructing the decision trees were analyzed. It was found that the Neural Net was a significant contributor to decision trees using dE/dx and the Cerenkov angle as inputs. Furthermore, the Neural Net had poorer performance than the decision tree technique, but tended to improve decision tree performance when used as an input variable. These results suggest that the decision tree technique using Neural Net input may possibly increase accuracy of particle identification in BaBar.

  18. Sofic and Almost of Finite Type Tree-Shifts

    NASA Astrophysics Data System (ADS)

    Aubrun, Nathalie; Béal, Marie-Pierre

    We introduce the notion of sofic tree-shifts which corresponds to symbolic dynamical systems of infinite trees accepted by finite tree automata. We show that, contrary to shifts of infinite sequences, there is no unique minimal deterministic irreducible tree automaton accepting an irreducible sofic tree-shift, but that there is a unique synchronized one, called the Shannon cover of the tree-shift. We define the notion of almost finite type tree-shift which is a meaningful intermediate dynamical class in between irreducible finite type tree-shifts and irreducible sofic tree-shifts. We characterize the Shannon cover of an almost finite type tree-shift and we design an algorithm to check whether a sofic tree-shift is almost of finite type.

  19. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    PubMed

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment. PMID:26594707

  20. Tree Death Study's Climate Change Connections

    ScienceCinema

    McDowell, Nate

    2014-06-25

    What are the exact physiological mechanisms that lead to tree death during prolonged drought and rising temperatures? These are the questions that scientists are trying to answer at a Los Alamos National Laboratory research project called SUMO. SUMO stands for SUrvival/MOrtality study; it's a plot of land on the Lab's southern border that features 18 climate controlled tree study chambers and a large drought structure that limits rain and snowfall. Scientists are taking a wide variety of measurements over a long period of time to determine what happens during drought and warming, and what the connections and feedback loops might be between tree death and climate change.

  1. Tree Death Study's Climate Change Connections

    SciTech Connect

    McDowell, Nate

    2012-09-10

    What are the exact physiological mechanisms that lead to tree death during prolonged drought and rising temperatures? These are the questions that scientists are trying to answer at a Los Alamos National Laboratory research project called SUMO. SUMO stands for SUrvival/MOrtality study; it's a plot of land on the Lab's southern border that features 18 climate controlled tree study chambers and a large drought structure that limits rain and snowfall. Scientists are taking a wide variety of measurements over a long period of time to determine what happens during drought and warming, and what the connections and feedback loops might be between tree death and climate change.

  2. Trees and Shrubs in Northwest Texas. 

    E-print Network

    Gaines, Frank; Karper, R. E. (Robert Earl); Jones, D. L. (Don L.)

    1932-01-01

    of the best varieties for yandh roadside, and windbreak plantings. It is a drouth- resistant, rapid-growing tree, well adapted to this part of the State. The "----I ash, Honey locust, Soft maple, American elm, and Russian mulberry lther deciduous trees... Cultivation and Care: Trees, like any crop, make a more rapid gron-th where they have the entire use of the soil. It is unreasonable to expect them to compete with weeds and native grass, so that, when possible, they should be cultivated like any farm crop...

  3. Chlorinated ethenes from groundwater in tree trunks

    USGS Publications Warehouse

    Vroblesky, D.A.; Nietch, C.T.; Morris, J.T.

    1999-01-01

    The purpose of this investigation was to determine whether tree-core analysis could be used to delineate shallow groundwater contamination by chlorinated ethenes. Analysis of tree- Cores from bald cypress [Taxodium distichum (L.) Rich], tupelo (Nyssa aquatica L.), sweet gum (Liquidambar stryaciflua L.), oak (Quercus spp.), sycamore (Platanus occidentalis L.), and Ioblolly pine (Pinus taeda L.) growing over shallow groundwater contaminated with cis-1,2-dichloroethene (cDCE) and trichloroethene (TCE) showed that those compounds also were present in the trees. The cores were collected and analyzed by headspace gas chromatography. Bald cypress, tupelo, and loblolly pine contained the highest concentrations of TCE, with lesser amounts in nearby oak and sweet gum. The concentrations of cDCE and TCE in various trees appeared to reflect the configuration of the chlorinated-solvent groundwater contamination plume. Bald cypress cores collected along 18.6-m vertical transects of the same trunks showed that TCE concentrations decline by 30- 70% with trunk height. The ability of the tested trees to take up cDCE and TCE make tree coring a potentially cost-effective and simple approach to optimizing well placement at this site.The purpose of this investigation was to determine whether tree-core analysis could be used to delineate shallow groundwater contamination by chlorinated ethenes. Analysis of tree cores from bald cypress [Taxodium distichum (L.) Rich], tupelo (Nyssa aquatica L.), sweet gum (Liquidambar stryaciflua L.), oak (Quercus spp.), sycamore (Platanus occidentalis L.), and loblolly pine (Pinus taeda L.) growing over shallow groundwater contaminated with cis-1,2-dichloroethene (cDCE) and trichloroethene (TCE) showed that those compounds also were present in the trees. The cores were collected and analyzed by headspace gas chromatography. Bald cypress, tupelo, and loblolly pine contained the highest concentrations of TCE, with lesser amounts in nearby oak and sweet gum. The concentrations of cDCE and TCE in various trees appeared to reflect the configuration of the chlorinated-solvent groundwater contamination plume. Bald cypress cores collected along 18.6-m vertical transects of the same trunks showed that TCE concentrations decline by 30-70% with trunk height. The ability of the tested trees to take up cDCE and TCE make tree coring a potentially cost-effective and simple approach to optimizing well placement at this site.

  4. The decision tree approach to classification

    NASA Technical Reports Server (NTRS)

    Wu, C.; Landgrebe, D. A.; Swain, P. H.

    1975-01-01

    A class of multistage decision tree classifiers is proposed and studied relative to the classification of multispectral remotely sensed data. The decision tree classifiers are shown to have the potential for improving both the classification accuracy and the computation efficiency. Dimensionality in pattern recognition is discussed and two theorems on the lower bound of logic computation for multiclass classification are derived. The automatic or optimization approach is emphasized. Experimental results on real data are reported, which clearly demonstrate the usefulness of decision tree classifiers.

  5. Algorithms for optimal dyadic decision trees

    SciTech Connect

    Hush, Don; Porter, Reid

    2009-01-01

    A new algorithm for constructing optimal dyadic decision trees was recently introduced, analyzed, and shown to be very effective for low dimensional data sets. This paper enhances and extends this algorithm by: introducing an adaptive grid search for the regularization parameter that guarantees optimal solutions for all relevant trees sizes, revising the core tree-building algorithm so that its run time is substantially smaller for most regularization parameter values on the grid, and incorporating new data structures and data pre-processing steps that provide significant run time enhancement in practice.

  6. IND - THE IND DECISION TREE PACKAGE

    NASA Technical Reports Server (NTRS)

    Buntine, W.

    1994-01-01

    A common approach to supervised classification and prediction in artificial intelligence and statistical pattern recognition is the use of decision trees. A tree is "grown" from data using a recursive partitioning algorithm to create a tree which has good prediction of classes on new data. Standard algorithms are CART (by Breiman Friedman, Olshen and Stone) and ID3 and its successor C4 (by Quinlan). As well as reimplementing parts of these algorithms and offering experimental control suites, IND also introduces Bayesian and MML methods and more sophisticated search in growing trees. These produce more accurate class probability estimates that are important in applications like diagnosis. IND is applicable to most data sets consisting of independent instances, each described by a fixed length vector of attribute values. An attribute value may be a number, one of a set of attribute specific symbols, or it may be omitted. One of the attributes is delegated the "target" and IND grows trees to predict the target. Prediction can then be done on new data or the decision tree printed out for inspection. IND provides a range of features and styles with convenience for the casual user as well as fine-tuning for the advanced user or those interested in research. IND can be operated in a CART-like mode (but without regression trees, surrogate splits or multivariate splits), and in a mode like the early version of C4. Advanced features allow more extensive search, interactive control and display of tree growing, and Bayesian and MML algorithms for tree pruning and smoothing. These often produce more accurate class probability estimates at the leaves. IND also comes with a comprehensive experimental control suite. IND consists of four basic kinds of routines: data manipulation routines, tree generation routines, tree testing routines, and tree display routines. The data manipulation routines are used to partition a single large data set into smaller training and test sets. The generation routines are used to build classifiers. The test routines are used to evaluate classifiers and to classify data using a classifier. And the display routines are used to display classifiers in various formats. IND is written in C-language for Sun4 series computers. It consists of several programs with controlling shell scripts. Extensive UNIX man entries are included. IND is designed to be used on any UNIX system, although it has only been thoroughly tested on SUN platforms. The standard distribution medium for IND is a .25 inch streaming magnetic tape cartridge in UNIX tar format. An electronic copy of the documentation in PostScript format is included on the distribution medium. IND was developed in 1992.

  7. Regenerative tree growth: binary self-similar continuum random trees and Poisson-Dirichlet compositions

    E-print Network

    Pitman, Jim

    2008-01-01

    We use a natural ordered extension of the Chinese Restaurant Process to grow a two-parameter family of binary self-similar continuum fragmentation trees. We provide an explicit embedding of Ford's sequence of alpha model trees in the continuum tree which we identified in a previous article as a distributional scaling limit of Ford's trees. In general, the Markov branching trees induced by the two-parameter growth rule are not sampling consistent, so the existence of compact limiting trees cannot be deduced from previous work on the sampling consistent case. We develop here a new approach to establish such limits, based on regenerative interval partitions and the urn-model description of sampling from Dirichlet random distributions.

  8. Current and Potential Tree Locations in Tree Line Ecotone of Changbai Mountains, Northeast China: The Controlling Effects of Topography

    PubMed Central

    Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

    2014-01-01

    Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountains. To test the hypothesis, we used IKONOS images and WorldView-1 image to identify the tree locations and developed a logistic regression model using topographical variables to identify the dominant controls of the tree locations. The results showed that aspect, wetness, and slope were dominant controls for tree locations on western side of the mountains, whereas altitude, SPI, and aspect were the dominant factors on northern side. The upmost altitude a tree can currently reach was 2140 m asl on the northern side and 2060 m asl on western side. The model predicted results showed that habitats above the current tree line on the both sides were available for trees. Tree recruitments under the current tree line may take advantage of the available habitats at higher elevations based on the current tree location. Our research confirmed the controlling effects of topography on the tree locations in the tree line ecotone of Changbai Mountains and suggested that it was essential to assess the tree response to topography in the research of tree line ecotone. PMID:25170918

  9. Pendelluft in the bronchial tree

    PubMed Central

    Greenblatt, Elliot E.; Butler, James P.; Venegas, Jose G.

    2014-01-01

    Inhomogeneous inflation or deflation of the lungs can cause dynamic pressure differences between regions and lead to interregional airflows known as pendelluft. This work first uses analytical tools to clarify the theoretical limits of pendelluft at a single bifurcation. It then explores the global and regional pendelluft that may occur throughout the bronchial tree in a realistic example using an in silico model of bronchoconstriction. The theoretical limits of pendelluft volume exchanged at a local bifurcation driven by sinusoidal breathing range from 15.5% to 41.4% depending on the relative stiffness of the subtended regions. When nonsinusoidal flows are considered, pendelluft can be as high as 200% inlet tidal volume (Vin). At frequencies greater than 10 Hz, the inertia of the air in the airways becomes important, and the maximal local pendelluft is theoretically unbounded, even with sinusoidal breathing. In a single illustrative numerical simulation of bronchoconstriction with homogenous compliances, the overall magnitude of global pendelluft volume was <2% of the tidal volume. Despite the small overall magnitude, pendelluft volume exchange was concentrated in poorly ventilated regions of the lung, including local pendelluft at bifurcations of up to 13% Vin. This example suggests that pendelluft may be an important phenomena contributing to regional gas exchange, irreversible mixing, and aerosol deposition patterns inside poorly ventilated regions of the lung. The analytical results support the concept that pendelluft may be more prominent in diseases with significant heterogeneity in both resistance and compliance. PMID:25170072

  10. Dealing with Storm-Damaged Trees (Spanish) 

    E-print Network

    Kirk, Melanie; Taylor, Eric; Foster, C. Darwin

    2007-10-08

    Many homeowners need help caring for or removing damaged trees after a natural disaster. This publication explains what a certified arborist is and how to select one. It also cautions against burning debris downed by a storm....

  11. Controlling Tree Squirrels in Urban Areas 

    E-print Network

    Texas Wildlife Services

    2006-09-06

    In urban areas, tree squirrels can become pests when they eat pecans, berries, bird seed or vegetables from home gardens, or when they nest in attics. This leaflet discusses control of squirrels by fencing, trapping, poisoning and shooting....

  12. Practice Guide Raising trees and shrubs

    E-print Network

    E: publications@forestry.gsi.gov.uk The author may be contacted at: Forest Research Alice Holt Lodge principally at people interested in raising small numbers of trees ­ to plant in the garden, raise for bonsai

  13. Fertilizing Trees and Shrubs Why fertilize?

    E-print Network

    New Hampshire, University of

    additional fertilizer. Competing shrubs and trees in landscape beds often benefit from fertilization to growth of algae and have other biological effects. In addition, the effects of diseases, insects

  14. Asian Longhorned Beetle and its Host Trees

    E-print Network

    Vermont, University of

    Asian Longhorned Beetle and its Host Trees United States Department of Agriculture Forest.........................................................................2 Description of the Asian Longhorned Beetle.......................5 Adults ............................................................................6 Anoplophora glabripennis form nobilis ...................7 Common Asian Longhorned Beetle Look

  15. Pareto-optimal phylogenetic tree reconciliation

    E-print Network

    Libeskind-Hadas, Ran

    Motivation: Phylogenetic tree reconciliation is a widely used method for reconstructing the evolutionary histories of gene families and species, hosts and parasites and other dependent pairs of entities. Reconciliation is ...

  16. Systolic tree implementation of data structures

    SciTech Connect

    Chang, J.H.; Ibarra, O.H.; Chung, M.J.; Rao, K.K.

    1988-06-01

    The authors present systolic tree architectures for data structures such as stacks, queues, dequeues, priority queues, and dictionary machines. The stack, queue, and dequeue have a unit response time and a unit pipeline interval. The priority queue also has a unit response time, but the pipeline interval is 2. The response time and pipeline interval for the dictionary machine are O(log n) and O(1), respectively, where n is the number of data elements currently residing in the tree. In each node of the tree, the mechanism for controlling the transmission and distribution of data is finite state. This feature makes the designs presented here suitable for VLSI. If there are n data elements in the data structure, the depth of the tree is O(log n).

  17. Constructing event trees for volcanic crises

    USGS Publications Warehouse

    Newhall, C.; Hoblitt, R.

    2002-01-01

    Event trees are useful frameworks for discussing probabilities of possible outcomes of volcanic unrest. Each branch of the tree leads from a necessary prior event to a more specific outcome, e.g., from an eruption to a pyroclastic flow. Where volcanic processes are poorly understood, probability estimates might be purely empirical - utilizing observations of past and current activity and an assumption that the future will mimic the past or follow a present trend. If processes are better understood, probabilities might be estimated from a theoritical model, either subjectively or by numerical simulations. Use of Bayes' theorem aids in the estimation of how fresh unrest raises (or lowers) the probabilities of eruptions. Use of event trees during volcanic crises can help volcanologists to critically review their analysis of hazard, and help officials and individuals to compare volcanic risks with more familiar risks. Trees also emphasize the inherently probabilistic nature of volcano forecasts, with multiple possible outcomes.

  18. The Apple Tree Curriculum Approach in Korea

    ERIC Educational Resources Information Center

    Lee, Mu Keun; Phipps, Lloyd J.

    1978-01-01

    The authors discuss educational objectives of agricultural high schools in the Republic of Korea, likening the curriculum elements and subsystems to the roots, trunk, and branches of an apple tree. (MF)

  19. job," said Professor of Economics Scott Trees.

    E-print Network

    with a talk by Professor Scott Trees. One way to ensure a job after graduation is through internships. "A lot Buddies, the impact of Jack- ie's service has extended well beyond cam- pus. Building on her junior year

  20. Deforestation: Transforming programs to eliminate trees

    E-print Network

    Wadler, Philip

    Deforestation: Transforming programs to eliminate to eliminate inter* *mediate lists_and intermediate trees_called the Deforestation Algorithm. A form of fun. Treeless form and the Deforestation Algorithm are presented in three steps. * *The first step presents

  1. New bounds on optimal binary search trees

    E-print Network

    Harmon, Dion (Dion Kane)

    2006-01-01

    Binary search trees (BSTs) are a class of simple data structures used to store and access keys from an ordered set. They have been around for about half a century. Despite their ubiquitous use in practical programs, ...

  2. Locating POPs Sources with Tree Bark.

    PubMed

    Peverly, Angela A; Salamova, Amina; Hites, Ronald A

    2015-12-01

    Locating sources of persistent organic pollutants (POPs) to the atmosphere can sometimes be difficult. We suggest that tree bark makes an excellent passive atmospheric sampler and that spatial analysis of tree bark POPs concentrations can often pinpoint their sources. This is an effective strategy because tree bark is lipophilic and readily adsorbs and collects POPs from the atmosphere. As such, tree bark is an ideal sampler to find POPs sources globally, regionally, or locally. This article summarizes some work on this subject with an emphasis on kriged maps and a simple power-law model, both of which have been used to locate sources. Three of the four examples led directly to the pollutant's manufacturing plant. PMID:25629888

  3. Communicating Phylogeny: Evolutionary Tree Diagrams in Museums

    E-print Network

    MacDonald, Teresa; Wiley, Edward O.

    2012-01-01

    Tree of life diagrams are graphic representations of phylogeny—the evolutionary history and relationships of lineages—and as such these graphics have the potential to convey key evolutionary ideas and principles to a variety ...

  4. Faster generation of random spanning trees

    E-print Network

    Ma?dry, Aleksander

    2009-01-01

    In this thesis, we set forth a new algorithm for generating approximately uniformly random spanning trees in undirected graphs. We show how to sample from a distribution that is within a multiplicative (1+6) of uniform in ...

  5. Tree-Adjoining Grammars Are Not Closed Under Strong Lexicalization

    E-print Network

    that the new grammar generates exactly the same set of parse trees as G. As a special case, this entailsTree-Adjoining Grammars Are Not Closed Under Strong Lexicalization Marco Kuhlmann Uppsala University Giorgio Satta University of Padua A lexicalized tree-adjoining grammar is a tree-adjoining grammar

  6. Implicit Modeling of Tree Surfaces John C. Hart

    E-print Network

    points. The bark of trees has been observed to follow the force ow lines of the tree, and a particle ow approximation is used to simulate the texturing of bark on trees at branching points. Since trees are commonly identi ed by the appearance of their bark, we have also attempted to model bark that is typical

  7. Integral trees homeomorphic to a double star A. E. Brouwer

    E-print Network

    Brouwer, Andries E.

    Integral trees homeomorphic to a double star A. E. Brouwer 2009-09-17 Abstract Trees with two of degree larger than two. They write We would now like to examine the trees homeomorphic to a double star, that is, to a tree obtained by joining the centers of two stars with an edge. Unfortunately, the details

  8. A Spring Playscape Project: Building a Tree Circle

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2009-01-01

    The Tree Circle is a green gathering area for children made by planting trees in a circle. For children, the Tree Circle becomes a magical place for dramatic play, quiet retreat, or lively nature exploration. For teachers and parents it becomes a shady grove for snacks and stories. The trees create a sweet spot that changes during the seasons and…

  9. Growing Greener Cities: A Tree-Planting Handbook.

    ERIC Educational Resources Information Center

    Moll, Gary; Young, Stanley

    This step-by-step guide, developed by the Global ReLeaf organization, presents tree-planting advice and simple steps to organizing a successful community tree-planting and tree-care program. The text is divided into three parts. Part 1 introduces trees and discusses the role they play as components of the living urban environment. Distinctions are…

  10. GPU Ray Tracing k-D tree 133 "( IC 2010)"

    E-print Network

    Yang, Sung-Bong

    GPU Ray Tracing k-D tree 133 "( IC 2010)" . : : : : : noori , . , . , , , . : 35 3(2008.4) GPU Ray Tracing k-D tree (An Efficient k-D tree Traversal Algorithm for Ray Tracing , , , , - Abstract This paper proposes an effective k-D tree traversal algorithm for ray tracing on a GPU

  11. Optimal Pruning for Tree-Structured Vector Quantization.

    ERIC Educational Resources Information Center

    Lin, Jianhua; And Others

    1992-01-01

    Analyzes the computational complexity of optimal binary tree pruning for tree-structured vector quantization. Topics discussed include the combinatorial nature of the optimization problem; the complexity of optimal tree pruning; and finding a minimal size pruned tree. (11 references) (LRW)

  12. Can These Trees Be Saved? Eric L. Taylor, Extension Specialist,

    E-print Network

    ER-039 5-06 Can These Trees Be Saved? Eric L. Taylor, Extension Specialist, and C. Darwin Foster or other disaster can leave trees looking like there's no tomorrow. Ma- jor limbs may be broken or damaged like mortal wounds are not necessarily fatal to a tree. Trees have an amazing ability to re- cover from

  13. Regular networks can be uniquely constructed from their trees

    E-print Network

    Willson, Stephen J.

    1 Regular networks can be uniquely constructed from their trees Stephen J. Willson Department with labelled leaves displays a tree T when there exists a way to select a unique parent of each hybrid vertex resulting in the tree T. Let Tr(N) denote the set of all trees displayed by the network N. In general

  14. 7 CFR 1437.306 - Christmas tree crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop and may generate a claim for benefits under this part only if the tree was grown exclusively...

  15. COMMON TREES ON THE FIU CAMPUS AND IN MIAMI

    E-print Network

    Koptur, Suzanne

    1 COMMON TREES ON THE FIU CAMPUS AND IN MIAMI by David Lee Department of Biological Sciences Campus Map.......................................24 Tree Descriptions.................................27.........................................55 #12;2 FIU TREE PUZZLE INTRODUCTION This key and concise description of common trees will help you

  16. 7 CFR 1437.306 - Christmas tree crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop and may generate a claim for benefits under this part only if the tree was grown exclusively...

  17. 7 CFR 1437.306 - Christmas tree crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop and may generate a claim for benefits under this part only if the tree was grown exclusively...

  18. Dynamic Trees: A Hierarchical Probabilistic Approach to Image Modelling 

    E-print Network

    Adams, Nicholas J.

    This work introduces a new class of image model which we call dynamic trees or DTs. A dynamic tree model specifies a prior over structures of trees, each of which is a forest of one or more tree-structured belief networks ...

  19. 7 CFR 1437.306 - Christmas tree crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop and may generate a claim for benefits under this part only if the tree was grown exclusively...

  20. Dependencies between Shape Parameters in Random Log-Trees

    E-print Network

    Fuchs, Michael

    Dependencies between Shape Parameters in Random Log-Trees (joint with H.-H. Chern, H.-K. Hwang, Taiwan Chennai, July 10, 2015 Michael Fuchs (NCTU) Dependencies in Log-Trees Chennai, July 10, 2015 1 / 31 #12;Random Trees Random Trees Theory Applications Combinatorial Probabilistical Analytical

  1. 7 CFR 1437.306 - Christmas tree crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop and may generate a claim for benefits under this part only if the tree was grown exclusively...

  2. A Statistical Approach to Decision Tree Modeling Michael I. Jordan

    E-print Network

    Jordan, Michael I.

    A Statistical Approach to Decision Tree Modeling Michael I. Jordan Department of Brain A statistical approach to decision tree modeling is described. In this approach, each decision in the tree INTRODUCTION Decision tree algorithms have been studied throughout ma­ chine learning and statistics

  3. OC1: A randomized algorithm for building oblique decision trees

    E-print Network

    Beigel, Richard

    OC1: A randomized algorithm for building oblique decision trees Sreerama K. Murthy Simon Kasif This paper introduces OC1, a new algorithm for generating multivariate decision trees. Multivariate trees. Keywords: decision trees, randomized algorithms, classification, induction #12; 1 Introduction Decision

  4. Exploiting Thread-Level Parallelism to Build Decision Trees

    E-print Network

    Chawla, Nitesh V.

    Exploiting Thread-Level Parallelism to Build Decision Trees Karsten Steinhaeuser, Nitesh V. Chawla task, and decision trees have emerged as a popular classifier due to their simplicity and rela- tively a decision tree still becomes intractable. Hence, there is an increasing need for more efficient tree

  5. CS322 Fall 1999 Module 11 (Decision Tree Learning)

    E-print Network

    Poole, David

    CS322 Fall 1999 Module 11 (Decision Tree Learning) Assignment 11 Solution Question 1 In electronic of the values of the other variables. Suppose we measure the error of a decision tree as the number of misclassified examples. The optimal decision tree from a class of decision trees is an element of the class

  6. Regularizing Soft Decision Trees Olcay Taner Yildiz and Ethem Alpaydin

    E-print Network

    Alpaydýn, Ethem

    Regularizing Soft Decision Trees Olcay Taner Yildiz and Ethem Alpaydin Abstract Recently, we have proposed a new decision tree family called soft decision trees where a node chooses both its left and right novel approach with the standard decision tree algorithms over 27 classification data sets. We see

  7. A Support Vector Machine Approach to Decision Trees

    E-print Network

    Mitchell, John E.

    A Support Vector Machine Approach to Decision Trees K. P. Bennett Mathematical Sciences Department theory and support vector ma­ chines are generalized to decision trees. A support vector machine is used for each decision in the tree. The ``optimal'' decision tree is characterized, and both a primal and dual

  8. Tree detection from aerial imagery Computer and Information Sciences

    E-print Network

    Cortes, Corinna

    ,emilp,xiaoxuma}@google.com ABSTRACT We propose an automatic approach to tree detection from aerial imagery. First a pixelTree detection from aerial imagery Lin Yang Computer and Information Sciences University-level classifier is trained to as- sign a {tree, non-tree} label to each pixel in an aerial image. The pixel

  9. A Parallel Approach to Evidence Combination on Qualitative Markov trees

    E-print Network

    Liu, Weiru

    A Parallel Approach to Evidence Combination on Qualitative Markov trees Xin Hong, Weiru Liu, Kenny. This paper presents a parallel approach to evidence combination on a qualitative Markov tree. Binarization algorithm transforms a qualitative Markov tree into a binary tree based on the computational workload

  10. On the re-rooting invariance property of Levy trees

    E-print Network

    Le Gall, Jean-François

    On the re-rooting invariance property of L´evy trees Thomas Duquesne and Jean-Fran¸cois Le Gall of the continuous random trees called L´evy trees. This extends previous results due to several authors. 1 Introduction Continuous random trees have been studied extensively in the last fifteen years and have found

  11. Multiway trees of maximum and minimum probability under the

    E-print Network

    Dobrow, Bob

    Multiway trees of maximum and minimum probability under the random permutation model [short title: Random multiway trees] by Robert P. Dobrow and James Allen Fill1 Northeast Missouri State University and The Johns Hopkins University Abstract Multiway trees, also known as m-ary search trees, are data struc

  12. Mutually embeddable graphs and the Tree Alternative conjecture

    E-print Network

    Bonato, Anthony

    Mutually embeddable graphs and the Tree Alternative conjecture Anthony Bonato a a Abstract We prove that if a rayless tree T is mutually embeddable and non-isomorphic with another rayless tree, then T is mutually embeddable and non-isomorphic with in- finitely many rayless trees. The proof

  13. Tree Location Wood You Like to Know About the

    E-print Network

    Ashline, George

    Tree Location Wood You Like to Know About the Ginkgo? Leaf Investigation A tree activity for Saplings (Children ages 8-11) Did you know? The Ginkgo tree has been around for 350 million years? The lifespan of a single Ginkgo tree is up to 1,000 years? The Ginkgo's leaves turn bright yellow in autumn

  14. Trees and networks before and after Darwin

    PubMed Central

    2009-01-01

    It is well-known that Charles Darwin sketched abstract trees of relationship in his 1837 notebook, and depicted a tree in the Origin of Species (1859). Here I attempt to place Darwin's trees in historical context. By the mid-Eighteenth century the Great Chain of Being was increasingly seen to be an inadequate description of order in nature, and by about 1780 it had been largely abandoned without a satisfactory alternative having been agreed upon. In 1750 Donati described aquatic and terrestrial organisms as forming a network, and a few years later Buffon depicted a network of genealogical relationships among breeds of dogs. In 1764 Bonnet asked whether the Chain might actually branch at certain points, and in 1766 Pallas proposed that the gradations among organisms resemble a tree with a compound trunk, perhaps not unlike the tree of animal life later depicted by Eichwald. Other trees were presented by Augier in 1801 and by Lamarck in 1809 and 1815, the latter two assuming a transmutation of species over time. Elaborate networks of affinities among plants and among animals were depicted in the late Eighteenth and very early Nineteenth centuries. In the two decades immediately prior to 1837, so-called affinities and/or analogies among organisms were represented by diverse geometric figures. Series of plant and animal fossils in successive geological strata were represented as trees in a popular textbook from 1840, while in 1858 Bronn presented a system of animals, as evidenced by the fossil record, in a form of a tree. Darwin's 1859 tree and its subsequent elaborations by Haeckel came to be accepted in many but not all areas of biological sciences, while network diagrams were used in others. Beginning in the early 1960s trees were inferred from protein and nucleic acid sequences, but networks were re-introduced in the mid-1990s to represent lateral genetic transfer, increasingly regarded as a fundamental mode of evolution at least for bacteria and archaea. In historical context, then, the Network of Life preceded the Tree of Life and might again supersede it. Reviewers This article was reviewed by Eric Bapteste, Patrick Forterre and Dan Graur. PMID:19917100

  15. Parallel object-oriented decision tree system

    DOEpatents

    Kamath; Chandrika (Dublin, CA), Cantu-Paz; Erick (Oakland, CA)

    2006-02-28

    A data mining decision tree system that uncovers patterns, associations, anomalies, and other statistically significant structures in data by reading and displaying data files, extracting relevant features for each of the objects, and using a method of recognizing patterns among the objects based upon object features through a decision tree that reads the data, sorts the data if necessary, determines the best manner to split the data into subsets according to some criterion, and splits the data.

  16. The Lie algebra of rooted planar trees

    E-print Network

    Ishida, Tomohiko

    2011-01-01

    We study a natural Lie algebra structure on the free vector space generated by all rooted planar trees as the associated Lie algebra of the preoperad (non-$\\Sigma$ operad) of rooted planar trees. We determine whether the Lie algebra and some related Lie algebras are finitely generated or not, and prove that a natural surjection called the augmentation homomorphism onto the Lie algebra of polynomial vector fields on the line has no splitting preserving the units.

  17. Fatal head trauma from tree related injuries.

    PubMed

    Escoffery, C T; Shirley, S E

    2001-10-01

    Two cases of death following tree related injuries are presented. Two females, an elderly woman and a child, suffered severe head trauma from falling objects from trees--a falling coconut and a falling branch respectively. Although this mode of injury has been previously documented, there have been no prior reports of in-hospital deaths in such patients. This uncommon cause of death is reviewed and recommendations made concerning its prevention. PMID:11693223

  18. Speeding up Boosting decision trees training

    NASA Astrophysics Data System (ADS)

    Zheng, Chao; Wei, Zhenzhong

    2015-10-01

    To overcome the drawback that Boosting decision trees perform fast speed in the test time while the training process is relatively too slow to meet the requirements of applications with real-time learning, we propose a fast decision trees training method by pruning those noneffective features in advance. And basing on this method, we also design a fast Boosting decision trees training algorithm. Firstly, we analyze the structure of each decision trees node, and prove that the classification error of each node has a bound through derivation. Then, by using the error boundary to prune non-effective features in the early stage, we greatly accelerate the decision tree training process, and would not affect the training results at all. Finally, the decision tree accelerated training method is integrated into the general Boosting process forming a fast boosting decision trees training algorithm. This algorithm is not a new variant of Boosting, on the contrary, it should be used in conjunction with existing Boosting algorithms to achieve more training acceleration. To test the algorithm's speedup performance and performance combined with other accelerated algorithms, the original AdaBoost and two typical acceleration algorithms LazyBoost and StochasticBoost were respectively used in conjunction with this algorithm into three fast versions, and their classification performance was tested by using the Lsis face database which contained 12788 images. Experimental results reveal that this fast algorithm can achieve more than double training speedup without affecting the results of the trained classifier, and can be combined with other acceleration algorithms. Key words: Boosting algorithm, decision trees, classifier training, preliminary classification error, face detection

  19. Whatever happened to whole-tree chipping

    SciTech Connect

    Hills, C.F.

    1980-09-01

    There has been a dramatic increase in the utilization of chipper units since 1975. Continuing and increased demand for fiber indicates harvesting the maximum fiber per acre. Overall the increased yield is in the range of 25-40% and wood-tree chips are being put to a variety of uses. This article reviews the significant developments in both harvesting and mill site equipment which have allowed increased use of whole-tree chips while reducing grit load to the mill system.

  20. TPM: Tree-Particle-Mesh code

    NASA Astrophysics Data System (ADS)

    Bode, Paul

    2013-05-01

    TPM carries out collisionless (dark matter) cosmological N-body simulations, evolving a system of N particles as they move under their mutual gravitational interaction. It combines aspects of both Tree and Particle-Mesh algorithms. After the global PM forces are calculated, spatially distinct regions above a given density contrast are located; the tree code calculates the gravitational interactions inside these denser objects at higher spatial and temporal resolution. The code is parallel and uses MPI for message passing.

  1. Tree Fruit Varieties in North Texas. 

    E-print Network

    Brooks, L. E. (Lester E.)

    1936-01-01

    ~as. --- e Fruit Varieties in North Texas AGRIC~TIJTUBUAIJ AND MECHANICAL COI;LEGE OF TEXAS T. 0. WALTON, President rree fruit varietal investigations were begun at the Wichita Valley Station with the setting of a large number of trees in 1926.... Cherries have proved unadapted, having died from natural causes without fruiting. Peaches and plums are the most dependable tree fruits for this section. The success of either depends to a great extent on the proper selection of varieties...

  2. Intraspecific scaling laws of vascular trees

    PubMed Central

    Huo, Yunlong; Kassab, Ghassan S.

    2012-01-01

    A fundamental physics-based derivation of intraspecific scaling laws of vascular trees has not been previously realized. Here, we provide such a theoretical derivation for the volume–diameter and flow–length scaling laws of intraspecific vascular trees. In conjunction with the minimum energy hypothesis, this formulation also results in diameter–length, flow–diameter and flow–volume scaling laws. The intraspecific scaling predicts the volume–diameter power relation with a theoretical exponent of 3, which is validated by the experimental measurements for the three major coronary arterial trees in swine (where a least-squares fit of these measurements has exponents of 2.96, 3 and 2.98 for the left anterior descending artery, left circumflex artery and right coronary artery trees, respectively). This scaling law as well as others agrees very well with the measured morphometric data of vascular trees in various other organs and species. This study is fundamental to the understanding of morphological and haemodynamic features in a biological vascular tree and has implications for vascular disease. PMID:21676970

  3. A global history of Australian trees.

    PubMed

    Bennett, Brett M

    2011-01-01

    Scholars studying the globalization of Australian trees have previously emphasized the rapid natural propagation of Australian trees outside of their native habitats, believing their success to be a reversal of "ecological imperialism" from the "new world" to the "old world." This article argues that the expansion of Australian trees should not be viewed as a biological phenomenon, but as the result of a long-term attempt by powerful states and state-sponsored scientists to select and breed Australian species that could grow in a variety of climates and ecological conditions. Five non-biological factors largely determined the success of these attempts to grow Australian trees: the abundance or paucity of natural forests, state power, the amount of scientific research directed to planting Australian trees, the cost of labor, and the ability to utilize hardwood timbers and bark. This paper compares the use of Australian trees in Australia, India, and South Africa to demonstrate that biology was not the determining factor in the long-term success of many Australian genera and species. PMID:20665086

  4. A natural history of human tree climbing.

    PubMed

    Kraft, Thomas S; Venkataraman, Vivek V; Dominy, Nathaniel J

    2014-06-01

    Walking and running have dominated the literature on human locomotor evolution at the expense of other behaviors with positive and negative fitness consequences. For example, although modern hunter-gatherers frequently climb trees to obtain important food resources in the canopy, these behaviors are seldom considered within the existing framework of primate positional behavior. As a result, inferences about the arboreal performance capabilities of fossil hominins based on a resemblance to humans may be more complicated than previously assumed. Here we use ethnographic reports of human tree climbing to critically evaluate hypotheses about the performance capabilities of humans in trees compared with other primates. We do so by reviewing the ecological basis of tree climbing behavior among hunter-gatherers and the diversity of human climbing techniques and styles. Results suggest that the biological and adaptive significance of human climbing has been underestimated, and that some humans are surprisingly competent in trees, particularly during vertical climbing and activities in the central core of trees. We conclude that while hominins evolved enhanced terrestrial locomotor performance through time, such shifts may have imposed only minor costs on vertical climbing abilities. The diversity of the locomotor repertoire of modern humans must therefore be taken into account when making form-function inferences during the behavioral reconstruction of fossil hominins. PMID:24630525

  5. ANTLR Tree Grammar Generator and Extensions

    NASA Technical Reports Server (NTRS)

    Craymer, Loring

    2005-01-01

    A computer program implements two extensions of ANTLR (Another Tool for Language Recognition), which is a set of software tools for translating source codes between different computing languages. ANTLR supports predicated- LL(k) lexer and parser grammars, a notation for annotating parser grammars to direct tree construction, and predicated tree grammars. [ LL(k) signifies left-right, leftmost derivation with k tokens of look-ahead, referring to certain characteristics of a grammar.] One of the extensions is a syntax for tree transformations. The other extension is the generation of tree grammars from annotated parser or input tree grammars. These extensions can simplify the process of generating source-to-source language translators and they make possible an approach, called "polyphase parsing," to translation between computing languages. The typical approach to translator development is to identify high-level semantic constructs such as "expressions," "declarations," and "definitions" as fundamental building blocks in the grammar specification used for language recognition. The polyphase approach is to lump ambiguous syntactic constructs during parsing and then disambiguate the alternatives in subsequent tree transformation passes. Polyphase parsing is believed to be useful for generating efficient recognizers for C++ and other languages that, like C++, have significant ambiguities.

  6. Two Step Decision Tree for Polymer Discrimination

    NASA Astrophysics Data System (ADS)

    Otani, Noriko; Kaihara, Mikio; Shimura, Masamichi

    This paper proposes a novel method for generating a decision tree to discriminate polymers accurately with the near-infrared rays spectrum. The polymer discrimination system is needed for recycling plastics, and the near-infrared rays spectrum is useful for rapid and non-destructive discrimination. The former system SESAT, which is based on symbiotic evolution, can generate simple and accurate trees, but is not effective for data that has a lot of attributes like the near-infrared rays spectrum. We design the structure of the partial solution ``sprig'' for sufficient learning, and the fitness function of the whole solution ``decision tree blueprint'' for 2-class discrimination. In addition, we introduce two-step discrimination with the aim of obtaining higher accuracy. In the first step, examples are divided into two groups, one group being easier than the other to discriminate by a tree. In the second step, two trees are generated that discriminate one kind of polymer from the others, for two groups of examples. By doing this, a minority of examples is also discriminated accurately. Based on this method we developed a polymer discrimination system called TS-SEPT. Our experimental results on real data of polymers show that the accuracy of TS-SEPT compares favorably with that of the other systems, the similar system without two-step discrimination, SESAT and C5.0. It emerged that both the method for generating decision trees and two-step discrimination contributed to the improved accuracy.

  7. GRADE 11 UP WITH SCIENCE PROGRAMME 2014 Prepared by Khumbuzile Bophela and Amy Wooding

    E-print Network

    isolated from the samples by plating them out on two types of media; MEA to culture to fungi, and LB on the health of the Jacaranda trees in Pretoria, which has been a hot topic in the media in the past year to culture bacteria. The learners were exposed to various subculturing methods including single mycelium

  8. TreeRipper web application: towards a fully automated optical tree recognition software

    PubMed Central

    2011-01-01

    Background Relationships between species, genes and genomes have been printed as trees for over a century. Whilst this may have been the best format for exchanging and sharing phylogenetic hypotheses during the 20th century, the worldwide web now provides faster and automated ways of transferring and sharing phylogenetic knowledge. However, novel software is needed to defrost these published phylogenies for the 21st century. Results TreeRipper is a simple website for the fully-automated recognition of multifurcating phylogenetic trees (http://linnaeus.zoology.gla.ac.uk/~jhughes/treeripper/). The program accepts a range of input image formats (PNG, JPG/JPEG or GIF). The underlying command line c++ program follows a number of cleaning steps to detect lines, remove node labels, patch-up broken lines and corners and detect line edges. The edge contour is then determined to detect the branch length, tip label positions and the topology of the tree. Optical Character Recognition (OCR) is used to convert the tip labels into text with the freely available tesseract-ocr software. 32% of images meeting the prerequisites for TreeRipper were successfully recognised, the largest tree had 115 leaves. Conclusions Despite the diversity of ways phylogenies have been illustrated making the design of a fully automated tree recognition software difficult, TreeRipper is a step towards automating the digitization of past phylogenies. We also provide a dataset of 100 tree images and associated tree files for training and/or benchmarking future software. TreeRipper is an open source project licensed under the GNU General Public Licence v3. PMID:21599881

  9. Fault tree analysis for maintenance needs

    NASA Astrophysics Data System (ADS)

    Halme, Jari; Aikala, Antti

    2012-05-01

    One of the key issues in maintenance is to allocate focus and resources to those components and subsystems which are the most unreliable and prone to failures. In industrial systems, fault tree analysis technique can be used to study the reliability of the complex systems and their substructures. In this paper a fault tree application for analyzing online the current reliability and failure probability for maintenance purposes is presented. The analysis is utilizing data connected to the fault tree root causes and events. An indication of an anomaly case, service action, cumulative loading, etc., or just time passed or service hour counter level can trigger a new calculation of current probabilities of the fault tree events and subsystem interactions. In proposed approach real time, dynamic information from several available data sources and different measurement are interconnected to each fault tree event and root cause. There is also formulated an active, constantly updated link between the fault tree events and maintenance databases for the maintenance decision support, and to keep the analysis up to date. Typically top event probability is evaluated based on updated root cause probabilities and lower level events. At the industrial plant level an identification of a failure in a component event defined within a constructed and operatively existing fault tree explicitly means that the event's failure probability is one. By utilizing this indication, the most probable failure branches through the fault tree sub events to root causes can be identified and printed as a valid check list for maintenance purposes to focus service actions first to those fault tree branches most probable causing the failure. Respectively, during the checks, service actions, etc., components, especially those within the critical branches, detected as healthy can be a updated as having zero failure probability. This information can be used to further update the fault tree and produce online a new service order list. The added value of the proposed method with respect to developed software platform functions lies in its applicability to rationalize maintenance actions and in a case of a failure allocate resources where they are assumable mostly needed.

  10. Temperature histories from tree rings and corals

    SciTech Connect

    Cook, E.R.

    1995-05-01

    Recent temperature trends in long tree-ring and coral proxy temperature histories are evaluated and compared in an effort to objectively determine how anomalous twentieth century temperature changes have been. These histories mostly reflect regional variations in summer warmth from the tree rings and annual warmth from the corals. In the Northern Hemisphere. the North American tree-ring temperature histories and those from the north Polar Urals, covering the past 1000 or more years, indicate that the twentieth century has been anomalously warm relative to the past. In contrast, the tree-ring history from northern Fennoscandia indicates that summer temperatures during the {open_quote}Medieval Warm Period{close_quote} were probably warmer on average than those than during this century. In the Southern Hemisphere, the tree-ring temperature histories from South America show no indication of recent warming, which is in accordance with local instrumental records. In contrast, the tree-ring, records from Tasmania and New Zealand indicate that the twentieth century has been unusually warm particularly since 1960. The coral temperature histories from the Galapagos Islands and the Great Barrier Reef are in broad agreement with the tree-ring temperature histories in those sectors, with the former showing recent cooling and the latter showing recent warming that may be unprecedented. Overall, the regional temperature histories evaluated here broadly support the larger-scale evidence for anomalous twentieth century warming based on instrumental records. However, this warming cannot be confirmed as an unprecedented event in all regions. 38 refs., 3 figs., 2 tabs.

  11. Radiocarbon in Tree STEM CO2 Efflux

    NASA Astrophysics Data System (ADS)

    Muhr, J.; Czimczik, C. I.; Angert, A.; Trumbore, S.

    2011-12-01

    Carbon dioxide efflux from tree stems can be a significant component of the stand-level carbon balance. Recent studies have demonstrated that tree stem CO2 efflux may reflect more than just in-situ respiration but also transport from other locations and it has been suggested that it may also include C originally respired in roots or even uptake of soil CO2. We report measurements of the radiocarbon signature of carbon emitted from a range of mature tree stems in tropical and temperate forest ecosystems. Comparison of the radiocarbon signature of respired CO2 with the observed rate of decline in atmsopheric 14C-CO2 provides a measure of the time elapsed between C fixation by the plant and its return to the atmosphere as stem CO2 efflux. In all investigated trees, we observed that stem CO2 efflux had higher radiocarbon signatures than the contemporary atmospheric 14C-CO2, and therefore was derived from C fixed one to several years earlier. In tropical forest trees, we found that the 14C signature of CO2 within the stem (~4-5 cm depth) had even higher radiocarbon signatures than the stem CO2 efflux. In one of the investigated tree species, the in-stem CO2 was derived from C sources fixed on average ~20 years previously. These results confirm observations of root-respired CO2 that also have shown contributions of C substrates older than recent photosynthetic products, and the presence of extracable C reserves in wood that reflect the presence of older C sources. Our results imply that stem CO2 efflux is not only derived from respiration of recent photosynthetic products but includes contributions from older, stored C pools. Ongoing investigations will enable us to compare CO2 efflux for trees subjected to experimental drought, and using different life strategies (deciduous versus evergreen oaks) to determine if the use of these older C stores varies with stress.

  12. Up in the Tree – The Overlooked Richness of Bryophytes and Lichens in Tree Crowns

    PubMed Central

    Boch, Steffen; Müller, Jörg; Prati, Daniel; Blaser, Stefan; Fischer, Markus

    2013-01-01

    Assessing diversity is among the major tasks in ecology and conservation science. In ecological and conservation studies, epiphytic cryptogams are usually sampled up to accessible heights in forests. Thus, their diversity, especially of canopy specialists, likely is underestimated. If the proportion of those species differs among forest types, plot-based diversity assessments are biased and may result in misleading conservation recommendations. We sampled bryophytes and lichens in 30 forest plots of 20 m × 20 m in three German regions, considering all substrates, and including epiphytic litter fall. First, the sampling of epiphytic species was restricted to the lower 2 m of trees and shrubs. Then, on one representative tree per plot, we additionally recorded epiphytic species in the crown, using tree climbing techniques. Per tree, on average 54% of lichen and 20% of bryophyte species were overlooked if the crown was not been included. After sampling all substrates per plot, including the bark of all shrubs and trees, still 38% of the lichen and 4% of the bryophyte species were overlooked if the tree crown of the sampled tree was not included. The number of overlooked lichen species varied strongly among regions. Furthermore, the number of overlooked bryophyte and lichen species per plot was higher in European beech than in coniferous stands and increased with increasing diameter at breast height of the sampled tree. Thus, our results indicate a bias of comparative studies which might have led to misleading conservation recommendations of plot-based diversity assessments. PMID:24358373

  13. "Trees and Things That Live in Trees": Three Children with Special Needs Experience the Project Approach

    ERIC Educational Resources Information Center

    Griebling, Susan; Elgas, Peg; Konerman, Rachel

    2015-01-01

    The authors report on research conducted during a project investigation undertaken with preschool children, ages 3-5. The report focuses on three children with special needs and the positive outcomes for each child as they engaged in the project Trees and Things That Live in Trees. Two of the children were diagnosed with developmental delays, and…

  14. Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees.

    PubMed

    Pflug, Ellen E; Siegwolf, R; Buchmann, N; Dobbertin, M; Kuster, T M; Günthardt-Goerg, M S; Arend, M

    2015-10-01

    An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (?(13)C and ?(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased ?(18)O and ?(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in ?(18)O, was observed in tree rings but not in leaves. This decrease in ?(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses. PMID:26377873

  15. GM trees with increased resistance to herbivores: trait efficiency and their potential to promote tree growth

    PubMed Central

    Hjältén, Joakim; Axelsson, E. Petter

    2015-01-01

    Climate change, as well as a more intensive forestry, is expected to increase the risk of damage by pests and pathogens on trees, which can already be a severe problem in tree plantations. Recent development of biotechnology theoretically allows for resistance enhancement that could help reduce these risks but we still lack a comprehensive understanding of benefits and tradeoffs with pest resistant GM (genetically modified) trees. We synthesized the current knowledge on the effectiveness of GM forest trees with increased resistance to herbivores. There is ample evidence that induction of exogenous Bacillus thuringiensis genes reduce performance of target pests whereas upregulation of endogenous resistance traits e.g., phenolics, generates variable results. Our review identified very few studies estimating the realized benefits in tree growth of GM trees in the field. This is concerning as the realized benefit with insect resistant GM plants seems to be context-dependent and likely manifested only if herbivore pressure is sufficiently high. Future studies of secondary pest species and resistance evolution in pest to GM trees should be prioritized. But most importantly we need more long-term field tests to evaluate the benefits and risks with pest resistant GM trees. PMID:25983736

  16. Chapter 4. Trees 4.1 Basic concepts (Section 4.1)

    E-print Network

    Wu, Xindong

    : Weiss 4 #12;3 Tree taxonomy From the general to the specific: 1. Free tree: no root; looks like a spanning tree of a graph 2. Unordered tree: has the root; no order among children. 3. Ordered tree: has the root; ordering among children. What we mean by "tree" here. 4. M-ary tree: number of child nodes M 5

  17. 6. Binary search trees David Keil Data Structures Spring 2015 David Keil Data Structures 6. Binary search trees Spring 2015 1

    E-print Network

    Keil, David M.

    6. Binary search trees David Keil Data Structures Spring 2015 David Keil Data Structures 6. Binary search trees Spring 2015 1 David M. Keil, Framingham State University CSCI 271 Data Structures 6. Binary search trees 1. Binary search trees 2. Insertion and deletion 3. Tree balancing 4. B trees and tries

  18. Global tree network for computing structures enabling global processing operations

    DOEpatents

    Blumrich; Matthias A. (Ridgefield, CT); Chen, Dong (Croton-On-Hudson, NY); Coteus, Paul W. (Yorktown Heights, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk (Ossining, NY); Steinmacher-Burow, Burkhard D. (Mount Kisco, NY); Takken, Todd E. (Mount Kisco, NY); Vranas, Pavlos M. (Bedford Hills, NY)

    2010-01-19

    A system and method for enabling high-speed, low-latency global tree network communications among processing nodes interconnected according to a tree network structure. The global tree network enables collective reduction operations to be performed during parallel algorithm operations executing in a computer structure having a plurality of the interconnected processing nodes. Router devices are included that interconnect the nodes of the tree via links to facilitate performance of low-latency global processing operations at nodes of the virtual tree and sub-tree structures. The global operations performed include one or more of: broadcast operations downstream from a root node to leaf nodes of a virtual tree, reduction operations upstream from leaf nodes to the root node in the virtual tree, and point-to-point message passing from any node to the root node. The global tree network is configurable to provide global barrier and interrupt functionality in asynchronous or synchronized manner, and, is physically and logically partitionable.

  19. Parallel search of strongly ordered game trees

    SciTech Connect

    Marsland, T.A.; Campbell, M.

    1982-12-01

    The alpha-beta algorithm forms the basis of many programs that search game trees. A number of methods have been designed to improve the utility of the sequential version of this algorithm, especially for use in game-playing programs. These enhancements are based on the observation that alpha beta is most effective when the best move in each position is considered early in the search. Trees that have this so-called strong ordering property are not only of practical importance but possess characteristics that can be exploited in both sequential and parallel environments. This paper draws upon experiences gained during the development of programs which search chess game trees. Over the past decade major enhancements of the alpha beta algorithm have been developed by people building game-playing programs, and many of these methods will be surveyed and compared here. The balance of the paper contains a study of contemporary methods for searching chess game trees in parallel, using an arbitrary number of independent processors. To make efficient use of these processors, one must have a clear understanding of the basic properties of the trees actually traversed when alpha-beta cutoffs occur. This paper provides such insights and concludes with a brief description of a refinement to a standard parallel search algorithm for this problem. 33 references.

  20. 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.

  1. Generating Dark Matter Halo Merger Trees

    E-print Network

    Hannah Parkinson; Shaun Cole; John Helly

    2007-11-22

    We present a new Monte-Carlo algorithm to generate merger trees describing the formation history of dark matter halos. The algorithm is a modification of the algorithm of Cole et al (2000) used in the GALFORM semi-analytic galaxy formation model. As such, it is based on the Extended Press-Schechter theory and so should be applicable to hierarchical models with a wide range of power spectra and cosmological models. It is tuned to be in accurate agreement with the conditional mass functions found in the analysis of merger trees extracted from the LCDM Millennium N-body simulation. We present a comparison of its predictions not only with these conditional mass functions, but also with additional statistics of the Millennium Simulation halo merger histories. In all cases we find it to be in good agreement with the Millennium Simulation and thus it should prove to be a very useful tool for semi-analytic models of galaxy formation and for modelling hierarchical structure formation in general. We have made our merger tree generation code and code to navigate the trees available at http://star-www.dur.ac.uk/~cole/merger_trees .

  2. Jump processes on leaves of multibranching trees

    E-print Network

    Sergio Albeverio; Witold Karwowski

    2008-04-26

    The p-adic numbers have found applications in a wide range of diverse fields of research. In some applications the algebraic properties of p-adics enter as an indispensable ingredient of the theory. Another class of applications has to do with hierarchical tree like systems. In this context the applications are based on the well known correspondence between p-adics and the trees with p-branches emerging from every branching point. Then the algebraic structure does not enter and p-adics are used merely as a labeling system for the tree branches. We introduce a space of numerical sequences suitable for labeling the trees with varying number of branches emerging from the branching points. We equipe this space with a non Archimedian metric and describe its basic topological properties. We also demonstrate that the known construction of the stochastic processes on p-adics carry over to the stochastic processes on the above mentioned space and hence on the corresponding trees.

  3. Phillips goes subsea trees in Ivory Coast

    SciTech Connect

    Bryngelson, R.H.

    1982-11-15

    Describes installation of 3 satellite subsea trees in 500 ft of water from a semisubmersible drilling rig. These wet, diver-assist trees are part of Phillips Petroleum's early development and production program (EDPP) for the Espoir field offshore Ivory Coast, with plans calling for 5 satellite wells with downhole completion equipment and subsea production trees. Diagram shows how a converted jackup, Dan Duke, supports equipment to handle production from subsea wells. Table gives time breakdown of subsea tree installation. Before mobilizing the subsea trees, control system, and tubulars to the rig, a study of deck layout, payloads, and traffic patterns was performed. Concludes that, based on experience in this project and the cost differences between purchase and installation costs, final success is 90% dependent on informed and trained field personnel after engineering, design, and manufacturing; attention to installation procedures and training of field and operational personnel are as critical or more critical than design changes to equipment; and selection of a supplier for high technology equipment, based on a low bid alone, may not translate into lower installation costs.

  4. How tree roots respond to drought

    PubMed Central

    Brunner, Ivano; Herzog, Claude; Dawes, Melissa A.; Arend, Matthias; Sperisen, Christoph

    2015-01-01

    The ongoing climate change is characterized by increased temperatures and altered precipitation patterns. In addition, there has been an increase in both the frequency and intensity of extreme climatic events such as drought. Episodes of drought induce a series of interconnected effects, all of which have the potential to alter the carbon balance of forest ecosystems profoundly at different scales of plant organization and ecosystem functioning. During recent years, considerable progress has been made in the understanding of how aboveground parts of trees respond to drought and how these responses affect carbon assimilation. In contrast, processes of belowground parts are relatively underrepresented in research on climate change. In this review, we describe current knowledge about responses of tree roots to drought. Tree roots are capable of responding to drought through a variety of strategies that enable them to avoid and tolerate stress. Responses include root biomass adjustments, anatomical alterations, and physiological acclimations. The molecular mechanisms underlying these responses are characterized to some extent, and involve stress signaling and the induction of numerous genes, leading to the activation of tolerance pathways. In addition, mycorrhizas seem to play important protective roles. The current knowledge compiled in this review supports the view that tree roots are well equipped to withstand drought situations and maintain morphological and physiological functions as long as possible. Further, the reviewed literature demonstrates the important role of tree roots in the functioning of forest ecosystems and highlights the need for more research in this emerging field. PMID:26284083

  5. Tree-mediated methane emissions from tropical and temperate peatlands.

    NASA Astrophysics Data System (ADS)

    Pangala, S. R.; Gauci, V.; Hornibrook, E. R. C.; Gowing, D. J.

    2012-04-01

    Methane production and transport processes in peatlands are fairly well understood, but growing evidence for emission of methane through trees has highlighted the need to revisit methane transport processes. In wetland trees, morphological adaptations such as development of hypertrophied lenticels, aerenchyma and adventitious roots in response to soil anoxia mediates gas transport, transporting both oxygen from the atmosphere to oxygen-deprived roots and soil-produced methane from the root-zone to the atmosphere. Although, tree-mediated methane emissions from temperate tree species have been confirmed, methane emissions from tropical tree species and processes that control tree-mediated methane emissions remain unclear. This study explains the role of trees in transporting soil-produced methane to the atmosphere and uncovers the principal mechanisms of tree-mediated methane emissions. Methane emissions from eight tropical tree species and two temperate tree species were studied in situ. The mechanisms and controls on tree-mediated methane emissions were investigated using three year old common alder (Alnus glutinosa; 50 trees) grown under two artificially controlled water-table positions. Methane fluxes from whole mesocosms, the soil surface and tree stems were measured using static closed chambers. Both temperate and tropical tree species released significant quantities of methane, with tropical trees dominating ecosystem level methane fluxes. In temperate peatlands, both the methane gas transport mechanism and quantity of methane emitted from stems is tree-species dependent. In Alnus glutinosa, no correlations were observed between stomatal behaviour and tree-mediated methane emissions, however, stem methane emissions were positively correlated with both stem lenticel density and dissolved soil methane concentration. In Alnus glutinosa, no emissions were observed from leaf surfaces. The results demonstrate that exclusion of tree-mediated methane emissions from flux measurement campaigns in forested peatlands will lead to an underestimation of ecosystem-wide methane emissions.

  6. From quantum electrodynamics to posets of planar binary trees

    E-print Network

    Frédéric Chapoton; Alessandra Frabetti

    2008-11-28

    This paper is a brief mathematical excursion which starts from quantum electrodynamics and leads to the Moebius function of the Tamari lattice of planar binary trees, within the framework of groups of tree-expanded series. First we recall Brouder's expansion of the photon and the electron Green's functions on planar binary trees, before and after the renormalization. Then we recall the structure of Connes and Kreimer's Hopf algebra of renormalization in the context of planar binary trees, and of their dual group of tree-expanded series. Finally we show that the Moebius function of the Tamari posets of planar binary trees gives rise to a particular series in this group.

  7. Forward estimation for game-tree search

    SciTech Connect

    Zhang, Weixiong

    1996-12-31

    It is known that bounds on the minimax values of nodes in a game tree can be used to reduce the computational complexity of minimax search for two-player games. We describe a very simple method to estimate bounds on the minimax values of interior nodes of a game tree, and use the bounds to improve minimax search. The new algorithm, called forward estimation, does not require additional domain knowledge other than a static node evaluation function, and has small constant overhead per node expansion. We also propose a variation of forward estimation, which provides a tradeoff between computational complexity and decision quality. Our experimental results show that forward estimation outperforms alpha-beta pruning on random game trees and the game of Othello.

  8. Tree attenuation at 20 GHz: Foliage effects

    NASA Technical Reports Server (NTRS)

    Vogel, Wolfhard J.; Goldhirsh, Julius

    1993-01-01

    Static tree attenuation measurements at 20 GHz (K-Band) on a 30 deg slant path through a mature Pecan tree with and without leaves showed median fades exceeding approximately 23 dB and 7 dB, respectively. The corresponding 1% probability fades were 43 dB and 25 dB. Previous 1.6 GHz (L-Band) measurements for the bare tree case showed fades larger than those at K-Band by 3.4 dB for the median and smaller by approximately 7 dB at the 1% probability. While the presence of foliage had only a small effect on fading at L-Band (approximately 1 dB additional for the median to 1% probability range), the attenuation increase was significant at K-Band, where it increased by about 17 dB over the same probability range.

  9. Tree attenuation at 20 GHz: Foliage effects

    NASA Astrophysics Data System (ADS)

    Vogel, Wolfhard J.; Goldhirsh, Julius

    1993-08-01

    Static tree attenuation measurements at 20 GHz (K-Band) on a 30 deg slant path through a mature Pecan tree with and without leaves showed median fades exceeding approximately 23 dB and 7 dB, respectively. The corresponding 1% probability fades were 43 dB and 25 dB. Previous 1.6 GHz (L-Band) measurements for the bare tree case showed fades larger than those at K-Band by 3.4 dB for the median and smaller by approximately 7 dB at the 1% probability. While the presence of foliage had only a small effect on fading at L-Band (approximately 1 dB additional for the median to 1% probability range), the attenuation increase was significant at K-Band, where it increased by about 17 dB over the same probability range.

  10. Wind training in some prairie trees

    USGS Publications Warehouse

    Bogan, M.A.; Mollhagen, T.R.

    1969-01-01

    Asymmetry in tree crowns has been established for some time. Lawrence (Ecol. Monogr. 9:217-257, 1939) studied wind training, one cause of asymmetry, in the Columbia River Gorge. He and Boyce (Ecol. Monogr. 24: 29-67, 1954) cite the intensity and direction of wind during the growing season as the causative agents. In their study of trunk asymmetry, Potter and Green (Cology 45: 10-23, 1964) mention crown deformity in the open stands of trees. Prairie trees are typically found in open stands, and to our knowledge no quantitative studies have been done on their crown asymmetry. The present study on the nature of this asymmetry, is an attempt to fill the void.

  11. Performance Characteristics of TreePM codes

    E-print Network

    J. S. Bagla; Suryadeep Ray

    2002-12-05

    We present a detailed analysis of the error budget for the TreePM method for doing cosmological N-Body simulations. It is shown that the choice of filter for splitting the inverse square force into short and long range components suggested in Bagla (2002) is close to optimum. We show that the error in the long range component of the force contributes very little to the total error in force. Errors introduced by the tree approximation for the short range force are different from those for the inverse square force, and these errors dominate the total error in force. We calculate the distribution function for error in force for clustered and unclustered particle distributions. This gives an idea of the error in realistic situations for different choices of parameters of the TreePM algorithm. We test the code by simulating a few power law models and checking for scale invariance.

  12. Arthropod but Not Bird Predation in Ethiopian Homegardens Is Higher in Tree-Poor than in Tree-Rich Landscapes

    PubMed Central

    Lemessa, Debissa; Hambäck, Peter A.; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7–9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  13. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    PubMed

    Lemessa, Debissa; Hambäck, Peter A; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  14. Phenology of temperate trees in tropical climates

    NASA Astrophysics Data System (ADS)

    Borchert, Rolf; Robertson, Kevin; Schwartz, Mark D.; Williams-Linera, Guadalupe

    2005-09-01

    Several North American broad-leaved tree species range from the northern United States at ˜47°N to moist tropical montane forests in Mexico and Central America at 15-20°N. Along this gradient the average minimum temperatures of the coldest month (T Jan), which characterize annual variation in temperature, increase from -10 to 12°C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45°N, the time of bud break is highly correlated with T Jan and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7°C. Temperature-dependent deciduous phenology—and hence the validity of temperature-driven phenology models—terminates in southern North America near 30°N, where T Jan>7°C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.

  15. Autumn frost hardiness in Norway spruce plus tree progeny and trees of the local and transferred provenances in central Sweden.

    PubMed

    Hannerz, Mats; Westin, Johan

    2005-09-01

    Reforestation with provenances from locations remote from the planting site (transferred provenances) or the progeny of trees of local provenances selected for superior form and vigor (plus trees) offer alternative means to increase yield over that obtained by the use of seed from unselected trees of the local provenance. Under Swedish conditions, Norway spruce (Picea abies (L.) Karst.) of certain transferred provenances generally has an advantage in productivity relative to the local provenance comparable to that of progeny of plus trees. The aim of this study was to explore the extent to which productivity gains achieved by provenance transfer or the use of plus tree progeny are associated with reductions in autumn frost hardiness, relative to that of trees of the local provenance. In a field trial with 19-year-old trees in central Sweden, bud hardiness was tested on four occasions during the autumn of 2002. Trees of the local provenance were compared with trees of a south Swedish provenance originating 3 degrees of latitude to the south, a Belarusian provenance and the progeny of plus trees of local origin. The Belarusian provenance was the least hardy and the local provenance the most hardy, with plus tree progeny and the south Swedish provenance being intermediate in hardiness. Both the Belarusian provenance and the plus tree progeny were significantly taller than trees of the other populations. Within provenances, tree height was negatively correlated with autumn frost hardiness. Among the plus tree progeny, however, no such correlation between tree height and autumn frost hardiness was found. It is concluded that although the gain in productivity achieved by provenance transfer from Belarus was comparable to that achieved by using the progeny of plus trees of the local provenance, the use of trees of the Belarus provenance involved an increased risk of autumn frost damage because of later hardening. PMID:15996961

  16. Genome-Scale Phylogenetics: Inferring the Plant Tree of Life from 18,896 Gene Trees

    PubMed Central

    Burleigh, J. Gordon; Bansal, Mukul S.; Eulenstein, Oliver; Hartmann, Stefanie; Wehe, André; Vision, Todd J.

    2011-01-01

    Phylogenetic analyses using genome-scale data sets must confront incongruence among gene trees, which in plants is exacerbated by frequent gene duplications and losses. Gene tree parsimony (GTP) is a phylogenetic optimization criterion in which a species tree that minimizes the number of gene duplications induced among a set of gene trees is selected. The run time performance of previous implementations has limited its use on large-scale data sets. We used new software that incorporates recent algorithmic advances to examine the performance of GTP on a plant data set consisting of 18,896 gene trees containing 510,922 protein sequences from 136 plant taxa (giving a combined alignment length of >2.9 million characters). The relationships inferred from the GTP analysis were largely consistent with previous large-scale studies of backbone plant phylogeny and resolved some controversial nodes. The placement of taxa that were present in few gene trees generally varied the most among GTP bootstrap replicates. Excluding these taxa either before or after the GTP analysis revealed high levels of phylogenetic support across plants. The analyses supported magnoliids sister to a eudicot + monocot clade and did not support the eurosid I and II clades. This study presents a nuclear genomic perspective on the broad-scale phylogenic relationships among plants, and it demonstrates that nuclear genes with a history of duplication and loss can be phylogenetically informative for resolving the plant tree of life. PMID:21186249

  17. Confirmatory Tree Sampling for Tritium in Trees at the Salmon Site, Mississippi

    SciTech Connect

    2010-06-01

    The sampling was conducted on April 20, 21, and 22, 2010. DOE acquired 36 samples for analysis, approximately 10 percent of the total number of samples the Mississippi Forestry Commission acquired. The plan was to sample trees that the Mississippi Forestry Commission also sampled, so that a tree-by-tree comparison of analysis results could be made. The Mississippi Forestry Commission provided DOE with latitude and longitude coordinates, determined by a global positioning system (GPS), for each sampled tree. The Mississippi Forestry Commission also placed a blaze-orange number on each sampled tree. DOE used a GPS unit to assist in locating trees for sampling. DOE acquired one sample from an off-site location to have a reference for comparison to on-site results if necessary. The other 35 samples were acquired on site, for a total of 36 samples. Figure 1 shows the sampling locations, the sample identifiers DOE assigned, and the corresponding tree numbers the Mississippi Forestry Commission assigned

  18. Decision Tree Approach for Soil Liquefaction Assessment

    PubMed Central

    Gandomi, Amir H.; Fridline, Mark M.; Roke, David A.

    2013-01-01

    In the current study, the performances of some decision tree (DT) techniques are evaluated for postearthquake soil liquefaction assessment. A database containing 620 records of seismic parameters and soil properties is used in this study. Three decision tree techniques are used here in two different ways, considering statistical and engineering points of view, to develop decision rules. The DT results are compared to the logistic regression (LR) model. The results of this study indicate that the DTs not only successfully predict liquefaction but they can also outperform the LR model. The best DT models are interpreted and evaluated based on an engineering point of view. PMID:24489498

  19. Livermore Big Trees Park: 1998 Results

    SciTech Connect

    Mac Queen, D; Gallegos, G; Surano, K

    2002-04-18

    This report is an in-depth study of results from environmental sampling conducted in 1998 by the Lawrence Livermore National Laboratory (LLNL) at Big Trees Park in the city of Livermore. The purpose of the sampling was to determine the extent and origin of plutonium found in soil at concentrations above fallout-background levels in the park. This report describes the sampling that was conducted, the chemical and radio-chemical analyses of the samples, the quality control assessments and statistical analyses of the analytical results, and LLNL's interpretations of the results. It includes a number of data analyses not presented in LLNL's previous reports on Big Trees Park.

  20. A survey of decision tree classifier methodology

    NASA Technical Reports Server (NTRS)

    Safavian, S. Rasoul; Landgrebe, David

    1990-01-01

    Decision Tree Classifiers (DTC's) are used successfully in many diverse areas such as radar signal classification, character recognition, remote sensing, medical diagnosis, expert systems, and speech recognition. Perhaps, the most important feature of DTC's is their capability to break down a complex decision-making process into a collection of simpler decisions, thus providing a solution which is often easier to interpret. A survey of current methods is presented for DTC designs and the various existing issue. After considering potential advantages of DTC's over single stage classifiers, subjects of tree structure design, feature selection at each internal node, and decision and search strategies are discussed.

  1. Glued trees algorithm under phase damping

    E-print Network

    J. Lockhart; C. Di Franco; M. Paternostro

    2014-01-04

    We study the behaviour of the glued trees algorithm described by Childs et al. in [STOC `03, Proc. 35th ACM Symposium on Theory of Computing (2004) 59] under decoherence. We consider a discrete time reformulation of the continuous time quantum walk protocol and apply a phase damping channel to the coin state, investigating the effect of such a mechanism on the probability of the walker appearing on the target vertex of the graph. We pay particular attention to any potential advantage coming from the use of weak decoherence for the spreading of the walk across the glued trees graph.

  2. Maximum likelihood clustering with dependent feature trees

    NASA Technical Reports Server (NTRS)

    Chittineni, C. B. (principal investigator)

    1981-01-01

    The decomposition of mixture density of the data into its normal component densities is considered. The densities are approximated with first order dependent feature trees using criteria of mutual information and distance measures. Expressions are presented for the criteria when the densities are Gaussian. By defining different typs of nodes in a general dependent feature tree, maximum likelihood equations are developed for the estimation of parameters using fixed point iterations. The field structure of the data is also taken into account in developing maximum likelihood equations. Experimental results from the processing of remotely sensed multispectral scanner imagery data are included.

  3. A survey of decision tree classifier methodology

    NASA Technical Reports Server (NTRS)

    Safavian, S. R.; Landgrebe, David

    1991-01-01

    Decision tree classifiers (DTCs) are used successfully in many diverse areas such as radar signal classification, character recognition, remote sensing, medical diagnosis, expert systems, and speech recognition. Perhaps the most important feature of DTCs is their capability to break down a complex decision-making process into a collection of simpler decisions, thus providing a solution which is often easier to interpret. A survey of current methods is presented for DTC designs and the various existing issues. After considering potential advantages of DTCs over single-state classifiers, subjects of tree structure design, feature selection at each internal node, and decision and search strategies are discussed.

  4. Disordered Systems, Spanning Trees and SLE

    E-print Network

    Davide Fichera

    2007-09-18

    We define a minimization problem for paths on planar graphs that, on the honeycomb lattice, is equivalent to the exploration path of the critical site percolation and than has the same scaling limit of SLE_6. We numerically study this model (testing several SLE properties on other lattices and with different boundary conditions) and state it in terms of spanning trees. This statement of the problem allows the definition of a random growth process for trees on two dimensional graphs such that SLE is recovered as a special choice of boundary conditions.

  5. How eco-evolutionary principles can guide tree breeding and tree biotechnology for enhanced productivity.

    PubMed

    Franklin, Oskar; Palmroth, Sari; Näsholm, Torgny

    2014-11-01

    Tree breeding and biotechnology can enhance forest productivity and help alleviate the rising pressure on forests from climate change and human exploitation. While many physiological processes and genes are targeted in search of genetically improved tree productivity, an overarching principle to guide this search is missing. Here, we propose a method to identify the traits that can be modified to enhance productivity, based on the differences between trees shaped by natural selection and 'improved' trees with traits optimized for productivity. We developed a tractable model of plant growth and survival to explore such potential modifications under a range of environmental conditions, from non-water limited to severely drought-limited sites. We show how key traits are controlled by a trade-off between productivity and survival, and that productivity can be increased at the expense of long-term survival by reducing isohydric behavior (stomatal regulation of leaf water potential) and allocation to defense against pests compared with native trees. In contrast, at dry sites occupied by naturally drought-resistant trees, the model suggests a better strategy may be to select trees with slightly lower wood density than the native trees and to augment isohydric behavior and allocation to defense. Thus, which traits to modify, and in which direction, depend on the original tree species or genotype, the growth environment and wood-quality versus volume production preferences. In contrast to this need for customization of drought and pest resistances, consistent large gains in productivity for all genotypes can be obtained if root traits can be altered to reduce competition for water and nutrients. Our approach illustrates the potential of using eco-evolutionary theory and modeling to guide plant breeding and genetic technology in selecting target traits in the quest for higher forest productivity. PMID:25542897

  6. Exploring within-tree architectural development of two apple tree cultivars over 6 years.

    PubMed

    Costes, E; Sinoquet, H; Kelner, J J; Godin, C

    2003-01-01

    The present study addresses the prediction of apple tree development, taking into account both the number and within-tree position of tree components. The architectural development of two trees per scion cultivar, 'Fuji' and 'Braeburn', was studied by describing all shoots over 6 years. Flowering and fruiting were observed over 3 years. The description included different scales [entire trees, axes, growth units (GUs) and metamers], and the analysis compared all axes of the trees as a function of their branching order and age. Three main aspects of vegetative development were investigated: the quantity of primary growth; the number and nature of developing axillary shoots; and meristem death. Results confirm the existence of within-tree morphological gradients, and show that the decrease in growth was comparable in magnitude for all axes and GUs, irrespective of their position. This decrease results from a reduction in the number of metamers per GU, which was modelled by an exponential function. The decrease in growth involved changes in the number and nature of the axillary shoots, which could be described by simple functions. The probability of spur death was constant over the years but differed according to cultivar and type of bearing shoot. The within-tree probability of flowering and fruiting was predictable for 'Braeburn' because axes, regardless of their position and type, had a high probability of flowering and a low probability of fruit set which led to a regular bearing habit. In contrast, 'Fuji' had an alternating bearing behaviour that was more complex to predict. This appeared to result from a synchronized increase in the probability that all GUs at tree scale are floral, combined with a high probability of fruit set. The consequences of these results for both yield prediction and architectural simulations are discussed. PMID:12495924

  7. Exploring Within?tree Architectural Development of Two Apple Tree Cultivars Over 6 Years

    PubMed Central

    COSTES, E.; SINOQUET, H.; KELNER, J. J.; GODIN, C.

    2003-01-01

    The present study addresses the prediction of apple tree development, taking into account both the number and within?tree position of tree components. The architectural development of two trees per scion cultivar, ‘Fuji’ and ‘Braeburn’, was studied by describing all shoots over 6 years. Flowering and fruiting were observed over 3 years. The description included different scales [entire trees, axes, growth units (GUs) and metamers], and the analysis compared all axes of the trees as a function of their branching order and age. Three main aspects of vegetative development were investigated: the quantity of primary growth; the number and nature of developing axillary shoots; and meristem death. Results confirm the existence of within?tree morphological gradients, and show that the decrease in growth was comparable in magnitude for all axes and GUs, irrespective of their position. This decrease results from a reduction in the number of metamers per GU, which was modelled by an exponential function. The decrease in growth involved changes in the number and nature of the axillary shoots, which could be described by simple functions. The probability of spur death was constant over the years but differed according to cultivar and type of bearing shoot. The within?tree probability of flowering and fruiting was predictable for ‘Braeburn’ because axes, regardless of their position and type, had a high probability of flowering and a low probability of fruit set which led to a regular bearing habit. In contrast, ‘Fuji’ had an alternating bearing behaviour that was more complex to predict. This appeared to result from a synchronized increase in the probability that all GUs at tree scale are floral, combined with a high probability of fruit set. The consequences of these results for both yield prediction and architectural simulations are discussed. PMID:12495924

  8. Effects of open-top chambers on 'Valencia' orange trees

    SciTech Connect

    Olszyk, D.M.; Takemoto, B.K.; Kats, G.; Dawson, P.J.; Morrison, C.L.

    1992-01-01

    Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chamber trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes.

  9. Surveying Dead Trees and CO2-Induced Stressed Trees Using AVIRIS in the Long Valley Caldera

    NASA Technical Reports Server (NTRS)

    deJong, Steven M.

    1996-01-01

    Since 1980 the Long Valley Caldera in the eastern Sierra Nevada (California) has shown signs of renewed volcanic activity. Frequent earthquakes, a re-inflation of the caldera, hydrothermal activity and gas emissions are the outer symptoms of this renewed activity. In 1990 and 1991 several areas of dying trees were found around Mammoth Mountain. The cause of the die off of the trees was first sought in the persistent drought in the preceding years. However, the trees died regardless of age and species. Farrar et al. (1995) started a soil-gas survey in 1994 in the dead-tree areas and found carbon dioxide concentrations ranging from 30 to 96% at soil depths between 30 and 60 cm. CO2 concentrations in the atmosphere are usually around 0.03% and in the soil profile CO2 levels do commonly not exceed 4 to 5%. Although not much is known about the effect of high levels of carbon dioxide in the soil profile on roots, it is most likely that the trees are dying due to oxygen deprivation: the CO2 drives the oxygen out of the soil. So far, four sites of dead trees have been mapped around Mammoth Mountain. The two largest dying trees sites are located near Horseshoe Lake and near Mammoth Mountain Main Lodge covering approximately an area of 10 and 8 ha respectively. Analysis of the gas composition regarding the He-3/He-4 ratio and the percentage biogenic carbon reveals the source of the gas: the magma body beneath the Long Valley Caldera. Until recently it was not known that volcanoes release abundant carbon dioxide from their flanks as diffuse soil emanations. As a result of the magma gas emission around Mammoth Mountain there is an excellent sequence of dead trees, stressed trees, healthy trees and bare soil surfaces. This research site provides excellent opportunities to: (1) Study the capabilities of imaging spectrometry to map stressed (and dead) pine and fir species; (2) Study methods to separate the vivid vegetation, stressed vegetation and dead vegetation from the soil background of glacial deposits and crystalline rocks. The dead tree areas are located on the flanks of Mammoth Mountain (N:37 deg 37' 45" and W:119 deg 02' 05") at an elevation between 2600 and 3000 meters. The area is covered by an open type of Montane Forest. The dominant tree species are Lodgepole Pine (Pinus contorta), the Red Fir (Abies magnifica) and the Jeffrey Pine (Pinus jeffreyi). The soil surface near Horseshoe Lake is generally fairly bright. The surface is covered by glacial deposits (till) consisting mainly of weathered granitic rocks.

  10. Water, gravity and trees: Relationship of tree-ring widths and total water storage dynamics

    NASA Astrophysics Data System (ADS)

    Creutzfeldt, B.; Heinrich, I.; Merz, B.; Blume, T.; Güntner, A.

    2012-04-01

    Water stored in the subsurface as groundwater or soil moisture is the main fresh water source not only for drinking water and food production but also for the natural vegetation. In a changing environment water availability becomes a critical issue in many different regions. Long-term observations of the past are needed to improve the understanding of the hydrological system and the prediction of future developments. Tree ring data have repeatedly proved to be valuable sources for reconstructing long-term climate dynamics, e.g. temperature, precipitation and different hydrological variables. In water-limited environments, tree growth is primarily influenced by total water stored in the subsurface and hence, tree-ring records usually contain information about subsurface water storage. The challenge is to retrieve the information on total water storage from tree rings, because a training dataset of water stored in the sub-surface is required for calibration against the tree-ring series. However, measuring water stored in the subsurface is notoriously difficult. We here present high-precision temporal gravimeter measurements which allow for the depth-integrated quantification of total water storage dynamics at the field scale. In this study, we evaluate the relationship of total water storage change and tree ring growth also in the context of the complex interactions of other meteorological forcing factors. A tree-ring chronology was derived from a Norway spruce stand in the Bavarian Forest, Germany. Total water storage dynamics were measured directly by the superconducting gravimeter of the Geodetic Observatory Wettzell for a 9-years period. Time series were extended to 63-years period by a hydrological model using gravity data as the only calibration constrain. Finally, water storage changes were reconstructed based on the relationship between the hydrological model and the tree-ring chronology. Measurement results indicate that tree-ring growth is primarily controlled by total water storage in the subsurface. But high uncertainties intervals of the correlation coefficient urges for the extension of the measurement period. This multi-disciplinary study, combining hydrology, dendrochronology and geodesy shows that temporal gravimeter measurements may give us the unique opportunity to retrieve the information of total water storage contained in tree-ring records to reconstruct total water storage dynamics. Knowing the relationship of water storage and tree-ring growth can also support the reconstruction of other climate records based on tree-ring series, help with hydrological model testing and can improve our knowledge of long-term variations of water storage in the past.

  11. TreeQ-VISTA: An Interactive Tree Visualization Tool withFunctional Annotation Query Capabilities

    SciTech Connect

    Gu, Shengyin; Anderson, Iain; Kunin, Victor; Cipriano, Michael; Minovitsky, Simon; Weber, Gunther; Amenta, Nina; Hamann, Bernd; Dubchak,Inna

    2007-05-07

    Summary: We describe a general multiplatform exploratorytool called TreeQ-Vista, designed for presenting functional annotationsin a phylogenetic context. Traits, such as phenotypic and genomicproperties, are interactively queried from a relational database with auser-friendly interface which provides a set of tools for users with orwithout SQL knowledge. The query results are projected onto aphylogenetic tree and can be displayed in multiple color groups. A richset of browsing, grouping and query tools are provided to facilitatetrait exploration, comparison and analysis.Availability: The program,detailed tutorial and examples are available online athttp://genome-test.lbl.gov/vista/TreeQVista.

  12. Computing downwards accumulations on trees quickly Jeremy Gibbons

    E-print Network

    Gibbons, Jeremy

    Computing downwards accumulations on trees quickly Jeremy Gibbons Abstract. Downwards accumulations on binary trees (Gibbons, 1991, 1993). Downwards accumulations are essentially functions which `pass infor by performing an upwards followed by a downwards accumulation using `con­ tinuations' (Gibbons, 1991); Copyright

  13. Automatic translation of digraph to fault-tree models

    NASA Technical Reports Server (NTRS)

    Iverson, David L.

    1992-01-01

    The author presents a technique for converting digraph models, including those models containing cycles, to a fault-tree format. A computer program which automatically performs this translation using an object-oriented representation of the models has been developed. The fault-trees resulting from translations can be used for fault-tree analysis and diagnosis. Programs to calculate fault-tree and digraph cut sets and perform diagnosis with fault-tree models have also been developed. The digraph to fault-tree translation system has been successfully tested on several digraphs of varying size and complexity. Details of some representative translation problems are presented. Most of the computation performed by the program is dedicated to finding minimal cut sets for digraph nodes in order to break cycles in the digraph. Fault-trees produced by the translator have been successfully used with NASA's Fault-Tree Diagnosis System (FTDS) to produce automated diagnostic systems.

  14. "Flowering Dogwood New Hampshire's Big Tree for May"

    E-print Network

    New Hampshire, University of

    a group of native dogwood trees growing in the woods on their forested property. To enjoy these beautiful of their young dogwood trees. At the time, the fear of the devastating anthracnose disease, Discula destructive

  15. Cuts and Partitions in Graphs/Trees with Applications 

    E-print Network

    Fan, Jia-Hao

    2013-07-23

    Both the maximum agreement forest problem and the multicut on trees problem are NP-hard, thus cannot be solved efficiently if P /=NP. The maximum agreement forest problem was motivated in the study of evolution trees in ...

  16. Discriminative Transfer Learning with Tree-based Priors

    E-print Network

    Toronto, University of

    knowledge among them. Our method learns to organize the classes into a tree hierarchy. This tree structure are related to tigers, lions, jaguars and leopards. Having labeled examples from these related classes should

  17. 5. TUNNEL TREE AT DRIVETHROUGHTREE PARK. LEGGETT, HUMBOLDT COUNTY, CALIFORNIA. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. TUNNEL TREE AT DRIVE-THROUGH-TREE PARK. LEGGETT, HUMBOLDT COUNTY, CALIFORNIA. LOOKING NE. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

  18. Collecting, preparing, crossdating, and measuring tree increment cores

    USGS Publications Warehouse

    Phipps, R.L.

    1985-01-01

    Techniques for collecting and handling increment tree cores are described. Procedures include those for cleaning and caring for increment borers, extracting the sample from a tree, core surfacing, crossdating, and measuring. (USGS)

  19. 13. FLOOR 1: DETAIL OF POSTS SUPPORTING BRIDGE TREE TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. FLOOR 1: DETAIL OF POSTS SUPPORTING BRIDGE TREE TO NORTH; NOTE BEADING AT CORNERS; WEDGES ADJUST HEIGHT OF PIVOTING END OF BRIDGE TREE - Pantigo Windmill, James Lane, East Hampton, Suffolk County, NY

  20. Design of a tree moving and planting device

    E-print Network

    Nabar, Sean J

    2006-01-01

    Planting trees that weigh over 200 pounds normally requires three or more able persons. Therefore, a device that allows a single person to easily and efficiently plant such trees possible by one person is highly desirable. ...