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1

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

PubMed

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

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

2013-10-01

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

Leaf litter decomposition and mulch performance from mixed and monospecific plantations of native tree species in Costa Rica  

Microsoft Academic Search

An experiment with native trees was established in 1991 on degraded pasture in the Atlantic lowlands of Costa Rica to examine the influence of mixed and monospecific plantation designs on tree growth and nutrient cycling. As part of this study, leaf litter decomposition rates and mulch performance were compared among four native tree species, Callophylum brasiliense Cambess, Jacaranda copaia (Aubl.)

Rachel Byard; Kristin C. Lewis; Florencia Montagnini

1996-01-01

4

Antioxidant and Cytotoxic Activity of Hydroethanolic Extract from Jacaranda decurrens Leaves  

PubMed Central

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

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

5

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

PubMed

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

Silva, Paulo R D da; Stefenon, Valdir M

2014-03-01

6

Trees  

NSDL National Science Digital Library

This tutorial covers various aspects of trees. It explains which chemicals cause leaves to change colors, how the process of photosynthesis works, the functions of bark, roots, pollen and leaves, and the effect of trees on nearby temperature.

7

Trees, Trees, Trees!  

NSDL National Science Digital Library

In these activities, students increase their awareness and knowledge of trees through research, literature and hands-on contact. The students will adopt and identify a tree of their choice, make a rubbing of the bark, draw a picture, and research about their tree. They will also write an original piece about their tree, document how it changes throughout the year, and learn the difference between deciduous and coniferous trees.

1998-01-01

8

Profile of volatile components of hydrodistilled and extracted leaves of Jacaranda acutifolia and their antimicrobial activity against foodborne pathogens.  

PubMed

Volatile constituents of the essential oil and n-hexane extract of Jacaranda acutifolia Humb. and Bonpl. (Bignoniaceae) leaves were determined, and their antimicrobial activities were investigated using an agar diffusion method. The minimum inhibitory concentrations (MIC) were determined and compared with those of standard antibiotics (penicillin, gentamicin and nystatin). The chemical composition of the oils was analyzed by capillary gas chromatography (GLC-FID) and gas chromatography-mass spectrometry (GLC-MS). Thirty-four components, comprising almost 93.8% of the total peak area, were identified in the leaf essential oil. The main components were methyl linolenate (26.7%), 1-octen-3-ol (10.8%), methyl phenyl acetate (9.9%), beta-linalool (5.5%) and palmitic acid (4.7%). The n-hexane extract revealed similar oil constituents, but also p-benzoquinone, phenyl acetic acid, resorcinol and homogentisic acid. The oil showed some activity against Staphylococcus aureus and Escherichia coli with MIC values of 2.2 and 2.9 mg/mL, respectively, and moderate activity against Candida albicans, Salmonella typhimurium and Shigella flexneri. The n-hexane extract showed moderate activities against all tested microorganisms, with MIC values ranging from 3.5 to 10.2 mg/mL. The antimicrobial activities of the hydrodistilled and extracted leaves make their local traditional uses rational. PMID:25230515

Singab, Abdel Nasser B; Mostafa, Nada M; Eldahshan, Omayma A; Ashour, Mohamed L; Wink, Michael

2014-07-01

9

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

10

Flower Face Face Face Face Flower Tree Tree Tree Tree  

E-print Network

Flower Flower Flower Flower Flower Face Face Face Face Flower Flower Tree Tree Tree Tree Flower Sign Face Face Face Face Sign Sign Building Sign Water Sky Tree Building Building Building Sign Book Building Building Building Sign Bird Bird Road Tree Grass Road Road Bird Sky #12;Bird Bird Water Bird Grass

Chen, Tsuhan

11

Fodder Trees  

Microsoft Academic Search

The Agrobrief 'FODDER TREES' deals with trees and shrubs mainly or partially grown to provide fodder for livestock. The information in this brochure helps extension workers in the tropics to advice farmers about feeding fodder tree leaves to cattle, goats and sheep. It describes in short how farmers can benefit from fodder trees and which type of tree, how many

André van Tol

12

What is a Tree? Tree terminology  

E-print Network

1 Trees · What is a Tree? · Tree terminology · Why trees? · What is a general tree? · Implementing trees · Binary trees · Binary tree implementation · Application of Binary trees #12;2 What is a Tree? · A tree, is a finite set of nodes together with a finite set of directed edges that define parent

Razak, Saquib

13

Tree Tally  

NSDL National Science Digital Library

In this outdoor activity and fun race, learners first find the most common type of tree in a forest site. Learners use a "transect," a kind of sampling technique, to estimate the number of different kinds of trees, and a histogram, or simple graph, to record how frequently different tree species occur in the forest. Learners also select one species of tree, and run a forest leap frog race between trees of that species. (Older learners can just run between trees without leapfrogging.)

Science, Lawrence H.

1982-01-01

14

Decision Trees Unpredictability Bias Improvements Decision Trees  

E-print Network

Decision Trees Unpredictability Bias Improvements Decision Trees #12;Decision Trees Unpredictability Bias Improvements 1 Decision Trees Using Trees Learning 2 Unpredictability Entropy Entropy for datasets Information Gain 3 Bias Bias Occam's principle Overfitting 4 Improvements #12;Decision Trees

Kjellström, Hedvig

15

Introduction to Trees Tree Application: Character Reconstruction  

E-print Network

Introduction to Trees Tree Application: Character Reconstruction Trees and Distances Organismal Trees Consensus Trees Chapter 2. Trees Weigang Qiu Department of Biological Sciences Hunter College BIOL 375 Molecular Evolution, Fall 2009 Weigang Qiu Chapter 2. Trees #12;Introduction to Trees Tree

Qiu, Weigang

16

Neighbourhood density and genetic relatedness interact to determine fruit set and abortion rates in a continuous tropical tree population  

PubMed Central

Tropical trees may show positive density dependence in fruit set and maturation due to pollen limitation in low-density populations. However, pollen from closely related individuals in the local neighbourhood might reduce fruit set or increase fruit abortion in self-incompatible tree species. We investigated the role of neighbourhood density and genetic relatedness on individual fruit set and abortion in the neotropical tree Jacaranda copaia in a large forest plot in central Panama. Using nested neighbourhood models, we found a strong positive effect of increased conspecific density on fruit set and maturation. However, high neighbourhood genetic relatedness interacted with density to reduce total fruit set and increase the proportion of aborted fruit. Our results imply a fitness advantage for individuals growing in high densities as measured by fruit set, but realized fruit set is lowered by increased neighbourhood relatedness. We hypothesize that the mechanism involved is increased visitation by density-dependent invertebrate pollinators in high-density populations, which increases pollen quantity and carry-over and increases fruit set and maturation, coupled with self-incompatibility at early and late stages due to biparental inbreeding that lowers fruit set and increases fruit abortion. Implications for the reproductive ecology and conservation of tropical tree communities in continuous and fragmented habitats are discussed. PMID:18713714

Jones, F.A; Comita, L.S

2008-01-01

17

Rain forest fragmentation and the proliferation of successional trees.  

PubMed

The effects of habitat fragmentation on diverse tropical tree communities are poorly understood. Over a 20-year period we monitored the density of 52 tree species in nine predominantly successional genera (Annona, Bellucia, Cecropia, Croton, Goupia, Jacaranda, Miconia, Pourouma, Vismia) in fragmented and continuous Amazonian forests. We also evaluated the relative importance of soil, topographic, forest dynamic, and landscape variables in explaining the abundance and species composition of successional trees. Data were collected within 66 permanent 1-ha plots within a large (approximately 1000 km2) experimental landscape, with forest fragments ranging from 1 to 100 ha in area. Prior to forest fragmentation, successional trees were uncommon, typically comprising 2-3% of all trees (> or =10 cm diameter at breast height [1.3 m above the ground surface]) in each plot. Following fragmentation, the density and basal area of successional trees increased rapidly. By 13-17 years after fragmentation, successional trees had tripled in abundance in fragment and edge plots and constituted more than a quarter of all trees in some plots. Fragment age had strong, positive effects on the density and basal area of successional trees, with no indication of a plateau in these variables, suggesting that successional species could become even more abundant in fragments over time. Nonetheless, the 52 species differed greatly in their responses to fragmentation and forest edges. Some disturbance-favoring pioneers (e.g., Cecropia sciadophylla, Vismia guianensis, V. amazonica, V. bemerguii, Miconia cf. crassinervia) increased by >1000% in density on edge plots, whereas over a third (19 of 52) of all species remained constant or declined in numbers. Species responses to fragmentation were effectively predicted by their median growth rate in nearby intact forest, suggesting that faster-growing species have a strong advantage in forest fragments. An ordination analysis revealed three main gradients in successional-species composition across our study area. Species gradients were most strongly influenced by the standlevel rate of tree mortality on each plot and by the number of nearby forest edges. Species-composition also varied significantly among different cattle ranches, which differed in their surrounding matrices and disturbance histories. These same variables were also the best predictors of total successional-tree abundance and species richness. Successional-tree assemblages in fragment interior plots (>150 m from edge), which are subjected to fragment area effects but not edge effects, did not differ significantly from those in intact forest, indicating that area effects per se had little influence on successional trees. Soils and topography also had little discernable effect on these species. Collectively, our results indicate that successional-tree species proliferate rapidly in fragmented Amazonian forests, largely as a result of chronically elevated tree mortality near forest edges and possibly an increased seed rain from successional plants growing in nearby degraded habitats. The proliferation of fast-growing successional trees and correlated decline of old-growth trees will have important effects on species composition, forest dynamics, carbon storage, and nutrient cycling in fragmented forests. PMID:16637371

Laurance, William F; Nascimento, Henrique E M; Laurance, Susan G; Andrade, Ana C; Fearnside, Philip M; Ribeiro, José E L; Capretz, Robson L

2006-02-01

18

Tree Squirrels  

Microsoft Academic Search

In this chapter tree squirrels are divided into three groups: large tree squirrels, pine squirrels, and flying squirrels. Large tree squirrels include fox (Sciurus niger), eastern gray (Sciurus carolinensis), western gray (Sciurus griseus), and tassel-eared (Sciurus aberti) squirrels. Fox squirrels (Fig. 1) measure 18 to 27 inches (46 to 69 cm) from nose to tip of tail. They weigh about

Jeffrey J. Jackson

1994-01-01

19

Tree Talk  

NSDL National Science Digital Library

In this math meets life science lesson, learners measure the circumference of local trees in order to calculate diameters. Learners use this information and a growth rate table to estimate the age of the trees. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

Rosen, S.

2010-01-01

20

Talking Trees  

ERIC Educational Resources Information Center

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…

Tolman, Marvin

2005-01-01

21

Growing Tree  

NSDL National Science Digital Library

Includes RedBlackTrees, BinarySearchTrees, and SplayTrees. It allows the user to create randomly generated input data or to insert user's own input data for a splay tree in different formats such as integer, double, and character. Users can construct a splay tree by directly inserting, deleting, and splaying tree nodes to the top. The user can also select different tree operations such as in, pre- and post-order traversals. It provides a number of flexible user controls including the speed control, stop, forward, backward steps, etc. Text-based descriptions are displayed for each algorithm step. The textual descriptions include miscellaneous information about the tree including the size, number of elements and depth. This text information can define a history of the algorithm. One of the best AVs for the splay tree. It provides interaction-oriented operations and adjustable spatial layout with intuitive animations. This AV includes almost all necessary features for the splay tree. Randomly generated input data offered many advantages for a beginner to start with some input. It also allows constructing the splay tree with user's own input dataset. The graphic representation and animation for the splay tree is intuitive and helpful for understanding each algorithm step. A small text window lists algorithm steps that are performed. The AV has a simple, intuitive interface. For new users, it can be difficult to get started, though, since there is no help facility or introduction to the AV. The user can select a node by clicking it. A context menu then appears which allows double rotation, splay to the top, and delete. Controls at the top allow nodes to be inserted. There are some weaknesses.The layout is spacious but the number representation seems sometimes misleading during the animation and transformation. There is a problem with scalability of nodes in representation of the tree. When the number of elements in the tree grows beyond 10, the nodes become too small for the user to read. There is no quiz or exercise mode to encourage self-evaluation. Some controls ambiguous . For example, although those controls present on the interface menu, backwards and forwards steps of the animation don't seem to do anything. The history window is too small. Recommended as lecture aide, standalone, self-study suppliment to tutorial or lecture.

Bob Sedgewick

22

Factor Trees  

NSDL National Science Digital Library

In this online activity, the learner finds the prime factorization of composite numbers by building factor trees. A second level includes finding the greatest common factor and the least common multiple by sorting factors using a Venn Diagram.

2010-01-01

23

Factor Trees  

NSDL National Science Digital Library

This virtual manipulative allows students to find the prime factorization of numbers by completing factor trees. Then they may use a venn diagram to sort the prime factors to find the greatest common factor and the least common multiple.

Math Playground

2009-07-29

24

Tree frog  

NSDL National Science Digital Library

This tree frog can be found living in jungles and forests. Two reasons why the common frog is considered to be an amphibian are because it lays eggs in water and its spawn goes through metamorphosis to reach adulthood.

Hans Hillewaert (None;)

2008-04-20

25

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

PubMed

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

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

2013-11-30

26

Community Trees Power Lines and Trees  

E-print Network

Community Trees Power Lines and Trees Introduction Trees serve many purposes in urban and rural trees near power lines. Most high voltage lines are not insulated, and contact will result in electric areas. To assure safe and reliable electric service, trimming or removal of trees is sometimes necessary

Koford, Rolf R.

27

Community Trees Community Tree Steward Program  

E-print Network

1 Community Trees Community Tree Steward Program ...and justice for all The U.S. Department, Iowa February, 2001 Jeff Iles Department of Horticulture Iowa State University Most tree managers realize dead trees should be removed as soon as they are detected. But living trees also can be a threat

Koford, Rolf R.

28

Minimizing Tree Automata for Unranked Trees  

E-print Network

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

Martens, Wim

29

Trees, Soil and Water  

NSDL National Science Digital Library

Trees, soil and water: Journey to Forever - health care for mountains, trees for deserts, trees for people, forest, forestry, deforestation, erosion, soil conservation, water conservation, desertification.

Keith Addison

2010-01-01

30

Tea tree oil  

MedlinePLUS

Tea tree oil is derived from the leaves of the tea tree. The tea tree was named by eighteenth century sailors, who made ... smelled like nutmeg from the leaves of the tree growing on the swampy southeast Australian coast. Do ...

31

Shade trees  

Microsoft Academic Search

Shading is an important part of computer imagery, but shaders have been based on fixed models to which all surfaces must conform. As computer imagery becomes more sophisticated, surfaces have more complex shading characteristics and thus require a less rigid shading model. This paper presents a flexible tree-structured shading model that can represent a wide range of shading characteristics. The

Robert L. Cook

1984-01-01

32

TREES, WOODS AND FORESTS  

E-print Network

SCOTLAND'S TREES, WOODS AND FORESTS #12;2 SCOTLAND'S TREES, WOODS AND FORESTS2 #12;SCOTLAND'S TREES FOR THE ENVIRONMENT CHAPTER 4 FORESTS FOR THE ECONOMY CHAPTER 5 SCOTLAND'S REMARKABLE TREES CHAPTER 6 FINDING OUT MORE SCOTLAND'S TREES, WOODS AND FORESTS #12;4 SCOTLAND'S TREES, WOODS AND FORESTS4 This booklet is written

33

Tree Torture  

NSDL National Science Digital Library

The San Pedro River is one of the only free-flowing waterways in Arizona. Though it's more of a small stream than a river, it nourishes a vibrant ecosystem known as a riparian area. Full of tall trees, it serves as a major flyway for migrating birds and provides a ribbon of green in an otherwise barren landscape. In this Science Update, you'll hear about the research being done to keep the San Pedro flowing.

Science Update;

2002-06-10

34

Parallelization: Binary Tree Traversal  

NSDL National Science Digital Library

This module teaches the use of binary trees to sort through large data sets, different traversal methods for binary trees, including parallel methods, and how to scale a binary tree traversal on multiple compute cores. Upon completion of this module, students should be able to recognize the structure of a binary tree, employ different methods for traversing a binary tree, understand how to parallelize a binary tree traversal, and how to scale a binary tree traversal over multiple compute cores.

Aaron Weeden

35

Tree Troubles  

NSDL National Science Digital Library

This Topic in Depth explores some of the diseases and other threats that certain trees must contend with to remain healthy and vital. The first website (1), from the USDA Forest Service-St. Paul Field Office, contains a collection of archived publications designed to help people diagnose, control, and identify various threats to different types of trees. Examples of these publications include: How to Control Sapstreak Disease of Sugar Maple; How to Differentiate Dutch Elm Disease From Elm Phloem Necrosis; How to Identify and Manage Needlecast Diseases on Balsam Fir; and How to Manage Eastern White Pine to Minimize Damage from Blister Rust and White Pine Weevil, to name few. The second (2) site, Forest & Shade Tree Pathology, is an online textbook that was developed by Dr. James J. Worrall, a plant pathologist for the USDA Forest Service, and former professor at the College of Environmental Science and Forestry, State University of New York. Dr. Worrall's site contains information about rusts, foliage and root diseases, parasitic plants, cankers, abiotic diseases, and wilts as well as disease profiles for Swiss Needle Cast; Oak Wilt, Chestnut Blight, Armillaria Root Disease, and more. The third (3) site, Oak Wilt: A Threat to Red Oaks & White Oaks Species, was created by Dr. David L. Roberts at Michigan State University Extension. Dr. Robert's concise site contains brief sections addressing oak wilt distribution, field diagnosis, management, disease cycle, and more. The fourth (4) site, from the California Oak Mortality Task Force, contains images, publications, maps, and information about Sudden Oak Death-related research, management recommendations, nursery issues, and regulations. The final three websites come from the USDA Forest Service and contain information about different insect threats. The fifth (5) site offers information about the emerald ash borer. The sixth (6) site provides information about the gypsy moth, and the final (7) site contains information about the Asian longhorned beetle.

36

Learning relational probability trees  

Microsoft Academic Search

Classification trees are widely used in the machine learning and data mining communities for modeling propositional data. Recent work has extended this basic paradigm to probability estimation trees. Traditional tree learning algorithms assume that instances in the training data are homogenous and independently distributed. Relational probability trees (RPTs) extend standard probability estimation trees to a relational setting in which data

Jennifer Neville; David Jensen; Lisa Friedland; Michael Hay

2003-01-01

37

Minnesota Tree Blitz  

NSDL National Science Digital Library

In this biology field experience, students will explore trees of Minnesota. Working in cooperative groups, students will discover biodiversity of trees and determine populations of tree species through observation and use of dichotomous keys.

38

American Chestnut Tree  

NSDL National Science Digital Library

This annotated slideshow adapted from KET's Electronic Field Trip to the Forest illustrates how blight decimated the American chestnut tree and the methods scientists use to identify and pollinate the remaining trees to create blight-resistant trees.

Ket

2008-09-02

39

Tree Growth Investigation  

NSDL National Science Digital Library

This activity (located on page 3 of the PDF) is a full inquiry investigation into tree growth rates. Groups of learners will count tree rings to determine each tree’s age. A thorough sample of other measurements will then be taken to calculate the trees’ fastest, slowest, and overall average growth rate. Presenting the results in a table allows learners to compare data for different types of trees. Relates to linked video, DragonflyTV GPS: Temperate Rainforest.

Twin Cities Public Television, Inc.

2007-01-01

40

Trees and Air Quality  

NSDL National Science Digital Library

In this activity, students describe the positive effects that trees have on air quality and determine how to landscape a home with trees to decrease energy use. Students will draw a map of their yard or school site showing the location of trees and check a leaf of each tree for particulates. They will then make observations on several different days to determine which trees save energy and draw on their map where more trees should be planted to save energy.

41

Essential Kurepa Trees Versus Essential Jech Kunen Trees1  

E-print Network

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

Jin, Renling

42

Protected trees A guide to tree preservation procedures  

E-print Network

Protected trees A guide to tree preservation procedures #12;Protected trees A guide to tree trees: A guide to tree preservation procedures Introduction This leaflet is written for tree owners, their neighbours and local community groups, and answers some of the most common questions about tree preservation

43

PieTree drawing phylogenetic trees and ancestral state reconstructions  

E-print Network

PieTree drawing phylogenetic trees and ancestral state reconstructions PieTree Release 0.4 Emma E Dependencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 PieTree.2 Input tree file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2

Goldberg, Emma

44

A tree-to-tree model for statistical machine translation  

E-print Network

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 ...

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

2008-01-01

45

Week 10: Consensus trees, tree distances, tests of tree March, 2010  

E-print Network

Week 10: Consensus trees, tree distances, tests of tree shape Genome 570 March, 2010 Week 10: Consensus trees, tree distances, tests of tree shape ­ p.1/40 #12;Trees we will use for consensus trees A C B E D FG A CG F B E D A CG F B E D Week 10: Consensus trees, tree distances, tests of tree shape ­ p

Borenstein, Elhanan

46

Estimating species trees from unrooted gene trees.  

PubMed

In this study, we develop a distance method for inferring unrooted species trees from a collection of unrooted gene trees. The species tree is estimated by the neighbor joining (NJ) tree built from a distance matrix in which the distance between two species is defined as the average number of internodes between two species across gene trees, that is, average gene-tree internode distance. The distance method is named NJ(st) to distinguish it from the original NJ method. Under the coalescent model, we show that if gene trees are known or estimated correctly, the NJ(st) method is statistically consistent in estimating unrooted species trees. The simulation results suggest that NJ(st) and STAR (another coalescence-based method for inferring species trees) perform almost equally well in estimating topologies of species trees, whereas the Bayesian coalescence-based method, BEST, outperforms both NJ(st) and STAR. Unlike BEST and STAR, the NJ(st) method can take unrooted gene trees to infer species trees without using an outgroup. In addition, the NJ(st) method can handle missing data and is thus useful in phylogenomic studies in which data sets often contain missing loci for some individuals. PMID:21447481

Liu, Liang; Yu, Lili

2011-10-01

47

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

E-print Network

Limit Laws for Functions of Fringe trees for Binary Search Trees and Recursive Trees Cecilia of binary search trees and random recursive trees. In particular, we give simple new proofs of the fact that the number of fringe trees of size k = kn in the binary search tree and the random recursive tree (of total

Janson, Svante

48

The Needs of Trees  

ERIC Educational Resources Information Center

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…

Boyd, Amy E.; Cooper, Jim

2004-01-01

49

Random Trees and Applications  

E-print Network

Random Trees and Applications Jean-Fran¸cois Le Gall1 Notes prepared for the Cornell Summer School;2 #12;Chapter 1 From Discrete to Continuous Trees In this chapter, we first explain how discrete random trees can be coded by discrete paths called the height function and the contour function of the tree. We

Durrett, Richard

50

Categorizing Ideas about Trees: A Tree of Trees  

PubMed Central

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

Fisler, Marie; Lecointre, Guillaume

2013-01-01

51

Tree Tectonics  

NASA Astrophysics Data System (ADS)

Nature often replicates her processes at different scales of space and time in differing media. Here a tree-trunk cross section I am preparing for a dendrochronological display at the Battle Creek Cypress Swamp Nature Sanctuary (Calvert County, Maryland) dried and cracked in a way that replicates practically all the planform features found along the Mid-Oceanic Ridge (see Figure 1). The left-lateral offset of saw marks, contrasting with the right-lateral ``rift'' offset, even illustrates the distinction between transcurrent (strike-slip) and transform faults, the latter only recognized as a geologic feature, by J. Tuzo Wilson, in 1965. However, wood cracking is but one of many examples of natural processes that replicate one or several elements of lithospheric plate tectonics. Many of these examples occur in everyday venues and thus make great teaching aids, ``teachable'' from primary school to university levels. Plate tectonics, the dominant process of Earth geology, also occurs in miniature on the surface of some lava lakes, and as ``ice plate tectonics'' on our frozen seas and lakes. Ice tectonics also happens at larger spatial and temporal scales on the Jovian moons Europa and perhaps Ganymede. Tabletop plate tectonics, in which a molten-paraffin ``asthenosphere'' is surfaced by a skin of congealing wax ``plates,'' first replicated Mid-Oceanic Ridge type seafloor spreading more than three decades ago. A seismologist (J. Brune, personal communication, 2004) discovered wax plate tectonics by casually and serendipitously pulling a stick across a container of molten wax his wife and daughters had used in making candles. Brune and his student D. Oldenburg followed up and mirabile dictu published the results in Science (178, 301-304).

Vogt, Peter R.

2004-09-01

52

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

PubMed

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.Heredity advance online publication, 15 January 2014; doi:10.1038/hdy.2013.146. PMID:24424164

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

2014-01-15

53

COMPONENT User's Guide Random trees  

E-print Network

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

Page, Roderic

54

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

E-print Network

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

Zhang, Louxin

55

Ash Tree Identification Key Ash Tree Characteristics  

E-print Network

and furrows form diamond shapes in older bark (green & white ash) opposite arrangements ­ buds, leavesAsh Tree Identification Key Ash Tree Characteristics Bark Branches diamond patterned ­ ridges berries Walnut, Hickory, Mountain-Ash: alternate branching #12;Identifying Emerald Ash Borer what to do

Walter, M.Todd

56

Minimal locked trees  

E-print Network

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 ...

Ballinger, Brad

57

Graph homomorphisms between trees  

E-print Network

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 ...

Csikvari, Peter

58

Chem-Is-Tree.  

ERIC Educational Resources Information Center

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)

Barry, Dana M.

1997-01-01

59

Tree Classification Software  

NASA Technical Reports Server (NTRS)

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.

Buntine, Wray

1993-01-01

60

Discordance of species trees with their most likely gene trees  

E-print Network

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

Degnan, James

61

8-ary tree. Overview of B-Trees  

E-print Network

Page Page Figure A.1 8-ary tree. APPENDIX A Overview of B-Trees Tree-based searching methods large, we find that often the tree is too large to fit in memory at once. Therefore, the tree is stored. In such an environment, the branches in the tree contain disk addresses, and it is not uncommon for a comparison

Yorke, James

62

Binary Search Trees Page 1 Binary Search Trees  

E-print Network

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

Allan, Vicki H.

63

State Complexity of Regular Tree Languages for Tree Pattern Matching  

E-print Network

State Complexity of Regular Tree Languages for Tree Pattern Matching Sang-Ki Ko, Ha-Rim Lee, and Yo-749, Korea {narame7,hrlee,emmous}@cs.yonsei.ac.kr Abstract. We study the state complexity of regular tree languages for tree matching problem. Given a tree t and a set of pattern trees L, we can decide whether

Han, Yo-Sub

64

Kids for Trees  

NSDL National Science Digital Library

This website provides references for students about the importance of trees to people and the environment. It discusses the interactions between trees and other organisms, how trees provide for their food and water needs, and how people use and work with trees. A teacher's guide provides background information, project and activity ideas, evaluation questions, and extensions that correspond with each student reference page. Links to related resources are included.

65

Build a Tree  

NSDL National Science Digital Library

This activity (on pages 13-18) has learners build a model tree and then figure out how to make their tree stand up by itself. This illustrates how the tall rain forest trees adapt to support a huge trunk and heavy branches, while also sending their roots out instead of down. Trees built in this activity can be used for the Rain Forest in Your Room activity that is also part of the Wonderwise Rain Forest Ecologist Activity Book.

Museum, University O.; Nebraska Cooperative Extension 4-H Youth Development

2001-01-01

66

Avery Andrews' Trees Preprocessor  

E-print Network

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

Pratt, Vaughan

67

Decision-Tree Program  

NASA Technical Reports Server (NTRS)

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.

Buntine, Wray

1994-01-01

68

RC trees revisited  

Microsoft Academic Search

RC tree approximation is a computationally simple method for calculating the signal delay of MOS circuits with several states of fanout. The author derives a formal solution of RC tree equations. Based on this solution, it is shown that even though waveforms found using RC tree approximation are inaccurate, delays are exact. The author derives the dependence of the delays

Mehinet A. Cirit

1988-01-01

69

Minnesota's Forest Trees. Revised.  

ERIC Educational Resources Information Center

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…

Miles, William R.; Fuller, Bruce L.

70

Boosting Decision Trees  

Microsoft Academic Search

A new boosting algorithm of Freund and Schapire is used to improve the performance of decision trees which are constructed usin: the information ratio criterion of Quinlan's C4.5 algorithm. This boosting algorithm iteratively constructs a series of decision tress, each decision tree being trained and pruned on examples that have been filtered by previously trained trees. Examples that have been

Harris Drucker; Corinna Cortes

1995-01-01

71

Acacia Tree Ants  

NSDL National Science Digital Library

The phenomenon is the symbiotic relationship between the acacia ant and the swollen thorn acacia tree, shown in a 2:18 minute video. The ant provides protection for the tree against preying insects and other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and the ants' larvae.

72

Winter Birch Trees  

ERIC Educational Resources Information Center

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…

Sweeney, Debra; Rounds, Judy

2011-01-01

73

The Wish Tree Project  

ERIC Educational Resources Information Center

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…

Brooks, Sarah DeWitt

2010-01-01

74

Structural Equation Model Trees  

ERIC Educational Resources Information Center

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

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

2013-01-01

75

Growth of a Pine Tree  

ERIC Educational Resources Information Center

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…

Rollinson, Susan Wells

2012-01-01

76

Distributed Contour Trees  

SciTech Connect

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.

Morozov, Dmitriy; Weber, Gunther H.

2014-03-31

77

Refining discordant gene trees  

PubMed Central

Background Evolutionary studies are complicated by discordance between gene trees and the species tree in which they evolved. Dealing with discordant trees often relies on comparison costs between gene and species trees, including the well-established Robinson-Foulds, gene duplication, and deep coalescence costs. While these costs have provided credible results for binary rooted gene trees, corresponding cost definitions for non-binary unrooted gene trees, which are frequently occurring in practice, are challenged by biological realism. Result We propose a natural extension of the well-established costs for comparing unrooted and non-binary gene trees with rooted binary species trees using a binary refinement model. For the duplication cost we describe an efficient algorithm that is based on a linear time reduction and also computes an optimal rooted binary refinement of the given gene tree. Finally, we show that similar reductions lead to solutions for computing the deep coalescence and the Robinson-Foulds costs. Conclusion Our binary refinement of Robinson-Foulds, gene duplication, and deep coalescence costs for unrooted and non-binary gene trees together with the linear time reductions provided here for computing these costs significantly extends the range of trees that can be incorporated into approaches dealing with discordance. PMID:25434729

2014-01-01

78

The Height of Increasing Trees  

Microsoft Academic Search

Increasing trees have been introduced by Bergeron, Flajolet, and Salvy [1]. This kind of notion covers several well-know classes\\u000a of random trees like binary search trees, recursive trees, and plane oriented (or heap ordered) trees. We consider the height\\u000a of increasing trees and prove for several classes of trees (including the above mentioned ones) that the height satisfies\\u000a EH\\u000a \\u000a n

Michael Drmota

2009-01-01

79

Discordance of Species Trees with Their Most Likely Gene Trees  

E-print Network

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

Rosenberg, Noah

80

From gene trees to species trees through a supertree approach  

E-print Network

From gene trees to species trees through a supertree approach Celine Scornavacca1,2, , Vincent Abstract. Gene trees are leaf-labeled trees inferred from molecular se- quences. Due to duplication events arising in genome evolution, gene trees usually have multiple copies of some labels, i.e. species

Paris-Sud XI, Université de

81

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

82

From Gene Trees to Species Trees through a Supertree Approach  

E-print Network

From Gene Trees to Species Trees through a Supertree Approach Celine Scornavacca1,2, , Vincent Abstract. Gene trees are leaf-labeled trees inferred from molecular se- quences. Due to duplication events arising in genome evolution, gene trees usually have multiple copies of some labels, i.e. species

Paris-Sud XI, Université de

83

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

84

Friends of Trees  

NSDL National Science Digital Library

Based in Portland, Oregon, the Friends of Trees organization is dedicated to restoring urban forests around the country, with a particular emphasis on the Portland metropolitan area. As their Web site notes, "Trees are an essential part of the urban ecosystem. They help keep our water and air clean, prevent erosion, provide wildlife habitat, and make neighborhoods greener, more beautiful places to live." On the site, visitors can read about their ongoing planting activities and browse the newsletter they publish three times a year. For most visitors, the most helpful area of the site will be the Tree Resources section. Here, users can look through a fact sheet on the benefits of trees in urban environments, the care and maintenance of trees, and a large tree database.

85

Condensation in nongeneric trees  

E-print Network

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 $n^{-\\beta}$.

Thordur Jonsson; Sigurdur Orn Stefansson

2011-01-04

86

In Focus: The Tree  

NSDL National Science Digital Library

In Focus: The Tree, is a Getty Museum exhibition of 41 images inspired by trees. On the exhibition's website visitors can see five images of trees, from Myoung Ho Lee, William Henry Fox Talbot, Darius Kinsey, Rhea Garen, and Simryn Gill, most accompanied by audio of curators or the artists discussing their work. Curator FranÃÂçoise Reynaud explains how early photographer Talbot may have created his 1842 salt print showing a bare oak tree in winter; living artist Rheas Garen discusses her picture "Treehouse", which shows a backyard where a tree dwarfs the house, taken with a large format camera in 1993. The associated book, The Tree in Photographs, compiled by Reynaud, includes eighty-one images selected from the Museum's permanent collection.

87

Tree genetics and improvement  

SciTech Connect

Tree improvement is a complex science and a multifaceted art. Tree improvement is most valuable when integrated within land-management programs. Major efforts are currently geared to developing improved seed for reforestation programs. Progeny testing is now a routine part of tree-improvement programs. Topics such as advanced-generation breeding, shortened generations, resistance breeding, and control of cone and seed insects are being given priority. Activity continues in basic research, involving genetic engineering, tissue culture, and population theory.

Bey, C.F.; Houston, D.B.; Dinus, R.J.

1986-01-01

88

COMPONENT User's Guide Working with trees  

E-print Network

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

Page, Roderic

89

Bronchi, Bronchial Tree, & Lungs  

MedlinePLUS

... Larynx & Trachea Bronchi, Bronchial Tree, & Lungs Review Quiz Digestive System General Structure Regions of the Digestive System Mouth Pharynx & Esophagus Stomach Small & Large Intestine Accessory ...

90

COMPONENT User's Guide Comparing trees  

E-print Network

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

Page, Roderic

91

National Register of Big Trees  

NSDL National Science Digital Library

Most trees can outlive us. Even so, it's not unusual for trees to succumb to disease, insects, over development and drought. So it's especially meaningful when a tree reaches a good old age. Here you'll find out all about the oldest trees on earth, as well as have the opportunity to nominate a old tree you might know.

Forests, American

92

TreeCmp: Comparison of Trees in Polynomial Time  

PubMed Central

When a phylogenetic reconstruction does not result in one tree but in several, tree metrics permit finding out how far the reconstructed trees are from one another. They also permit to assess the accuracy of a reconstruction if a true tree is known. TreeCmp implements eight metrics that can be calculated in polynomial time for arbitrary (not only bifurcating) trees: four for unrooted (Matching Split metric, which we have recently proposed, Robinson-Foulds, Path Difference, Quartet) and four for rooted trees (Matching Cluster, Robinson-Foulds cluster, Nodal Splitted and Triple). TreeCmp is the first implementation of Matching Split/Cluster metrics and the first efficient and convenient implementation of Nodal Splitted. It allows to compare relatively large trees. We provide an example of the application of TreeCmp to compare the accuracy of ten approaches to phylogenetic reconstruction with trees up to 5000 external nodes, using a measure of accuracy based on normalized similarity between trees.

Bogdanowicz, Damian; Giaro, Krzysztof; Wróbel, Borys

2012-01-01

93

Rooting for Trees: Volunteers to Plant 20 Trees, Mark Tree Campus USA Honor  

E-print Network

Rooting for Trees: Volunteers to Plant 20 Trees, Mark Tree Campus USA Honor March 22, 2013 Event at The University of Texas at Austin will join the university urban forestry team in planting 20 large trees on the grounds of the Dell Pediatric Research Institute. Volunteers will also mulch more than 100 existing trees

Hofmann, Hans A.

94

Biodiversity and Evolutionary Trees  

NSDL National Science Digital Library

In this interactive activity, learners analyze seashells to explore phylogeny and evolution. Learners identify similar and dissimilar seashells to create a phylogenetic tree. The Teacher Guide includes pre-activity video clip suggestions and a pre-activity sorting exercise. The Teacher Guide also includes instructions on how learners can draw a phylogenetic tree instead of using the online interactive.

2013-09-14

95

Fragmentation of random trees  

NASA Astrophysics Data System (ADS)

We study fragmentation of a random recursive tree into a forest by repeated removal of nodes. The initial tree consists of N nodes and it is generated by sequential addition of nodes with each new node attaching to a randomly-selected existing node. As nodes are removed from the tree, one at a time, the tree dissolves into an ensemble of separate trees, namely, a forest. We study statistical properties of trees and nodes in this heterogeneous forest, and find that the fraction of remaining nodes m characterizes the system in the limit N\\to ? . We obtain analytically the size density {{? }s} of trees of size s. The size density has power-law tail {{? }s}? {{s}-? } with exponent ? =1+\\frac{1}{m}. Therefore, the tail becomes steeper as further nodes are removed, and the fragmentation process is unusual in that exponent ? increases continuously with time. We also extend our analysis to the case where nodes are added as well as removed, and obtain the asymptotic size density for growing trees.

Kalay, Z.; Ben-Naim, E.

2015-01-01

96

Leonardo's Tree Theory  

NSDL National Science Digital Library

This activity focuses on Leonardo da Vinci's tree theory, which states that the cross-sectional area of a major limb is approximately equal to the cross-sectional areas of its two offshoot limbs. Students test this theory by collecting data from 10 trees and perform the mathematical calculations. In addition to data collection skills, this exercise strengthens problem solving skills.

Werner, Suzanne K.

2003-03-01

97

Optimal junction Trees  

Microsoft Academic Search

The paper deals with optimality issues in connectionwith updating beliefs in networks. Weaddress two processes: triangulation and constructionof junction trees. In the first part,we give a simple algorithm for constructingan optimal junction tree from a triangulatednetwork. In the second part, we argue thatany exact method based on local calculationsmust either be less efficient than the junctiontree method, or it has

Finn Verner Jensen; Frank Jensen

1994-01-01

98

Survival of Trees  

NSDL National Science Digital Library

In this video a scientist explains how DNA extracted from ancient tree remains provides insights about how trees/plants have adapted, over time, to changes in CO2 in the atmosphere. Her lab research investigates changes in plant genotypes under experimental conditions that simulate potential changes in CO2 levels in the future.

National Science Foundation

99

Tree Diagrams and Probability  

NSDL National Science Digital Library

This lesson is designed to develop students' ability to create tree diagrams and figure probabilities of events based on those diagrams. This lesson provides links to discussions and activities related to tree diagrams as well as suggested ways to work them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

2011-01-20

100

Trees From Helicopters, Continued  

NSDL National Science Digital Library

Maples are very interesting trees with lots of variation in form. They provide us with a view of diversity in plants as well as a chance to look at natural phenomena that is very common to anyone who has had a maple tree near them. The main purpose is to

Richard Konicek-Moran

2009-04-01

101

Trees Are Terrific!  

ERIC Educational Resources Information Center

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…

Braus, Judy, Ed.

1992-01-01

102

CSI for Trees  

ERIC Educational Resources Information Center

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.…

Rubino, Darrin L.; Hanson, Deborah

2009-01-01

103

The Flame Tree  

ERIC Educational Resources Information Center

Lewis's own experiences living in Indonesia are fertile ground for telling "a ripping good story," one found in "The Flame Tree." He hopes people will enjoy the tale and appreciate the differences of an unfamiliar culture. The excerpt from "The Flame Tree" will reel readers in quickly.

Lewis, Richard

2004-01-01

104

TRANSPLANTING SHADE TREES.  

ERIC Educational Resources Information Center

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,…

Illinois Univ., Urbana. Coll. of Agriculture.

105

LVIS Tree Height Cross Section (tree texture)  

NSDL National Science Digital Library

This animation starts with a false-color map of tree heights north of San Jose, Costa Rica, and changes to a close-up 3D cut-away of a section of the forest with simulated green canopy. Data from LVIS observations taken in March, 1998.

Jones, Randall; Blair, Bryan

1999-09-17

106

binary-tree B-tree Hashing Space-Filling based location  

E-print Network

#12;#12;#12;binary-tree B-tree Hashing Space-Filling Quad-tree based location keys R -tree+ PLOP Hashing EXCELL R-tree Grid-files kd-tree kd-B-treeBD-tree 1984 1985 1986 1987 1988 1989 1990 1991 1992 LSD-tree GBD-tree skd-tree Packed R-tree multi-level GF Cell-tree hB-tree R-files GGF mkd-tree 4d-tree 4d-tree

Ooi, Beng Chin

107

Lazy decision trees  

SciTech Connect

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.

Friedman, J.H.; Yun, Yeogirl [Stanford Univ., CA (United States); Kohavi, R. [Silicon Graphics, Inc., Mountain View, CA (United States)

1996-12-31

108

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

109

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

110

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

111

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

112

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

113

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

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

Duval, Art

114

What Tree Is It?  

NSDL National Science Digital Library

This online tree-identification tool was created by the Ohio Public Library Information Network (OPLIN) and the Ohio Historical Society (OHS). Users work their way through qualities of leaves and fruits, selecting images that more closely resemble their sample. Fact pages provide instruction on fruit and leaf structures and terminology, close-up photographs of seeds, fruits, bark, leaves, or other plant parts useful in identifying the tree, as well as a picture of the full tree and information about its habitat, history, and structure.

115

Learning classification trees  

NASA Technical Reports Server (NTRS)

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.

Buntine, Wray

1991-01-01

116

The Average Height of Binary Trees and Other Simple Trees  

Microsoft Academic Search

The average height of a binary tree with n internal nodes is shown to be asymptotic to 2 6. This represents the average stack height of the simplest recursive tree traversal algorithm. The method used in this estimation is also applicable to the analysis of traversal algorithms of unary-binary trees, unbalanced 2-3 trees, t-ary trees for any t, and other

Philippe Flajolet; Andrew M. Odlyzko

1982-01-01

117

ENERGY SAVINGS WITH TREES1  

Microsoft Academic Search

In conventional buildings, trees increase, decrease, or have little effect on energy use depending on general climate, building type, tree species, and tree location. Tree arrangements that save energy provide shade primarily for east and west walls and roofs and wind protection from the direction of prevailing winter winds. Particularly for buildings specially designed to use solar energy and those

Gordon M. Heisler

1986-01-01

118

COMPONENT User's Guide Consensus trees  

E-print Network

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

Page, Roderic

119

A future with broadleaved trees  

E-print Network

A future with broadleaved trees A strategy for the Improvement of broadleaved trees in Britain and Ireland 2013-2025 Supported by #12;2 A future with broAdleAved trees Many people and organisations from and highlights areas where we believe further consideration is required. Future Trees Trust, Earth Trust

120

Compositions of Tree Series Transformations  

E-print Network

Compositions of Tree Series Transformations A. Maletti Institute of Theoretical Computer Science Germany URL: http://www.inf.tu-dresden.de/ #12;#12;Compositions of Tree Series Transformations Andreas@tcs.inf.tu-dresden.de Abstract Tree series transformations computed by bottom-up and top-down tree series transducers are called

Reyle, Uwe

121

Tea Tree Oil  

MedlinePLUS

... to-treat bacterial infections such as methicillin-resistant Staphylococcus aureus (MRSA). However, large, well-designed clinical trials on ... 40(3):175–178. Halcón L, Milkus K. Staphylococcus aureus and wounds: a review of tea tree oil ...

122

Tree of Hexagons  

NSDL National Science Digital Library

In this activity students use measuring skills and follow directions to make a three-dimensional ornament. Learners construct hexagons of graduated sizes from circles and assemble them into a tree. Complete instructions are provided.

2011-01-01

123

Leonardo's Tree Theory.  

ERIC Educational Resources Information Center

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)

Werner, Suzanne K.

2003-01-01

124

Construct a phylogenetic tree  

NSDL National Science Digital Library

This web page will construct a phylogenetic tree of the creatures you select below. It will use the protein sequences of the protein cytochrome c from each of these organisms to construct the tree. Select the desired creatures from the lists below. To select more than one in the same list, hold down the apple key (on Macs); the control key (on PCs); on the Suns, you just click. If you want to clear your selections and start over, click the "Clear all selections" button. You must also choose one and only one outgroup organism so that your tree will have a root. This is especially important for the parsimony analysis. The outgroup organism should not be closely related to the other organisms. When you have made the selections you want, click the "calculate tree" button. Your request will then be processed. This may take a while, so please be patient.

Brian White

2012-06-28

125

Combining Binary Search Trees  

E-print Network

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 ...

Demaine, Erik D.

126

Generalized constructive tree weights  

SciTech Connect

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.

Rivasseau, Vincent, E-mail: vincent.rivasseau@th.u-psud.fr, E-mail: adrian.tanasa@ens-lyon.org [LPT, CNRS UMR 8627, Univ. Paris 11, 91405 Orsay Cedex, France and Perimeter Institute for Theoretical Physics, 31 Caroline St. N, Ontario N2L 2Y5, Waterloo (Canada)] [LPT, CNRS UMR 8627, Univ. Paris 11, 91405 Orsay Cedex, France and Perimeter Institute for Theoretical Physics, 31 Caroline St. N, Ontario N2L 2Y5, Waterloo (Canada); Tanasa, Adrian, E-mail: vincent.rivasseau@th.u-psud.fr, E-mail: adrian.tanasa@ens-lyon.org [Université Paris 13, Sorbonne Paris Cité, 99, Avenue Jean-Baptiste Clément LIPN, Institut Galilée, CNRS UMR 7030, F-93430 Villetaneuse, France and Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele (Romania)] [Université Paris 13, Sorbonne Paris Cité, 99, Avenue Jean-Baptiste Clément LIPN, Institut Galilée, CNRS UMR 7030, F-93430 Villetaneuse, France and Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele (Romania)

2014-04-15

127

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

E-print Network

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

Duchowski, Andrew T.

128

Core Based Trees (CBT)  

Microsoft Academic Search

One of the central problems in one-to-many wide-area communications is forming the delivery tree - the collection of nodes and links that a multicast packet traverses. Significant problems remain to be solved in the area of multicast tree formation, the problem of scaling being paramount among these.In this paper we show how the current IP multicast architecture scales poorly (by

Tony Ballardie; Paul Francis; Jon Crowcroft

1993-01-01

129

Oscillation damping in trees.  

PubMed

Oscillation damping is of vital importance for trees to withstand strong gusty winds. Tree adaptation to wind loading takes place over a long time and during a storm only passive damping mechanisms can reduce the impact of the wind on trunk and roots. Structural damping, a phenomenon, which is associated with the conspicuous movements of the branches relative to the trunk is of particular importance. Primary and higher order branches can be seen as multiple tuned mass dampers. Moreover, as the frequency bands overlap within branches and between primary branches and the entire tree, resonance energy transfer can distribute mechanical energy over the entire tree, such that it is dissipated more effectively than in a tree with stiff branches and not so much focused on the tree trunk and the roots. Theoretical studies using modal analysis and finite element methods have supported these assertions. Next to "multiple mass damping" and "multiple resonance damping", both characterized by linear coupling between the elements, a third non linear mode, operative at large amplitudes has been identified: "damping by branching". In all these not mutually exclusive concepts frequency tuning between the elements appears to be a fundamental requisite. PMID:23602100

Spatz, Hanns-Christof; Theckes, Benoit

2013-06-01

130

The Ubiquitous B-Tree  

Microsoft Academic Search

B-trees have become, de facto, a standard for file organization. File indexes of users, dedicated database systems, and general-purpose access methods have all been proposed and implemented using B-trees. This paper reviews B-trees and shows why they have been so successful. It discusses the major variations of the B-tree, especially the W-tree, contrasting the relative merits and costs of each

Douglas E. Comer

1979-01-01

131

The Inference of Gene Trees with Species Trees  

PubMed Central

This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree–species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree–species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution. PMID:25070970

Szöll?si, Gergely J.; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

2015-01-01

132

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

8. 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

Monk, Don

133

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

134

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

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

Monk, Don

135

Recommended Trees for Colorado Front Range  

E-print Network

and unsightly. Do Not Top Your Trees! #12;Eastern redcedar* (Juniperus virginiana) Very hardy tree, excellent windbreak tree, green summer foliage, rusty brown in the winter Rocky Mountain juniper* (Juniperus scopulorum) Very hardy tree, excellent windbreak tree Trees to avoid! Selecting the right tree for the right

136

Trees: Recorders of Climate Change  

NSDL National Science Digital Library

In this activity, learners are introduced to tree rings by examining a cross section of a tree, also known as a “tree cookie.” They discover how tree age can be determined by studying the rings and how ring thickness can be used to deduce times of optimal growing conditions. Next they investigate simulated tree rings by applying the scientific method to explore how climatic conditions varied during the Little Ice Age. Use this activity to begin discussions on global warming and climate change. This lesson guide includes background information and handouts. Note: cost of materials does not include cost of purchasing "tree cookies."

2012-03-30

137

Tree Impact Study  

NSDL National Science Digital Library

In this field activity, students document examine the role of a tree in its ecosystem and as part of the environment in a human community. Students measure the tree's dimensions, examine co-residing organisms, leaf litter, and soil, and research the tree's history, using interviews or archival resources. A measuring stick, sturdy string, and an outdoor thermometer are required. An art project concludes the exploration. This activity is supported by a textbook chapter, "A History of Forest use in the Pacific Northwest,â part of the unit, A New World View, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

138

Forest & Shade Tree Pathology  

NSDL National Science Digital Library

Forest & Shade Tree Pathology is a site created by Jim Worrall, a former professor at the College of Environmental Science and Forestry. The major focus of this resource is the study of tree diseases, "their causes (etiology), factors that affect their spread (epidemiology), ecological and economic impacts, and management." The site is divided into four sections: "Main Topics" such as fungi, root diseases and wilts; "General Topics," which includes quizzes, references, and links to other forest health sites; "Disease Profiles," which includes information on specific diseases like chestnut blight and armillaria root disease; and "Disease Notes," which contains news and updates on specific diseases.

2008-02-01

139

Trees and Carbon  

NSDL National Science Digital Library

The transport and transformation of substances in the environment are known collectively as biogeochemical cycles. These global cycles involve the circulation of elements and nutrients that sustain both the biological and physical aspects of the environment. As an example, this discussion centers around the carbon cycle and how carbon is sequestered in trees. Students will perform an activity that replicates a case study in which the biomass of trees in a 15-acre plot of forest was calculated to determine the amount of carbon sequestered per acre.

Pratte, John

140

Influence of tree characteristics and forest management on tree microhabitats  

Microsoft Academic Search

Higher densities of tree microhabitats in unmanaged forests may explain biodiversity differences with managed forests. To better understand the determinants of this potential biodiversity indicator, we studied the influence of tree characteristics on a set of tree microhabitats (e.g. cavities, cracks, bark features) on 75 plots in managed and unmanaged French forests. We hypothesized that the number of different microhabitat

Aurélie Vuidot; Yoan Paillet; Frédéric Archaux; Frédéric Gosselin

2011-01-01

141

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....

142

Can These Trees Be Saved?  

E-print Network

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....

Taylor, Eric; Foster, C. Darwin

2005-10-19

143

Classify the trees/Leaves  

NSDL National Science Digital Library

This activity is a field investigation where students gather leaves from various trees on school property, interpret findings, name tree and leaves, journal activity and develop a new "aha" for nature!

Mary Walsh

144

An Introduction to Tree Diagrams  

NSDL National Science Digital Library

This brief article describes the use of tree diagrams in calculating probabilities. The author provides examples of how tree diagrams are used to calculate specific probabilities and why the language chosen relates to the operations used to find the probability.

Cork, Stu

2014-01-01

145

Street Trees and Intersection Safety  

Microsoft Academic Search

Abstract This study and report is about street trees and intersection safety in urban contexts. The study derives from a rather simple, straightforward observation: that on the best tree-lined streets the trees come close to the corners. They do not stop at some distance back from the intersecting street right-of-way. Indeed, in Paris, a city noted for its street trees,

Elizabeth Macdonald; Alethea Harper; Jason A. Hayter

2006-01-01

146

Induction of decision trees  

Microsoft Academic Search

The technology for building knowledge-based systems by inductive inference from examples has been demonstrated successfully in several practical applications. This paper summarizes an approach to synthesizing decision trees that has been used in a variety of systems, and it describes one such system, ID3, in detail. Results from recent studies show ways in which the methodology can be modified to

J. Ross Quinlan

1986-01-01

147

Hug a Tree!  

ERIC Educational Resources Information Center

Methods for teaching pupils to use their senses to explore colors, shapes, textures, and sounds of the great outdoors are described. Ideas include: (1) having children hug their own special tree; (2) looking for geometric shapes in nature; (3) taking nocturnal nature walks; (4) building a track for racing insects; and (5) collecting objects with…

Rockwell, Robert E.; And Others

1983-01-01

148

Digging Deeper with Trees.  

ERIC Educational Resources Information Center

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)

Growing Ideas, 2001

2001-01-01

149

Tree & Stand Measurement  

E-print Network

are measured for a variety of reasons including forest management planning, forest health monitoring and timber the height but in this case in 16' foot (or partial) logs. To use the hypsometer, pace 66 feet (1 chain) from the tree. Hold the stick at 25" from eye and line botton of stick with stump - read number of logs

New Hampshire, University of

150

Tree theorem for inflation  

SciTech Connect

It is shown that the generating function for tree graphs in the ''in-in'' formalism may be calculated by solving the classical equations of motion subject to certain constraints. This theorem is illustrated by application to the evolution of a single inflaton field in a Robertson-Walker background.

Weinberg, Steven [Theory Group, Department of Physics, University of Texas, Austin, Texas, 78712 (United States)

2008-09-15

151

Tree-Ties.  

ERIC Educational Resources Information Center

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…

Gresczyk, Rick

152

Phylogenics & Tree-Thinking  

ERIC Educational Resources Information Center

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…

Baum, David A.; Offner, Susan

2008-01-01

153

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...

154

Why trees live longer?  

NASA Astrophysics Data System (ADS)

Through simulations of the bit string model for biological aging, we reproduced the observed feature of trees and some species of fish of high maximum lifespans if fertility increases with age. Our results provide an additional evidence for the importance of the mutation accumulation theory from biological aging.

de Menezes, M. Argollo; Racco, A.; Penna, T. J. P.

1996-02-01

155

Tree Fertilization Soil Analysis  

E-print Network

Tree Fertilization #12;Soil Analysis vs. Foliar Analysis #12;Macronutrients N P K Mg S Ca Micronutrients Fe Mn Zn Mo Cu Cl B #12;Complete fertilizer N P K #12;Fertilizer Analysis Percentages of N P K #12;ANSI A-300 Fertilizer Standard Standards are used to develop contract specifications. Fertilize

156

The Growth of Trees  

Microsoft Academic Search

JUST fifty years ago I was at school ia Salisbury. I have only visited it once since until last week, when I had the unique pleasure of rambling over the old but familiar haunts, of course including Old Sarum. On mounting the outer ring of the well-known mound from the Stratford side, a beech tree in the bottom of the

W. Symons

1882-01-01

157

Christmas Tree Category Manual.  

ERIC Educational Resources Information Center

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…

Bowman, James S.; Turmel, Jon P.

158

Measure a Tree  

NSDL National Science Digital Library

This activity introduces measurement and scale using hands-on activities. In this activity, students use the concept of similar triangles to determine the height of a tree. This activity is one of several available on an educational poster related to NASA's Space Interferometry Mission.

159

Rate of tree carbon accumulation increases continuously with tree size  

USGS Publications Warehouse

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.

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

160

Building Your Own Abseil Tree.  

ERIC Educational Resources Information Center

The foot and mouth crisis forced many British outdoor education providers to develop new options. The construction of an abseiling tree is described, which requires a living, healthy, straight tree with a trunk thick enough to remain stable under load and with few branches in the lower 15-20 meters. An abseil tree code of practice is presented.…

Barnett, Des

2002-01-01

161

New Life From Dead Trees  

ERIC Educational Resources Information Center

There are numerous bird species that will nest only in dead or dying trees. Current forestry practices include clearing forests of these snags, or dead trees. This practice is driving many species out of the forests. An illustrated example of bird succession in and on a tree is given. (MA)

DeGraaf, Richard M.

1978-01-01

162

Our Air: Unfit for Trees.  

ERIC Educational Resources Information Center

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,…

Dochinger, Leon S.

163

Trees and Dags An Introduction  

E-print Network

Chapter 5 Trees and Dags An Introduction to Separation Logic c #2007 John C. Reynolds February 28, 2007 In this chapter, we consider various representations of abstract tree­like data. In general­expressions are the initial lawless algebra with an infinite number of constants and one binary operation.) 5.1 Trees We use

Andrews, Peter B.

164

Singular spectrum for radial trees  

E-print Network

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.

Jonathan Breuer; Rupert L. Frank

2008-06-03

165

Building up rhetorical structure trees  

SciTech Connect

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.

Marcu, D. [Univ. of Toronto, Ontario (Canada)

1996-12-31

166

The height of increasing trees  

Microsoft Academic Search

Abstract We extend results about heights of random trees (Devroye, 1986, 1987, 1998b). In this paper, a general split tree model is considered in which the normalized subtree sizes of nodes converge in distribution. The height of these trees is shown,to be in probability asymptotic to c logn for some constant c. We apply our results to obtain a law

Nicolas Broutin; Luc Devroye; E. Mcleish; M. De La Salle

2008-01-01

167

Bkd-Tree: A Dynamic Scalable kd-Tree  

Microsoft Academic Search

\\u000a In this paper we propose a new index structure, called the Bkd-tree, for indexing large multi-dimensional point data sets.\\u000a The Bkd-tree is an I\\/O-efficient dynamic data structure based on the kd-tree. We present the results of an extensive experimental\\u000a study showing that unlike previous attempts on making external versions of the kd-tree dynamic, the Bkd-tree maintains its\\u000a high space utilization

Octavian Procopiuc; Pankaj K. Agarwal; Lars Arge; Jeffrey Scott Vitter

168

Riparian Forest Grows Trees fall in  

E-print Network

Riparian Forest Grows Trees Die Trees fall in the lake Trees leave the littoral zone "Life" Cycle of Coarse Woody Habitat #12;Riparian Forest Grows What factors drive the species composition and stand structure? Trees Die Trees fall in the lake Trees leave the littoral zone #12;Riparian Forest Grows What

169

Binary search trees of bounded balance  

Microsoft Academic Search

A new class of binary search trees, called trees of bounded balance, is introduced. These trees are easy to maintain in their form despite insertions and deletions of nodes, and the search time is only moderately longer than in completely balanced trees. Trees of bounded balance differ from other classes of binary search trees in that they contain a parameter

Jürg Nievergelt; Edward M. Reingold

1972-01-01

170

Rate of tree carbon accumulation increases continuously with tree size.  

PubMed

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

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

171

Rate of tree carbon accumulation increases continuously with tree size  

NASA Astrophysics Data System (ADS)

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.

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.

2014-03-01

172

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

E-print Network

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

Page, Roderic

173

Hasse Diagrams for Classes of Deterministic Bottom-Up Tree-to-Tree-Series  

E-print Network

Hasse Diagrams for Classes of Deterministic Bottom-Up Tree-to-Tree-Series Transformations Andreas The relationship between classes of tree-to-tree-series and o-tree-to-tree-series trans- formations, which are computed by restricted deterministic bottom-up weighted tree transducers, is investigated. Essentially

Reyle, Uwe

174

Insert tree completion system  

SciTech Connect

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.

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

1982-09-01

175

A Tree of Genetic Traits  

NSDL National Science Digital Library

Learners mark their traits for tongue rolling, PTC tasting (a harmless, bitter chemical), and earlobe attachment on tree leaf cut-outs. They then place their leaves on a large tree with branches, in which each each branch represents a different combination of traits. When completed, the tree forms a visual representation of the frequency of trait combinations within the group. Included are handouts in English and Spanish. This resource also contains information about PTC safety.

Molly Malone

2006-01-01

176

Barking up the Right Tree  

ERIC Educational Resources Information Center

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.…

Houston, Paul D.

2006-01-01

177

A Novel Approach for Compressing Phylogenetic Trees  

Microsoft Academic Search

\\u000a Phylogenetic trees are tree structures that depict relationships between organisms. Popular analysis techniques often produce\\u000a large collections of candidate trees, which are expensive to store. We introduce TreeZip, a novel algorithm to compress phylogenetic\\u000a trees based on their shared evolutionary relationships. We evaluate TreeZip’s performance on fourteen tree collections ranging\\u000a from 2,505 trees on 328 taxa to 150,000 trees on

Suzanne J. Matthews; Seung-Jin Sul; Tiffani L. Williams

2010-01-01

178

Binary Join Trees  

E-print Network

only one neighbor, and therefore it can send a message to its neighbor right away without waiting for any messages. 3.2.2 Rule 2 (Marginals) When a node r has received a message from each of its neighbors, it combines all messages together with its own... ?(? 2 ?? 2 ) ?D )?? 3 ?D )??), then we obtain the binary join tree structure shown in Figure 5. {W, X} ? ?{W, Y}{W, X, Y} {W, Z} ? {W, X, Y, Z} {W, Y}{X, Y, Z}? ? ? ??? ? (?????) ?{X, Y, Z} ? (?????) ?{W, Z} (???) ?{W, X, Y} (??(???) ?{W, X, Y} ) ?{W...

Shenoy, Prakash P.

1996-01-01

179

Redrawing Humanity's Family Tree  

NSDL National Science Digital Library

This New York Times article details two skulls, one from central Africa and the other from the Black Sea republic of Georgia, that "have shaken the human family tree to its roots, sending scientists scrambling to see if their favorite theories are among the fallen fruit." The article discusses how the two skulls have caused scientists to rethink not only how we conceive of human evolution and its chain of events, but even the geography of evolution and migration patterns of very early humans.

Wilford, John N.

1969-12-31

180

Exploring Trees and Ponds  

NSDL National Science Digital Library

Trees and Ponds is a collection of activities to be implemented with middle school youth in out-of-school environments. The website provides a rationale and goal of the activities, curriculum activities and resources such as relevant digital photos. Available for free as downloadable PDFs, these activities provide a structure for youth in out-of-school programs to carry out long-term observations of natural objects. This project uses a qualitative approach, where changes over time are studied, recorded (by youth through writing, drawing, and digital photography), and discussed.

181

COMPONENT User's Guide Maps between trees  

E-print Network

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

Page, Roderic

182

THE HEIGHT OF INCREASING TREES MICHAEL DRMOTA  

E-print Network

THE HEIGHT OF INCREASING TREES MICHAEL DRMOTA Abstract. Increasing trees have been introduced the height of increasing trees and prove for several classes of trees (including the above mentioned ones will focus on the height Hn of increasing trees of size n.) Bergeron, Flajolet and Salvy [1] have already

Drmota, Michael

183

DIF Trees: Using Classification Trees to Detect Differential Item Functioning  

ERIC Educational Resources Information Center

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…

Vaughn, Brandon K.; Wang, Qiu

2010-01-01

184

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

185

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

E-print Network

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

Della Vedova, Gianluca

186

iGLASS: An Improvement to the GLASS Method for Estimating Species Trees from Gene Trees  

E-print Network

iGLASS: An Improvement to the GLASS Method for Estimating Species Trees from Gene Trees ETHAN M. JEWETT and NOAH A. ROSENBERG ABSTRACT Several methods have been designed to infer species trees from gene trees while taking into account gene tree/species tree discordance. Although some of these methods

Rosenberg, Noah

187

12 Binary Search Trees The search tree data structure supports many dynamic-set operations, including  

E-print Network

12 Binary Search Trees The search tree data structure supports many dynamic-set operations tree both as a dictionary and as a priority queue. Basic operations on a binary search tree take time proportional to the height of the tree. For a complete binary tree with n nodes, such operations run in ,.lg n

188

Non-crossing Trees are Almost Conditioned Galton-Watson trees1  

E-print Network

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

Marckert, Jean-François

189

7 CFR 1214.3 - Christmas tree.  

Code of Federal Regulations, 2014 CFR

...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...

2014-01-01

190

7 CFR 1214.3 - Christmas tree.  

Code of Federal Regulations, 2012 CFR

...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...

2012-01-01

191

7 CFR 1214.3 - Christmas tree.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

192

Genome Trees from Conservation Profiles  

PubMed Central

The concept of the genome tree depends on the potential evolutionary significance in the clustering of species according to similarities in the gene content of their genomes. In this respect, genome trees have often been identified with species trees. With the rapid expansion of genome sequence data it becomes of increasing importance to develop accurate methods for grasping global trends for the phylogenetic signals that mutually link the various genomes. We therefore derive here the methodological concept of genome trees based on protein conservation profiles in multiple species. The basic idea in this derivation is that the multi-component “presence-absence” protein conservation profiles permit tracking of common evolutionary histories of genes across multiple genomes. We show that a significant reduction in informational redundancy is achieved by considering only the subset of distinct conservation profiles. Beyond these basic ideas, we point out various pitfalls and limitations associated with the data handling, paving the way for further improvements. As an illustration for the methods, we analyze a genome tree based on the above principles, along with a series of other trees derived from the same data and based on pair-wise comparisons (ancestral duplication-conservation and shared orthologs). In all trees we observe a sharp discrimination between the three primary domains of life: Bacteria, Archaea, and Eukarya. The new genome tree, based on conservation profiles, displays a significant correspondence with classically recognized taxonomical groupings, along with a series of departures from such conventional clusterings. PMID:16362074

Tekaia, Fredj; Yeramian, Edouard

2005-01-01

193

Elemental composition of tree nuts  

Microsoft Academic Search

Growing nut trees is becoming ever more popular among home gardeners and publications dealing with their culture have recently appeared (JAYNES 1969, MACDANIELS 1976). Data on the elemental composition of nuts is very limited with values reported for only a few elements (LISK 1972). Several other publications have dealt with the detection of elements in various tree parts but not

A. Keith Furr; Laurence H. MacDaniels; Leigh E. St. John; Walter H. Gutenmann; Irene S. Pakkala; Donald J. Lisk

1979-01-01

194

The tree of one percent  

PubMed Central

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

Dagan, Tal; Martin, William

2006-01-01

195

Dynamic Capacitated Minimum Spanning Trees  

Microsoft Academic Search

Given a set of terminals, each associated with a positive number denoting the traffic to be routed to a central terminal (root), the Capacitated Minimum Spanning Tree (CMST) problem asks for a minimum spanning tree, spanning all terminals, such that the amount of traffic route d from a subtree, linked to the root by an edge, does not exceed the

Raja Jothi; Balaji Raghavachari

2004-01-01

196

Millersville University's Trees of Distinction  

E-print Network

-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: Nordmann fir (Abies nordmanniana) 2014-04-24 #12;#6: Southern walnut (Juglans regia) 2014-05-22 #12;#18: Female Ginkgo, Maidenhair tree (Ginkgo biloba) 2014-06-14 #12

Hardy, Christopher R.

197

Looking/Learning Drawing: Trees.  

ERIC Educational Resources Information Center

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)

Hurwitz, Al; Blume, Sharon

1985-01-01

198

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

199

Genetic conservation of native trees  

E-print Network

and implications of genetic variation within the gene-pools of British native tree species. It was acknowledged at the beginning of 2003, now cover a much wider range of British native tree species than was previously the case: 31 species relevant to forestry in Britain and 15 of these are native. The FC is a member of EUFORGEN

200

TREE FAILURES AND ACCIDENTS IN  

E-print Network

TREE FAILURES AND ACCIDENTS IN RECREATION AREAS : A Guide to Data Management for Hazard Control.DEPARTMENT O F AGRICULTURE GENERAL TECHNICAL REPORT PSW- 24 #12;TREE FAILURES AND ACCIDENTS IN RECREATION and accidents in recreation areas: A guide to data management for hazard control. Gen. Tech. Rep. PSW-24, 30 p

Standiford, Richard B.

201

Communism in trees goes underground  

NSDL National Science Digital Library

This news article reports that some trees give their neighbors carbon that they have captured from the atmosphere. Scientists discovered that shade enhances a tree's ability to receive and that carbon appears to travel via a subterranean web formed by a common group of fungi. The article concludes with references and sources (with contact information).

Strauss, E.; Online, Science N.

202

Communism in Trees Goes Underground  

NSDL National Science Digital Library

This news article reports that some trees give their neighbors carbon that they have captured from the atmosphere. Scientists discovered that shade enhances a tree's ability to receive and that carbon appears to travel via a subterranean web formed by a common group of fungi. The article concludes with references and sources (with contact information).

Strauss, Evelyn

2010-05-10

203

In Search of Moon Trees  

NSDL National Science Digital Library

In 1971, hundreds of tree seedlings germinated aboard NASA's Apollo 14 mission to the moon. A few years later, they were planted around the nation, often with much fanfare. However, no one kept a systematic record of these plantings, and as a result, the whereabouts of most of the trees remains a mystery. Visitors can read or listen to an account of the history and current status of them at this Web site, and follow links to access additional information relating to the story or to learn the location of known Moon trees. NASA scientist Dave Williams continues to search for the remaining trees and encourages readers to contact him if they believe they know of trees not currently mentioned on his list. What this site lacks in colorful, interactive features is more than made up for by its engaging feature story.

Phillips, Tony.

2002-01-01

204

A Cost Benefit Analysis of Urban Trees  

SciTech Connect

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.

Akbari, Hashem

1997-09-01

205

Packing and Hausdorff Measures of Stable Trees  

Microsoft Academic Search

\\u000a In this paper we discuss Hausdorff and packing measures of random continuous trees called stable trees. Stable trees form\\u000a a specific class of Lévy trees (introduced by Le Gall and Le Jan in [33]) that contains Aldous’s continuum random tree which\\u000a corresponds to the Brownian case. We provide results for the whole stable trees and for their level sets that

Thomas Duquesne

2010-01-01

206

Tree reconstruction from partial orders  

SciTech Connect

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.

Kannan, S.K. (Arizona Univ., Tucson, AZ (United States)); Warnow, T.J. (Sandia National Labs., Albuquerque, NM (United States))

1993-01-01

207

Tree reconstruction from partial orders  

SciTech Connect

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.

Kannan, S.K. [Arizona Univ., Tucson, AZ (United States); Warnow, T.J. [Sandia National Labs., Albuquerque, NM (United States)

1993-03-01

208

Tree preserving embedding  

PubMed Central

The goal of dimensionality reduction is to embed high-dimensional data in a low-dimensional space while preserving structure in the data relevant to exploratory data analysis such as clusters. However, existing dimensionality reduction methods often either fail to separate clusters due to the crowding problem or can only separate clusters at a single resolution. We develop a new approach to dimensionality reduction: tree preserving embedding. Our approach uses the topological notion of connectedness to separate clusters at all resolutions. We provide a formal guarantee of cluster separation for our approach that holds for finite samples. Our approach requires no parameters and can handle general types of data, making it easy to use in practice and suggesting new strategies for robust data visualization. PMID:21949369

Shieh, Albert D.; Hashimoto, Tatsunori B.; Airoldi, Edoardo M.

2011-01-01

209

Rubbery Polya Tree  

PubMed Central

Polya trees (PT) are random probability measures which can assign probability 1 to the set of continuous distributions for certain specifications of the hyperparameters. This feature distinguishes the PT from the popular Dirichlet process (DP) model which assigns probability 1 to the set of discrete distributions. However, the PT is not nearly as widely used as the DP prior. Probably the main reason is an awkward dependence of posterior inference on the choice of the partitioning subsets in the definition of the PT. We propose a generalization of the PT prior that mitigates this undesirable dependence on the partition structure, by allowing the branching probabilities to be dependent within the same level. The proposed new process is not a PT anymore. However, it is still a tail-free process and many of the prior properties remain the same as those for the PT. PMID:24368872

NIETO-BARAJAS, LUIS E.; MÜLLER, PETER

2013-01-01

210

Genetically optimized fuzzy decision trees.  

PubMed

In this study, we are concerned with genetically optimized fuzzy decision trees (G-DTs). Decision trees are fundamental architectures of machine learning, pattern recognition, and system modeling. Starting with the generic decision tree with discrete or interval-valued attributes, we develop its fuzzy set-based generalization. In this generalized structure we admit the values of the attributes that are represented by some membership functions. Such fuzzy decision trees are constructed in the setting of genetic optimization. The underlying genetic algorithm optimizes the parameters of the fuzzy sets associated with the individual nodes where they play a role of fuzzy "switches" by distributing a flow of processing completed within the tree. We discuss various forms of the fitness function that help capture the essence of the problem at hand (that could be either of classification nature when dealing with discrete outputs or regression-like when handling a continuous output variable). We quantify a nature of the generalization of the tree by studying an optimally adjusted spreads of the membership functions located at the nodes of the decision tree. A series of experiments exploiting synthetic and machine learning data is used to illustrate the performance of the G-DTs. PMID:15971931

Pedrycz, Witold; Sosnowski, Zenon A

2005-06-01

211

Tree SelectionTree Selection Why is selection important?  

E-print Network

or Dry Soil Requires Acid Soil Tolerates Neutral or Alkaline soil Tolerates Roadside or Seaside Salt of trees. #12;Make a List and Check it Twice! Some things to consider when making your plan. #12;Soil

212

Urban Tree Planting: Soil 101  

NSDL National Science Digital Library

Ever wondered how trees live amidst city sidewalks? This two-minute radio program from the show Pulse of the Planet focuses on the below-ground challenge that urban trees face--city soil. In the program, which is provided here in audio and text formats, a horticulturalist describes the importance of soil and the soil quality and quantity problems often found in cities. She then talks about a mixture that she and fellow researchers at Cornell University have developed called structural soil, which is intended to prolong urban trees' lives. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2007-11-28

213

ICE RESISTANT TREE POPULATIONS Adapted from: TREES AND ICE STORMS: THE DEVELOPMENT OF ICE STORM RESISTANT URBAN TREE  

E-print Network

branching or a broad crown that enhances ice accumulation. Many broad-leafed tree species, when grownICE RESISTANT TREE POPULATIONS Adapted from: TREES AND ICE STORMS: THE DEVELOPMENT OF ICE STORM RESISTANT URBAN TREE POPULATIONS by Richard J. Hauer, Mary C. Hruska, and Jeffrey O. Dawson. 1994

New Hampshire, University of

214

On Steiner trees and minimum spanning trees in hypergraphs  

Microsoft Academic Search

The bottleneck of the state-of-the-art algorithms for geometric Steiner problems is usually the concatenation phase, where the prevailing approach treats the generated full Steiner trees as edges of a hypergraph and uses an LP-relaxation of the minimum spanning tree in hypergraph (MSTH) problem. We study this original and some new equivalent relaxations of this problem and clarify their relations to

Tobias Polzin; Siavash Vahdati Daneshmand

2003-01-01

215

2-4 Trees and B-Trees To know what a 2-4 tree is (9.1).  

E-print Network

809 CHAPTER 9 2-4 Trees and B-Trees Objectives · To know what a 2-4 tree is (§9.1). · To design the Tree24 class that implements the Tree interface (§9.2). · To search an element in a 2-4 tree (§9.3). · To insert an element in a 2-4 tree and know how to split a node (§9.4). · To delete an element from a 2

Liang, Y. Daniel

216

Falls from trees and tree associated injuries in rural Melanesians.  

PubMed Central

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. Images FIG 1 FIG 2 FIG 3 FIG 4 PMID:6440619

Barss, P; Dakulala, P; Doolan, M

1984-01-01

217

Urban tree cover: an ecological perspective  

Microsoft Academic Search

Analysis of urban tree cover is generally limited to inventories of tree structure and composition on public lands. This approach provided valuable information for resource management. However, it does not account for all tree cover within an urban landscape, thus providing insufficient information on ecological patterns and processes. We propose evaluating tree cover for an entire urban area that is

Wayne C. Zipperer; Susan M. Sisinni; Richard V. Pouyat; Timothy W. Foresman

1997-01-01

218

How To Select and Plant a Tree.  

ERIC Educational Resources Information Center

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)…

Fazio, James R., Ed.

1991-01-01

219

Action trees and moral judgment Joshua Knobe  

E-print Network

1 Action trees and moral judgment Joshua Knobe Yale University [Forthcoming in Topics in Cognitive of an action tree. A question now arises about the relationship between this action tree representation of the action tree and then go on to use this representation in making moral judgments. The present paper argues

Knobe, Joshua

220

Dynamic Multicast Trees Jorge A. Cobb  

E-print Network

Dynamic Multicast Trees Jorge A. Cobb Department of Computer Science (EC 31) The University to build a multicast tree in a network of processes. No processing or storage overhead is required for processes not included in the tree. The overhead of processes in the tree consists solely of the periodic

Cobb, Jorge Arturo

221

Introduction Finite-State Tree Automata  

E-print Network

Introduction Finite-State Tree Automata The Complementation Problem for Automata on Innite Trees Non Deterministic Tree Automata Chapter 8 in the book, by Frank Nieÿner Presentation by Rotem Arnon Games, logic and Automata Seminar 2011 Presentation by Rotem Arnon Non Deterministic Tree Automata #12

Rabinovich, Alexander

222

Enumeration of Weighted Trees Alexander K. Zvonkin  

E-print Network

Enumeration of Weighted Trees Alexander K. Zvonkin July 16, 2013 Abstract In weighted trees, all edges are endowed with positive integral weight. We enumerate weighted bicolored plane trees according of the results are already known. However, they have their place in the context of the study of weighted trees

Zvonkin, Alexander

223

Constraint Search Trees Peter J. Stuckey  

E-print Network

Constraint Search Trees Peter J. Stuckey Department of Computer Science University of Melbourne Parkville 3052, Australia pjs@cs.mu.oz.au Abstract This paper defines constraint search trees, a general tree data structure for storing and accessing items with constraints as keys. Constraint search trees

Stuckey, Peter J.

224

A Novel Approach for Compressing Phylogenetic Trees  

E-print Network

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

Williams, Tiffani

225

The Minimum Guarding Tree Problem Adrian Dumitrescu  

E-print Network

The Minimum Guarding Tree Problem Adrian Dumitrescu Joseph S. B. Mitchell Pawel Zyli´nski September, a guarding tree for L is a tree contained in the union of the lines in L such that if a mobile guard (agent) runs on the edges of the tree, all lines in L are visited by the guard. Similarly, given a connected

Dumitrescu, Adrian

226

Learning Latent Tree Graphical Models  

E-print Network

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 ...

Choi, Myung Jin

227

Simplicial matrix-tree theorems  

E-print Network

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 ...

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

2009-01-01

228

Topic in Depth - Tree Troubles  

NSDL National Science Digital Library

This Topic in Depth explores some of the diseases and other threats, such as gypsy moths, emerald ash borers, and Asian longhorned beetles that certain trees must contend with to remain healthy and vital.

2010-09-14

229

Random ancestor trees  

NASA Astrophysics Data System (ADS)

We investigate a network growth model in which the genealogy controls the evolution. In this model, a new node selects a random target node and links either to this target node, or to its parent, or to its grandparent, etc; all nodes from the target node to its most ancient ancestor are equiprobable destinations. The emerging random ancestor tree is very shallow: the fraction gn of nodes at distance n from the root decreases super-exponentially with n, gn = e - 1/(n - 1)!. We find that a macroscopic hub at the root coexists with highly connected nodes at higher generations. The maximal degree of a node at the nth generation grows algebraically as N1/?n, where N is the system size. We obtain the series of nontrivial exponents which are roots of transcendental equations: \\beta_1\\cong 1.351\\,746 , \\beta_2\\cong 1.682\\,201 , etc. As a consequence, the fraction pk of nodes with degree k has an algebraic tail, pk ~ k - ?, with ? = ?1 + 1 = 2.351 746.

Ben-Naim, E.; Krapivsky, P. L.

2010-06-01

230

Quantum Simulation of Phylogenetic Trees  

E-print Network

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.

Demosthenes Ellinas; Peter Jarvis

2011-05-09

231

Millersville University's Trees of Distinction  

E-print Network

-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

Hardy, Christopher R.

232

If a Tree Falls in the Forest ...  

NSDL National Science Digital Library

This activity has students explore the role that forests play in their own lives by listing everyday products made from trees. They use the Internet to find as many uses for trees as possible in order to develop a class list that should include foods from trees, products derived from all parts of a tree, environmental benefits of trees, and recreational uses of trees. Students are then asked to imagine a day in their lives without trees and consider how their routine would differ and how their environment would change. This site also contains ideas for assessment and ways of extending the lesson.

233

Revised slightly from Arborist News 14 (2) 24-26, 2005. Tree Biology and Problem Trees  

E-print Network

Revised slightly from Arborist News 14 (2) 24-26, 2005. Tree Biology and Problem Trees By Kevin T. Smith, USDA Forest Service, Durham, NH 03824 USA Modern Arboriculture and Problem Trees: Have you met any problem trees? Have you created any problem trees? Can you spot them early or even prevent them

234

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

E-print Network

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

Wagner, Stephan

235

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

236

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

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

237

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

E-print Network

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

Anandkumar, Animashree

238

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

E-print Network

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

Rosenberg, Noah

239

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

240

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

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

241

ATV: display and manipulation of annotated phylogenetic trees ATV: display and manipulation of annotated phylogenetic trees  

E-print Network

ATV: display and manipulation of annotated phylogenetic trees 8/10/01 1 ATV: display and manipulation of annotated phylogenetic trees Christian M. Zmasek and Sean R. Eddy Howard Hughes Medical: {zmasek,eddy}@genetics.wustl.edu Key words: tree display, tree viewer, phylogenetic tree, java

Eddy, Sean

242

Building Cartesian Trees from Free Trees Brian C. Dean Raghuveer Mohan  

E-print Network

Building Cartesian Trees from Free Trees Brian C. Dean Raghuveer Mohan July 6, 2011 Abstract One can build a Cartesian tree from an n-element sequence in O(n) time, and from an n-node free tree in O connect these results together by describing an "adaptive" Cartesian tree construction algorithm running

Dean, Brian C.

243

reference to a tree with full foliage under local conditions (the `local tree' method). Usually this  

E-print Network

reference to a tree with full foliage under local conditions (the `local tree' method). Usually this method involves selecting the tree with the greatest amount of foliage in the general vicinity of a survey plot to serve as a standard against which the plot trees are assessed. The same local tree

244

Centennial Celebration of the Gift of Trees to Columbus, OH Cherry Tree Planting Ceremony  

E-print Network

Centennial Celebration of the Gift of Trees to Columbus, OH Cherry Tree Planting Ceremony Friday in Detroit Planting of the Cherry Blossom Trees Sakura ­ sung by Fort Hayes Arts & Academic High for students · The trees were provided by American Forests. · Pictures of Cherry Trees were provided

Jones, Michelle

245

Generic physical protection logic trees  

SciTech Connect

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.

Paulus, W.K.

1981-10-01

246

How to assemble tree machines  

NASA Astrophysics Data System (ADS)

Many researchers have proposed that ensembles of processing elements be organized as trees. This paper explores how large tree machines can be assembled efficiently from smaller components. A principal constraint considered is the limited number of external connections from an integrated circuit chip. We also explore the emerging capability of restructurable VLSI which allows a chip to be customized after fabrication. The authors give a linear-area chip of m processors and only four off-chip connections which can be used as the sole building block to construct an arbitrarily large complete binary tree. They also present a restructurable linear-area layout of m processors with O(lg m) pins that can realize an arbitrary binary tree of any size. This layout is based on a solution to the graph-theoretic problem: Given a tree in which each vertex is either black or white, determine how many edges need be cut in order to bisect the tree into equal-size components, each containing exactly half the black and half of the white vertices. These ideas extend to more general graphs using separator theorems or bifurcators.

Bhatt, S. N.; Leiserson, C. E.

1984-02-01

247

Self-adjusting binary search trees  

Microsoft Academic Search

The splay tree, a self-adjusting form of binary search tree, is developed and analyzed. The binary search tree is a data structure for representing tables and lists so that accessing, inserting, and deleting items is easy. On an n-node splay tree, all the standard search tree operations have an amortized time bound of O(log n) per operation, where by “amortized

Daniel Dominic Sleator; Robert Endre Tarjan

1985-01-01

248

Sussing Merger Trees: The Merger Trees Comparison Project  

NASA Astrophysics Data System (ADS)

Merger trees follow the growth and merger of dark-matter haloes over cosmic history. As well as giving important insights into the growth of cosmic structure in their own right, they provide an essential backbone to semi-analytic models of galaxy formation. This paper is the first in a series to arise from the Sussing Merger Trees Workshop in which 10 different tree-building algorithms were applied to the same set of halo catalogues and their results compared. Although many of these codes were similar in nature, all algorithms produced distinct results. Our main conclusions are that a useful merger-tree code should possess the following features: (i) the use of particle IDs to match haloes between snapshots; (ii) the ability to skip at least one, and preferably more, snapshots in order to recover subhaloes that are temporarily lost during merging; (iii) the ability to cope with (and ideally smooth out) large, temporary fluctuations in halo mass. Finally, to enable different groups to communicate effectively, we defined a common terminology that we used when discussing merger trees and we encourage others to adopt the same language. We also specified a minimal output format to record the results.

Srisawat, Chaichalit; Knebe, Alexander; Pearce, Frazer R.; Schneider, Aurel; Thomas, Peter A.; Behroozi, Peter; Dolag, Klaus; Elahi, Pascal J.; Han, Jiaxin; Helly, John; Jing, Yipeng; Jung, Intae; Lee, Jaehyun; Mao, Yao-Yuan; Onions, Julian; Rodriguez-Gomez, Vicente; Tweed, Dylan; Yi, Sukyoung K.

2013-11-01

249

TreeGenes: A Forest Tree Genome Database  

PubMed Central

The Dendrome Project and associated TreeGenes database serve the forest genetics research community through a curated and integrated web-based relational database. The research community is composed of approximately 2 000 members representing over 730 organizations worldwide. The database itself is composed of a wide range of genetic data from many forest trees with focused efforts on commercially important members of the Pinaceae family. The primary data types curated include species, publications, tree and DNA extraction information, genetic maps, molecular markers, ESTs, genotypic, and phenotypic data. There are currently ten main search modules or user access points within this PostgreSQL database. These access points allow users to navigate logically through the related data types. The goals of the Dendrome Project are to (1) provide a comprehensive resource for forest tree genomics data to facilitate gene discovery in related species, (2) develop interfaces that encourage the submission and integration of all genomic data, and to (3) centralize and distribute existing and novel online tools for the research community that both support and ease analysis. Recent developments have focused on increasing data content, functional annotations, data retrieval, and visualization tools. TreeGenes was developed to provide a centralized web resource with analysis and visualization tools to support data storage and exchange. PMID:18725987

Wegrzyn, Jill L.; Lee, Jennifer M.; Tearse, Brandon R.; Neale, David B.

2008-01-01

250

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

E-print Network

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

Jin, Renling

251

Genealogical trees from genetic distances  

NASA Astrophysics Data System (ADS)

In a population with haploid reproduction any individual has a single parent in the previous generation. If all genealogical distances among pairs of individuals (generations from the closest common ancestor) are known it is possible to exactly reconstruct their genealogical tree. Unfortunately, in most cases, genealogical distances are unknown and only genetic distances are available. The genetic distance between two individuals is measurable from differences in mtDNA (mitochondrial DNA) since in the case of humans or other complex organisms mtDNA is transmitted in a haploid manner. An analogous distance can be also computed for languages where it may be measured from lexical differences, in this case, nevertheless, haploid reproduction is only a raw approximation. Assuming a constant rate of mutation, these genetic distances are random and proportional only on average to genealogical ones. The reconstruction of the genealogical tree from the available genetic distances is forceful imprecise. In this paper we try to quantify the error one may commit in the reconstruction of the tree for different degrees of randomness. The errors may concern both topology of the tree (the branching hierarchy) and, in case of correct topology, the proportions of the tree (length of various branches).

Prignano, L.; Serva, M.

2009-06-01

252

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

E-print Network

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 incremental tree induction (ITI), and the other being non-incremental tree induction using a measure of tree

Massachusetts at Amherst, University of

253

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

E-print Network

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 incremental tree induction (ITI), and the other being non­incremental tree induction using a measure of tree

Massachusetts at Amherst, University of

254

Measurement of tree canopy architecture  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

255

Trees, soils, and food security  

PubMed Central

Trees have a different impact on soil properties than annual crops, because of their longer residence time, larger biomass accumulation, and longer-lasting, more extensive root systems. In natural forests nutrients are efficiently cycled with very small inputs and outputs from the system. In most agricultural systems the opposite happens. Agroforestry encompasses the continuum between these extremes, and emerging hard data is showing that successful agroforestry systems increase nutrient inputs, enhance internal flows, decrease nutrient losses and provide environmental benefits: when the competition for growth resources between the tree and the crop component is well managed. The three main determinants for overcoming rural poverty in Africa are (i) reversing soil fertility depletion, (ii) intensifying and diversifying land use with high-value products, and (iii) providing an enabling policy environment for the smallholder farming sector. Agroforestry practices can improve food production in a sustainable way through their contribution to soil fertility replenishment. The use of organic inputs as a source of biologically-fixed nitrogen, together with deep nitrate that is captured by trees, plays a major role in nitrogen replenishment. The combination of commercial phosphorus fertilizers with available organic resources may be the key to increasing and sustaining phosphorus capital. High-value trees, 'Cinderella' species, can fit in specific niches on farms, thereby making the system ecologically stable and more rewarding economically, in addition to diversifying and increasing rural incomes and improving food security. In the most heavily populated areas of East Africa, where farm size is extremely small, the number of trees on farms is increasing as farmers seek to reduce labour demands, compatible with the drift of some members of the family into the towns to earn off-farm income. Contrary to the concept that population pressure promotes deforestation, there is evidence that demonstrates that there are conditions under which increasing tree planting is occurring on farms in the tropics through successful agroforestry as human population density increases.

Sanchez, P. A.; Buresh, R. J.; Leakey, R. R. B.

1997-01-01

256

Transport of Methane in Trees  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

257

Dynamic Capacitated Minimum Spanning Trees  

E-print Network

Given a set of terminals, each associated with a positive number denoting the traffic to be routed to a central terminal (root), the Capacitated Minimum Spanning Tree (CMST) problem asks for a minimum spanning tree, spanning all terminals, such that the amount of traffic routed from a subtree, linked to the root by an edge, does not exceed the given capacity constraint k. The CMST problem is NP-complete and has been extensively studied for the past 40 years. Current best heuristics, in terms of cost and computation time (O(n log n)), are due to Esau and Williams [1], and Jothi and Raghavachari [2].

Raja Jothi; Balaji Raghavachari

2004-01-01

258

Interpreting the universal phylogenetic tree  

NASA Technical Reports Server (NTRS)

The universal phylogenetic tree not only spans all extant life, but its root and earliest branchings represent stages in the evolutionary process before modern cell types had come into being. The evolution of the cell is an interplay between vertically derived and horizontally acquired variation. Primitive cellular entities were necessarily simpler and more modular in design than are modern cells. Consequently, horizontal gene transfer early on was pervasive, dominating the evolutionary dynamic. The root of the universal phylogenetic tree represents the first stage in cellular evolution when the evolving cell became sufficiently integrated and stable to the erosive effects of horizontal gene transfer that true organismal lineages could exist.

Woese, C. R.

2000-01-01

259

Interpreting the universal phylogenetic tree  

PubMed Central

The universal phylogenetic tree not only spans all extant life, but its root and earliest branchings represent stages in the evolutionary process before modern cell types had come into being. The evolution of the cell is an interplay between vertically derived and horizontally acquired variation. Primitive cellular entities were necessarily simpler and more modular in design than are modern cells. Consequently, horizontal gene transfer early on was pervasive, dominating the evolutionary dynamic. The root of the universal phylogenetic tree represents the first stage in cellular evolution when the evolving cell became sufficiently integrated and stable to the erosive effects of horizontal gene transfer that true organismal lineages could exist. PMID:10900003

Woese, Carl R.

2000-01-01

260

The most parsimonious tree for random data.  

PubMed

Applying a method to reconstruct a phylogenetic tree from random data provides a way to detect whether that method has an inherent bias towards certain tree 'shapes'. For maximum parsimony, applied to a sequence of random 2-state data, each possible binary phylogenetic tree has exactly the same distribution for its parsimony score. Despite this pleasing and slightly surprising symmetry, some binary phylogenetic trees are more likely than others to be a most parsimonious (MP) tree for a sequence of k such characters, as we show. For k=2, and unrooted binary trees on six taxa, any tree with a caterpillar shape has a higher chance of being an MP tree than any tree with a symmetric shape. On the other hand, if we take any two binary trees, on any number of taxa, we prove that this bias between the two trees vanishes as the number of characters k grows. However, again there is a twist: MP trees on six taxa for k=2 random binary characters are more likely to have certain shapes than a uniform distribution on binary phylogenetic trees predicts. Moreover, this shape bias appears, from simulations, to be more pronounced for larger values of k. PMID:25079136

Fischer, Mareike; Galla, Michelle; Herbst, Lina; Steel, Mike

2014-11-01

261

Recursive algorithms for phylogenetic tree counting  

PubMed Central

Background In Bayesian phylogenetic inference we are interested in distributions over a space of trees. The number of trees in a tree space is an important characteristic of the space and is useful for specifying prior distributions. When all samples come from the same time point and no prior information available on divergence times, the tree counting problem is easy. However, when fossil evidence is used in the inference to constrain the tree or data are sampled serially, new tree spaces arise and counting the number of trees is more difficult. Results We describe an algorithm that is polynomial in the number of sampled individuals for counting of resolutions of a constraint tree assuming that the number of constraints is fixed. We generalise this algorithm to counting resolutions of a fully ranked constraint tree. We describe a quadratic algorithm for counting the number of possible fully ranked trees on n sampled individuals. We introduce a new type of tree, called a fully ranked tree with sampled ancestors, and describe a cubic time algorithm for counting the number of such trees on n sampled individuals. Conclusions These algorithms should be employed for Bayesian Markov chain Monte Carlo inference when fossil data are included or data are serially sampled. PMID:24164709

2013-01-01

262

Tree Height Calculator: An Android App for Estimating Tree Height  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

263

AncesTrees: ancestry estimation with randomized decision trees.  

PubMed

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

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

2014-07-23

264

Bayesian Detection in Bounded Height Tree Networks  

E-print Network

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 ...

Tay, Wee Peng

265

The Shapley value of phylogenetic trees.  

PubMed

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

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

2008-04-01

266

Asian Longhorned Beetle and its Host Trees  

E-print Network

Asian Longhorned Beetle and its Host Trees United States Department of Agriculture Forest Beetle and its Host Trees Bruce L. Parker and Margaret Skinner Entomology Research Laboratory University.........................................................................2 Description of the Asian Longhorned Beetle.......................5 Adults

Vermont, University of

267

Small Phylogeny Problem: Character Evolution Trees  

Microsoft Academic Search

Phylogenetics is a science of determining connections be- tween groups of organisms in terms of ancestor\\/descendent relationships, usually expressed by phylogenetic trees, also called \\\\trees of life\\

Arvind Gupta; Ján Manuch; Ladislav Stacho; Chenchen Zhu

2004-01-01

268

Texas Wholesale Market for Christmas Trees.  

E-print Network

Wholesale Market for 7 :. @EXAS 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...

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

1964-01-01

269

Exploring the Secret Life of Trees  

NSDL National Science Digital Library

This page, from the University of Illinois Extension, has an animated cartoon designed to help 3rd through 5th grade students gain an appreciation of trees, observe trees in their everyday lives, and develop an interest in discovering more about trees. It is intended for adults to work with children to explore the secret life of trees. It meets several of the Illinois statewide learning goals for fourth grade. The teacher's guide suggests a number of supporting activities for students.

270

A Bipolar Interpretation of Fuzzy Decision Trees  

Microsoft Academic Search

Decision tree construction is a popular approach in data mining and machine learning, and some variants of decision tree algorithms\\u000a have been proposed to deal with different types of data. In this paper, we present a bipolar interpretation of fuzzy decision\\u000a trees. With the interpretation, various types of decision trees can be represented in a unified form. The edges of

Tuan-fang Fan; Churn-jung Liau; Duen-ren Liu

2008-01-01

271

Tree Ring Data and Environmental Variables  

NSDL National Science Digital Library

This activity uses Bristlecone pine tree-ring data to understand how tree growth is related to environmental variables. It can be used to test hypotheses about how tree growth has been increasing with increasing northern hemisphere temperature in the past 100 years. This activity was originally developed by Christine Hallman and Katie Hirschboeck at the Laboratory of Tree-Ring Research at the University of Arizona. This activity is used in a Global Change course for first year non-science majors.

Bigio, Erica

272

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...

273

VACUUM TREATMENTS FOR TREE NUTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

In order to meet consumer demands and export requirements, California tree nuts (walnuts, almonds and pistachios) must be free of insect infestation. Processors have long relied on fumigants such as methyl bromide and phosphine to disinfest their product of field pests such as codling moth and nave...

274

The Tree of Animal Life  

ERIC Educational Resources Information Center

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…

Braude, Stan

2007-01-01

275

The Gift of the Tree  

NSDL National Science Digital Library

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-dep

Jones, Marla W.

2009-09-01

276

Key for Trees of Iowa.  

ERIC Educational Resources Information Center

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…

Coder, Kim D.; Wray, Paul H.

277

Electric Trees and Pond Creatures.  

ERIC Educational Resources Information Center

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)

Weaver, Helen; Hounshell, Paul B.

1978-01-01

278

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...

279

Not Just a Fall Tree  

ERIC Educational Resources Information Center

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…

Miller-Hewes, Kathy A.

2004-01-01

280

The Trees that surround us  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

281

The Gift of the Tree  

ERIC Educational Resources Information Center

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…

Jones, Marla Wagner

2009-01-01

282

Can Children Read Evolutionary Trees?  

ERIC Educational Resources Information Center

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…

Ainsworth, Shaaron; Saffer, Jessica

2013-01-01

283

The Tree of Life Project  

ERIC Educational Resources Information Center

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…

Milbrath, Sherry

2009-01-01

284

Max Ernst: "Tree of Life."  

ERIC Educational Resources Information Center

Presents a lesson plan introducing K-3 grade students to visual elements in art and the idea that artists use dreams and fantasies as subjects for their art using Max Ernst's "Tree of Life." Outlines instructional strategies and lesson objectives. (GEA)

Bray, Pam

1988-01-01

285

The Education of Little Tree.  

ERIC Educational Resources Information Center

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,…

Carter, Forrest

286

SELECTING TREES FOR HOME PLANTING.  

ERIC Educational Resources Information Center

DESIGNED FOR USE BY HIGH SCHOOL OR ADULT STUDENTS AS TEXT OR REFERENCE MATERIAL, THIS DOCUMENT PRESENTS TECHNICAL INFORMATION NEEDED IN SELECTING TREES FOR HOME PLANTING. IT WAS PREPARED BY SUBJECT MATTER SPECIALISTS, TEACHER EDUCATORS, SUPERVISORS, AND AN ADVISORY COMMITTEE OF TEACHERS. MAJOR SECTIONS ARE (1) WHAT FACTORS SHOULD I CONSIDER WHEN…

Illinois Univ., Urbana. Vocational Agriculture Service.

287

Trees of Our National Forests.  

ERIC Educational Resources Information Center

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)…

Forest Service (USDA), Washington, DC.

288

Compartmentalization of Decay in Trees.  

ERIC Educational Resources Information Center

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)

Shigo, Alex L.

1985-01-01

289

Seasonal Changes of a Tree  

NSDL National Science Digital Library

This activity is a year long project observing the changes in a specific tree. It includes using all the senses in the observation and making two different booklets to record what we observe. It also includes several picture story books that enhance the lesson.

Johnson, Karen

290

RESOVING THE GENE TREE AND SPECIES TREE PROBLEM BY PHYLOGENETIC MINING  

E-print Network

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

Wong, Limsoon

291

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

E-print Network

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

Rosenberg, Noah

292

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

ERIC Educational Resources Information Center

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…

Hollister, Sarah

293

trees.sty: A Macro for Drawing Binary or Ternary Trees  

E-print Network

trees.sty: A Macro for Drawing Binary or Ternary Trees april 1990 The following macros let you draw a (binary or ternary) tree of any size. For each will give you some ideas on designi* *ng similar things for, e.g., digital circuits. Trees

Mintmire, John W.

294

TreeDT: Tree Pattern Mining for Gene Mapping Petteri Sevon, Hannu Toivonen, and Vesa Ollikainen  

E-print Network

TreeDT: Tree Pattern Mining for Gene Mapping Petteri Sevon, Hannu Toivonen, and Vesa Ollikainen Abstract--We describe TreeDT, a novel association-based gene mapping method. Given a set of disease-associated haplotypes and a set of control haplotypes, TreeDT predicts likely locations of a disease susceptibility gene

Toivonen, Hannu

295

www.ForestConnect.com Northeastern Tree Planting & Reforestation Northeastern Tree Planting & Reforestation  

E-print Network

www.ForestConnect.com Northeastern Tree Planting & Reforestation 1 Northeastern Tree Planting;2 Northeastern Tree Planting & Reforestation www.ForestConnect.com TABLE OF CONTENTS Chapter 1 ­ Recommended homework before planting................................... 3 Chapter 2 ­ Planting trees to meet your goals

Keinan, Alon

296

Optimizing tree and character compatibility across several phylogenetic trees Simone Linza,b  

E-print Network

Optimizing tree and character compatibility across several phylogenetic trees Simone Linza, Bronx, NY, United States. Abstract Given a set R of rooted phylogenetic trees on overlapping taxa, it takes polynomial time to decide whether or not there exists a rooted phylogenetic tree

St. John, Katherine

297

High-Tech Trees: Colorado State University, recently recognized as aTree Campus USA by  

E-print Network

High-Tech Trees: Background Colorado State University, recently recognized as aTree Campus USA of Natural Resources awarded a mini-grant to a team of researchers to develop the "High-TechTrees" project in ArcGIS. Beta version of the High-Tech Trees website. Website developed using the ArcGIS Serve

298

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

E-print Network

RELATING TREE PHYSIOLOGY TO PAST AND FUTURE CHANGES IN TROPICAL RAINFOREST TREE COMMUNITIES THOMAS changes as well as a knowledge of the physiology, ecology and population biology of extant species for the regulation of tropical tree populations often invoke tree physiology or processes that are subject

Coley, Phyllis

299

Normal Spanning Trees, Aronszajn Trees and Excluded Minors Reinhard Diestel and Imre Leader  

E-print Network

Normal Spanning Trees, Aronszajn Trees and Excluded Minors Reinhard Diestel and Imre Leader We prove that a connected infinite graph has a normal spanning tree (the infinite analogue of a depth of these obstructions was needed to char- acterize the graphs with normal spanning trees. As a corollary we deduce Halin

Diestel, Reinhard

300

A survey of decision tree classifier methodology  

Microsoft Academic Search

A survey is presented of current methods for decision tree classifier (DTC) designs and the various existing issues. After considering potential advantages of DTCs over single-state classifiers, the subjects of tree structure design, feature selection at each internal node, and decision and search strategies are discussed. The relation between decision trees and neutral networks (NN) is also discussed

S. Rasoul Safavian; David Landgrebe

1991-01-01

301

Generating Production Rules from Decision Trees  

Microsoft Academic Search

Many inductive knowledge acquisition algorithms generate clas­ sifiers in the form of decision trees. This paper describes a tech­ nique for transforming such trees to small sets of production rules, a common formalism for expressing knowledge in expert systems. The method makes use of the training set of cases from which the decision tree was generated, first to generalize and

J. Ross Quinlan

1987-01-01

302

Random suffix search trees Luc Devroye1  

E-print Network

classifications. Primary: 60D05; secondary: 68U05. Key words Random binary search tree. Suffix tree. Lacunary, search engines) and strings of data (DNA strings, encrypted bit strings). For storing the dataRandom suffix search trees Luc Devroye1 and Ralph Neininger2 School of Computer Science Mc

Neininger, Ralph

303

Data multiplexer using a tree switch  

NASA Technical Reports Server (NTRS)

Self-decoding FET-hybrid or integrated-circuit tree configuration uses minimum number of components and can be sequenced by clock or computer. Redundancy features can readily be incorporated into tree configuration; as tree grows in size and more sensors are included, percentage of parts that will affect given percentage of sensors steadily decreases.

Easton, R. A.; Hilbert, E. E.

1973-01-01

304

Trees Associated with the Motzkin Numbers  

Microsoft Academic Search

. We consider plane rooted trees on n+1 vertices without branching pointson odd levels. The number of such trees in equal to the Motzkin number Mn . Wegive a bijective proof of this statement.1. Let Pn be the set of all plane rooted trees on n+1 unlabeled vertices withedges oriented from the root (see [1]). We say that a vertex

Alexander Kuznetsov; Igor Pak; Alexander Postnikov

1996-01-01

305

Where are the young Brazil nut trees?  

NSDL National Science Digital Library

If the Brazil nut industry in many Amazonian forests continues "business as usual," there will not be enough younger trees to replace the old trees as they die, according to a new study.The scientists say that important changes need to be made to the way Brazil nuts are collected in order to maintain a healthy population of nut-producing trees.

American Association for the Advancement of Science (AAAS;)

2003-12-19

306

Aronszajn Trees and the SCH Itay Neeman  

E-print Network

Aronszajn Trees and the SCH Itay Neeman and Spencer Unger February 28, 2009 1 Introduction such that the Singular Cardinal Hypothesis fails at and the tree property holds at + . The purpose of these notes. We begin with a discussion of trees, which are natural objects in infinite combinatorics. One topic

Andrews, Peter B.

307

EXCEPTIONALLY SMALL BALLS IN STABLE TREES  

E-print Network

EXCEPTIONALLY SMALL BALLS IN STABLE TREES Thomas Duquesne Guanying Wang November 14, 2011 Abstract The -stable trees are random measured compact metric spaces that appear as the scaling limit of Galton-Watson trees whose offspring distribution lies in a -stable domain, (1, 2]. They form a specific class

Paris-Sud XI, Université de

308

Large-Scale Inference of Phylogenetic Trees  

E-print Network

Large-Scale Inference of Phylogenetic Trees Alexandros Stamatakis Institute of Computer Science Trees Alexandros Stamatakis As of July 1st 2006 Swiss Institute of Bioinformatics at Lausanne #12 Tree-of-life New insights in medical & biological research #12;© Alexandros Stamatakis, March 2006 7

Poirazi, Yiota

309

Remarks about Hardy inequalities on metric trees  

E-print Network

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.

Tomas Ekholm; Rupert L. Frank; Hynek Kovarik

2007-11-13

310

On some varieties associated with trees  

E-print Network

On some varieties associated with trees F. Chapoton March 3, 2014 Abstract This article considers some affine algebraic varieties attached to finite trees and closely related to cluster algebras. Their definition involves a canonical coloring of vertices of trees into three colors. These varieties are proved

Paris-Sud XI, Université de

311

Random trees Jean-Franois Le Gall  

E-print Network

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

Le Gall, Jean-François

312

Common Intervals of Trees Steffen Heber  

E-print Network

Common Intervals of Trees Steffen Heber Dept. of Computer Science N. C. State University, Box 7566 problems, algorithms, labelled trees 1 Introduction In this paper we consider the problem of finding common intervals of trees, a general- ization of the concept of common intervals in permutations. For a permutation

Savage, Carla D.

313

Neighborhoods of Trees in Circular Orderings.  

PubMed

In phylogenetics, a common strategy used to construct an evolutionary tree for a set of species [Formula: see text] is to search in the space of all such trees for one that optimizes some given score function (such as the minimum evolution, parsimony or likelihood score). As this can be computationally intensive, it was recently proposed to restrict such searches to the set of all those trees that are compatible with some circular ordering of the set [Formula: see text]. To inform the design of efficient algorithms to perform such searches, it is therefore of interest to find bounds for the number of trees compatible with a fixed ordering in the neighborhood of a tree that is determined by certain tree operations commonly used to search for trees: the nearest neighbor interchange (NNI), the subtree prune and regraft (SPR) and the tree bisection and reconnection (TBR) operations. We show that the size of such a neighborhood of a binary tree associated with the NNI operation is independent of the tree's topology, but that this is not the case for the SPR and TBR operations. We also give tight upper and lower bounds for the size of the neighborhood of a binary tree for the SPR and TBR operations and characterize those trees for which these bounds are attained. PMID:25477080

Baskowski, Sarah; Moulton, Vincent; Spillner, Andreas; Wu, Taoyang

2014-12-01

314

Hardwood Tree Improvement and Regeneration Center  

E-print Network

. Herbicide Injury Herbicides applied for weed control can damage and even kill hardwood trees. Young trees-lethal herbicide damage usually occurs when herbicide sprays drift onto hardwood seedlings or when herbicides matter also can affect how young trees respond to herbicides. Symptoms of herbicide damage include

315

Care of Mature Backyard Apple Trees Introduction  

E-print Network

of pruning and adapt them to each tree. Pruning reduces tree size. Pruning stimulates shoot growth makes. Pruning effects are localized. Strong shoots with large leaves tend to arise at or near the site, especially near the sites where pruning cuts are made; however the overall effect is to reduce total tree

New Hampshire, University of

316

4, 28112835, 2007 The olive tree: a  

E-print Network

HESSD 4, 2811­2835, 2007 The olive tree: a paradigm for drought tolerance A. Sofo et al. Title Page are under open-access review for the journal Hydrology and Earth System Sciences The olive tree: a paradigm Correspondence to: S. Manfreda (salvatore.manfreda@unibas.it) 2811 #12;HESSD 4, 2811­2835, 2007 The olive tree

Paris-Sud XI, Université de

317

CSCI2010U Laboratory #8 Binary Trees  

E-print Network

CSCI2010U ­ Laboratory #8 Binary Trees Introduction This lab has one activity that relates to programming binary trees. To complete this lab you will need to visit the course website and download the required Lab 8 resources: · BTNode.java · BinaryTree.java · Demo.java Activity 1: Add a new method called

Bradbury, Jeremy S.

318

Higher Dimensional Trees, Algebraically Neil Ghani1  

E-print Network

Higher Dimensional Trees, Algebraically Neil Ghani1 Alexander Kurz2 1 University of Nottingham 2 papers generalising strings and trees to higher dimensions.Motivated by applications in linguistics, his goal was to smoothly extend the core theory of the formal languages of strings and trees

Ghani, Neil

319

Computational Challenges from the Tree of Life  

E-print Network

Computational Challenges from the Tree of Life Bernard M.E. Moret compbio.unm.edu Department Challenge: The Tree of Life AnimalsPurple bacteria Chlamydiae Pyrodictium Thermococcus Slime molds Aquifex Diplomonads Trichomonads Methanococcus BACTERIA EUKARYA ARCHEA ­ p. 1 #12;Scale of The Tree

Moret, Bernard

320

Computational Challenges from the Tree of Life  

E-print Network

Computational Challenges from the Tree of Life Bernard M.E. Moret compbio.unm.edu Department Tiger snake ­ p. 1 #12;The Tree of Life AnimalsPurple bacteria Chlamydiae Pyrodictium Thermococcus Slime Deinococci Aquifex Diplomonads Trichomonads Methanococcus BACTERIA EUKARYA ARCHEA ­ p. 1 #12;The Tree of Life

Moret, Bernard

321

Responses of tree populations to climatic change  

Microsoft Academic Search

The influence of climate on the population dynamics of trees must be inferred from indirect sources of information because the long lifespans of trees preclude direct observation of population growth and decline. Important insights about these processes come from 1) observations of the life histories and ecologies of trees in contemporary forests, 2) evidence of recent treeline movements in remote

Linda B. Brubaker

1986-01-01

322

Discriminating tree species using hyperspectral reflectance data  

Microsoft Academic Search

With the widely application of Remote Sensing, the request for the accuracy of classification is getting higher and higher in each application fields. The aim of this paper is to test whether spectra reflectance of various tree leaves measured under ground-level conditions contain sufficient spectral information for discriminating tree species, and finds a way to discriminate tree species from their

Yuanyong Dian; Shenghui Fang; Xiaojuan Li; Si Liang

2009-01-01

323

75 FR 25103 - Tree Assistance Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...costs to replace or rehabilitate lost or damaged trees, bushes...other. The final rule uses the words ``producer,'' ``participant...type of tree, bush, or vine lost or damaged and practice required...of the trees in the stand are lost, and normal mortality...

2010-05-07

324

Case Study: Visualizing Sets of Evolutionary Trees  

E-print Network

(e.g. the evolutionary tree for frogs) are far from clear. The most common methods for constructingCase Study: Visualizing Sets of Evolutionary Trees Nina Amenta Jeff Klingner £ University of Texas of hypothetical evolutionary trees. In- teracting with such a dataset allows the biologist to identify distinct

Amenta, Nina

325

Efficient Pythagorean trees: Greed is good  

Microsoft Academic Search

The Pythagorean tree is a fractal figure with a branching structure based upon the Pythagorean theorem. This paper describes the use of a greedy algorithm to encourage a homogenous spread of detail for asymmetrical trees and avoid localized regions of high detail. A model of prioritized branch growth based on this idea is used to optimize tree shape, allowing more

Cameron Browne

2007-01-01

326

On multicast trees: structure and size estimation  

Microsoft Academic Search

This work presents a thorough investigation of the structure of multicast trees cut from the Internet and power-law topologies. Based on both generated topologies and real Internet data, we characterize the structure of such trees and show that they obey the rank-degree power law; that most high degree tree nodes are concentrated in a low diameter neighborhood; and that the

Danny Dolev; Osnat Mokryn; Yuval Shavitt

2006-01-01

327

Thin Junction Trees Francis R. Bach  

E-print Network

Thin Junction Trees Francis R. Bach Computer Science Division University of California Berkeley, CA with thin junction trees--models that are characterized by an upper bound on the size of the maximal cliques of their triangulated graph. By ensuring that the junction tree is thin, inference in our models remains tractable

Bach, Francis

328

Thin Junction Trees Francis R. Bach  

E-print Network

Thin Junction Trees Francis R. Bach Computer Science Division University of California Berkeley, CA with thin junction trees---models that are characterized by an upper bound on the size of the maximal cliques of their triangulated graph. By ensuring that the junction tree is thin, inference in our models

Jordan, Michael I.

329

Methane Emissions from Deciduous Trees  

NASA Astrophysics Data System (ADS)

There is some disagreement today over whether terrestrial plants present a significant source of methane to the atmosphere. Even if the plants are recognized as a source, there is no clear method to extrapolate plant emissions to the global atmospheric budget of methane and estimates vary widely. There is also no consensus on a mechanism for methane production and/or plant-mediated transport to the atmosphere. Here, we present preliminary data showing a significant flux of methane to the atmosphere from three wetland deciduous tree species. Ash (Fraxinus latifolia), cottonwood (Populus deltoides L.), and willow (Salix fluviatillis) were grown in a greenhouse under inundated rice-cultivation conditions using a rice straw amendment equivalent to 3 t/ha to enhance below ground anaerobic methane production. Results of measurements of redox potential and methane concentrations in soil pore water show significant methane production similar to that observed in rice plots (Oryza sative L. 'M-103') and controls of the same treatment. Measurements of the stable carbon isotopic composition (?13C) of methane dissolved in soil pore water show no significant difference from rice plots showing no discernable difference in bulk carbon substrate. Methane flux from trees, measured using static flux chamber and bag-tree enclosures, was found to be significantly higher than control treatments (i.e., no plants) but lower than rice plants overall. The carbon isotopic composition of emitted methane from tree species was found to be approximately 8‰ enriched in ?13C compared with methane emitted from rice. This difference in ?13C of emitted methane observed between rice and trees suggests the mechanisms contributing to regulating plant-mediated methane transport (e.g. transport, oxidation, carbon sources) may be quite distinct between diverse plant functional types. Identifying the mechanistic basis of this response will be a key development towards developing more accurate estimates of methane flux over local and regional scales.

Rice, A. L.; Teama, D.; Khalil, M. K.; Shearer, M. J.; Rosenstiel, T. N.

2008-12-01

330

RECONCILED TREES 1 Submitted to Molecular Phylogeny and Evolution  

E-print Network

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

Page, Roderic

331

A PROGRAM FOR PRETTY DRAWING OF TREES Marko Bohanec  

E-print Network

DEXiTree: A PROGRAM FOR PRETTY DRAWING OF TREES Marko Bohanec Jozef Stefan Institute Jamova 39 This paper presents DEXiTree, a computer program for drawing trees. In principle, DEXiTree is aimed at making nice drawings of attribute trees made by DEXi, a computer program for qualitative multi

Bohanec, Marko

332

Parallel Construction of (a, b)trees \\Lambda  

E-print Network

Parallel Construction of (a, b)­trees \\Lambda Narsingh Deo Amit Jain Muralidhar Medidi Department. Charles, Illinois. #12; Proposed Running Head: Parallel Construction of (a, b)­trees Corresponding Author algorithm for the construction of (a, b)­trees --- a general­ ization of 2­3 trees, 2­3­4 trees, and B­trees

Jain, Amit

333

Trees 1 2004 Goodrich, Tamassia Make Money Fast!  

E-print Network

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

Alechina, Natasha

334

COMPARISON OF BARE-ROOT VERSUS TREE SPADE TRANSPLANTING OF BOULEVARD TREES  

Microsoft Academic Search

Dormant trees of green ash, black ash, hackberry and Amur cherry were transplanted along residential streets either by means of a 110 cm tree spade or bare-rooted and small trees were transplanted bare-rooted only. First season's shoot growth and leaf size of spaded trees was four to ten times larger than on comparable sized bare-rooted trees and approximately twice as

D. E. Vanstone; W. G. Ronald

1981-01-01

335

Tree height measurement protocol J Chave Page 1 Measuring tree height for tropical forest trees  

E-print Network

A field manual for the CTFS sites February 22nd 2005 Jerome Chave chave@cict.fr Lab. Evolution et-resistant, but not water-proof, so don't use it in the rain (you won't see tree tops anyway). The Nikon Laser600 come

Chave, Jérôme

336

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

E-print Network

. T. Wagonner Estate ?????????????.? 8 Climate ????????????????????.? 9 Pastures ????????????????????. 9 III THE INFLUENCE OF HONEY MESQUITE (PROSOPIS GLANDULOSA) ON THE GROWTH OF TEXAS WINTERGRASS (NASELLA LEUCOTRICHA... OF THE TREE (PROSOPIS GLANDULOSA) LAYER IN A TEMPERATE SAVANNA?????????.. 44 Introduction ??????????????????? 44 Methods ????????????????????. 47 Results ????????????????????... 48 Discussion...

Simmons, Mark Trevor

2004-11-15

337

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

E-print Network

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

New Hampshire, University of

338

Sleeping tree choice by Bwindi chimpanzees.  

PubMed

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

Stanford, Craig B; O'Malley, Robert C

2008-07-01

339

On the Hopf Algebra of Rooted Trees  

E-print Network

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.

Shouchuan Zhang; Jieqiong He; Peng Wang

2007-11-20

340

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

E-print Network

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

Jin, Renling

341

Copyright 2006 by the Tree-Ring Society 51 TREE-RING RESEARCH, Vol. 62(2), 2006, pp. 5165  

E-print Network

Copyright 2006 by the Tree-Ring Society 51 TREE-RING RESEARCH, Vol. 62(2), 2006, pp. 51­65 TREE RINGS AND THE AGING OF TREES: A CONTROVERSY IN 19TH CENTURY AMERICA CHRISTOPHER H. BRIAND Department some scientists about the validity of using tree rings to determine tree age. In an earlier boundary

Briand, Christopher

342

The DeepTree Exhibit: Visualizing the Tree of Life to Facilitate Florian Block, Michael S. Horn, Brenda Caldwell Phillips,  

E-print Network

The DeepTree Exhibit: Visualizing the Tree of Life to Facilitate Florian Block, Michael S. Horn, Brenda Caldwell Phillips, Fig. 1. The DeepTree Exhibit: main view of the tree of life, image reel present the DeepTree exhibit (cf. Fig. 1), an interactive visualization of the Tree of Life

343

Anatomical modeling of the bronchial tree  

NASA Astrophysics Data System (ADS)

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.

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

2010-02-01

344

On finding minimum-diameter clique trees  

SciTech Connect

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.

Blair, J.R.S. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science); Peyton, B.W. (Oak Ridge National Lab., TN (United States))

1991-08-01

345

Hyperdominance in the Amazonian tree flora.  

PubMed

The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community. PMID:24136971

ter Steege, Hans; Pitman, Nigel C A; Sabatier, Daniel; Baraloto, Christopher; Salomão, Rafael P; Guevara, Juan Ernesto; Phillips, Oliver L; Castilho, Carolina V; Magnusson, William E; Molino, Jean-François; Monteagudo, Abel; Núñez Vargas, Percy; Montero, Juan Carlos; Feldpausch, Ted R; Coronado, Eurídice N Honorio; Killeen, Tim J; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L; Terborgh, John; Wittmann, Florian; Andrade, Ana; Laurance, William F; Laurance, Susan G W; Marimon, Beatriz S; Marimon, Ben-Hur; Guimarães Vieira, Ima Célia; Amaral, Iêda Leão; Brienen, Roel; Castellanos, Hernán; Cárdenas López, Dairon; Duivenvoorden, Joost F; Mogollón, Hugo F; Matos, Francisca Dionízia de Almeida; Dávila, Nállarett; García-Villacorta, Roosevelt; Stevenson Diaz, Pablo Roberto; Costa, Flávia; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Montoya, Alvaro Javier Duque; Fernandez Piedade, Maria Teresa; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Gribel, Rogerio; Fine, Paul V A; Peres, Carlos A; Toledo, Marisol; Aymard C, Gerardo A; Baker, Tim R; Cerón, Carlos; Engel, Julien; Henkel, Terry W; Maas, Paul; Petronelli, Pascal; Stropp, Juliana; Zartman, Charles Eugene; Daly, Doug; Neill, David; Silveira, Marcos; Paredes, Marcos Ríos; Chave, Jerome; Lima Filho, Diógenes de Andrade; Jørgensen, Peter Møller; Fuentes, Alfredo; Schöngart, Jochen; Cornejo Valverde, Fernando; Di Fiore, Anthony; Jimenez, Eliana M; Peñuela Mora, Maria Cristina; Phillips, Juan Fernando; Rivas, Gonzalo; van Andel, Tinde R; von Hildebrand, Patricio; Hoffman, Bruce; Zent, Eglée L; Malhi, Yadvinder; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R; Silva, Natalino; Vos, Vincent; Zent, Stanford; Oliveira, Alexandre A; Schutz, Angela Cano; Gonzales, Therany; Trindade Nascimento, Marcelo; Ramirez-Angulo, Hirma; Sierra, Rodrigo; Tirado, Milton; Umaña Medina, María Natalia; van der Heijden, Geertje; Vela, César I A; Vilanova Torre, Emilio; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R; Baider, Claudia; Balslev, Henrik; Ferreira, Cid; Mesones, Italo; Torres-Lezama, Armando; Urrego Giraldo, Ligia Estela; Zagt, Roderick; Alexiades, Miguel N; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Palacios Cuenca, Walter; Pauletto, Daniela; Valderrama Sandoval, Elvis; Valenzuela Gamarra, Luis; Dexter, Kyle G; Feeley, Ken; Lopez-Gonzalez, Gabriela; Silman, Miles R

2013-10-18

346

Gene tree correction guided by orthology  

PubMed Central

Background Reconciled gene trees yield orthology and paralogy relationships between genes. This information may however contradict other information on orthology and paralogy provided by other footprints of evolution, such as conserved synteny. Results We explore a way to include external information on orthology in the process of gene tree construction. Given an initial gene tree and a set of orthology constraints on pairs of genes or on clades, we give polynomial-time algorithms for producing a modified gene tree satisfying the set of constraints, that is as close as possible to the original one according to the Robinson-Foulds distance. We assess the validity of the modifications we propose by computing the likelihood ratio between initial and modified trees according to sequence alignments on Ensembl trees, showing that often the two trees are statistically equivalent. Availability Software and data available upon request to the corresponding author. PMID:24564227

2013-01-01

347

Tree decline in North America.  

PubMed

Air-borne, phytotoxic pollutants are known to adversely affect forest tree growth in North America. On a local scale, exposure to high concentrations of toxic gases, such as sulphur dioxide and fluoride, result in foliar injury, branch dieback, reduced radial growth and increased mortality in a variety of tree species. On a regional scale, the photochemical oxidant, ozone, is responsible for growth decline of pollutant-sensitive eastern white pine genotypes in the eastern United States, and of ponderosa and Jeffrey pines in the mountains of southern and central California. The etiology associated with the reported declines of high elevation red spruce in the Appalachian Mountains and of sugar maple in the northeastern United States and southeastern Canada is incompletely known at present. A complex of predisposing and inciting factors, including temperature and moisture stress, edaphic conditions, aluminium toxicity, insect depredation, and air-borne pollutants are probably involved in these declines. PMID:15092654

Chevone, B I; Linzon, S N

1988-01-01

348

Statistical Properties of Genealogical Trees  

NASA Astrophysics Data System (ADS)

We analyze the statistical properties of genealogical trees in a neutral model of a closed population with sexual reproduction and nonoverlapping generations. By reconstructing the genealogy of an individual from the population evolution, we measure the distribution of ancestors appearing more than once in a given tree. After a transient time, the probability of repetition follows, up to a rescaling, a stationary distribution which we calculate both numerically and analytically. This distribution exhibits a universal shape with a nontrivial power law which can be understood by an exact, though simple, renormalization calculation. Some real data on human genealogy illustrate the problem, which is relevant to the study of the real degree of diversity in closed interbreeding communities.

Derrida, Bernard; Manrubia, Susanna C.; Zanette, Damián H.

1999-03-01

349

Organic & Integrated Tree Fruit Production  

NSDL National Science Digital Library

Part of the Washington State University Tree Fruit Research and Extension Center, this website offers various resources for orchardists interested in organic and integrated production methods. The site contains sections on Organic Fruit Production, Soil and Pest Management, Apple Replant Disease, and more. The site also offers links to other Washington State University sites for Horticulture, Entomology, Fruit Pathology, and Postharvest resources. Many of the documents on this site are available for download as PDF files.

350

Statistical mechanics of steiner trees.  

PubMed

The minimum weight Steiner tree (MST) is an important combinatorial optimization problem over networks that has applications in a wide range of fields. Here we discuss a general technique to translate the imposed global connectivity constrain into many local ones that can be analyzed with cavity equation techniques. This approach leads to a new optimization algorithm for MST and allows us to analyze the statistical mechanics properties of MST on random graphs of various types. PMID:18764290

Bayati, M; Borgs, C; Braunstein, A; Chayes, J; Ramezanpour, A; Zecchina, R

2008-07-18

351

Real Trees in the Classroom  

ERIC Educational Resources Information Center

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…

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

2006-01-01

352

Tree climbing and human evolution  

PubMed Central

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

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

2013-01-01

353

Functional Data Analysis of Tree Data Objects  

PubMed Central

Data analysis on non-Euclidean spaces, such as tree spaces, can be challenging. The main contribution of this paper is establishment of a connection between tree data spaces and the well developed area of Functional Data Analysis (FDA), where the data objects are curves. This connection comes through two tree representation approaches, the Dyck path representation and the branch length representation. These representations of trees in Euclidean spaces enable us to exploit the power of FDA to explore statistical properties of tree data objects. A major challenge in the analysis is the sparsity of tree branches in a sample of trees. We overcome this issue by using a tree pruning technique that focuses the analysis on important underlying population structures. This method parallels scale-space analysis in the sense that it reveals statistical properties of tree structured data over a range of scales. The effectiveness of these new approaches is demonstrated by some novel results obtained in the analysis of brain artery trees. The scale space analysis reveals a deeper relationship between structure and age. These methods are the first to find a statistically significant gender difference. PMID:25346588

Shen, Dan; Shen, Haipeng; Bhamidi, Shankar; Maldonado, Yolanda Muñoz; Kim, Yongdai; Marron, J. S.

2013-01-01

354

VC-Dimension of Univariate Decision Trees.  

PubMed

In this paper, we give and prove the lower bounds of the Vapnik-Chervonenkis (VC)-dimension of the univariate decision tree hypothesis class. The VC-dimension of the univariate decision tree depends on the VC-dimension values of its subtrees and the number of inputs. Via a search algorithm that calculates the VC-dimension of univariate decision trees exhaustively, we show that our VC-dimension bounds are tight for simple trees. To verify that the VC-dimension bounds are useful, we also use them to get VC-generalization bounds for complexity control using structural risk minimization in decision trees, i.e., pruning. Our simulation results show that structural risk minimization pruning using the VC-dimension bounds finds trees that are more accurate as those pruned using cross validation. PMID:25594983

Yildiz, Olcay Taner

2015-02-01

355

Phytoremediation of trichloroethene (TCE) using cottonwood trees  

USGS Publications Warehouse

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.

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

1999-01-01

356

Reconciliation with Non-Binary Species Trees  

PubMed Central

Abstract Reconciliation extracts information from the topological incongruence between gene and species trees to infer duplications and losses in the history of a gene family. The inferred duplication-loss histories provide valuable information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. While reconciliation for binary trees is a tractable and well studied problem, there are no algorithms for reconciliation with non-binary species trees. Yet a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and incomplete lineage sorting. We present the first algorithms for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Our algorithms utilize an efficient mapping from gene to species trees to infer the minimum number of duplications in O(|VG| · (kS + hS)) time, where |VG| is the number of nodes in the gene tree, hS is the height of the species tree and kS is the size of its largest polytomy. We present a dynamic programming algorithm which also minimizes the total number of losses. Although this algorithm is exponential in the size of the largest polytomy, it performs well in practice for polytomies with outdegree of 12 or less. We also present a heuristic which estimates the minimal number of losses in polynomial time. In empirical tests, this algorithm finds an optimal loss history 99% of the time. Our algorithms have been implemented in Notung, a robust, production quality, tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets. PMID:18808330

Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton

2008-01-01

357

Phillips goes subsea trees in Ivory Coast  

SciTech Connect

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.

Bryngelson, R.H.

1982-11-15

358

Non-Linear Decision Trees - NDT  

Microsoft Academic Search

Most decision tree algorithms focus on univariate,i.e. axis-parallel tests at each internalnode of a tree. Oblique decision treesuse multivariate linear tests at each non-leafnode. This paper reports a novel approach tothe construction of non-linear decision trees.The crux of this method consists of the generationof new features and the augmentationof the primitive features with these newones. The resulted non-linear decision treesare

Andreas Ittner; Michael Schlosser

1996-01-01

359

Alternative fire resistance strategies in savanna trees  

Microsoft Academic Search

Bark properties (mainly thickness) are usually presented as the main explanation for tree survival in intense fires. Savanna\\u000a fires are mild, frequent, and supposed to affect tree recruitment rather than adult survival: trunk profile and growth rate\\u000a of young trees between two successive fires can also affect survival. These factors and fire severity were measured on a sample\\u000a of 20

Jacques Gignoux; Jean Clobert; Jean-Claude Menaut

1997-01-01

360

Signs of Change: Studying Tree Rings  

NSDL National Science Digital Library

In this hands-on activity, students will learn about dendrochronology (the study of tree rings to understand ecological conditions in the recent past) and come up with conclusions as to what possible climatic conditions might affect tree growth in their region. Students determine the average age of the trees in their schoolyard, investigate any years of poor growth, and draw conclusions about the reasons for those years.

Colberg, Nancy; Change, Northern C.

361

On the silhouette of binary search trees  

E-print Network

A zero-one sequence describes a path through a rooted directed binary tree $T$; it also encodes a real number in $[0,1]$. We regard the level of the external node of $T$ along the path as a function on the unit interval, the silhouette of $T$. We investigate the asymptotic behavior of the resulting stochastic processes for sequences of trees that are generated by the binary search tree algorithm.

Grübel, Rudolf

2009-01-01

362

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

Reliability analysis of fault tolerant computer systems for critical applications is complicated by several factors. These modeling difficulties are discussed and dynamic fault tree modeling techniques for handling them are described and demonstrated. Several advanced fault tolerant computer systems are described, and fault tree models for their analysis are presented. HARP (Hybrid Automated Reliability Predictor) is a software package developed at Duke University and NASA Langley Research Center that is capable of solving the fault tree models presented.

Dugan, Joanne Bechta; Bavuso, Salvatore J.; Boyd, Mark A.

1993-01-01

363

Signs of Change: Studying Tree Rings  

NSDL National Science Digital Library

In this very hands-on lesson, students will learn about dendrochronology (the study of tree rings to answer ecological questions about the recent past) and come up with conclusions as to what possible climatic conditions might affect tree growth in their region. Students determine the average age of the trees in their schoolyard, investigate any years of poor growth, and draw conclusions about the reasons for the years of poor growth.

2007-01-01

364

Why are so many trees hollow?  

PubMed

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

Ruxton, Graeme D

2014-11-01

365

Tree ring record chronicles major Mesoamerican droughts  

NASA Astrophysics Data System (ADS)

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)

Tretkoff, Ernie

2011-05-01

366

Multispectral sensing of citrus young tree decline  

NASA Technical Reports Server (NTRS)

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%.

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

1975-01-01

367

The spectral dimension of generic trees  

E-print Network

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.

Bergfinnur Durhuus; Thordur Jonsson; John F. Wheater

2006-07-11

368

Tree-Structured Infinite Sparse Factor Model  

PubMed Central

A tree-structured multiplicative gamma process (TMGP) is developed, for inferring the depth of a tree-based factor-analysis model. This new model is coupled with the nested Chinese restaurant process, to nonparametrically infer the depth and width (structure) of the tree. In addition to developing the model, theoretical properties of the TMGP are addressed, and a novel MCMC sampler is developed. The structure of the inferred tree is used to learn relationships between high-dimensional data, and the model is also applied to compressive sensing and interpolation of incomplete images. PMID:25279389

Zhang, XianXing; Dunson, David B.; Carin, Lawrence

2013-01-01

369

[Potential ecological risks of transgenic trees].  

PubMed

A new approach to genetic improvement of trees has been introduced with the birth of gene engineering technique. Compared to that in crops, gene introduction in trees has bigger potential ecological risk in environmental release and extension, because trees, most of which are wind-dispersed, grow on various habitats, have longer life span, and subject to relatively more extensive management. Extensive plantation of transgenic trees may reduce the genetic diversity of the trees concerned. Co-evolution of pests and pathogens is likely to be caused under the pressure of long-term and continuous selection of the trees derived from gene transferring. Escaping of exogenous gene may have a certain kind of influence on fitness of plants naturally generated, and as a result, have influence on species diversity in the natural world. It is not reasonable for China, a developing country, to reject gene introduction as an approach to promote forestry development. It is also important, on the other hand, to take future ecological safety into consideration because it is unwise to get present profit at the cost of future profit. To strengthen basic study on gene transferring, adopting safe management of varieties generated from gene transferring and increasing funds on research and management of transgenic trees are believed to be measures to decrease, to the greatest extent, ecological risks brought about by gene transferring of trees, and to quicken transformation of products of trees derived from gene-transferring into merchandises. PMID:15506115

Kang, Xiangyang; Liu, Zhimin; Li, Shenggong

2004-07-01

370

Dendrome: Forest Tree Genome Database  

NSDL National Science Digital Library

Based in California, Dendrome is a project of the Institute of Forest Genetics (USDA Forest Service) that aims to act as "a central electronic resource for the study of forest tree genomes." Users will find a wealth of information at the site, including several excellent genome resources (complete with genetic maps), links to research institutes, upcoming scientific meetings and courses, and job opportunities. Of particular use to researchers are the genetic databases with linkage maps for numerous species of the genus Cryptomeria, Eucalyptus, Picea, Pinus and Populus. A selection of specific resources rounds out the site.

371

Can You Read a Tree?  

NSDL National Science Digital Library

In this nonfiction story, young readers and listeners learn how scientists use cross sections from trees to reconstruct past climates. Versions are provided for readers at two levels, k-2 and 3-5, and in text-only and illustrated formats. The story is also available as an electronic book with recorded narration. An original story is a regular feature of each issue of the free, online magazine Beyond Weather and the Water Cycle. The story can be used in science and literacy lessons and activities throughout the magazine.

Jessica Fries-Gaither

372

The Tree of Animal Life  

NSDL National Science Digital Library

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 groups in a general way. Though the activity doesn't teach about each animal group's characteristics in great detail, the process of sorting of atypical examples (e.g., bat, octopus) does spark interesting discussions among students on the differences between animals and how scientists classify them. I've conducted the activity with students of various ages.

Stan Braude

2007-09-01

373

Tree canopy radiance measurement system  

NASA Technical Reports Server (NTRS)

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.

Caldwell, William; Vanderbilt, V. C.

1989-01-01

374

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

PubMed

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 morefire 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. PMID:23691661

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

2013-02-01

375

The Priority R-tree: a practically efficient and worst-case optimal R-tree  

Microsoft Academic Search

We present the Priority R-tree, or PR-tree, which is the first R-tree variant that always answers a window query using O((N\\/B)1 1\\/d + T\\/B) I\\/Os, where N is the number of d-dimensional (hyper-) rectangles stored in the R-tree, B is the disk block size, and T is the output size. This is provably asymptotically optimal and significantly better than other

Lars Arge; Mark de Berg; Herman J. Haverkort; Ke Yi

2004-01-01

376

Tree rings in the tropics: a study on growth and ages of Bolivian rain forest trees  

Microsoft Academic Search

Detailed information on long-term growth rates and ages of tropical rain forest trees is important to obtain a better understanding of the functioning of tropical rain forests. Nevertheless, little is known about long-term growth or ages of tropical forest trees, due to a supposed lack of annual tree rings in most tropical tree species. Aim of this PhD thesis was

Roel Jacobus Wilhelmus Brienen

2005-01-01

377

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

SciTech Connect

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.

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

2013-04-01

378

The Trade-offs of Multicast Trees and Algorithms  

Microsoft Academic Search

Multicast trees can be shared across sources (shared trees) or may be source-specific (shortest pathtrees). Inspired by recent interests in using shared trees for interdomain multicasting, we investigate thetrade-offs among shared tree types and source specific shortest path trees, by comparing performanceover both individual multicast group and the whole network. The performance is evaluated in termsof path length, link cost,

Liming Wei; Deborah Estrin

1995-01-01

379

A congruence index for testing topological similarity between trees  

Microsoft Academic Search

Motivation: Phylogenetic trees are omnipresent in evolutionary biology and the comparison of trees plays a central role there. Tree congruence statistics are based on the null hypothesis that two given trees are not more congruent (topologically similar) than expected by chance. Usually, one searches for the most parsimonious evolu- tionary scenario relating two trees and then one tests the null

Damien M. De Vienne; Tatiana Giraud; Olivier C. Martin

2007-01-01

380

A new constrained edit distance between quotiented ordered trees  

Microsoft Academic Search

In this paper we propose a dynamic programming algorithm to compare two quo- tiented ordered trees using a constrained edit distance. An ordered tree is a tree in which the left-to-right order among siblings is significant. A quotiented ordered tree is an ordered tree T with an equivalence relation on vertices and such that, when the equivalence classes are collapsed

Aïda Ouangraoua; Pascal Ferraro

2009-01-01

381

Constructing Evolutionary/Phylogenetic Trees 2 broad categories  

E-print Network

Constructing Evolutionary/Phylogenetic Trees · 2 broad categories: ­ Distance-based methods-Distance Trees Additive distance trees are edge-weighted trees, with distance between leaf nodes are exactly 114/4/06 #12;Constructing Evolutionary/Phylogenetic Trees · 2 broad categories: ­ Distance

Narasimhan, Giri

382

Lecture 10: Minimum Spanning Trees and Prim's Algorithm  

E-print Network

Lecture 10: Minimum Spanning Trees and Prim's Algorithm CLRS Chapter 23 Outline of this Lecture . Spanning trees and minimum spanning trees. . The minimum spanning tree (MST) problem. . Prim's algorithm for the MST problem. -- The algorithm -- Correctness -- Implementation + Running Time 1 #12; Spanning Trees

Golin, Mordecai J.

383

Lecture 10: Minimum Spanning Trees and Prim's Algorithm  

E-print Network

Lecture 10: Minimum Spanning Trees and Prim's Algorithm CLRS Chapter 23 Outline of this Lecture . Spanning trees and minimum spanning trees. . The minimum spanning tree (MST) problem. . Prim's algorithm for the MST problem. -- The algorithm -- Correctness -- Implementation + Running Time 1 Spanning Trees

Golin, Mordecai J.

384

Portland State University CSAR Street Trees in the Urban Forest Canopy STREET TREES IN  

E-print Network

Portland State University ­ CSAR Street Trees in the Urban Forest Canopy STREET TREES IN THE URBAN FOREST CANOPY: PORTLAND, OREGON Project Report by Joseph Poracsky, Professor of Geography & David Banis Forest Canopy Contents ACKNOWLEDGMENTS SUMMARY Trees in the Urban Environment

Poracsky, Joseph

385

Selective limb pruning, tree removal, and paclobutrazol growth retardant for crowding pecan trees  

Microsoft Academic Search

Selective limb pruning, tree thinning, and the combination of selective limb pruning and paclobutrazol application as a basal drench were used to reduce overcrowding of pecan [Carya illinoensis (Wangenh.) C. Koch] trees. Thinning increased yield per tree for the cultivar ‘Desirable’ and did not significantly reduce yield per hectare during the 7 year period of the study. None of the

Ray E. Worley; Ben G. Mullinix; Jeff W. Daniel

1996-01-01

386

Depth of soil water uptake by tropical rainforest trees during dry periods: does tree dimension matter?  

PubMed

Though the root biomass of tropical rainforest trees is concentrated in the upper soil layers, soil water uptake by deep roots has been shown to contribute to tree transpiration. A precise evaluation of the relationship between tree dimensions and depth of water uptake would be useful in tree-based modelling approaches designed to anticipate the response of tropical rainforest ecosystems to future changes in environmental conditions. We used an innovative dual-isotope labelling approach (deuterium in surface soil and oxygen at 120-cm depth) coupled with a modelling approach to investigate the role of tree dimensions in soil water uptake in a tropical rainforest exposed to seasonal drought. We studied 65 trees of varying diameter and height and with a wide range of predawn leaf water potential (?pd) values. We confirmed that about half of the studied trees relied on soil water below 100-cm depth during dry periods. ?pd was negatively correlated with depth of water extraction and can be taken as a rough proxy of this depth. Some trees showed considerable plasticity in their depth of water uptake, exhibiting an efficient adaptive strategy for water and nutrient resource acquisition. We did not find a strong relationship between tree dimensions and depth of water uptake. While tall trees preferentially extract water from layers below 100-cm depth, shorter trees show broad variations in mean depth of water uptake. This precludes the use of tree dimensions to parameterize functional models. PMID:23852028

Stahl, Clément; Hérault, Bruno; Rossi, Vivien; Burban, Benoit; Bréchet, Claude; Bonal, Damien

2013-12-01

387

Sassafrass The Big Tree for August By Anne Krantz, Tree Steward,  

E-print Network

Big Tree Committee Last summer, I helped remeasure the Hillsborough County Champion sassafras tree country road, lined with hedgerows and thickets looking for the distinctive mitten-shaped sassafras leaves. These astonishingly tall sassafras trees, soaring to the sky, are totally unexpected this far north. New Hampshire

New Hampshire, University of

388

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

E-print Network

in 69 individuals sampled from six species of Ourisia (New Zealand native foxglove). Key wordsInferring 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

Rosenberg, Noah

389

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

ERIC Educational Resources Information Center

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…

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

390

TreeFam: a curated database of phylogenetic trees of animal gene families  

Microsoft Academic Search

TreeFam is a database of phylogenetic trees of gene families found in animals. It aims to develop a curated resource that presents the accurate evolutionary his- 20 tory of all animal gene families, as well as reliable ortholog and paralog assignments. Curated families are being added progressively, based on seed align- ments and trees in a similar fashion to Pfam.

Heng Li; Avril Coghlan; Jue Ruan; Lachlan James M. Coin; Jean-karim Hériché; Lara Osmotherly; Ruiqiang Li; Tao Liu; Zhang Zhang; Lars Bolund; Gane Ka-shu Wong; Wei-mou Zheng; Paramvir Dehal; Jun Wang; Richard Durbin

2006-01-01

391

Bioclimatic limitations on global tree distributions  

NASA Astrophysics Data System (ADS)

An important question of climate change impacts on ecosystems concerns the future global distribution of trees and forests. While models of ecosystem responses to climate change abound in the literature, there is increasing recognition that these models behave poorly when calibrated using historical data and validated using modern data. Theory predicts that the life history of an organism (ability to establish, grow, reproduce, and avoid dying) is limited by one, and only one, factor at a given location and time - the principle of limiting factors. Given that climate is a potential limitation on the distribution of forests, as are other non-climate factors such as natural and anthropogenic disturbance, soil properties, and taxonomic/evolutionary effects (when dealing with “functional types”) may be the factors limiting forests. Therefore, we take a step back from asking the question of “how does climate affect the global distribution of trees” (which is based on the assumption that climate does limit the distribution of trees) to a more basic question of “does climate limit trees globally?” To answer this, we applied boundary analysis to a fused, gridded global dataset of tree cover (derived from satellite imagery) and climate to predict the potential tree cover at a site under the assumption that the only limiting factor was climate. This potential maximum tree cover was compared to the actual tree cover at a given site to estimate the deviation between the two. We hypothesize that large deviations between the potential tree cover and actual tree cover indicate that a missing factor is present. Furthermore, we will test if one of the missing non-climate factors (fire) explains some of the deviation between potential and actual tree cover, particularly in sites hypothesized to be fire limited (e.g. savannas). We found that, contrary to assumptions many ecosystem modelers make, climate factors overpredict the tree cover by 40%: climate alone predicts a world of 60.7% tree cover, but the actual tree cover is 20.9%. Tree cover showed the smallest deviation from the climate-based potential in the world’s temperate and tropical forests, and high deviations in the world’s anthropogenic landscapes, shrublands and grasslands, and sparsely vegetated regions. By including fire frequency as a potential limiting factor in addition to the climate factors, we found that fire to be a major limiting factor in the world’s savannas. Our results suggest that climate variables are not the only factors determining the global distribution of forests, which challenges our interpretation of climate change impact models that based on these factors alone.

Greenberg, J. A.; Dobrowski, S. Z.; Santos, M.; Vanderbilt, V. C.; Ustin, S.

2010-12-01

392

The history of Newton's apple tree  

NASA Astrophysics Data System (ADS)

This article contains a brief introduction to Newton's early life to put into context the subsequent events in this narrative. It is followed by a summary of accounts of Newton's famous story of his discovery of universal gravitation which was occasioned by the fall of an apple in the year 1665/6. Evidence of Newton's friendship with a prosperous Yorkshire family who planted an apple tree arbour in the early years of the eighteenth century to celebrate his discovery is presented. A considerable amount of new and unpublished pictorial and documentary material is included relating to a particular apple tree which grew in the garden of Woolsthorpe Manor (Newton's birthplace) and which blew down in a storm before the year 1816. Evidence is then presented which describes how this tree was chosen to be the focus of Newton's account. Details of the propagation of the apple tree growing in the garden at Woolsthorpe in the early part of the last century are then discussed, and the results of a dendrochronological study of two of these trees is presented. It is then pointed out that there is considerable evidence to show that the apple tree presently growing at Woolsthorpe and known as 'Newton's apple tree' is in fact the same specimen which was identified in the middle of the eighteenth century and which may now be 350 years old. In conclusion early results from a radiocarbon dating study being carried out at the University of Oxford on core samples from the Woolsthorpe tree lend support to the contention that the present tree is one and the same as that identified as Newton's apple tree more than 200 years ago. Very recently genetic fingerprinting techniques have been used in an attempt to identify from which sources the various 'Newton apple trees' planted throughout the world originate. The tentative result of this work suggests that there are two separate varieties of apple tree in existence which have been accepted as 'the tree'. One may conclude that at least some of the current Newton apple trees have no connection with the original tree at Woolsthorpe Manor.

Keesing, R. G.

1998-05-01

393

NatioNal tree Safety Group Guidance on trees and public safety in the uK  

E-print Network

, managers and advisers Common sense risk management of trees #12;2 © Crown Copyright 2011 You may re eH12 7At. the National tree Safety Group Common sense risk management of trees Forestry Commission to owners on managing the risk from trees set out in the guidance. Common sense risk management of trees #12

394

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

SciTech Connect

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.

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

2009-07-31

395

Trees from trees: construction of phylogenetic supertrees using clann.  

PubMed

Supertree methods combine multiple phylogenetic trees to produce the overall best "supertree." They can be used to combine phylogenetic information from datasets only partially overlapping and from disparate sources (like molecular and morphological data), or to break down problems thought to be computationally intractable. Some of the longest standing phylogenetic conundrums are now being brought to light using supertree approaches. We describe the most widely used supertree methods implemented in the software program "clann" and provide a step by step tutorial for investigating phylogenetic information and reconstructing the best supertree. Clann is freely available for Windows, Mac and Unix/Linux operating systems under the GNU public licence at (http://bioinf.nuim.ie/software/clann). PMID:19378143

Creevey, Christopher J; McInerney, James O

2009-01-01

396

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

397

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

398

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

399

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

400

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

401

7 CFR 457.130 - Macadamia tree crop insurance provisions.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Macadamia tree crop insurance provisions. 457.130 Section...INSURANCE REGULATIONS § 457.130 Macadamia tree crop insurance provisions. The macadamia tree crop insurance provisions for the 2011...

2014-01-01

402

THE WIENER INDEX OF SIMPLY GENERATED RANDOM TREES  

E-print Network

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

Janson, Svante

403

7 CFR 457.130 - Macadamia tree crop insurance provisions.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Macadamia tree crop insurance provisions. 457.130 Section...INSURANCE REGULATIONS § 457.130 Macadamia tree crop insurance provisions. The macadamia tree crop insurance provisions for the 2011...

2011-01-01

404

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

405

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

406

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2012 CFR

...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...

2012-01-01

407

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2014 CFR

...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...

2014-01-01

408

7 CFR 457.130 - Macadamia tree crop insurance provisions.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Macadamia tree crop insurance provisions. 457.130 Section...INSURANCE REGULATIONS § 457.130 Macadamia tree crop insurance provisions. The macadamia tree crop insurance provisions for the 2011...

2012-01-01

409

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2011 CFR

...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...

2011-01-01

410

M______ S________ '13 Working Title: Know Your Trees!  

E-print Network

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

Snider, Barry B.

411

DISTANCE BASED METHODS IN PHYLOGENTIC TREE CONSTRUCTION CHUANG PENG  

E-print Network

DISTANCE BASED METHODS IN PHYLOGENTIC TREE CONSTRUCTION CHUANG PENG DEPARTMENT OF MATHEMATICS (weighted) trees. There are basically two types of phylogenetic methods, distance based methods finite directed graphs, directed trees and matrices. It discusses the verification of the metric property

412

NOTICE OF VACANCY Extension Tree Fruit Program Leader  

E-print Network

NOTICE OF VACANCY Extension Tree Fruit Program Leader Washington State University Search # 114569 WORKING TITLE: Extension Tree Fruit Program Leader 100% Extension OFFICIAL TITLE: Area Extension Educator State University (WSU) Tree Fruit Research and Extension Center (TFREC), Wenatchee, Washington

Collins, Gary S.

413

Classification trees with neural network feature extraction.  

PubMed

The ideal use of small multilayer nets at the decision nodes of a binary classification tree to extract nonlinear features is proposed. The nets are trained and the tree is grown using a gradient-type learning algorithm in the multiclass case. The method improves on standard classification tree design methods in that it generally produces trees with lower error rates and fewer nodes. It also reduces the problems associated with training large unstructured nets and transfers the problem of selecting the size of the net to the simpler problem of finding a tree of the right size. An efficient tree pruning algorithm is proposed for this purpose. Trees constructed with the method and the CART method are compared on a waveform recognition problem and a handwritten character recognition problem. The approach demonstrates significant decrease in error rate and tree size. It also yields comparable error rates and shorter training times than a large multilayer net trained with backpropagation on the same problems. PMID:18276489

Guo, H; Gelfand, S B

1992-01-01

414

TAX: A Tree Algebra for XML  

Microsoft Academic Search

Querying XML has been the subject of much recent investigation. A formal bulk algebra is essential for applying database-style optimization to XML queries. We develop such an algebra, called TAX (Tree Algebra for XML), for manipulating XML data, modeled as forests of labeled ordered trees. Motivated both by aesthetic considerations of intuitiveness, and by efficient computability and amenability to optimization,

H. V. Jagadish; Laks V. S. Lakshmanan; Divesh Srivastava; Keith Thompson

2001-01-01

415

A Tree Distribution for Skin Detection  

Microsoft Academic Search

Skin detection consists in detecting human skin pixels from an image. Skin detection plays an important role in various applications such as face detection, searching and filtering image content on the web. In this paper we propose a novel skin detection algorithm based on tree distribution. A tree distribution that is more general then a bayesian network, can represent a

Sanaa EL FKIHI; Mohamed DAOUDI; Driss ABOUTAJDINE

416

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...

417

Sulfur diagnostic criteria for French prune trees  

Microsoft Academic Search

One year old Marianna 2624 (Prunus cerasifera X P. munsoniana) trees grafted with French prunes (P. domestica) were grown in the greenhouse in pots containing vermiculite and supplied with graded amounts of sulfate?sulfur (SO4?S) to study the methods of evaluating sulfur (S). Tree fresh weight gain was recorded. Leaf samples were analyzed for different S fractions. Chlorophyll concentration of leaves

Izhar Ul Haq; Robert M. Carlson

1993-01-01

418

Mosses on a tree in forest habitat  

NSDL National Science Digital Library

Mosses require moisture and nutrients to grow (such as moist soil or tree bark). They anchor to tree bark with rhizoids, which are root-like structures lacking phloem and xylem. Mosses are able to lose most of their moisture without dying.

Katie Hale (California State University, Fullerton; Student, Biological Sciences)

2007-01-13

419

The "Ride for Russia" Tree Lichen Survey  

ERIC Educational Resources Information Center

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…

Young, Simon

2013-01-01

420

ForestManagement Forest and Tree Growth  

E-print Network

17 ForestManagement Forest and Tree Growth Growth and Environment Dendro-ecology Forest Growth Simulation Within the collaborative project FORSIM we adapted the distance dependent single tree forest the Departmentment of Conservation Ecology and Entomology and Prof. Hans Pretzsch from the Chair of Forest Yield

Geldenhuys, Jaco

421

Efficiently mining frequent trees in a forest  

Microsoft Academic Search

Mining frequent trees is very useful in domains like bioinformatics, web mining, mining semistructured data, and so on. We formulate the problem of mining (embedded) subtrees in a forest of rooted, labeled, and ordered trees. We present TREEMINER, a novel algorithm to discover all frequent subtrees in a forest, using a new data structure called scope-list. We contrast TREEMINER with

Mohammed Javeed Zaki

2002-01-01

422

The Arctic Tree Line and Climate Change  

E-print Network

is the Arctic Tree Line? ­ A transition zone of vegetation ­ Divides the Arctic Tundra from the Forest Photo% higher on Tundra than Forest (J.Beringer et al., 2005) - Decreasing albedo because of increase in tree cover - Causes surface heating Forest Tundra Chapin et al., (2005), 10 Nadezhda et al., (2008) Albedo

Blouin-Demers, Gabriel

423

Fast, Contention-Free Combining Tree Barriers  

E-print Network

Fast, Contention-Free Combining Tree Barriers Michael L. Scott Computer Science Department Counter-based algorithms for busy-wait barrier synchronization execute in time linear in the number] have proposed an adaptive combining tree barrier that exploits non-uniformity in inter-barrier

Scott, Michael L.

424

Deforestation: Transforming programs to eliminate trees  

E-print Network

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

Wadler, Philip

425

ANALYTIC MODELS FOR TREE COMMUNICATION PROTOCOLS  

E-print Network

to the Ethernet protocol, was to use a \\sliding" parameter Ã? whose value changes dynamically with stationsANALYTIC MODELS FOR TREE COMMUNICATION PROTOCOLS Philippe Flajolet and Philippe Jacquet INRIA, Rocquencourt 78150 Le Chesnay (France) Abstract: The tree protocol for local area networks, together

Flajolet, Philippe

426

Can America's ash trees be saved?  

E-print Network

On the Cover: The larvae of this pretty green beetle have destroyed millions of ash trees in the MidwestBeating the Beetle Can America's ash trees be saved? ResearchMICHIGAN TECHNOLOGICAL UNIVERSITY community of researchers. Their expertise ranges from invasive exotic species, such as the emerald ash borer

427

MORE BIRDS NEST IN HYBRID COTTONWOOD TREES  

Microsoft Academic Search

Natural hybrid zones can be centers of insect abundance and species richness. We investigated the possibility that this pattern may extend to other trophic levels. We found more bird nests in a cottonwood hybrid zone than in pure stands of Populus fremontii or P. angustifolia. Furthermore, within the hybrid zone, there were more nests in hybrid trees than in trees

GREGORY D. MARTINSEN; THOMAS G. WHITHAM

1994-01-01

428

PCFG models of linguistic tree representations  

Microsoft Academic Search

The kinds of tree representations used in a treebank corpus can have a dramatic effect on performance of a parser based on the PCFG estimated from that corpus, causing the estimated likelihood of a tree to differ substantially from its frequency in the training corpus. This paper points out that the Penn II treebank representations are of the kind predicted

Mark Johnson

1998-01-01

429

Signature Tree Generation for Polymorphic Worms  

E-print Network

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

Xiao, Bin

430

A Dichromatic Framework for Balanced Trees  

Microsoft Academic Search

In this paper we present a uniform framework for the implementation and study of balanced tree algorithms. We show how to imbed in this framework the best known balanced tree techniques and then use the framework to develop new algorithms which perform the update and rebalancing in one pass, on the way down towards a leaf. We conclude with a

Leonidas J. Guibas; Robert Sedgewick

1978-01-01

431

On-Line Construction of Suffix Trees  

Microsoft Academic Search

Abstract: An on-line algorithm is presented for constructing the suffix tree for a given string in time linear in the length of the string. The new algorithm has the desirable property of processing the string symbol by symbol from left to right. It has always the suffix tree for the scanned part of the string ready. The method is developed

Esko Ukkonen

1995-01-01

432

Can Landsat imagery detect tree line dynamics?  

Microsoft Academic Search

Prior research on tree line dynamics has primarily been based on field inventory data, and little is known about the potential for using remotely sensed imagery to detect change. The present study developed a new methodology by combining remote sensing and field survey data to examine dynamics of the pristine forest in the tree line area on Changbai Mountain in

Yangjian Zhang; Ming Xu; Jonathan Adams; Xiaochun Wang

2009-01-01

433

Percolation on general trees and HIV modeling  

NASA Astrophysics Data System (ADS)

Percolation on a general tree is studied. A general tree is used to model the transition from HIV infection into AIDS and to explain the large differences of the transition time from one patient to another. HIV has some autoimmune effects due to its low antigenic mutants. Fuzzy mathematics is used to explain these effects.

Ahmed, E.; Agiza, H. N.

1996-12-01

434

Tree improvement in Western conifers: economic aspects  

Microsoft Academic Search

An economic analysis is given of tree breeding programmes for improvement of ponderosa pine in the Pacific southwest and 'progressive' improvement of Douglas fir in the pacific northwest. Results suggested that these could produce a real rate of return of at least 8% if short rotations were used, or if tree improvement were accompanied by thinning. Cost\\/benefit, break-even analysis indicated

F. T. Ledig; R. L. Porterfield

1982-01-01

435

Bulk Operations for Space-Partitioning Trees  

E-print Network

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...

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

2004-01-01

436

Error Mining on Dependency Trees Claire Gardent  

E-print Network

Error Mining on Dependency Trees Claire Gardent CNRS, LORIA, UMR 7503 Vandoeuvre-l`es-Nancy, F-l`es-Nancy, F-54600, France shashi.narayan@loria.fr Abstract In recent years, error mining approaches were propose an algorithm for mining trees and ap- ply it to detect the most likely sources of gen- eration

Paris-Sud XI, Université de

437

Bag Context Tree Grammars # Sigrid Ewert  

E-print Network

Bag Context Tree Grammars # Sigrid Ewert School of Computer Science, University University S--901 87 Umeša, Sweden {drewes,johanna}@cs.umu.se Abstract. Bag context is a device for regulated or string, but evolves on its own during a derivation. Motivation for investigating bag context tree

Drewes, Frank

438

Optimal Random Matchings on Trees and Applications  

E-print Network

. In this paper we will consider tight upper- and lower-bounds on the weight of the optimal matching for random point sets distributed among the leaves of a tree, as a function of its cardinality. Specifically, given on the m leaves of -Hierarchically Separated Trees with branching factor b such that each one of its leaves

Csaba, Béla

439

Partial alphabetic trees # Arye Barkan + Haim Kaplan +  

E-print Network

with k trees, T 1 , . . . , T k , where the weights in W correspond to the leaves of F , that minimizes #12; 1 Introduction Let T be a binary tree with n leaves each associated with a weight w i # 0 2 . We a multiset of nonnegative weights W = {w 1 , . . . , w n }, partitioned into m # n blocks B 1 , . . . , Bm

Shamir, Ron

440

The Expected Additive Weight of Trees  

Microsoft Academic Search

We consider a general additive weight of random trees which depends on the structure of the subtrees, on weight functions defined on the number of internal and external nodes and on the degrees of the nodes appearing in the tree and its subtrees. Choosing particular weight functions, the corresponding weight is an important parameter appearing in the analysis of sorting

Rainer Kemp

1989-01-01

441

Social benefits of trees in urban environments  

Microsoft Academic Search

People have a behavioral need for contact with trees in cities. One cause for the increase in wilderness recreation use and popularity of indoor and outdoor gardening is a basic desire for contact with vegetation. Trees can lend cities a dimension of sensory diversity, visual order and aesthetic pleasure that is lacking. There is a relationship between levels of park

Seymour M. Gold

1976-01-01

442

'Christmas tree' created by Skylab 4 crewmembers  

NASA Technical Reports Server (NTRS)

This 'Christmas tree' was created by the three crewmen of the third manned Skylab mission aboard the space station in Earth orbit. Food cans were used to fashion the tree. This photograph was made from a television transmission made from a video tape recording on December 24, 1973.

1973-01-01

443

Recommended Trees for Plains Communities of  

E-print Network

, or their ability to spread in to native ecosystems and out-compete native species, while otherssimplydonotgrowwell tolerance · Pest resistance · Maintenance issues · Native vs. non-native species pyramidalspreading't control the weather, but we can use discernment in selecting trees to plant.Avariety of tree species

444

Apple Thinning Care of New Trees  

E-print Network

Sound of Drumming Apple Disease Update Peach Leaf Curl and Plum Pockets Raspberry Anthracnose and Cane also. Thinning is all about tradeoffs and compromise. The earlier you thin, the better the response time to assess the effect of the first application. (Hirst) Care of New Trees: If you planted new trees

Ginzel, Matthew

445

Maintaining Spanning Trees of Small Diameter  

Microsoft Academic Search

Given a graph G with m edges and n nodes, a spanning tree T of G, and an edge e that is being deleted from or inserted into G, we give efficient O(n) algorithms to compute a possible swap for e that minimizes the diameter of the new spanning tree. This problem arises in high-speed networks, particularly in optical networks.

Giuseppe F. Italiano; Rajiv Ramaswami

1994-01-01

446

Constructing Ensemble Classifiers from Expression Trees  

Microsoft Academic Search

The paper proposes and reviews a family of ensemble classifiers constructed from expression trees. Expression trees are induced using gene expression programming and cellular evolutionary algorithm. Ensemble classifiers are constructed using several techniques including majority voting, boosting and Dempster-Shafer theory of evidence. Computational experiment results confirm high quality of the proposed classifiers.

Joanna Jedrzejowicz; Piotr Jedrzejowicz

2010-01-01

447

LETTERSTO NATURE Anatolian tree ringsand the  

E-print Network

* & 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

Manning, Sturt

448

ROOT AND BUTT ROTS OF FOREST TREES  

E-print Network

ROOT AND BUTT ROTS OF FOREST TREES 12th International Conference on Root and Butt Rots IUFRO Medford, Oregon (USA) CONFERENCEPROCEEDINGS #12;ROOT AND BUTT ROTS OF FOREST TREES 12th International Conference on Root and Butt Rots IUFRO Working Party 7.02.01 CONFERENCE PROCEEDINGS M. Garbelotto & P

California at Berkeley, University of

449

Applications of Path Compression on Balanced Trees  

Microsoft Academic Search

Several fast algorithms are presented for computing functions defined on paths in trees under various assumpuons. The algorithms are based on tree mampulatton methods first used to efficiently represent equivalence relations. The algorithms have O((m + n)a(m + n, n)) running tunes, where m and n are measures of the problem size and a Is a functional reverse of Ackermann's

Robert Endre Tarjan

1979-01-01

450

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

E-print Network

serious, killing the tree. Controls for RHATB: 3. Keep trunks exposed, free of vegetation, weeds or trash Roundheaded apple-tree borer larva #12;control apple maggot, leafminers, and other pests. Backyard trees, covered in the current New England Tree Fruit Management Guide. 6. You could try mechanical "worming

New Hampshire, University of

451

Molecular basis of angiosperm tree architecture.  

PubMed

I. II. III. IV. V. References SUMMARY: 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

Hollender, Courtney A; Dardick, Chris

2014-12-01

452

Interactive Tree Of Life v2: online annotation and display of phylogenetic trees made easy.  

PubMed

Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. In addition to classical tree viewer functions, iTOL offers many novel ways of annotating trees with various additional data. Current version introduces numerous new features and greatly expands the number of supported data set types. Trees can be interactively manipulated and edited. A free personal account system is available, providing management and sharing of trees in user defined workspaces and projects. Export to various bitmap and vector graphics formats is supported. Batch access interface is available for programmatic access or inclusion of interactive trees into other web services. PMID:21470960

Letunic, Ivica; Bork, Peer

2011-07-01

453

Interactive Tree Of Life v2: online annotation and display of phylogenetic trees made easy  

PubMed Central

Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. In addition to classical tree viewer functions, iTOL offers many novel ways of annotating trees with various additional data. Current version introduces numerous new features and greatly expands the number of supported data set types. Trees can be interactively manipulated and edited. A free personal account system is available, providing management and sharing of trees in user defined workspaces and projects. Export to various bitmap and vector graphics formats is supported. Batch access interface is available for programmatic access or inclusion of interactive trees into other web services. PMID:21470960

Letunic, Ivica; Bork, Peer

2011-01-01

454

Making B+Trees Cache Conscious in Main Memory  

Microsoft Academic Search

Previous research has shown that cache behavior is im- portant for main memory index structures. Cache con- scious index structures such as Cache Sensitive Search Trees (CSS-Trees) perform lookups much faster than binary search and T-Trees. However, CSS-Trees are designed for decision support workloads with relatively static data. Although B+-Trees are more cache con- scious than binary search and T-Trees,

Jun Rao; Kenneth A. Ross

2000-01-01

455

An efficient and extensible approach for compressing phylogenetic trees  

PubMed Central

Background Biologists require new algorithms to efficiently compress and store their large collections of phylogenetic trees. Our previous work showed that TreeZip is a promising approach for compressing phylogenetic trees. In this paper, we extend our TreeZip algorithm by handling trees with weighted branches. Furthermore, by using the compressed TreeZip file as input, we have designed an extensible decompressor that can extract subcollections of trees, compute majority and strict consensus trees, and merge tree collections using set operations such as union, intersection, and set difference. Results On unweighted phylogenetic trees, TreeZip is able to compress Newick files in excess of 98%. On weighted phylogenetic trees, TreeZip is able to compress a Newick file by at least 73%. TreeZip can be combined with 7zip with little overhead, allowing space savings in excess of 99% (unweighted) and 92%(weighted). Unlike TreeZip, 7zip is not immune to branch rotations, and performs worse as the level of variability in the Newick string representation increases. Finally, since the TreeZip compressed text (TRZ) file contains all the semantic information in a collection of trees, we can easily filter and decompress a subset of trees of interest (such as the set of unique trees), or build the resulting consensus tree in a matter of seconds. We also show the ease of which set operations can be performed on TRZ files, at speeds quicker than those performed on Newick or 7zip compressed Newick files, and without loss of space savings. Conclusions TreeZip is an efficient approach for compressing large collections of phylogenetic trees. The semantic and compact nature of the TRZ file allow it to be operated upon directly and quickly, without a need to decompress the original Newick file. We believe that TreeZip will be vital for compressing and archiving trees in the biological community. PMID:22165819

2011-01-01

456

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

E-print Network

Finding the tree of life: matching phylogenetic trees to the fossil record through the 20th century of Darwin to discover the tree of life. Recent developments in systematics, such as cladistics and mol

Benton, Michael

457

75 FR 51507 - WisdomTree Asset Management, Inc., and WisdomTree Trust; Notice of Application  

Federal Register 2010, 2011, 2012, 2013, 2014

...812-13733] WisdomTree Asset Management, Inc., and WisdomTree...Applicants: WisdomTree Asset Management, Inc (``WTAM'' or...providing continuous investment management for each Fund's assets. As compensation for...

2010-08-20

458

A-3 First Tree Cutting  

NASA Technical Reports Server (NTRS)

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.

2007-01-01

459

Robins gather in a tree  

NASA Technical Reports Server (NTRS)

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.

2000-01-01

460

Three-Dimensional Imaging and Analysis of Electrical Trees.  

E-print Network

??Electrical trees are micrometre-size tubular channels of degradation in high voltage polymeric insulation, a precursor to failure of electrical power plant. Hence, electrical trees critically… (more)

Schurch Brandt, Roger

2014-01-01

461

Accumulation of PCB Congeners in Nestling Tree Swallows  

E-print Network

Accumulation of PCB Congeners in Nestling Tree Swallows (Tachycineta bicolor) on the Hudson River Sciences, Section of Ecology and Systematics, Ithaca, New York 14850 Tree swallows (Tachycineta bicolor

McCarty, John P.

462

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

E-print Network

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

Shelah, Saharon

463

Relative developmental, environmental, and tree-to-tree variability in buds from field-grown apple trees  

Microsoft Academic Search

High-throughput genomic technologies are becoming more accessible to nonmodel plant species, and therefore, tissue collected\\u000a outside controlled environments is being increasingly used for microarray analyses. In this study, we present a 15,720-feature\\u000a apple microarray analysis of the variability of gene expression in buds from field-grown apple trees. Tree-to-tree and day-to-day\\u000a variances were assessed during two different seasons: summer, when the

F. B. Pichler; E. F. Walton; M. Davy; C. Triggs; B. Janssen; J. N. Wünsche; J. Putterill; R. J. Schaffer

2007-01-01

464

Looking for trees in the forest: summary tree from posterior samples  

PubMed Central

Background Bayesian phylogenetic analysis generates a set of trees which are often condensed into a single tree representing the whole set. Many methods exist for selecting a representative topology for a set of unrooted trees, few exist for assigning branch lengths to a fixed topology, and even fewer for simultaneously setting the topology and branch lengths. However, there is very little research into locating a good representative for a set of rooted time trees like the ones obtained from a BEAST analysis. Results We empirically compare new and known methods for generating a summary tree. Some new methods are motivated by mathematical constructions such as tree metrics, while the rest employ tree concepts which work well in practice. These use more of the posterior than existing methods, which discard information not directly mapped to the chosen topology. Using results from a large number of simulations we assess the quality of a summary tree, measuring (a) how well it explains the sequence data under the model and (b) how close it is to the “truth”, i.e to the tree used to generate the sequences. Conclusions Our simulations indicate that no single method is “best”. Methods producing good divergence time estimates have poor branch lengths and lower model fit, and vice versa. Using the results presented here, a user can choose the appropriate method based on the purpose of the summary tree. PMID:24093883

2013-01-01

465

Urban Tree Effects on Soil Organic Carbon  

PubMed Central

Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ?75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C?N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered. PMID:25003872

Edmondson, Jill L.; O'Sullivan, Odhran S.; Inger, Richard; Potter, Jonathan; McHugh, Nicola; Gaston, Kevin J.; Leake, Jonathan R.

2014-01-01

466

Exploiting graph properties of game trees  

SciTech Connect

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.

Plaat, A.; Pijls, W.; Bruin, A. de [Erasmus Univ., Rotterdam (Netherlands); Schaeffer, J. [Univ. of Alberta, Edmonton, AB (Canada)

1996-12-31

467

Urban tree effects on soil organic carbon.  

PubMed

Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ?75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C?N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered. PMID:25003872

Edmondson, Jill L; O'Sullivan, Odhran S; Inger, Richard; Potter, Jonathan; McHugh, Nicola; Gaston, Kevin J; Leake, Jonathan R

2014-01-01

468

Mechanical Stimuli Regulate the Allocation of Biomass in Trees: Demonstration with Young Prunus avium Trees  

PubMed Central

Background and Aims Plastic tree-shelters are increasingly used to protect tree seedlings against browsing animals and herbicide drifts. The biomass allocation in young seedlings of deciduous trees is highly disturbed by common plastic tree-shelters, resulting in poor root systems and reduced diameter growth of the trunk. The shelters have been improved by creating chimney-effect ventilation with holes drilled at the bottom, resulting in stimulated trunk diameter growth, but the root deficit has remained unchanged. An experiment was set up to elucidate the mechanisms behind the poor root growth of sheltered Prunus avium trees. Methods Tree seedlings were grown either in natural windy conditions or in tree-shelters. Mechanical wind stimuli were suppressed in ten unsheltered trees by staking. Mechanical stimuli (bending) of the stem were applied in ten sheltered trees using an original mechanical device. Key Results Sheltered trees suffered from poor root growth, but sheltered bent trees largely recovered, showing that mechano-sensing is an important mechanism governing C allocation and the shoot–root balance. The use of a few artificial mechanical stimuli increased the biomass allocation towards the roots, as did natural wind sway. It was demonstrated that there was an acclimation of plants to the imposed strain. Conclusions This study suggests that if mechanical stimuli are used to control plant growth, they should be applied at low frequency in order to be most effective. The impact on the functional equilibrium hypothesis that is used in many tree growth models is discussed. The consequence of the lack of mechanical stimuli should be incorporated in tree growth models when applied to environments protected from the wind (e.g. greenhouses, dense forests). PMID:18448448

Coutand, Catherine; Dupraz, Christian; Jaouen, Gaëlle; Ploquin, Stéphane; Adam, Boris

2008-01-01

469

Comprehensive Decision Tree Models in Bioinformatics  

PubMed Central

Purpose Classification is an important and widely used machine learning technique in bioinformatics. Researchers and other end-users of machine learning software often prefer to work with comprehensible models where knowledge extraction and explanation of reasoning behind the classification model are possible. Methods This paper presents an extension to an existing machine learning environment and a study on visual tuning of decision tree classifiers. The motivation for this research comes from the need to build effective and easily interpretable decision tree models by so called one-button data mining approach where no parameter tuning is needed. To avoid bias in classification, no classification performance measure is used during the tuning of the model that is constrained exclusively by the dimensions of the produced decision tree. Results The proposed visual tuning of decision trees was evaluated on 40 datasets containing classical machine learning problems and 31 datasets from the field of bioinformatics. Although we did not expected significant differences in classification performance, the results demonstrate a significant increase of accuracy in less complex visually tuned decision trees. In contrast to classical machine learning benchmarking datasets, we observe higher accuracy gains in bioinformatics datasets. Additionally, a user study was carried out to confirm the assumption that the tree tuning times are significantly lower for the proposed method in comparison to manual tuning of the decision tree. Conclusions The empirical results demonstrate that by building simple models constrained by predefined visual boundaries, one not only achieves good comprehensibility, but also very good classification performance that does not differ from usually more complex models built using default settings of the classical decision tree algorithm. In addition, our study demonstrates the suitability of visually tuned decision trees for datasets with binary class attributes and a high number of possibly redundant attributes that are very common in bioinformatics. PMID:22479449

Stiglic, Gregor; Kocbek, Simon; Pernek, Igor; Kokol, Peter

2012-01-01

470

Tree Death Study's Climate Change Connections  

SciTech Connect

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.

McDowell, Nate

2012-09-10

471

Photosynthesis, Trees, and the Greenhouse Effect  

NSDL National Science Digital Library

In this lesson plan students will study photosynthesis and then transfer their understanding of this topic to a consideration of how trees can help reduce the negative impacts of the greenhouse effect. They will read a webpage describing the greenhouse effect, the role of carbon dioxide as a greenhouse gas, and the role of humans in exacerbating this effect. Students will also browse the website of an organization that sponsors tree planting programs and consider how these programs might help reduce or slow down the increase of the greenhouse effect. They will conclude by writing paragraphs telling younger kids about the benefits of trees and plants.

472

Tree Death Study's Climate Change Connections  

ScienceCinema

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.

McDowell, Nate

2014-06-25

473

Chlorinated ethenes from groundwater in tree trunks  

USGS Publications Warehouse

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.

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

1999-01-01

474

Algorithms for optimal dyadic decision trees  

SciTech Connect

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.

Hush, Don [Los Alamos National Laboratory; Porter, Reid [Los Alamos National Laboratory

2009-01-01

475

The decision tree approach to classification  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

476

IND - THE IND DECISION TREE PACKAGE  

NASA Technical Reports Server (NTRS)

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.

Buntine, W.

1994-01-01

477

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

PubMed Central

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

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

2014-01-01

478

Big tree : have you ever seen a tree big enough to drive a car through?  

NSDL National Science Digital Library

In this activity, students are given the girth and height of 10 National Champion giant trees and asked to determine which of the trees is large enough for a car to drive through. The activity, from the Figure This! list of 80 math challenges, also asks students to apply what they have learned to estimate the height of a tree in their neighborhood. It suggests that the student make a table to relate information about tree girth, circumference, and diameter to help determine which giant trees are big enough for a car to drive through. The importance of measurement formulas to careers in biology, construction, and publishing is noted. The page features links to a solution hint, the solution, related math questions, and resources for learning more about trees. Copyright 2005 Eisenhower National Clearinghouse

Engineering, National A.; National Council of Teachers of Mathematics (NCTM); Communications, Widmeyer

2002-01-01

479

Top-Down Tree Edit-Distance of Regular Tree Languages  

E-print Network

,11,21] and one of the most well-known measures is is the Levenshtein distance [11], which is often calledTop-Down Tree Edit-Distance of Regular Tree Languages Sang-Ki Ko1 , Yo-Sub Han1 , and Kai Salomaa2, Ontario K7L 3N6, Canada ksalomaa@cs.queensu.ca Abstract. We study the edit-distance of regular tree

Han, Yo-Sub

480

The Fractional Prize-Collecting Steiner Tree Problem on Trees: Extended Abstract  

Microsoft Academic Search

We consider the fractional prize-collecting Steiner tree problem on trees. This problem asks for a subtree T containing the root of a given tree G = (V;E) max- imizing the ratio of the vertex profits v2V (T) p(v) and the edge costs e2E(T) c(e) plus a fixed cost c0 and arises in energy supply management. We experimentally com- pare three

Gunnar W. Klau; Ivana Ljubic; Petra Mutzel; Ulrich Pferschy; René Weiskircher

2003-01-01

481

Depicting the Tree of Life: the Philosophical and Historical Roots of Evolutionary Tree Diagrams  

Microsoft Academic Search

It is a popularly held view that Darwin was the first author to draw a phylogenetic tree diagram. However, as is the case\\u000a with most popular beliefs, this one also does not hold true. Firstly, Darwin never called his diagram of common descent a\\u000a tree. Secondly, even before Darwin, tree diagrams were used by a variety of philosophical, religious, and

Nathalie Gontier

482

APPLICATION OF TREE-RING ISOTOPIC ANALYSES TO RECONSTRUCT HISTORICAL WATER USE OF RIPARIAN TREES  

Microsoft Academic Search

Historical patterns of water source use by trees inferred from long-term records of tree-ring stable isotopic content could assist in evaluating the impact of human alterations to natural stream flow regimes (e.g., water impoundments, stream flow diversions, and groundwater extraction). Our objective was to assess the utility of the hydrogen stable isotopic composition (dD) of tree rings as an index

Karrin P. Alstad; Stephen C. Hart; Jonathan L. Horton; Thomas E. Kolb

2008-01-01

483

TreePlus: Interactive Exploration of Networks with Enhanced Tree Layouts  

Microsoft Academic Search

Despite extensive research, it is still difficult to produce effective interactive layouts for large graphs. Dense layout and occlusion make food webs, ontologies, and social networks difficult to understand and interact with. We propose a new interactive Visual Analytics component called TreePlus that is based on a tree-style layout. TreePlus reveals the missing graph structure with visualization and interaction while

Bongshin Lee; Cynthia Sims Parr; Catherine Plaisant; Benjamin B. Bederson; Vladislav Daniel Veksler; Wayne D. Gray; Christopher Kotfila

2006-01-01

484

On Postnikov's Hook Length Formula for Binary Trees  

E-print Network

On Postnikov's Hook Length Formula for Binary Trees William Y.C. Chen1 and Laura L.M. Yang2 Center@hotmail.com Abstract. We present a combinatorial proof of Postnikov's hook length formula for binary trees. AMS Classification: 05A15, 05A19 Keywords: Binary tree, labeled tree, Postnikov's hook length formula Corresponding

Chen, Bill

485

BORER DAMAGE IN GREEN ASH TREES FROM DIFFERENT PROVENANCES  

Microsoft Academic Search

Young trees of green ash (Fraxlnus pennsyivanica) from 43 geographic origins throughout the species' range were heavily attacked (81 %) by the ash borer (Podosesia syringae) or its sibling species P. aureoclncta, with no differences among provenances. Faster growing trees were attacked more often than weak trees. The few fast- growing, borer-free trees remaining are being vegetatively propagated and used

Frank S. Santamour; Kim C. Steiner

1986-01-01

486

Regular networks can be uniquely constructed from their trees  

E-print Network

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

Willson, Stephen J.

487

On the re-rooting invariance property of Levy trees  

E-print Network

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

Le Gall, Jean-François

488

Inclusion Constraints over Non-empty Sets of Trees?  

E-print Network

Inclusion Constraints over Non-empty Sets of Trees? Martin Muller1, Joachim Niehren1 and Andreas of trees. The existing systems of set constraints can express INES con- straints only if they include of trees. In this paper we focus on sets of possibly in nite trees. All given results can be easily adapted

Paris-Sud XI, Université de

489

Exploiting Thread-Level Parallelism to Build Decision Trees  

E-print Network

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

Minnesota, University of

490

Learning random logdepth decision trees under the uniform distribution  

E-print Network

Learning random log­depth decision trees under the uniform distribution Je#rey C. Jackson.harvard.edu November 30, 2004 Abstract We consider three natural models of random logarithmic depth decision trees over . The learning algorithm constructs a decision tree as its hypothesis. Keywords: PAC learning, decision trees

Servedio, Rocco

491

The Asymptotic Number of Leftist Trees Michael Drmota  

E-print Network

(T ) is the number of leaves, for example) such that F consists of all trees with weight !(T ) > 0 of leaves in leftist trees of with n nodes satis#12;es a central limit theorem. 1 Introduction Let T denote. Finally, L(T ) denotes the set of leaves of T . A rooted ordered tree T is called leftist tree if for all

Drmota, Michael

492

A Stepwise Algorithm for Finding Minimum Evolution Trees Sudhir Kumar  

E-print Network

A Stepwise Algorithm for Finding Minimum Evolution Trees Sudhir Kumar Institute of Molecular for reconstructing minimum evolution (ME) trees from evolutionary distance data is proposed. In each step, a taxon and then its true neighbor searched iteratively. For m taxa, at most (m - 1)!/2 trees are examined and the tree

Kumar, Sudhir

493

CandidTree: Visualizing Structural Uncertainty in Similar Hierarchies  

E-print Network

CandidTree: Visualizing Structural Uncertainty in Similar Hierarchies Bongshin Lee1 , George G hierarchies, we interpreted the differences between two tree structures as uncertainty. We developed a new interactive visualization system called CandidTree that merges two trees into one and visualizes two types

Golbeck, Jennifer

494

Compositions of Tree Series Transformations Andreas Maletti 1,  

E-print Network

Compositions of Tree Series Transformations Andreas Maletti 1, Dresden University of Technology Department of Computer Science D­01062 Dresden, Germany Abstract Tree series transformations computed by bottom-up and top-down tree series trans- ducers are called bottom-up and top-down tree series

Reyle, Uwe

495

Finding the Wood by the Trees Marc van Kreveld  

E-print Network

Finding the Wood by the Trees Marc van Kreveld Abstract We'll give a strategy to locate all trees points from a starting tree using a rope, navigation equipment, computation, and some memory. 1 Introduction It is a well-known fact that it is sometimes di cult to see the wood for the trees. In this note

Utrecht, Universiteit

496

Week 2: Searching for trees, ancestral states January, 2010  

E-print Network

Week 2: Searching for trees, ancestral states Genome 570 January, 2010 Week 2: Searching for trees, ancestral states ­ p.1/52 #12;Greedy search for a maximum If start here Week 2: Searching for trees, ancestral states ­ p.2/52 #12;Greedy search for a maximum If start here Week 2: Searching for trees

Borenstein, Elhanan

497

Phylogenetic trees & orthology Fritz-Laylin et al. cell 2010  

E-print Network

3/6/2013 1 Phylogenetic trees & orthology #12;Fritz-Laylin et al. cell 2010 ·Med11 vs kinases: orthology ·Trees are useful beyond that: HGT, timing of duplication, study of all kinds of evolutionary processes #12;Gene Trees, Gene Duplications, and Orthology · How to make trees · Bootstrap · Interpreting

Utrecht, Universiteit

498

Introduction to Artificial Intelligence Problem Space and Search Tree  

E-print Network

Introduction to Artificial Intelligence (G51IAI) Dr Rong Qu Problem Space and Search Tree #12;G51IAI ­ Search Space & Tree Trees Nodes Root node Children/parent of nodes Leaves Branches Average branching factor average number of branches of the nodes in the tree JB C D E F G A H I #12;G51IAI ­ Search

Qu, Rong

499

Tree Isomorphism: An Exercise in Functional Programming Jayadev Misra  

E-print Network

Tree Isomorphism: An Exercise in Functional Programming Jayadev Misra 9/10/01 1 Problem Description The problem is to decide if two unordered trees are the same. More precisely, define a binary relation isomorphic over non-empty trees by the following rules. 1. A tree with a single node (the root) is isomorphic

Misra, Jayadev

500

Weighted parsing of trees Mark-Jan Nederhof  

E-print Network

Weighted parsing of trees Mark-Jan Nederhof School of Computer Science, University of St Andrews North Haugh, St Andrews, KY16 9SX, Scotland Abstract We show how parsing of trees can be for- malized in terms of the intersection of two tree languages. The focus is on weighted regular tree grammars

Nederhof, Mark-Jan