These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
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

"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 species, is causing Ganoderma root rot on the Jacaranda trees in Pretoria. #12;2 Vuledzani investigating

4

Tree Volume Equations for 10 Urban Species in California1  

Microsoft Academic Search

This study is the first phase of a three-phase urban forest utilization project at California Polytechnic State University, San Luis Obispo. Selected samples of 10 urban species were carefully measured in order to develop tree volume equations. These species include Chinese elm, holly oak, camphor tree, jacaranda, American sweet gum, Monterey pine, blue gum, Monterey cypress, acacia (golden wattle), and

Norman H. Pillsbury; Jeffrey L. Reimer

5

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.

6

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

7

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

Guimaraes, Elza; di Stasi, Luiz Claudio; Maimoni-Rodella, Rita de Cassia Sindronia

2008-01-01

8

Antioxidant and Cytotoxic Activity of Hydroethanolic Extract from Jacaranda decurrens Leaves  

PubMed Central

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

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

2014-01-01

9

Induction of apoptotic cell death in HL-60 cells by jacaranda seed oil derived fatty acids.  

PubMed

Various fatty acids are attracting considerable interest for their anticancer effects. Among them, fatty acids containing conjugated double bonds show one of the most potent cytotoxic effects on cancer cells. Here, we focused on the cancer cell killing activity of jacaranda seed oil. The seed oil of jacaranda harvested from Miyazaki in Japan contained 30.9% cis-8, trans-10, cis-12 octadecatrienoic acid, called jacaric acid (JA). Fatty acid prepared from this oil (JFA) and JA strongly induced cell death in human leukemia HL-60 cells. On the other hand, linoleic acid and trans-10, cis-12 conjugated linoleic acid (<10 ?M) did not affect cell proliferation and viability. An increase in the sub-G? population and internucleosomal fragmentation of DNA was observed in JA- and JFA-treated cells, indicating induction of apoptotic cell death. Finally, the cytotoxic effects of JA and JFA were completely abolished by ?-tocopherol. Taken together, these data suggest that jacaranda seed oil has potent apoptotic activity in HL-60 cells through induction of oxidative stress. PMID:24200941

Yamasaki, Masao; Motonaga, Chihiro; Yokoyama, Marino; Ikezaki, Aya; Kakihara, Tomoka; Hayasegawa, Rintaro; Yamasaki, Kaede; Sakono, Masanobu; Sakakibara, Yoichi; Suiko, Masahito; Nishiyama, Kazuo

2013-01-01

10

Phenolic compounds from Jacaranda caroba (Vell.) A. DC.: approaches to neurodegenerative disorders.  

PubMed

Diseases affecting the central nervous system are spread throughout the world. As so, more efficient and safe neuroprotective drugs are required. The present study describes, for the first time, the phenolic composition and bioactivity of Jacaranda caroba (Vell.) A. DC, a species whose infusion is consumed as traditional medicine. The HPLC-DAD-ESI/MS(n) analysis revealed the presence of four dicaffeoyl acid derivatives and nine flavonoids, comprising quercetin, kaempferol and isorhamnetin derivatives. Twelve compounds are described for the first time in Jacaranda genus. Although isorhamnetin-3-O-rhmanoside-7,4'-di-O-glucoside and quercetin-3-O-(2-pentosyl)hexoside are the main metabolites in both aqueous and hydromethanolic extracts, qualitative and quantitative differences were found between them. Aqueous extract is richer in dicaffeoyl acid derivatives. Both extracts proved to be strong radicals' scavengers and effective monoamine-oxidase A inhibitors, but showed weak protection against cholinesterases' activity. The results highlight the value of J. caroba as a source of health-promoting antioxidants and antidepressant compounds. PMID:23524314

Ferreres, Federico; Grosso, Clara; Gil-Izquierdo, Angel; Valentão, Patrícia; Andrade, Paula B

2013-07-01

11

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

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

Maple tree  

NSDL National Science Digital Library

Trees give animals shade and a place to live and hide. Trees give many animals food. They also take in carbon dioxide, which animals breathe out, and replace it with oxygen, which is what animals need to breathe.

Derek Ramsey (None;)

2006-09-23

14

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

15

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

16

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

17

Tree Talk  

NSDL National Science Digital Library

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

Rosen, S.

2010-01-01

18

Global Changes And Tree Growth Rate In The Amazon Forest  

NASA Astrophysics Data System (ADS)

A better understanding of the variations in the dynamics and structure of trees in tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon. In general, tropical forests have been treated as if all trees behaved similarly, and little is known about how forests vary across the large extent of the Amazon basin. Our data show large differences in forest structure, biomass, and tree growth rates among plots under study in three locations in Brazil: ZF-2 Bionte/Jacaranda plots \\(Manaus\\), Catuaba Reserve \\(Rio Branco\\), and Tapaj¢s National Forest \\(Santarém\\). These locations span an east-west transect of the Amazon basin with different dry-season lengths. The number of stems >10cm diameter and stocks of C in aboveground biomass are the highest in Manaus \\(626ha-1, 180.1Mg.C.ha-1\\), than Rio Branco \\(466ha-1, 122.1Mg.C.ha-1\\) or Santarém \\(460ha-1, 140.6Mg.C.ha-1\\). Estimates of mean annual accumulation of C ranged from 1.6 \\(Manaus\\) and 2.5 \\(Rio Branco\\) to 2.8Mg.C.ha-1.yr-1 \\(Santarém\\). Trees in the 10-30cm diameter-size showed the highest accumulation of C \\(38%, 55%, and 56% - Manaus, Rio Branco, and Santarém, respectively\\). Our results showed marked seasonal growth, with the highest growth rates in the wet-season and the lowest growth rates in the dry-season. This effect was most evident for trees with diameter >50cm. The comparison of the three areas investigated suggests that forests experiencing a longer dry-season have larger annual diameter growth increments for individual trees. Tree average age was larger in Manaus where the increment was smaller. In all the three areas it was found specimens with DBH smaller than 30cm, but with ages over 200 years. It was found a specimen of 17 cm of DBH and age of 920 years. The fact that small trees can reach old ages may alter the scope of the present forest management planning whose focus is tree species of economical interest and the time the take to reach a commercial diameter.

Camargo, P. B.; Vieira, S. A.; Trumbore, S. E.

2003-12-01

19

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.

Playground, Math

2009-07-29

20

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

21

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

22

Audubon Tree Study Program.  

ERIC Educational Resources Information Center

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

National Audubon Society, New York, NY.

23

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.

Addison, Keith

2010-01-01

24

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

25

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

26

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.

27

Tree2 - Decision Trees for Tree Structured Data  

Microsoft Academic Search

We present Tree2, a new approach to struc- tural classic ation. This integrated approach induces decision trees that test for pattern occurrence in the inner nodes. It combines state-of-the-art tree mining with sophisti- cated pruning techniques to nd the most discriminative pattern in each node. In con- trast to existing methods, Tree2 uses no heuristics and only a single, statistically

Björn Bringmann; Albrecht Zimmermann

2005-01-01

28

American Chestnut Tree  

NSDL National Science Digital Library

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

Ket

2008-09-02

29

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.

30

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.

31

Tree Decline Shade trees often gradually lose  

E-print Network

affecting root systems. Be- cause these changes often are caused by human activities, they are often. Common examples include planting pin oak in soils with a high pH (pH 7.0+) or white pine in poorly of the tree. 3. Maintain tree health. Water and fertilize trees as needed. With normal rainfall

32

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

33

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

34

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

35

Evolution of Decision Trees  

Microsoft Academic Search

This paper addresses the issue of the induction of orthogonal, oblique and mul- tivariate decision trees. Algorithms pro- posed by other researchers use heuristic, usually based on the information gain con- cept, to induce decision trees greedily. These algorithms are often tailored for a given tree type (e.g orthogonal), not be- ing able to induce other types of decision trees.

Xavier Llor; Josep M. Garrelly

36

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

37

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

38

Fault-Tree Compiler  

NASA Technical Reports Server (NTRS)

Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

Butler, Ricky W.; Boerschlein, David P.

1993-01-01

39

GA Tree: genetically evolved decision trees  

Microsoft Academic Search

We e xplore the use of genetic algorithms to directly evolve classification decision trees. Instead of using binary strings, we a dopt a natural representation of the problem using binary tree structures. We argue on the suitability of such a concept learner due to its ability to efficiently search complex hypotheses s paces and discover conditionally dependent as well as

Athanassios Papagelis; Dimitrios Kalles

2000-01-01

40

Advisory Note TREE HEALTH  

E-print Network

pest Advisory Note TREE HEALTH March 2007 Gypsy Moth Lymantria dispar (Lepidoptera: Lymantridae) Gypsy moth, Lymantria dispar, is an important defoliator of a very wide range of trees and shrubs in mainland

41

Evolution of tree nutrition.  

PubMed

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

Raven, John A; Andrews, Mitchell

2010-09-01

42

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.

43

Training Tree Transducers  

Microsoft Academic Search

Many probabilistic models for natural language are now written in terms of hierarchical tree structure. Tree-based modeling still lacks many of the standard tools taken for granted in (finite-state) string-based modeling. The theory of tree transducer automata provides a possible framework to draw on, as it has been worked out in an extensive literature. We motivate the use of tree

Jonathan Graehl; Kevin Knight; Jonathan May

2008-01-01

44

Extremely randomized trees  

Microsoft Academic Search

This paper proposes a new tree-based ensemble method for supervised classifica- tion and regression problems. It essentially consists of randomizing strongly both attribute and cut-point choice while splitting a tree node. In the extreme case, it builds totally random- ized trees whose structures are independent of the output values of the learning sample. The strength of the randomization can be

Pierre Geurts; Damien Ernst; Louis Wehenkel

2006-01-01

45

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

46

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

47

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

48

Training Tree Transducers  

Microsoft Academic Search

Many probabilistic models for natural language are now written in terms of hierarchical tree structure. Tree-based modeling still lacks many of the standard tools taken for granted in (finite- state) string-based modeling. The theory of tree transducer automata provides a possible frame- work to draw on, as it has been worked out in an extensive literature. We motivate the use

Jonathan Graehl; Kevin Knight

2004-01-01

49

Logistic Model Trees  

Microsoft Academic Search

Tree induction methods and linear models are popular techniques for supervised learning tasks, both for the prediction of nominal classes and numeric values. For predicting numeric quantities, there has been work on combining these two schemes into ‘model trees’, i.e. trees that contain linear regression functions at the leaves. In this paper, we present an algorithm that adapts this idea

Niels Landwehr; Mark Hall; Eibe Frank

2005-01-01

50

Logistic Model Trees  

Microsoft Academic Search

Tree induction methods and linear models are popular techniques for supervised learning tasks, both for the prediction of nominal classes and numeric values. For predicting numeric quantities, there has been work on combining these two schemes into 'model trees', i.e. trees that contain linear regression functions at the leaves. In this paper, we present an algorithm that adapts this idea

Niels Landwehr; Mark Hall; Eibe Frank

2003-01-01

51

Multivariate Decision Trees  

Microsoft Academic Search

Unlike a univariate decision tree, a multivariate decision tree is not restricted to splits of the instance space that are orthogonal to the features' axes. This article addresses several issues for constructing multivariate decision trees: representing a multivariate test, including symbolic and numeric features, learning the coefficients of a multivariate test, selecting the features to include in a test, and

Carla E. Brodley; Paul E. Utgoff

1995-01-01

52

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.

53

EVOLVING ORTHOGONAL DECISION TREES  

Microsoft Academic Search

Instead of using or flne-tuning the well-known greedy methods to induce decision trees, we propose a new method, which explores the 'brute' force of evolutionary algorithms to evolve decision trees, used mainly for classiflcation. MEP, a new evolutionary technique is used for representing the decision trees. The paper is organized as follows: the introduction makes a short overview of the

D. DUMITRESCU

2003-01-01

54

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

55

Reversible adaptive trees.  

PubMed

We describe reversible adaptive trees, a class of stochastic algorithms modified from the formerly described adaptive trees. They evolve in time a finite subset of an ambient Euclidean space of any dimension, starting from a seed point and, accreting points to the evolving set, they grow branches towards a target set which can depend on time. In contrast with plain adaptive trees, which were formerly proven to have strong convergence properties to a static target, the points of reversible adaptive trees are removed from the tree when they have not been used recently enough in a path from the root to an accreted point. This, together with a straightening process performed on the branches, permits the tree to follow some moving targets and still remain adapted to it. We then discuss in what way one can see such reversible trees as a model for a qualitative property of resilience, which leads us to discuss qualitative modeling. PMID:23934230

Kergosien, Yannick L

2013-09-01

56

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.

57

In Focus: The Tree  

NSDL National Science Digital Library

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

58

Decision Tree Induction Based on Efficient Tree Restructuring  

Microsoft Academic Search

The ability to restructure a decision tree efficiently enables a variety of approaches to decision tree induction that would otherwise be prohibitively expensive. Two such approaches are described here, one being incremental tree induction (ITI), and the other being non-incremental tree induction using a measure of tree quality instead of test quality (DMTI). These approaches and several variants offer new

Paul E. Utgoff; Neil C. Berkman; Jeffery A. Clouse

1997-01-01

59

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 Bressenden Place London SW1E 5DU Telephone: 030 3444 0000 April, 2012 ISBN: 978-1-4098-3443-4 #12;Protected, wilfully damage or wilfully destroy a tree protected by that order without the authority's permission. 2

60

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 treeâs age. A thorough sample of other measurements will then be taken to calculate the treesâ 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

61

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

62

Chem-Is-Tree  

NASA Astrophysics Data System (ADS)

Trees are woody plants that contain chemicals and undergo chemical reactions. They consist of cellulose, volatile oils, fatty acids, and more. Wood is obtained from the stems, roots, and branches of trees. It is not a homogeneous material with a uniform structure but instead a tissue of different kinds of cells which perform specific functions in the living plant. Trees are of great importance. They provide oxygen which results from photosynthesis taking place in their leaves. In addition, trees supply us with interesting products such as vanilla flavoring and natural-rubber used in cements, adhesives, vehicle tires and shoes.

Barry, Dana M.

1997-10-01

63

National Register of Big Trees  

NSDL National Science Digital Library

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

Forests, American

64

PLANTING TECHNIQUES FOR TREE SPADE DUG TREES1  

Microsoft Academic Search

New growth on Japanese black pines and Hopa flowering crabapples was greater on tree-spade-du g trees transplanted into back-hoe dug holes than on tree-spade-du g trees transplanted into holes dug and modified in other ways. This study suggests that a large volume of well-aerated backfill will reduce transplanting stress. Digging and planting landscape trees with tree spades is likely to

Robert Birdel; Carl Whitcomb; B. L. Appleton

65

Trees Are Terrific!  

ERIC Educational Resources Information Center

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

Braus, Judy, Ed.

1992-01-01

66

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.

Foundation, National S.; Learn, Nbc; Science 360 Network

67

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

68

Leonardo's Tree Theory  

NSDL National Science Digital Library

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

Werner, Suzanne K.

2003-03-01

69

Artificial Dendritic Trees  

Microsoft Academic Search

We continue our exploration of the capabilities of artificial dendritic trees by using them to construct units that signal the speed and direction of visual targets in space. By applying three different types of synaptic behavior, we demonstrate that it is relatively easy to obtain dendritic tree responses that differentiate direction of movement and encode target speed.

John G. Elias

1993-01-01

70

Thin Junction Trees  

Microsoft Academic Search

We present an algorithm that induces a class of models with thin junction trees—models that are characterized by an upper bound on the size of the maximal cliques of their triangulated graph. By ensurin g that the junction tree is thin, inference in our models remains tract able throughout the learning process. This allows both an efficient implemen tation of

Francis R. Bach; Michael I. Jordan

2001-01-01

71

Trees for Mother Earth.  

ERIC Educational Resources Information Center

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

Greer, Sandy

1993-01-01

72

PERCEPTION OF TREE CANOPY  

Microsoft Academic Search

Deciduous tree canopy was investigated in relation to perception of fecundity and visual attractiveness. Canopy having deliquescent shape was defined by season (in leaf or in branch), fullness (amount of leaf and amount of branch) and, in the case of summer trees, combinations of leaf and branch (balance of leaf to branch). Applying the Gestalt principle of closure or completeness,

THOMAS NELSON; THOMAS JOHNSON; MICHAEL STRONG; GAIL RUDAKEWICH

2001-01-01

73

Tea tree oil  

MedlinePLUS

... of the nail (onychomycosis), lice, scabies, athlete’s foot (tinea pedis), and ringworm. It is also used topically as a local ... TEA TREE OIL are as follows:Athlete’s foot (tinea pedis). Topical application of a 10% tea tree ...

74

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

75

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

76

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.

77

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

78

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

79

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

80

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.

81

The tree BVOC index.  

PubMed

Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. PMID:21435760

Simpson, J R; McPherson, E G

2011-01-01

82

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

83

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

84

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.

White, Brian

2012-06-28

85

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.

Foundation, Wgbh E.

2007-08-09

86

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

87

The Average Height of Binary Trees and Other Simple Trees  

Microsoft Academic Search

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

Philippe Flajolet; Andrew M. Odlyzko

1982-01-01

88

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

89

Handy Family Tree  

NSDL National Science Digital Library

In this bilingual (English/Spanish) activity, learners create family trees by tracing the hands of their family members. Learners list inherited traits like eye color, freckles, and chin shape on the fingers of the left hands and list learned traits like favorite foods, games, and pets on the fingers of the right hands. Learners assemble the hands to form trees. Use this family activity to help learners distinguish between inherited and learned traits.

Utah, University O.

2006-01-01

90

Peach Tree Pruning.  

E-print Network

8-1550 Texas Agricultural Extension Service -...,..-- PePEACH TREE PRUNING Texas Agricultural Extension Service. Zerle L. Carpenter, Director. The Texas A&M University System. College Station, Texas (Blank... Pa..e ln ~O~BldletinJ . -/., .~ . :~. ' .:' .; f.' ):, . ~- :: ; ',': } . .. ~ '::, PEACH TREE PRUNING Calvin G. Lyons* Peaches are pruned in several ways in the U.S. depending on the area, rainfall, grower preference and tradition...

Lyons, Calvin G.

1986-01-01

91

On Trees and Logs  

Microsoft Academic Search

In this paper we critically examine the main workhorse model in asset pricing theory, the Lucas (1978) tree model (LT-Model), extended to include heterogeneous agents and multiple goods, and contrast it to the benchmark model in financial equilibrium theory, the real assets model (RA-Model). Households in the LT-Model trade goods together with claims to Lucas trees (exogenous stochastic dividend streams

Anna Pavlova; David Cass

2002-01-01

92

ON TREES AND LOGS  

Microsoft Academic Search

In this paper we critically examine the main workhorse model in asset pricing theory, the Lucas (1978) tree model (LT-Model), extended to include heterogeneous agents and multiple goods, and contrast it to the benchmark model in financial equilibrium theory, the real assets model (RA-Model). Households in the LT-Model trade goods together with claims to Lucas trees (exogenous stochastic dividend streams

David Cass; Anna Pavlova

2003-01-01

93

Tree nut allergy  

Microsoft Academic Search

Tree nuts are clinically associated with severe immunoglobulin E-mediated systemic allergic reactions independent of pollen\\u000a allergy and with reactions that are usually confined to the oral mucosa in patients with immunoglobulin E directed toward\\u000a cross-reacting pollen allergens. The latter reactions can progress to severe and life-threatening episodes in some patients.\\u000a Many patients with severe tree nut allergy are co-sensitized to

Suzanne S. Teuber; Sarah S. Comstock; Shridhar K. Sathe; Kenneth H. Roux

2003-01-01

94

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

95

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.

Cole, Robert S.; Spreadsheets Across the Curruculum; Washington Center; Science Education Resource Center (SERC)

96

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

97

Growth stock: trees for California  

Microsoft Academic Search

Trees as a natural resource, an energy source, and a symbol of appropriate technology, are placed in the historical context of California's past treatment of its trees. The book explores the tree's function as a wood factory, its role in soil conservation and erosion control, and its nurturing aspects in providing wildlife habitat and aesthetic pleasure. It discusses trees as

1982-01-01

98

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

99

Tree domestication in tropical agroforestry  

Microsoft Academic Search

We execute tree ‘domestication’ as a farmer-driven and market-led process, which matches the intraspecific diversity of locally\\u000a important trees to the needs of subsistence farmers, product markets, and agricultural environments. We propose that the products\\u000a of such domesticated trees are called Agroforestry Tree Products (AFTPs) to distinguish them from the extractive tree resources\\u000a commonly referred to as non-timber forest products

A. J. Simons; R. R. B. Leakey

2004-01-01

100

Forest & Shade Tree Pathology  

NSDL National Science Digital Library

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

2008-02-01

101

Trees and Carbon  

NSDL National Science Digital Library

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

Pratte, John

102

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;); Linda Weinland (Edison College;); William Bromer (University of St. Francis;); K. Rebecca Thomas (Montgomery College;)

2007-06-17

103

Learning Tractable Graphical Models: Latent Trees and Tree Mixtures  

E-print Network

Learning Tractable Graphical Models: Latent Trees and Tree Mixtures Anima Anandkumar U.C. Irvine satellite science program puck scsi season pc phone question religion players power research rights shuttle

Anandkumar, Animashree

104

Global Tree Optimization: A Non-greedy Decision Tree Algorithm  

Microsoft Academic Search

A non-greedy approach for constructing globally optimalmultivariate decision trees with fixed structure is proposed.Previous greedy tree construction algorithms arelocally optimal in that they optimize some splitting criterionat each decision node, typically one node at a time.In contrast, global tree optimization explicitly considersall decisions in the tree concurrently. An iterative linearprogramming algorithm is used to minimize the classificationerror of the entire

Kristin P. Bennett

1994-01-01

105

Recursive queries on trees and data trees Serge Abiteboul  

E-print Network

that the three aforementioned problems are unde- cidable for data trees. But in practice, data trees (e.g., XML that for bounded depth data trees, one can solve This work has been partially funded by the European Re- search No. 61100062 by the Engineering and Physical Sciences Re- search Council project "Query-Driven Data

Paris-Sud XI, Université de

106

Tree Fertilization Soil Analysis  

E-print Network

Tree Fertilization #12;Soil Analysis vs. Foliar Analysis #12;Macronutrients N P K Mg S Ca N/ "DBH Timing ­ water availability -- spring and fall #12;Application Techniques Surface broadcast ·Least time ·Simple equipment ·Water thoroughly ·Grass is competition #12;#12;#12;Drill Hole Method

107

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

108

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

109

The Medicine Tree.  

ERIC Educational Resources Information Center

Demographic changes in population continue to bring children of different cultural backgrounds to classrooms. This article provides suggestions teachers and counselors can use to bridge cultures. Using the parable of a medicine tree, it explains how no society can endure without caring for its young. (Author/JDM)

Brokenleg, Martin

2000-01-01

110

Learning in Boltzmann Trees  

Microsoft Academic Search

We introduce a large family of Boltzmann machines that can be trainedusing standard gradient descent. The networks can have one or morelayers of hidden units, with tree-like connectivity. We show how to implementthe supervised learning algorithm for these Boltzmann machinesexactly, without resort to simulated or mean-field annealing. The stochasticaverages that yield the gradients in weight space are computed by thetechnique

Lawrence K. Saul; Michael I. Jordan

1994-01-01

111

Hidden Markov Decision Trees  

Microsoft Academic Search

Abstract: We study a time series model that can be viewed as a decisiontree with Markov temporal structure. The model is intractable forexact calculations, thus we utilize variational approximations. Weconsider three different distributions for the approximation: one inwhich the Markov calculations are performed exactly and the layersof the decision tree are decoupled, one in which the decision treecalculations are performed

Michael I. Jordan; Zoubin Ghahramani; Lawrence K. Saul

1996-01-01

112

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

113

Fuzzy fault tree analysis  

Microsoft Academic Search

Reliability of products is frequently a prime safety consideration. Interpretation of reliability is both quantitative and qualitative. Extensive quantitative analysis employing probablistic risk assessment has been widely performed to provide predicted hazard or accident minimization. Weibull probability data and information is a vital tool of these quantitative risk assessments, but so are qualitative methods such as fault tree analysis. Qualitative

David P. Weber

1994-01-01

114

Palm Tree Peroxidases  

Microsoft Academic Search

Over the years novel plant peroxidases have been isolated from palm trees leaves. Some molecular and catalytic properties of palm peroxidases have been studied. The substrate specificity of palm peroxidases is distinct from the specificity of other plant peroxidases. Palm peroxidases show extremely high stability under acidic and alkaline conditions and high thermal stability. Moreover, these enzymes are more stable

I. Yu. Sakharov

2004-01-01

115

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.

116

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.

117

Giant Sequoia Tree  

NSDL National Science Digital Library

The purpose of this assessment probe is to elicit students' ideas about transformation of matter. The probe is designed to reveal whether students recognize that a gas from the air (carbon dioxide) is combined with water and transformed into the new material that makes up most of the matter of the tree.

Eberle, Francis; Tugel, Joyce; Keeley, Page

2007-01-01

118

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

119

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).

120

An Introduction to Tree Diagrams  

NSDL National Science Digital Library

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

Cork, Stu

2014-01-01

121

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!

Walsh, Mary

122

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....

2010-05-03

123

Tree of Life Workshop Report  

NSF Publications Database

... Evolution of Development meets Tree Of Life What are the most exciting questions in the Evolution of ... Singer Evolution of Development meets Tree of Life What happens when the Evolution of Developmental ...

124

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

125

Learning with Mixtures of Trees  

Microsoft Academic Search

This paper describes the mixtures-of-trees model, a probabilistic model for discrete multidimensional domains. Mixtures-of-trees generalize the probabilistic trees of Chow and Liu (6) in a different and complementary direction to that of Bayesian networks. We present efficient algorithms for learning mixtures-of-trees models in maximum likelihood and Bayesian frameworks. We also discuss additional efficiencies that can be obtained when data are

Marina Meila; Michael I. Jordan

2000-01-01

126

Street Trees and Intersection Safety  

Microsoft Academic Search

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

Elizabeth Macdonald; Alethea Harper; Jason A. Hayter

2006-01-01

127

Rate of tree carbon accumulation increases continuously with tree size  

USGS Publications Warehouse

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

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

2014-01-01

128

Climate change & street trees project  

E-print Network

to obtain appropriate knowledge contributes strongly to this loss. 4. Street trees can posses a range to this and is significantly divided. 6. The governance promoting the removal of street trees is very strong, resting upon knowledge, and thus make `informed' decisions, relating to trees and their m

129

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

130

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

131

Failure Diagnosis Using Decision Trees  

Microsoft Academic Search

We present a decision tree learning approach to diagnos- ing failures in large Internet sites. We record runtime prop- erties of each request and apply automated machine learn- ing and data mining techniques to identify the causes of failures. We train decision trees on the request traces from time periods in which user-visible failures are present. Paths through the tree

Mike Y. Chen; Alice X. Zheng; Jim Lloyd; Michael I. Jordan; Eric A. Brewer

2004-01-01

132

Genetic conservation of native trees  

E-print Network

, 2001). Chloroplast DNA investigations have continued and include work on veteran oak treesGenetic 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

133

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.

134

Multivariate versus Univariate Decision Trees  

Microsoft Academic Search

In this paper we present a new multivariate decision tree algorithm LMDT,which combines linear machines with decision trees. LMDT constructs eachtest in a decision tree by training a linear machine and then eliminating irrelevantand noisy variables in a controlled manner. To examine LMDT's abilityto find good generalizations we present results for a variety of domains. Wecompare LMDT empirically to a

Carla E. Brodley; Paul E. Utgoff

1992-01-01

135

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

136

Selecting Landscape Plants: Shade Trees  

E-print Network

Selecting Landscape Plants: Shade Trees Diane Relf, Extension Specialist, Horticulture, Virginia-295, Guidelines for Planting Landscape Trees. Tree species described in the following sections are the ones most because they are commonly available, even though they are not recommended for general landscape planting

Liskiewicz, Maciej

137

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

138

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

139

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

140

Red-black Tree Jingjing Xia  

E-print Network

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

Chen, Yangjun

141

Fault-Tree Compiler Program  

NASA Technical Reports Server (NTRS)

FTC, Fault-Tree Compiler program, is reliability-analysis software tool used to calculate probability of top event of fault tree. Five different types of gates allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language of FTC easy to understand and use. Program supports hierarchical fault-tree-definition feature simplifying process of description of tree and reduces execution time. Solution technique implemented in FORTRAN, and user interface in Pascal. Written to run on DEC VAX computer operating under VMS operating system.

Butler, Ricky W.; Martensen, Anna L.

1992-01-01

142

Global Value Trees  

E-print Network

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

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

2014-01-01

143

On trees and logs  

Microsoft Academic Search

In this paper we contrast the main workhorse model in asset pricing theory, the Lucas (1978) tree model (LT-Model), to a benchmark model in financial equilibrium theory, the real assets model (RA-Model). It is commonly believed that the two models entail similar conclusions since the LT-Model is a special case of the RA-Model. But this is simply wrong: implications of

David Cass; Anna Pavlova

2004-01-01

144

Counting Spanning Trees Diplomarbeit  

E-print Network

. Operations on Graphs 13 Chapter 3. Equivalent Objects 19 1. Duality 19 2. Chip­Firing Games on Graphs 20 3 34 2. Dividing Graphs 39 3. Codes 41 Chapter 5. Algebraic Proofs 53 1. The Matrix­Tree­Theorem 53 2 a subset S of a set S we will write S c for the complement of S in S. The entry in row i and column j

Krattenthaler, Christian

145

TreeFix: Statistically Informed Gene Tree Error Correction Using Species Trees  

PubMed Central

Accurate gene tree reconstruction is a fundamental problem in phylogenetics, with many important applications. However, sequence data alone often lack enough information to confidently support one gene tree topology over many competing alternatives. Here, we present a novel framework for combining sequence data and species tree information, and we describe an implementation of this framework in TreeFix, a new phylogenetic program for improving gene tree reconstructions. Given a gene tree (preferably computed using a maximum-likelihood phylogenetic program), TreeFix finds a “statistically equivalent” gene tree that minimizes a species tree-based cost function. We have applied TreeFix to 2 clades of 12 Drosophila and 16 fungal genomes, as well as to simulated phylogenies and show that it dramatically improves reconstructions compared with current state-of-the-art programs. Given its accuracy, speed, and simplicity, TreeFix should be applicable to a wide range of analyses and have many important implications for future investigations of gene evolution. The source code and a sample data set are available at http://compbio.mit.edu/treefix. PMID:22949484

Wu, Yi-Chieh; Rasmussen, Matthew D.; Bansal, Mukul S.; Kellis, Manolis

2013-01-01

146

CST-Trees: Cache Sensitive T-Trees  

Microsoft Academic Search

Abstract. Researchers have modified ,existing index structures into ones opti- mized for CPU cache performance,in main,memory,database environments. A Cache Sensitive B+-Tree is one of them. It is designed to minimize,the impact ofcache,misses for B+-Trees and it has been known,to be more effective than other types of main memory index structure including T-Trees. In this paper, we introduce a Cache Sensitive

Ig-hoon Lee; Junho Shim; Sang-goo Lee; Jonghoon Chun

2007-01-01

147

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

148

Diameter-Constrained Steiner Tree  

NASA Astrophysics Data System (ADS)

Given an edge-weighted undirected graph G = (V,E,c,w), where each edge e ? E has a cost c(e) and a weight w(e), a set S ? V of terminals and a positive constant D 0, we seek a minimum cost Steiner tree where all terminals appear as leaves and its diameter is bounded by D 0. Note that the diameter of a tree represents the maximum weight of path connecting two different leaves in the tree. Such problem is called the minimum cost diameter-constrained Steiner tree problem. This problem is NP-hard even when the topology of Steiner tree is fixed. In present paper we focus on this restricted version and present a fully polynomial time approximation scheme (FPTAS) for computing a minimum cost diameter-constrained Steiner tree under a fixed topology.

Ding, Wei; Lin, Guohui; Xue, Guoliang

149

Dimers, Tilings and Trees  

E-print Network

Generalizing results of Temperley, Brooks, Smith, Stone and Tutte and others we describe a natural equivalence between three planar objects: weighted bipartite planar graphs; planar Markov chains; and tilings with convex polygons. This equivalence provides a measure-preserving bijection between dimer coverings of a weighted bipartite planar graph and spanning trees on the corresponding Markov chain. The tilings correspond to harmonic functions on the Markov chain and to ``discrete analytic functions'' on the bipartite graph. The equivalence is extended to infinite periodic graphs, and we classify the resulting ``almost periodic'' tilings and harmonic functions.

Richard Kenyon; Scott Sheffield

2003-10-13

150

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.

Bell, Tim; Witten, Ian; Fellows, Mike

1998-01-01

151

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.

152

Fires on trees  

E-print Network

We consider random dynamics on the edges of a uniform Cayley tree with $n$ vertices, in which edges are either inflammable, fireproof, or burt. Every inflammable edge is replaced by a fireproof edge at unit rate, while fires start at smaller rate $n^{-\\alpha}$ on each inflammable edge, then propagate through the neighboring inflammable edges and are only stopped at fireproof edges. A vertex is called fireproof when all its adjacent edges are fireproof. We show that as $n\\to \\infty$, the density of fireproof vertices converges to 1 when $\\alpha>1/2$, to 0 when $\\alphafireproof forest, in particular the existence of a giant component.

Bertoin, Jean

2010-01-01

153

Redrawing Humanity's Family Tree  

NSDL National Science Digital Library

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

Wilford, John N.

1969-12-31

154

A Tree of Genetic Traits  

NSDL National Science Digital Library

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

Malone, Molly; Starr, Harmony; Mitchell, April

2006-01-01

155

Barking up the Right Tree  

ERIC Educational Resources Information Center

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

Houston, Paul D.

2006-01-01

156

Compositional Temporal Fault Tree Analysis  

Microsoft Academic Search

HiP-HOPS (Hierarchically-Performed Hazard Origin and Propaga- tion Studies) is a recent technique that partly automates Fault Tree Analysis (FTA) by constructing fault trees from system topologies annotated with component-level failure specifications. HiP-HOPS has hitherto created only classical combinatorial fault trees that fail to capture the often significant temporal ordering of failure events. In this paper, we propose temporal extensions to

Martin Walker; Leonardo Bottaci; Yiannis Papadopoulos

2007-01-01

157

Incremental Induction of Decision Trees  

Microsoft Academic Search

This article presents an incremental algorithm for inducing decision trees equivalent to those formed by Quinlan's nonincremental ID3 algorithm, given the same training instances. The new algorithm, named ID5R, lets one apply the ID3 induction process to learning tasks in which training instances are presented serially. Although the basic tree-building algorithms differ only in how the decision trees are constructed,

Paul E. Utgoff; Pat Langley

1989-01-01

158

Genetically optimized fuzzy decision trees  

Microsoft Academic Search

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

Witold Pedrycz; Zenon A. Sosnowski

2005-01-01

159

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

160

Relating phylogenetic trees to transmission trees of infectious disease outbreaks.  

PubMed

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

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

2013-11-01

161

CartograTree: connecting tree genomes, phenotypes and environment.  

PubMed

Today, researchers spend a tremendous amount of time gathering, formatting, filtering and visualizing data collected from disparate sources. Under the umbrella of forest tree biology, we seek to provide a platform and leverage modern technologies to connect biotic and abiotic data. Our goal is to provide an integrated web-based workspace that connects environmental, genomic and phenotypic data via geo-referenced coordinates. Here, we connect the genomic query web-based workspace, DiversiTree and a novel geographical interface called CartograTree to data housed on the TreeGenes database. To accomplish this goal, we implemented Simple Semantic Web Architecture and Protocol to enable the primary genomics database, TreeGenes, to communicate with semantic web services regardless of platform or back-end technologies. The novelty of CartograTree lies in the interactive workspace that allows for geographical visualization and engagement of high performance computing (HPC) resources. The application provides a unique tool set to facilitate research on the ecology, physiology and evolution of forest tree species. CartograTree can be accessed at: http://dendrome.ucdavis.edu/cartogratree. PMID:23433187

Vasquez-Gross, Hans A; Yu, John J; Figueroa, Ben; Gessler, Damian D G; Neale, David B; Wegrzyn, Jill L

2013-05-01

162

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

163

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

164

Integrality ratio for Group Steiner Trees and Directed Steiner Trees  

Microsoft Academic Search

We present an (log 2 k) lower bound on the integrality ratio of the o w-based relaxation for the Group Steiner Tree problem, where k denotes the number of groups; this holds even for input graphs that are Hierarchically Well- Separated Trees, introduced by Bartal (Symp. Foundations of Computer Science, pp. 184{193, 1996), in which case this lower bound is

Eran Halperin; Guy Kortsarz; Robert Krauthgamer; Aravind Srinivasan; Nan Wang

165

Supporting Medical Decisions with Vector Decision Trees  

Microsoft Academic Search

The article presents the extension of a common decision tree concept to a multidimensional - vector - decision tree constructed with the help of evolutionary techniques. In contrary to the common decision tree the vector decision tree can make more than just one suggestion per input sample. It has the functionality of many separate decision trees acting on a same

Peter Kokol; Norihiro Sakamoto

166

Water transport in trees—an artificial laboratory tree  

NASA Astrophysics Data System (ADS)

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 construction of an artificial tree is an ideal laboratory project, which enables detailed studies of several phenomena related to water transport in an artificial tree model; it also clearly shows the failures of widespread ideas about the origins of the upward water flow. We present the construction of the laboratory tree, suggest measurements that illustrate water transport and present a few additional experiments which clearly show why water transport in trees higher than 10 m is still an ongoing debate amongst plant physiologists.

Susman, K.; Razpet, N.; ?epi?, M.

2011-05-01

167

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

168

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

E-print Network

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

Alechina, Natasha

169

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

170

Competitive learning in decision trees  

NASA Astrophysics Data System (ADS)

In this paper, a competitive learning rule is introduced in decision trees as a computationally attractive scheme for adaptive density estimation or lossy compression. It is shown by simulation that the adaptive decision tree performs at least as well as other competitive learning algorithms while being much faster.

Martinez, Dominique

1998-07-01

171

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

172

Beta Diffusion Trees Creighton Heaukulani  

E-print Network

- clustered factor analysis model with the beta dif- fusion tree and how to perform inference over the random subsets of objects, known as a feature allocation. The generative process for the tree is defined in terms of particles (representing the objects) diffusing in some continuous space, analogously to the Dirichlet

Edinburgh, University of

173

Information Processing in Dendritic Trees  

Microsoft Academic Search

This review considers the input-output behavior of neurons with dendritic trees, with an emphasis on questions of information processing. The parts of this review are (1) a brief history of ideas about dendritic trees, (2) a review of the complex electrophysiology of dendritic neurons, (3) an overview of conceptual tools used in dendritic modeling studies, including the cable equation and

Bartlett W. Mel

1994-01-01

174

TREE FAILURES AND ACCIDENTS IN  

E-print Network

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

Standiford, Richard B.

175

AFTP Fault Tree Analysis Program  

Microsoft Academic Search

Evaluation of the cut sets of large s-coherent and non-coherent fault trees presents a severe computational problem. The computer program, AFTP has been used to evaluate the important minimal cut and path sets of large fault trees containing many hundreds of gates. The computational advantages of a Boolean algebra, bottom-up approach are emphasised.

Richard A. Pullen

1984-01-01

176

Uncertainties in Fault Tree Analysis  

Microsoft Academic Search

Fault tree analysis is one kind of the probabilistic safety analysis method. After constructing a fault tree, many basic events which can happen theoretically have never occurred so far or have occurred so infrequently that their reasonable data are not available. However, the use of fuzzy probability can describe the failure probability and its uncertainty of each basic event ,

Yue-Lung Cheng

177

Genome Trees from Conservation Profiles  

PubMed Central

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

Tekaia, Fredj; Yeramian, Edouard

2005-01-01

178

Packing Steiner trees Microsoft Research  

E-print Network

@cs.toronto.edu Abstract The Steiner packing problem is to #12;nd the maximum number of edge-disjoint subgraphs of a given Steiner tree problem via the ellipsoid algorithm. 1 Introduction In the Steiner tree packing problem practical as well as theoretical considerations. The problem in its full generality (where for each Steiner

Salavatipour, Mohammad R.

179

Elemental composition of tree nuts  

Microsoft Academic Search

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

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

1979-01-01

180

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

181

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.

182

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

183

Definition Synaptic Integration in Dendritic Trees  

E-print Network

#12; Definition Synaptic Integration in Dendritic Trees Propagation of Action Potentials possible function of dendritic trees is to spatially isolate synaptic inputs to enhance their summation synaptic responses as they propagate through the dendritic tree. Synaptic events are conductance changes

Alford, Simon

184

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

185

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

186

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

187

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

188

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

E-print Network

in NH and found mostly in the southern part of the state. Look for this medium sized often shrubby tree that grows naturally New England. Our Mountain laurel, kalmia latifolia, is a member of the heath family. Years ago I noticed the bright red and blue tropical looking fruit on some of our trees. The unusual

New Hampshire, University of

189

Tree SelectionTree Selection Why is selection important?  

E-print Network

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

190

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.

Gogeshvili, Arsen

191

Urban Tree Planting: Soil 101  

NSDL National Science Digital Library

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

Planet, Pulse O.

2007-11-28

192

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

193

Integrality ratio for group Steiner trees and directed steiner trees  

Microsoft Academic Search

We present an ?(log2k) lower bound on the integrality ratio of the flow-based relaxation for the Group Steiner Tree problem, where k denotes the number of groups; this holds even for input graphs that are Hierarchically Well-Separated Trees, introduced by Bartal [Symp. Foundations of Computer Science, pp. 184--193, 1996], in which case this lower bound is tight. This relaxation appears

Eran Halperin; Guy Kortsarz; Robert Krauthgamer; Aravind Srinivasan; Nan Wang

2003-01-01

194

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

E-print Network

ICE RESISTANT TREE POPULATIONS Adapted from: TREES AND ICE STORMS: THE DEVELOPMENT OF ICE STORM. University of Illinois Tree Features Influencing Ice Storm Susceptibility A number of characteristics increase a tree species' susceptibility to ice storms: "included" bark, decaying or dead branches

New Hampshire, University of

195

Summing tree graphs at threshold  

NASA Astrophysics Data System (ADS)

The solution of the classical field equation generates the sum of all tree graphs. We show that the classical equation reduces to an easily solved ordinary differential equation for certain multiparticle threshold amplitudes and compute these amplitudes.

Brown, Lowell S.

1992-11-01

196

Learning Latent Tree Graphical Models  

E-print Network

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

Choi, Myung Jin

197

Millersville University's Trees of Distinction  

E-print Network

-06-03 #12;#12: Eastern hemlock (Tsuga canadensis) 2014-04-24 #12;#13: Kentucky coffee tree (Gymnocladus dioica) #12;#14: Flowering dogwood (Cornus florida) 2014-05-22 #12;#15: London plane, Hybrid sycamore

Hardy, Christopher R.

198

Cultural Values of Trees, Woods  

E-print Network

Tabbush #12;ocultural benefit and benefits provided by trees woodlands and forests were considered. Cultural values are taken into account the nature of the woodland and our cultural relationship with it. The physical nature of woodlands

199

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

Takacs, L

1992-01-01

200

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

201

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

202

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

203

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

204

Tree-structured approximations by expectation propagation  

E-print Network

implemented in Matlab using Bayes Net Toolbox · Floating-point operations (FLOPS) counted via Lightspeed toolbox · 5% rule: stop when error on all following iterations is within 5% of final error #12;Other algorithms · TreeVB (Wiegerinck, 2000) with same tree structure as TreeEP, same junction tree optimizations

Minka,Tom

205

Water in the trunk of a tree  

NSDL National Science Digital Library

Every December, people cut down pine trees and other evergreens and stick them in their houses. The trees start sucking up water right away (unless you wait too long between cutting the tree and putting it in water, of course). A new study helps to explain how the heck water moves up the trunk of cone-making trees called "conifers."

American Association for the Advancement of Science (AAAS;)

2005-12-22

206

A Tool for Displaying Syntactic Trees.  

ERIC Educational Resources Information Center

A computer program for drawing syntactic phrase markers as trees is described. The program was developed for use on Texas Instruments Explorer Lisp machines. The tree is drawn by recursive descent, left to right. The tree-drawing function takes two arguments: (1) an atom constituting the tree, and (2) a font specification to be used in drawing the…

Morgan, Jerry L.

207

A Compendium on Steiner Tree Problems  

E-print Network

A Compendium on Steiner Tree Problems Editors: M. Hauptmann and M. Karpinski Department of Computer compendium on approximability of the Steiner Tree and related optimization problems. Address for correspondence: steinercompendium@cs.uni-bonn.de. 1 #12;Chapter 1 Steiner Tree Problems 1.1 Minimum Steiner Tree

Behnke, Sven

208

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

209

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.

210

Parallel TreeSPH  

NASA Astrophysics Data System (ADS)

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

Davé, Romeel; Dubinski, John; Hernquist, Lars

1997-08-01

211

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

212

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

213

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

214

BlobTree Trees Callum Galbraith Peter MacMurchy Brian Wyvill  

E-print Network

;Figure 2. Photograph of an arbutus tree show- ing smooth junctions between branches. poratedBlobTree Trees Callum Galbraith Peter MacMurchy Brian Wyvill Department of Computer Science for modeling botanical trees have been proposed. The geometry and topology of tree skeletons can be well

Wyvill, Brian

215

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

216

Trace Gold Reveals Tree?s Past (PR 05-099)  

NSF Publications Database

... Trace Gold Reveals Tree's Past A sample has been removed from this tree slice to examine it for ... Using a new method to detect trace elements in tree rings, researchers at Cornell University and ...

217

Red-black Trees To know what a red-black tree is (10.1).  

E-print Network

809 CHAPTER 10 Red-black Trees Objectives · To know what a red-black tree is (§10.1). · To convert a red-black tree to a 2-4 tree and vice versa (§10.2). · To design the RBTree class that extends the BinaryTree class (§10.3). · To insert an element in a red-black tree and resolve the double red problem

Liang, Y. Daniel

218

Detection of individual trees and estimation of tree height using LiDAR data  

Microsoft Academic Search

For estimation of tree parameters at the single-tree level using light detection and ranging (LiDAR), detection and delineation\\u000a of individual trees is an important starting point. This paper presents an approach for delineating individual trees and estimating\\u000a tree heights using LiDAR in coniferous (Pinus koraiensis, Larix leptolepis) and deciduous (Quercus spp.) forests in South Korea. To detect tree tops, the

Doo-Ahn Kwak; Woo-Kyun Lee; Jun-Hak Lee; Greg S. Biging; Peng Gong

2007-01-01

219

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

220

Attention trees and semantic paths  

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

221

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

E-print Network

Roundheaded apple-tree borer larva #12;control apple maggot, leafminers, and other pests. Backyard treesBorers in New Hampshire Apple Trees Several species of insects bore into New Hampshire apple trees, including roundheaded apple tree borer, flatheaded apple-tree borer, dogwood borer (and the uncommon look

New Hampshire, University of

222

Simplicial matrix-tree theorems  

E-print Network

F is the facet of ? corresponding to that column. Let ˆ? k be the product of the nonzero eigenvalues of ˆ L ud ?,k?1 ,andlet ˆ? k =ˆ? k (?) = summationdisplay ??T k (?) | ˜ H k?1 (?)| 2 X ? . Theorem 1.4 (Weighted Simplicial Matrix-Tree Theorem). Let ? be a d... are explained in more detail in Section 8.4. Its spanning trees are enumerated in Examples 9.1 (fine weighting) and 9.3 (coarse weighting). We prove Theorem 1.5 by exploiting the recursive structure of shifted complexes. As in [13], we begin by calculating...

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

2009-01-01

223

Interpreting the universal phylogenetic tree  

NASA Technical Reports Server (NTRS)

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

Woese, C. R.

2000-01-01

224

Multiple Tree for Partially Observable Monte-Carlo Tree Search  

E-print Network

We propose an algorithm for computing approximate Nash equilibria of partially observable games using Monte-Carlo tree search based on recent bandit methods. We obtain experimental results for the game of phantom tic-tac-toe, showing that strong strategies can be efficiently computed by our algorithm.

Auger, David

2011-01-01

225

Tree Height Calculator: An Android App for Estimating Tree Height  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

226

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

227

Boron translocation in coffee trees  

Microsoft Academic Search

Boron deficiency in coffee trees (Coffea arabica) is widespread, however, responses to B fertilizer have been erratic, depending on the year, method, and time of application. A better understanding of B uptake, distribution, and remobilization within the plant is important in developing a rational fertilization program. Field\\u000a and greenhouse experiments were conducted to study B distribution and remobilization in coffee

Vagner M. Leite; Patrick H. Brown; Ciro A. Rosolem

2007-01-01

228

SHADE TREE LEAF SCORCH1  

Microsoft Academic Search

The term scorch is commonly used to describe foliar symptoms of marginal and interveinal dessication. A diversity of abiotic and biotic agents cause scorch symptoms in shade trees. Thus there are many physiologic and pathologic bases for leaf scorch. Little research has been performed to define these bases; however, recent research involving fastidious xylem-inhabiting bacteria (FXIB) in elm, sycamore, oak,

R. Hammerschlag; J. Sherald; S. Kostka

1983-01-01

229

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

230

General Fragmentation Trees Robin Stephenson  

E-print Network

of any self-similar fragmentation process can be encoded in a compact measured R-tree. Under some shaved off and thrown away, and actual splittings of fragments which are governed by a Poisson point, si 1}. Precise definitions can be found in the main body of the article. Our main inspiration

Paris-Sud XI, Université de

231

Tree coding of image subbands.  

PubMed

The authors consider the encoding of image subbands with a tree code that is asymptotically optimal for Gaussian sources and the mean squared error (MSE) distortion measure. They first prove that optimal encoding of ideally filtered subbands of a Gaussian image source achieves the rate distortion bound for the MSE distortion measure. The optimal rate and distortion allocation among the subbands is a by-product of this proof. A bound is derived which shows that subband coding is closer than full-band coding to the rate distortion bound for a finite length sequence. The tree codes are then applied to encode the image subbands, both nonadaptively and adaptively. Since the tree codes are stochastic and the search of the code tree is selective, a relatively few reproduction symbols may have an associated squared error a hundred times larger than the target for the subband. Correcting these symbols through a postcoding procedure improves the signal-to-noise ratio and visual quality significantly, with a marginal increase in total rate. PMID:18296149

Nanda, S; Pearlman, W A

1992-01-01

232

Supervised Harvesting of Expression Trees  

Microsoft Academic Search

BackgroundWe propose a new method for supervising learning from gene expressiondata. We call it \\\\Tree Harvesting". This technique startswith a hierarchical clustering of genes, and models the outcome variableas a sum of the average expression proles of chosen clusters, andtheir products. It can be applied to many dierent kinds of outcomemeasures, such as censored survival times, or a response falling

Trevor Hastie; Robert Tibshirani; David Botstein; Patrick Brown

2000-01-01

233

Supervised harvesting of expression trees  

Microsoft Academic Search

BACKGROUND: We propose a new method for supervised learning from gene expression data. We call it 'tree harvesting'. This technique starts with a hierarchical clustering of genes, then models the outcome variable as a sum of the average expression profiles of chosen clusters and their products. It can be applied to many different kinds of outcome measures such as censored

Trevor Hastie; Robert Tibshirani; David Botstein; Patrick Brown

2001-01-01

234

Tree pits as urban gardens  

Microsoft Academic Search

The planting containers and tree pits in many parts of New York have been decorated by residents and their agents, using plants, paints, rock and other materials. Such decoration is examined and variations linked to socio?economic groups in different types of dwellings. Some possible motivations are suggested.

Steven Strom

1990-01-01

235

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

236

Human Arterial-Tree Multiscale  

E-print Network

spatial scales Human arterial-tree multiscale simulations The human vascular system is incredibly complex with Overlapping Patches for Ultrascale Simulations: Application to Biological Flows, J. Comput. Phys. (2010) D. A;Multiscale simulations with NektarG and LAMMPS � Computational domain is decomposed into three overlapping

237

(Nitrogen deposition to forest trees)  

Microsoft Academic Search

The travelers participated in two major international conferences focusing on the interaction between the atmosphere and vegetation in terrestrial ecosystems. The first addressed the issue of forest decline, whereas the second focused on controlled-environment methodologies for characterizing the influence of physical and chemical changes in the atmosphere on crops and forest trees. Both travelers presented posters at the first meeting

G. E. Jr. Taylor; P. J. Hanson

1989-01-01

238

Synaptic integration in dendritic trees  

Microsoft Academic Search

Most neurons have elaborate dendritic trees that receive tens of thousands of synaptic inputs. Because postsynaptic responses to individual synaptic events are usually small and transient, the integration of many synaptic responses is needed to depolarize most neurons to action potential threshold. Over the past decade, advances in electrical and optical recording techniques have led to new insights into how

Allan T. Gulledge; Björn M. Kampa; Greg J. Stuart

2005-01-01

239

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

240

Tree topologies in ATM networks  

Microsoft Academic Search

A detailed analysis of tree topologies in ATM networks is developed, by using a general model which takes into account also the problem of node coupling. The performance of the networks is evaluated, in terms of transfer delay and cell loss probability, in many different situations, so proving the flexibility and effectiveness of the proposed method

Andrea Borella; Giovanni Cancellieri; F. Chiaraluce; F. Meschini

1992-01-01

241

Fires on trees Jean Bertoin  

E-print Network

tree with n vertices, in which edges are either inflammable, fireproof, or burnt. Every inflammable edge is replaced by a fireproof edge at unit rate, while fires start at smaller rate n- on each inflammable edge, then propagate through the neighboring inflammable edges and are only stopped at fireproof

Paris-Sud XI, Université de

242

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

243

Limit of random walks of random trees  

E-print Network

Limit of random walks and of random trees ------------------------------ Elements phenomenons (quantum physics, magnetism, polymer, DNA, genealogical tree, random walk, Markov chain, etc, statistical physics, biology, a lot of objects hav­ ing a discrete nature appear for various reason

Marckert, Jean-François

244

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

Erdos, P.L.; Johnson, V.; Moulton, V.

2012-01-01

245

Propagating Belief Functions in AND-Trees  

E-print Network

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

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

1995-01-01

246

SOLVING STEINER TREE PROBLEMS IN GRAPHS WITH ...  

E-print Network

minals, a Steiner tree for T in G is a tree that spans T. Let c ... relaxation and polyhedral methods [32]; neural networks [38]; meta-heuristics (genetic ..... only produces dual variables, branching decisions are based on this dual information.

247

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.

248

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.

249

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

250

Wavelet tree quantization for copyright protection watermarking  

Microsoft Academic Search

This paper proposes a wavelet-tree-based blind watermarking scheme for copyright protection. The wavelet coefficients of the host image are grouped into so-called super trees. The watermark is embedded by quantizing super trees. The trees are so quantized that they exhibit a large enough statistical difference, which will later be used for watermark extraction. Each watermark bit is embedded in perceptually

Shih-hao Wang; Yuan-pei Lin

2004-01-01

251

A complete fuzzy decision tree technique  

Microsoft Academic Search

In this paper, a new method of fuzzy decision trees called soft decision trees (SDT) is presented. This method combines tree growing and pruning, to determine the structure ofthe sof t decision tree, with re4tting and back4tting, to improve its generalization capabilities. The method is explained and motivated and its behavior is 4rst analyzed empirically on 3 large databases in

Cristina Olaru; Louis Wehenkel

2003-01-01

252

Methane Emissions from Deciduous Trees  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

253

TreeDyn: towards dynamic graphics and annotations for analyses of trees  

PubMed Central

Background Analyses of biomolecules for biodiversity, phylogeny or structure/function studies often use graphical tree representations. Many powerful tree editors are now available, but existing tree visualization tools make little use of meta-information related to the entities under study such as taxonomic descriptions or gene functions that can hardly be encoded within the tree itself (if using popular tree formats). Consequently, a tedious manual analysis and post-processing of the tree graphics are required if one needs to use external information for displaying or investigating trees. Results We have developed TreeDyn, a tool using annotations and dynamic graphical methods for editing and analyzing multiple trees. The main features of TreeDyn are 1) the management of multiple windows and multiple trees per window, 2) the export of graphics to several standard file formats with or without HTML encapsulation and a new format called TGF, which enables saving and restoring graphical analysis, 3) the projection of texts or symbols facing leaf labels or linked to nodes, through manual pasting or by using annotation files, 4) the highlight of graphical elements after querying leaf labels (or annotations) or by selection of graphical elements and information extraction, 5) the highlight of targeted trees according to a source tree browsed by the user, 6) powerful scripts for automating repetitive graphical tasks, 7) a command line interpreter enabling the use of TreeDyn through CGI scripts for online building of trees, 8) the inclusion of a library of packages dedicated to specific research fields involving trees. Conclusion TreeDyn is a tree visualization and annotation tool which includes tools for tree manipulation and annotation and uses meta-information through dynamic graphical operators or scripting to help analyses and annotations of single trees or tree collections. PMID:17032440

Chevenet, Francois; Brun, Christine; Banuls, Anne-Laure; Jacq, Bernard; Christen, Richard

2006-01-01

254

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

255

Tree architecture and life-history strategies across 200 co-occurring tropical tree species  

Microsoft Academic Search

1.?Tree architecture is thought to allow species to partition horizontal and vertical light gradients in the forest canopy. Tree architecture is closely related to light capture, carbon gain and the efficiency with which trees reach the canopy. Previous studies that investigated how light gradients drive differentiation in tree architecture have produced inconsistent results, partially because of the differences in which

Y. Iida; T. S. Kohyama; T. Kubo; A. R. Kassim; L. Poorter; F. J. Sterck; M. D. Potts

2011-01-01

256

Crude sap ascent and tree recovery 1 The watering of trees. Embolization and  

E-print Network

along their vascular system. The crude sap - mainly liquid water absorbed and transported through trees, trees operate a second vascular system - phloem sieve tubes - for the circulation of metabolites thoughCrude sap ascent and tree recovery 1 The watering of trees. Embolization and recovery in xylem

Boyer, Edmond

257

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

258

Reconstruction of Tree and Latent Tree Models: Consistency and Error Rates  

E-print Network

Reconstruction of Tree and Latent Tree Models: Consistency and Error Rates Anima Anandkumar Electrical Engineering and Computer Science MIT, Cambridge, MA 02139 Joint work with Myung Jin Choi, Vincent Tan, Lang Tong and Alan Willsky. Yale University Anima Anandkumar (MIT) Trees & Latent Trees 04

Anandkumar, Animashree

259

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

E-print Network

High-Dimensional Structure Learning of Graphical Models: Trees, Latent Trees & Beyond Anima Anandkumar Electrical Engineering and Computer Science U.C. Irvine Joint work with Myung Jin Choi, Vincent Tan, and Alan Willsky. UIUC Seminar Anima Anandkumar (UCI) Trees, Latent Trees & Beyond 11/08/2010 1

Anandkumar, Animashree

260

Assessing the potential for urban trees to facilitate forest tree migration in the eastern United States  

Microsoft Academic Search

Latitudinal shifts in tree species distributions are a potential impact of climate change on forest ecosystems. It has been hypothesized that some tree species may become extirpated as climate change effects may exceed their migration ability. The goal of this study was to compare tree species compositions in northern urban areas to tree compositions in forestland areas in the eastern

C. W. Woodall; D. J. Nowak; G. C. Liknes; J. A. Westfall

2010-01-01

261

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

262

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

263

Integrality ratio for Group Steiner Trees and Directed Steiner Trees Eran Halperin  

E-print Network

Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a flow. For the Group Steiner Tree problem, we show the integrality ratio is (log2 k), where k denotes the number is tight. This also applies for the Directed Steiner Tree problem. In terms of the number n of vertices

Krauthgamer, Robert

264

Integrality ratio for Group Steiner Trees and Directed Steiner Trees Eran Halperin  

E-print Network

Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a natural flow. For the Group Steiner Tree problem, we show the integrality ratio is (log2 k), where k denotes the number is tight. For the Directed Steiner Tree problem, our results imply an ( log2 n (log log n)2 ) integrality

Kortsarz, Guy

265

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

E-print Network

. Your efforts will provide the groundwork for a successful and satisfying tree planting projectwww.ForestConnect.com Northeastern Tree Planting & Reforestation 1 Northeastern Tree Planting;2 Northeastern Tree Planting & Reforestation www.ForestConnect.com TABLE OF CONTENTS Chapter 1 ­ Recommended

Keinan, Alon

266

Breanne Mc Ivor The Mango Tree  

E-print Network

that a tree so generous Could never refuse us its ripe children to eat For, if it could, it would feed even Tantalus. The frequent sticky thrill of that first bite of fruit While propped against the tree trunk, kept, preserving those Old childhood traditions of tree climbing delight Fruit eating and the inevitably ripped

Robertson, Stephen

267

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

268

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

269

Mining optimal decision trees from itemset lattices  

Microsoft Academic Search

We present DL8, an exact algorithm for flnding a decision tree that optimizes a ranking function under size, depth, accuracy and leaf constraints. Because the discovery of op- timal trees has high theoretical complexity, until now no efiorts have been made to compute such trees for real-world datasets. An exact algorithm is of both scientiflc and prac- tical interest. From

Siegfried Nijssen; Élisa Fromont

2007-01-01

270

Decision Tree Learning Goals for the lecture  

E-print Network

lookahead in decision tree search #12;A decision tree to predict heart disease thal #_major_vessels > 0 one outcome of the test Each leaf predicts y or P(y | x) #12;Decision tree exercise Suppose x1 ... x5

Page Jr., C. David

271

Tree Protection During Construction and Landscaping Activities  

Microsoft Academic Search

In this chapter you will learn about the impact of construction activity on the long-term health of trees. We will discuss the obvious physical damage that may occur to the above ground portions of the tree. More importantly we will discuss what is go- ing on in the below-ground portions of the tree after soil cuts, soil fi lls, soil

Todd Hurt

272

Research Summary Health Benefits of Street Trees  

E-print Network

Research Summary Health Benefits of Street Trees Street trees can have an important role the review found a growing body of research that generally confirms the existence of these benefits, economic This research aimed to: o Assess recent economic evidence of the health benefits provided by street trees

273

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

274

Data multiplexer using a tree switch  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

275

Original article Oak tree improvement in Indiana  

E-print Network

Original article Oak tree improvement in Indiana MV Coggeshall Indiana Department of Natural Resources, Vallonia State Nursery, Vallonia, IN 47281 USA Summary — Oak tree improvement in the state 11 species/year. The intent of this paper is to present an overview of the oak tree improvement pro

Paris-Sud XI, Université de

276

Approximability of Selected Phylogenetic Tree Problems  

E-print Network

-theoretic assumptions. For the Steiner Tree Problem in Phylogeny (STPP) and the Generalized Tree Alignment (GTA) problem of Generalized Tree Alignment (GTA). STPP is a variant of MP where the underlying genetic distance measure is the Ham- ming distance, that counts the number of di#27;ering characters. In GTA, the n species are given

Eckmiller, Rolf

277

Fault Tree Analysis Using Bit Manipulation  

Microsoft Academic Search

This paper describes an efficient technique for computerized fault-tree analysis. The technique is based upon binary coding of events and bit manipulation for tree reduction, reducing both computation time and computer storage requirements. The operations include generation of minimal cut sets for trees containing arbitrary AND and OR logic, and determination of top event existence probability for s-independent minimal cut

Dean B. Wheeler; Jason S. Hsuan; Ralph R. Duersch; Glenn M. Roe

1977-01-01

278

Fault tree analysis with fuzzy gates  

Microsoft Academic Search

Fault tree analysis is an important tool analyzing system reliability. Fault trees consist of gates and events. Gates mean relationships between events. In fault tree analysis, AND, OR gates have been used as typical gates but it is often difficult to model the system structure with the two gates because in many cases we have not exact knowledge on system

HanSuk Pan; WonYoung Yun

1997-01-01

279

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

280

Safety Requirements and Fault Trees using Retrenchment  

E-print Network

. Veri#12;cation techniques such as Fault Tree Analysis can then be used to establish the root causeSafety Requirements and Fault Trees using Retrenchment R. Banach and R. Cross Computer Science trees for the faults introduced during the injection process. A two bit adder example drawn from

Banach, Richard

281

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

282

Skip B-Trees Ittai Abraham1  

E-print Network

and exploiting spatial as well as temporal locality in searches. Much of academic work on peer-to-peer systems-Tree, that combines the advantages of skip graphs with features of traditional B- trees. A skip B-Tree provides for the nearest node to a target hash using some sort of routing algorithm. The major form of variation between

Aspnes, James

283

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

284

"Dangerous" urban trees & community health & safety  

E-print Network

"Dangerous" urban trees & community health & safety Norman Dandy Forest Research #12;Urban trees against immediate threats to human health and safety, but weak governance to protect against longer are removed for health and safety reasons" (London Assembly 2007: 4) · falling branches / trees, · tripping

285

Mechanical stability of trees under dynamic loads  

Microsoft Academic Search

Tree stability in windstorms and tree failure are important issues in urban areas where there can be risks of damage to people and property and in forests where wind damage causes economic loss. Current methods of managing trees, including pruning and assessment of mechanical strength, are mainly based on visual assessment or the experience of people such as trained arborists.

KENNETH R. JAMES; NICHOLAS HARITOS; PETER K. ADES

2006-01-01

286

Minimum Steiner Tree Construction Gabriel Robins  

E-print Network

variations of the corresponding fundamental Steiner minimal tree (SMT) problem, where a given set of pins on the Steiner problem, about which hundreds of papers and several entire books were written [21, 25, 26, 29, 48 of P. The Steiner minimal tree problem can be formulated as follows. The Steiner Minimal Tree (SMT

Robins, Gabriel

287

Improved approximations for the Steiner tree problem  

Microsoft Academic Search

For a set S contained in a metric space, a Steiner tree of S is a tree that connects the points in S. Finding a minimum cost Steiner tree is an NP-hard problem in euclidean and rectilinear metrics as well as in graphs. We give an approximation algorithm and show that the worst-case ratio of the cost of our solutions

Piotr Berman; Viswanathan Ramaiyer

1992-01-01

288

Revised May 2008 Wildlife/Danger Tree  

E-print Network

) for assessing dangerous trees and evaluating wildlife habitat value in forestry, non-urban park, and wildlandRevised May 2008 Wildlife/Danger Tree Assessor's Course Workbook Forest Harvesting and Silviculture Course Module An initiative of the: Wildlife Tree Committee of British Columbia in cooperation with

Northern British Columbia, University of

289

New decision tree based on genetic algorithm  

Microsoft Academic Search

The decision tree based on the k-means algorithm has recently been proposed. However, the drawback of the k-means algorithm is that the users must determine the number of branches for each node before the decision tree is designed. The users are usually hard to determine the number of branches for each node. In this study, the new decision tree with

Shiueng-Bien Yang; Shen-I Yang

2010-01-01

290

Parallel Genetic Programming for Decision Tree Induction  

E-print Network

Parallel Genetic Programming for Decision Tree Induction Gianluigi Folino, Clara Pizzuti with the task of data classification by evolving decision trees [4, 8, 9, 16, 15, 2]. In genetic programming 2 shows how genetic programming can be used to inductively generate decision trees. In section 3

Fernandez, Thomas

291

Fault Tree XML {syjsmk, ldalove, jbyoo}@konkuk.ac.kr  

E-print Network

. 1. (FTA, Fault Tree Analysis) / , [1]. , . 1 FTA . 1. FTA(Fault Tree Analysis)[1] XML . XML [2]. (FT, Fault Tree) XML Fault Tree Analysis", Transactions of Korean Nuclear Society, vol.1, Pages 855-857, 2010 #12;

292

On the Hardness of Full Steiner Tree Problems Ahmad Biniaz  

E-print Network

On the Hardness of Full Steiner Tree Problems Ahmad Biniaz Anil Maheshwari Michiel Smid May 28 is a Steiner tree in which each vertex of R is a leaf. The full Steiner tree problem is to find a full Steiner tree with minimum weight. The bottleneck full Steiner tree problem is to find a full Steiner tree which

Smid, Michiel

293

Batch-mode Supervised Learning Decision tree induction  

E-print Network

Batch-mode Supervised Learning Decision tree induction Homework Applied inductive learning... (1/12) #12;Batch-mode Supervised Learning Decision tree induction Homework Batch-mode Supervised Learning Decision tree induction Tree growing Scoring a split Tree pruning Regression trees Homework Louis

Wehenkel, Louis

294

Red-Black Trees 11/11/2004 10:02 AM Red-Black Trees 1 2004 Goodrich, Tamassia  

E-print Network

Red-Black Trees 11/11/2004 10:02 AM 1 Red-Black Trees 1© 2004 Goodrich, Tamassia Red-Black Trees 6 3 8 4 v z Red-Black Trees 2© 2004 Goodrich, Tamassia From (2,4) to Red-Black Trees A red-black tree is a representation of a (2,4) tree by means of a binary tree whose nodes are colored red or black In comparison

Alechina, Natasha

295

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

E-print Network

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

Alechina, Natasha

296

Anatomical modeling of the bronchial tree  

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

297

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

298

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

299

Tree decompositions and social graphs  

E-print Network

Recent work has established that large informatics graphs such as social and information networks have non-trivial tree-like structure when viewed at moderate size scales. Here, we present results from the first detailed empirical evaluation of the use of tree decomposition (TD) heuristics for structure identification and extraction in social graphs. Although TDs have historically been used in structural graph theory and scientific computing, we show that---even with existing TD heuristics developed for those very different areas---TD methods can identify interesting structure in a wide range of realistic informatics graphs. Among other things, we show that TD methods can identify structures that correlate strongly with the core-periphery structure of realistic networks, even when using simple greedy heuristics; we show that the peripheral bags of these TDs correlate well with low-conductance communities (when they exist) found using local spectral computations; and we show that several types of large-scale "...

Adcock, Aaron B; Mahoney, Michael W

2014-01-01

300

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.

2007-08-02

301

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 B.

2011-01-01

302

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

303

Cover trees for nearest neighbor  

Microsoft Academic Search

Abstract We present a tree data structure for fast nearest neighbor operations in general n- point metric spaces (where the data set con- sists of n points). The data structure re- quires O(n) space regardless of the met- ric’s structure yet maintains all performance properties of a navigating net [KL04a]. If the point set has a bounded expansion con- stant

Alina Beygelzimer; Sham Kakade; John Langford

2006-01-01

304

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

305

Statistical Mechanics of Steiner Trees  

NASA Astrophysics Data System (ADS)

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.

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

2008-07-01

306

Tree climbing and human evolution  

PubMed Central

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

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

2013-01-01

307

Computing the joint distribution of tree shape and tree distance for gene tree inference and recombination detection.  

PubMed

Ancestral recombination events can cause the underlying genealogy of a site to vary along the genome. We consider Bayesian models to simultaneously detect recombination breakpoints in very long sequence alignments and estimate the phylogenetic tree of each block between breakpoints. The models we consider use a dissimilarity measure between trees in their prior distribution to favor similar trees at neighboring loci. We show empirical evidence in Enterobacteria that neighboring genomic regions have similar trees. The main hurdle in using such models is the need to properly calculate the normalizing function for the prior probabilities on trees. In this work, we quantify the impact of approximating this normalizing function as done in biomc2, a hierarchical Bayesian method to detect recombination based on distance between tree topologies. We then derive an algorithm to calculate the normalizing function exactly, for a Gibbs distribution based on the Robinson-Foulds (RF) distance between gene trees at neighboring loci. At the core is the calculation of the joint distribution of the shape of a random tree and its RF distance to a fixed tree. We also propose fast approximations to the normalizing function, which are shown to be very accurate with little impact on the Bayesian inference. PMID:24384712

Chung, Yujin; Perna, Nicole T; Ané, Cécile

2013-01-01

308

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

Microsoft Academic Search

This article compares the decision-tree algorithm (C5.0), neural decision-tree algorithm (NDT) and fuzzy decision-tree algorithm (FIDs) for addressing reservoir operations regarding water supply during normal periods. The conventional decision-tree algorithm, such as ID3 and C5.0, executes rapidly and can easily be translated into if-then-else rules. However, the C5.0 algorithm cannot discover dependencies among attributes and cannot treat the non-axis-parallel class

Chih-Chiang Wei; Nien-Sheng Hsu

2008-01-01

309

Topic Modeling with Nonparametric Markov Tree  

PubMed Central

A new hierarchical tree-based topic model is developed, based on nonparametric Bayesian techniques. The model has two unique attributes: (i) a child node in the tree may have more than one parent, with the goal of eliminating redundant sub-topics deep in the tree; and (ii) parsimonious sub-topics are manifested, by removing redundant usage of words at multiple scales. The depth and width of the tree are unbounded within the prior, with a retrospective sampler employed to adaptively infer the appropriate tree size based upon the corpus under study. Excellent quantitative results are manifested on five standard data sets, and the inferred tree structure is also found to be highly interpretable.

Chen, Haojun; Dunson, David B.; Carin, Lawrence

2013-01-01

310

Effective resistance of random trees  

Microsoft Academic Search

We investigate the effective resistance Rn<\\/sub> and conductance Cn<\\/sub> between the root and leaves of a binary tree of height n. In this electrical network, the resistance of each edge e at distance d from the root is defined by re<\\/sub>=2d<\\/sup>Xe<\\/sub> where the Xe<\\/sub> are i.i.d. positive random variables bounded away from zero and infinity. It is shown that ERn<\\/sub>=nEXe<\\/sub>?(Var?(Xe<\\/sub>)\\/EXe<\\/sub>)ln?n+O(1)

Louigi Addario-Berry; Nicolas Broutin; Gábor Lugosi

2009-01-01

311

Tree canopy radiance measurement system  

NASA Technical Reports Server (NTRS)

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

Caldwell, William; Vanderbilt, V. C.

1989-01-01

312

Can You Read a Tree?  

NSDL National Science Digital Library

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

Fries-Gaither, Jessica

2011-07-01

313

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

314

Hibernation by tree-roosting bats  

Microsoft Academic Search

In summer, long-eared bats (Nyctophilus spp.) roost under bark and in tree cavities, where they appear to benefit from diurnal heating of roosts. In contrast, hibernation\\u000a is thought to require a cool stable temperature, suggesting they should prefer thermally insulated tree cavities during winter.\\u000a To test this prediction, we quantified the winter thermoregulatory physiology and ecology of hibernating tree-roosting bats,

Christopher Turbill; Fritz Geiser

2008-01-01

315

Reconciliation with Non-Binary Species Trees  

PubMed Central

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

Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton

2008-01-01

316

Maximum Bounded Rooted-Tree Packing Problem  

E-print Network

Given a graph and a root, the Maximum Bounded Rooted-Tree Packing (MBRTP) problem aims at finding K rooted-trees that span the largest subset of vertices, when each vertex has a limited outdegree. This problem is motivated by peer-to-peer streaming overlays in under-provisioned systems. We prove that the MBRTP problem is NP-complete. We present two polynomial-time algorithms that computes an optimal solution on complete graphs and trees respectively.

Kerivin, Herve; Simon, Gwendal; Zhou, Fen

2011-01-01

317

Signs of Change: Studying Tree Rings  

NSDL National Science Digital Library

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

Colberg, Nancy; Change, Northern C.

318

The Giving Tree: Constructing Trees for Efficient Offline and Online Multi-Robot Coverage  

E-print Network

-robot coverage algorithms, and the online algorithm is proven to be robust. "And the tree was happy..." (Shel Silverstein, The Giving Tree) This work was funded in part by Israel's Ministry of Science and Technology 1

Kaminka, Gal A.

319

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

E-print Network

, and the tree project was a perfect trial project. To support this cooperative effort, theWarner College the website; and finally to utilize the online tree inventory to support teaching and learning. Online

320

Tree-Structured Infinite Sparse Factor Model  

PubMed Central

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

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

2013-01-01

321

[Potential ecological risks of transgenic trees].  

PubMed

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

Kang, Xiangyang; Liu, Zhimin; Li, Shenggong

2004-07-01

322

Tree Trunk Diameter to Branch Height Relationship  

NSDL National Science Digital Library

In this activity (located on page 2 of the PDF), learners will identify a group of deciduous trees to study. Once the species has been recorded, the circumference of the trunks will be measured at the same spot on each tree, as well as the height of the lowest branch. Then learners will calculate the diameter and analyze the result to look for a relationship between tree diameter and height of the lowest branch. This activity exposes learners to techniques that foresters actually use to study and measure trees. Relates to the linked video, DragonflyTV GPS: Temperate Rain Forest.

Twin Cities Public Television, Inc.

2007-01-01

323

Tree ring record chronicles major Mesoamerican droughts  

NASA Astrophysics Data System (ADS)

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

Tretkoff, Ernie

2011-05-01

324

Tree Genetics & Genomes ISSN 1614-2942  

E-print Network

maternal trees were examined. DNA fingerprinting and parentage analyses based on nine microsatellites per hybridization . SSR fingerprinting . Prezygotic barriers . Bloom synchrony . Conspecific pollen advance . Floral

325

Multicriteria Steiner Tree Problem for Communication Network  

E-print Network

This paper addresses combinatorial optimization scheme for solving the multicriteria Steiner tree problem for communication network topology design (e.g., wireless mesh network). The solving scheme is based on several models: multicriteria ranking, clustering, minimum spanning tree, and minimum Steiner tree problem. An illustrative numerical example corresponds to designing a covering long-distance Wi-Fi network (static Ad-Hoc network). The set of criteria (i.e., objective functions) involves the following: total cost, total edge length, overall throughput (capacity), and estimate of QoS. Obtained computing results show the suggested solving scheme provides good network topologies which can be compared with minimum spanning trees.

Levin, Mark Sh

2011-01-01

326

Transpiration and whole-tree conductance in ponderosa pine trees of different heights  

Microsoft Academic Search

Changes in leaf physiology with tree age and size could alter forest growth, water yield, and carbon fluxes. We measured tree\\u000a water flux (Q) for 14 ponderosa pine trees in two size classes (12 m tall and ?40 years old, and 36 m tall and ? 290 years old) to determine\\u000a if transpiration (E) and whole-tree conductance (g\\u000a t) differed

Michael G. Ryan; Barbara J. Bond; Beverly E. Law; Robert M. Hubbard; David Woodruff; Emil Cienciala; Jiri Kucera

2000-01-01

327

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

SciTech Connect

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

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

2013-04-01

328

Induction of Quadratic Decision Trees using Genetic Algorithms and k-D Trees  

Microsoft Academic Search

Genetic Algorithm-based Quadratic Decision Tree (GA-based QDT) has been applied successfully in various classification problems with non-linear class boundaries. However, the execution time of GA-based QDT is quite long. In this paper, a new version of GA-based QDT, called Genetic Algorithm-based Quadratic Decision Tree with k-D Tree (GA-based QDT with k-D Tree), is proposed. In the proposed algorithm, a k-D

SAI-CHEONG NG; KWONG-SAK LEUNG

329

A tree grows in Seattle.  

PubMed

In 1975 in Seattle, Washington, a nonprescription contraceptive specialty shop known as the Rubber Tree opened as a nonprofit project of the Seattle Chapter of Zero Population Growth. A visit to the shop confirms the logic of the concept that unhealthy attitudes toward contraceptives, particularly condoms, are reinforced when the products are not sold openly. The shop's clientele - the only shop of its kind in the U.S. - has steadily grown over 3 years; an estimated 7000 person were served last year. Inside the shop, situated on a quiet residential street, there are brightly packaged contraceptives attractively arranged on shelves as well as colorful posters, T-shirts, and bumper stickers bearing population control messages, and a variety of books dealing with human sexuality and family planning. In addition to making nonprescription contraceptives easily available and working to abolish social taboos, the Rubber Tree's mission includes the dissemination of medically accurate information in the hope of reducing the incidence of venereal disease and unplanned pregnancies. The shop also has a mail-order service to help increase the availability of contraceptives and family planning information in small towns and rural areas. PMID:12335437

1978-01-01

330

LS(Graph & Tree): A Local Search Framework for Constraint Optimization on Graphs and Trees  

E-print Network

LS(Graph & Tree): A Local Search Framework for Constraint Optimization on Graphs and Trees Pham University Providence, RI 02912, USA pvh@cs.brown.edu ABSTRACT LS(Graph & Tree) is a local search framework which aims at simplifying the modeling of Constraint Satisfaction Opti- mization Problems on graphs

Deville, Yves

331

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 duty on local authorities to protect trees in the public interest. However, it does not prescribe how-scale community evaluations, but can also handle urban woodlands. Funding/support Funded by the Forestry

332

Effects of Pruning on the Apple Tree: from Tree Architecture to D. Fumey1ab  

E-print Network

1 Effects of Pruning on the Apple Tree: from Tree Architecture to Modeling D. Fumey1ab , P.E. Lauri INRIA, Equipe Virtual Plant, Montpellier, France Keywords: Malus x domestica Borkh, Structure-Function Plant Model, tree training, pruning. Abstract Arboricultural practices such as pruning, artificial

Boyer, Edmond

333

Trees in Bangladesh paddy fields. 2. Survival of trees planted in crop fields  

Microsoft Academic Search

The design and methods are described of farmer-managed action-research to test the survival and performance of trees planted in paddy fields of private farms in Bangladesh. Farmers received seedlings of indigenous and exotic trees with extension advice on planting methods and care. Planting was done in systematically designed randomized modules involving twelve thousand trees up to the end of 1990.

D. Hocking; K. Islam

1995-01-01

334

A First Look at Tree Decay An Introduction to How Injury and Decay Affect Trees  

E-print Network

and other tree parts. Photosynthesis also removes carbon dioxide and adds oxygen to the atmosphere. Decay are protective for the tree but "stain" and reduce the value of wood for lumber. Large wounds at the base of the trunk cause the greatest injury to the tree and the greatest loss of timber value from stain and decay

335

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

E-print Network

trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computesInferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full of Biostatistics, Mailman School of Public Health, Columbia University *Corresponding author: E-mail: david

Rosenberg, Noah

336

Node-Weighted Steiner Tree and Group Steiner Tree in Planar Graphs  

E-print Network

optimization problems in planar graphs. For node-weighted Steiner tree, a classical network other op- timization problems such as Steiner forest, prize-collecting Steiner tree, and network-formation games. The second problem we address is group Steiner tree: given a graph with edge weights

Demaine, Erik

337

NodeWeighted Steiner Tree and Group Steiner Tree in Planar Graphs  

E-print Network

optimization problems in planar graphs. For node­weighted Steiner tree, a classical network other op­ timization problems such as Steiner forest, prize­collecting Steiner tree, and network­formation games. The second problem we address is group Steiner tree: given a graph with edge weights

Demaine, Erik

338

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

E-print Network

evolutionary model, en- abling predictions about gene tree patterns that the evolutionary process is expected] are unranked, in that they consider only the topological relationship among gene lineages, and not the sequence of evolutionary modeling and in species tree inference problems. Our interest in ranked gene tree topologies

Rosenberg, Noah

339

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

ERIC Educational Resources Information Center

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

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

340

GIS product reliability analysis based fuzzy fault tree  

Microsoft Academic Search

The paper imports fuzzy fault tree into GIS product reliability analysis for the fist time. The paper discusses how GIS product reliability analysis uses fuzzy fault tree method, mainly researches two problems that is GIS product fuzzy fault tree construction and analysis step of GIS product fuzzy fault tree; uses example to adopt fuzzy fault tree method processing GIS product

Xianfeng Ye; Youjian Hu; Shengwu Hu

2011-01-01

341

Cyber Threat Trees for Large System Threat Cataloging and Analysis*  

E-print Network

Cyber Threat Trees for Large System Threat Cataloging and Analysis* P. Ongsakorn, K. Turney, M Diagram (MDD). The cyber threat tree structure improves upon both the classical fault tree and attack tree and classification. To address this need, we propose an extension to the well-known fault tree representation

Thornton, Mitchell

342

"NH Big Tree of the Month November 2006" Witch Hazel  

E-print Network

"NH Big Tree of the Month ­ November 2006" Witch Hazel By Anne Krantz, NH Big Tree Team UNH Cooperative Extension Witch­hazel, Hamamelis virginiana, is the New Hampshire Big Tree for November, because. Currently the only recorded New Hampshire witch hazel tree on the NH Big Tree Registry is on the UNH campus

New Hampshire, University of

343

The Trade-offs of Multicast Trees and Algorithms  

Microsoft Academic Search

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

Liming Wei; Deborah Estrin

1995-01-01

344

Faster Steiner Tree Computation in Polynomial-Space  

E-print Network

nodes, the NP-hard Steiner tree problem is to compute a minimum-size tree which spans the terminals. All ) to O(1.36n ). 1 Introduction The Steiner tree problem is one of the best-known optimization problems] for an overview of the results and applications of the Steiner tree problem. The Steiner tree problem is known

Kratsch, Dieter

345

Carbon dynamics in trees: feast or famine?  

PubMed

Research on the degree to which carbon (C) availability limits growth in trees, as well as recent trends in climate change and concurrent increases in drought-related tree mortality, have led to a renewed focus on the physiological mechanisms associated with tree growth responses to current and future climate. This has led to some dispute over the role of stored non-structural C compounds as indicators of a tree's current demands for photosynthate. Much of the uncertainty surrounding this issue could be resolved by developing a better understanding of the potential functions of non-structural C stored within trees. In addition to functioning as a buffer to reconcile temporal asynchrony between C demand and supply, the storage of non-structural C compounds may be under greater regulation than commonly recognized. We propose that in the face of environmental stochasticity, large, long-lived trees may require larger C investments in storage pools as safety margins than previously recognized, and that an important function of these pools may be to maintain hydraulic transport, particularly during episodes of severe stress. If so, survival and long-term growth in trees remain a function of C availability. Given that drought, freeze-thaw events and increasing tree height all impose additional constraints on vascular transport, the common trend of an increase in non-structural carbohydrate concentrations with tree size, drought or cold is consistent with our hypothesis. If the regulated maintenance of relatively large constitutive stored C pools in trees serves to maintain hydraulic integrity, then the minimum thresholds are expected to vary depending on the specific tissues, species, environment, growth form and habit. Much research is needed to elucidate the extent to which allocation of C to storage in trees is a passive vs. an active process, the specific functions of stored C pools, and the factors that drive active C allocation to storage. PMID:22302370

Sala, Anna; Woodruff, David R; Meinzer, Frederick C

2012-06-01

346

Trees from trees: construction of phylogenetic supertrees using clann.  

PubMed

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

Creevey, Christopher J; McInerney, James O

2009-01-01

347

Detecting coevolution without phylogenetic trees? Tree-ignorant metrics of coevolution perform as well as tree-aware metrics  

PubMed Central

Background Identifying coevolving positions in protein sequences has myriad applications, ranging from understanding and predicting the structure of single molecules to generating proteome-wide predictions of interactions. Algorithms for detecting coevolving positions can be classified into two categories: tree-aware, which incorporate knowledge of phylogeny, and tree-ignorant, which do not. Tree-ignorant methods are frequently orders of magnitude faster, but are widely held to be insufficiently accurate because of a confounding of shared ancestry with coevolution. We conjectured that by using a null distribution that appropriately controls for the shared-ancestry signal, tree-ignorant methods would exhibit equivalent statistical power to tree-aware methods. Using a novel t-test transformation of coevolution metrics, we systematically compared four tree-aware and five tree-ignorant coevolution algorithms, applying them to myoglobin and myosin. We further considered the influence of sequence recoding using reduced-state amino acid alphabets, a common tactic employed in coevolutionary analyses to improve both statistical and computational performance. Results Consistent with our conjecture, the transformed tree-ignorant metrics (particularly Mutual Information) often outperformed the tree-aware metrics. Our examination of the effect of recoding suggested that charge-based alphabets were generally superior for identifying the stabilizing interactions in alpha helices. Performance was not always improved by recoding however, indicating that the choice of alphabet is critical. Conclusion The results suggest that t-test transformation of tree-ignorant metrics can be sufficient to control for patterns arising from shared ancestry. PMID:19055758

2008-01-01

348

CRITIQUE OF CARBON BASED TREE GROWTH MODELS  

EPA Science Inventory

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

349

LIABILITY FOR DAMAGE CAUSED BY HAZARDOUS TREES  

Microsoft Academic Search

Summarized are the general principles of law that courts use to determine who is liable when tree defects result in personal injury or property damage. Three procedures to minimize liability—tree inspection, documentation of inspec- tion, and adoption of other urban forestry practices—are discussed.

L. M. Anderson; Thomas A. Eaton

1986-01-01

350

Reliability evaluation based on fuzzy fault tree  

Microsoft Academic Search

In conventional fault tree analysis (FTA), some complex and uncertain events such as human errors cannot be handled effectively. Fuzzy fault tree analysis (fuzzy FTA) integrating fuzzy set evaluation and probabilistic estimation is proposed to evaluate vague events. The reliability of water supply subsystem in fire protection systems is analyzed using the proposed approach and the results prove the validity

Guo-zhu MAOI; Jia-wei Tu; Hui-bin Du

2010-01-01

351

Simaroubaceae (Quassia family) Tree-of-heaven  

E-print Network

. Leaflets are spear-shaped, 2 to 6 inches long, dark green above and pale green below. Leaf margins, yellowish to reddish brown and either smooth or downy. Bark is thin, smooth and pale to dark gray. Damaged Seeds and prolific vegetative sprouts. Tree-of-heaven continued Tree-of-heaven weedy habit. #12;

352

Intraspecific gene genealogies: trees grafting into networks  

Microsoft Academic Search

Intraspecific gene evolution cannot always be represented by a bifurcating tree. Rather, population genealogies are often multifurcated, descendant genes coexist with persistent ancestors and recombination events produce reticulate relationships. Whereas traditional phylogenetic methods assume bifurcating trees, several networking approaches have recently been developed to estimate intraspecific genealogies that take into account these population-level phenomena.

David Posada; Keith A. Crandall

2001-01-01

353

The Arctic Tree Line and Climate Change  

E-print Network

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

Blouin-Demers, Gabriel

354

Monte-Carlo Game Tree Search  

Microsoft Academic Search

Abstract Introducing the original ideas of using Monte-Carlo simulation in computer Go. Adding new ideas to pure Monte-Carlo approach for computer Go. • Progressive pruning • All moves as first heuristic • Temperature • Simulated annealing • Depth-2 tree search Parallel Monte-Carlo tree search Conclusion: • With the ever-increasing power of computers, we can add more knowl- edge to the

Tsan-sheng Hsu

355

Random Walks and Percolation on Trees  

Microsoft Academic Search

There is a way to define an average number of branches per vertex for an arbitrary infinite locally finite tree. It equals the exponential of the Hausdorff dimension of the boundary in an appropriate metric. Its importance for probabilistic processes on a tree is shown in several ways, including random walk and percolation, where it provides points of phase transition.

Russell Lyons

1990-01-01

356

A Dichromatic Framework for Balanced Trees  

Microsoft Academic Search

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

Leonidas J. Guibas; Robert Sedgewick

1978-01-01

357

On-Line Construction of Suffix Trees  

Microsoft Academic Search

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

Esko Ukkonen

1995-01-01

358

First Tree Cutting; Beginning of Construction  

NASA Technical Reports Server (NTRS)

Work crews saw down one of the first trees on May 17, 1963, signaling the beginning of construction of the Mississippi Test Facility in Hancock County, Miss. The tree was cut in Devil's Swamp near the site where the construction dock was built on the turn basin of the man-made canal system.

1963-01-01

359

Tree Construction using Singular Value Decomposition  

E-print Network

) from numerical linear algebra. Starting with an alignment of n DNA sequences, we show that SVD allows, statistically consistent algorithm for phylogenetic tree con- struction that uses the algebraic theory-life (ENCODE) data. 19.1 The general Markov model We assume that evolution follows a tree Markov model

Eriksson, Nicholas

360

Random trees Jean-Franois Le Gall  

E-print Network

-Watson branching processes and other random processes describing the evolution of populations) Mathematical biology relating random walks to Brownian motion. Jean-François Le Gall (Université Paris-Sud) Random treesRandom trees Jean-François Le Gall Université Paris-Sud Orsay and Institut universitaire de France

Le Gall, Jean-François

361

Limit of random walks of random trees  

E-print Network

Limit of random walks and of random trees -------------------- Elements -------------------- Graz (quantum physics, magnetism, polymer, DNA, genealogical tree, random walk, Markov chain, etc.); in computer physics, biology, a lot of objects hav- ing a discrete nature appear for various reason. In statistical

Marckert, Jean-François

362

Can Landsat imagery detect tree line dynamics?  

Microsoft Academic Search

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

Yangjian Zhang; Ming Xu; Jonathan Adams; Xiaochun Wang

2009-01-01

363

Efficiently mining frequent trees in a forest  

Microsoft Academic Search

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

Mohammed Javeed Zaki

2002-01-01

364

On Tree-Constrained Matchings and Generalizations  

E-print Network

-Constrained Bipartite Matching problem: Given two rooted trees T1 = (V1, E1), T2 = (V2, E2) and a weight function w : V1, rooted trees, approximation algorithms, local ratio technique, inapproximability, computational biology 1 important biological processes, such as tis- sue repair, the analysis of drug performance, and immune system

Elbassioni, Khaled

365

Deforestation: Transforming programs to eliminate trees  

E-print Network

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

Wadler, Philip

366

Concurrent manipulation of binary search trees  

Microsoft Academic Search

The concurrent manipulation of a binary search tree is considered in this paper. The systems presented can support any number of concurrent processes which perform searching, insertion, deletion, and rotation (reorganization) on the tree, but allow any process to lock only a constant number of nodes at any time. Also, in the systems, searches are essentially never blocked. The concurrency

H. T. Kung; Philip L. Lehman

1980-01-01

367

Sewing string tree vertices with ghosts  

E-print Network

It is shown how to sew string vertices with ghosts at tree level in order to produce new tree vertices using the Group Theoretic approach to String Theory. It is then verified the BRST invariance of the sewn vertex and shown that it has the correct ghost number.

L. Sandoval Jr

1999-09-22

368

Trees in the Web of Life  

PubMed Central

Reconstructing the 'Tree of Life' is complicated by extensive horizontal gene transfer between diverse groups of organisms. While numerous conceptual and technical obstacles remain, a report in this issue of Journal of Biology from Koonin and colleagues on the largest-scale prokaryotic genomic reconstruction yet attempted shows that such a tree is discernible, although its branches cannot be traced. PMID:19664165

Swithers, Kristen S; Gogarten, J Peter; Fournier, Gregory P

2009-01-01

369

Silicon implementation of an artificial dendritic tree  

Microsoft Academic Search

The silicon implementation of an artificial passive dendritic tree which can be used to process and classify dynamic signals is described. The electrical circuit architecture is modeled after complex neurons in the vertebrate brain which have spatially extensive dendritic tree structures that support large numbers of synapses. The circuit is primarily analog and, as in the biological model system, is

John G. Elias; Hsu-Hua Chu; Samer M. Meshreki

1992-01-01

370

A statistical approach to decision tree modeling  

Microsoft Academic Search

A statistical approach to decision tree modeling is described. In this approach, each decision in the tree is modeled parametrically as is the process by which an output is generated from an input and a sequence of decisions. The resulting model yields a likelihood measure of goodness of fit, allowing ML and MAP estimation techniques to be utilized. An efficient

Michael I. Jordan

1994-01-01

371

Fault tree analysis for software design  

Microsoft Academic Search

We present a study on software fault tree analysis (SFTA) conducted at the Software Assurance Technology Center at NASA Goddard Space Flight Center. While researchers have made various attempts at SFTA, software assurance practitioners have been slow to adopt it. One reason is the intense manual effort needed to identify and draw the fault trees for the code of large

Massood Towhidnejad; Dolores R. Wallace; Albert M. Gallo

2002-01-01

372

Reliability computation using fault tree analysis  

NASA Technical Reports Server (NTRS)

A method is presented for calculating event probabilities from an arbitrary fault tree. The method includes an analytical derivation of the system equation and is not a simulation program. The method can handle systems that incorporate standby redundancy and it uses conditional probabilities for computing fault trees where the same basic failure appears in more than one fault path.

Chelson, P. O.

1971-01-01

373

Symbolic Fault Tree Analysis for Reactive Systems  

Microsoft Academic Search

Fault tree analysis is a traditional and well-established technique for analyzing system design and robustness. Its purpose is to identify sets of basic events, called cut sets, which can cause a given top level event, e.g. a system malfunction, to occur. Generating fault trees is particularly critical in the case of reactive systems, as hazards can be the result of

Marco Bozzano; Alessandro Cimatti; Francesco Tapparo

2007-01-01

374

Decomposition Methods for Fault Tree Analysis  

Microsoft Academic Search

Some kinds of fault tree analysis are described for which cut set enumeration is inadequate. Modularization leads to more efficient computer programs, and also identifies subsystems which are intuitively meaningful. The problem of finding all modules of a fault tree is formulated as as extension of the problem of finding all ``cut-points'' of an undirected graph. The major result is

Arnon Rosenthal

1980-01-01

375

Thin Junction Trees Francis R. Bach  

E-print Network

with thin junction trees---models that are characterized by an upper bound on the size of the maximal involving low­order marginal or conditional probabilities--- e.g., naive independence models, trees­order depen­ dencies in data, either within the maximum entropy setting---in which features are se­ lected [9

Jordan, Michael I.

376

A Contour Method on Cayley tree  

E-print Network

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

U. A. Rozikov

2006-11-15

377

PCFG models of linguistic tree representations  

Microsoft Academic Search

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

Mark Johnson

1998-01-01

378

SPECIES DIFFER IN RESPONSES TO TREE SHELTERS  

Microsoft Academic Search

Effects of tree shelters on height, caliper, and di- ameter at breast height of 11 landscape tree species and cul- tivars were investigated in 2 nurseries during a 4-year period; the ratio of height to caliper was calculated as an indicator of trunk sturdiness. Species differed greatly in their responses, ranging in the fourth year from none to 44% and

Henry D. Gerhold

379

Bootstrap Confidence Levels for Phylogenetic Trees  

Microsoft Academic Search

Evolutionary trees are often estimated from DNA or RNA sequence data. How much confidence should we have in the estimated trees? In 1985, Felsenstein [Felsenstein, J. (1985) Evolution 39, 783-791] suggested the use of the bootstrap to answer this question. Felsenstein's method, which in concept is a straightforward application of the bootstrap, is widely used, but has been criticized as

Bradley Efron; Elizabeth Halloran; Susan Holmes

1996-01-01

380

Error Mining on Dependency Trees Claire Gardent  

E-print Network

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

Paris-Sud XI, Université de

381

APICAL BUD STRENGTH TESTS AND TREE SWAY  

E-print Network

shape) Canopy Gaps Interspecies competition "One species terminal or lateral branches can be knocked://www.treetechno.co.uk/#/treeterms/4521071322 Often under emphasized in forestry education. Size and shape are a dynamic relationship Productive of photosynthate dictates shape and size of all other parts of a tree #12;10/27/2010 2 Tree crown edges impacting

Gray, Matthew

382

The "Ride for Russia" Tree Lichen Survey  

ERIC Educational Resources Information Center

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

Young, Simon

2013-01-01

383

Decision Tree Learning read Chapter 3  

E-print Network

Learning, c Tom M. Mitchell, McGraw Hill, 1997 #12;Decision Tree for PlayTennis Outlook Overcast Humidity, c Tom M. Mitchell, McGraw Hill, 1997 #12;A Tree to Predict C-Section Risk Learned from medical_Presentation = 3: 8+,22-] .27+ .73- 48 lecture slides for textbook Machine Learning, c Tom M. Mitchell, McGraw Hill

Steels, Luc

384

Tools for the Rectilinear Steiner Tree Problem.  

National Technical Information Service (NTIS)

A Rectilinear Minimal Steiner Tree (RMST) for a set V of n points is a tree which connects the points of V using line segments parallel to the horizontal and vertical coordinate axes that has the shortest possible total length. Techniques are presented id...

C. M. Jonker, V. C. J. Disselkoen

1990-01-01

385

TAX: A Tree Algebra for XML  

Microsoft Academic Search

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

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

2001-01-01

386

Repeater Insertion in Tree Structured Inductive Interconnect  

E-print Network

of the interconnect with technology scaling. Meanwhile, the gate parasitic impedances decrease due to the shrinking of this paper. An algorithm is introduced to insert and size repeaters within an RLC tree to optimize a variety.7%, respectively, for a variety of copper­based interconnect trees from a 0.25 µµm CMOS technology. The average

Ismail, Yehea

387

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;TRACE Tree Rings in Archaeology, Climatology and Ecology Volume 11 Proceedings Rings in Archaeology, Climatology and Ecology) organized by the GFZ German Research Centre

Biondi, Franco

388

Parallel Genetic Programming for Decision Tree Induction  

Microsoft Academic Search

A parallel genetic programming approach to induce decision trees in large data sets is presented. A population of trees is evolved by employing the genetic operators and every individual is evaluated by using a fitness function based on the J-measure. The method is able to deal with large data sets since it uses a parallel implementation of genetic programming through

Gianluigi Folino; Clara Pizzuti; Giandomenico Spezzano

2001-01-01

389

Fuzzy decision trees: issues and methods  

Microsoft Academic Search

Decision trees are one of the most popular choices for learning and reasoning from feature-based examples. They have undergone a number of alterations to deal with language and measurement uncertainties. We present another modification, aimed at combining symbolic decision trees with approximate reasoning offered by fuzzy representation. The intent is to exploit complementary advantages of both: popularity in applications to

Cezary Z. Janikow

1998-01-01

390

Induction on Decision Trees Sance IDT  

E-print Network

Induction on Decision Trees Séance « IDT » de l'UE « apprentissage automatique » Bruno Bouzy bruno.bouzy@parisdescartes.fr www.mi.parisdescartes.fr/~bouzy #12;Induction on Decision Trees Outline · Induction task · ID3 · Entropy (disorder) minimization · Noise · Unknown attribute values · Selection criterion #12;Induction

Bouzy, Bruno

391

Steiner trees and spanning trees in six-pin soap films  

NASA Astrophysics Data System (ADS)

The problem of finding minimum (local as well as absolute) path lengths joining given points (or terminals) on a plane is known as the Steiner problem. The Steiner problem arises in finding the minimum total road length joining several towns and cities. We study the Steiner tree problem using six-pin soap films. Experimentally, we observe spanning trees as well as Steiner trees partly by varying the pin diameter. We propose a possibly exact expression for the length of a spanning tree or a Steiner tree, which fails mysteriously in certain cases.

Dutta, Prasun; Khastgir, S. Pratik; Roy, Anushree

2010-02-01

392

Induction of Linear Decision Trees with Real-Coded Genetic Algorithms and k-D Trees  

Microsoft Academic Search

\\u000a Although genetic algorithm-based decision tree algorithms are applied successfully in various classification tasks, their\\u000a execution times are quite long on large datasets. A novel decision tree algorithm, called Real-Coded Genetic Algorithm-based\\u000a Linear Decision Tree Algorithm with k-D Trees (RCGA-based LDT with kDT), is proposed. In the proposed algorithm, a k-D tree\\u000a is built when a new node of a linear

Ng Sai-cheong; Kwong-sak Leung

2005-01-01

393

Dynamic asset trees and portfolio analysis  

NASA Astrophysics Data System (ADS)

The minimum spanning tree, based on the concept of ultrametricity, is constructed from the correlation matrix of stock returns and provides a meaningful economic taxonomy of the stock market. In order to study the dynamics of this asset tree we characterise it by its normalised length and by the mean occupation layer, as measured from an appropriately chosen centre called the `central node'. We show how the tree evolves over time, and how it shrinks strongly, in particular, during a stock market crisis. We then demonstrate that the assets of the optimal Markowitz portfolio lie practically at all times on the outskirts of the tree. We also show that the normalised tree length and the investment diversification potential are very strongly correlated.

Onnela, J.-P.; Chakraborti, A.; Kaski, K.; Kertiész, J.

2002-12-01

394

Goods-thinking vs. tree-thinking  

PubMed Central

While it has become increasingly clear that the Tree of Life hypothesis has limitations in its ability to describe the evolution of all evolving entities on the planet, there has been a marked reluctance to move away from the tree-based language. Ironically, while modifying the idea of the Tree of Life to the extent that it is only very distantly related to its original descriptions, there has been a very careful attempt to retain the language of tree-thinking. The recent movement away from a tree-thinking language toward a goods-thinking language and perspective is a significant improvement. In this commentary, we describe how goods-thinking can provide better descriptions of evolution, can integrate evolution with environment more closely and can offer an equal place for Mobile Genetic Elements and chromosomal elements in discussions of evolutionary history. PMID:22545244

McInerney, James; Cummins, Carla; Haggerty, Leanne

2011-01-01

395

Fuzzy variable-branch decision tree  

NASA Astrophysics Data System (ADS)

Decision trees and their variants recently have been proposed. All trees used are fixed M-ary tree structured, such that the training samples in each node must be artificially divided into a fixed number of branches. This work proposes a fuzzy variable-branch decision tree (FVBDT) based on the fuzzy genetic algorithm (FGA). The FGA automatically searches for the proper number of branches of each node according to the classification error rate and the classification time of FVBDT. Therefore, FGA reduces both the classification error rate and classification time, and then optimizes the FVBDT. In our experiments, FVBDT outperforms the traditional C-fuzzy decision tree (CFDT) based on the fuzzy C-means (FCM) algorithm.

Yang, Shiueng-Bien

2010-10-01

396

29 CFR 788.7 - “Planting or tending trees.”  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false âPlanting or tending trees.â 788.7 Section 788.7 Labor ...EMPLOYED § 788.7 “Planting or tending trees.” Employees employed in “planting or tending trees” include those engaged in...

2012-07-01

397

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

398

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

399

29 CFR 788.7 - “Planting or tending trees.”  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false âPlanting or tending trees.â 788.7 Section 788.7 Labor ...EMPLOYED § 788.7 “Planting or tending trees.” Employees employed in “planting or tending trees” include those engaged in...

2011-07-01

400

29 CFR 788.7 - “Planting or tending trees.”  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false âPlanting or tending trees.â 788.7 Section 788.7 Labor ...EMPLOYED § 788.7 “Planting or tending trees.” Employees employed in “planting or tending trees” include those engaged in...

2010-07-01

401

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

402

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

403

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

404

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

405

Street Trees, Overhead Utlitly Distribution, and Physical Infrastructure  

E-print Network

Street Trees, Overhead Utlitly Distribution, and Physical Infrastructure: Design Implictions Street Tree Planting ..............88 Monetary benefits Aesthetic considerations Design implementation Two The State of The Art- Review of Current Street Tree Planting and Maintenance Practice Background

Schweik, Charles M.

406

A-3 First Tree Cutting  

NASA Technical Reports Server (NTRS)

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

2007-01-01

407

Robins gather in a tree  

NASA Technical Reports Server (NTRS)

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

2000-01-01

408

Time and space-optimality in B-trees  

Microsoft Academic Search

A B-tree is compact if it is minimal in number of nodes, hence has optimal space utilization, among equally capacious B-trees of the same order. The space utilization of compact B-trees is analyzed and compared with that of noncompact B-trees and with (node)-visit-optimal B-trees, which minimize the expected number of nodes visited per key access. Compact B-trees can be as

Arnold L. Rosenberg; Lawrence Snyder

1981-01-01

409

Böhm-Like Trees for Term Rewriting Systems  

Microsoft Academic Search

\\u000a In this paper we define Böhm-like trees for term rewriting systems (TRSs). The definition is based on the similarities between\\u000a the Böhm trees, the Lévy-Longo trees, and the Berarducci trees. That is, the similarities between the Böhm-like trees of the\\u000a ?-calculus. Given a term t a tree partially represents the root-stable part of t as created in each maximal fair

Jeroen Ketema

2004-01-01

410

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

NASA Astrophysics Data System (ADS)

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

Wei, Chih-Chiang; Hsu, Nien-Sheng

2008-02-01

411

Accumulation of PCB Congeners in Nestling Tree Swallows  

E-print Network

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

McCarty, John P.

412

Benefits of tree mixes in carbon plantings  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

413

A Modified TreePM Code  

E-print Network

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

Nishikanta Khandai; J. S. Bagla

2008-02-21

414

Reconciliation of Gene and Species Trees  

PubMed Central

The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i) inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii) trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii) can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree. PMID:24800245

Rusin, L. Y.; Lyubetskaya, E. V.; Gorbunov, K. Y.; Lyubetsky, V. A.

2014-01-01

415

Reconciliation of gene and species trees.  

PubMed

The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i) inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii) trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii) can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree. PMID:24800245

Rusin, L Y; Lyubetskaya, E V; Gorbunov, K Y; Lyubetsky, V A

2014-01-01

416

Urban tree effects on soil organic carbon.  

PubMed

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

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

2014-01-01

417

Exploiting graph properties of game trees  

SciTech Connect

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

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

1996-12-31

418

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

PubMed Central

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

Coutand, Catherine; Dupraz, Christian; Jaouen, Gaelle; Ploquin, Stephane; Adam, Boris

2008-01-01

419

Comprehensive Decision Tree Models in Bioinformatics  

PubMed Central

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

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

2012-01-01

420

Tree Edit Distance Problems: Algorithms and Applications to Bioinformatics  

NASA Astrophysics Data System (ADS)

Tree structured data often appear in bioinformatics. For example, glycans, RNA secondary structures and phylogenetic trees usually have tree structures. Comparison of trees is one of fundamental tasks in analysis of these data. Various distance measures have been proposed and utilized for comparison of trees, among which extensive studies have been done on tree edit distance. In this paper, we review key results and our recent results on the tree edit distance problem and related problems. In particular, we review polynomial time exact algorithms and more efficient approximation algorithms for the edit distance problem for ordered trees, and approximation algorithms for the largest common sub-tree problem for unordered trees. We also review applications of tree edit distance and its variants to bioinformatics with focusing on comparison of glycan structures.

Akutsu, Tatsuya

421

Chlorinated ethenes from groundwater in tree trunks  

USGS Publications Warehouse

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

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

1999-01-01

422

Type I Error Control for Tree Classification  

PubMed Central

Binary tree classification has been useful for classifying the whole population based on the levels of outcome variable that is associated with chosen predictors. Often we start a classification with a large number of candidate predictors, and each predictor takes a number of different cutoff values. Because of these types of multiplicity, binary tree classification method is subject to severe type I error probability. Nonetheless, there have not been many publications to address this issue. In this paper, we propose a binary tree classification method to control the probability to accept a predictor below certain level, say 5%.

Jung, Sin-Ho; Chen, Yong; Ahn, Hongshik

2014-01-01

423

Algorithms for optimal dyadic decision trees  

SciTech Connect

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

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

2009-01-01

424

The decision tree approach to classification  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

425

IND - THE IND DECISION TREE PACKAGE  

NASA Technical Reports Server (NTRS)

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

Buntine, W.

1994-01-01

426

Controlling Tree Squirrels in Urban Areas  

E-print Network

T ree squirrels inhabit many parts of Texas. The three types of tree squirrels found in the state are the fox squirrel, the gray squir- rel and the flying squirrel. Tree squirrels are interesting animals, but in urban and suburban areas... there are no toxicants or fumi- gants registered for use against tree squirrels in Texas. Registered commercial repellents are available. Shooting It is not advisable to shoot squirrels in urban areas because of the danger to other animals and people. Also, most cities...

Texas Wildlife Services

2006-09-06

427

Tree Death Study's Climate Change Connections  

SciTech Connect

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

McDowell, Nate

2012-09-10

428

Pendelluft in the bronchial tree.  

PubMed

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

Greenblatt, Elliot E; Butler, James P; Venegas, Jose G; Winkler, Tilo

2014-11-01

429

Maryland R-tree Demo  

NSDL National Science Digital Library

This tool can be used to visualize a number of different decompositions. The main visualization window is zoomable and the user can optionally overlay it with a grid. There are a number of operations that can be performed. Users can insert, move and delete rectangles that define the structure. In addition, the user can perform three test, near, within and overlap. For the tests, the user is given the option of what kind of shape to use for the test: point, rectangle, polygon, path, etc. The application of the tests is animated, with controls given for pausing the animation and controlling the speed. In addition, the animation can be made to stop at logical phase points (such as when an object is encountered. Users can easily enter rectangles and see the R-tree deocmposition. Unfortunately, there is very little feedback about what is going on. It would be a big help if there were some form of textual log that explains the steps taking place. Even some kind of description of the basic operations would be good. The interface is generally good, but has some confusing aspects. There is helpful explanatory text on the page to give some background. Recommended as lecture aide, standalone, self-study suppliment to tutorial or lecture, debugging aide.

Samet, Hanan; Brabec, Frantisek

430

Current and potential tree locations in tree line ecotone of Changbai Mountains, Northeast China: the controlling effects of topography.  

PubMed

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

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

2014-01-01

431

Responses of twelve tree species common in Everglades tree islands to simulated hydrologic regimes  

Microsoft Academic Search

Twelve tree species common in Everglades tree islands were subjected to three hydrologic regimes under controlled conditions\\u000a for 25 weeks and assessed for growth and physiological responses. Treatments representing high, low, and no flood were maintained\\u000a in pools of water to mimic seasonal variation in water depths at different positions in tree islands. Soil inundation under\\u000a the high flood treatment

David T. Jones; Jay P. Sah; Michael S. Ross; Steven F. Oberbauer; Bernice Hwang; Krish Jayachandran

2006-01-01

432

The effect of conductivity distribution in tree channel on PD behavior in electrical tree  

Microsoft Academic Search

Under the conditions of long electrode distance or low applied voltage, a tree from the needle tip can not directly reach the plane electrode, and it begins to grow fast again when the partial discharge (PD) extincts. Prior to the PD extinction, the ?-q-n pattern of PD changes from wing-like (or triangle-like) pattern to turtle-like pattern. In a tree-like tree,

Kai Wu; Hengkun Xie; Y. Suzuoki; T. Mizutani

1998-01-01

433

Constructing event trees for volcanic crises  

USGS Publications Warehouse

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

Newhall, C.; Hoblitt, R.

2002-01-01

434

Practice Guide Raising trees and shrubs  

E-print Network

, the British Isles. Figure 1 Mother and daughter collecting horse chestnut seeds. Understanding tree seeds Most their potential to germinate, grow and develop into healthy plants, whereas mishandling will damage or kill them

435

Assembling the Tree of Life (ATOL)  

NSF Publications Database

... Directorate for Geosciences Directorate for Social, Behavioral, and Economic Sciences Directorate ... Assembling the Tree of Life (ATOL) To construct a phylogeny for the 1.7 million described species of ...

436

Optimal static pricing for a tree network  

E-print Network

We study the static pricing problem for a network service provider in a loss system with a tree structure. In the network, multiple classes share a common inbound link and then have dedicated outbound links. The motivation ...

Caro, Felipe

437

Deforestation: Transforming programs to eliminate trees  

E-print Network

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

Wadler, Philip

438

Tree Genetics & Genomes ISSN 1614-2942  

E-print Network

19 adjacent watersheds in the southern portion of butternut's range using 12 microsatellite markers of regeneration, and persistence of all remaining butternut trees, which still retain high levels of genetic

439

Phylogenetic Networks that Display a Tree Twice.  

PubMed

In the last decade, the use of phylogenetic networks to analyze the evolution of species whose past is likely to include reticulation events, such as horizontal gene transfer or hybridization, has gained popularity among evolutionary biologists. Nevertheless, the evolution of a particular gene can generally be described without reticulation events and therefore be represented by a phylogenetic tree. While this is not in contrast to each other, it places emphasis on the necessity of algorithms that analyze and summarize the tree-like information that is contained in a phylogenetic network. We contribute to the toolbox of such algorithms by investigating the question of whether or not a phylogenetic network embeds a tree twice and give a quadratic-time algorithm to solve this problem for a class of networks that is more general than tree-child networks. PMID:25245396

Cordue, Paul; Linz, Simone; Semple, Charles

2014-10-01

440

Evolutionary Trees and phylogenetics: An algebraic perspective  

E-print Network

. MBE (1988) 5:626-644. Gorilla AAGCTTCACCGGCGCAGTTGTTCTTATAATTGCCCACGGACTTACATCAT... Orangutan_Mac. Chimpanzee Human Gorilla Orangutan Gibbon Squirrel_Monkey Tarsier 0.1 Evolutionary trees and phylogenetics 6 sequences: Gorilla AAGCTTCACCGGCGCAGTTGTTCTTATAATTGCCCACGGACTTACATCAT... Orangutan

Allman, Elizabeth S.

441

Worms and Trees: An Exciting Adventure.  

ERIC Educational Resources Information Center

Outlines procedures for using silkworms in elementary science, mathematics, history, ecology, social studies, language arts, art, and physical education. Also focuses on the silkworm's use of the mulberry tree. (DDR)

El Harim, Jean Love

1997-01-01

442

Urban Woodlands and Trees the Bristol Experience  

E-print Network

Urban Woodlands and Trees the Bristol Experience Russell Horsey ­ Deputy Director #12;#12;Know your Projects #12;Greater Bristol Bus Network #12;High Quality Design #12;Whiteladies Road #12;Whiteladies Road

443

a difference Please help us plant trees!  

E-print Network

.m.-1:00 p.m. Berry Brook Restoration Site Why? The trees will enhance the wildlife habitat along the newly created wetland and stream channel and help to filter pollutants and make the stream bank more

444

Tree Leaf Identification and Leaf Display Activity  

NSDL National Science Digital Library

This activity is a tree leaf collection, identification, and display of dried and pressed leaves. It teaches students about distinguishing leaf characteristics as well as a way to display and label their collection.

Hansing, Rebecca

445

Dealing with Storm-Damaged Trees  

E-print Network

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

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

2005-10-25

446

Hardwood Tree Improvement and Regeneration Center  

E-print Network

). Successful establishment of hardwood plantings requires planning, a commitment of time and resources, proper maintenance practices can greatly enhance the prospects for successful hardwood tree establishment. Planting Forest Service Department of Forestry and Natural Resources Purdue University Planting Hardwood Seedlings

447

Broadcasting on trees and the Ising model  

Microsoft Academic Search

Consider a process in which information is transmitted from a given\\u000aroot node on a noisy tree network $T$.We start with an unbiased random bit $R$\\u000aat the root of the tree and send it down the edges of $T$.On every edge the bit\\u000acan be reversed with probability $\\\\varepsilon$, and these errors occur\\u000aindependently. The goal is to reconstruct

William Evans; Claire Kenyon; Yuval Peres; Leonard J. Schulman

2000-01-01

448

The Tree and Shrub Genera of Borneo  

NSDL National Science Digital Library

James Jarvie of The Arnold Arboretum of Harvard University and Indonesian colleague Ermayanti of Conservation International have put together this database on the tree and shrub genera of Borneo. The illustrated database "offers a DELTA-based interactive key to the 534 tree genera of the island" and is available in English or Indonesian. Also included is a detailed, hyperlinked index of genera and a large selection of pen-and-ink images.

Ermayanti.; Jarvie, James K.

1995-01-01

449

Tree Ferns Biotechnology: From Spores to Sporophytes  

Microsoft Academic Search

\\u000a Tree ferns are typical for rain forest of tropical and subtropical climate and play a very crucial role in the ecology of\\u000a lands of origin and some of the ­species are economically very important due to various utilization by autochthons or citizens.\\u000a Majority of tree ferns are illegally collected from natural sites, which has resulted in the decrease of their

Jan J. Rybczy?ski; Anna Miku?a

450

Create Prime Factorization Trees with Little Alchemy  

NSDL National Science Digital Library

This lesson plan provides steps for using the open sandbox game Little Alchemy to teach Prime Factorization Trees. Little Alchemy is available as a free download or it can be opened in a webpage. The lesson plans includes a 3-minute video on how to create elements using the game. In addition to students making factor trees they can extend this lesson to write prime factorization in exponential form.

Molfino, Agustin

2013-04-16

451

Deforestation: Transforming Programs to Eliminate Trees  

Microsoft Academic Search

An algorithm that transforms programs to eliminate intermediate trees is presented.The algorithm applies to any term containing only functions with definitionsin a given syntactic form, and is suitable for incorporation in an optimising compiler.Intermediate lists---and, more generally, intermediate trees---are both the basis andthe bane of a certain style of programming in functional languages. For example, tocompute the sum of the

Philip Wadler

1990-01-01

452

Transgene stability and dispersal in forest trees  

Microsoft Academic Search

Transgenics from several forest tree species, carrying a number of commercially important recombinant genes, have been produced,\\u000a and are undergoing confined field trials in a number of countries. However, there are questions and issues regarding stability\\u000a of transgene expression and transgene dispersal that need to be addressed in long-lived forest trees. Variation in transgene\\u000a expression is not uncommon in the

Mulkh Raj Ahuja

2009-01-01

453

The path integral for dendritic trees  

Microsoft Academic Search

We construct the path integral for determining the potential on any dendritic tree described by a linear cable equation. This is done by generalizing Brownian motion from a line to a tree. We also construct the path integral for dendritic structures with spatially-varying and\\/or time-dependent membrane conductivities due, for example, to synaptic inputs. The path integral allows novel computational techniques

L. F. Abbott; Edward Farhi; Sam Gutmann

1991-01-01

454

Bulk Loading the M-tree  

Microsoft Academic Search

The M-tree is a dynamic paged structure that can be effec- tively used to index multimedia databases, where objects are represented by means of complex features and similarity queries require the compu- tation of time-consuming distance functions. The initial loading of the M-tree, however, can be very expensive. In this paper we propose a fast (bulk) loading algorithm to speed-up

Paolo Ciaccia; Marco Patella

1998-01-01

455

R-trees Have Grown Everywhere  

Microsoft Academic Search

bulk-loading. It seems that due to the modern demanding applications and after the academia has paved the way, recently the industry recognized the use and necessity of R-trees. The simplicity of the structure and its resemblance to the B-tree, allowed developers to easily incorporate the structure into existing database management systems in order to support spatial query processing. In this

YANNIS MANOLOPOULOS; ALEXANDROS NANOPOULOS; APOSTOLOS N. PAPADOPOULOS

456

Natural products as herbicides for tree establishment  

Microsoft Academic Search

Summary The selectivity and effi cacy of the foliar-acting natural-product herbicides bilanaphos and citronella oil were tested in comparison with glufosinate-ammonium. When applied to tree-base foliage of 10 species of broadleaved and coniferous trees in May or June they caused contact damage to the sprayed area only. Overall application of bilanaphos and glufosinate-ammonium and directed application of citronella oil to

D. V. Clay; F. L. DIXON; I. WILLOUGHBY

2005-01-01

457

Tungsten oxide tree-like structures  

Microsoft Academic Search

An interesting micrometer scale tree-like structure has been generated by heating a W foil, partly covered by a SiO2 plate, in an Ar atmosphere at ca. 1600°C. Upon sonication, the trees are broken into nanoneedles (ca. 5–50 nm wide and 20–200 nm long) and planar polyhedral nanoparticles (ca. 10–50 nm cross-section). Structural analysis, using ED, EDX, XRD, and HRTEM, showed

Yan Qiu Zhu; Weibing Hu; Wen Kuang Hsu; Mauricio Terrones; Nicole Grobert; Jonathan P Hare; Harold W Kroto; David R. M Walton; Humberto Terrones

1999-01-01

458

Planning effectiveness may grow on fault trees.  

PubMed

The first step of a strategic planning process--identifying and analyzing threats and opportunities--requires subjective judgments. By using an analytical tool known as a fault tree, healthcare administrators can reduce the unreliability of subjective decision making by creating a logical structure for problem solving and decision making. A case study of 11 healthcare administrators showed that an analysis technique called prospective hindsight can add to a fault tree's ability to improve a strategic planning process. PMID:10145509

Chow, C W; Haddad, K; Mannino, B

1991-10-01

459

Parallel object-oriented decision tree system  

DOEpatents

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

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

2006-02-28

460

GRFT - Genetic Records Family Tree Web Applet.  

PubMed

Current software for storing and displaying records of genetic crosses does not provide an easy way to determine the lineage of an individual. The genetic records family tree (GRFT) applet processes records of genetic crosses and allows researchers to quickly visualize lineages using a family tree construct and to access other information from these records using any Internet browser. Users select from three display features: (1) a family tree view which displays a color-coded family tree for an individual, (2) a sequential list of crosses, and (3) a list of crosses matching user-defined search criteria. Each feature contains options to specify the number of records shown and the latter two contain an option to filter results by the owner of the cross. The family tree feature is interactive, displaying a popup box with genetic information when the user mouses over an individual and allowing the user to draw a new tree by clicking on any individual in the current tree. The applet is written in JavaScript and reads genetic records from a tab-delimited text file on the server, so it is cross-platform, can be accessed by anyone with an Internet connection, and supports almost instantaneous generation of new trees and table lists. Researchers can use the tool with their own genetic cross records for any sexually reproducing organism. No additional software is required and with only minor modifications to the script, researchers can add their own custom columns. GRFT's speed, versatility, and low overhead make it an effective and innovative visualization method for genetic records. A sample tool is available at http://stanford.edu/walbot/grft-sample.html. PMID:22303311

Pimentel, Samuel; Walbot, Virginia; Fernandes, John

2011-01-01

461

Tree automata, mu-calculus and determinacy  

Microsoft Academic Search

It is shown that the propositional mu-calculus is equivalent in expressive power to finite automata on infinite trees. Since complementation is trivial in the mu-calculus, the equivalence provides a radically simplified, alternative proof of M.O. Rabin's (1989) complementation lemma for tree automata, which is the heart of one of the deepest decidability results. It is also shown how mu-calculus can

E. A. Emerson; C. S. Jutla

1991-01-01

462

Colorado River Droughts Inferred from Tree Rings  

Microsoft Academic Search

Tree-ring reconstructions for the Colorado River at Lee Ferry, Arizona, have consistently indicated that the modern gaged flow record is unrepresentative of the past few centuries both in the long-term mean annual flow and the severity of extended hydrologic droughts. Information on past droughts can be considered most reliable for the past 500 years, when tree-ring site coverage is relatively

D. M. Meko; C. A. Woodhouse

2007-01-01

463

Decision Tree Learning [read Chapter 3  

E-print Network

for textbook Machine Learning, c flTom M. Mitchell, McGraw Hill, 1997 #12; Decision Tree for P lay for textbook Machine Learning, c flTom M. Mitchell, McGraw Hill, 1997 #12; A Tree to Predict C­Section Risk+,22­] .27+ .73­ 48 lecture slides for textbook Machine Learning, c flTom M. Mitchell, McGraw Hill, 1997 #12

Mitchell, Tom

464

Clock tree synthesis for prescribed skew specifications  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . 10 B. Delay Balancing . . . . . . . . . . . . . . . . . . . . . . . . 11 III ALGORITHM : : : : : : : : : : : : : : : : : : : : : : : : : : : : 14 A. Review of the Deferred-Merge Embedding (DME) Algorithm 14 1. Bottom-Up Phase: Construction of the Tree... that can achieve exact zero skew for any given abstract tree. In order to further reduce wirelength, 4 the DME (Deferred Merge Embedding) algorithm was developed in [11] according to the observation that there are multiple locations for a merging node...

Chaturvedi, Rishi

2005-08-29

465

SIMULATING SIZE-CONSTRAINED GALTON-WATSON TREES Luc Devroye  

E-print Network

Devroye, School of Computer Science, McGill University, 3480 University Street, Montreal, Canada H3A 2K6 as a random simply generated tree picked uniformly from a set of such trees. That particular set depends a uniform random binary tree, or Catalan tree. The distribution (1/3, 1/3, 1/3) on {0, 1, 2} yields

Devroye, Luc

466

DEPTH PROPERTIES OF SCALED ATTACHMENT RANDOM RECURSIVE TREES  

E-print Network

FRAIMAN Abstract. We study depth properties of a general class of random recursive trees where each node i proof for the height of uniform random recursive trees Hn e log n that does not use branching random walks. 1. Introduction A uniform random recursive tree (urrt) Tn of order n is a tree with n + 1 nodes

Devroye, Luc

467

Enhancing the B+ -tree by Dynamic Node Popularity Caching  

E-print Network

1 Enhancing the B+ -tree by Dynamic Node Popularity Caching Cui Yu + James Bailey $ Julian * Troy University, USA Keywords: databases, data structures Abstract We propose the Cache Coherent B to the traditional B+ -tree. The CCB+ -tree makes use of the unused space in the internal nodes of a B+ -tree

Zhang, Rui

468

A Spring Playscape Project: Building a Tree Circle  

ERIC Educational Resources Information Center

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

Keeler, Rusty

2009-01-01

469

A Backup Tree Algorithm for Multicast Overlay Torsten Braun1  

E-print Network

the local connectivity, but it requires a sophisticated signaling protocol. 3. Central mode. The algorithm trees from the default multicast tree for application level multicast. For each backup multicast tree exactly one link of the default multicast tree is replaced by a backup link from the set of available

Braun, Torsten

470

The context-tree weighting method: basic properties  

Microsoft Academic Search

We describe a sequential universal data compressionprocedure for binary tree sources that performs the "doublemixture." Using a context tree, this method weights in an efficientrecursive way the coding distributions corresponding toall bounded memory tree sources, and achieves a desirablecoding distribution for tree sources with an unknown model andunknown parameters. Computational and storage complexity ofthe proposed procedure are both linear in

Frans M. J. Willems; Yuri M. Shtarkov; Tjalling J. Tjalkens

1995-01-01

471

NH Big Tree of the Month Chestnut Oak, Quercus prinus  

E-print Network

NH Big Tree of the Month Chestnut Oak, Quercus prinus By Anne Krantz - UNH Extension Big Tree Team of white oak. It has taken years to figure out this tree species, as oaks can hybridize or cross pollinate on the Hillsborough Big Tree Team. Recently, I made arrangements to re-measure a chestnut oak growing nearby

New Hampshire, University of

472

TREES AND HUMANKIND: CULTURAL AND PSYCHOLOGICAL BINDINGS I  

Microsoft Academic Search

NO VE MB ER 1996 To effectively educate people about trees and forests, natural resource managers must understand the beliefs and perceptions concerning trees and forests within different communities and cultures. The reverence and adoration of trees has a strong psychological and social foundation in most human cul- tures. The influence of trees and forests on cultural development can better

KIM CODER

1996-01-01

473

Automated fault tree analysis via AI\\/ES  

Microsoft Academic Search

A description is given of FTA, an interactive fault tree analysis tool that integrates the creation of fault trees with the propagation of failure rates. This tool allows the engineer to create, modify and manipulate fault trees easily, and requires little instruction on how to use the software. The fault trees generated are directly used in the propagation of failure

K. M. Kuzawinski; R. Smurthwaite

1988-01-01

474

Methodology for Computer-Aided Fault Tree Analysis  

Microsoft Academic Search

Fault tree analysis is a systematic, deductive and probabilistic risk assessment tool which elucidates the causal relations leading to a given undesired event. Quantitative fault tree (failure) analysis requires a fault tree and failure data of basic events. Development of a fault tree and subsequent analysis require a great deal of expertise, which may not be available all the time.

R. Ferdous; F. I. Khan; B. Veitch; P. R. Amyotte

2007-01-01

475

Page 1 of 8 Generation of Fault Trees from Simulated  

E-print Network

tree analysis is widely used in industry in fault diagnosis. The diagnosis of incipient or `soft of the approach. 1 Introduction Fault tree analysis (FTA) and fault tree synthesis (FTS) evolved primarily within for over 30 years. Fault tree analysis can be valuable as a design tool; using it to identify and eliminate

Madden, Michael

476

PROTECTION OF TREES FROM MAMMAL DAMAGE BPG NOTE 12  

E-print Network

PROTECTION OF TREES FROM MAMMAL DAMAGE BPG NOTE 12 Best Practice Guidance for Land Regeneration for sites with existing trees or where standard trees are to be planted. Tree protection in urban and peri vandalism can negate protection measures. Sometimes a policy of no animal management may be adopted (at

477

Configuration of ACK Trees for Multicast Transport Protocols  

Microsoft Academic Search

For scalable multicast transport, one of the promising approaches is to employ a control tree known as acknowl- edgement (ACK) tree which can be used to convey infor- mation on reliability and session status from receivers to a root sender. The existing tree configuration has focused on a 'bottom-up' scheme in which ACK trees grow from leaf receivers toward a

Seok Joo Koh Koh; Eunsook Kim Kim; Juyoung Park Park; Shin Gak Kang Kang; Ki Shik Park Park; Chee Hang Park Park

2001-01-01

478

Tree Rings: Counting the Years of Global Warming  

NSDL National Science Digital Library

This video describes the role that dendrochronology plays in understanding climate change, especially changes to high elevation environments at an upper tree line. Dendrochronologists from the Big Sky Institute sample living and dead trees, describe how correlations between trees are made, and explain how tree cores record climate changes.

Productions, Worksyn

479

Tree Axis Structure Simplification Correspondent to Botanical Properties  

Microsoft Academic Search

In order to describe the tree topology more efficiently for modeling and biological calculation, a ternary tree data structure is introduced in this paper. The data structure of a ternary tree and the topological structure of a real tree constitute a mapping, which presents the biological properties of plant axes and the relationships among plant axes of different tiers. The

Maojin Xie; Weiqun Cao; Gang Yang; Xinyuan Huang

2009-01-01

480

On Directed Steiner Trees Leonid Zosin \\Lambda Samir Khuller y  

E-print Network

Steiner tree problem is the following: given a directed graph G = (V; E) with weights on the edges, a set for it. Generaliza­ tions of Steiner trees, such as the directed Steiner tree problem and the group Steiner tree problem have only recently received attention in terms of worst case ap­ proximation

Khuller, Samir

481

New Approximation Algorithms for the Steiner Tree Problems  

E-print Network

New Approximation Algorithms for the Steiner Tree Problems Marek Karpinski \\Lambda Alexander Zelikovsky y Abstract The Steiner tree problem asks for the shortest tree connecting a given set of terminal points in a metric space. We design new approximation algorithms for the Steiner tree problems using

Karpinski, Marek

482

On Full Steiner Trees in Unit Disk Graphs Ahmad Biniaz  

E-print Network

as its leaves. The full Steiner tree problem is to find a full Steiner tree of G with minimum weight. In this paper we consider the full Steiner tree problem when G is a unit disk graph. We present a 20-approximation algorithm for the full Steiner tree problem in G. As for -precise unit disk graphs we present

Smid, Michiel

483

Two Heuristics for the Euclidean Steiner Tree Derek R. Dreyer  

E-print Network

Two Heuristics for the Euclidean Steiner Tree Problem Derek R. Dreyer Michael L. Overton September 30, 2002 Abstract The Euclidean Steiner tree problem is to find the tree with minimal Euclidean) points t1, . . . , tn in 2 , the Steiner tree problem is to find the shortest network (in the Euclidean

Dreyer, Derek

484

Efficient XML Keyword Search: From Graph Model to Tree Model  

E-print Network

Efficient XML Keyword Search: From Graph Model to Tree Model Yong Zeng # , Zhifeng Bao # , Tok Wang/IDREF is not considered, an XML document can be modeled as a tree. Keyword search on XML tree can be much more efficient tree search methods and invent new, but less efficient search methods for XML graph. To address

Ling, Tok Wang

485

Lossless fitness inheritance in genetic algorithms for decision trees  

Microsoft Academic Search

This paper shows that genetic algorithms can build decision trees very quickly, since some of the most obvious tree quality parameters are recursively computed and, therefore, can be re-used across generations of partially similar decision trees. We show that simply storing instance counters at decision tree leaves is enough for fitness to be piecewise computed in a lossless fashion. We

Dimitris Kalles; Athanassios Papagelis

2006-01-01

486

Evolving Fuzzy Decision Trees with Genetic Programming and Clustering  

E-print Network

Evolving Fuzzy Decision Trees with Genetic Programming and Clustering J. Eggermont Leiden Institute that were classi#12;ed. Related work on discovering fuzzy decision trees using tree-based genetic pro genetic programming is used to evolve a population of fuzzy decision trees for binary classi#12;cation

Fernandez, Thomas

487

On constructing a fuzzy inference framework using crisp decision trees  

Microsoft Academic Search

This paper proposes a framework which consists of a novel fuzzy inference algorithm to generate fuzzy decision trees from induced crisp decision trees. Fuzzy theoretical techniques are used to fuzzify crisp decision trees in order to soften sharp decision boundaries at decision nodes inherent in this type of trees. A framework for the investigation of various types of membership functions

Keeley A. Crockett; Zuhair Bandar; David Mclean; James O’Shea

2006-01-01

488

On Min-Power Steiner Tree  

E-print Network

In the classical (min-cost) Steiner tree problem, we are given an edge-weighted undirected graph and a set of terminal nodes. The goal is to compute a min-cost tree S which spans all terminals. In this paper we consider the min-power version of the problem, which is better suited for wireless applications. Here, the goal is to minimize the total power consumption of nodes, where the power of a node v is the maximum cost of any edge of S incident to v. Intuitively, nodes are antennas (part of which are terminals that we need to connect) and edge costs define the power to connect their endpoints via bidirectional links (so as to support protocols with ack messages). Differently from its min-cost counterpart, min-power Steiner tree is NP-hard even in the spanning tree case, i.e. when all nodes are terminals. Since the power of any tree is within once and twice its cost, computing a rho \\leq ln(4)+eps [Byrka et al.'10] approximate min-cost Steiner tree provides a 2rhoproblem. For mi...

Grandoni, Fabrizio

2012-01-01

489

A natural history of human tree climbing.  

PubMed

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

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

2014-06-01

490

ANTLR Tree Grammar Generator and Extensions  

NASA Technical Reports Server (NTRS)

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

Craymer, Loring

2005-01-01

491

New York University: A World Community of Old Trees  

NSDL National Science Digital Library

Hosted by New York University, this innovative website entitled A World Community of Old Trees was created by art educator and exhibiting visual artist, Dr. June Julian. This collaborative art project provides opportunities for students in grades K-12 to research a tree in their community, create art work about that tree, and submit the information and artwork for inclusion in the Tree Gallery section of the website. The Tree Gallery section also includes background for the project, examples of Dr. Julian's art, and other artists' representations of trees (including work from K-12 students from around the country and Ohio University students). The site links to Project Instructions for Students in Grades K-12 and printable Permission Forms. The site also links to the Tree Museum containing art history for tree images, and Tree Talk which provides a forum for sharing ecological information about ancient trees.

Julian, June

492

Integrality ratio for Group Steiner Trees and Directed Steiner Trees # Eran Halperin + Guy Kortsarz # Robert Krauthgamer Aravind Srinivasan  

E-print Network

Steiner Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a flow. For the Group Steiner Tree problem, we show the integrality ratio is#16 2 k), where k denotes the number is tight. This also applies for the Directed Steiner Tree problem. In terms of the number n of vertices

Krauthgamer, Robert

493

Integrality ratio for Group Steiner Trees and Directed Steiner Trees # Eran Halperin + Guy Kortsarz # Robert Krauthgamer # Aravind Srinivasan  

E-print Network

on the integrality ratio of the flow­based relaxation for the Group Steiner Tree problem, where k denotes the number as for its generalization, the Directed Steiner Tree problem. For the latter problem, our results imply design problem that generalizes both Set Cover and the Steiner Tree problem. The Directed Steiner Tree

Krauthgamer, Robert

494

Parallel Monte-Carlo Tree Search with Simulation Servers  

Microsoft Academic Search

Monte-Carlo tree search is a new best-first tree search algorithm that triggered a revolution in the computer Go world. Developing good parallel Monte-Carlo tree search algorithms is importan because single processor's performance cannot be expected to increase as used to. A novel parallel Monte-Carlo tree search algorithm is proposed. A tree searcher runs on a client computer and multiple Monte-Carlo

Hideki Kato; Ikuo Takeuchi

2010-01-01

495

Efficient Exploration of the Space of Reconciled Gene Trees  

PubMed Central

Gene trees record the combination of gene-level events, such as duplication, transfer and loss (DTL), and species-level events, such as speciation and extinction. Gene tree–species tree reconciliation methods model these processes by drawing gene trees into the species tree using a series of gene and species-level events. The reconstruction of gene trees based on sequence alone almost always involves choosing between statistically equivalent or weakly distinguishable relationships that could be much better resolved based on a putative species tree. To exploit this potential for accurate reconstruction of gene trees, the space of reconciled gene trees must be explored according to a joint model of sequence evolution and gene tree–species tree reconciliation. Here we present amalgamated likelihood estimation (ALE), a probabilistic approach to exhaustively explore all reconciled gene trees that can be amalgamated as a combination of clades observed in a sample of gene trees. We implement the ALE approach in the context of a reconciliation model (Szöll?si et al. 2013), which allows for the DTL of genes. We use ALE to efficiently approximate the sum of the joint likelihood over amalgamations and to find the reconciled gene tree that maximizes the joint likelihood among all such trees. We demonstrate using simulations that gene trees reconstructed using the joint likelihood are substantially more accurate than those reconstructed using sequence alone. Using realistic gene tree topologies, branch lengths, and alignment sizes, we demonstrate that ALE produces more accurate gene trees even if the model of sequence evolution is greatly simplified. Finally, examining 1099 gene families from 36 cyanobacterial genomes we find that joint likelihood-based inference results in a striking reduction in apparent phylogenetic discord, with respectively. 24%, 59%, and 46% reductions in the mean numbers of duplications, transfers, and losses per gene family. The open source implementation of ALE is available from https://github.com/ssolo/ALE.git. [amalgamation; gene tree reconciliation; gene tree reconstruction; lateral gene transfer; phylogeny.] PMID:23925510

Szollosi, Gergely J.; Rosikiewicz, Wojciech; Boussau, Bastien; Tannier, Eric; Daubin, Vincent

2013-01-01

496

Tree multicast strategies in mobile, multihop wireless networks  

Microsoft Academic Search

Tree multicast is a well established concept in wired networks. Two versions, per-source tree multicast (e.g., DVMRP) and shared tree multicast (e.g., Core Based Tree), account for the majority of the wireline implementations. In this paper, we extend the tree multicast concept to wireless, mobile, multihop networks for applications ranging from ad hoc networking to disaster recovery and battlefield. The

Mario Gerla; Lixia Zhang

1999-01-01

497

The Trade-offs of Multicast Trees and Algorithms  

Microsoft Academic Search

Multicast trees can be shared across sources (shared trees)or may be source-specific (shortest path trees). Inspired byrecent interests in using shared trees for interdomain multicasting,we investigate the trade-offs among shared treetypes and source specific shortest path trees, by comparingperformance over both individual multicast group and thewhole network. The performance is evaluated in terms ofpath length, link cost, and traffic concentration.We

Deborah Estrin; Liming Wei

1994-01-01

498

Fault tree analysis for maintenance needs  

NASA Astrophysics Data System (ADS)

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

Halme, Jari; Aikala, Antti

2012-05-01

499

Temperature histories from tree rings and corals  

SciTech Connect

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

Cook, E.R. [Tree-Ring Lab., Palisades, NY (United States)

1995-05-01

500

Up in the Tree - The Overlooked Richness of Bryophytes and Lichens in Tree Crowns  

PubMed Central

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

Boch, Steffen; Muller, Jorg; Prati, Daniel; Blaser, Stefan; Fischer, Markus

2013-01-01