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1

Trace metals in soil and leaves of Jacaranda mimosifolia in Tshwane area, South Africa  

NASA Astrophysics Data System (ADS)

Plant and soil have been identified as major sink of pollutants in the environment. We evaluated the reliability of biomonitoring of heavy metals in Tshwane area with the use of leaves of Jacaranda mimosifolia. The concentrations of heavy metals such as Ca, Mg, Fe, Pb, Zn, Cu, Sb were measured in leaves of J. mimosifolia and soils collected from 10 sites in the city of Tshwane during two sampling periods. The metals were analyzed with the use of ICP-MS. The result shows significant differences in the concentration of trace metals in all the sites ( p < 0.01). The differences between the two sampling periods were statistically significant ( p < 0.01). Concentration of metals from high traffic and industrial sites were significantly higher than in the residential areas ( p < 0.01). Concentration factor suggests that translocation of metals from roots to leaves could be relevant only for some metals such as Ca, Mg and Sb. The study reveals an anthropogenic source for the trace metals. Leaves of J. mimosifolia were found to be a useful biomonitor of the determined trace metals.

Olowoyo, J. O.; van Heerden, E.; Fischer, J. L.; Baker, C.

2010-05-01

2

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

3

Eight variable microsatellite loci for a Neotropical tree, Jacaranda copaia (Aubl.) D.Don (Bignoniaceae).  

PubMed

The Dendrogene Project (Genetic Conservation within Managed Forests in Amazonia) aims to understand the genetic and ecological processes that underpin tree species survival and in particular their response to forest management regimes. As part of the project, we developed eight microsatellite markers for Jacaranda copaia to be used for genetic structure, gene flow and reproductive biology studies. Polymorphism was evaluated using 96 adult trees from the Tapajos National Forest in the Eastern Brazilian Amazon. An average of 22 alleles per locus were detected, with expected heterozygosity ranging from 0.731 to 0.94. PMID:21586023

Vinson, C C; Sampaio, I; Ciampi, A Y

2008-11-01

4

Phenylpropanoids from the stem bark of Jacaranda mimosaefolia.  

PubMed

Two new compounds: 2-(3',4'-dihydroxyphenyl) ethyl-3-O-?-L-rhamnopyranosyl-4-O-p-hydroxyphenylacetyl-6-O-caffeoyl-?-D-glucopyranoside and 2-(3',4'-dihydroxyphenyl) ethyl-3-O-?-L-rhamnopyranosyl-4-O-piperidine-3-carboxylic acid-6-O-caffeoyl-?-D-glucopyranoside were isolated from the stem bark of Jacaranda mimosaefolia. In addition, the known compounds lupeol, betulinaldehyde, terminic acid, betulinic acid, maslinic acid, ?-sitosterol glucoside and isoacteoside were isolated and identified. PMID:21240764

Zaghloul, A M; Gohar, A A; Ahmad, M M; Baraka, H N; El-Bassuony, A A

2011-01-01

5

Pollination Biology of Jacaranda oxyphylla with an Emphasis on Staminode Function  

PubMed Central

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

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

2008-01-01

6

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

7

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

E-print Network

entitled: "Structure of the Mitochondrial genome of Ganoderma species". Pretoria is known as the "Jakaranda or more of the species in the genus Ganoderma. These fungi survive either as pathogens or saprophytes in the past, G. applinatum and G. lucidum. It is thus possible that one of these species, or a yet undescribed

8

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.

9

Genetic diversity in natural populations of Jacaranda decurrens Cham. determined using RAPD and AFLP markers  

PubMed Central

Jacaranda decurrens (Bignoniaceae) is an endemic species of the Cerrado with validated antitumoral activity. The genetic diversity of six populations of J. decurrens located in the State of São Paulo was determined in this study by using molecular markers for randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP). Following optimization of the amplification reaction, 10 selected primers generated 78 reproducible RAPD fragments that were mostly (69.2%) polymorphic. Two hundred and five reproducible AFLP fragments were generated by using four selected primer combinations; 46.3% of these fragments were polymorphic, indicating a considerable level of genetic diversity. Analysis of molecular variance (AMOVA) using these two groups of markers indicated that variability was strongly structured amongst populations. The unweighted pair group method with arithmatic mean (UPGMA) and Pearson's correlation coefficient (RAPD -0.16, p = 0.2082; AFLP 0.37, p = 0.1006) between genetic matrices and geographic distances suggested that the population structure followed an island model in which a single population of infinite size gave rise to the current populations of J. decurrens, independently of their spatial position. The results of this study indicate that RAPD and AFLP markers were similarly efficient in measuring the genetic variability amongst natural populations of J. decurrens. These data may be useful for developing strategies for the preservation of this medicinal species in the Cerrado. PMID:21637428

2010-01-01

10

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

11

Subacute and Reproductive Oral Toxicity Assessment of the Hydroethanolic Extract of Jacaranda decurrens Roots in Adult Male Rats  

PubMed Central

Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença (Bignoniaceae) is a species traditionally used for the treatment of inflammatory and infectious diseases. Previous findings from our group reported scientifically that J. decurrens has anti-inflammatory efficacy. However, more toxicological studies are needed to support and ensure its safe use. The present study was carried out to evaluate the toxic effects of a prolonged treatment with hydroethanolic root extract of J. decurrens (EJD) on hematological, biochemical, and reproductive parameters in adult male rats. The animals received by oral gavage 0; 250; 500; or 1000?mg/kg body weight of EJD for 28 days. After the treatment, biochemical, hematological, histopathological, and reproductive parameters were analyzed. The EJD treatment did not cause adverse effects on body weight gain, feed and water consumption, hematological and biochemical profiles, or histopathological analysis of liver and kidney. Similarly, there were no statistically significant differences in reproductive parameters, such as sperm production, number of sperm in the epididymis, and sperm morphology. These results demonstrate the absence of subacute toxicity as a result of the oral treatment with EJD for 28 days in adult male rats. However, other studies should be performed to evaluate the total safety of this plant. PMID:24348699

Santos, Joyce Alencar; Arruda, Aline; Cardoso, Claudia Andrea Lima; Vieira, Maria do Carmo; Piccinelli, Ana Cláudia; Figueiredo de Santana Aquino, Diana; Kassuya, Cândida Aparecida Leite; Arena, Arielle Cristina

2013-01-01

12

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

13

Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections  

Microsoft Academic Search

BACKGROUND: The antimicrobial activity and Minimal Inhibitory Concentration (MIC) of the extracts of Bidens pilosa L., Bixa orellana L., Cecropia peltata L., Cinchona officinalis L., Gliricidia sepium H.B. & K, Jacaranda mimosifolia D.Don, Justicia secunda Vahl., Piper pulchrum C.DC, P. paniculata L. and Spilanthes americana Hieron were evaluated against five bacteria (Staphylococcus aureus, Streptococcus ? hemolític, Bacillus cereus, Pseudomonas aeruginosa,

Jhon J Rojas; Veronica J Ochoa; Saul A Ocampo; John F Muñoz

2006-01-01

14

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

15

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.)

Lawrence Hall of Science

1982-01-01

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

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

Chen, Tsuhan

18

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

19

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

20

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

21

INCREASING TREE FAMILIES Michael Drmota  

E-print Network

INCREASING TREE FAMILIES Michael Drmota Inst. of Discrete Mathematics and Geometry Vienna · Recursive Trees · Plane Oriented Trees · General Increasing Trees · Degree Distribution · Conclusion #12;Recursive Trees #12;Recursive Trees #12;Recursive Trees #12;Recursive Trees #12;Recursive Trees #12

Drmota, Michael

22

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

23

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.

S. Rosen

2010-01-01

24

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

25

Inferring trees.  

PubMed

Molecular phylogenetics examines how biological sequences evolve and the historical relationships between them. An important aspect of many such studies is the estimation of a phylogenetic tree, which explicitly describes evolutionary relationships between the sequences. This chapter provides an introduction to evolutionary trees and some commonly used inferential methodology, focusing on the assumptions made and how they affect an analysis. Detailed discussion is also provided about some common algorithms used for phylogenetic tree estimation. Finally, there are a few practical guidelines, including how to combine multiple software packages to improve inference, and a comparison between Bayesian and maximum likelihood phylogenetics. PMID:18566770

Whelan, Simon

2008-01-01

26

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

27

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

28

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

29

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

30

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.

31

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.

32

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

33

Community Trees Community Tree Steward Program  

E-print Network

-sized shade tree, yet in many urban sites, trees are routinely confined to tree pits that provide a paltry 401 Community Trees Community Tree Steward Program ...and justice for all The U.S. Department environmental requirements for plant growth include adequate space for root and canopy development, sufficient

Koford, Rolf R.

34

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

35

Christmas Tree  

NSDL National Science Digital Library

Last year, the front page of the Christmas Day New York Times talked about how you could do `finger xmastree@cygnus.com' to find out the current state of the Christmas tree in the offices of Cygnus Support. Well, it's back again this year. But, we wouldn't want you to be bored! "Oh, ho hum, that same boring thing all over again...been there, saw that." So to follow the example of a few million enthusiasts, the increasingly-popular World Wide Web is now toting its very own Christmas tree, which is so interactive it's almost like it's in your home. (Well, not quite. But if you'd like to send some wrapped gifts, I'm sure we wouldn't be upset.) Along with getting to look at a small photo of the tree when you first connect to it, you may: choose to see a full-size version of that picture -- they are updated every two minutes; choose to watch an MPEG movie of the tree which is 20 frames long, so you can watch the lights blink, etc. This is updated every fifteen minutes; vote on the different features of the tree, and every fifteen minutes the system will do the vote count and change the tree accordingly; send any one of ten random cards to a given email address; find out the technical details of how it was done, if you're really that interested. If you have any comments, suggestions, or complaints (come to think of it, you can keep the complaints), write to

36

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

37

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 ...

38

Urban tree mortality  

E-print Network

for managing the urban canopy, in terms of tree removal andurban tree planting initiatives, these trees must survive to maturity, when canopyurban forest programs. Fifteen percent would like researchers to provide accurate estimates of tree mortality, growth, and canopy

Roman, Lara Angelica

2013-01-01

39

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

40

Technical Tree Climbing.  

ERIC Educational Resources Information Center

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

Jenkins, Peter

41

13 C nuclear magnetic resonance spectroscopic analysis of seed oils containing conjugated unsaturated acids  

Microsoft Academic Search

13C Nuclear magnetic resonance spectroscopy has been used in a nondestructive investigation of conjugated unsaturated acids\\u000a in seed oil triacylglycerols. Spectra of seven seed oils, fromPunica granatum, Cucurbita palmata, Jacaranda mimosifolia, Centranthus ruber, Catalpa bignonioides, Chilopsis linearis andCalendula officinalis, containing among them six isomeric trienoic acids,cis,trans,cis- andtrans,trans,cis-8,10,12-,cis,trans,cis-, cis,trans,trans-, trans,trans,cis- andtrans,trans,trans-9,11,13-octadecatrienoic acids, and of the oil ofImpatiens balsamina containingcis,trans,trans,cis-9,11,13,15-octadecatetraenoic acid, have

A. P. Tulloch

1982-01-01

42

Tree Link  

NSDL National Science Digital Library

This site was created to provide information, research, and networking for people working in urban and community forestry. It is meant to inform, educate, and inspire the researcher, arborist, community group leader, and volunteer. The site contains: educational materials, how-to guides, a research database, discussion forums, a quarterly web-zine, a comprehensive link list of national and local resources, late-breaking news, interactive tools for tree identification and selection, and an Ask an Arborist section.

43

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

44

What Makes a Tree a Tree?  

ERIC Educational Resources Information Center

Provides: (1) background information on trees, focusing on the parts of trees and how they differ from other plants; (2) eight activities; and (3) ready-to-copy pages dealing with tree identification and tree rings. Activities include objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. (JN)

NatureScope, 1986

1986-01-01

45

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

46

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.

47

Ancient trees in Amazonia  

Microsoft Academic Search

The ages of tropical rain forest trees provide critical information for understanding the dynamics of tree populations, determining historical patterns of disturbance, developing sustainable forestry practices and calculating carbon cycling rates. Nevertheless, the ecological life history of most tropical trees is unknown and even the ages of the largest trees remain to be determined. Tree ages are typically measured by

Jeffrey Q. Chambers; Niro Higuchi; Joshua P. Schimel

1998-01-01

48

The Tree Worker's Manual.  

ERIC Educational Resources Information Center

This manual is designed to prepare students for entry-level positions as tree care professionals. Addressed in the individual chapters of the guide are the following topics: the tree service industry; clothing, eqiupment, and tools; tree workers; basic tree anatomy; techniques of pruning; procedures for climbing and working in the tree; aerial…

Smithyman, S. J.

49

Tea Tree Oil  

MedlinePLUS

... Services National Institutes of Health Search NIH…Turning Discovery Into Health ® Follow NCCAM: Read our disclaimer about external links Read our disclaimer about external links Menu Tea Tree Oil Common Names: Australian tea tree oil, tea tree ...

50

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.

51

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.

2008-08-25

52

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.

53

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

54

Structure i-Tree Tree Eco Overview  

E-print Network

The Davey InstituteHow do we communicate the value of the resource at risk? Evanston has over 4,000 ash trees on its parkways and in its parks, which is about 12 % of the City of Evanston’s 33,000 public trees. Evanston resource at risk to EAB 3500 ash street trees 10.5 % of public trees $3.18 million structural value 4.9 million gal/yr of rainfall intercepted worth $135,000/yr $122,000/yr energy savings $20,350/yr in air quality improvement $113,000 annual CO2 valueCan you justify your needsIncreasing Public Scrutinyi-Tree Tree Backgroundi-Tree Tree Includes…

Urban Forest; Al Zelaya; Urban Forest; Canopy Loss; Ufore Assessing Urban Ecosystems

55

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

56

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

57

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

58

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

59

Minimum Spanning Tree Jayadev Misra  

E-print Network

Minimum Spanning Tree Jayadev Misra 12/12/98 1 Spanning Tree A spanning tree of an undirected graph for finding the minimum spanning tree. Properties of spanning trees In a spanning tree: · There is no cycle edges have non-negative weights. A minimum span- ning tree is a spanning tree whose total edge weight

Misra, Jayadev

60

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

61

Additive similarity trees  

Microsoft Academic Search

Similarity data can be represented by additive trees. In this model, objects are represented by the external nodes of a tree, and the dissimilarity between objects is the length of the path joining them. The additive tree is less restrictive than the ultrametric tree, commonly known as the hierarchical clustering scheme. The two representations are characterized and compared. A computer

Shmuel Sattath; Amos Tversky

1977-01-01

62

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

63

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

64

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

65

Categorizing ideas about trees: a tree of trees.  

PubMed

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

66

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

67

Water treeing in polyethylene cables  

Microsoft Academic Search

Water tree growth in polyethylene cable insulation is discussed. The characteristics of water trees, the effect of aging parameters on water tree growth, and the possible mechanisms of growth are considered, emphasizing vented tree development in polyethylene insulating materials. The morphology of water trees, the characteristics of the tree-infested dielectric cable, and test methods and measures to reduce water treeing

E. F. Steennis; F. H. Kreuger

1990-01-01

68

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

69

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

70

Tree Decline Shade trees often gradually lose  

E-print Network

observed in the aboveground parts of the plant usually begin in the root system. Stress Factors Trees conditions, and other environmental effects. These are often called "stress factors" and alone or collectively reduce growth and may cause dieback of the tree. The root system is espe- cially vulnerable

71

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

72

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

73

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

74

Pine tree forest  

NSDL National Science Digital Library

The pine tree demonstrates the differences among gymnosperms and bryophytes and seedless vascular plants. Pine trees have separate cones with pollen and ovulates. Wind blows the pollen onto the ovulate cone and seeds are produced.

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

2007-01-13

75

Grizzly Giant Tree  

USGS Multimedia Gallery

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

76

Tree SelectionTree Selection Why is selection important?  

E-print Network

Tree SelectionTree Selection #12; Why is selection important? What happens when we think it's not important? Not all trees grow alike Incompatible situation Average life span of city tree is 7-13 years end up with a tree in the wrong location. #12;Tree Selection Style I Let's Try Another Selection

77

Minimum Spanning Tree What is a Minimum Spanning Tree.  

E-print Network

Minimum Spanning Tree · What is a Minimum Spanning Tree. · Constructing Minimum Spanning Trees. · What is a Minimum-Cost Spanning Tree. · Applications of Minimum Cost Spanning Trees. · Prim's Algorithm;What is a Minimum Spanning Tree. · Let G = (V, E) be a simple, connected, undirected graph

Razak, Saquib

78

Balancing Minimum Spanning Trees and Shortest-Path Trees  

Microsoft Academic Search

We give a simple algorithm to find a spanning tree that simultaneously approximates a shortest-path tree and a minimum spanning tree. The algorithm provides a continuous tradeoff: given the two trees and a 7 > 0, the algorithm returns a spanning tree in which the distance between any vertex and the root of the shortest-path tree is at most 1

Samir Khuller; Balaji Raghavachari; Neal E. Young

1995-01-01

79

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.

80

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

81

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.

University of Nebraska State Museum

2001-01-01

82

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.

83

Symbolic Tree Transducers  

Microsoft Academic Search

Symbolic transducers are useful in the context of web security as they form the foundation for sanitization of potentially malicious data. We define Symbolic Tree Transducers as a generalization of Regular Transducers as finite state input-output tree automata with logical constraints over a parametric background theory. We examine key closure properties of Symbolic Tree Transducers and we develop a composition

Margus Veanes; Nikolaj Bjorner

2011-01-01

84

Overprvning Large Decision Trees  

Microsoft Academic Search

This paper presents empirical evidence for five hypotheses about learning from large noisy domains: that trees built from very large training sets are larger and more accurate than trees built from even large subsets; that this increased accuracy is only in part due to the extra size of the trees; and that the extra training instances allow both better choices

Jason Catlett

1991-01-01

85

Marrying Words and Trees  

Microsoft Academic Search

Traditionally, data that has both linear and hierarchical structure, such as annotated linguistic data, is modeled us- ing ordered trees and queried using tree automata. In this paper, we argue that nested words and automata over nested words oer a better way to capture and process the dual structure. Nested words generalize both words and ordered trees, and allow both

Rajeev Alur

2007-01-01

86

Multiclass Alternating Decision Trees  

Microsoft Academic Search

The alternating decision tree (ADTree) is a successful clas- sication technique that combines decision trees with the predictive ac- curacy of boosting into a set of interpretable classication rules. The original formulation of the tree induction algorithm restricted atten- tion to binary classication problems. This paper empirically evaluates several wrapper methods for extending the algorithm to the multiclass case by

Geoffrey Holmes; Bernhard Pfahringer; Richard Kirkby; Eibe Frank; Mark Hall

2002-01-01

87

Representing Trees with Constraints   

E-print Network

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

Curry, Benjamin; Wiggins, Geraint; Hayes, Gillian

88

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

89

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

90

Fault Tree Analysis  

Microsoft Academic Search

In this chapter, a state-of-the-art review of fault tree analysis is presented. Different forms of fault trees, including\\u000a static, dynamic, and non-coherent fault trees, their applications and analyses will be discussed. Some advanced topics such\\u000a as importance analysis, dependent failures, disjoint events, and multistate systems will also be presented.

Liudong Xing; Suprasad V. Amari

91

Sharing A Labeled Tree  

Microsoft Academic Search

This paper introduces a way to share a labeled tree. For sharing a labeled tree, the Prufer code or a Prufer-like code of the tree is evaluated. Then, the terms of this code are modified by a function introduced to make shares, so that every term of the code can be deter- mined if and only if all the shares

Yasser A. Phoulady; Mahdi Behzadi; Hassan Taheri

92

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.

93

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.

94

RECURSIVE TREES Michael Drmota  

E-print Network

copies of ancient texts · convex hull algorithms · ... #12;Enumeration of Recursive Trees All recursiveRECURSIVE TREES Michael Drmota Institue of Discrete Mathematics and Geometry Vienna University School on GROWTH AND SHAPES, Paris, IHP, June 2­6, 2008 #12;Contents · Combinatorics on Recursive Trees

Drmota, Michael

95

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

96

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

97

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

98

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

99

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

100

Balancing Minimum Spanning Trees and ShortestPath Trees  

E-print Network

Balancing Minimum Spanning Trees and Shortest­Path Trees Samir Khuller \\Lambda University and a minimum spanning tree. The algorithm provides a continuous trade­off: given the two trees and a fl ? 0 is at most 1 + p 2=fl times the weight of a minimum spanning tree. Our algorithm runs in linear time

Khuller, Samir

101

SIMPLY GENERATED TREES, CONDITIONED GALTONWATSON TREES, RANDOM ALLOCATIONS  

E-print Network

SIMPLY GENERATED TREES, CONDITIONED GALTON­WATSON TREES, RANDOM ALLOCATIONS AND CONDENSATION: EXTENDED ABSTRACT SVANTE JANSON 1. Simply generated trees and Galton­Watson trees We suppose that we nodes v in T, where d+(v) is the outdegree of v. Trees with such weights are called simply generated

Janson, Svante

102

SIMPLY GENERATED TREES, CONDITIONED GALTON--WATSON TREES, RANDOM ALLOCATIONS  

E-print Network

SIMPLY GENERATED TREES, CONDITIONED GALTON--WATSON TREES, RANDOM ALLOCATIONS AND CONDENSATION: EXTENDED ABSTRACT SVANTE JANSON 1. Simply generated trees and Galton--Watson trees We suppose that we of a finite rooted and ordered (a.k.a. plane) tree T by w(T ) := # v#T w d + (v) , (1.1) taking the product

Janson, Svante

103

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

104

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

105

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

106

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 find that for any species tree topology with five or more species, there exist branch lengths for which

Degnan, James

107

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

108

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

109

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.

110

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 Fran�§oise 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.

111

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 ...

112

Recursively Imputed Survival Trees  

PubMed Central

We propose recursively imputed survival tree (RIST) regression for right-censored data. This new nonparametric regression procedure uses a novel recursive imputation approach combined with extremely randomized trees that allows significantly better use of censored data than previous tree based methods, yielding improved model fit and reduced prediction error. The proposed method can also be viewed as a type of Monte Carlo EM algorithm which generates extra diversity in the tree-based fitting process. Simulation studies and data analyses demonstrate the superior performance of RIST compared to previous methods. PMID:23125470

Zhu, Ruoqing; Kosorok, Michael R.

2011-01-01

113

Species integrity in trees.  

PubMed

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

Ortiz-Barrientos, Daniel; Baack, Eric J

2014-09-01

114

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

115

MUNICIPAL TREE PROGRAMS IN PENNSYLVANIA  

Microsoft Academic Search

Municipal tree programs were assessed in Pennsylvania through mail surveys. Pennsylvania has ap- proximately 378 tree programs of which 57% are implemented thrqugh shade tree commissions. Only 28% of Pennsylvania's citiqs and boroughs have tree programs. A high level of tree health exists in only 27% of the cities with programs. Only 28% of the programs have streettree inventories. Numbers

Eric C. Reeder; Henry D. Gerhold

1988-01-01

116

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.

American Forests

117

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

118

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

119

Balancing Minimum Spanning Trees and Shortest-Path Trees  

Microsoft Academic Search

We give a simple algorithm to find a spanning tree that simultaneously approxi- mates a shortest-path tree and a minimum spanning tree. The algorithm provides a continuous trade-off: given the two trees and a > 0, the algorithm returns a span- ning tree in which the distance between any vertex and the root of the shortest-path tree is at most

Samir Khuller; Penn State

1993-01-01

120

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

E-print Network

Tree height measurement protocol ­ J Chave Page 1 Measuring tree height for tropical forest trees Diversité Biologique Université Paul Sabatier 31000 Toulouse, France 1. Introduction Tree height is a fundamental geometrical variable for trees. Unfortunately, most measures are based on visual inspection

Chave, Jérôme

121

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

E-print Network

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

New Hampshire, University of

122

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.

123

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

124

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

125

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.

126

Oriented trees in digraphs  

E-print Network

Let f(k) be the smallest integer such that every f(k)-chromatic digraph contains every oriented tree of order k. Burr proved that f(k) ? (k?1) 2 and conjectured f(k) = 2n?2. In this paper, we give some sufficient conditions for an n-chromatic digraphs to contains some oriented tree. In particular

Louigi Addario-berry; Frédéric Havet; Cláudia Linhares Sales; Bruce Reed; Stéphan Thomassé

2011-01-01

127

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.

Suzanne K. Werner

2003-03-01

128

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

129

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

130

Trees From Helicopters  

NSDL National Science Digital Library

This story is aimed at promoting not only inquiry into the germination of tree seeds but seeing trees as typical flowering plants, also known as angiosperms. There is also ample opportunity to take an excursion into fruits and seeds and the germination of

Richard Konicek-Moran

2008-04-01

131

Probabilistic Timed Behavior Trees  

Microsoft Academic Search

The Behavior Tree notation has been developed as a method for systematically and traceably capturing user requirements. In this paper we extend the notation with probabilistic behaviour, so that relia- bility, performance, and other dependability properties can be expressed. The semantics of probabilistic timed Behavior Trees is given by mapping them to probabilistic timed automata. We gain advantages for require-

Robert Colvin; Lars Grunske; Kirsten Winter

2007-01-01

132

CSI for Trees  

NSDL National Science Digital Library

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 e

Darrin L. Rubino

2009-10-01

133

Trees in Our Lives.  

ERIC Educational Resources Information Center

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

NatureScope, 1986

1986-01-01

134

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

135

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

136

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

137

Climate change & street trees project  

E-print Network

Climate change & street trees project Social Research Report The social and cultural values, and governance, of street trees Norman Dandy March 2010 #12;Contents Summary .................................................................................................4 1.1 What is a `street tree

138

Verticillium Wilt of Shade Trees  

E-print Network

Ginkgo Mountain ash Walnut Hackberry Mulberry Willow Hawthorn Oak Yew Hickory Pawpaw Zelkova Verticillium Sassafras Boxwood Horse chestnut Serviceberry Brambles Japanese pagoda tree Smoke tree Buckeye Lilac Sumac

139

Ash Tree Identification Key Ash Tree Characteristics  

E-print Network

berries Walnut, Hickory, Mountain-Ash: alternate branching #12;Identifying Emerald Ash Borer what to do if you think you have the ash-killing Emerald Ash Borer (EAB) in your ash tree Verify the signs of EAB: 1/8" "D" shaped "S" shaped tunnels small, 3/4" metallic green beetles 1/8 D shaped exit holes

Walter, M.Todd

140

Language trees not equal gene trees.  

PubMed

Darwin saw similarities between the evolution of species and the evolution of languages, and it is now widely accepted that similarities between related languages can often be interpreted in terms of a bifurcating descent history ('phylogenesis'). Such interpretations are supported when the distributions of shared and unshared traits (for example, in terms of etymological roots for elements of basic vocabulary) are analysed using tree-building techniques and found to be well-explained by a phylogenetic model. In this article, we question the demographic assumption which is sometimes made when a tree-building approach has been taken to a set of cultures or languages, namely that the resulting tree is also representative of a bifurcating population history. Using historical census data relating to Gaelic- and English-speaking inhabitants of Sutherland (Highland Scotland), we have explored the dynamics of language death due to language shift, representing the extreme case of lack of congruence between the genetic and the culture-historical processes. Such cases highlight the important role of selective cultural migration (or shifting between branches) in determining the extinction rates of different languages on such trees. PMID:20532998

Steele, James; Kandler, Anne

2010-09-01

141

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.

Randall Jones

1999-09-17

142

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

E-print Network

­ p.11/40 #12;A consensus subtree F C A B G DFCA BDE F AB D E Week 10: Consensus trees, tree distances, tests of tree shape ­ p.12/40 #12;A consensus subtree F C A B G DFCA BDE F AB D E Week 10: Consensus trees, tree distances, tests of tree shape ­ p.13/40 #12;A consensus subtree F C A B G DFCA BDE F AB D E

Borenstein, Elhanan

143

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

144

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

145

Global Trees Campaign  

NSDL National Science Digital Library

Along with increasing concerns about the extinction of different animal species, there has been increased interest in monitoring the fate of plant species, particularly those of various trees. Drawing on a partnership between Flora & Fauna International and the UNEP World Conservation Monitoring Centre, the Global Trees Campaign Web site serves as an online conduit for information about endangered tree species. First-time visitors will want to read the various tree profiles along the right-hand side of the homepage. Some of the species covered here include the African blackwood, Honduras rosewood, and the monkey puzzle tree, which grows naturally in Chile and Argentina. The resources section of the site is also worth a look, as it contains a database with information on close to 7,300 tree species, and list of suggested readings -- including several that are available as PDF files. For those interested in the projects initiated by the Global Trees Campaign, a section detailing their various initiatives around the globe is also available for consultation.

146

Phylogenetic trees in bioinformatics  

SciTech Connect

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

Burr, Tom L [Los Alamos National Laboratory

2008-01-01

147

44 TREE CARE INDUSTRY -MARCH 2002 Tree&Landscape  

E-print Network

44 TREE CARE INDUSTRY - MARCH 2002 Tree&Landscape 44 II nstallation of underground irrigation green in more ways than one. From keeping trees healthy to providing a viable source of income to their clients. Improved soil con- ditions for tree growth can be achieved using irrigation, and state

Schweik, Charles M.

148

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

149

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

150

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

151

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

152

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

153

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 and from species trees. Surprisingly, assuming that genetic lineages follow a coalescent model of within

Rosenberg, Noah

154

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

155

Discordance of Species Trees with Their Most Likely Gene Trees  

Microsoft Academic Search

Because of the stochastic way in which lineages sort during speciation, gene trees may differ in topology from each other and from species trees. Surprisingly, assuming that genetic lineages follow a coalescent model of within-species evolution, we find that for any species tree topology with five or more species, there exist branch lengths for which gene tree discordance is so

James H. Degnan; Noah A. Rosenberg

2006-01-01

156

Peach Tree Pruning.  

E-print Network

removes the terminal portion of shoots, stimulates regrowth near the cut and is the most invigorating type of cut. It induces branching at spe cific points such as establishing scaffolds in young trees. However, heading has the greatest effect... are small to reduce regrowth. Train scaffolds to a 45? angle in the early years to minimize the need for severe bench cuts later (figure 2). Pruning Newly Set Trees Prune newly planted trees immediately after plant ing. Use a heading cut 24 to 30...

Lyons, Calvin G.

1986-01-01

157

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.

158

Evolutionary tree reconstruction  

NASA Technical Reports Server (NTRS)

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

Cheeseman, Peter; Kanefsky, Bob

1990-01-01

159

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

160

TreeBase  

NSDL National Science Digital Library

TreeBase (last mentioned in the October 30, 1998 Scout Report) is a database of phylogenetic information sponsored by Harvard University Herbaria, Leiden University EEW, and the University of California, Davis. The site stores phylogenetic trees and the data matrices used to generate them from published research papers and currently includes 1098 authors, 614 studies, 1704 trees, and 21456 taxa (roughly three times more data than the Scout Report first review in 1998). The searchable database takes a little time getting used to, but the resulting information is valuable.

161

Minimum spanning trees for tree metrics: abridgements and adjustments  

Microsoft Academic Search

Two properties of tree metrics are already known in the literature: tree metrics on a setX withn elements have 2n?3 degrees of freedom; a tree metric has Robinson form with regard to its minimum spanning tree (MST), or to any such MST\\u000a if several of them exist. Starting from these results, we prove that a tree metrict is entirely defined

Bruno Leclerc

1995-01-01

162

Structural Equation Model Trees  

PubMed Central

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

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

2015-01-01

163

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

164

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

165

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

166

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.

167

Tree-bank grammars  

SciTech Connect

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

Charniak, E. [Brown Univ., Providence, RI (United States)

1996-12-31

168

Generalized constructive tree weights  

NASA Astrophysics Data System (ADS)

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; Tanasa, Adrian

2014-04-01

169

Life of a Tree  

NSDL National Science Digital Library

In this interactive activity adapted from the National Arbor Day Foundation, take a sixty-two-year journey observing the inner layers, rings, and environmental factors that affect a tree's growth and life cycle.

2007-08-09

170

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

171

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

172

Planar Bichromatic Minimum Spanning Trees  

E-print Network

Planar Bichromatic Minimum Spanning Trees Magdalene G. Borgelt Marc van Kreveld Maarten L Bichromatic Minimum Spanning Trees Magdalene G. Borgelt1 Marc van Kreveld2 Maarten L¨offler2 Jun Luo2 Damian points in the plane, a planar bichromatic minimum spanning tree is the shortest possible spanning tree

Utrecht, Universiteit

173

The Minimum Labeling Spanning Trees  

Microsoft Academic Search

One of the fundamental problems in graph theory is to compute a minimum weight spanning tree. In this paper, a variant of spanning trees, called the minimum labeling spanning tree, is studied. The purpose is to find a spanning tree that tries to use edges that are as similar as possible. Giving each edge a label, the minimum labeling spanning

Ruay-Shiung Chang; Shing-jiuan Leu

1997-01-01

174

State Trees and Arbor Days.  

ERIC Educational Resources Information Center

Provides information on state trees for each of the 50 states and the District of Columbia. Includes for each state: (1) year in which state tree was chosen; (2) common and scientific names of the tree; (3) arbor day observance; (4) address of state forester; and (5) drawings of the tree, leaf, and fruit or cone. (JN)

Forest Service (USDA), Washington, DC.

175

Quantum computation and decision trees  

Microsoft Academic Search

Many interesting computational problems can be reformulated in terms of decision trees. A natural classical algorithm is to then run a random walk on the tree, starting at the root, to see if the tree contains a node n level from the root. We devise a quantum-mechanical algorithm that evolves a state, initially localized at the root, through the tree.

Edward Farhi; Sam Gutmann

1998-01-01

176

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

177

Carbon Sequestration in Campus Trees  

NSDL National Science Digital Library

In this activity, students use a spreadsheet to calculate the net carbon sequestration in a set of trees; they will utilize an allometric approach based upon parameters measured on the individual trees. They determine the species of trees in the set, measure trunk diameter at a particular height, and use the spreadsheet to calculate carbon content of the tree using forestry research data.

Robert S. Cole

178

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

179

How Trees Can Save Energy.  

ERIC Educational Resources Information Center

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

Fazio, James R., Ed.

1991-01-01

180

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.

181

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

182

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

183

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

184

Tree manipulation experiment  

NASA Astrophysics Data System (ADS)

Some forest operations such as thinning and harvesting management could cause changes in N cycling and N2O emission from soils, since thinning and harvesting managements are accompanied with changes in aboveground environments such as an increase of slash falling and solar radiation on the forest floor. However, a considerable uncertainty exists in effects of thinning and harvesting on N2O fluxes regarding changes in belowground environments by cutting trees. To focus on the effect of changes in belowground environments on the N2O emissions from soils, we conducted a tree manipulation experiment in Japanese cedar (Cryptomeria japonica) stand without soil compaction and slash falling near the chambers and measured N2O flux at 50 cm and 150 cm distances from the tree trunk (stump) before and after cutting. We targeted 5 trees for the manipulation and established the measurement chambers to the 4 directions around each targeted tree relative to upper slope (upper, left, right, lower positions). We evaluated the effect of logging on the emission by using hierarchical Bayesian model. HB model can evaluate the variability in observed data and their uncertainties in the estimation with various probability distributions. Moreover, the HB model can easily accommodate the non-linear relationship among the N2O emissions and the environmental factors, and explicitly take non-independent data (nested structure of data) for the estimation into account by using random effects in the model. Our results showed tree cutting stimulated N2O emission from soils, and also that the increase of N2O flux depended on the distance from the trunk (stump): the increase of N2O flux at 50 cm from the trunk (stump) was greater than that of 150 cm from the trunk. The posterior simulation of the HB model indicated that the stimulation of N2O emission by tree cut- ting could reach up to 200 cm in our experimental plot. By tree cutting, the estimated N2O emission at 0-40 cm from the trunk doubled (the % increase of N2O emission; 54% to 213%; 95% C.I.) condition when soil temperature was 25oC and WFPS was 60%. The posterior simulation of the model estimated that 10% logging caused a 20% (15% to 24%; 95% CI) increase N2O emission in our study site (2000 trees ha-1) for the only tree cutting effects during the measurement period (about 160 day). On the basis of our findings, the belowground environmental changes by logging management would considerably contribute the stimulation of N2O emission.

Nishina, K.; Takenaka, C.; Ishizuka, S.; Hashimoto, S.; Yagai, Y.

2012-12-01

185

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

186

The inference of gene trees with species trees.  

PubMed

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

187

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

188

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

189

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

190

Tree Rings: Timekeepers of the Past.  

ERIC Educational Resources Information Center

One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree

Phipps, R. L.; McGowan, J.

191

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

192

Predictive Classification Trees  

NASA Astrophysics Data System (ADS)

CART (Breiman et al., Classification and Regression Trees, Chapman and Hall, New York, 1984) and (exhaustive) CHAID (Kass, Appl Stat 29:119-127, 1980) figure prominently among the procedures actually used in data based management, etc. CART is a well-established procedure that produces binary trees. CHAID, in contrast, admits multiple splittings, a feature that allows to exploit the splitting variable more extensively. On the other hand, that procedure depends on premises that are questionable in practical applications. This can be put down to the fact that CHAID relies on simultaneous Chi-Square- resp. F-tests. The null-distribution of the second test statistic, for instance, relies on the normality assumption that is not plausible in a data mining context. Moreover, none of these procedures - as implemented in SPSS, for instance - take ordinal dependent variables into account. In the paper we suggest an alternative tree-algorithm that: Requires explanatory categorical variables

Dlugosz, Stephan; Müller-Funk, Ulrich

193

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,” 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.

194

Tree of Life  

NSDL National Science Digital Library

This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they explore the Tree of Life cladogram. The site begins with a brief explanation of cladograms and how the Tree of Life shows the relationship of all living things on Earth. A cladogram of fruit is used to demonstrate on a small scale how scientists use this tool to understand how things are similar and different. A portion of the Tree of Life cladogram is included, showing true bacteria, arthropods, mammals, and 11 other important groups of species. Students can mouse over the branching points to see what the subsets have in common. The site also includes a pie chart view that compares the relative size of the most important groups of species. Students can click on each group to learn its characteristics, known species, size range, and other important details.

195

The Probability of Topological Concordance of Gene Trees and Species Trees  

Microsoft Academic Search

The concordance of gene trees and species trees is reconsidered in detail, allowing for samples of arbitrary size to be taken from the species. A sense of concordance for gene tree and species tree topologies is clarified, such that if the “collapsed gene tree” produced by a gene tree has the same topology as the species tree, the gene tree

Noah A. Rosenberg

2002-01-01

196

Trees from the Seas  

NSDL National Science Digital Library

This project provides a case study introducing students to patterns of relationships and evolution among economically important dinoflagellates, the causative agents of red tides. Using nucleotide sequences, students build a tree of relationships among dinoflagellate taxa. They use their tree (along with phylogenetic hypotheses derived from the literature) to explore the evolution of morphological and/or ecological characters in dinoflagellates. As broader applications, students learn to compare and evaluate hypotheses of evolutionary relationships. Additionally, because the case study focuses on dinoflagellates that have evolved toxicity, it can be used to further explore the biological and economic impacts of red tides.

Marsha Timmerman (La Salle University; )

2007-06-17

197

A celestial Christmas tree  

NASA Astrophysics Data System (ADS)

Having finished decorating your terrestrial Christmas tree this year, you may care to step outside and view a celestial one. Well placed in the December night sky in the often overlooked but very rewarding constellation of Monoceros, NGC 2264, called the Christmas Tree by the American astronomer and writer Leland S. Copeland, lies due south around 1 a.m. in mid-December at an altitude of 50°. The cluster lies amid a vast area of nebulosity, well captured in the image by Gordon Rogers on the cover of this Journal.

Moore, S.

2006-12-01

198

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.

John Pratte

199

Tree weight estimates for small-sized trees  

Microsoft Academic Search

This note describes a method for developing accurate equations for determining oven-dried weights of main-stem wood and total (main-stem wood + bark + brench-wood) weight yields of small-sized trees. Separate oven-dried, main-stem wood and total tree weight equations for ages 1-4 for hybrid poplar trees are presented. A comparative summary of selected 4-year-old trees calculated from volume and 3 specific

T. W. Bowersox; W. K. Murphey

1975-01-01

200

TREE LILAC CULTIVARS TESTED AS STREET TREES: INITIAL RESULTS  

Microsoft Academic Search

Three Japanese tree lilac (Syringa reticulata) culti- vars, 2 each in 11 communities, were planted for evaluation as street trees. Cooperators in the Municipal Tree Restora- tion Program using standardized methods measured them annually for 3 years, and periodically afterwards. 'Ivory Silk', 'Regent', and 'Summer Snow' performed well at all locations. All 3 cultivars grew slowly initially, and their foli-

Henry D. Gerhold

1999-01-01

201

Every Tree For Itself A Project Learning Tree Activity  

E-print Network

) Explain that each ring on the tree cookie represents a year of growth. 2) Have the students count the growth rings and report how old the tree was when it was cut down. 3) Give each student a paper plate and crayons and have them draw their own tree cookie. 4) Each student's cookie should have a ring for each

Acton, Scott

202

Hardware-based Reliability Tree (HRT) for fault tree analysis  

Microsoft Academic Search

Reliability analysis of critical systems is performed using fault trees. Fault trees are then converted to their equivalent Binary Decision Diagram, Cut Set, Markov Chain or Bayesian Network. These approaches however are complex and time consuming if a continuous time reliability curve is aimed, particularly for large systems. This paper introduces Hardware-based Reliability Tree (HRT). The HRT can be implemented

Amir Rajabzadeh; Mohammad S. Jahangiry

2010-01-01

203

ENVIRONMENTAL ARBORICULTURE, TREE ECOLOGY AND VETERAN TREE MANAGEMENT  

Microsoft Academic Search

The appreciation and management of veteran trees has been transformed in recent years by the activity of the Ancient Tree Forum (ATF). This is a UK initiative, which has brought attention to the quality and condition of the living heritage reflected in the great number of ancient tree sites found in the British Isles, which are among the finest in

Neville Fay

2002-01-01

204

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.

Stu Cork

2014-01-01

205

4-H SEEDLING TREE PROGRAM  

E-print Network

, erosion control, wind and sound barriers, wild- life habitats, and other conservation purposes. Jefferson2013 4-H SEEDLING TREE PROGRAM Seedling trees for conservation planting in the spring of 2013

206

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

207

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

208

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....

209

A Universal Phylogenetic Tree.  

ERIC Educational Resources Information Center

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

Offner, Susan

2001-01-01

210

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

211

The Sacred Tree.  

ERIC Educational Resources Information Center

Designed as a text for high school students and adults, this illustrated book presents ethical concepts and teachings of Native societies throughout North America concerning the nature and possibilities of human existence. The final component of a course in self-discovery and development, the book begins with the legend of the "Sacred Tree"…

Lethbridge Univ. (Alberta).

212

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

213

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

214

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.

2012-08-03

215

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

216

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...

217

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

218

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.

219

Reconstructing trees from subtree weights  

Microsoft Academic Search

The tree-metric theorem provides a necessary and sufficient condi- tion for a dissimilarity matrix to be a tree metric, and has served as the foundation for numerous distance-based reconstruction methods in phy- logenetics. Our main result is an extension of the tree-metric theorem to more general dissimilarity maps. In particular, we show that a tree with n leaves is reconstructible

Lior Pachter; David E Speyer

2004-01-01

220

Generating trees for permutations avoiding generalized patterns  

E-print Network

Generating trees for permutations avoiding generalized patterns Sergi Elizalde Dartmouth College Permutation Patterns 2006, Reykjavik Permutation Patterns 2006, Reykjavik ­ p.1 #12;Generating trees patterns Generating trees Rightward generating trees Enumeration of permutations avoiding generalized

Elizalde, Sergi

221

Learning Deterministically Recognizable Tree Series  

Microsoft Academic Search

We devise a learning algorithm for deterministically rec- ognizable tree series where the weights are taken from a commutative group. For this, we use an adaptation of the minimal adequate teacher model that was originally introduced by Angluin. The algorithm runs in polynomial time and constructs the unique minimal deterministic bottom-up finite state weighted tree automaton that recognizes the tree

Frank Drewes; Heiko Vogler

2007-01-01

222

Compositions of Tree Series Transformations  

E-print Network

, 19, 4]. So far, the latter are applied in code selection and tree pattern matching [13, 3]. Weighted. The probability is derived from the evidence found in the tree bank. Now the transformation stage translates series; i. e., mappings from a set of trees into a semiring. The translation stage can then be seen

Reyle, Uwe

223

The Hopi Fruit Tree Book.  

ERIC Educational Resources Information Center

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

Nyhuis, Jane

224

Transversals in Trees Victor Campos  

E-print Network

, Belgium, perouz.taslakian@ulb.ac.be 1 #12;Harary and Schwenk [9] call a caterpillar a tree (an unrooted will call a caterpillar any rooted tree where removal of all leaves produces a rooted tree with precisely one leaf. By a full caterpillar of degree d, we will mean a caterpillar where each internal node

Devroye, Luc

225

Qualitative Tree Languages Arnaud Carayol  

E-print Network

Qualitative Tree Languages Arnaud Carayol LIGM (Univ. Paris Est & CNRS) Arnaud) Olivier.Serre@liafa.jussieu.fr Abstract--We study finite automata running over infinite binary trees) of non-accepting branches. In this qualitative setting, a tree is accepted by the automaton

Paris-Sud XI, Université de

226

The Re-Think Tree.  

ERIC Educational Resources Information Center

The Re-Think Tree is a simple framework to help individuals assess and improve their behaviors related to environmental issues. The branches of the tree in order of priority are refuse, reduce, re-use, and recycle. Roots of the tree include such things as public opinion, education, and watchdog groups. (KS)

Gear, Jim

1993-01-01

227

Selecting Trees for Community Landscapes  

Microsoft Academic Search

Selecting the most appropriate trees for various kinds of planting sites is crucial for the success of a municipal tree program. A properly selected tree will appreciate in value for a long time and will be cherished by many people. Conversely, an improper choice might soon become unhealthy or die. Even worse, problems could appear years later when a remedy

Henry D. Gerhold; William Porter

228

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

229

Assignment: Minimum Spanning Trees Name: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

E-print Network

Algorithms Assignment: Minimum Spanning Trees Name 0 11 1 0 00 1 11 0 00 1 11 0011 (a) Find a spanning tree for the Petersen graph with minimum height is at most 2. 2 #12;2. Minimum and maximum spanning trees for the weighted Petersen graph. I J E 4 3 H B C D

Bar-Noy, Amotz

230

The Tree Worker's Manual. [Revised.  

ERIC Educational Resources Information Center

This manual acquaints readers with the general operations of the tree care industry. The manual covers subjects important to a tree worker and serves as a training aid for workers at the entry level as tree care professionals. Each chapter begins with a set of objectives and may include figures, tables, and photographs. Ten chapters are included:…

Lilly, S. J.

231

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

232

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.

233

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.

234

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

235

Random Trees, Heights, and Large Deviations  

Microsoft Academic Search

We present here a general framework to devise a law of large numbers for the height of random trees. Our model unifies the treatment of many examples of the literature such as binary search trees, median-of-(2k + 1) trees, random recursive trees, plane oriented trees, digital search trees, scale-free trees, and all polynomial families of increasing trees, among others. The

Nicolas Broutin

236

Introduction Finite-State Tree Automata  

E-print Network

Introduction Finite-State Tree Automata The Complementation Problem for Automata on Innite Trees;Introduction Finite-State Tree Automata The Complementation Problem for Automata on Innite Trees Outline 1 Introduction Motivation Basic Denitions 2 Finite-State Tree Automata Denitions Muller Tree Automaton Parity

Rabinovich, Alexander

237

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

238

Gene tree correction for reconciliation and species tree inference  

PubMed Central

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

2012-01-01

239

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

240

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

241

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

242

Neuro-fuzzy decision trees.  

PubMed

Fuzzy decision trees are powerful, top-down, hierarchical search methodology to extract human interpretable classification rules. However, they are often criticized to result in poor learning accuracy. In this paper, we propose Neuro-Fuzzy Decision Trees (N-FDTs); a fuzzy decision tree structure with neural like parameter adaptation strategy. In the forward cycle, we construct fuzzy decision trees using any of the standard induction algorithms like fuzzy ID3. In the feedback cycle, parameters of fuzzy decision trees have been adapted using stochastic gradient descent algorithm by traversing back from leaf to root nodes. With this strategy, during the parameter adaptation stage, we keep the hierarchical structure of fuzzy decision trees intact. The proposed approach of applying backpropagation algorithm directly on the structure of fuzzy decision trees improves its learning accuracy without compromising the comprehensibility (interpretability). The proposed methodology has been validated using computational experiments on real-world datasets. PMID:16496439

Bhatt, Rajen B; Gopal, M

2006-02-01

243

Pathogenesis-related protein expression in the apoplast of wheat leaves protected against leaf rust following application of plant extracts.  

PubMed

Leaf rust (Puccinia triticina) is a major disease of wheat. We tested aqueous leaf extracts of Jacaranda mimosifolia (Bignoniaceae), Thevetia peruviana (Apocynaceae), and Calotropis procera (Apocynaceae) for their ability to protect wheat from leaf rust. Extracts from all three species inhibited P. triticina urediniospore germination in vitro. Plants sprayed with extracts before inoculation developed significantly lower levels of disease incidence (number of plants infected) than unsprayed, inoculated controls. Sprays combining 0.6% leaf extracts and 2 mM salicylic acid with the fungicide Amistar Xtra at 0.05% (azoxystrobin at 10 ?g/liter + cyproconazole at 4 ?g/liter) reduced disease incidence significantly more effectively than sprays of fungicide at 0.1% alone. Extracts of J. mimosifolia were most active, either alone (1.2%) or in lower doses (0.6%) in combination with 0.05% Amistar Xtra. Leaf extracts combined with fungicide strongly stimulated defense-related gene expression and the subsequent accumulation of pathogenesis-related (PR) proteins in the apoplast of inoculated wheat leaves. The level of protection afforded was significantly correlated with the ability of extracts to increase PR protein expression. We conclude that pretreatment of wheat leaves with spray formulations containing previously untested plant leaf extracts enhances protection against leaf rust provided by fungicide sprays, offering an alternative disease management strategy. PMID:24624956

Naz, Rabia; Bano, Asghari; Wilson, Neil L; Guest, David; Roberts, Thomas H

2014-09-01

244

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 and species tree problem remains a central problem in phylogenomics. To overcome this problem, gene.1. Gene tree and species tree problem The gene tree/species tree problem is still an important problem

Wong, Limsoon

245

Spanning Trees A spanning tree of a simple graph G is a sub-  

E-print Network

return T Minimum Spanning Trees A minimum spanning tree of a weighted simple graph G is a spanning tree1 Spanning Trees A spanning tree of a simple graph G is a sub- graph that is a tree and contains every vertex. A simple graph is connected if and only if it has a spanning tree. Depth-first search

Bylander, Tom

246

Exact solutions for species tree inference from discordant gene trees.  

PubMed

Phylogenetic analysis has to overcome the grant challenge of inferring accurate species trees from evolutionary histories of gene families (gene trees) that are discordant with the species tree along whose branches they have evolved. Two well studied approaches to cope with this challenge are to solve either biologically informed gene tree parsimony (GTP) problems under gene duplication, gene loss, and deep coalescence, or the classic RF supertree problem that does not rely on any biological model. Despite the potential of these problems to infer credible species trees, they are NP-hard. Therefore, these problems are addressed by heuristics that typically lack any provable accuracy and precision. We describe fast dynamic programming algorithms that solve the GTP problems and the RF supertree problem exactly, and demonstrate that our algorithms can solve instances with data sets consisting of as many as 22 taxa. Extensions of our algorithms can also report the number of all optimal species trees, as well as the trees themselves. To better asses the quality of the resulting species trees that best fit the given gene trees, we also compute the worst case species trees, their numbers, and optimization score for each of the computational problems. Finally, we demonstrate the performance of our exact algorithms using empirical and simulated data sets, and analyze the quality of heuristic solutions for the studied problems by contrasting them with our exact solutions. PMID:24131054

Chang, Wen-Chieh; Górecki, Pawe?; Eulenstein, Oliver

2013-10-01

247

Structural regression trees  

SciTech Connect

In many real-world domains the task of machine learning algorithms is to learn a theory for predicting numerical values. In particular several standard test domains used in Inductive Logic Programming (ILP) are concerned with predicting numerical values from examples and relational and mostly non-determinate background knowledge. However, so far no ILP algorithm except one can predict numbers and cope with nondeterminate background knowledge. (The only exception is a covering algorithm called FORS.) In this paper we present Structural Regression Trees (SRT), a new algorithm which can be applied to the above class of problems. SRT integrates the statistical method of regression trees into ILP. It constructs a tree containing a literal (an atomic formula or its negation) or a conjunction of literals in each node, and assigns a numerical value to each leaf. SRT provides more comprehensible results than purely statistical methods, and can be applied to a class of problems most other ILP systems cannot handle. Experiments in several real-world domains demonstrate that the approach is competitive with existing methods, indicating that the advantages are not at the expense of predictive accuracy.

Kramer, S. [Austrian Research Inst. for Artificial Intelligence, Vienna (Austria)

1996-12-31

248

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

249

A Novel Approach for Compressing Phylogenetic Trees  

NASA Astrophysics Data System (ADS)

Phylogenetic trees are tree structures that depict relationships between organisms. Popular analysis techniques often produce large collections of candidate trees, which are expensive to store. We introduce TreeZip, a novel algorithm to compress phylogenetic trees based on their shared evolutionary relationships. We evaluate TreeZip's performance on fourteen tree collections ranging from 2,505 trees on 328 taxa to 150,000 trees on 525 taxa corresponding to 0.6 MB to 434 MB in storage. Our results show that TreeZip is very effective, typically compressing a tree file to less than 2% of its original size. When coupled with standard compression methods such as 7zip, TreeZip can compress a file to less than 1% of its original size. Our results strongly suggest that TreeZip is very effective at compressing phylogenetic trees, which allows for easier exchange of data with colleagues around the world.

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

250

The fault-tree compiler  

NASA Technical Reports Server (NTRS)

The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

Martensen, Anna L.; Butler, Ricky W.

1987-01-01

251

Tree Level Gauge Mediation  

E-print Network

We propose a new scheme in which supersymmetry breaking is communicated to the MSSM sfermions by GUT gauge interactions at the tree level. The (positive) contribution of MSSM fields to $\\text{Str}(\\mathcal{M}^2)$ is automatically compensated by a (negative) contribution from heavy fields. Sfermion masses are flavour universal, thus solving the supersymmetric flavour problem. In the simplest SO(10) embedding, the ratio of different sfermion masses is predicted and differs from mSugra and other schemes, thus making this framework testable at the LHC. Gaugino masses are generated at the loop level but enhanced by model dependent factors.

Marco Nardecchia; Andrea Romanino; Robert Ziegler

2009-11-27

252

Ice Roads: Steiner Trees  

NSDL National Science Digital Library

In this outdoor activity, learners use pegs (like tent pegs) and string or elastic to simulate drill sites and roads in Northern Canada. Learners are challenged with figuring out how to connect the roads to all the drill sites while keeping the total road length to a minimum. They'll discover that intersections or "Steiner" points provide efficiency between points within a network. Use this activity to introduce learners to computer science themes including Steiner trees, algorithms, and NP-complete problems. Variations, extensions, background information, and solutions are included in the PDF.

Tim Bell

1998-01-01

253

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.

254

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 Noble

255

Human decision error (HUMDEE) trees  

SciTech Connect

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

Ostrom, L.T.

1993-08-01

256

Cellular automata on Cayley tree  

E-print Network

In this paper, we study cellular automata on Cayley tree of order 2 over the field $\\mathbb Z_p$ (the set of prime numbers modulo $p$). We construct the rule matrix corresponding to finite cellular automata on Cayley tree. Further, we analyze the reversibility problem of this cellular automata for some given values of $a,b,c,d\\in \\mathbb{Z}_{p}\\setminus {0}$ and the levels $n$ of Cayley tree. We compute the measure-theoretical entropy of the cellular automata which we define on Cayley tree.

Hasan Akin

2012-11-30

257

Tree Modeling and Dynamics Simulation  

NASA Astrophysics Data System (ADS)

This paper introduces the theory about tree modeling and dynamic movements simulation in computer graphics. By comparing many methods we choose Geometry-based rendering as our method. The tree is decomposed into branches and leaves, under the rotation and quaternion methods we realize the tree animation and avoid the Gimbals Lock in Euler rotation. We take Orge 3D as render engine, which has good graphics programming ability. By the end we realize the tree modeling and dynamic movements simulation, achieve realistic visual quality with little computation cost.

Tian-shuang, Fu; Yi-bing, Li; Dong-xu, Shen

258

Equation Node a_down[ext,tree  

E-print Network

Equation Node exchange7 #12; Unary Binary tree 0 a_down[ext,tree] a_down[inp,tree] a_down_succ[left,out,ext] id_succ[right,inp,ext] id_succ[right,out,ext] r_down[ext,tree] r_down[inp,tree] r_down[out,tree] 1 a_down[ext,tree]=1/2 a_down[inp,tree]=1/2 a_down[out,tree]=1/2 exch_left_succ[inp,ext]=1/2 exch_left_succ[inp,out]=1

Jeannet, Bertrand

259

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 Tree 2, w=71 Tree 3, w=72 Tree 1. w=74 Minimum spanning tree 4 #12; Minimum Spanning Trees A Minimum

Golin, Mordecai J.

260

Lecture 7: Minimum Spanning Trees and Prim's Algorithm  

E-print Network

Lecture 7: 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. The generic Tree 2, w=71 Tree 3, w=72 Tree 1. w=74 Minimum spanning tree 4 #12;Minimum Spanning Trees A Minimum

Wu, Dekai

261

Lecture 7: Minimum Spanning Trees and Prim's Algorithm  

E-print Network

Lecture 7: Minimum Spanning Trees and Prim's Algorithm CLRS Chapter 23 Outline of this Lecture ffl Spanning trees and minimum spanning trees. ffl The minimum spanning tree (MST) problem. ffl The generic graph Tree 2, w=71 Tree 3, w=72 Tree 1. w=74 Minimum spanning tree 4 #12; Minimum Spanning Trees

Wu, Dekai

262

Minimum Spanning Trees Suggested Reading: Chapter 23.  

E-print Network

Minimum Spanning Trees CSE 680 Suggested Reading: Chapter 23. 1 Greedy Method Optimization Problem best at this moment 1 #12;2 Minimum Spanning Trees · Spanning tree: A spanning tree of a connected = (V, E), find a span- ning tree of minimum cost. · Assume V = {1, 2, . . . , n}. 2 #12;3 Prim

Lai, Ten-Hwang "Steve"

263

Minimum Spanning Trees Suggested Reading: Chapter 23.  

E-print Network

Minimum Spanning Trees CSE 2331 Suggested Reading: Chapter 23. 1 Greedy Method Optimization Problem best at this moment 1 #12;2 Minimum Spanning Trees · Spanning tree: A spanning tree of a connected = (V, E), find a span- ning tree of minimum cost. · Assume V = {1, 2, . . . , n}. 2 #12;3 Prim

Lai, Ten-Hwang "Steve"

264

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

265

Operations on Images Using Quad Trees  

Microsoft Academic Search

A quad tree for representing a picture is a tree in which successively deeper levels represent successively finer subdivisions of picture area. An algorithm is given for superposing N quad trees in time proportional to the total number of nodes in the trees. Warnock-type algorithms are then presented for building the quad tree for the picture of the boundary of

Gregory M. Hunter; Kenneth Steiglitz

1979-01-01

266

Critical RWRE on trees and tree-indexed random walks  

Microsoft Academic Search

We study the behavior of Random Walk in Random Environment (RWRE) on trees in the critical case left open in previous work. Representing the random walk by an electrical network, we assume that the ratios of resistances of neighboring edges of a tree Gamma are i.i.d.random variables whose logarithms have mean zero and finite variance. Then the resulting RWRE is

Robin Pemantle; Yuval Peres

2004-01-01

267

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

268

Do Invasive Trees have a Hydraulic Advantage over Native Trees?  

Microsoft Academic Search

The hypothesis was tested that invasive trees have hydraulic traits that contribute to their invasive nature. Five pairs of co-occurring invasive and native trees, in mesic habitats, were selected: (1) Tamarix ramosissima and Salix amygdaloides; (2) Robinia pseudoacacia and Alnus rhombifolia (3) Schinus terebinthifolius and Myrica cerifera; (4) Ligustrum sinense and Acer negundo; and (5) Sapium sebiferum and Diospyros virginiana,

R B Pratt; R A Black

2006-01-01

269

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

E-print Network

intraspecific competition among even-aged woody plants (Kenkel 1988, Baldwin et al. 2000) and woody saplings (Shainsky and Radosevich 1992) has been demonstrated, evidence for the importance of such interactions in natural woodlands (Duncan 1991...). Evidence of competition between savanna trees has been largely inferential (Penridge and Walker 1986, Kenkel 1988, Martens et al. 1997, Scholes and Archer 1997), but has indicated that competition intensity increases with increasing tree density. Tree...

Simmons, Mark Trevor

2004-11-15

270

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

271

Distributed Merge Trees  

SciTech Connect

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

Morozov, Dmitriy; Weber, Gunther

2013-01-08

272

Discordance of Species Trees with Their Most Likely Gene Trees: The Case of Five Taxa  

Microsoft Academic Search

Under a coalescent model for within-species evolution, gene trees may differ from species trees to such an extent that the gene tree topology most likely to evolve along the branches of a species tree can disagree with the species tree topology. Gene tree topologies that are more likely to be produced than the topology that matches that of the species

NOAH A. ROSENBERG; RANDA TAO

2008-01-01

273

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

274

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

275

Fuzzy SLIQ decision tree algorithm.  

PubMed

Traditional decision tree algorithms face the problem of having sharp decision boundaries which are hardly found in any real-life classification problems. A fuzzy supervised learning in Quest (SLIQ) decision tree (FS-DT) algorithm is proposed in this paper. It is aimed at constructing a fuzzy decision boundary instead of a crisp decision boundary. Size of the decision tree constructed is another very important parameter in decision tree algorithms. Large and deeper decision tree results in incomprehensible induction rules. The proposed FS-DT algorithm modifies the SLIQ decision tree algorithm to construct a fuzzy binary decision tree of significantly reduced size. The performance of the FS-DT algorithm is compared with SLIQ using several real-life datasets taken from the UCI Machine Learning Repository. The FS-DT algorithm outperforms its crisp counterpart in terms of classification accuracy. FS-DT also results in more than 70% reduction in size of the decision tree compared to SLIQ. PMID:18784012

Chandra, B; Varghese, P Paul

2008-10-01

276

Genetic conservation of native trees  

E-print Network

Genetic conservation of native trees Scott McG. Wilson1 and C. J. A. Samuel Over recent years, the genetic conservation of British native tree populations has become an increasingly important part policy-makers in the genetic basis of forest biodiversity conservation, both at the UK and, more

277

Hazard Tree Management for Camps.  

ERIC Educational Resources Information Center

The principles behind a camp's hazard tree program are, first, identifying and removing those hazards that offer a clear, immediate threat, and then creating a management plan for the other trees. The plan should be written and contain goals and objectives, field evaluations, and treatments. Follow-up evaluations should be done annually and after…

Kong, Earl

2002-01-01

278

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

279

4-H SEEDLING TREE PROGRAM  

E-print Network

for refor- estation, erosion control, wind and sound barriers, wild- life habitats, and other conservation2014 4-H SEEDLING TREE PROGRAM Seedling trees for conservation planting in the spring of 2014 Forest Service, are available to anyone, but must be used for conservation purposes. They may be planted

Stephens, Graeme L.

280

Computing minimum spanning trees efficiently  

Microsoft Academic Search

A ubiquitous problem in mathematical programming is the calculation of minimum spanning trees. Minimum spanning tree algorithms find application in such diverse areas as: least cost electrical wiring, minimum cost connecting communication and transportation networks, network reliability problems, minimum stress networks, clustering and numerical taxonomy, algorithms for solving traveling salesman problems, and multiterminal network flows. It is therefore important to

A. Kershenbaum; R. Van Slyke

1972-01-01

281

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).

E. Strauss

282

Carbon14 in tree rings  

Microsoft Academic Search

In order to investigate how reliably the carbon 14 content of tree rings reflects that of atmospheric carbon dioxide, two types of determinations were carried out: (1) carbon 14 determinations in annual rings from the beginning of this century until 1974 and (2) carbon 14 determinations in synchronous wood from the North American bristlecone pine and from European oak trees,

William F. Cain; Hans E. Suess

1976-01-01

283

Mixtures of (Constrained) Ultrametric Trees.  

ERIC Educational Resources Information Center

Presents a method for the estimation of ultrametric trees calibrated on subjects' pairwise proximity judgments of stimuli, capturing subject heterogeneity using a finite mixture formulation. An empirical example from published data shows the ability to deal with external constraints on the tree topology. (Author/SLD)

Wedel, Michel; DeSarbo, Wayne S.

1998-01-01

284

Ancient stunted trees on cliffs  

Microsoft Academic Search

An undisturbed ancient woodland, dominated by tiny, slow-growing and widely spaced trees, grows on vertical cliffs of the Niagara escarpment in southern Canada. To investigate whether this woodland is unusual or is part of a previously undetected global pattern, we sampled ages and radial growth rates for trees on cliffs in the United States and in western Europe. We find

D. W. Larson; U. Matthes; J. A. Gerrath; J. M. Gerrath; J. C. Nekola; G. L. Walker; S. Porembski; A. Charlton; N. W. K. Larson

1999-01-01

285

Tree Hydraulics: How Sap Rises  

ERIC Educational Resources Information Center

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

Denny, Mark

2012-01-01

286

On Cartesian trees and range minimum queries  

E-print Network

We present new results on Cartesian trees with applications in range minimum queries and bottleneck edge queries. We introduce a cache-oblivious Cartesian tree for solving the range minimum query problem, a Cartesian tree ...

Demaine, Erik D.

287

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

288

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

289

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

290

75 FR 25103 - Tree Assistance Program  

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-05-07

291

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

292

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

293

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

294

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

295

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

296

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

297

Terrestrial apes and phylogenetic trees  

PubMed Central

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

Arsuaga, Juan Luis

2010-01-01

298

How Monkeys Use Energy to Leap from Tree to Tree  

NSDL National Science Digital Library

The representation is a diagram with accompanying text, showing conversions as energy goes from the sun (electromagnetic) to the tree (chemical) to the monkey; describes how the monkey converts chemical energy into motion and heat.

David E Watson

299

Tree Search and Quantum Computation  

E-print Network

Traditional tree search algorithms supply a blueprint for modeling problem solving behaviour. A diverse spectrum of problems can be formulated in terms of tree search. Quantum computation, in particular Grover's algorithm, has aroused a great deal of interest since it allows for a quadratic speedup to be obtained in search procedures. In this work we consider the impact of incorporating classical search concepts alongside Grover's algorithm into a hybrid quantum search system. Some of the crucial points examined include: (1) the reverberations of contemplating the use of non-constant branching factors; (2) determining the consequences of incorporating an heuristic perspective into a quantum tree search model.

Luís Tarrataca; Andreas Wichert

2015-02-06

300

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

301

S-Tree: a technique for buffered routing tree synthesis  

Microsoft Academic Search

We present the S-Tree algorithm for synthesis of buffered interconnects. The approach incorporates a unique combination of real-world issues (handling of routing and buffer blockages, cost minimization, critical sink isolation, sink polarities), robustness and scalability. The algorithm is able to achieve the slack comparable to that of buffered P-Tree [7] using less resources (wire and buffers) in an order of

Miloš Hrki?; John Lillis

2002-01-01

302

On some relations between 2-trees and tree metrics  

Microsoft Academic Search

A tree function (TF) t on a finite set X is a real function on the set of the pairs of elements of X satisfying the four-point condition: for all distinctx, y, z, w ? X, t(xy)+t(zw)? max{t(xz) + t(yw), t(xw) + t(yz)}. Equivalently, t is representable by the lengths of the paths between the leaves of a valued tree

Bruno Leclerc; Vladimir Makarenkov

1998-01-01

303

Vascularization with trees that alternate with upside-down trees  

NASA Astrophysics Data System (ADS)

This article describes the generation of dendritic flow architectures that provide maximum side-to-side flow access, across a vascularized body. The flow architecture consists of trees that alternate with upside-down trees (a ,b,a,b,…). If in tree "a" the flow is from root to canopy, in tree "b" the flow is from canopy to root. This means that the flow proceeds in the same direction through all the trees, i.e., the flow is oriented side-to-side, or line-to-line. The channel cross sections are rectangular, and they all have the same depth. The article shows under what conditions the tree vascularization offers greater flow access than parallel single-scale channels oriented perpendicularly to the two parallel lines. The analytical part of the work is based on the assumption of fully developed laminar flow in every channel. The numerical part consists of simulations of three-dimensional laminar flow through the entire tree architecture and its many bifurcations. It is shown that tree vascularization is more attractive than parallel channels when the number of bifurcation levels increases, the global porosity of the vascularized body decreases, and the global svelteness (Sv) of the flow architecture increases. The nonuniformity (maldistribution) of flow rates through ramifications of the same rank becomes nonnegligible when the pressure drop number (Be) exceeds 109. The optimal step in the sizes of cross-sectional areas from one channel to the channel of the next rank is closely approximated by 22/3 even when the cross section is not square or round. The agreement between analysis and numerical simulation and optimization is good.

Zhang, Houlei; Lorente, Sylvie; Bejan, Adrian

2007-05-01

304

AVL Tree Applet  

NSDL National Science Digital Library

On its first applet interface, this visualization shows randomly generated input and then allows user to add user defined input. In addition, it has tree size control options; sound options that work seamlessly with all the animations; the animation speed control options. Textual description of each operation as well as pre and post-order traversals are provided in the visualization. Other fancy options like shape control feature and direction control features are also included. Moreover, images on command buttons help users use this tool intuitively. The visualization also shows the basic splay operation for comparison to AVL. This visualization provides several options like user defined data, step-wise speed control, description of each operation with valuable visual effects so that a user can fit the tool to his/her preference. It also provides sound effects and animation effect, in particular, rotation signs before executing operations. This application is highly intuitive with simple and smooth animation. The descriptions after the operation has completed give an insight into what operations the Algorithm visualization went through. The write up provided by author for the algorithm in general is also insightful. Interface provides options to insert node, delete node and find nodes in predetermined or user defined dataset. It also provides good control over the speed of animation. Despite its neat design, the visualization is missing some options. The next button is missing (hence no step by step trace capability) which could have been an added advantage. The layout is pretty decent but it cannot support a large set of numbers. It shows the basic splay operation which was missing in earlier visualizations. But sadly, one cannot control the pacing of the splay operation and it splays the node selected to the root through a series of fast visual iterations. One needs to control the pace of these iterations to have better understanding of the AVL concept which forms the basis of AVL. Further, once we press 'AVL' button, there is no getting back. One has to have a basic knowledge of the BSTs and Self Balancing trees to work with this visualization and this cannot be given to novices who have not taken any Data Structures course till now. Though a beef-up of the basic operations by providing pace control, 'Previous' and 'Next' Buttons, and a short text box that explains what happened in a particular iteration would make this AV a very potent and useful tool for all user groups. Recommended as lecture aide, standalone, self-study suppliment to tutorial or lecture.

Arsen Gogeshvili

305

Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative  

NASA Astrophysics Data System (ADS)

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

Pincetl, Stephanie

2010-02-01

306

Implementing municipal tree planting: Los Angeles million-tree initiative.  

PubMed

Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic-living-infrastructure has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been written on the process of implementing urban tree planting programs. The investigative methods were primarily qualitative, involving interviews, attending meetings and conducting literature reviews. Results indicate that multiple nonprofit and city agency programs are involved in planting and maintaining trees and this has required coordination among groups that here-to-fore were unaccustomed to having to collaborate. The main finding that emerge from this research is that the implementation of such a program in Los Angeles is more complicated than it may seem due to several interacting factors: the need to rely on multiple public and private organizations to put trees into the ground and to maintain them; coordination of these multiple efforts must be centralized, but requires a great deal of time and effort and maybe resisted by some of the partners; funding for planting and long term maintenance must be pieced together from multiple sources; acceptance of trees by residents varies by neighborhood as does tree canopy cover; appropriate nursery supply can be limited; the location of the program within the city administration is determined by who initiates the program. PMID:20016982

Pincetl, Stephanie

2010-02-01

307

Performance Evaluation of Main-Memory R-tree Variants  

Microsoft Academic Search

There have been several techniques proposed for improving the per- formance of main-memory spatial indexes, but there has not been a comparative study of their performance. In this paper we compare the performance of six main-memory R-tree variants: R-tree, R*-tree, Hilbert R-tree, CR-tree, CR*- tree, and Hilbert CR-tree. CR*-trees and Hilbert CR-trees are respectively a natural extension of R*-trees and

Sangyong Hwang; Keunjoo Kwon; Sang Kyun Cha; Byung Suk Lee

2003-01-01

308

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

309

Trees, networks, and hydrology  

NASA Astrophysics Data System (ADS)

This paper reviews theoretical and observational material on form and function of natural networks appeared in somewhat disparate contexts from physics to biology, whose study is related to hydrologic research. Moving from the exact result that drainage network configurations minimizing total energy dissipation are stationary solutions of the general equation describing landscape evolution, we discuss the properties and the dynamic origin of the scale-invariant structure of river patterns and its relation to optimal selection. We argue that at least in the fluvial landscape, nature works through imperfect searches for dynamically accessible optimal configurations and that purely random or deterministic constructs are clearly unsuitable to properly describe natural network forms. We also show that optimal networks are spanning loopless configurations only under precise physical requirements that arise under the constraints imposed by continuity. In the case of rivers, every spanning tree proves a local minimum of total energy dissipation. This is stated in a theorem form applicable to generic networks, suggesting that other branching structures occurring in nature (e.g., scale-free and looping) may possibly arise through optimality to different selective pressures. We thus conclude that one recurrent self-organized mechanism for the dynamic origin of fractal forms is the robust strive for imperfect optimality that we see embedded in many natural patterns, chief and foremost hydrologic ones.

Rinaldo, Andrea; Banavar, Jayanth R.; Maritan, Amos

2006-06-01

310

Trees, networks and optimality  

NASA Astrophysics Data System (ADS)

Theoretical and observational material on form and function of natural networks appeared in somewhat disparate contexts from physics to biology is critically reviewed. Moving from the exact result that drainage network configurations minimizing total energy dissipation are stationary solutions of the general equation describing landscape evolution, the properties and the dynamic origin of the scale-invariant structure of river patterns are discussed in relation to optimal selection. It is argued that at least in the fluvial landscape Nature works through imperfect searches for dynamically accessible optimal configurations and that purely random or deterministic constructs are clearly unsuitable to properly describe natural network forms. We also show that optimal networks are spanning loopless configurations only under precise physical requirements that arise under the constraints imposed by continuity. In the case of rivers, every spanning tree proves a local minimum of total energy dissipation. This is stated in a theorem form applicable to generic networks, suggesting that other branching structures occurring in nature (e.g., scale-free and looping) may possibly arise through optimality to different selective pressures. It is thus suggested that one recurrent self- organized mechanism for the dynamic origin of fractal forms is the robust strive for imperfect optimality that it is observed in many natural patterns, chief and foremost hydrologic ones.

Rinaldo, A.

2008-12-01

311

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 constructing that best explains the data, generally by "walking" from tree to tree. Whatever optimality criterion is used from each other, the consensus tree of the whole set will contain very few internal nodes, all of high

Amenta, Nina

312

Progress in the biotechnology of trees  

Microsoft Academic Search

An increasing world population and rise in demand for tree products, especially wood, has increased the need to produce more timber through planting more forest with improved quality stock. Superior trees are likely to arise from several sources. Firstly, forest trees can be selected from wild populations and cloned using macropropagation techniques already being investigated for fruit tree rootstocks. Alternatively,

N. Hammatt

1992-01-01

313

Tree Induction for Probability-Based Ranking  

Microsoft Academic Search

Tree induction is one of the most effective and widely used methods for building classification models. However, many applications require cases to be ranked by the probability of class membership. Probability estimation trees (PETs) have the same attractive features as classification trees (e.g., comprehensibility, accuracy and efficiency in high dimensions and on large data sets). Unfortunately, decision trees have been

Foster J. Provost; Pedro Domingos

2003-01-01

314

TREE MAINTENANCE AND REMOVAL 31. A GENERAL  

E-print Network

EM 385-1-1 XX Jun 13 SECTION 31 TREE MAINTENANCE AND REMOVAL 31. A GENERAL 31.A.01 References. a, and Distribution; d. ANSI A300 ­ American National Standard for Tree Care Operations ­ Tree, Shrub, and Other Woody- Mounted Elevating and Rotating Aerial Devices. 31.A.02 Tree maintenance or removal shall be performed

US Army Corps of Engineers

315

The Alternating Decision Tree Learning Algorithm  

Microsoft Academic Search

The application of boosting procedures to decisiontree algorithms has been shown to producevery accurate classifiers. These classifiersare in the form of a majority vote overa number of decision trees. Unfortunately,these classifiers are often large, complex anddifficult to interpret. This paper describes anew type of classification rule, the alternatingdecision tree, which is a generalization ofdecision trees, voted decision trees and voteddecision

Yoav Freund; Llew Mason

1999-01-01

316

The Constrained Minimum Spanning Tree (Extended Abstract)  

E-print Network

The Constrained Minimum Spanning Tree Problem (Extended Abstract) R. Ravi* M. X. Goemanst Abstract algorithm, minimum spanning trees, La- grangean relaxation, adjacency relations. 1 Introduction Given. In this case, we can specify a budget L on the total length of the spanning tree and require a tree of minimum

Goemans, Michel X.

317

On the Euclidean Minimum Spanning Tree Problem  

E-print Network

On the Euclidean Minimum Spanning Tree Problem Sanguthevar Rajasekaran Dept. of CSE, University of Connecticut Storrs, CT 06269 Abstract Given a weighted graph G(V, E), a minimum spanning tree for G can a minimum spanning tree for this graph is known as the Euclidean minimum spanning tree problem (EMSTP

Rajasekaran, Sanguthevar

318

"Dangerous" urban trees & community health & safety  

E-print Network

"Dangerous" urban trees & community health & safety Norman Dandy Forest Research #12;Urban trees, safety & climate change · Forest Research project "Climate change and street trees" · Reviews the governance structures relating to [individual] trees in the urban environment · Strong governance protecting

319

Practice Guide Raising trees and shrubs  

E-print Network

Practice Guide Raising trees and shrubs from seed #12;Raising trees and shrubs from seed Peter). Raising trees and shrubs from seed. Forestry Commission Practice Guide. Forestry Commission, Edinburgh. i­iv + 1­28 pp. Keywords: collection; dormancy; germination; pretreatment; processing; storage; tree seeds

320

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

321

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

322

Research Summary Health Benefits of Street Trees  

E-print Network

Research Summary Health Benefits of Street Trees Street trees can have an important role. Health and well-being objectives have been elements of each country's forest strategy, and street trees This research aimed to: o Assess recent economic evidence of the health benefits provided by street trees

323

Growing a Forest for the Trees.  

ERIC Educational Resources Information Center

Describes a tree studies program in a fourth-grade classroom. Students collected local tree seeds and seeds from supermarket fruits, researched growing conditions, and grew seeds under various conditions. Students kept journals on local trees, observing seed dispersal mechanisms and examining rings on trunk slices. Inquiry-based tree studies…

Growing Ideas, 2001

2001-01-01

324

Tree Growth Rings: What They Tell Us.  

ERIC Educational Resources Information Center

Activities in which students can learn to determine the history of a tree from the growth pattern recorded in the rings of a cross-section of a tree are described. Activities include background information, objectives, a list of needed materials per group, and procedures. Cross-sections of four different tree types are included if real tree

Sunal, Dennis W.; Sunal, Cynthia Szymanski

1991-01-01

325

MANAGEMENT INFORMATION SYSTEMS FOR URBAN TREES1  

Microsoft Academic Search

The concept and applications of computerized in- formation systems for the management of urban trees are reviewed. Among their uses are landscape planning, choosing species to be planted, organizing work on trees, departmental planning and evaluation, and public relations. Five types of data required for these purposes pertain to the location of trees, tree characteristics, site characteristics, actions recom- mended,

Henry D. Gerhold; Kim C. Steiner; C. J. Sacksteder

1987-01-01

326

Inferring species trees from gene duplication episodes  

Microsoft Academic Search

Gene tree parsimony, which infers a species tree that implies the fewest gene duplications across a collection of gene trees, is a method for inferring phylogenetic trees from paralogous genes. However, it assumes that all duplications are independent, and therefore, it does not account for large-scale gene duplication events like whole genome duplications. We describe two methods to infer species

J. Gordon Burleigh; Mukul S. Bansal; Oliver Eulenstein; Todd J. Vision

2010-01-01

327

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

328

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

329

Core Based Trees (CBT) Multicast Routing Architecture  

Microsoft Academic Search

CBT is a multicast routing architecture that builds a single delivery tree per group which is shared by all of the group's senders and receivers. Most multicast algorithms build one multicast tree per sender (subnetwork), the tree being rooted at the sender's subnetwork. The primary advantage of the shared tree approach is that it typically offers more favourable scaling characteristics

A. Ballardie

1997-01-01

330

Tunnel of the California Tunnel Tree  

USGS Multimedia Gallery

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

331

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

332

Tree Rings as Temperature Proxies  

Microsoft Academic Search

Tree-ring series provide the most widely distributed and easily accessible archive of annually resolved proxy climate data. In regions with well-defined seasonal growth the annual growth rings of trees provide both chronological control and a continuous time series of proxy environmental variables. The year to year variability of the physical (e.g. width, density) and chemical properties of these annual rings

Brian H. Luckman

2008-01-01

333

Limit theorems for random trees.  

PubMed Central

This paper is concerned with random rooted trees and studies the distribution of the vertices according to their altitude. If the trees are chosen at random with an increasing number of vertices, then, by a suitable normalization, the distribution function of the number of vertices at a given altitude and the distribution function of the total height approach specific limits. Explicit formulas are given for these limit distribution functions and their moments. PMID:11607295

Takàcs, L

1992-01-01

334

Fault Tree Analysis: A Bibliography  

NASA Technical Reports Server (NTRS)

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

2000-01-01

335

On distances between phylogenetic trees  

Microsoft Academic Search

Different phylogenetic trees for the same group of species are often produced either by proceduresthat use diverse optimality criteria [18] or from different genes [12] in the study of molecularevolution. Comparing these trees to find their similarities (e.g. agreement or consensus) anddissimilarities, i.e. distance, is thus an important issue in computational molecular biology.The nearest neighbor interchange (nni) distance [26, 24,

B. DasGupta; X. He; T. Jiang; M. Li; J. T. Tromp; L. Zhang

1997-01-01

336

Phenological Variation of Forest Trees  

Microsoft Academic Search

\\u000a Observations of Beech trees in Switzerland show relevant differences in the phenology of the single individual. Within the\\u000a collective of Beech trees, the state of phenological development differs from about one to nineteen days for leaf unfolding,\\u000a and about six to thirty-six days for leaf coloring. Data on the occurrence of specific phenophases and their absolute differences\\u000a within a collective

Robert Brügger; Matthias Dobbertin; Norbert Kräuchi

337

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.

338

REPLACEMENT OF TREES UNDER UTILITY WIRES IMPACTS ATTITUDES AND COMMUNITY TREE PROGRAMS  

Microsoft Academic Search

Opinions of people in 54 Pennsylvania munici- palities who received trees through the Municipal Tree Restoration Program (MTRP) were surveyed, and progress in their tree programs also was evaluated. All municipal tree program components, such as ordinances, tree com- missions, inventories, and management plans, were stimulated by the MTRP to varying extents in one or more ways in 91% of

Dana E. Flowers; Henry D. Gerhold

2000-01-01

339

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

340

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

341

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

342

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

343

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

344

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

345

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

346

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

347

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

348

Multipolar consensus for phylogenetic trees.  

PubMed

Collections of phylogenetic trees are usually summarized using consensus methods. These methods build a single tree, supposed to be representative of the collection. However, in the case of heterogeneous collections of trees, the resulting consensus may be poorly resolved (strict consensus, majority-rule consensus, ...), or may perform arbitrary choices among mutually incompatible clades, or splits (greedy consensus). Here, we propose an alternative method, which we call the multipolar consensus (MPC). Its aim is to display all the splits having a support above a predefined threshold, in a minimum number of consensus trees, or poles. We show that the problem is equivalent to a graph-coloring problem, and propose an implementation of the method. Finally, we apply the MPC to real data sets. Our results indicate that, typically, all the splits down to a weight of 10% can be displayed in no more than 4 trees. In addition, in some cases, biologically relevant secondary signals, which would not have been present in any of the classical consensus trees, are indeed captured by our method, indicating that the MPC provides a convenient exploratory method for phylogenetic analysis. The method was implemented in a package freely available at http://www.lirmm.fr/~cbonnard/MPC.html PMID:17060203

Bonnard, Cécile; Berry, Vincent; Lartillot, Nicolas

2006-10-01

349

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

350

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

351

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

352

Methane Emissions from Upland Trees  

NASA Astrophysics Data System (ADS)

Most work on methane (CH4) emissions from natural ecosystems has focused on wetlands and wetland soils because they are predictable emitters and relatively simple to quantify. Less attention has been directed toward upland ecosystems that cover far larger areas, but are assumed to be too dry to emit CH4. There is abundant evidence that upland ecosystems emit small amounts of CH4 during hot moments that collectively constitute a significant source in the global budget of this potent greenhouse gas. We have established two transects across natural moisture gradients in two forests near Annapolis, Maryland. Both tree and soil methane fluxes were measured using chamber methods. Each tree chamber was custom fit to the stem near the base. In addition, porewater methane concentrations were collected at multiple depths near trees. Abiotic parameters such as soil temperature, soil moisture, water potential, and depth to groundwater were monitored using a wireless sensor network. Upland emissions from tree stems were as high as 14.6 umoles CH4 m-2 hr-1 while the soil uptake was -1.5 umoles CH4 m-2 hr-1. These results demonstrate that tree methane emissions and soil methane uptake can occur simultaneously in a mesic forest. Factors controlling methane emissions were soil temperature, soil moisture, and depth to groundwater. Based on our preliminary data, tree mediated methane emissions may be offsetting the soil methane sink of upland forests by 20 to 30%. Future methane budgets and climate models will need to include tree fluxes and the parameters that control methane emissions for accurate accounting and predictions.

Pitz, S.; Megonigal, P.; Schile, L. M.; Szlavecz, K. A.; King, K.

2013-12-01

353

A characterization of the set of species trees that produce anomalous ranked gene trees.  

PubMed

Ranked gene trees, which consider both the gene tree topology and the sequence in which gene lineages separate, can potentially provide a new source of information for use in modeling genealogies and performing inference of species trees. Recently,we have calculated the probability distribution of ranked gene trees under the standard multispecies coalescent model for the evolution of gene lineages along the branches of a fixed species tree, demonstrating the existence of anomalous ranked gene trees (ARGTs), in which a ranked gene tree that does not match the ranked species tree can have greater probability under the model than the matching ranked gene tree. Here, we fully characterize the set of unranked species tree topologies that give rise to ARGTs, showing that this set contains all species tree topologies with five or more taxa, with the exceptions of caterpillars and pseudocaterpillars. The results have implications for the use of ranked gene trees in phylogenetic inference. PMID:22868677

Degnan, James H; Rosenberg, Noah A; Stadler, Tanja

2012-01-01

354

arXiv:cs.DS/0205045 Balancing Minimum Spanning Trees  

E-print Network

arXiv:cs.DS/0205045 v1 18 May 2002 Balancing Minimum Spanning Trees and Shortest-Path Trees Samir-path tree and a minimum spanning tree. The algorithm provides a continuous trade-o#11;: given the two trees of the tree is at most 1 + p 2= times the weight of a minimum spanning tree. Our algorithm runs in linear

Raghavachari, Balaji

355

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. w=74 Minimum spanning tree 4 #12;Minimum Spanning Trees A Minimum Spanning Tree in an undirected

Golin, Mordecai J.

356

Splay trees: a reweighing lemma and a proof of competitiveness vs. dynamic balanced trees  

Microsoft Academic Search

We give a new lemma (dynamic reweighing) about splay trees and we define a class of dynamically self-adjusted trees (parametrically balanced) wide enough to include BB(?), AVL, rank-balanced and B-trees. Using our lemma we prove that splay trees are competitive to any such class of dynamic trees—noticing that so far splay trees had been proven competitive only w.r.t. static structures

George F. Georgakopoulos

2004-01-01

357

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

358

Recognition of a Spanning Tree of Directed Acyclic Graphs by Tree Automata  

Microsoft Academic Search

In this paper, we study tree automata for directed acyclic graphs (DAGs). We define the movement of a tree automaton on a\\u000a DAG so that a DAG is accepted by a tree automaton if and only if a DAG has a spanning tree accepted by a tree automaton. The\\u000a NP-completeness of the membership problem of DAGs for a tree automaton

Akio Fujiyoshi

2009-01-01

359

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

360

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

361

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

362

Properties of consensus methods for inferring species trees from gene trees.  

PubMed

Consensus methods provide a useful strategy for summarizing information from a collection of gene trees. An important application of consensus methods is to combine gene trees to estimate a species tree. To investigate the theoretical properties of consensus trees that would be obtained from large numbers of loci evolving according to a basic evolutionary model, we construct consensus trees from rooted gene trees that occur in proportion to gene-tree probabilities derived from coalescent theory. We consider majority-rule, rooted triple (R(*)), and greedy consensus trees obtained from known, rooted gene trees, both in the asymptotic case as numbers of gene trees approach infinity and for finite numbers of genes. Our results show that for some combinations of species-tree branch lengths, increasing the number of independent loci can make the rooted majority-rule consensus tree more likely to be at least partially unresolved. However, the probability that the R(*) consensus tree has the species-tree topology approaches 1 as the number of gene trees approaches infinity. Although the greedy consensus algorithm can be the quickest to converge on the correct species-tree topology when increasing the number of gene trees, it can also be positively misleading. The majority-rule consensus tree is not a misleading estimator of the species-tree topology, and the R(*) consensus tree is a statistically consistent estimator of the species-tree topology. Our results therefore suggest a method for using multiple loci to infer the species-tree topology, even when it is discordant with the most likely gene tree. PMID:20525567

Degnan, James H; DeGiorgio, Michael; Bryant, David; Rosenberg, Noah A

2009-02-01

363

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

364

Cache Oblivious Search Trees via Binary Trees of Small Height  

E-print Network

for laying out a search tree in memory. 1 Introduction Modern computers contain a hierarchy of memory levels, with each level acting as a cache for the next. Typical components of the memory hierarchy are: registers widely used of these is the I/O model of Aggarwal and Vitter [1], which assumes a memory hierarchy

Riko Jacob

365

CONTEXT-TREE WEIGHTING FOR EXTENDED TREE SOURCES  

Microsoft Academic Search

At the ISIT'95 Suzuki (1) presented a context weighting algorithm that covered a more general class of sources than the context-tree weighting method, at the cost of some extra complexity. Here his algorithm will be compared to an algorithm, that covers the same model class. Most modern universal source coding algorithms are based on statistical tech- niques. These algorithms consist

Paul A. J. Volf; Frans M. J. Willems

366

Water Transport in Trees--An Artificial Laboratory Tree  

ERIC Educational Resources Information Center

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

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

2011-01-01

367

Estimating optimal species trees from incomplete gene trees under deep coalescence.  

PubMed

The estimation of species trees typically involves the estimation of trees and alignments on many different genes, so that the species tree can be based on many different parts of the genome. This kind of phylogenomic approach to species tree estimation has the potential to produce more accurate species tree estimates, especially when gene trees can differ from the species tree due to processes such as incomplete lineage sorting (ILS), gene duplication and loss, and horizontal gene transfer. Because ILS (also called "deep coalescence") is a frequent problem in systematics, many methods have been developed to estimate species trees from gene trees or alignments that specifically take ILS into consideration. In this paper we consider the problem of estimating species trees from gene trees and alignments for the general case where the gene trees and alignments can be incomplete, which means that not all the genes contain sequences for all the species. We formalize optimization problems for this context and prove theoretical results for these problems. We also present the results of a simulation study evaluating existing methods for estimating species trees from incomplete gene trees. Our simulation study shows that *BEAST, a statistical method for estimating species trees from gene sequence alignments, produces by far the most accurate species trees. However, *BEAST can only be run on small datasets. The second most accurate method, MRP (a standard supertree method), can analyze very large datasets and produces very good trees, making MRP a potentially acceptable alternative to *BEAST for large datasets. PMID:22697236

Bayzid, Md Shamsuzzoha; Warnow, Tandy

2012-06-01

368

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

369

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

370

SELECTING AND TESTING STREET TREE CULTIVARS  

Microsoft Academic Search

ABSTRAC T- - To improve street trees through better selection of species 1 and cultivars is an important goal of the Municipal Tree Restoration Program . Communities have been assisted by publishing \\

HENRY D. GERHOLD

371

Secondhand Trees, Firsthand Learning. Holiday Evergreens Revitalized.  

ERIC Educational Resources Information Center

Described is an activity that uses discarded evergreen trees from Christmas. Tree age and growth characteristics are investigated by looking at the number of whorls and rings of the trunks. Extensions and follow-up activities are included. (KR)

Graves, C. John

1990-01-01

372

Generating Functions for Multi-labeled Trees  

PubMed Central

Multi-labeled trees are a generalization of phylogenetic trees that are used, for example, in the study of gene versus species evolution and as the basis for phylogenetic network construction. Unlike phylogenetic trees, in a leaf-multi-labeled tree it is possible to label more than one leaf by the same element of the underlying label set. In this paper we derive formulae for generating functions of leaf-multi-labeled trees and use these to derive recursions for counting such trees. In particular, we prove results which generalize previous theorems by Harding on so-called tree-shapes, and by Otter on relating the number of rooted and unrooted phylogenetic trees. PMID:23175592

Erd?s, P.L.; Johnson, V.; Moulton, V.

2012-01-01

373

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

374

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

375

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

376

Dependency Tree Automata Colin Stirling  

E-print Network

.r.t. finite value sets) [Ghica + McCusker 2000, Ong 2002, . . .] #12;Active research goal: transfer of idealized Algol (w.r.t. finite value sets) [Ghica + McCusker 2000, Ong 2002, . . .] 2. Model checking higher-order trees [Knapik + Niwinski + Urzyczyn 2002, Caucal 2002, Ong 2006, Hague + Murawski + Ong +Serre, 2008

Stirling, Colin

377

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

378

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

379

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

380

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

381

Remembering Without Memory: Tree Exploration  

E-print Network

. In the effort to understand the algorithmic limitations of computing by a swarm of robots, the research has.1007/978-3-540-69355-0_5 #12;problem to be solved by a swarm of robots. In the investigations, three models are commonly usedRemembering Without Memory: Tree Exploration by Asynchronous Oblivious Robots Paola Flocchini1

Paris-Sud XI, Université de

382

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

383

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.

Karen Johnson

384

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...

385

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

386

Dynamical Systems Trees Tony Jebara  

E-print Network

extended traditional dynamical systems, improving upon classical linear Kalman filters and hidden Markov dynamical systems (SLDSs) that combine Kalman filters and HMMs [9, 1, 7, 5] to obtain nonlinear continuous interact as communities and sub-communities in a tree structure that is un- rolled in time. To accommodate

Jebara, Tony

387

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...

388

Stable isotopes in tree rings  

Microsoft Academic Search

Stable isotopes in tree rings could provide palaeoclimate reconstructions with perfect annual resolution and statistically defined confidence limits. Recent advances make the approach viable for non-specialist laboratories. The relevant literature is, however, spread across several disciplines, with common problems approached in different ways. Here we provide the first overview of isotope dendroclimatology, explaining the underlying theory and describing the steps

Danny McCarroll; Neil J. Loader

2004-01-01

389

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.

390

Feathered Hollow in Living Tree  

USGS Multimedia Gallery

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

391

Logistic Model Trees + Niels Landwehr  

E-print Network

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

Frank, Eibe

392

Logistic Model Trees Niels Landwehr  

E-print Network

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

Frank, Eibe

393

Statistical Methods for Evolutionary Trees  

PubMed Central

In 1963 and 1964, L. L. Cavalli-Sforza and A. W. F. Edwards introduced novel methods for computing evolutionary trees from genetical data, initially for human populations from blood-group gene frequencies. The most important development was their introduction of statistical methods of estimation applied to stochastic models of evolution. PMID:19797062

Edwards, A. W. F.

2009-01-01

394

The Right Mix of Trees  

NSDL National Science Digital Library

This video describes the work of scientists who are studying the precise combination of trees that would be most effective in reducing the level of greenhouse gases in the air around Syracuse, NY. This is a pilot study that will serve as a model for other urban areas.

New York College of Environmental Science and Forestry

395

Chopping Down the Cherry Tree.  

ERIC Educational Resources Information Center

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

Griswold, Jerry

1995-01-01

396

Selecting Landscape Plants: Shade Trees  

E-print Network

Selecting Landscape Plants: Shade Trees Diane Relf, Extension Specialist, Horticulture, Virginia for any landscape plan. They set the stage for the entire home grounds design. The type used. Many will live and enhance the landscape for 100 or more years if they are given a chance. Because

Liskiewicz, Maciej

397

A Bayes Evaluation Criterion for Decision Trees  

Microsoft Academic Search

\\u000a We present a new evaluation criterion for the induction of decision trees. We exploit a parameter-free Bayesian approach and\\u000a propose an analytic formula for the evaluation of the posterior probability of a decision tree given the data. We thus transform\\u000a the training problem into an optimization problem in the space of decision tree models, and search for the best tree,

Nicolas Voisine; Marc Boullé; Carine Hue

2009-01-01

398

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

399

Balancing minimum spanning and shortest path trees  

Microsoft Academic Search

This paper give a simple linear-time algorithm that, given a weighted\\u000adigraph, finds a spanning tree that simultaneously approximates a shortest-path\\u000atree and a minimum spanning tree. The algorithm provides a continuous\\u000atrade-off: given the two trees and epsilon > 0, the algorithm returns a\\u000aspanning tree in which the distance between any vertex and the root of the\\u000ashortest-path

Samir Khuller; Balaji Raghavacharit; Neal E. Young

1993-01-01

400

CS 331, Fall 2013 Minimum Spanning Trees  

E-print Network

CS 331, Fall 2013 Minimum Spanning Trees Tandy Warnow (most slides by Richard Anderson from Univ Washington) #12;Minimum Spanning Tree a b c s e g f 9 2 13 6 4 11 5 7 20 14 t u v 15 10 1 8 12 16 22 17 3 #12;Greedy Algorithms for Minimum Spanning Tree · Extend a tree by including the cheapest outgoing edge · Add

Warnow,Tandy

401

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.

402

Trees are Terrific...Travels with Pierre  

NSDL National Science Digital Library

This page, from the University of Illinois Extension, has an animated cartoon designed to help young children (5-8 years of age) gain an appreciation of trees, observe trees in their every day lives and develop an interest in learning more about trees. It is intended for adults to work with children to explore the wonders of trees. It meets several of the Illinois statewide learning goals for second grade. The teacher's guide includes a number of suggested activities.

403

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.

Erica Bigio

404

WHAT MAKES A BIG TREE SPECIAL? INSIGHTS FROM THE CHICAGOLAND TREEMENDOUS TREES PROGRAM  

Microsoft Academic Search

In 1995, a local version of the American Forests big trees program (Treemendous Trees) was initiated in the Chicago area by Openlands Project and the Morton Arboretum. In addition to the numerical information about tree sizes required on the nomination form, many participants attached notes and sometimes lengthy letters that detailed various aspects of the nominated trees. A qualitative analysis

Susan C. Barro; Paul H. Gobster; Herbert W. Schroeder; Stephen M. Bartram

1997-01-01

405

Using Tree Rings to Predict the Response of Tree Growth to Climate  

E-print Network

the International Tree-Ring Data Bank (ITRDB). Comparing annual tree-ring- width data from 1097 sites). The geographic distribution of climate change, however, was far from uniform within the continental United StatesUsing Tree Rings to Predict the Response of Tree Growth to Climate Change in the Continental United

Williams, Park

406

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

407

Street tree valuation systems The Capital Asset Value for Amenity Trees (CAVAT) scheme provides a method  

E-print Network

Street tree valuation systems The Capital Asset Value for Amenity Trees (CAVAT) scheme provides a method for managing trees as public assets in London. A literature and methodological review was commissioned to assess approaches to estimating the amenity value of street trees to feed into Forestry

408

ForPeerReview Tree diversity enhances tree transpiration in a Panamanian  

E-print Network

ForPeerReview Tree diversity enhances tree transpiration in a Panamanian forest plantation Journal-species stands, monoculture, native species, plot transpiration, selection effect Journal of Applied Ecology #12;ForPeerReview 1 Tree diversity enhances tree transpiration in a Panamanian forest plantation1 2

Bermingham, Eldredge

409

The Asymmetric Median Tree - A New model for Building Consensus Trees  

Microsoft Academic Search

Inferring the consensus of a set of different evolutionary trees for a given species set is a well-studied problem, for which several different models have been proposed. In this paper, we propose a new optimization problem for consensus tree construction, which we call the asymmetric median tree, (AMT). Our main theoretical result is the equivalence between the asymmetric median tree

Cynthia A. Phillips; Tandy J. Warnow

1996-01-01

410

Rounding via trees: deterministic approximation algorithms for group Steiner trees and k -median  

Microsoft Academic Search

Most optimization problems on an undirected graphreduce in complexity when restricted to instanceson a tree. A recent result [3] for probabilisticallyapproximating graph metrics by trees such that noedge stretches (in an expected sense) by more thana factor of O(log2n) has resulted in several approximationalgorithms which exploit the ease of solvingproblems on trees. The tree construction in [3] is inherentlyrandomized and

Moses Charikar; Chandra Chekuri; Ashish Goel; Sudipto Guha

1998-01-01

411

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

E-print Network

) for the extant species, the first step constructs a gene tree representing the relationships among the sequencesReconciling 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

Della Vedova, Gianluca

412

The probability distribution of ranked gene trees on a species tree James H. Degnan a,  

E-print Network

of applications. First, it provides a mathematical basis for studying the properties of gene trees in a standardThe probability distribution of ranked gene trees on a species tree James H. Degnan a, , Noah A Accepted 21 October 2011 Available online 31 October 2011 Keywords: Anomalous gene trees Coalescent

Rosenberg, Noah

413

The Trees and the Forest: Characterization of complex brain networks with minimum spanning trees.  

E-print Network

The Trees and the Forest: Characterization of complex brain networks with minimum spanning trees. C to this problem is to represent brain networks by a minimum spanning tree (MST), a unique acyclic subgraph networks, Graph theory, minimum spanning tree, functional connectivity, EEG, MEG #12; 3 Table

Van Mieghem, Piet

414

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

E-print Network

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

Rosenberg, Noah

415

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

E-print Network

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

Rosenberg, Noah

416

DOES TREE HARDNESS INFLUENCE NEST-TREE SELECTION BY PRIMARY CAVITY NESTERS?  

Microsoft Academic Search

may vary among bird species, causing nest-tree selection to vary among excavator species. We examined use of quaking aspens (Populus tremuloides) for nest trees as a function of tree hardness in four species of woodpeckers: Williamson's Sapsucker (Sphyrapicus thyroideus), Red-naped Sapsucker (S. nuchalis), Downy Woodpecker (Picoides pubescens), and Hairy Woodpecker (P. villosus). Hardness of trees was measured at 95 nest

JAKE SCHEPPS; STEVE LOHR; THOMAS E. MARTIN

417

Picking a tree: habitat use by the tree agama, Acanthocercus atricollis atricollis, in South Africa  

Microsoft Academic Search

We studied tree agama (Acanthocercus a. atricollis) habitat use in the Magaliesberg mountain range in northern South Africa using sightings of marked individuals, and in a few cases, radio-telemetry. Acanthocercus a. atricollis preferentially selected thorn trees (46%; Acacia karroo), followed by common sugarbush (10%; Protea caffra) and dead trees (9%). The type of tree selected was unrelated to lizard age

Leeann T. Reaney; Martin J. Whiting

2003-01-01

418

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.

419

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 by the Arbor Day Foundation, possesses a diverse and rich variety of trees on its campuses. CSU Facilities has maintained and inventoried these trees over the years, with periodic support from students in horticulture

420

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

421

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

422

Effect of tree channel conductivity on electrical tree shape and breakdown in XLPE cable insulation samples  

Microsoft Academic Search

The results of an investigation into electrical tree growth in XLPE cable insulation using an embedded needle electrode are reported for a range of voltages from 9 kV rms to 27 kV rms. The partial discharge (PD) activity and tree structures were measured simultaneously throughout the tree growth and the trees were recorded from initiation up to and including the

Xiangrong Chen; Yang Xu; Xiaolong Cao; S. J. Dodd; L. A. Dissado

2011-01-01

423

On Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses  

E-print Network

it. Similarly, in a species tree, an ancient species is defined by the con­ temporary speciesOn Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses Bin Ma \\Lambda ancestors mapping, the duplication and mutation costs, and the complexity of finding a species tree from

Page, Roderic

424

On Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses  

E-print Network

it. Similarly, in a species tree, an ancient species is de ned by the con- temporary speciesOn Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses Bin Ma , Ming ancestors mapping, the duplication and mutation costs, and the complexity of nding a species tree from gene

Page, Roderic

425

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 Contents ACKNOWLEDGMENTS SUMMARY Trees in the Urban Environment-27 #12;Portland State University ­ CSAR Street Trees in the Urban Forest Canopy ACKNOWLEDGMENTS

Poracsky, Joseph

426

Hardwood Tree Improvement and Regeneration Center  

E-print Network

FNR-213 Hardwood Tree Improvement and Regeneration Center North Central Research Station USDA Forest Service Department of Forestry and Natural Resources Purdue University Designing Hardwood Tree Woody plants can be of value to many wildlife species. The species of tree or shrub, or the location

427

TREE MAINTENANCE AND REMOVAL Table Of Contents  

E-print Network

EM 385-1-1 XX Sep 13 i Section 31 TREE MAINTENANCE AND REMOVAL Table Of Contents Section: Page 31.A General................... ......................................................31-1 31.B Tree Climbing.................................31-14 #12;EM 385-1-1 XX Sep 13 31-1 SECTION 31 TREE MAINTENANCE AND REMOVAL 31. A GENERAL 31.A.01

US Army Corps of Engineers

428

Dynamic Segment Trees for Ranges and Prefixes  

Microsoft Academic Search

In this paper, we develop a segment tree data structure for solving dynamic table lookup problems. The proposed dynamic segment tree (DST) uses all distinct endpoints of ranges as the keys based on a new range endpoint scheme. The new endpoint scheme generates fewer endpoints than the traditional endpoint scheme. DST is implemented as a balanced binary search tree augmented

Yeim-kuan Chang; Yung-chieh Lin

2007-01-01

429

TREES OF GENES IN POPULATIONS Joseph Felsenstein  

E-print Network

1 TREES OF GENES IN POPULATIONS Joseph Felsenstein Abstract Trees of ancestry of copies of genes appears thin. If each of these thin lines truly contained only one copy of this gene's sequence, we would and more important to evolutionary genetics. #12;4 Trees of genes in populations To explain how population

Borenstein, Elhanan

430

Fuzzy quadratic minimum spanning tree problem  

E-print Network

Fuzzy quadratic minimum spanning tree problem Jinwu Gao *, Mei Lu Department of Mathematical the effectiveness of the genetic algorithm. Ã? 2004 Published by Elsevier Inc. Keywords: Minimum spanning tree; Fuzzy programming; Genetic algorithm; Credibility measure 1. Introduction The minimum spanning tree (MST) problem

Lu, Mei

431

Approximating Spanning Tree with Weighted Inner Nodes  

E-print Network

a minimum spanning tree with both edge weights and inner node (non-leaf node) weights. This problem is NP is the maximum degree of the graph. Keywords: Minimum spanning tree, approximation algorithm, NP-hard 1 Introduction 1.1 Problem Statement Minimum spanning trees have been widely studied and many efficient

432

Distinguished The Minimum Label Spanning Tree  

E-print Network

Distinguished 2006 Series The Minimum Label Spanning Tree Problem: Illustrating the Power a connected, undirected graph G whose edges are labeled (or colored), the minimum label spanning tree (MLST) problem seeks a spanning tree on G with the minimum number of distinct labels (or colors). The MLST

Aydilek, Ahmet

433

Brief Contributions________________________________________________________________________________ Distributed Minimum Spanning Tree  

E-print Network

________________________________________________________________________________ Distributed Minimum Spanning Tree Maintenance for Transient Node Failures Paola Flocchini, T. Mesa Enriquez, the computation takes place on the minimum-cost spanning tree (MST) of the network G; unfortunately, a single link consider for the first time the problem of computing all the replacement minimum-cost spanning trees

Prencipe, Giuseppe

434

Multiple criteria minimum spanning trees Pedro Cardoso  

E-print Network

Multiple criteria minimum spanning trees Pedro Cardoso M´ario Jesus ´Alberto M´arquez Abstract The NP multiple criteria minimum spanning tree as several applications into the network design problems criteria minimum spanning trees. There are several geometric network design and application problems

Coello, Carlos A. Coello

435

Parametric and Kinetic Minimum Spanning Trees  

Microsoft Academic Search

We consider the parametric minimum spanning tree problem, in which we are given a graph with edge weights that are linear functions of a parameter‚ and wish to com- pute the sequence of minimum spanning trees generated as‚ varies. We also consider the kinetic minimum spanning tree problem, in which‚ represents time and the graph is subject in addition to

Pankaj K. Agarwal; David Eppstein; Leonidas J. Guibas; Monika Rauch Henzinger

1998-01-01

436

Maintaining Minimum Spanning Trees in Dynamic Graphs  

E-print Network

Maintaining Minimum Spanning Trees in Dynamic Graphs Monika R. Henzinger 1 and Valerie King 2 1 for maintaining a minimum spanning tree in time o( p n) per operation. To be precise, the algorithm uses O(n 1 We consider the problem of maintaining a minimum spanning tree during an arbitrary sequence of edge

King, Valerie

437

a buyer's guide Trees for Conservation  

E-print Network

a buyer's guide Trees for Conservation #12;ii Many thanks to Dennis Will, Dan Wand, Greg Morgenson #115-1196 The Colorado State Forest Service tree program enables farmers, ranchers and rural landowners to obtain trees at nominal cost. The program's aim is to encourage landowners to plant new forests

438

Merging BSP trees yields polyhedral set operations  

Microsoft Academic Search

BSP trees have been shown to provide an effective representation of polyhedra through the use of spatial subdivision, and are an alternative to the topologically based b-reps. While bsp tree algorithms are known for a number of important operations, such as rendering, no previous work on bsp trees has provided the capability of performing boolean set operations between two objects

Bruce F. Naylor; John Amanatides; William C. Thibault

1990-01-01

439

Decision Tree Validation: A Comprehensive Approach  

Microsoft Academic Search

Ever since the availability of data mining tools, decision trees have been popular because they are simple to use and easy to interpret. Producing decision trees is straightforward, but evaluating them can be a challenge. In predictive modeling, overfitting is always a danger. A good decision tree must generalize the trends in the data, and this is why the assessment

Sylvain Tremblay

440

Malcolm Guite The Magic Apple Tree  

E-print Network

Malcolm Guite The Magic Apple Tree Someday make a journey through the rain Through sodden streets in darkening December A journey to the magic apple tree. And journey also, darkling, through your past Journey records. You glimpsed it once within the garden wall, The image of an ancient apple tree, The fall

Robertson, Stephen

441

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

442

A general bijective algorithm for trees.  

PubMed Central

Trees are combinatorial structures that arise naturally in diverse applications. They occur in branching decision structures, taxonomy, computer languages, combinatiorial optimization, parsing of sentences, and cluster expansions of statistical mechanics. Intuitively, a tree is a collection of branches connected at nodes. Formally, it can be defined as a connected graph without cycles. Schroder trees, introduced in this paper, are a class of trees for which the set of subtrees at any vertex is endowed with the structure of ordered partitions. An ordered partition is a partition of a set in which the blocks are linearly ordered. Labeled rooted trees and labeled planed trees are both special classes of Schroder trees. The main result gives a bijection between Schroder trees and forests of small trees--namely, rooted trees of height one. Using this bijection, it is easy to encode a Schroder tree by a sequence of integers. Several classical algorithms for trees, including a combinatorial proof of the Lagrange inversion formula, are immediate consequences of this bijection. PMID:11607133

Chen, W Y

1990-01-01

443

Genomics of Tropical Fruit Tree Crops  

Technology Transfer Automated Retrieval System (TEKTRAN)

The genetic improvement of tropical fruit trees is limited when compared to progress achieved in temperate fruit trees and annual crops. Tropical fruit tree breeding programs require significant resources to develop new cultivars that are adapted to modern shipping and storage requirements. The use...

444

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.

445

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

446

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

447

Recommended Trees for Plains Communities of  

E-print Network

Recommended Trees for Plains Communities of Northeastern Colorado A Guide for Selecting, Planting, and Caring For Trees #12;Special thanks to the International Society of Arboriculture for providing details trees. Topping leads to: · Starvation · Shock · Insects and diseases · Weak limbs · Rapid new growth

448

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

449

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

450

Recommended Trees for Plains Communities of  

E-print Network

Recommended Trees for Plains Communities of Southeastern Colorado A Guide for Selecting, Planting, and Caring For Trees #12;Special thanks to the International Society of Arboriculture for providing details trees. Topping leads to: · Starvation · Shock · Insects and diseases · Weak limbs · Rapid new growth

451

Recommended Trees for Colorado Front Range  

E-print Network

Recommended Trees for Colorado Front Range Communities A Guide for Selecting, Planting, and Caring For Trees #12;Special thanks to the International Society of Arboriculture for providing details trees. Topping leads to: · Starvation · Shock · Insects and diseases · Weak limbs · Rapid new growth

452

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

453

Recommended Trees for Plains Communities of  

E-print Network

Recommended Trees for Plains Communities of Eastern Colorado A Guide for Selecting, Planting, and Caring For Trees #12;Special thanks to the International Society of Arboriculture for providing details trees. Topping leads to: · Starvation · Shock · Insects and diseases · Weak limbs · Rapid new growth

454

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

455

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.

456

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

457

Hierarchies of Tree Series Transformations Andreas Maletti  

E-print Network

class. 1 Introduction Tree series transducers were introduced in [1­3] as a generalization of top-down transfor- mations on tree series became interesting. For example, in [11] the power of (top-down) tree series transducers for natural language processing was recognized. In the seminal paper [12

Reyle, Uwe

458

4, 249270, 2008 Tree-ring analysis  

E-print Network

CPD 4, 249­270, 2008 Tree-ring analysis and droughts in northwestern France O. Planchon et al forum of Climate of the Past Contribution of tree-ring analysis to the study of droughts in northwestern on behalf of the European Geosciences Union. 249 #12;CPD 4, 249­270, 2008 Tree-ring analysis and droughts

Brest, Université de

459

Tree Rings in Archaeology, Climatology and Ecology  

E-print Network

TRACE Tree Rings in Archaeology, Climatology and Ecology Volume 10 Proceedings, tree-ring investigations of abandoned oak coppice have been recently undertaken on both sides between trees generated from stool and from acorns. (2) Influence of degree of competition and social

Paris-Sud XI, Université de

460

Tree Rings in Archaeology, Climatology and Ecology  

E-print Network

TRACE Tree Rings in Archaeology, Climatology and Ecology Volume 11 Proceedings:nbn:de:kobv:b103-13058 #12;Preface This publication is a result of the 11th TRACE conference (Tree Ringsth 2012 in Potsdam and Eberswalde, Germany. TRACE is an initiative of the `Association of Tree-Ring

Biondi, Franco

461

Tree rings, carbon dioxide, and climatic change  

Microsoft Academic Search

Tree rings have been used in various appli- cations to reconstruct past climates as well as to assess the effects of recent climatic and environmental change on tree growth. In this paper we brief ly review two ways that tree rings provide information about climate change and CO2 :( i )i n determining whether recent warming during the period of

GORDON C. JACOBY; ROSANNE D. D'ARRIGO

1997-01-01

462

Tree Rings, Carbon Dioxide, and Climatic Change  

Microsoft Academic Search

Tree rings have been used in various applications to reconstruct past climates as well as to assess the effects of recent climatic and environmental change on tree growth. In this paper we briefly review two ways that tree rings provide information about climate change and CO2: (i) in determining whether recent warming during the period of instrumental observations is unusual

Gordon C. Jacoby; Rosanne D. D'Arrigo

1997-01-01

463

Temperature histories from tree rings and corals  

Microsoft Academic Search

Recent temperature trends in long tree-ring and coral proxy temperature histories are evaluated and compared in an effort to objectively determine how anomalous twentieth century temperature changes have been. These histories mostly reflect regional variations in summer warmth from the tree rings and annual warmth from the corals. In the Northern Hemisphere, the North American tree-ring temperature histories and those

Edward R Cook

1995-01-01

464

Site Design Guidelines CAMPUS TREE LIST 1  

E-print Network

to ground with minimum height of 8' Evergreen and Screen Trees: 1. Cedrus deodara ­ Deodar Cedar 2 Lawn Trees 1. Acer saccharum ­ Sugar Maple 2. Acer rubrum ­ Red Maple 3. Aesculus x carnea leleaf Linden Columnar Trees 1. Acer Rubrum `Armstrong' - Red Maple 2. Acer Rubrum `Columnare

Duchowski, Andrew T.

465

Trees and Shrubs in Northwest Texas.  

E-print Network

....------_-----..---..------------------------------------------.-------....-.~.----...-----~..-. Evergreen. Trees __._..._______._.._...--__.-_._-__-__-_.-------------------------.._--__-_______.__.-___ Eastern Red Cedar Western Red Cedar .._-____-----_-----------..-..-------.------------------------..----------.-----.. Chinese Juniper -- -- Pfitzer... japonica) 8. Mock Orange (Philadelphus coronarizt s) 9. Smoke Tree (Rhics cotinus) Trees and Shrubs Suitable for Herd5ges Trimmed 1. Chinese arborvitae ( Thuja orientalis) 2. Red Cedar (Juniperus virginianm) 3. Amur River Privet (Ligustrum ami...

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

1932-01-01

466

Cache-oblivious dynamic search trees  

E-print Network

I have implemented a cache-oblivious dynamic search tree as an alternative to the ubiquitious B-tree. I use a binary tree with a "van Endcle Boas" layout whose leaves point to intervals in a "packed memory structure". We ...

Kasheff, Zardosht, 1981-

2004-01-01

467

The Information Content of Consensus Trees  

Microsoft Academic Search

Phylogenetic Information Content, a class of measures of the information provided by consensus trees based on the number of permitted resolutions of the consensus, is introduced. A formula for the number of permitted resolutions of Adams consensus trees is derived and a proof given. We argue that maximising PIC measures provides a sensible criterion for choosing among alternative consensus trees

Joseph L. Thorley; Mark Wilkinson; Mike Charleston

468

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

469

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

470

When Bad Things Happen to Good Trees  

E-print Network

for both trees and rooted trees, one of which is especially simple in each case. We also prove two extremal, but a sudden power surge, or earthquake, or tornado, or asteroid,F F F disables some of these edges. What trees, it is more dif®cult to motivate a reliability interpretation in the unrooted case. We propose

Gordon, Gary

471

VERTEBRATE PHYLOGENOMICS: RECONCILED TREES AND GENE DUPLICATIONS  

E-print Network

VERTEBRATE PHYLOGENOMICS: RECONCILED TREES AND GENE DUPLICATIONS R.D.M. PAGE, J.A. COTTON Division-mail: r.page@bio.gla.ac.uk Ancient gene duplication events have left many traces in vertebrate genomes. Rec- onciled trees represent the differences between gene family trees and the species phylogeny those

Page, Roderic

472

The Galileo Fault Tree Analysis Tool  

Microsoft Academic Search

We present Galileo, a dynamic fault tree modeling and analysis tool that combines the innovative DIF- Tree analysis methodology with a rich user interface built using package-oriented programming. DIFTree integrates binary decision diagram and Markov meth- ods under the common notation of dynamic fault trees, allowing the user to exploit the benefits of both tech- niques while avoiding the need

Kevin J. Sullivan; Joanne Bechta Dugan; David Coppit

1999-01-01

473

Assessing Damage and RestoringTrees  

E-print Network

Assessing Damage and RestoringTrees After a HurricaneUrban Forest Hurricane Recovery Program ENH Trees After a Hurricane Urban Forest Hurricane Recovery Program Acknowledgments: #12;Storm damage Cleaning the canopy: The red lines indicate where to make pruning cuts on this tree. Make good pruning cuts

Florida, University of

474

Modeling Trees with a Space Colonization Algorithm  

Microsoft Academic Search

We extend the open leaf venation model by Runions et al. (RFL 05) to three dimensions and show that it gener- ates surprisingly realistic tree structures. Model parameters correspond to visually relevant tree characteristics identified in landscaping, offering convenient control of tree shape and structure.

Adam Runions; Przemyslaw Prusinkiewicz

2007-01-01

475

Progress report Rolling stones and tree rings  

E-print Network

Progress report Rolling stones and tree rings: A state of research on dendrogeomorphic Abstract This progress report focuses on the contribution of tree-ring series to rockfall research since the early 2000s and several approaches have been developed to extract rockfall signals from tree-ring

Stoffel, Markus

476

The RD-tree Allowing Data in Interior Nodes of the R-tree  

Microsoft Academic Search

The RD-tree is a dynamic spatial access method which is a variant of the R-tree. The major difference between the R-tree and the RD-tree is the use of the RD-tree's interior nodes, which contains not only index entries but also data entries whenever possible. When an appropriate data object is stored in an interior node, instead of a leaf node

Tanin Na Nakorn; Jaruloj Chongstitvatana

2006-01-01

477

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

478

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

479

Survey: Tree Transducers in Machine Translation Andreas Maletti  

E-print Network

of regularity, and closure under composition. For three tree transducer models, top-down tree transducers, extended top-down tree transducers, and extended multi bottom-up tree transducers, the relevant results] and computational linguistics [33, 27] started on a common basis. The first tree-transducer model, the top-down tree

Reyle, Uwe

480

Recognition of directed acyclic graphs by spanning tree automata  

Microsoft Academic Search

In this paper, we study tree automata for directed acyclic graphs (DAGs). We define the movement of a tree automaton on a DAG so that a DAG is accepted by a tree automaton if and only if the DAG has a spanning tree accepted by the tree automaton. We call this automaton a spanning tree automaton. The NP-completeness of the

Akio Fujiyoshi

2010-01-01

481

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

482

Inferring species trees from incongruent multi-copy gene trees using the Robinson-Foulds distance  

PubMed Central

Background Constructing species trees from multi-copy gene trees remains a challenging problem in phylogenetics. One difficulty is that the underlying genes can be incongruent due to evolutionary processes such as gene duplication and loss, deep coalescence, or lateral gene transfer. Gene tree estimation errors may further exacerbate the difficulties of species tree estimation. Results We present a new approach for inferring species trees from incongruent multi-copy gene trees that is based on a generalization of the Robinson-Foulds (RF) distance measure to multi-labeled trees (mul-trees). We prove that it is NP-hard to compute the RF distance between two mul-trees; however, it is easy to calculate this distance between a mul-tree and a singly-labeled species tree. Motivated by this, we formulate the RF problem for mul-trees (MulRF) as follows: Given a collection of multi-copy gene trees, find a singly-labeled species tree that minimizes the total RF distance from the input mul-trees. We develop and implement a fast SPR-based heuristic algorithm for the NP-hard MulRF problem. We compare the performance of the MulRF method (available at http://genome.cs.iastate.edu/CBL/MulRF/) with several gene tree parsimony approaches using gene tree simulations that incorporate gene tree error, gene duplications and losses, and/or lateral transfer. The MulRF method produces more accurate species trees than gene tree parsimony approaches. We also demonstrate that the MulRF method infers in minutes a credible plant species tree from a collection of nearly 2,000 gene trees. Conclusions Our new phylogenetic inference method, based on a generalized RF distance, makes it possible to quickly estimate species trees from large genomic data sets. Since the MulRF method, unlike gene tree parsimony, is based on a generic tree distance measure, it is appealing for analyses of genomic data sets, in which many processes such as deep coalescence, recombination, gene duplication and losses as well as phylogenetic error may contribute to gene tree discord. In experiments, the MulRF method estimated species trees accurately and quickly, demonstrating MulRF as an efficient alternative approach for phylogenetic inference from large-scale genomic data sets. PMID:24180377

2013-01-01

483

Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative  

Microsoft Academic Search

Urban forests are increasingly being seen as an important infrastructure that can help cities remediate their environmental\\u000a impacts. This work reports on the first steps in implementing a million tree program in Los Angeles and the ways such a biogenic—living—infrastructure\\u000a has been approached. Numbers of studies have been done to quantify the benefits of urban forests, but little has been

Stephanie Pincetl

2010-01-01

484

FastTree: computing large minimum evolution trees with profiles instead of a distance matrix.  

PubMed

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 ) memory and O(N log (N)La) 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 h and 2.4 GB of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 h and 50 GB 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. PMID:19377059

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

2009-07-01

485

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

486

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

487

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

488

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

489

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

490

Fluid forces acting on a tree  

NASA Astrophysics Data System (ADS)

Flow and fluid forces acting on several kind of trees in large scale wind tunnel were measured by using wind flow velocity meter and load cell. Drag coefficient of drag forces acting on a tree decreased with increase of Reynolds number because projected frontal area of tree canopy in still air decreased with increase of incident flow velocity. The reverse flow was not found at down stream region of tree under the influence of the flow passing through the tree canopy. The recovery of flow velocity in the wake of tree was more slow compare to that of circular cylinder in uniform flow. The impulsive forces acting on a pine tree were also measured.

Hayashi, Kenjirou; Tatuno, Masakazu; Nagabayashi, Hisao; Hasimoto, Haruyuki; Tada, Tuyosi

491

Qubit semantics and quantum trees  

E-print Network

In the qubit semantics the \\emph{meaning} of any sentence $\\alpha$ is represented by a \\emph{quregister}: a unit vector of the $n$--fold tensor product $\\otimes^n \\C^2$, where $n$ depends on the number of occurrences of atomic sentences in $\\alpha$. The logic characterized by this semantics, called {\\it quantum computational logic} (QCL), is {\\it unsharp}, because the non-contradiction principle is violated. We show that QCL does not admit any logical truth. In this framework, any sentence $\\alpha$ gives rise to a \\emph{quantum tree}, consisting of a sequence of unitary operators. The quantum tree of $\\alpha$ can be regarded as a quantum circuit that transforms the quregister associated to the atomic subformulas of $\\alpha$ into the quregster associated to $\\alpha$.

M. L. Dalla Chiara; R. Giuntini; R. Leporini; A. Leporati

2003-06-01

492

Simplicial matrix-tree theorems  

E-print Network

?(G)= ? 1 ···? n?1 n . (2) For 1 ? i ? n,letL i be the reduced Laplacian obtained from L by deleting the i th row and i th column. Then ?(G)=detL i . Well-known corollaries of the Matrix-Tree Theorem include Cayley’s formula [9] (1) ?(K n )=n n?2... , introducing indeterminates x 1 ,...,x n and set- ting e ij = x i x j for all i, j yields the Cayley-Pr¨ufer Theorem, which enumerates spanning trees of K n by their degree sequences: (3) summationdisplay T?T (G) n productdisplay i=1 x deg T (i) i = x 1 ···x n...

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

2009-01-01

493

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

494

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

495

Zinc Fertilization of Avocado Trees  

Microsoft Academic Search

Methods for Zn fertilization of 'Hass' avocado (Persea americana Mill.) trees were evaluated in a 2-year field experiment on a commercial orchard located on a calcareous soil (pH 7.8) in Ventura County, Calif. The fertilization methods included soil- or irrigation-applied ZnSO4; irrigation-applied Zn chelate (Zn- EDTA); trunk injection of Zn(NO3)2, and foliar applications of ZnSO4, ZnO, or Zn metalosate. Other

David E. Crowley; Woody Smith

496

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.

497

Factoring with the Factor Tree  

NSDL National Science Digital Library

This Java applet presents a composite number, and prompts you to factor it -- one step at a time. Enter one factor, prime or another composite; the applet calculates the remaining factor, and branches two boxes below any composite factor so that you may proceed factoring until you obtain the full factorization into primes, which the applet colors in green. Click the "Repeat problem" button to see that different factor trees for a given number still result in the same prime factorization.

Interactive Math Miscellany and Puzzles, Alexander Bogomolny

2011-01-01

498

Game Trees for Decision Analysis  

E-print Network

[1990], Smith, Holtzman and Matheson [1993], Kirkwood [1993], and Covaliu and Oliver [1995] examine hybrid representation methods that combine influence diagrams and decision trees. Shenoy [1993b] describes an efficient generalization of the valuation..., 719-762, Strategic Decisions Group, Menlo Park, CA. Kirkwood, C. W. (1993), ?An algebraic approach to formulating and solving large models for sequential decisions under uncertainty,? Management Science, 39(7), 900?913. References 19 Kreps, D. and R...

Shenoy, Prakash P.

1998-04-01

499

Optimal PIF in Tree Networks  

Microsoft Academic Search

In this paper, we consider rooted tree networks, as well as tr ees with- out sense of direction. We propose a new PIF scheme, called Propagation of Information with Feedback and Cleaning(PFC ). We present both self- stabilizing and snap-stabilizingPFC algorithms. A self-stabilizing system, regardless of the initial states of the processors and initi al messages in the links, is

Alain Bui; Ajoy Kumar Datta; Franck Petit; Vincent Villain

1999-01-01

500

Dendrochemistry: Seeing the forest through the trees  

NASA Astrophysics Data System (ADS)

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

Hauck, Danielle K.