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1

Cytotoxicity of urushiols isolated from sap of Korean lacquer tree ( Rhus vernicifera stokes)  

Microsoft Academic Search

Cytotoxicities of four urushiols, congeners isolated from the sap of Korean lacquer tree (Rhus vernicifera Stokes), to 29 human cancer cell lines originated from 9 organs were evaluated. Their values of 50% growth inhibition were\\u000a below 4 ?g\\/ml, and showed cell line specific cytotoxicity. The present result is the first report on the cytotoxicity of urushiols\\u000a suggesting that they would

Dong Ho Hong; Sang Bae Han; Chang Woo Lee; Se Hyung Park; Young Jin Jeon; Myong-Jo Kim; Sang-Soo Kwak; Hwan Mook Kim

1999-01-01

2

Titrations with ferrocyanide of japanese-lacquer-tree (Rhus vernicifera) laccase and of the type 2 copper-depleted enzyme. Interrelation of the copper sites.  

PubMed Central

1. Redox titrations are reported of the metal centres in Japanese-lacquer-tree (Rhus vernicifera) laccase with ferrocyanide. 2. The redox potential of Type 1 Cu was found to increase with ferrocyanide concentration up to a limiting value similar to that for the Type 1 Cu in Type 2 Cu-depleted enzyme (which is independent of ferrocyanide concentration). 3. The redox potential of the two-electron acceptor (Type 3 Cu) is also independent of ferrocyanide concentration in Type 2 Cu-depleted enzyme and lower than values reported for the native enzyme. 4. The two-electron acceptor is present in the oxidized state in the Type 2 Cu-depleted enzyme, though the latter lacks the 330 nm absorption band. 5. The redox potential of Type 2 Cu also depends on ferrocyanide concentration, at least in the presence of azide. 6. The redox potentials are affected by freezing the solutions and/or addition of azide, the latter binding to Type 2 Cu with affinity dependent on the redox state of the two-electron acceptor.

Morpurgo, L; Graziani, M T; Desideri, A; Rotilio, G

1980-01-01

3

In vitro Antibacterial and Morphological Effects of the Urushiol Component of the Sap of the Korean lacquer tree (Rhus vernicifera Stokes) on Helicobacter pylori  

PubMed Central

Eradication regimens for Helicobacter pylori infection have some side effects, compliance problems, relapses, and antibiotic resistance. Therefore, alternative anti-H. pylori or supportive antimicrobial agents with fewer disadvantages are necessary for the treatment of H. pylori. We investigated the pH-(5.0, 6.0, 7.0, 8.0, 9.0, and 10.0) and concentration (0.032, 0.064, 0.128, 0.256, 0.514, and 1.024 mg/mL)-dependent antibacterial activity of crude urushiol extract from the sap of the Korean lacquer tree (Rhus vernicifera Stokes) against 3 strains (NCTC11637, 69, and 219) of H. pylori by the agar dilution method. In addition, the serial (before incubation, 3, 6, and 10 min after incubation) morphological effects of urushiol on H. pylori were examined by electron microscopy. All strains survived only within pH 6.0-9.0. The minimal inhibitory concentrations of the extract against strains ranged from 0.064 mg/mL to 0.256 mg/mL. Urushiol caused mainly separation of the membrane, vacuolization, and lysis of H. pylori. Interestingly, these changes were observed within 10 min following incubation with the 1×minimal inhibitory concentrations of urushiol. The results of this work suggest that urushiol has potential as a rapid therapeutic against H. pylori infection by disrupting the bacterial cell membrane.

Suk, Ki Tae; Kim, Hyun Soo; Kim, Moon Young; Kim, Jae Woo; Uh, Young; Jang, In Ho; Kim, Soo Ki; Choi, Eung Ho; Kim, Myong Jo; Joo, Jung Soo

2010-01-01

4

Optical properties of japanese-lacquer-tree (Rhus vernicifera) laccase depleted of type 2 copper(II). Involvement of type-2 copper(II) in the 330nm chromophore.  

PubMed Central

1. Spectroscopic and functional properties of Japanese-lacquer-tree (Rhus vernicifera) laccase were re-investigated, with special emphasis on the relationships between the different types of copper centres (Types 1, 2, and 3). 2. On removal of the Type 2 Cu(II), a decrease of absorbance occurred in the wavelength region above 650 nm (delta epsilon 750 = 300 M-1 . cm-1) and around 330 nm (delta episom 330 up to 2200 M-1 . cm-1). 3. Reductive titrations with ascorbic acid or ferrocyanide showed that the electron-accepting capacity of the partial apoprotein is one electron-equivalent lower than that of the native protein, i.e. the protein two-electron acceptor is present in the oxidized state in spite of absorbance loss at 330 nm. 4. The 330 nm chromophore apparently depends on the presence of both the Type 2 and the Type 3 copper in the oxidized state. 5. This finding may have implications in the relative location of Type 2 and 3 copper centres and on the redox behaviour of laccase.

Morpurgo, L; Graziani, M T; Finazzi-Agro, A; Rotilio, G; Mondovi, B

1980-01-01

5

Clinical features of 31 patients with systemic contact dermatitis due to the ingestion of Rhus (lacquer).  

PubMed

In Korea, Rhus has been used as a folk medicine to cure gastrointestinal diseases and as a health food. We review the clinicopathological and laboratory findings in patients with systemic contact dermatitis caused by intake of Rhus. We reviewed medical records and histopathological sections from 31 patients during a 10-year period. The male/female ratio was 1.4: 1 and the average age was 43.8 years (range 22-70). Ten patients (32%) had a known history of allergy to lacquer. Rhus was ingested to treat gastrointestinal problems including indigestion and gastritis (45%), and as a health food (39%), in cooked meat, in herbal medicine, or taken by inhalation. The patients developed skin lesions such as a maculopapular eruption (65%), erythema multiforme (EM, 32%), erythroderma (19%), pustules, purpura, weals and blisters. Erythroderma was very frequent in patients with a known history of allergy to lacquer, but maculopapular and EM-type eruptions were more frequently observed in those without a history of allergy. All patients experienced generalized or localized pruritus. Other symptoms included gastrointestinal problems (32%), fever (26%), chills and headache; many developed leucocytosis (70%) with neutrophilia (88%), while some showed toxic effects on liver and kidney. Fifty-nine per cent of patients observed cutaneous or general symptoms within a day after ingestion of Rhus. There was no difference in the time lag for symptoms to develop between patients allergic and not allergic to Rhus. All patients responded well to treatment with systemic steroids and antihistamines. Common histopathological findings were vascular dilatation, perivascular lymphohistiocytic infiltration, and extravasation of red blood cells in the upper dermis. Rhus lacquer should not be ingested in view of its highly allergic and toxic effects. PMID:10809851

Park, S D; Lee, S W; Chun, J H; Cha, S H

2000-05-01

6

Effects of lacquer polysaccharides, glycoproteins and isoenzymes on the activity of free and immobilised laccase from Rhus vernicifera.  

PubMed

The purified polysaccharides, glycoproteins, and isoenzymes of Rhus laccase, and crude enzymes, from Chinese lacquer (Rhus vernicifera sap) were used to determine their influence on the enzymic activity of Rhus laccase on several substrates (4-phenylenediamine, isoeugenol and coniferyl alcohol). No product identity changes were observed when these components were added singularly or in combination to the enzymic reactions (only relative product yields varied significantly), however, the polysaccharides (GP1 and GP2) and glycoprotein (stellacyanin, St) exhibited negative effects, and the two isoenzymes (L1 and L2) exhibited positive synergistic effects, on the activity of Rhus laccase. With respect to the activity of the crude enzymes, the negative effects of GP1, GP2 and St were greater than the positive effects of L1 and L2, compared with free Rhus laccase on its own (using 4-phenylenediamine as substrate), the estimated inhibitory effect (of GP1, GP2 and St) being by at least a factor of 50 (even with the positive effect of L1 and L2). This contributes to understanding of lacquer storage stability and drying rates. Immobilisation of crude enzymes using a variety of techniques (using natural and modified polysaccharides, and an inorganic support) where evaluated using isoeugenol as substrate. Agar embedding and zirconium chloride chelation methods resulted in the highest substrate conversion levels. The yields and products of isoeugenol catalysis using Vietnamese crude enzymes/purified Rhus laccase and commercial Denilite laccase were also compared and contrasted with their Chinese lacquer sap equivalents. PMID:20363247

Wan, Yun-Yang; Lu, Rong; Akiyama, Kazuhiro; Okamoto, Katsuhisa; Honda, Takayuki; Du, Yu-Min; Yoshida, Takashi; Miyakoshi, Tetsuo; Knill, Charles J; Kennedy, John F

2010-04-02

7

Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols  

PubMed Central

Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera) from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110?kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

Lu, Rong; Miyakoshi, Tetsuo

2012-01-01

8

Lacquer poisoning  

MedlinePLUS

... a varnish) that is often used to give wooden surfaces a glossy look. Lacquers are dangerous to ... that are used as a clear finish for wooden surfaces, particularly floors. They are sold under various ...

9

A Leafhopper ( Hishimonus sellatus ) Transmits Phylogenetically Distant Phytoplasmas: Rhus Yellows and Hovenia Witches' Broom Phytoplasma  

Microsoft Academic Search

  Phytoplasmas causing a severe decline of three tree species, i.e., Rhus javanica, Hovenia tomentella and Zizyphus jujuba, in Japan were examined for their transmissibility by a leafhopper species Hishimonus sellatus, and for their phylogenetic relatedness. By H. sellatus, Rhus yellows (RhY) phytoplasma was transmissible to white clover and periwinkle seedlings, causing typical symptoms in these\\u000a plants. Jujube witches' broom (JWB)

Manabu KUSUNOKI; Toshiki SHIOMI; Motowo KOBAYASHI; Torao OKUDAIRA; Akihiro OHASHI; Teruo NOHIRA

2002-01-01

10

Polymerized Urushiol of the Commercially Available Rhus Product in Korea  

PubMed Central

Background Systemic contact dermatitis commonly occurs with the intake of rhus (boiled chicken with rhus) as a health food and a folk medicine to cure gastrointestinal diseases in Korea. Rhus companies insist they have the technology for rhus detoxification. However, the numbers of systemic allergic contact dermatitis patients, caused by rhus, have not decreased. The principle of present techniques for rhus detoxification is the induction of the polymerization of urushiol, but polymerized urushiol may still have antigenicity, although to a diminished degree. The Korean Food and Drug Administration (KFDA) has a regulation to control urushiol use as a food. However, the laboratory method that KFDA uses for detection of rhus can only detect the urushiol monomer. Objective We conducted experiments to detect polymerized urushiol in rhus products, which were considered not to include urushiol by the KFDA. Methods Rhus product approved by the KFDA was separated with chloroform. The chloroform fractionation was accomplished on a recycle HPLC system. Four peaks were achieved and evaporated to give an amorphous powder. Each powder was analyzed on a NMR system and mass spectrometer. Results The material considered to be urushiol dimer, with a 638 molecular weight (MW), was detected in one of the four powders as per the HPLC peaks. Conclusion We concluded that commercially available rhus product is comprised of material considered to be urushiol dimer. Therefore, even if the antigenicity of the rhus products is low, this product may cause adverse effects and is not completely detoxified.

Cheong, Seung Hyun; Choi, You Won; Min, Byung Sun

2010-01-01

11

Cardanols from leaves of Rhus thyrsiflora.  

PubMed

A mixture of 3-substituted alkyl- and alkenylphenols including nine new compounds (cardanols) was isolated from leaves of the Yemenian plant Rhus thyrsiflora (Anacardiaceae) and identified by GC-MS. The position of the double bond in the compounds bearing a monolefinic side chain was determined by their typical MS fragmentation patterns after hydroxylation and trimethylsilylation. PMID:11488469

Franke, K; Masaoud, M; Schmidt, J

2001-07-01

12

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...180.1179 Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica...biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...

2010-07-01

13

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...180.1179 Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica...biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus...

2009-07-01

14

A CONDIMENT (SUMAC (RHUS CORIARIA L.) FRUITS): SOME PHYSICOCHEMICAL PROPERTIES  

Microsoft Academic Search

Sumac (Rhus coriaria L.) is a perennial edible plant, which is grow- ing wild. In the present research, the proximate physical and chemical prop- erties of sumac fruits along with their mineral constituents were studied. The analyses of sumac fruits showed the following composition: moisture (9.6%), oil (7.4 %), protein (2.6 %), fibre (14.6 %), ash (1.8%) and water-soluble extract

Musa Özcan; Haydar Haciseferogullari

15

40 CFR 180.1179 - Plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...  

Code of Federal Regulations, 2013 CFR

...lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria mangle; exemption from the requirement of a tolerance. The biochemical pesticide plant extract derived from Opuntia lindheimeri, Quercus falcata, Rhus aromatica, and Rhizophoria...

2013-07-01

16

Transungual delivery of ketoconazole using novel lacquer formulation.  

PubMed

Onychomycosis, a common fungal infection of the nail, can have a substantial impact on quality of life. The success of topical therapy for onychomycosis depends on effective penetration, which can be enhanced using an appropriate delivery method. This study evaluated the effectiveness of a novel topical lacquer on enhancing [(14)C]-ketoconazole penetration by comparing nail absorption, nail distribution, and nail penetration of [(14)C]-ketoconazole dissolved in the novel lacquer versus a commercial ketoconazole cream. Using the in vitro finite dose model, the formulations were applied daily to human nail plates for 7 days. Drug absorption was measured by monitoring rate of appearance in each nail layer and the supporting bed. After the multiple day treatment, cumulative concentrations of ketoconazole formulated in novel lacquer in the deep nail layer and the nail bed were significantly greater than cumulative concentrations of commercial ketoconazole (p<0.05), as well as several orders of magnitude greater than the minimal inhibitory concentration (MIC) deemed necessary to inhibit the growth of causative dermatophytic and yeast species. These results suggest that this novel ketoconazole lacquer has the potential to be an effective topical treatment for onychomycosis. PMID:24029171

Hafeez, Farhaan; Hui, Xiaoying; Chiang, Audris; Hornby, Sidney; Maibach, Howard

2013-09-09

17

New galloyl derivative from winged sumac (Rhus copallinum) fruit.  

PubMed

Twelve compounds were isolated from Winged Sumac (Rhus copallinum) fruit and their structures were elucidated on the basis of NMR and mass spectral data. The isolates included a new galloyl derivative, (R)-galloyl malic acid dimethyl ester (1), and eleven known compounds, gallic acid (2), methyl gallate (3), glucogallin (4), methyl m-digallate (5), methyl p-digallate (6), quercetin (7), myricetin (8), rhamnazin (9), kaempferol (10), betulinic acid (11), and oleanolic acid (12). All of the compounds were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, Caco-2) and nontumorigenic (CCD18-Co) cell lines. PMID:22428241

Ma, Hang; Yuan, Tao; González-Sarrías, Antonio; Li, Liya; Edmonds, Maxwell E; Seeram, Navindra P

2012-01-01

18

[Respiratory pathology induced by inhalation of hair lacquer].  

PubMed

On the basis of a critical analysis of the literature, the authors review the various respiratory lesions imputed to the inhalation of hair lacquers. Pulmonary thesaurismosis is alleged to result from accumulation in the pulmonary parenchyma of non-biodegradable macro-molecules, such as PVP. Only isolated cases have been published and the true existence of this disease remains to be confirmed, in the absence of convincing epidemiological data as well as the lack of experimental reproducibility. Chronic inhalation of hair lacquers may, however, be responsible for bronchial irritative manifestations and obstruction of the small airways, in particular in hairdressers. Increase in the relative risk of bronchopulmonary carcinoma has not been proven. PMID:3912911

Ameille, J; Pages, M G; Capron, F; Proteau, J; Rochemaure, J

1985-01-01

19

Choroidal Thickness and Biometric Markers for the Screening of Lacquer Cracks in Patients with High Myopia  

PubMed Central

Objectives Validation of choroidal thickness and other biometrics measured by spectral domain optical coherence tomography (SD-OCT) in predicting lacquer cracks formation in highly myopic eyes. Methods Patients with a refractive error worse than ?8 diopters and moderate myopic maculopathy were recruited into two groups based on the presence or absence of lacquer cracks (36 eyes without and 33 eyes with lacquer cracks). Choroidal thickness, refractive error, and axial length were measured and subjected to receiver operating characteristic curve analysis to identify the optimal cutoff values at predicting lacquer crack formation. The width of the retinal pigment epithelium (RPE), RPE to the inner segment/outer segment line, RPE to the external limiting membrane were also measured and compared to the subfoveal choroidal thickness to assess their relationships as potential markers of lacquer crack formation. Results Lacquer crack is associated with decreased choroidal thickness, lower best-corrected visual acuity, longer axial length and higher refractive errors. Choroidal thickness has the strongest association with lacquer crack formation versus axial length and refractive error. In eyes with lacquer cracks, stellate lacquer cracks are associated with thinner choroidal thickness compared to eyes with linear lacquer cracks. Subfoveal choroidal thickness less than the width of the retinal pigment epithelium to the inner segment/outer segment line is also associated with lacquer crack formation (sensitivity 78.8%, specificity 88.3%, and accuracy 81.2%). Conclusions This study suggests that choroidal thickness and other SD-OCT measurements could be employed clinically to predict the development and severity of lacquer cracks in patients with high myopia.

Wang, Nan-Kai; Lai, Chi-Chun; Chou, Chai Lin; Chen, Yen-Po; Chuang, Lan-Hsin; Chao, An-Ning; Tseng, Hsiao-Jung; Chang, Chee-Jen; Wu, Wei-Chi; Chen, Kuan-Jen; Tsang, Stephen H.

2013-01-01

20

Separation of lacquer polysaccharides and interaction with poly-l-lysine.  

PubMed

A naturally occurring acidic lacquer polysaccharide with glucuronic acid at the terminals of the complex branches has specific biological activities including promotion of blood coagulation and antitumor activities. The polysaccharide has two molecular weight fractions M¯n=10×10(4) and M¯n=3.0×10(4). In the present work, two pure fractions were isolated for the first time by Sephadex G-100 column chromatography. Then, each fraction was treated with diluted alkaline solution to decrease the molecular weights to M¯n=3.0×10(4) and M¯n=1.4×10(4), respectively. The NMR and IR spectra and specific rotations of the fractionated and original lacquer polysaccharides were almost identical, suggesting that the lacquer polysaccharides are an associated structure with several low molecular weight polysaccharides of M¯n=1.4×10(4). Interactions between each lacquer polysaccharide and poly-l-lysine, a model compound of proteins and peptides with positively-charged amino groups, were investigated by surface plasmon resonance (SPR) to elucidate the biological mechanism. The apparent dissociation-rate (kd), association-rate (ka), and dissociation constant (KD) obtained by SPR indicate that the lacquer polysaccharides had weaker interactions with poly-l-lysine than sulfated polysaccharides and that the interaction depended on the molecular weight. These SPR results suggest that the specific biological activities of lacquer polysaccharides originate from electrostatic interaction. PMID:23987344

Bai, Yuting; Yoshida, Takashi

2013-05-25

21

Three new triterpenes from the roots of Rhus javanica L. var. roxburghiana.  

PubMed

Three new triterpenes, lantabetulal (1), lantanolal (2), and lantanolol (3) along with lantabetulic acid (4) and lantanolic acid (5) were isolated from the roots of Rhus javanica L. var. roxburghiana. The structural assignments of all these compounds were carried out by their spectroscopic analysis. PMID:18636383

Chiu, Chung-Liang; Lee, Tzong-Huei; Shao, Yi-Yuan; Kuo, Yueh-Hsiung

22

A Leaflet of Rhus toxicodendroides, a Fossil Plant from the Los Ahuehuetes Locality, Puebla, Mexico  

NSDL National Science Digital Library

A leaflet of Rhus toxicodendroides, a fossil plant from the Los Ahuehuetes locality, Puebla, Mexico, a center of diversity for the Anacardiaceae since the Oligocene, suggesting that the area was important for the radiation and diversification for some lineages within the family.

Hector Hernández Campos

2004-03-09

23

Comparative physiology of burned and unburned Rhus laurina after chaparral wildfire  

Microsoft Academic Search

Laurel Sumac (Rhus laurina) is a dominant member of the coastal chaparral community of southern California that survives periodic burning by wildfires by resprouting from a lignotuber (root crown). We investigated the physiological basis for resprouting by comparing shoot elongation, leaf nitrogen content, tissue water status, leaf conductance to water vapor diffusion, and photosynthetic rates of post-fire R. laurina to

J. DeSouza; P. A. Silka; S. D. Davis

1986-01-01

24

Antidiabetic properties of the ethanolic extract of Rhus coriaria fruits in rats  

PubMed Central

Background and the purpose of the study Fruits of Rhus coriaria L. (Anacardiaceae) are traditionally used as a table spice in Iran and are highly recommended for diabetic patients. The purpose of this study was to determine the antidiabetic properties of the ethanolic extract of Rhus coriaria fruits and also its mechanisms of action. Methods The effects of ethanolic extract of Rhus coriaria fruits were measured on blood glucose, lipids and antioxidant enzymes by commercial kits. mRNA levels of insulin (INS) and glucose transporter type-4 (GLUT-4) genes were investigated by RT-PCR (Reverse transcription- polymerase chain reaction) technique. Moreover, its effects on intestinal a-glucosidases was measured using an in vitro method. Results and Conclusion Following a single dose administration of the extract it was found that extract could significantly reduce postprandial blood glucose by 24% (at 5 hrs). In the long term experiment, on the day of 21, postprandial blood glucose (PBG) was found to be significantly lower (by 26%) compared to diabetic control group. The plant extract raised markedly serum high-density lipoprotein (HDL) by 34% and also reduced low-density lipoprotein (HDL) by 32%. Also it had noticeable antioxidant effects by elevating superoxide dismutase (SOD) and catalase(CAT) activities by 46% and 77%, respectively. However it did not show a strong effect on glutathione peroxidase (GPX) activity. The extract inhibited maltase and sucrase activities by 44% and 27%, respectively. However it made no changes in the transcript levels of INS and GLUT-4 genes. It can be concluded that constituents of Rhus coriaria fruits have effective components which can be utilized as useful herb for alleviation of diabetes complications.

Mohammadi, S.; Montasser Kouhsari, S; Monavar Feshani, A

2010-01-01

25

Hypoglycaemic activity of two spices extracts: Rhus coriaria L. and Bunium persicum Boiss  

Microsoft Academic Search

The hypoglycaemic efficacy of sumac (Rhus coriaria L.) and black cumin (Bunium persicum Boiss) extracts were investigated through inhibition of a glycoside hydrolase: ?-amylase. On the basis of our result ethyl acetate extract of sumac may have interest in the treatment and prevention of hyperglycaemia, diabetes and obesity, with an IC50 value of 28.7?µg?mL. §Statti Giancarlo and Loizzo Monica Rosa

Statti Giancarlo; Loizzo Monica Rosa; Farsad Nadjafi; Menichini Francesco

2006-01-01

26

High Speed Liquid Chromatographic Determination of Total Aromatics in Enamel and Lacquer Solvents.  

ERIC Educational Resources Information Center

|Aromatic solvents possess the strongest solvency of the hydrogen types, but various air pollution control districts have established maximum limits on the amount that may be present in organic coatings. In the proposed procedure, high efficiency liquid chromatography is used to determine total aromatics in enamels and lacquer thinners, their…

Esposito, G. G.

27

Ciclopirox nail lacquer topical solution 8% in the treatment of toenail onychomycosis  

Microsoft Academic Search

Background: Onychomycosis is a relatively common condition affecting toenails more than fingernails. It is caused predominantly by dermatophytes. Onychomycosis can cause pain and discomfort and has the potential to be a source of morbidity. Objective: We evaluated the efficacy and safety of ciclopirox nail lacquer solution 8% used to treat onychomycosis of the toe in the United States and in

Aditya K. Gupta; Philip Fleckman; Robert Baran

2000-01-01

28

Bark Constituents from Mushroom-detoxified Rhus verniciflua Suppress Kainic Acid-induced Neuronal Cell Death in Mouse Hippocampus  

PubMed Central

Urushinol, a plant allergen, has significantly restricted the medical application of Rhus verniciflua, although it has been reported to possess a wide variety of biological activities such as anti-inflammatory, antioxidant, and anti-cancer actions. To reduce the urushinol content while maintaining the beneficial biological activities, mushroom-mediated fermentation of Rhus verniciflua was carried out and this method resulted in significantly attenuated allergenicity [1]. In the present study, to examine the neuroprotective properties of mushroom-fermented stem bark of Rhus verniciflua, two constituents were isolated from mushroom-fermented bark and their neuroprotective properties were examined in a mouse model of kainic acid (KA)-induced excitotoxicity. KA resulted in significant apoptotic neuronal cell death in the CA3 region of mouse hippocampus. However, seven daily administrations of RVH-1 or RVH-2 prior to KA injection significantly attenuated KA-induced pyramidal neuronal cell death in the CA3 region. Furthermore, pretreatment with RVH-1 and RVH-2 also suppressed KA-induced microglial activation in the mouse hippocampus. The present study demonstrates that RVH-1 and RVH-2 isolated from Rhus verniciflua and detoxified using mushroom species possess neuroprotective properties against KA-induced excitotoxicity. This leads to the possibility that detoxified Rhus verniciflua can be a valuable asset in herbal medicine.

Byun, Jong-Seon; Han, Yoon Hee; Hong, Sung-Jun; Hwang, Sung-Mi; Kwon, Yong-Soo; Lee, Hee Jae; Kim, Sung-Soo; Kim, Myong-Jo

2010-01-01

29

Imaging Stokes polarimeter by dual rotating retarder and analyzer and its application of evaluation of Japanese lacquer  

NASA Astrophysics Data System (ADS)

Lacquer crafts are distributed over Southeast Asia from the East Asia such as China and Korea, Vietnam, Myanmar including Japan. Especially, a Japanese lacquer is well-known traditional crafts. Its color is jet black but people feel different texture because it is made by complicated and multi step manufacturing process such as coating and polishing with different materials. In this report, we focus polarization properties of surface structures on black Japanese lacquer. All states of polarization can be expressed Stokes parameters, which are consisted on four elements as s0 to s3. These parameters are effective for the evaluation of the state of polarization. The polarization information of surface structure of Japanese lacquer can be visualized by using an imaging Stokes polarimeter by dual rotating retarder and analyzer. It is possible to evaluate surface character by comparing the degree of polarization. It is effective to evaluate the surface by using the polarization information.

Mizutani, Ryota; Ishikawa, Tomoharu; Ayama, Miyoshi; Otani, Yukitoshi

2012-11-01

30

Historical biogeography of Eastern Asian-Eastern North American disjunct Melaphidina aphids (Hemiptera: Aphididae: Eriosomatinae) on Rhus hosts (Anacardiaceae).  

PubMed

Intercontinental biotic disjunctions have been documented and analyzed in numerous Holarctic taxa. Patterns previously synthesized for animals compared to plants suggest that the timing of animal disjunctions are mostly Early Tertiary and were generated by migration and vicariance events occurring in the North Atlantic, while plant disjunctions are mostly Mid-Late Tertiary and imply migration and vicariance over Beringia. Melaphidina aphids (Hemiptera: Aphididae: Fordini) exhibit host-alternating life cycles comprising an obligate seasonal shift between Rhus subgenus Rhus species (Anacardiaceae) and mosses (Bryophyta). Similar to their Rhus hosts, melaphidines are distributed disjunctly between Eastern Asia and Eastern North America. We examined evolutionary relationships within Melaphidina to determine the position of the North American lineage, date its divergence from Asian relatives, and compare these results to a previous historical biogeographic study of Rhus. We sampled nine species and three subspecies representing all six genera of Melaphidina. Data included sequences of mitochondrial cytochrome c oxidase subunits I and II+leucine tRNA, cytochrome b, and nuclear elongation factor 1? genes. Phylogenetic analyses (Bayesian, maximum-likelihood, parsimony) of the combined data (3282bp) supported the monophyly of all genera except Nurudea and Schlechtendalia, due to the position of N. ibofushi. While the exact position of the North American Melaphis was not well resolved, there was high support for a derived position within Asian taxa. The divergence of Melaphis from Asian relatives centered on the Eocene-Oligocene boundary (?33-35Ma), which coincides with closure of Beringian Land Bridge I. This also corresponded to the Asian-North American disjunction previously estimated for subgenus Rhus spp. We suggest the late-Eocene Bering Land Bridge as the most likely migration route for Melaphis ancestors, as was also hypothesized for North American Rhus ancestors. Results for the Melaphidina disjunction depart from the modal pattern in animal lineages, and present a case where insect and host-plant taxa apparently responded similarly to Tertiary climate change. PMID:23973894

Ren, Zhumei; Zhong, Yang; Kurosu, Utako; Aoki, Shigeyuki; Ma, Enbo; von Dohlen, Carol D; Wen, Jun

2013-08-21

31

Contradictory results of the UVCON and saline immersion tests regarding the evaluation of some inhibitor\\/lacquer combinations on galvanised coatings  

Microsoft Academic Search

The effectiveness of inhibitors “with chromate” and “with phosphate” that accompany lacquer films applied on hot galvanised steel specimens has been studied using continuous immersion tests in 3% NaCl and UVCON tests in a climate cabinet. These tests, in combination with the EIS and XPS techniques, show that the behaviour of the inhibitor\\/lacquer system is dependent on the type of

S Feliu; V Barranco

2004-01-01

32

Diamond-turned lacquer-coated soft x-ray telescope mirrors.  

PubMed

X-ray astronomy has reached sufficient maturity to demand at least moderate angular resolution lightgathering telescopes to accompany detector development. Keeping the cost of such telescopes within the budget of low-cost flight opportunities such as sounding rockets and SPARTAN missions is a substantial challenge. We have developed a program of precision diamond mirror turning, mechanical polishing, lacquer coating, and metal deposition which produces x-ray telescopes with minute of arc angular resolution at moderate cost. We describe the process and report calibration results for a 80 cm (31.4 in.) diam Wolter I telescope flown aboard an Aries sounding rocket. PMID:20531592

Nousek, J A; Garmire, G P; Pipetti, R J; Burrows, D N; Ku, W H; Lum, K S

1988-04-15

33

Correlation between antibutyrylcholinesterasic and antioxidant activities of three aqueous extracts from Tunisian Rhus pentaphyllum  

PubMed Central

For centuries, plants have been used in traditional medicines and there has been recent interest in the chemopreventive properties of compounds derived from plants. In the present study, we investigated the antibutyrylcholinestrasic (anti-BuChE) and antioxidant (against some free radicals) activities of extracts from Rhus pentaphyllum. Aqueous extracts were prepared from powdered R. pentaphyllum roots, leaves and seeds and characterized for the presence of tannins, flavonoids and coumarins. Seeds aqueous extract contained the highest quantities of both flavonoids and tannins (21.12% and 17.45% respectively). In the same way, seeds extracts displayed remarkable inhibition against BuChE over 95%, at 100 ?g/ml and with IC50 0.74 ?g/ml. In addition, compared to leaves and roots extracts, seeds aqueous extract revealed relatively strong antiradical activity towards the ABTS.+ (IC50 = 0.25 ?g/ml) and DPPH (IC50 = 2.71 ?g/ml) free radicals and decreased significantly the reactive oxygen species such O2.- (IC50 = 2.9 ?g/ml) formation evaluated by the non-enzymatic generating O2.- system (Nitroblue tetrazolium/riboflavine). These data suggest that the anti-BuChE activities mechanism of these extracts occurs through a free radical scavenging capacities. The present study indicates that extracts of Rhus pentaphyllum leaves, seeds and roots are a significant source of compounds, such as tannins, flavonoids and coumarins, with anti-BuChE and antioxidant activities, and thus may be useful for chemoprevention.

2011-01-01

34

Polymer films releasing nisin and\\/or natamycin from polyvinyldichloride lacquer coating: Nisin and natamycin migration, efficiency in cheese packaging  

Microsoft Academic Search

Polyethylene films coated by commercially available polyvinyldichloride (PVdC) as well as nitrocellulose (NC) lacquer with addition of natamycin preparation Delvocid® (16.7% w\\/w of natamycin in lacquer) were studied at 6 and 23°C to determine the preservative migration into distilled water. The films released natamycin at maximal level 2.34±0.32mg\\/dm2. The diffusion coefficient of 0.79×10?10±0.29×10?10cm2\\/s and 1.03×10?10±0.17×10?10cm2\\/s was determined for natamycin transport

Kristýna Hanušová; Monika Š?astná; Lenka Votavová; Kamila Klaudisová; Jaroslav Dobiáš; Michal Vold?ich; Miroslav Marek

2010-01-01

35

Loceryl nail lacquer--realization of a new galenical approach to onychomycosis therapy.  

PubMed

Loceryl nail lacquer was developed to provide the effective antifungal drug, amorolfine, in a once-weekly dosage regimen combined with a convenient mode of application. Traditional formulations such as creams and nail solutions do not fulfil these requirements because they are wiped or washed off very rapidly. Amorolfine nail lacquer builds a non-water-soluble film on the nail plate, and this film remains in place for 1 week. The film contains a high concentration of amorolfine and forms a depot from which the drug is delivered and which allows the drug to permeate the nail plate. The film-forming polymer and the solvent were optimized for drug release, stability, and convenience of application (drying time, no gloss, transparency). In preclinical development, porcine hoof horn was used as a screening model to differentiate between formulations and dosage strengths with respect to the penetration rate. A high drug concentration of 11.72 micrograms/specimen (10 mm in diameter) was reached in the hoof horn after 6 h, increasing to 39.5 micrograms/specimen within 7 days, the maximum duration of the investigation. The drug concentration achieved was far above its minimum inhibitory concentration. Furthermore, the penetration model clearly indicated that amorolfine crossed the horn barrier and was found in the moistened gauze which simulated the nail bed. After a 7-day penetration period, 1.8% of the applied dose (500 micrograms) was available under the nail. PMID:1458660

Pittrof, F; Gerhards, J; Erni, W; Klecak, G

1992-09-01

36

The regulation of inflammatory cytokine secretion in macrophage cell line by the chemical constituents of Rhus sylvestris  

Microsoft Academic Search

In our preliminary screening study on the anti-inflammatory activity, eight triterpenes, one sterol, and one chalcone were isolated from the CH2Cl2-soluble extract of the stems and leaves of Rhus sylvestris Siebold and Zucc (Anacardiaceae). On the basis of their spectroscopic data, these compounds were identified as 10?-cucurbitadienol (1), glut-5-en-3-ol (2), ?-amyrin acetate (3), ?-amyrin (4) and lupeol (5), cycloart-24-en-3-one (6),

Yan Ding; Huu Tung Nguyen; Sung In Kim; Ha Won Kim; Young Ho Kim

2009-01-01

37

Efficacy of Injections with Disci\\/Rhus Toxicodendron Compositum for Chronic Low Back Pain – A Randomized Placebo-Controlled Trial  

Microsoft Academic Search

BackgroundThe effectiveness of injection therapy for low-back pain is still debatable. We compared the efficacy of local injections of the homeopathic preparation Disci\\/Rhus toxicodendron compositum (verum) with placebo injections and with no treatment in patients with chronic low back pain.Methodology\\/Principal FindingsIn a randomized controlled partly double blind multicenter trial patients with chronic low back pain from 9 German outpatient clinics

Daniel Pach; Benno Brinkhaus; Stephanie Roll; Karl Wegscheider; Katja Icke; Stefan N. Willich; Claudia M. Witt

2011-01-01

38

Comparative efficacy and safety of amorolfine nail lacquer 5% in onychomycosis, once-weekly versus twice-weekly.  

PubMed

Amorolfine is a new topical antifungal of the phenylpropyl morpholine class which is highly active both in vitro and in vivo against yeasts, dermatophytes and moulds responsible for superficial fungal infections. Human pharmacological studies have established that amorolfine has a persistent antifungal effect in the nail bed and in the skin without being systemically absorbed. This has been confirmed by clinical work showing that amorolfine is effective in treating dermatomycoses and onychomycoses when administered as cream or nail lacquer. It is ineffective when given orally for systemic mycoses or bacterial infections in animals. In earlier studies a 5% concentration of amorolfine nail lacquer was found to produce a better cure rate in onychomycosis than a lower concentration of 2%. From data available on the penetration of amorolfine and on the persistence of mycologically relevant tissue concentrations, it appeared likely that once- or twice-weekly application of nail lacquer should suffice to produce a satisfactory therapeutic effect in onychomycosis. The aim of this investigation was to assess the efficacy and tolerability of 5% amorolfine nail lacquer given once versus twice weekly to patients with onychomycosis of finger nails and toe nails. PMID:1458665

Reinel, D; Clarke, C

1992-09-01

39

Extract of Rhus verniciflua Bark Suppresses 2,4-Dinitrofluorobenzene-Induced Allergic Contact Dermatitis.  

PubMed

Rhus verniciflua Stokes (RV) has traditionally been used as a food supplement and a traditional herbal medicine for centuries in Korea. Recent studies suggest that RV has potent antioxidative, antitumor, and anti-inflammatory properties. In this study, the anti-inflammatory effects of RV from mice sensitized with 2,4-dinitrofluorobenzene (DNFB) and activated macrophages were investigated. The results showed that RV reduced ear swelling and hyperplasia of ear tissue as well as an increase in vascular permeability, which are characteristics of allergic contact dermatitis (ACD) with evident histomorphological changes in epidermis and dermis. Decreased numbers of infiltrated mast cells were seen in RV extract treated group, using toluidine blue staining. RV extract significantly regulates the expression of inducible nitric oxide synthase (iNOS) at the translational level in activated macrophages. Furthermore, RV extract and its active compound, fisetin, attenuated the level of tumor necrosis factor- ? (TNF- ? ) and interleukin 6 (IL-6) mRNA in LPS-stimulated macrophages. Anti-ACD effect of RV extract may be due to the suppression of iNOS and proinflammatory cytokines which might be mediated via the NF ? B signaling pathways. Collectively, RV extract has potential for alleviating ACD-like symptoms induced by DNFB in the mouse. PMID:23710240

Park, Dong Ki; Lee, Yang Gi; Park, Hye-Jin

2013-04-24

40

Extract of Rhus verniciflua Bark Suppresses 2,4-Dinitrofluorobenzene-Induced Allergic Contact Dermatitis  

PubMed Central

Rhus verniciflua Stokes (RV) has traditionally been used as a food supplement and a traditional herbal medicine for centuries in Korea. Recent studies suggest that RV has potent antioxidative, antitumor, and anti-inflammatory properties. In this study, the anti-inflammatory effects of RV from mice sensitized with 2,4-dinitrofluorobenzene (DNFB) and activated macrophages were investigated. The results showed that RV reduced ear swelling and hyperplasia of ear tissue as well as an increase in vascular permeability, which are characteristics of allergic contact dermatitis (ACD) with evident histomorphological changes in epidermis and dermis. Decreased numbers of infiltrated mast cells were seen in RV extract treated group, using toluidine blue staining. RV extract significantly regulates the expression of inducible nitric oxide synthase (iNOS) at the translational level in activated macrophages. Furthermore, RV extract and its active compound, fisetin, attenuated the level of tumor necrosis factor-? (TNF-?) and interleukin 6 (IL-6) mRNA in LPS-stimulated macrophages. Anti-ACD effect of RV extract may be due to the suppression of iNOS and proinflammatory cytokines which might be mediated via the NF?B signaling pathways. Collectively, RV extract has potential for alleviating ACD-like symptoms induced by DNFB in the mouse.

Park, Dong Ki; Lee, Yang Gi; Park, Hye-Jin

2013-01-01

41

Topical treatment of onychomycosis with amorolfine 5% nail lacquer: comparative efficacy and tolerability of once and twice weekly use.  

PubMed

456 patients with onychomycosis were treated once or twice weekly for up to 6 months with amorolfine 5% nail lacquer in an open, randomized study. The patients were examined at monthly intervals during treatment and followed-up 1 and 3 months after completion of treatment. Slightly better cure rates were achieved with twice weekly use than with once weekly use (overall cure rates 54.2 vs. 46.0%, p = 0.4). An overall cure or improvement was achieved in 74 and 68% of patients receiving twice- and once-weekly treatment, respectively. The mycological cure rate was 76.1% for twice-weekly treatment and 70.6% for once-weekly treatment. The nail lacquer was extremely well tolerated; 4 out of 456 patients reported mild local irritation. Plasma levels of amorolfine were determined in 19 patients and found to be below the detection limit of 0.5 ng/ml in all cases. PMID:1532336

Reinel, D

1992-01-01

42

Anti-HIV-1 activity, protease inhibition and safety profile of extracts prepared from Rhus parviflora  

PubMed Central

Background In the present study, extracts prepared from the leaves of Rhus parviflora Roxb. (Anacardiaceae) were evaluated for their anti-HIV activity, which have been traditionally used for the treatment of neurological disorders such as anxiety, insomnia and epilepsy. Methods Aqueous and 50% ethanolic extracts prepared from leaves of the plant were tested for their cytotoxicity and anti-HIV property using reporter gene based assays as well as human peripheral blood lymphocytes (PBLs). Further these extracts were evaluated for their ability to inhibit HIV-1 reverse transcriptase (RT) and protease activity. Safety profile of the extracts was determined on viability of Lactobacillus sp., secretion of pro-inflammatory cytokines by vaginal keratinocytes and transepithelial resistance. Results Both aqueous (IC50?=?15 ?g/ml) and 50% ethanolic (IC50?=?26 ?g/ml) extracts prepared from leaves of R. parviflora showed anti-HIV activity in TZM-bl cells wherein the virus was treated with the extracts prior to infection. Further, both the extracts also inhibited virus load in HIV infected CEM-GFP cells and human PBLs. The anti-HIV activity is mediated through inhibition of HIV-1 protease activity. Both the extracts did not disturb the integrity of monolayer formed by intestinal epithelial Caco-2 cells. The extracts when tested up to 100 ?g/ml did not significantly reduce the viability of L. plantarum, L. fermentum, L. rhamnosus and L. casei. The extracts (100 ?g/ml) did not reveal any cytotoxic effect on vaginal keratinocytes (Vk2/E6E7). Levels of pro-inflammatory cytokines secreted by Vk2/E6E7 cells treated with both the plant extracts were within the non-inflammatory range. Conclusions The studies reported herein showed in vitro anti-HIV activity and preliminary safety profile of the extracts prepared from the leaves of R. parviflora.

2013-01-01

43

Anti-inflammatory and anti-nociceptive effects of the extract from Kalopanax pictus, Pueraria thunbergiana and Rhus verniciflua.  

PubMed

The combined extracts obtained from three Chinese herb medicine, Kalopanax pictus, Pueraria thunbergiana and Rhus verniciflua, have been used as therapeutics for diabetes mellitus in Korea. In the present study, we have investigated their possible anti-inflammatory effects by comparing the potency of individual extracts with that of the combined extracts. An individual water extract prepared from Kalopanax pictus, Pueraria thunbergiana, and Rhus verniciflua was named K-1, P-1, and R-1, respectively. Simultaneously, we also prepared the combined extracts from above three plant materials by identical methods and named KPR-1. These four extracts were further fractionated into the EtOAc extracts, and these were designated as K-2, P-2, R-2, and KPR-2, respectively. These eight samples were subjected to the nitrite assays in LPS-induced macrophage 264.7 cells. KPR-2 exhibited the most pronounced effect on the inhibition of NO production among all the extracts. KPR-2 also significantly decreased PGE2, and TNF-alpha release. In addition, KPR-2 showed in vivo anti-inflammatory activity against acute paw edema induced by carrageenan in rats. When analgesic activity was measured by the acetic acid-induced abdominal constriction and hot plate test, KPR-2 showed a dose-dependent inhibition in animal models. These results suggested that the mixture extract and successive fractionation could lead to the better use of anti-inflammatory medicinal crude drugs. PMID:15261979

Kim, In-Tae; Park, Young-Mi; Shin, Kyung-Min; Ha, Joohun; Choi, Jongwon; Jung, Hyun-Ju; Park, Hee-Juhn; Lee, Kyung-Tae

2004-09-01

44

Quality control of commercial Mediterranean oregano: Development of SCAR markers for the detection of the adulterants Cistus incanus L., Rubus caesius L. and Rhus coriaria L  

Microsoft Academic Search

A recent pharmacognostic survey showed a frequent adulteration of commercial Mediterranean oregano with dried plants having a similar silvery gray color (Rhus coriaria L., Cistus spp. and Rubus spp.). If performed by skilled adulterators, the detection of this practice relies almost completely on pharmacognostic assays which are extremely laborious and time consuming, especially when multiple batches of oregano have to

Matteo Marieschi; Anna Torelli; Ferruccio Poli; Alberto Bianchi; Renato Bruni

2010-01-01

45

PROCESSING, PRODUCTS, AND FOOD SAFETY The Effect of Water Extract of Sumac (Rhus coriaria L.) and Lactic Acid on Decontamination and Shelf Life of Raw Broiler Wings  

Microsoft Academic Search

In an attempt to improve the bacteriologi- cal quality and refrigerated shelf life of broiler meat, 10- min surface wash treatments with sterile distilled water (DW), 8% (wt\\/vol) water extract of sumac (Rhus coriaria L.) fruits (WES), and 2% (vol\\/vol) lactic acid (LA) were compared by using a broiler wing model. The aerobic plate counts (log10 cfu\\/g) of psychrotrophs, mesophilic

M. Gulmez; N. Oral; L. Vatansever

46

Phenolic-rich fraction from Rhus verniciflua Stokes (RVS) suppress inflammatory response via NF-?B and JNK pathway in lipopolysaccharide-induced RAW 264.7 macrophages  

Microsoft Academic Search

The effects of phenolic-rich fraction (PRF) from Rhus verniciflua Stokes (Anacardiaceae) on the activities of cellular signaling molecules that mediate inflammatory responses in LPS-induced RAW 264.7 macrophages were investigated. At various concentrations of PRF significantly inhibited NO, PGE2 and TNF-? production in LPS-induced RAW 264.7 macrophage cells. The PRF also significantly inhibited iNOS and COX-2 protein expression in LPS-induced RAW

Chang Hwa Jung; Ji Hye Kim; Myung Hee Hong; Ho Moon Seog; Seong Hoon Oh; Pan Jae Lee; Gyung Jun Kim; Hyung Min Kim; Jae Young Um; Seong-Gyu Ko

2007-01-01

47

Comparison of quantitative analysis techniques for the determination of heat seal lacquer layers on aluminum blister foils.  

PubMed

For decades a gravimetric method has been common standard for the determination of heat seal lacquers on aluminum blister foils. With the availability of appropriate techniques such as interferometric, infrared reflection absorption spectroscopic (IRRAS), beta backscatter, impedance spectroscopic and eddy current techniques respectively, more efficient determinations can be foreseen which are subject of the present communication. The different methods were compared to each other regarding parameters required for validation of analytical procedures according to the ICH guidelines Q2 (R1) such as linearity, precision, accuracy, robustness and quantitation limits. The interferometric, IRRAS and beta backscatter techniques were well suitable for the measurements. Using these techniques novel procedures applicable for routine quality control of pharmaceutical packaging materials are suggested. PMID:20888412

Mühlfeld, Lukas; Langguth, Peter; Häusler, Heribert; Hagels, Hansjörg

2010-10-01

48

[Assessment of hearing impairment in workers exposed to mixtures of organic solvents in the paint and lacquer industry].  

PubMed

Clinical and experimental studies indicate a possible harmful effect of chemicals, especially organic solvents, on the hearing system. In combined exposure to noise and solvents, very common in industry, it is most likely that a synergetic action of these factors enhances the traumatising effect of exposure to noise. The aim of this study was to assess the incidence and the risk of hearing impairment in 117 paint and lacquer factory workers exposed to a mixture of organic solvents. An analysis of organic solvent mixtures reveals that xylene and ethyl acetate are their major components whose concentrations depend on individual workposts. The control group consisted of 76 workers exposed to noise exceeding, Threshold Limit Value and 125 healthy subjects exposed neither to noise nor to solvents in their occupational setting. Pure tone audiometry revealed the highest hearing thresholds in workers exposed to solvents, lower thresholds in those exposed to noise, and the lowest ones in the non-exposed individuals. Hearing loss was found in 30% of workers exposed to organic solvents, in 20% of noise-exposed subjects, and in only 6% of non-exposed subjects. The comparison of relative risk values also indicated significantly enhanced probability of hearing impairment in workers of the paint and lacquer factory (9.6; 3.2-25.6), which is even more strongly pronounced than in the group of subjects exposed to noise (4.2; 1.2-13.2). An analysis of hearing impairment risk in particular frequencies suggests that organic solvents may damage the inner ear in much greater extent than noise. The results of the study show that exposure to organic solvents may create a significant risk of hearing impairment. Therefore, further steps should be taken to include the exposed population into effective preventive programmes. PMID:10857071

Sliwi?ska-Kowalska, M; Zamys?owska-Szmytke, E; Koty?o, P; Weso?owski, W; Dudarewicz, A; Fiszer, M; Pawlaczyk-Luszczy?ska, M; Polita?ski, P; Kucharska, M; Bilski, B

2000-01-01

49

Efficacy of Injections with Disci/Rhus Toxicodendron Compositum for Chronic Low Back Pain - A Randomized Placebo-Controlled Trial  

PubMed Central

Background The effectiveness of injection therapy for low-back pain is still debatable. We compared the efficacy of local injections of the homeopathic preparation Disci/Rhus toxicodendron compositum (verum) with placebo injections and with no treatment in patients with chronic low back pain. Methodology/Principal Findings In a randomized controlled partly double blind multicenter trial patients with chronic low back pain from 9 German outpatient clinics were enrolled and randomly allocated in a 1?1?1 ratio to receive subcutaneous injections (verum or placebo) into painful sites on the lower back over 12 treatment sessions within eight weeks, or no treatment (rescue pain medication with paracetamol or NSAIDs). All trial personnel and participants were masked to treatment allocation. The primary outcome measure was the average pain intensity over the last seven days on a visual analogue scale (0–100 mm, 0?=?no pain, 100?=?worst imaginable pain) after eight weeks. Follow-up was 26 weeks. Primary analysis was by intention to treat. Between August 2007 and June 2008, 150 patients were randomly allocated to three groups (51 verum, 48 placebo and 51 no treatment). The mean baseline-adjusted low back pain intensity at week eight was: verum group 37.0 mm (97.5% CI 25.3;48.8), no treatment group 53.0 (41.8;64.2), and placebo group 41.8 (30.1;53.6). The verum was significantly superior to no treatment (P?=?0.001), but not to placebo (P?=?0.350). No significant side effects were reported. Conclusions/Significance The homeopathic preparation was not superior to placebo. Compared to no treatment injections resulted in significant and clinical relevant chronic back pain relief. Trial Registration ClinicalTrials.gov NCT00567736

Pach, Daniel; Brinkhaus, Benno; Roll, Stephanie; Wegscheider, Karl; Icke, Katja; Willich, Stefan N.; Witt, Claudia M.

2011-01-01

50

Analgesic, anti-inflammatory and hypoglycaemic effects of Rhus chirindensis (Baker F.) [Anacardiaceae] stem-bark aqueous extract in mice and rats.  

PubMed

In an attempt to scientifically evaluate some of the anecdotal, folkloric, ethnomedical uses of Rhus chirindensis Baker F. ('red currant'), the present study was undertaken to investigate the analgesic, anti-inflammatory and hypoglycaemic effects of the plant's stem-bark aqueous extract (RCE) in mice and rats. The analgesic effect of RCE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while its anti-inflammatory and hypoglycaemic effects were investigated in rats, using fresh egg albumin-induced pedal oedema, and streptozotocin (STZ)-induced diabetes mellitus animal models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. RCE (50-800 mg/kg i.p.) produced dose-dependent, significant (P<0.05-0.001) analgesic effects against thermally- and chemically-induced nociceptive pain in mice. The plant's extract (RCE, 50-800 mg/kg p.o.) also significantly (P<0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (P<0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic (hyperglycaemic) rats. The flavonoids, triterpenoids and other chemical compounds present in RCE are speculated to account for the observed pharmacological effects of the plant's extract in the experimental animal paradigms used. The findings of this experimental animal study indicate that Rhus chirindensis stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties; and thus lend pharmacological credence to the anecdotal, folkloric, ethnomedical uses of the plant in the treatment and/or management of painful, arthritic, inflammatory conditions, as well as in the management and/or control of type 2 diabetes mellitus in some rural communities of South Africa. PMID:17689903

Ojewole, John A O

2007-07-07

51

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

52

Rhus copallinum L.  

Treesearch

Wildland shrubs of the United States and its Territories: thamnic descriptions: ... in abandoned fields, along roadsides, in glades and open woods, and in waste areas. ... It is not, however, a preferred food and is considered a poor to moderately ...

53

Rhus (Toxicodendron) dermatitis.  

PubMed

This article reviews the current fund of knowledge on poison ivy, poison oak, and poison sumac dermatitis. It is intended as a global summary to provide the primary care provider with the required information and sources for more esoteric academic pursuits. Toxicodendron characteristics, morphology, and biology are reviewed. The overall medical impact is delineated as well as the clinical manifestations, pathophysiology, prevention, and treatment. Historical perspectives are mentioned throughout, as are future trends in research. PMID:10815057

Tanner, T L

2000-06-01

54

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

55

Growing Tree  

NSDL National Science Digital Library

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

Sedgewick, Bob; Wayne, Kevin; Sanders, Corey

56

Stabilization of erythrocytes against oxidative and hypotonic stress by tannins isolated from sumac leaves (Rhus typhina L.) and grape seeds (Vitis vinifera L.).  

PubMed

Erythrocytes are constantly exposed to ROS due to their function in the organism. High tension of oxygen, presence of hemoglobin iron and high concentration of polyunsaturated fatty acids in membrane make erythrocytes especially susceptible to oxidative stress. A comparison of the antioxidant activities of polyphenol-rich plant extracts containing hydrolysable tannins from sumac leaves (Rhus typhina L.) and condensed tannins from grape seeds (Vitis vinifera L.) showed that at the 5-50 ?g/ml concentration range they reduced to the same extent hemolysis and glutathione, lipid and hemoglobin oxidation induced by erythrocyte treatment with 400 ?M ONOO(-) or 1 mM HClO. However, extract (condensed tannins) from grape seeds in comparison with extract (hydrolysable tannins) from sumac leaves stabilized erythrocytes in hypotonic NaCl solutions weakly. Our data indicate that both hydrolysable and condensed tannins significantly decrease the fluidity of the surface of erythrocyte membranes but the effect of hydrolysable ones was more profound. In conclusion, our results indicate that extracts from sumac leaves (hydrolysable tannins) and grape seeds (condensed tannins) are very effective protectors against oxidative damage in erythrocytes. PMID:22491984

Olchowik, Ewa; Lotkowski, Karol; Mavlyanov, Saidmukhtar; Abdullajanova, Nodira; Ionov, Maksim; Bryszewska, Maria; Zamaraeva, Maria

2012-04-10

57

Protective Effect of Detoxified Rhus verniciflua Stokes on Human Keratinocytes and Dermal Fibroblasts against Oxidative Stress and Identification of the Bioactive Phenolics.  

PubMed

Oxidative stress due to the over-production of reactive oxygen species (ROS) is associated with human skin aging. This study was designed to identify the bioactive phenolics in detoxified Rhus verniciflua Stokes (DRVS) that may protect human skin against oxidative stress. Under oxidative stress caused by H2O2, the 40% (v/v) aqueous methanol extract of DRVS protected human keratinocytes in a dose-dependent manner. The expression of matrix metalloproteinase-1 (MMP-1) was also inhibited by the DRVS extract in human dermal fibroblasts-neonatal cells exposed to ultraviolet A. The major bioactive phenolics of DRVS were tentatively identified by LC/Q-TOF-ESI-MS/MS, and included gallic acid, 2-(ethoxymethoxy)-3-hydroxyphenol, fustin, a fustin isomer, tetragalloyl glucose, pentagalloyl glucose, fisetin, sulfuretin, a sulfuretin isomer, and butein. The results suggest that a DRVS extract may be effective in slowing skin aging through its antioxidative properties and by down-regulating MMP-1 expression. Further studies are needed to examine whether this effect would be mediated by the phenolics identified in this study. PMID:23924730

Liu, Chun-Shan; Nam, Tae-Gyu; Han, Min-Woo; Ahn, Soo-Mi; Choi, Han Seok; Kim, Tae Young; Chun, Ock K; Koo, Sung I; Kim, Dae-Ok

2013-08-07

58

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.

59

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

60

Greenhouse trees  

SciTech Connect

Michigan State University has been conducting research on growth control of woody plants with emphasis on commercial plantations. The objective was to develop the optimum levels for the major factors that affect tree seedling growth and development so that high quality plants can be produced for a specific use. This article describes the accelerated-optimal-growth (AOG) concept, describes precautions to take in its application, and shows ways to maximize the potential of AOG for producing ornamental trees. Factors considered were container growing system; protective culture including light, temperature, mineral nutrients, water, carbon dioxide, growth regulators, mycorrhizae, growing media, competition, and pests; size of seedlings; and acclamation. 1 table. (DP)

Hanover, J.W.; Hart, J.W.

1980-05-09

61

Anti-oxidant and natural killer cell activity of Korean red ginseng (Panax ginseng) and urushiol (Rhus vernicifera Stokes) on non-alcoholic fatty liver disease of rat.  

PubMed

Anti-oxidative and immunologic effects of the Korea red ginseng (KRG; Panax ginseng) and urushiol (Rhus vernicifera Stokes) on non-alcoholic fatty liver disease (NAFLD) were evaluated. Forty-five rats (five Long-Evans Tokushima Otsuka and 40 Otsuka Long-Evans Tokushima Fatty [OLETF] rats) received chew diets for 10months; after this period. The OLETF rats were divided into the following four groups according to diet for 2months: NAFLD (chew), KRG (chew+KRG [200mg/kg/day]), urushiol (chew+urushiol [0.5mg/kg/day]), and ursodeoxycholic acid (UDCA) (chew+UDCA [15mg/kg/day]) groups. Liver function, lipid profiles and anti-oxidant activity of liver and serum, natural killer (NK) cell activity, and pathology were compared. In KRG and urushiol groups, the level of serum triglyceride ([302.0±70.4 and 275.2±63.8] vs. 527.7±153.3mg/dL) were lower compared with that of NAFLD group (p<0.05). The levels of HDL-cholesterol (liver tissue: [4.8±0.2 and 4.8±0.5] vs. 4.2±0.2mg/g) and NK cell activity ([3485±910 and 3559±910] vs. 2486±619 counts) were significantly higher than those of the NAFLD group (p<0.001). Inflammation with neutrophil infiltration was observed in only two rats in the NAFLD group. These results suggest that 2months of oral KRG or urushiol administration improves lipid profiles and stimulates NK cell activity, while inhibiting steatohepatitis in OLEFT rats. PMID:23369934

Hong, So Hyung; Suk, Ki Tae; Choi, Sang Hyeon; Lee, Jung Wook; Sung, Ho Taik; Kim, Chang Hoon; Kim, Eun Ji; Kim, Myoung Jo; Han, Sang Hak; Kim, Moon Young; Baik, Soon Koo; Kim, Dong Joon; Lee, Gyoung-Ja; Lee, Sang-Kyu; Park, Seung Ha; Ryu, Ohk Hyun

2013-01-29

62

Test tree  

SciTech Connect

A subsurface test tree so compact in its vertical dimension that the entire tree can be positioned below the blind rams in a blowout preventer stack. When the stinger is removed the remaining valve section of the tree will be below the blind rams in any conventional blowout preventer stack. The valve operators are split, one carried by the stinger and one carried in the valve housing with the arrangement of operator and valve in the housing providing an extremely small vertical dimension. A dome charge is effective on a piston to drive a ball valve to closed position to cut a line extending through the ball valve and to provide sequential operation between the ball valve on bottom and the valve thereabove which may be a flapper valve so that the lower valve closes and the line is cut before the upper valve closes. In one form the invention includes a subsurface safety valve below the test tree operated by one of control or balance pressure fluid.

Schwendemann, K. L.

1985-01-22

63

Technical Tree Climbing.  

ERIC Educational Resources Information Center

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

Jenkins, Peter

64

Murderous Trees  

NSDL National Science Digital Library

400 million years ago, in the early Devonian era, over half of all the creatures in the ocean were suddenly killed. This radio broadcast explains how millenia later, one scientist has finally found the possible culprit: trees and plants that evolved to produce soil excessive in nutrients. This soil washed into the sea, producing algae plumes and ultimately, low oxygen conditions that killed many marine organisms. The clip is 2 minutes in length.

65

Anti-ischemic activity and endothelium-dependent vasorelaxant effect of hydrolysable tannins from the leaves of Rhus coriaria (Sumac) in isolated rabbit heart and thoracic aorta.  

PubMed

The aim of this work was to investigate the cardioprotective activity of hydrolysable gallotannins from Rhus coriaria L. leaves extract (RCLE) in isolated rabbit heart preparations, submitted to low-flow ischemia/reperfusion damage. RCLE induces a dose-dependent normalization of coronary perfusion pressure (CPP), reducing left ventricular contracture during ischemia, and improving left ventricular developed pressure and the maximum rate of rise and fall of left ventricular pressure at reperfusion. Creatinine kinase (CK) and lactate dehydrogenase (LDH) outflow were significantly reduced during reperfusion. In parallel there was a rise in the release of the cytoprotective 6-ketoprostaglandin F (1alpha) (6-keto-PGF (1alpha)) and a decrease of tumor necrosis factor-alpha (TNF-alpha), both significant only at the highest RCLE concentrations (150-500 microg/mL). The vasorelaxant activity of RCLE was studied in isolated rabbit aorta rings precontracted with norepinephrine (NE) with and without endothelium. The vasorelaxation induced by RCLE was predominantly endothelium-dependent as demonstrated by the loss of RCLE vasorelaxant ability in i) de-endothelized rings and ii) in intact aortic rings after pretreatment with NG-monomethyl- L-arginine (L-NMMA) and 1 H-[1.2.4]oxadiazolo[4.3- A]quinoxalin-1-one (ODQ). The inhibition of vasorelaxation in intact rings by indomethacin (INDO) demonstrates the ability of RCLE to modulate the coronary endothelium cyclooxygenase (COX) pathway. The K-ATP channel antagonist glibenclamide (GLIB) was ineffective. The antioxidant activity of RCLE, investigated in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) model and in living cell systems (rat erythrocytes), was stronger than that of gallic acid, ascorbic acid and trolox. The structure of its main bioactive constituents, profiled by HPLC-ESI-HR-S, comprised a mixture of polygalloylated D-glucopyranose with different degrees of galloylation and 3- O-methylgallic acid. The cardiovascular protective effect of RCLE seems to be due to an interplay of different factors: COX pathway activation, TNF-alpha inhibition, endothelial nitric oxide synthase (eNOS) activation, and free radical and ROS scavenging. PMID:19548191

Beretta, Giangiacomo; Rossoni, Giuseppe; Santagati, Natale Alfredo; Facino, Roberto Maffei

2009-06-22

66

Tree Troubles  

NSDL National Science Digital Library

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

67

Random trees and applications  

Microsoft Academic Search

We discuss several connections between discrete and continuous random trees. In the discrete setting, we focus on Galton-Watson trees under various conditionings. In particular, we present a simple approach to Aldous’ theorem giving the convergence in distribution of the contour process of conditioned Galton-Watson trees towards the normalized Brownian excursion. We also briefly discuss applications to combinatorial trees. In the

Jean-François Le Gall

2005-01-01

68

The Needs of Trees  

ERIC Educational Resources Information Center

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

Boyd, Amy E.; Cooper, Jim

2004-01-01

69

A dynamic fault tree  

Microsoft Academic Search

The fault tree analysis is a widely used method for evaluation of systems reliability and nuclear power plants safety. This paper presents a new method, which represents extension of the classic fault tree with the time requirements. The dynamic fault tree offers a range of risk informed applications. The results show that application of dynamic fault tree may reduce the

Marko ?epin; Borut Mavko

2002-01-01

70

The Needs of Trees  

ERIC Educational Resources Information Center

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

Boyd, Amy E.; Cooper, Jim

2004-01-01

71

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

72

Growth of Lévy trees  

Microsoft Academic Search

We construct random locally compact real trees called Lévy trees that are the genealogical trees associated with continuous-state\\u000a branching processes. More precisely, we define a growing family of discrete Galton–Watson trees with i.i.d. exponential branch\\u000a lengths that is consistent under Bernoulli percolation on leaves; we define the Lévy tree as the limit of this growing family\\u000a with respect to the

Thomas Duquesne; Matthias Winkel

2007-01-01

73

Random real trees  

Microsoft Academic Search

We survey recent developments about random real trees, whose prototype is the\\u000aContinuum Random Tree (CRT) introduced by Aldous in 1991. We briefly explain\\u000athe formalism of real trees, which yields a neat presentation of the theory and\\u000ain particular of the relations between discrete Galton-Watson trees and\\u000acontinuous random trees. We then discuss the particular class of self-similar\\u000arandom

Jean-Francois Le Gall

2006-01-01

74

Fault tree handbook  

SciTech Connect

This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation.

Haasl, D.F.; Roberts, N.H.; Vesely, W.E.; Goldberg, F.F.

1981-01-01

75

Landscape in a Lacquer Box  

ERIC Educational Resources Information Center

|A symbolic dry landscape garden of Eastern origin holds a special fascination for the author's middle-school students, which is why the author chose to create a project exploring this view of nature. A dry landscape garden, or "karesansui," is an arrangement of rocks, worn by nature and surrounded by a "sea" of sand, raked into patterns…

Savage, Martha

2010-01-01

76

Tropical Tree Seed Manual.  

National Technical Information Service (NTIS)

The Tropical Tree Seed Manual is a one-volume reference manual for students, technicians, and scientists that provides comprehensive internationally compiled data about tropical trees. The emphasis is on species of the Americas; however, a number of tropi...

J. A. Vozzo

2002-01-01

77

Energy savings with trees  

Treesearch

Description: In conventional buildings, trees increase, decrease, or have little effect on energy use depending on general climate, building type, tree species, ... walls and roofs and wind protection from the direction of prevailing winter winds.

78

On Random Binary Trees.  

National Technical Information Service (NTIS)

Binary trees are examined combinatorially with the view of providing information useful in analyzing algorithms based on this widely used storage structure. Exact and asymptotic results are given for equally likely trees and those grown by binary insertio...

G. G. Brown B. O. Shubert

1976-01-01

79

Engineering laccases: in search for novel catalysts.  

PubMed

Laccases (p-diphenol oxidase, EC 1.10.3.2) are blue multicopper oxidases that catalyze the reduction of dioxygen to water, with a concomitant oxidation of small organic substrates. Since the description at the end of the nineteenth century of a factor catalyzing the rapid hardening of the latex of the Japanese lacquer trees (Rhus sp.) exposed to air laccases from different origins (plants, fungi bacteria) have been continuously discovered and extensively studied. Nowadays, molecular evolution and other powerful protein modification techniques offer possibilities to develop tailored laccases for a wide array of applications including drug synthesis, biosensors or biofuel cells. Here, we give an overview on strategies and results of our laboratory in the design of new biocatalysts based on laccases. PMID:21966250

Robert, Viviane; Mekmouche, Yasmina; Pailley, Pierre R; Tron, Thierry

2011-04-01

80

Build a Tree  

NSDL National Science Digital Library

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

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

2001-01-01

81

Omnivariate decision trees  

Microsoft Academic Search

Univariate decision trees at each decision node consider the value of only one feature leading to axis-aligned splits. In a linear multivariate decision tree, each decision node divides the input space into two with a hyperplane. In a nonlinear multivariate tree, a multilayer perceptron at each node divides the input space arbitrarily, at the expense of increased complexity and higher

C. T. Yildiz; Ethem Alpaydin

2001-01-01

82

Tree Pattern Relaxation  

Microsoft Academic Search

Abstract: Tree patterns are fundamental to querying tree-structureddata like XML. Because of the heterogeneity of XML data, it is oftenmore appropriate to permit approximate query matching and returnranked answers, in the spirit of Information Retrieval, than to return onlyexact answers. In this paper, we study the problem of approximate XMLquery matching, based on tree pattern relaxations, and devise efficientalgorithms to

Sihem Amer-yahia; Sungran Cho; Divesh Srivastava

2002-01-01

83

Everglades: Mangrove Tree  

Microsoft Academic Search

Pictured is a mangrove tree situated in the marsh of the Everglades. This tree is especially adapted to survive in this environment as they can survive in salt water and fresh water environments. There are three species of mangrove trees that can be found in the Everglades. These include: the red mangrove, the black mangrove, and the white mangrove. These

Chet Smolski

1978-01-01

84

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

85

Diary of a Tree.  

ERIC Educational Resources Information Center

Describes an activity to develop students' skills of observation and recordkeeping by studying the growth of a tree's leaves during the spring. Children monitor the growth of 11 tress over a 2-month period, draw pictures of the tree at different stages of growth, and write diaries of the tree's growth. (MDH)

Srulowitz, Frances

1992-01-01

86

Chem-Is-Tree  

Microsoft Academic Search

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

Dana M. Barry

1997-01-01

87

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

88

Complexity of Tree Homomorphisms  

Microsoft Academic Search

For a fixed oriented tree T, we consider the complexity of deciding whether or not a given digraph G is homomorphic to T. It was shown by Gutjahr, Woeginger and Welzl that there exist trees T for which this homomorphism problem is NP-complete. However, it seems difficult to decide just which trees T yield NP-complete homomorphism problems. In this paper,

Pavol Hell; Jaroslav Nesetril; Xuding Zhu

1996-01-01

89

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

90

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

91

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.

92

Overprvning Large Decision Trees  

Microsoft Academic Search

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

Jason Catlett

1991-01-01

93

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…

Rollinson, Susan Wells

2012-01-01

94

Cavitation in trees  

NASA Astrophysics Data System (ADS)

Sap is transported under tension (i.e. negative pressure) in trees, according to the tension-cohesion theory. Since water is physically instable under negative pressure, a risk of cavitation is possible. Techniques have been developed during the past two decennia to study cavitation in trees. Trees appear remarkably immune to cavitation events. Cavities form only when extreme water stresses occur or when sap freezes. Nucleation is heterogeneous in trees, presumably caused by the aspiration of air bubbles through conduit walls. Threshold xylem pressures for cavitation vary greatly between species, in concordance with the great functional and ecological diversity of trees. To cite this article: H. Cochard, C. R. Physique 7 (2006).

Cochard, Hervé

2006-11-01

95

Tree Owner's Manual for the Northeastern Midwestern United States  

Treesearch

Uncontrolled Keywords: tree owners manual, prune trees, tree care, planting trees, ... tree health, tree maintenance, Midwest trees, northeastern trees, tree crown, tree dripline, NA-FR-04-07 ... Resource Type: Management Plans and Reports.

96

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

2013-08-10

97

Inhibition of the PI3K-Akt/PKB survival pathway enhanced an ethanol extract of Rhus verniciflua Stokes-induced apoptosis via a mitochondrial pathway in AGS gastric cancer cell lines.  

PubMed

Rhus verniciflua Stokes (RVS) has been used in traditional Eastern Asia medicine for the treatment of gastritis and stomach cancer, although the mechanism for its biological activity remains to be elucidated. We previously established that an ethanol extract of RVS-induced G(1)-cell cycle arrest via accumulation of p27(Kip1) controlled by Skp2 reduction and apoptosis in AGS human gastric cancer cells. Here, we showed that an ethanol extract of RVS-induced apoptosis via caspase-9 activation (mitochondrial death pathway) is mediated by the loss of mitochondrial membrane potential (MMP, Deltapsi(m)) and the release of cytochrome C from the mitochondrial intermembrane space. In addition, an ethanol extract of RVS inactivated PI3K-Akt/PKB kinase in a time-dependent manner. Moreover, combined treatment of an ethanol extract of RVS and LY294002 (a PI3K inhibitor) markedly increased apoptosis compared to treatment with an ethanol extract of RVS alone. The role of PI3K-Akt/PKB in this process was confirmed by constitutive expression of inactive mutants of this kinase in AGS cells. Finally, siRNA-mediated knockdown of Akt/PKB expression resulted in a significant reduction in AGS cell proliferation. Taken together, these results suggest that an ethanol extract of RVS induces apoptosis via a mitochondrial death pathway in human gastric cancer cells, but not in normal cells, and inhibition of the PI3K-Akt/PKB pathway enhanced the mitochondrial death pathway. PMID:18378393

Kim, Ji Hye; Go, Ho Yeon; Jin, Dong Hoon; Kim, Hwang-Phill; Hong, Myung Hee; Chung, Woo-Yeop; Park, Jong-Hyeong; Jang, Jun Bock; Jung, Hee; Shin, Yong Cheol; Kim, Sung-Hoon; Ko, Seong-Gyu

2008-04-18

98

Isolation and structural characterization of unusual pyranoanthocyanins and related anthocyanins from Staghorn sumac (Rhus typhina L.) via UPLC-ESI-MS, (1)H, (13)C, and 2D NMR spectroscopy.  

PubMed

The six major anthocyanins found in the burgundy coloured fruits of Staghorn sumac (Rhus typhina L.) were isolated and the structures of four compounds were determined by NMR spectroscopic methods as being: 7-O-methyl-delphinidin-3-O-(2?galloyl)-?-d-galactopyranoside; 7-O-methyl-cyanidin-3-O-(2?galloyl)-?-d-galactopyranoside; 7-O-methyl-delphinidin-3-O-(2?'galloyl)-?-d-galactopyranoside-4-vinyl-catechol-3?-O-?-d-glucopyranoside; and 7-O-methyl-cyanidin-3-O-(2?'galloyl)-?-d-galactopyranoside-4-vinyl-catechol-3?-O-?-d-glucopyranoside, respectively. Additionally, two related anthocyanin compounds, cyanidin-3-O-(2?galloyl)-?-d-galactopyranoside and 7-O-methyl-cyanidin-3-O-?-d-galactopyranoside were also recovered, with NMR spectroscopic values closely matching previous reports from other plant species. The prevalence of 7-O-methyl anthocyanins and their galloylated derivatives in sumac is highly unusual, and warrants special attention. Additionally, the in planta occurrence of two 7-O-methyl-pyranoanothocyanin-vinyl-catechol aglycones, Sumadin A and Sumadin B, and their derivatives is noted. To our knowledge, E-ring glycosylated vinyl-catechol pyranoanthocyanins were previously unknown. PMID:23850248

Kirby, Christopher W; Wu, Tao; Tsao, Rong; McCallum, Jason L

2013-07-11

99

The Tree of Life  

NSDL National Science Digital Library

The Tree of Life website introduces students to diagrams called cladograms, which show how species are related through a common ancestor. The site explains how to read a cladogram and how to understand the family tree for all species on Earth. An interactive cladogram explains what species have in common at a branch in the tree. There is also a pie diagram illustrating the relative amounts of species and separate sections for each group of species showing fast facts and photos.

100

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

101

Recursively Imputed Survival Trees.  

PubMed

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

Zhu, Ruoqing; Kosorok, Michael R

2011-12-01

102

Recursively Imputed Survival Trees  

PubMed Central

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

Zhu, Ruoqing; Kosorok, Michael R.

2011-01-01

103

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

104

Tree nut oils  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

105

Medians and Steiner Trees.  

National Technical Information Service (NTIS)

The theory of Steiner trees deals with the problem of designing a network connecting a set of points and minimizing the total connection length. We consider this problem in median metric spaces. It is shown that Steiner trees exist and can be found in a f...

M. van de Vel E. Verheul

1993-01-01

106

Causal Trees: Interleaving + Causality  

Microsoft Academic Search

Causal Trees are a variant of Milner's Synchronization Trees with enriched action labels which supply indication of the observable causes of observable actions, thus providing us with an interleaving description of concurrent systems which faithfully expresses causality. This model borrows from the interleaving models most of their mathematical simplicity and enhances their descriptive power. Actually, Labelled Event Structures can be

Philippe Darondeau; Pierpaolo Degano

1990-01-01

107

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

108

Tree-adjoining grammars  

Microsoft Academic Search

this paper, we will describe a tree generating system called tree-adjoining grammar (TAG) and state some of the recent results about TAGs. The work on TAGs is motivated by linguistic considerations. However, a number of formal results have been established for TAGs, which we believe, would be of interest to researchers in formal languages and automata, including those interested in

Aravind Joshi; Yves Schabes

1997-01-01

109

Trees in Our Lives.  

ERIC Educational Resources Information Center

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

NatureScope, 1986

1986-01-01

110

Fault tree handbook  

Microsoft Academic Search

This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic

D. F. Haasl; N. H. Roberts; W. E. Vesely; F. F. Goldberg

1981-01-01

111

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

112

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…

Braus, Judy, Ed.

1992-01-01

113

Trees From Helicopters  

NSDL National Science Digital Library

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

Konicek-Moran, Richard

2008-04-01

114

Approximate Tree Pattern Matching  

Microsoft Academic Search

this article proceeds on the assumption that this question has a negative response.In particular, we discuss the best known algorithms for tree editing and several variations having todo with subtree removal, variable length don't cares, and alignment. We discuss both sequentialand parallel algorithms. We present negative results having to do with unordered trees (treeswhose sibling order is arbitrary) and a

Dennis Shasha; Kaizhong Zhang

1997-01-01

115

Spectroscopic Studies of Perturbed T1 Cu Sites in the Multicopper Oxidases Saccharomyces Cerevisiae Fet3p And Rhus Vernicifera Laccase: Allosteric Coupling Between the T1 And Trinuclear Cu Sites  

SciTech Connect

The multicopper oxidases catalyze the 4e{sup -} reduction of O{sub 2} to H{sub 2}O coupled to the 1e{sup -} oxidation of 4 equiv of substrate. This activity requires four Cu atoms, including T1, T2, and coupled binuclear T3 sites. The T2 and T3 sites form a trinuclear cluster (TNC) where O{sub 2} is reduced. The T1 is coupled to the TNC through a T1-Cys-His-T3 electron transfer (ET) pathway. In this study the two T3 Cu coordinating His residues which lie in this pathway in Fet3 have been mutated, H483Q, H483C, H485Q, and H485C, to study how perturbation at the TNC impacts the T1 Cu site. Spectroscopic methods, in particular resonance Raman (rR), show that the change from His to Gln to Cys increases the covalency of the T1 Cu?S Cys bond and decreases its redox potential. This study of T1?TNC interactions is then extended to Rhus vernicifera laccase where a number of well-defined species including the catalytically relevant native intermediate (NI) can be trapped for spectroscopic study. The T1 Cu?S covalency and potential do not change in these species relative to resting oxidized enzyme, but interestingly the differences in the structure of the TNC in these species do lead to changes in the T1 Cu rR spectrum. This helps to confirm that vibrations in the cysteine side chain of the T1 Cu site and the protein backbone couple to the Cu?S vibration. These changes in the side chain and backbone provide a possible mechanism for regulating intramolecular T1 to TNC ET in NI and partially reduced enzyme forms for efficient turnover.

Augustine, A.J.; Kragh, M.E.; Sarangi, R.; Fujii, S.; Liboiron, B.D.; Stoj, C.S.; Kosman, D.J.; Hodgson, K.O.; Hedman, B.; Solomon, E.I.; /Stanford U., Chem. Dept. /Copenhagen U. /SLAC, SSRL /SUNY, Buffalo

2009-04-30

116

X-Ray absorption edge determination of the oxidation state and coordination number of copper: application to the type 3 site in rhus vernicifera laccase and its reaction with oxygen  

SciTech Connect

Cu X-ray absorption edge features of 19 Cu(I) and 40 Cu(II) model complexes have been systematically studied and correlated with oxidation state and geometry. Studies of Cu(I) model complexes with different coordination number reveal that an 8983-8984-eV peak (assigned as the Cu 1s ..-->.. 4p transition) can be correlated in energy, shape, and intensity with ligation and site geometry of the cuprous ion. These Cu(I) edge features have been qualitatively interpreted with ligand field concepts. Alternatively, no Cu(II) complex exhibits a peak below 8985.0 eV. The limited intensity observed in the 8983-8985-eV region for some Cu(II) complexes is associated with the tail of an absorption peak at approx. 8986 eV which is affected by the covalency of the equatorial ligands. These models studies allow accurate calibration of a normalized difference edge procedure which is used for the quantitative determination of Cu(I) content in copper complexes of mixed oxidation state composition. This normalized difference edge analysis is then used to quantitatively determine the oxidation states of the copper sites in type 2 copper-depleted (T2D) and native forms of the multicopper oxidase, Rhus vernicifera laccase. The type 3 site of the T2D laccase is found to be fully reduced and stable to oxidation by O/sub 2/ or by 25-fold protein equivalents of ferricyanide, but it can be oxidized by reaction with peroxide. The increase in intensity of the 330-nm absorption feature which results from peroxide titration of T2D laccase is found to correlate linearly with the percent of oxidation of the binuclear copper site.

Kau, L.S.; Spira-Solomon, D.J.; Penner-Hahn, J.E.; Hodgson, K.O.; Solomon, E.I.

1987-10-14

117

The P-tree algebra  

Microsoft Academic Search

The Peano Count Tree (P-tree) is a quadrant-based lossless tree representation of the original spatial data. The idea of P-tree is to recursively divide the entire spatial data, such as Remotely Sensed Imagery data, into quadrants and record the count of 1-bits for each quadrant, thus forming a quadrant count tree. Using P-tree structure, all the count information can be

Qin Ding; Maleq Khan; Amalendu Roy; William Perrizo

2002-01-01

118

Tree pattern mining with tree automata constraints  

Microsoft Academic Search

Most work on pattern mining focuses on simple data structures such as itemsets and sequences of itemsets. However, a lot of recent applications dealing with complex data like chemical compounds, protein structures, XML and Web log databases and social networks, require much more sophisticated data structures such as trees and graphs. In these contexts, interesting patterns involve not only frequent

Sandra de Amo; Nyara A. Silva; Ronaldo P. Silva; Fabiola S. F. Pereira

2010-01-01

119

Language trees not equal gene trees.  

PubMed

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

Steele, James; Kandler, Anne

2010-06-09

120

Tw o-Way Comparison Search Trees AG eneralization of Binary Search Trees and Split Trees  

Microsoft Academic Search

Ag eneralization of binary search trees and binary split trees is developed that takes advantage of two-way key comparisons — the two-way comparison tree. The two-way comparison tree is shown to have little use for dynamic situations, but to be an improvement over the optimal binary sear ch tree and the opti- mal binary split tree for static data sets.

David Spuler

121

Wounded forests, starving trees  

SciTech Connect

Acid rain, insects, and fungi are real problems that can kill trees. Wounded and starving trees are also realities and part of the total picture. Forest decline is a many-sided problem, yet recent attention has focused on only a few visible factors. The blame for diebacks and declines can not always be placed on well-publicized short-term agents. Forestry practices may also play an important part in today's current tree problems. This paper examined past forestry practices to see if they could have predisposed forests to stress and therefore been a major factor in current forest problems. 8 references, 10 figures.

Shigo, A.L.

1985-11-01

122

What Tree Is It?  

NSDL National Science Digital Library

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

123

Discordance of Species Trees with Their Most Likely Gene Trees  

Microsoft Academic Search

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

James H. Degnan; Noah A. Rosenberg

2006-01-01

124

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

125

Tea tree oil.  

PubMed

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

Larson, David; Jacob, Sharon E

126

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

127

Individual tree control - Treesearch  

Treesearch

... differ considerably in value and within species individual trees differ in quality. Individual stem control is a mechanical or chemical weeding operation that ... The risk of bodily injury is an inherent safety problem with mechanical methods.

128

The Tree of Life  

NSDL National Science Digital Library

This article describes how interdisciplinary, thematic lessons about plants, animals, and the environment were introduced with children's literature. First-grade students created a display of the African baobab tree and its inhabitants, focusing on their interdependence.

Plummer, Donna M.; Macshara, Jeannie; Brown, Skila K.

2003-03-01

129

Trees as environmental sentinels.  

PubMed

Trees are reliable indicators of the long-term effects of atmospheric pollution. As the botanical big game of the planet they are also standing guard and may be providing a warning signal about our own future. PMID:11153123

Dickinson, N M

2000-09-01

130

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

131

Functional Trees for Regression  

Microsoft Academic Search

In this paper we present and evaluate a new algorithm for supervised learning regression problems. The algorithm combines\\u000a a univariate regression tree with a linear regression function by means of constructive induction. When growing the tree,\\u000a at each internal node, a linear-regression function creates one new attribute. This new attribute is the instantiation of\\u000a the regression function for each example

Joao Gama

2001-01-01

132

PGPR in Coniferous Trees  

Microsoft Academic Search

\\u000a Coniferous trees are widely distributed in the world and have tremendous environmental and economic importance. Large numbers\\u000a of bacteria live in the rhizosphere or rhizoplane of their roots, and some of these may promote tree growth through a variety\\u000a of mechanisms. Known as plant growth-promoting rhizobacteria (PGPR), such bacteria can promote growth either directly, by\\u000a liberating growth-regulating substances and increasing

Elke Jurandy Bran Nogueira Cardoso; Rafael Leandro de Figueiredo Vasconcellos; Carlos Marcelo Ribeiro; Marina Yumi Horta Miyauchi

133

Piecewise Testable Tree Languages  

Microsoft Academic Search

Abstract—This paper,presents a decidable,characterization,of tree languages,that can,be defined,by a boolean,combination of ! 1 formulas. This is a tree extension of the Simon theorem, which,says that a string language,can be defined by a boolean combination,of ! 1 formulas,if and,only if its syntactic monoid is J-trivial.

Mikolaj Bojanczyk; Luc Segoufin; Howard Straubing

2008-01-01

134

Trees for reclamation  

SciTech Connect

Land reclamation programs sponsored by several state forestry organizations are summarized in these presentations. The use of trees as a preferred specie for revegetation of surface mined lands is addressed. Modern methods of forestry can be used to make land economically and aesthetically acceptable. Tree planting techniques are presented and the role of Mycorrhizae is discussed. There are 30 papers included in this proceedings. States represented include: Alabama, Arkansas, Georgia, Illinois, Kansas, Kentucky, Maryland, Virginia, Iowa, Ohio, Pennsylvania, and West Virginia.

Not Available

1980-01-01

135

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

136

Quantum computation and decision trees  

Microsoft Academic Search

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

Edward Farhi; Sam Gutmann

1998-01-01

137

Unordered Tree Matching and Strict Unordered Tree Matching: The Evaluation of Tree Pattern Queries  

Microsoft Academic Search

In this paper, we consider two kinds of unordered tree matchings for evaluating tree pattern queries in XML databases. For the first kind of unordered tree matching, we propose a new algorithm, which runs in O(|D||Q|) time, where Q is a tree pattern and D is a largest data stream associated with a node of Q. It can also be

Yangjun Chen; Donovan Cooke

2010-01-01

138

Predictive Classification Trees  

NASA Astrophysics Data System (ADS)

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

Dlugosz, Stephan; Müller-Funk, Ulrich

139

How to Count Trees?  

NASA Astrophysics Data System (ADS)

We propose a new topological invariant of unlabeled trees of N nodes. The invariant is a set of N×2 matrices of integers, with ?j kdi, j and vi as the matrix elements, where di, j are the elements of the distance matrix and vi denotes ith node's degree and k??. To compare the invariant calculated for possibly different graphs, the matrix rows are ordered with respect to the first column, and, if necessary, with respect to the second one. We use the new invariant to evaluate from below the number of topologically different unlabeled trees up to N =17. The results slightly exceed the asymptotic evaluation of Otter.

Piec, Sebastian; Malarz, Krzysztof; Ku?akowski, Krzysztof

140

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

141

Lava trees and tree molds ("cannon stones") of Mt. Etna  

NASA Astrophysics Data System (ADS)

Unique volcanic structures, known in the literature as "lava trees" and "tree molds", have formed at several sites on Mt. Etna volcano (northeastern Sicily, Italy). They form when a fluid lava flow runs over a tree, wraps around it and, while the wood burns off, solidifies forming a hollow cast of the tree. The inhabitants of the Etna area call these formations "pietre cannone" ("cannon stones") because of their cylindrical shape. The first documentation of lava trees is from Hawaii, but the first eye-witnessed accounts of their formation are, to our knowledge, from Etna's 1865 eruption. Although many of the literature examples of lava trees and tree molds formed in pahoehoe, many of those reported in this work formed in a'a. The sites where we have found the lava tree molds are located within the territory of the Etna Regional Park; most occur next to walking trails and have a high potential for geotourism.

Carveni, Pietro; Mele, Giuliana; Benfatto, Santo; Imposa, Sebastiano; Salleo Puntillo, Maria

2011-08-01

142

The Probability of Topological Concordance of Gene Trees and Species Trees  

Microsoft Academic Search

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

Noah A. Rosenberg

2002-01-01

143

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

Microsoft Academic Search

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

Amir Rajabzadeh; Mohammad S. Jahangiry

2010-01-01

144

TREE LILAC CULTIVARS TESTED AS STREET TREES: INITIAL RESULTS  

Microsoft Academic Search

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

Henry D. Gerhold

1999-01-01

145

Tree Spanners for Subgraphs and Related Tree Covering Problems  

Microsoft Academic Search

For any fixed parameter k ¸ 1, a tree k-spanner of a graph G is a spanning tree T in G such that the distance between every pair of vertices in T is at most k times their distance in G. In this paper, we generalize on this very restrictive concept, and introduce Steiner tree k-spanners: We are given an

Dagmar Handke; Guy Kortsarz

2000-01-01

146

The suffix binary search tree and suffix AVL tree  

Microsoft Academic Search

Suffix trees and suffix arrays are classical data structures that are used to represent the set of suffixes of a given string, and thereby facilitate the efficient solution of various string processing problems—in particular on-line string searching. Here we investigate the potential of suitably adapted binary search trees as competitors in this context. The suffix binary search tree (SBST) and

Robert W. Irving; Lorna Love

2003-01-01

147

Tree reconstruction from partial orders.  

National Technical Information Service (NTIS)

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 m...

S. K. Kannan T. J. Warnow

1993-01-01

148

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

149

Multiquarks and Steiner trees  

NASA Astrophysics Data System (ADS)

A brief review review is presented of models tentatively leading to stable multiquarks. A new attempt is presented, based on a Steiner-tree model of confinement, which is inspired by by QCD. It leads to more attraction than the empirical colour-additive model used in earlier multiquark calculations, and predict several multiquark states in configurations with different flavours.

Richard, Jean-Marc

2010-10-01

150

Oblique Linear Tree  

Microsoft Academic Search

In this paper we present system Ltree for proposicional supervised learning. Ltree is able to define decision surfaces both orthogonal and oblique to the axes defined by the attributes of the input space. This is done c ombining a decision tree with a linear discriminant by means of constructive induction. At each decision n ode Ltree defines a new instance

Joao Gama

1997-01-01

151

Starting Trees from Cuttings.  

ERIC Educational Resources Information Center

|Describes a procedure for starting tree cuttings from woody plants, explaining "lag time," recommending materials, and giving step-by-step instructions for rooting and planting. Points out species which are likely candidates for cuttings and provides tips for teachers for developing a unit. (JM)|

Kramer, David C.

1983-01-01

152

Trees for bees  

Microsoft Academic Search

Controversy over the origins and evolution of social behaviour in the major groups of social bees (the corbiculate bees) has fuelled arguments over different approaches for building evolutionary trees. However, the application of different analytical methodologies does not explain why molecular and morphological data suggest strikingly different hypotheses for the evolution of eusociality in bees. Determining the phylogenetic root is

Peter J. Lockhart; Sydney A. Cameron

2001-01-01

153

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.

154

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

155

Digging Deeper with Trees.  

ERIC Educational Resources Information Center

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

Growing Ideas, 2001

2001-01-01

156

Arbutus unedo, Strawberry Tree  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

157

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

158

Formal Fault Tree Semantics  

Microsoft Academic Search

In train control systems, more and more (electro-)mechanical devices are substituted by software based devices. To sustain the high level safety standards for these embedded systems, we propose the integration of fault tree analysis and formal methods. This combines two important safety analysis methods from the involved domains of engineering and software development. Our approach proposes to build a formal

Gerhard Schellhorn; Andreas Thums; Wolfgang Reif Lehrstuhl

2002-01-01

159

Pear tree--`Elliot`  

US Patent & Trademark Office Database

A new and distinct variety of pear tree primarily characterized by its tolerance to the fire-blight organism. (Erwinia amylovora), and further characterized by a blooming habit concurrent with `Bartlett`; skin with firm and buttery texture, and fruit with a flavor which is excellent to good. The keeping quality of the fruit is good to excellent.

1988-12-06

160

The death of trees  

SciTech Connect

Every month, an area of tropical forest the size of Wales is felled. Species are becoming extinct, aboriginal peoples are being destroyed, and soil erosion is causing deserts where forests have stood. The Death of Trees looks at the dangers facing forests world wide - tropical, sub-tropical and temperate.

Dudley, N.

1985-01-01

161

PEACH TREE NAMED GULFCREST  

Technology Transfer Automated Retrieval System (TEKTRAN)

The invention relates to a new and distinct variety of peach [Prunus persica (L.) Batsch) tree which is named Gulfcrest. This new variety produces highly colored, clingstone, non-melting yellow flesh fruit which are suitable for the fresh market. Gulfcrest matures a few days after Flordacrest, app...

162

PEACH TREE NAMED GULFKING  

Technology Transfer Automated Retrieval System (TEKTRAN)

The invention relates to a new distinct variety of peach [Prunus persica (L.) Batsch] tree which is named Gulfking. This new variety produces highly colored clingstone, non-melting yellow flesh fruit which are suitable for the fresh market. Gulfking matures with Flordaking peach in early May in so...

163

Hug a Tree!  

ERIC Educational Resources Information Center

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

Rockwell, Robert E.; And Others

1983-01-01

164

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

165

Our Air: Unfit for Trees.  

ERIC Educational Resources Information Center

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

Dochinger, Leon S.

166

New Life From Dead Trees  

ERIC Educational Resources Information Center

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

DeGraaf, Richard M.

1978-01-01

167

Christmas trees and air pollution  

Microsoft Academic Search

In the mountainous Appalachian regions of Maryland and West Virginia commercial Christmas tree growers have been experiencing increasing air pollution injury in their plantations, especially to pines. Types of injuries included chlorosis and necrotic spotting of needles, as well as loss of needles and tree buds. Chronic needle injury generally follows long-term, low-level exposure to the pollutants. Damaged trees have

Dochinger

1973-01-01

168

Flow around a Living Tree  

Microsoft Academic Search

Flow around a living tree was investigated as basic research of a windbreak forest. A type of conifer, which is named ``goldcrest, '' was used as the test piece in a wind tunnel experiment. The drag coefficient of the living tree was measured in the range of a mean flow velocity of 5˜15m\\/s. The drag coefficient of the living tree

Hitoshi Ishikawa; Suguru Amano; Kenta Yakushiji

2006-01-01

169

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

170

The limits to tree height  

Microsoft Academic Search

Trees grow tall where resources are abundant, stresses are minor, and competition for light places a premium on height growth. The height to which trees can grow and the biophysical determinants of maximum height are poorly understood. Some models predict heights of up to 120m in the absence of mechanical damage, but there are historical accounts of taller trees. Current

George W. Koch; Stephen C. Sillett; Gregory M. Jennings; Stephen D. Davis

2004-01-01

171

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.

172

Relighting Photographs of Tree Canopies  

Microsoft Academic Search

We present an image-based approach to relighting photographs of tree canopies. Our goal is to minimize capture overhead; thus the only input required is a set of photographs of the tree taken at a single time of day, while allowing relighting at any other time. We first analyze lighting in a tree canopy both theoretically and using simulations. From this

Marcio Cabral; Nicolas Bonneel; Sylvain Lefebvre; George Drettakis

2011-01-01

173

Decidable Properties of Tree Languages  

Microsoft Academic Search

Abstract: The first part of the thesis concerns problems related to the question: "when can a regular tree language be defined in first-order logic?" Characterizations in terms of automata of first-order logic and the related chain logic are presented. A decidable property of tree automata called confusion is introduced; it is conjectured that a regular tree language can be defined

Mikolaj Bojanczyk

2004-01-01

174

Indexing and Mining Free Trees  

Microsoft Academic Search

Tree structures are used extensively in domains such as computational biology, pattern recognition, computer net- works, and so on. In this paper, we present an indexing tech- nique for free trees and apply this indexing technique to the problem of mining frequent subtrees. We first define a novel representation, the canonical form, for rooted trees and ex- tend the definition

Yun Chi; Yirong Yang; Richard R. Muntz

2003-01-01

175

Generating functions for generating trees  

Microsoft Academic Search

Certain families of combinatorial objects admit recursive descriptions in terms of gen- erating trees: each node of the tree corresponds to an object, and the branch leading to the node encodes the choices made in the construction of the object. Generating trees lead to a fast computation of enumeration sequences (sometimes, to explicit formulae as well) and provide efficient random

Cyril Banderier; Mireille Bousquet-mélou; Alain Denise; Philippe Flajolet; Danièle Gardy; Dominique Gouyou-beauchamps

2002-01-01

176

Random Trees, Heights, and Large Deviations  

Microsoft Academic Search

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

Nicolas Broutin

177

The roots of trees  

NASA Astrophysics Data System (ADS)

The root of a tree develops the twofold function of absorbing water mixed with mineral salts, and anchoring the plant to the substrate. The former activity is the more important in determining the spreading of a root. If, however, the root is regarded only as a bundle of stiffeners implanted in a semi-infinite elastic medium and we want to optimize its shape, then the problem can be reduced to an optimization problem in elasticity.

Villaggio, Piero

178

Create a Mangrove Tree  

NSDL National Science Digital Library

In this group activity, learners will explore the characteristics, functions and uniqueness of the mangrove tree. One learner dresses as a red mangrove while the group discusses and simulates high and low tide, salinity levels, salt balance, root systems, habitat, propagules (structures for reproduction), and dispersal. This demonstration works best as a review activity. If some materials (mangrove leaves, propagules, figurines of crabs and small fish) are not readily available, pictures or drawings can be substituted.

Aquarium, The F.

2010-01-01

179

Insert tree completion system  

SciTech Connect

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

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

1982-09-01

180

From event-labeled gene trees to species trees  

PubMed Central

Background Tree reconciliation problems have long been studied in phylogenetics. A particular variant of the reconciliation problem for a gene tree T and a species tree S assumes that for each interior vertex x of T it is known whether x represents a speciation or a duplication. This problem appears in the context of analyzing orthology data. Results We show that S is a species tree for T if and only if S displays all rooted triples of T that have three distinct species as their leaves and are rooted in a speciation vertex. A valid reconciliation map can then be found in polynomial time. Simulated data shows that the event-labeled gene trees convey a large amount of information on underlying species trees, even for a large percentage of losses. Conclusions The knowledge of event labels in a gene tree strongly constrains the possible species tree and, for a given species tree, also the possible reconciliation maps. Nevertheless, many degrees of freedom remain in the space of feasible solutions. In order to disambiguate the alternative solutions additional external constraints as well as optimization criteria could be employed.

2012-01-01

181

Integrated fault tree development environment  

Microsoft Academic Search

Probabilistic Risk Assessment (PRA) techniques are utilized in the nuclear industry to perform safety analyses of complex defense-in-depth systems. A major effort in PRA development is fault tree construction. The Integrated Fault Tree Environment (IFTREE) is an interactive, graphics-based tool for fault tree design. IFTREE provides integrated building, editing, and analysis features on a personal workstation. The design philosophy of

1986-01-01

182

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

183

Collapse of loaded fractal trees  

NASA Astrophysics Data System (ADS)

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

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

1985-02-01

184

Efficient Historical R-trees  

Microsoft Academic Search

The Historical R-tree is a spatio-temporal access method aimed at the retrieval of window queries in the past. The concept behind the method is to keep an R-tree for each timestamp in history, but allow consecutive trees to share branches when the underlying objects do not change. New branches are only created to accommodate updates from the previous timestamp. Although

Yufei Tao; Dimitris Papadias

2001-01-01

185

Fault trees and sequence dependencies  

Microsoft Academic Search

One of the frequency cited shortcomings of fault-tree models, their inability to model so-called sequence dependencies, is discussed. Several sources of such sequence dependencies are discussed, and new fault-tree gates to capture this behavior are defined. These complex behaviors can be included in present fault-tree models because they utilize a Markov solution. The utility of the new gates is demonstrated

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

1990-01-01

186

Harvesting small trees for biomass  

Microsoft Academic Search

This study evaluated precommercial, full-tree thinning of saplings and small poletimber (1-8 inches depth breadth and height) using chainsaws and modified farm tractors for skidders. To facilitate cutting large numbers of small trees (1-5 inches), the chainsaw was fitted with a felling frame. The cutter felled and manually bunched up to 145 trees\\/2.7 tons per productive manhour. Average production, assuming

Hoffman

1986-01-01

187

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

188

Project Learning Tree  

NSDL National Science Digital Library

Project Learning Tree is a national environmental education program containing a series of learning modules with inquiry-oriented activities for K-12 students and educators that address current environmental topics and issues. These topics range from forests, wildlife and water to community planning, waste management and energy. The materials correlate with the national environmental education performance standards. The curriculum is available for a fee; materials must be ordered or obtained by attending a professional development workshop. The newsletter and an environmental action project guide are free.

189

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

190

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

191

A Novel Approach for Compressing Phylogenetic Trees  

Microsoft Academic Search

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

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

2010-01-01

192

Tree Stabilization: Current Products and Practices  

Microsoft Academic Search

Products and systems used to stabilize trees at transplant should be prescribed based on site conditions, tree charac- teristics, and planting and maintenance practices. Alternatives to traditional aboveground trunk staking and guying methods exist, generally consisting of products that anchor tree rootballs rather than supporting tree trunks. When assessing the need for tree stabilization at transplant, several factors should be

Bonnie L. Appleton; Carolyn M. Cannella; P. Eric Wiseman; Alexis A. Alvey

2008-01-01

193

Resistance angle sensor based tree diameter gauge  

Microsoft Academic Search

Accurate measurement of the tree diameter is important for the production and scientific research of forestry. The paper developed a resistance angle sensor based on tree diameter gauge, which provided a resolution to some difficulties in tree diameter measuring, such as big trees and trees with spine. The height measuring module based on ultrasonic sensor made it easy to find

Feng Zhi-hui; Chen Wei-mian; Shen Jin-feng; Fang Yi-ming

2010-01-01

194

ECONOMIC ANALYSIS OF URBAN TREE REPLACEMENT DECISIONS  

Microsoft Academic Search

A critical decision facing urban foresters, arborists, and planners involves deciding when an existing tree should be removed and replaced with a new plant- ing. Tree removal decisions are often based on an evaluation of the tree's health and condition as well as safety concerns. A tree may be retained, but nor- mally this requires a tree maintenance program and

Jessie L. Scott; David R. Betters

2000-01-01

195

Metasearch with Ordered Tree Structured Patterns  

Microsoft Academic Search

Due to the rapid growth of tree structured data such as Web documents, ecient learn- ing from tree structured data becomes more and more important. We have proposed ordered tree structured patterns with internal structured variables, called ordered term trees, in order to represent structural features common to such tree structured data. In this paper, we propose a method for

Kazuhide Aikou; Yusuke Suzuki; Takayoshi Shoudai; Tetsuhiro Miyaharay

196

Edge version of the matrix tree theorem for trees  

Microsoft Academic Search

We provide a combinatorial description of all the minors of the edge version of the Laplacian matrix of a mixed tree. The description involves the common SDR's for the forests obtained by deleting from the tree the edge sets corresponding to the row and column indices of the minor.

Ravindra B. Bapat; Jerrold W. Grossman; Devadatta M. Kulkarni

2000-01-01

197

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

198

Growth-dependent tree mortality models based on tree rings  

Microsoft Academic Search

Mortality is a crucial element of population dynamics. However, tree mortality is not well understood, par- ticularly at the individual level. The objectives of this study were to (i) determine growth patterns (growth levels and growth trends) over different time windows that can be used to discriminate between dead and living Norway spruce (Picea abies (L.) Karst.) trees, (ii) optimize

Christof Bigler; Harald Bugmann

2003-01-01

199

A forest beyond the trees: Tree cutting in rural Ghana  

Microsoft Academic Search

In this paper I examine the complexity of human forces involved in tree cutting in a Ghanaian forest region. I provide evidence to link the indiscriminate tree-cutting activities of some local communities to the gradual loss of communal control over land and the replacement of kin group control with state property regimes. I point to the interrelated factors of the

George J. S. Dei

1992-01-01

200

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

2013-02-25

201

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

202

Evolution of Multiple Tree Structured Patterns from Tree-Structured Data Using Clustering  

Microsoft Academic Search

We propose a new genetic programming approach to extraction of multiple tree structured patterns from tree-structured data\\u000a using clustering. As a combined pattern we use a set of tree structured patterns, called tag tree patterns. A structured variable\\u000a in a tag tree pattern can be substituted by an arbitrary tree. A set of tag tree patterns matches a tree, if

Masatoshi Nagamine; Tetsuhiro Miyahara; Tetsuji Kuboyama; Hiroaki Ueda; Kenichi Takahashi

2008-01-01

203

Quad-Trees, Oct-Trees, and K-Trees: A Generalized Approach to Recursive Decomposition of Euclidean Space  

Microsoft Academic Search

K-trees are developed as a K-dimensional analog of quad-trees and oct-trees. K-trees can be used for modeling K-dimensional data. A fast algorithm is given for finding the boundary size of a K-dimensional object represented by a K-tree. For K considered as con-stant; the algorithm provides a method for computing the perimeter of a quad-tree encoded image or the surface area

Chris L. Jackins; Steven L. Tanimoto

1983-01-01

204

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

Microsoft Academic Search

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

NOAH A. ROSENBERG; RANDA TAO

2008-01-01

205

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

206

Geometric group actions on trees  

Microsoft Academic Search

W e def inegeometric group actions on -trees, as dual to a measured foliation on a 2- complex with some finiteness and injectivity properties. We prove that an action is nongeometric if and only if it is a nontrivial strong limit in the sense of Gillet-Shalen. We give a simple new construction of the Bass-Serre tree of a graph of

Gilbert Levitt; Frederic Paulin

1997-01-01

207

New water tree monitoring technique  

Microsoft Academic Search

The design philosophy is given for producing image currents depicting water motion during water treeing. A diagnostic for water treeing in polyethylene (PE) is being developed from a successful one for prebreakdown studies in liquids. The basic technique is to stress a dielectric between two electrodes and observe image currents in the ground electrode. Direct measurement of motion appears to

M. O. Pace; F. F. Dyer; T. V. Blalock; B. E. Williams; S. W. Milam; I. Alexeff; T. J. Rodenbaugh

1990-01-01

208

Neural trees for image segmentation  

Microsoft Academic Search

In this paper we report the application of neural trees for image segmentation of magnetic resonance (MR) images. The network, built up during training, effectively partitions the feature space into subregions and each final subregion is assigned a class label according to the data routed to it. As the tree grows, the number of training data for each node decreases,

Iren Valova; Yukio Kosugi

1997-01-01

209

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

210

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

211

Spatial Joins Using Seeded Trees  

Microsoft Academic Search

Existing methods for spatial joins assume the existence of indices for the participating data sets. This assumption is not realistic for applications involving multiple map layer overlays or for queries involving non-spatial selections. In this paper, we explore a spatiaJ join method that dynamically constructs index trees called seeded trees at join time. This method uses knowledge of thedata sets

Ming-Ling Lo; Chinya V. Ravishankar

1994-01-01

212

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.

Tekaia, Fredj; Yeramian, Edouard

2005-01-01

213

Vulnerability of Tasmanian giant trees  

Microsoft Academic Search

Summary Tasmania's giant trees are among the world's tallest flowering plants and Australia's greatest eucalypts. However, they are not well protected in National Parks or extensive reserves. Of the 69 known trees that meet the official criteria for protection as giants, almost 90% are in State forests managed for wood harvesting. Several of the giants are within coupes that were

Walter Herrmann

214

The limits to tree height.  

PubMed

Trees grow tall where resources are abundant, stresses are minor, and competition for light places a premium on height growth. The height to which trees can grow and the biophysical determinants of maximum height are poorly understood. Some models predict heights of up to 120 m in the absence of mechanical damage, but there are historical accounts of taller trees. Current hypotheses of height limitation focus on increasing water transport constraints in taller trees and the resulting reductions in leaf photosynthesis. We studied redwoods (Sequoia sempervirens), including the tallest known tree on Earth (112.7 m), in wet temperate forests of northern California. Our regression analyses of height gradients in leaf functional characteristics estimate a maximum tree height of 122-130 m barring mechanical damage, similar to the tallest recorded trees of the past. As trees grow taller, increasing leaf water stress due to gravity and path length resistance may ultimately limit leaf expansion and photosynthesis for further height growth, even with ample soil moisture. PMID:15103376

Koch, George W; Sillett, Stephen C; Jennings, Gregory M; Davis, Stephen D

2004-04-22

215

On the Count of Trees  

Microsoft Academic Search

Regular tree grammars and regular path expressions constitute core constructs widely used in programming languages and type systems. Nevertheless, there has been little research so far on frameworks for reasoning about path expressions where node cardinality constraints occur along a path in a tree. We present a logic capable of expressing deep counting along paths which may include arbitrary recursive

Everardo Barcenas; Pierre Geneves; Nabil Layaida; Alan Schmitt

2010-01-01

216

Counting in Trees for Free  

Microsoft Academic Search

Abstract In [22], it was shown that MSO logic for ordered unranked trees becomes undecidable if Presburger constraints are allowed at children of nodes We now show that a decidable logic is obtained if we use a a modal ?xpoint logic instead We present an automata theoretic characterization of this logic by means of deterministic Pres - burger tree automata

Helmut Seidl; Thomas Schwentick; Anca Muscholl; Peter Habermehl

2004-01-01

217

The tree of one percent  

PubMed Central

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

Dagan, Tal; Martin, William

2006-01-01

218

TREES MODIFY THE URBAN MICROCLIMATE  

Microsoft Academic Search

A person's feeling of thermal comfort is affected by en- vironmental conditions, including solar radiation, air tempera- ture, wind, humidity, longwave radiation, and precipitation. Trees modify all of these variables and therefore affect indivi- dual thermal comfort. Shade and wind protection are well- recognized efforts. But trees and other vegetation also con- tribute to cooling the air by the evaporative

C. A. Federer

219

Carbon14 in tree rings  

Microsoft Academic Search

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

William F. Cain; Hans E. Suess

1976-01-01

220

Carbon 14 in tree rings  

Microsoft Academic Search

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

William F. Cain; Hans E. Suess

1976-01-01

221

7 CFR 1214.3 - Christmas tree.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

222

Schoolyard Trees: Planning and Planting for Survival.  

ERIC Educational Resources Information Center

|Considers factors that affect the fate of schoolyard trees and focuses on the importance of what is considered during tree selection. Includes of list of characteristics of tree projects that have a low survival rate. (DDR)|

Coffey, Ann

2001-01-01

223

Subsea tree cap well choke system  

SciTech Connect

This patent describes an apparatus useful in subsea well completions requiring a subsea choke. It comprises: a wellhead connector; a tree flow passage; a tree annulus passage; a tree cap; a choke; and a production line.

Bednar, J.M.

1991-04-30

224

The P-tree Algebra1, 2  

Microsoft Academic Search

The Peano Count Tree (P-tree) is a quadrant-based lossless tree representation of the original spatial data. The idea of P-tree is to recursively divide the entire spatial data, such as Remotely Sensed Imagery data, into quadrants and record the count of 1-bits for each quadrant, thus forming a quadrant count tree. Using P-tree structure, all the count information can be

Qin Ding; Maleq Khan; Amalendu Roy; William Perrizo

225

Packing and Hausdorff Measures of Stable Trees  

Microsoft Academic Search

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

Thomas Duquesne

2010-01-01

226

Relighting photographs of tree canopies.  

PubMed

We present an image-based approach to relighting photographs of tree canopies. Our goal is to minimize capture overhead; thus the only input required is a set of photographs of the tree taken at a single time of day, while allowing relighting at any other time. We first analyze lighting in a tree canopy both theoretically and using simulations. From this analysis, we observe that tree canopy lighting is similar to volumetric illumination. We assume a single-scattering volumetric lighting model for tree canopies, and diffuse leaf reflectance; we validate our assumptions with synthetic renderings. We create a volumetric representation of the tree from 10-12 images taken at a single time of day and use a single-scattering participating media lighting model. An analytical sun and sky illumination model provides consistent representation of lighting for the captured input and unknown target times. We relight the input image by applying a ratio of the target and input time lighting representations. We compute this representation efficiently by simultaneously coding transmittance from the sky and to the eye in spherical harmonics. We validate our method by relighting images of synthetic trees and comparing to path-traced solutions. We also present results for photographs, validating with time-lapse ground truth sequences. PMID:21041884

Cabral, Marcio; Bonneel, Nicolas; Lefebvre, Sylvain; Drettakis, George

2011-10-01

227

Terrestrial apes and phylogenetic trees  

PubMed Central

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

Arsuaga, Juan Luis

2010-01-01

228

Through bore subsea christmas trees  

SciTech Connect

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

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

1985-01-01

229

How Monkeys Use Energy to Leap from Tree to Tree  

NSDL National Science Digital Library

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

Watson, David E.

230

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

231

Sentiment Classification Based on Syntax Tree Pruning and Tree Kernel  

Microsoft Academic Search

Sentiment classification is a way to analyze the subjective information in the text and then mine the opinion. We focus on the sentence-level sentiment classification. On the systematically analyzing the importance and difficulties of the sentence-level sentiment classification, this paper proposes a syntax tree pruning and tree kernel-based approach to sentiment classification. In our method, the convolution kernel of SVM

Zhang Wei; Li Peifeng; Zhu Qiaoming

2010-01-01

232

A Characterization of Attributed Tree Transformations by a Subclass of Macro Tree Transducers  

Microsoft Academic Search

.    We present a characterization of the class of tree transformations computed by (noncircular) attributed tree transducers,\\u000a in terms of a subclass of macro tree transducers, called attributed-like macro tree transducers. In fact, we prove formally\\u000a that attributed tree transducers and attributed-like macro tree transducers generate the same class of tree transformations.\\u000a Moreover, we prove that it is decidable

Zoltán Fülöp; Heiko Vogler

1999-01-01

233

Community Tree Planting Guide - Treesearch  

Treesearch

As a volunteer or professional, you are important to the health and well being of your community. ... It begins by assessing your planning site and concludes with long term care for your trees. ... Resource Type: Management Plans and Reports.

234

MicroRNAs in trees.  

PubMed

MicroRNAs (miRNAs) are 20-24 nucleotide long molecules processed from a specific class of RNA polymerase II transcripts that mainly regulate the stability of mRNAs containing a complementary sequence by targeted degradation in plants. Many features of tree biology are regulated by miRNAs affecting development, metabolism, adaptation and evolution. MiRNAs may be modified and harnessed for controlled suppression of specific genes to learn about gene function, or for practical applications through genetic engineering. Modified (artificial) miRNAs act as dominant suppressors and are particularly useful in tree genetics because they bypass the generations of inbreeding needed for fixation of recessive mutations. The purpose of this review is to summarize the current status of information on miRNAs in trees and to guide future studies on the role of miRNAs in the biology of woody perennials and to illustrate their utility in directed genetic modification of trees. PMID:22161564

Sun, Ying-Hsuan; Shi, Rui; Zhang, Xing-Hai; Chiang, Vincent L; Sederoff, Ronald R

2011-12-08

235

Topic in Depth - Tree Troubles  

NSDL National Science Digital Library

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

2010-09-14

236

Performance Evaluation of Main-Memory R-tree Variants  

Microsoft Academic Search

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

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

2003-01-01

237

Scalable Visualisations with Ownership Trees  

Microsoft Academic Search

Ownership trees are a simple yet powerful method of extracting an object-oriented program's implicit aggregation structure from its object graph. The topology of a program's ownership tree is independent of scale object-oriented programs are constructed from objects, and the relationship between a whole system and its top-level components is the same as the relationship between a low-level data structure and

Trent Hill; James Noble; John Potter

2000-01-01

238

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.

Takacs, L

1992-01-01

239

On the Count of Trees  

Microsoft Academic Search

Regular tree grammars and regular path expressions constitute core constructs\\u000awidely used in programming languages and type systems. Nevertheless, there has\\u000abeen little research so far on frameworks for reasoning about path expressions\\u000awhere node cardinality constraints occur along a path in a tree. We present a\\u000alogic capable of expressing deep counting along paths which may include\\u000aarbitrary recursive

Everardo Barcenas; Pierre Geneves; Nabil Layaida; Alan Schmitt

2010-01-01

240

Hierarchical buffered routing tree generation  

Microsoft Academic Search

This paper presents a solution to the problem of per- formance-driven buffered routing tree generation for VLSI cir- cuits. Using a novel bottom-up construction algorithm and a local neighborhood search strategy, our polynomial time algorithm finds the optimum solution in an exponential-size solution sub- space. The final output is a buffered rectilinear Steiner routing tree that connects the driver of

Amir H. Salek; Jinan Lou; Massoud Pedram

2002-01-01

241

On packing R-trees  

Microsoft Academic Search

We propose new R-tree packing techniques for static databases. Given a collection of rectangles, we sort them and build the R-tree bottom-up. There are several ways to sort the rectangles; the innovation of this work is the use of fractals, and specifically the hilbert curve, to achieve better ordering of the rectangles and eventually better pack- ing. We proposed and

Ibrahim Kamel; Christos Faloutsos

1993-01-01

242

MODELING AND RENDERING REALISTIC TREES  

Microsoft Academic Search

ABSTRACT This thesis presents a shape grammar,for the procedural modeling of trees that faithfully reproduces the botanical characteristics visible in nature. The shape grammar allows for modeling of the trunk and higher-level branches, as well as the details of compound,leaves without resorting to image-based approximation strate- gies. The prioritized grammar,rules illustrate the development of hierarchical and detailed tree models. This

Deepali Bhagvat

2008-01-01

243

Growing a Forest for the Trees.  

ERIC Educational Resources Information Center

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

Growing Ideas, 2001

2001-01-01

244

Exploring Multiple Trees through DAG Representations  

Microsoft Academic Search

We present a Directed Acyclic Graph visualisation designed to allow interaction with a set of multiple classification trees, specifically to find overlaps and differences between groups of trees and individual trees. The work is motivated by the need to find a representation for multiple trees that has the space-saving property of a general graph representation and the intuitive parent-child direction

Martin Graham; Jessie B. Kennedy

2007-01-01

245

Sensitivity analysis of modular dynamic fault trees  

Microsoft Academic Search

Dynamic fault tree analysis, as currently supported by the Galileo software package, provides an effective means for assessing the reliability of embedded computer-based systems. Dynamic fault trees extend traditional fault trees by defining special gates to capture sequential and functional dependency characteristics. A modular approach to the solution of dynamic fault trees effectively applies Binary Decision Diagram (BOD) and Markov

Yong Ou; Joanne Bechta Dugan

2000-01-01

246

Decidability of MSO Theories of Tree Structures  

Microsoft Academic Search

In this paper we provide an automaton-based solution to the decision problem for a large set of monadic second-order theories of deterministic tree structures. We achieve it in two steps: flrst, we reduce the considered problem to the problem of determining, for any Rabin tree automaton, whether it accepts a given tree; then, we exploit a suitable notion of tree

Angelo Montanari; Gabriele Puppis

2004-01-01

247

FIELD GUIDE FOR VISUAL TREE ASSESSMENT (VTA)  

Microsoft Academic Search

The VTA-Method (VISUAL TREE ASSESSMENT) consists in three steps. Visual control of the tree in order to find external symptoms of internal defects. If the constant stress distribution in a tree is disturbed due to the presence of a defect the tree attaches more wood at the overloaded spot. So bulges or dents are formed near decayed hollows and ribs

Clous Mattheck; Helge Breloer

1994-01-01

248

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

249

THE FACTOR STRUCTURE OF STREET TREE ATTRIBUTES  

Microsoft Academic Search

A factor analysis of 816 householder evaluations of street trees showed a general benefits factor and discrete annoyance factors in such areas as ground disturbance, disease, reduced visibility, and debris from fallen tree parts. Benefits were more highly related than annoyances to overall satisfaction with the street tree. The findings have implications for management of street trees and for future

Robert Sommer; Barbara A. Sommer

1989-01-01

250

ICE STORM DAMAGE TO URBAN TREES  

Microsoft Academic Search

A damage survey of parkway trees in Urbana, Illinois was made to determine critical removal and repair needs of trees immediately following a severe ice storm. Siberian elm, honeylocust, Bradford pear, common Hackberry, pin oak, sycamore, green ash, and tuliptree were among the 25 major parkway tree species that sustained considerable ice damage. Larger diameter trees with broader crowns incurred

Richard J. Hauer; Weishen Wang; Jeffrey O. Dawson

1993-01-01

251

Decision tree pruning using backpropagation neural networks  

Microsoft Academic Search

Neural networks have been widely applied to various tasks, such as handwritten character recognition, autonomous robot driving, determining the consensus base in DNA sequences. We describe the use of backpropagation neural networks for pruning decision trees. Decision tree pruning is indispensable for making the overfitting trees more accurate in classifying unseen data. In decision trees, the overfitting can occur when

BOONSERM KIJSIRIKUL; KONGSAK CHONGKASEMWONGSE

2001-01-01

252

Constructing Big Trees from Short Sequences  

Microsoft Academic Search

The construction of evolutionary trees is a fundamental problem in biology, and yet methods for reconstructing evolutionary trees are not reliable when it comes to inferring accurate topologies of large divergent evolutionary trees from realistic length sequences. We address this problem and present a new polynomial time algorithm for recon- structing evolutionary trees called the Short Quartets Method which is

L. ErdSs; Michael A. Steel; A. Sz

253

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

254

Toxicology of Poison Oak (Rhus toxicodendron) and Poison Ivy (Rhus radicans) Extracts in the Rat.  

National Technical Information Service (NTIS)

The objective of the study was to determine the toxicity of extracts of poison ivy, poison oak, and a polyethylene glycol vehicle (Carbowax R) when given orally to rats. Throughout a seven-month study four groups of rats (N=15) were administered the follo...

C. W. Waller I. W. Waters

1974-01-01

255

Exploring Within-tree Architectural Development of Two Apple Tree Cultivars Over 6 Years  

Microsoft Academic Search

The present study addresses the prediction of apple tree development, taking into account both the number and within-tree position of tree components. The architectural development of two trees per scion cultivar, 'Fuji' and 'Braeburn', was studied by describing all shoots over 6 years. Flowering and fruiting were observed over 3 years. The description included different scales (entire trees, axes, growth

E. C OSTES; H. S INOQUET; J. J. K EL N E R; C. G ODIN

2003-01-01

256

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

257

FEP 4.16. Fault-tree, Event tree, & P&ID Editors  

Microsoft Academic Search

FEP4.16 is a program developed to provide a common access to a suite of graphical tools developed for performing Probabilistic Risk Assessment (PRA). These tools include the graphical event tree, fault tree, and P and ID editors. The event tree editor allows the analyst to construct and modify graphical event trees. The fault tree editor allows the user to construct

1994-01-01

258

Spectrum of Variable-Random Trees  

Microsoft Academic Search

In this paper, we show that a continuous spectrum of randomisation exists, in which most ex- isting tree randomisations are only operating around the two ends of the spectrum. That leaves a huge part of the spectrum largely unexplored. We propose a base learner VR-Tree which generates trees with variable-randomness. VR-Trees are able to span from the conventional deterministic trees

Fei Tony Liu; Kai Ming Ting; Yang Yu; Zhi-hua Zhou

2008-01-01

259

Variable Tree Automata over Infinite Ranked Alphabets  

Microsoft Academic Search

\\u000a We introduce variable tree automata with infinite input ranked alphabets. Our model is based on an underlying bottom-up tree\\u000a automaton over a finite ranked alphabet containing variable symbols. The underlying tree automaton computes its tree language,\\u000a and then replaces the variable symbols with symbols from the infinite alphabet following certain rules. We show that the class\\u000a of recognizable tree languages

Irini-Eleftheria Mens; George Rahonis

260

R-trees with Update Memos  

Microsoft Academic Search

The problem of frequently updating multi-dimensional indexes arises in many location-dependent applications. While the R-tree and its variants are one of the dominant choices for indexing multi-dimensional objects, the R-tree exhibits inferior performance in the presence of frequent up- dates. In this paper, we present an R-tree variant, termed the RUM-tree (stands for R-tree with Update Memo) that minimizes the

Xiaopeng Xiong; Walid G. Aref

2006-01-01

261

A System for Approximate Tree Matching  

Microsoft Academic Search

Ordered, labeled trees are trees in which each node has a label and the left-to-right order of its children (if it has any) is fixed. Such trees have many applications in vision, pattern recognition, molecular biology, programming compilation, and natural language processing. Many of the applications involve comparing trees or retrieving\\/extracting information from a repository of trees. Examples include classification

Jason Tsong-li Wang; Kaizhong Zhang; Karpjoo Jeong; Dennis Shasha

1994-01-01

262

Sussing Merger Trees: The Merger Trees Comparison Project  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

263

Sussing Merger Trees: The Merger Trees Comparison Project  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

264

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

PubMed

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

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

265

Nitrogen nutrition of poplar trees.  

PubMed

Many forest ecosystems have evolved at sites with growth-limiting nitrogen (N) availability, low N input from external sources and high ecosystem internal cycling of N. By contrast, many poplar species are frequent constituents of floodplain forests where they are exposed to a significant ecosystem external supply of N, mainly nitrate, in the moving water table. Therefore, nitrate is much more important for N nutrition of these poplar species than for many other tree species. We summarise current knowledge of nitrate uptake and its regulation by tree internal signals, as well as acquisition of ammonium and organic N from the soil. Unlike herbaceous plants, N nutrition of trees is sustained by seasonal, tree internal cycling. Recent advances in the understanding of seasonal storage and mobilisation in poplar bark and regulation of these processes by temperature and daylength are addressed. To explore consequences of global climate change on N nutrition of poplar trees, responses of N uptake and metabolism to increased atmospheric CO(2) and O(3) concentrations, increased air and soil temperatures, drought and salt stress are highlighted. PMID:20398235

Rennenberg, H; Wildhagen, H; Ehlting, B

2010-03-01

266

A purposeful classification of tree decay detection tools  

Microsoft Academic Search

Tree management professionals face a daunting task in assessing tree health given large tree populations, high diversity of tree species and numerous types of tree diseases. Fortunately, there are now a variety of tree decay detection tools available. To be effective, tree management professionals will need to select the appropriate tool(s) often within a limited budget. The objective of this

Eng-Choon Leong; Daniel C. Burcham; Yok-King Fong

2012-01-01

267

Evolution of multiple tree structured patterns using soft clustering  

Microsoft Academic Search

We propose a new genetic programming (GP) approach to extracting multiple tree structured patterns from tree structured data using soft clustering. We use a set of multiple tree structured patterns, called tag tree patterns, as a combined pattern. A structured variable in a tag tree pattern can be substituted by an arbitrary tree. A set of multiple tag tree patterns

Kengo Yoshida; Tetsuhiro Miyahara; Tetsuji Kuboyama

2010-01-01

268

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

Microsoft Academic Search

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

George F. Georgakopoulos

2004-01-01

269

Integrated fault tree development environment  

SciTech Connect

Probabilistic Risk Assessment (PRA) techniques are utilized in the nuclear industry to perform safety analyses of complex defense-in-depth systems. A major effort in PRA development is fault tree construction. The Integrated Fault Tree Environment (IFTREE) is an interactive, graphics-based tool for fault tree design. IFTREE provides integrated building, editing, and analysis features on a personal workstation. The design philosophy of IFTREE is presented, and the interface is described. IFTREE utilizes a unique rule-based solution algorithm founded in artificial intelligence (AI) techniques. The impact of the AI approach on the program design is stressed. IFTREE has been developed to handle the design and maintenance of full-size living PRAs and is currently in use.

Dixon, B.W.

1986-01-01

270

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

2007-03-01

271

Transport of Methane in Trees  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

272

Properties of Consensus Methods for Inferring Species Trees from Gene Trees  

PubMed Central

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

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

2009-01-01

273

Tree hydraulics: how sap rises  

NASA Astrophysics Data System (ADS)

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 transpiration or capillary action; we investigate the effectiveness of both these forces for the two conduit architectures considered. The level of analysis is appropriate for undergraduates. The subject is of broad interest because it provides a naturally-occurring example of an unusual metastable state of matter: liquid under tension.

Denny, Mark

2012-01-01

274

Water Transport in Trees--An Artificial Laboratory Tree  

ERIC Educational Resources Information Center

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

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

2011-01-01

275

CONTEXT-TREE WEIGHTING FOR EXTENDED TREE SOURCES  

Microsoft Academic Search

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

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

276

Whole tree harvesting systems for wood fuel.  

National Technical Information Service (NTIS)

Whole tree harvesting systems for wood fuel, including both integrated harvesting and whole tree comminution systems, have been investigated in a series of harvesting trials. Integrated harvesting, which is applicable to both thinning and clearfell operat...

C. P. Mitchell J. B. Hudson P. G. S. Storry M. J. Brown

1993-01-01

277

Generating Functions for Multi-labeled Trees.  

PubMed

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

Czabarka, E; Erd?s, P L; Johnson, V; Moulton, V

2012-09-01

278

Adaptive significance of root grafting in trees.  

National Technical Information Service (NTIS)

Root grafting has long been observed in forest trees but the adaptive significance of this trait has not been fully explained. Various authors have proposed that root grafting between trees contributes to mechanical support by linking adjacent root system...

C. Loehle R. Jones

1988-01-01

279

Value Tree Analysis of Energy Supply Alternatives.  

National Technical Information Service (NTIS)

This study examined the use of value trees in multiattribute evaluations of energy supply alternatives. A value tree relating general values and concerns to specific value relevant attributes was constructed to compare three energy options: nuclear, coal,...

W. G. Stillwell D. Winterfeldt R. S. John

1981-01-01

280

Human Reliability Analysis Using Event Trees.  

National Technical Information Service (NTIS)

Operator behavior in a technologically complex situation such as a nuclear power plant shutdown is analyzed by making a human reliability analysis event tree (HRA event tree) of each action, breaking down each action into small elementary steps. The appli...

G. Heslinga

1983-01-01

281

Conservation of Germplasm in Forest Trees - Treesearch  

Treesearch

In themselves, trees contribute taxonomic diversity through a wealth of species, from rare to ... The actual approach to forest-tree conservation and the methods used jointly depend on ... Resource Type: Management Plans and Reports. Format ...

282

The Umdhlebe Tree of Zululand  

Microsoft Academic Search

THE word ``umdhlebe'' does not, I think, appear in Döhne's ``Zulu-Kaffir Dictionary.'' I presume it to be a derivative from the root hlaba, which Döhne interprets as denoting, among other things, the giving of pain. Some native tales of the tree will he found in part iv. of Bishop Callaway's ``Religious System of the Amazulu,'' in which it is asserted

C. H. M

1882-01-01

283

Cylindrical trees of pin fins  

Microsoft Academic Search

In this paper, we extend the constructal optimization method to cylindrical assemblies of pin fins. The assembly is arranged as a tree with one stem and many radial branches. The optimization consists of maximizing the global conductance subject to fixed total volume and amount of fin material. The length scale of the spacing between adjacent elemental fins is selected based

M. Almogbel; A. Bejan

2000-01-01

284

Transport on randomly evolving trees  

NASA Astrophysics Data System (ADS)

The time process of transport on randomly evolving trees is investigated. By introducing the notions of living and dead nodes, a model of random tree evolution is constructed which describes the spreading in time of objects corresponding to nodes. It is assumed that at t=0 the tree consists of a single living node (root), from which the evolution may begin. At a certain time instant ??0 , the root produces ??0 living nodes connected by lines to the root which becomes dead at the moment of the offspring production. In the evolution process each of the new living nodes evolves further like a root independently of the others. By using the methods of the age-dependent branching processes we derive the joint distribution function of the numbers of living and dead nodes, and determine the correlation between these node numbers as a function of time. It is proved that the correlation function converges to 3/2 independently of the distributions of ? and ? when q1?1 and t?? . Also analyzed are the stochastic properties of the end nodes; and the correlation between the numbers of living and dead end nodes is shown to change its character suddenly at the very beginning of the evolution process. The survival probability of random trees is investigated and expressions are derived for this probability.

Pál, L.

2005-11-01

285

Stable isotopes in tree rings  

Microsoft Academic Search

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

Danny McCarroll; Neil J. Loader

2004-01-01

286

Key for Trees of Iowa.  

ERIC Educational Resources Information Center

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

Coder, Kim D.; Wray, Paul H.

287

The Gift of the Tree  

NSDL National Science Digital Library

A piece of children's literature can be a powerful tool for teaching and learning science; however, it takes more than reading about a topic to qualify as "doing science." Inspired by the book, The Gift of the Tree , the author developed an in-dep

Jones, Marla W.

2009-09-01

288

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

289

Max-Min Tree Partitioning  

Microsoft Academic Search

The max-rain k-partition algorithm may be formulated as follows: Given a tree T with n edges and a nonnegative weight associated with each vertex, assign a cut to each of k distinct edges of T so as to maximize the weight of the lightest resulting connected subtree. An algorithm for this problem is presented which initially assigns all k cuts

Yehoshua Perl; Stephen R. Schach

1981-01-01

290

A Software Fault Tree Metric  

Microsoft Academic Search

Analysis of software fault trees exposes hardware and software failure events that lead to unsafe system states, and provides insight on improving safety throughout each phase of the software lifecycle. Software product lines have emerged as an effort to achieve reuse, en- hance quality, and reduce development costs of safety- critical systems. Safety-critical product lines amplify the need for improved

D. Needham; S. Jones

2006-01-01

291

Diagnosing Tree-Decomposable Circuits  

Microsoft Academic Search

This paper describes a diagnosis algorithm called structure-based abduction (SAB) which was developed in the framework of constraint networks (12). The algorithm exploits the structure of the constraint network and is most efficient for near-tree problem domains. By analyzing the structure of the problem do­ main, the performance of such algorithms can be bounded in advance. We present empir­ ical

Yousri El Fattah; Rina Dechter

1995-01-01

292

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

293

Not Just a Fall Tree  

ERIC Educational Resources Information Center

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

Miller-Hewes, Kathy A.

2004-01-01

294

Dynamic LCA queries on trees  

Microsoft Academic Search

We show how to maintain a data structure on trees which allows for the following operations, all in worst-case constant time: 1. insertion of leaves and internal nodes, 2. deletion of leaves, 3. deletion of internal nodes with only one child, 4. determining the least common ancestor of any two nodes. We also generalize the Dietz-Sleator \\

Richard Cole; Ramesh Hariharanl

1999-01-01

295

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

296

The Tree of Animal Life  

ERIC Educational Resources Information Center

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

Braude, Stan

2007-01-01

297

Estimating tree diameter class frequencies  

Microsoft Academic Search

The problem of estimating stand tables in stands with few sample points is considered. The usual point sampling estimate of trees per hectare by diameter class is examined, along with two alternative estimators: a precision-weighted composite estimator and a pseudo-Bayes estimator. Stand tables are estimated for a subject stand with each of the three estimators in a simulation experiment. Both

Edwin J. Green; Michael Clutter

2002-01-01

298

The Gift of the Tree  

ERIC Educational Resources Information Center

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

Jones, Marla Wagner

2009-01-01

299

Mycotoxins in edible tree nuts  

Microsoft Academic Search

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

Russell J. Molyneux; Noreen Mahoney; Jong H. Kim; Bruce C. Campbell

2007-01-01

300

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

301

Fault trees and imperfect coverage  

Microsoft Academic Search

A new algorithm is presented for solving the fault tree. The algorithm includes the dynamic behavior of the fault\\/error handling model but obviates the need for the Markov chain solution. As the state space is expanded in a breadth-first search (the same is done in the conversion to a Markov chain), the state's contribution to each future state is calculated

Joanne Bechta Dugan

1989-01-01

302

Finding modules in fault trees  

Microsoft Academic Search

A new method for identifying all possible modules is presented. There are two kinds of modules: (1) those whose output events are expressed by gate events, and (2) those whose output events are not expressed by gate events. The latter are logical OR or AND combinations of basic events and modules. The method requires as input only fault-tree structure data

Takehisa Kohda; Ernest J. Henley; Koichi Inoue

1989-01-01

303

Compartmentalization of Decay in Trees.  

ERIC Educational Resources Information Center

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

Shigo, Alex L.

1985-01-01

304

Conversion modelling: simulating tree stems  

Microsoft Academic Search

Profit in a competitive environment requires information to support efficient resource use in all endeavours including the forest and wood industry. The capacity to estimate value of a stand by modelling trees and simulating conversion along the whole value chain offers the potential to maximise efficiency, by enabling virtual trials of different production, processing and utilisation scenarios. Such a system

Graeme Palmer

2010-01-01

305

Transgenic Temperate Fruit Tree Rootstocks  

Microsoft Academic Search

Temperate fruit trees of the genus Malus (apple), Pyrus (pear) and Prunus (almond, apricot, sweet and sour cherry, peach, and plum) used for commercial fruit production and for backyard growers are usually grafted on clonal (asexually propagated) rootstocks. Rootstocks are used to propagate the fruiting scion onto a rooting system, to gain uniformity and precocity in fruiting portion compared to

SERGEY V DOLGOV; M-viola Hanke

306

TREE FERTILIZATION TRIALS IN ILLINOIS  

Microsoft Academic Search

The application of mineral elements to soil to stimulate the growth of established trees has been a mainstay of arborists for years. Scientific studies to justify these practices are few in number. In the past 10 years some data have become available, mostly from van de Werken in Tennessee (6, 7), Smith in Ohio (4, 5), Whitcomb in Oklahoma (3,

Dan Neely

307

Harvesting small trees for biomass  

SciTech Connect

This study evaluated precommercial, full-tree thinning of saplings and small poletimber (1-8 inches depth breadth and height) using chainsaws and modified farm tractors for skidders. To facilitate cutting large numbers of small trees (1-5 inches), the chainsaw was fitted with a felling frame. The cutter felled and manually bunched up to 145 trees/2.7 tons per productive manhour. Average production, assuming 73% efficiency, was 90 trees/1.8 tons per scheduled hour at a cost of $6.22/ton. Skidding was done by a two-wheel drive grapple skidder and a four-wheel drive farm tractor with double-drum winch. The grapple skidder produced 3.8 tons per scheduled hour at a cost of $8.25 per ton, assuming a 75% utilization rate. The cable skidder produced 4 tons per scheduled hour at a cost of $7.00/ton; preset chokers increased production to 4.7 tons/hour at a cost of $5.96. The key to production was a modified herringbone pattern of corridors which facilitated skidder access to the wood. The weakest link in the operation was the difficult, labor-intensive work of felling and bunching. 14 references.

Hoffman, B.F.

1986-02-01

308

Tree spanners on chordal graphs: complexity andalgorithms  

Microsoft Academic Search

A tree t-spanner T in a graph G is a spanning tree of G such that the distance in T between every pair of vertices is at most t times their distance in G. The TREE t-SPANNER problem asks whether a graph admits a tree t-spanner, given t. We substantially strengthen the hardness result of Cai andCorneil (SIAM J. Discrete

Andreas Brandst; Feodor F. Dragan; Bang Le

309

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

310

Diversity of Endophytic Bacteria in Forest Trees  

Microsoft Academic Search

\\u000a A group of studies on the diversity of endophytic bacteria in forest trees is presented in terms of host plant species variety\\u000a and the number of reports. Many host tree species are underrepresented in these studies: Trees in the tropics as well as some\\u000a important temperate tree species, such as those belonging to the genera of Alnus and Fagus, have

Hironari Izumi

311

A Bayes Evaluation Criterion for Decision Trees  

Microsoft Academic Search

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

Nicolas Voisine; Marc Boullé; Carine Hue

2009-01-01

312

Isoprene emission from Indian trees  

NASA Astrophysics Data System (ADS)

Isoprene is the most dominant non-methane volatile organic compound (NMVOC) emitted by plants. NMVOCs play an important role in regulating the composition of atmospheric trace gases including global concentration of tropospheric ozone. Our present knowledge about NMVOCs emission is mainly from studies on temperate tree species. So far information on biogenic NMVOCs emission from tropical tree species is limited. In this study, isoprene emission rates from 40 tropical Indian tree species belonging to 33 genera and 17 families were measured for the first time using a dynamic flow through enclosure chamber technique. The isoprene emission rate from plants (30°C and PAR 1000 ?molm-2s-1) ranged from undetectable to 81.5 ?g g-1 h-1 and values were found to be comparable with other studies on tropical tree species. Tree species screened for isoprene emission in the present study may be grouped into the four categories, proposed by [2001], namely, 18 species were negligible or BDL isoprene emitting (<1 ?g g-1 h-1), 6 species were low emitting (1 ? to <10 ?g g-1 h-1), 5 species were moderate emitting (10? to <25 ?g g-1 h-1), and 11 species were high isoprene emitting (?25 ?g g-1 h-1). Maximum isoprene emission rate (81.5 ?g g-1 h-1) was observed in the case of Dalbergia sissoo Linn. It was interesting to find that Citrus limon Linn., Citrus reticulata Linn., Citrus sinensis Linn., Grevillea robusta A. Cunn., and Morus alba Linn., which were earlier reported as BDL or non isoprene emitters in US [, 1998; , 2001] were found to be appreciably high isoprene emitters (0.61-21.60 ?g g-1 h-1) in the present study.

Varshney, C. K.; Singh, Abhai Pratap

2003-12-01

313

Approximating Hexagonal Steiner Minimal Trees by Fast Optimal Layout of Minimum Spanning Trees  

Microsoft Academic Search

We study algorithms for approximating a Steiner minimal tree interconnecting n points under hexagonal routing. We prove that: (1) every minimum spanning tree is separable; (2) a minimum spanning tree with maximum node degree no more than 5 can be computed in O (n log n) time; (3) an optimal L-shaped layout of a given minimum spanning tree can be

Guo-hui Lin; Guoliang Xue; Defang Zhou

1999-01-01

314

Combining dynamic fault trees and event trees for probabilistic risk assessment  

Microsoft Academic Search

As system analysis methodologies, both event tree analysis (ETA) and fault tree analysis (FTA) are used in probabilistic risk assessment (PRA), especially in identifying system interrelationships due to shared events. Although there are differences between them, ETA and FTA, are so closely linked that fault trees (FT) are often used to quantify system events that are part of event tree

Hong Xu; Joanne Bechta Dugan

2004-01-01

315

Relation between individual tree mortality and tree characteristics in a polluted and non-polluted environment.  

PubMed

Data on individual tree mortality in relatively healthy (Berezinskiy biosphere reserve) and damaged (surroundings of the mineral fertilizer plant 'Achema') even-aged Scots pine (Pinus sylvestris L.) stands are presented. Tree size and competition intensity were found to be the most significant predictors of individual tree mortality in all age groups of the relatively healthy Scots pine stands, however, an essential reduction in the closeness of relations between the tree mortality rate and these variables was determined with the aging of stands. An exponential decrease in tree mortality probability with an increase of tree size is characteristic for trees suffering different competition intensity, however, this decrease becomes much more pronounced as the competition pressure increases. The relations of different tree and stand variables with tree mortality probability have been found to become much weaker in the polluted environment. An exponential increase in tree mortality probability with an increase of crown defoliation was characteristic of damaged Scots pine stands, however, the rate of the increase was different in different age and diameter classes. The impact of crown defoliation on tree mortality rate increased with the aging of stands. At the same defoliation level, individual tree mortality probability was much higher for smaller suppressed trees, however, a relative increase in tree mortality probability along with an increase of crown defoliation was more pronounced for dominant trees. Conclusion: a higher mortality of damaged (defoliated) trees should be considered while assessing losses in forest productivity in a polluted environment. PMID:16738768

Juknys, Romualdas; Vencloviene, Jone; Jurkonis, Nerijus; Bartkevicius, Edmundas; Sepetiene, Janina

2006-06-01

316

The relationship between the 0-tree and other trees in a linear nongroup cellular automata ?y  

Microsoft Academic Search

We investigate the relationship between the 0-tree and other trees in linear nongroup cellular automata. And we show that given a 0-basic path of 0-tree and a nonzero attractor fi of a multiple attractor linear cellulara automata with two predecessor we construct an fi-tree of that multiple attractor linear cellular automata.

Sung-Jin Cho

317

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

318

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

Microsoft Academic Search

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

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

1997-01-01

319

Nitrogen Fixing Trees for Fodder Production: A Field Manual.  

National Technical Information Service (NTIS)

Contents: Nitrogen Fixing trees for fodder production; Fodder tree establishment; Selecting species of nitrogen fixing fodder trees; Fodder production systems; Nutritive value and animal production from fodder trees; Problems and constraints with fodder t...

J. M. Roshetko R. C. Gutteridge

1996-01-01

320

Tree rings, carbon dioxide, and climatic change  

Microsoft Academic Search

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

GORDON C. JACOBY; ROSANNE D. D'ARRIGO

1997-01-01

321

On the topology of multicast trees  

Microsoft Academic Search

The benefit derived from using multicast is seemingly dependent upon the shape of the distribution tree. In this paper, we attempt to accurately model interdomain multicast trees. We measure a number of key parameters, such as depth, degree frequency, and average degree, for a number of real and synthetic data sets. We find that interdomain multicast trees actually do share

Robert C. Chalmers; Kevin C. Almeroth

2003-01-01

322

Scalable look-ahead linear regression trees  

Microsoft Academic Search

Most decision tree algorithms base their splitting decisions on a piecewise constant model. Often these splitting algorithms are extrapolated to trees with non-constant models at the leaf nodes. The motivation behind Look-ahead Linear Regression Trees (LLRT) is that out of all the methods proposed to date, there has been no scalable approach to exhaustively evaluate all possible models in the

David S. Vogel; Ognian Asparouhov; Tobias Scheffer

2007-01-01

323

Art-directing Disney's Tangled procedural trees  

Microsoft Academic Search

Creating stylized trees with hundreds of thousands of leaves is typically a painstaking task that requires hours of artist time. In Walt Disney's animated feature film Tangled, we faced the challenge of populating dense forests with animated trees on which artists could quickly iterate to meet an art-directed look. We designed a system of authoring trees based around a language

Arthur Shek; Dylan Lacewell; Andrew Selle; Daniel Teece; Tom Thompson

2010-01-01

324

Optimal Decision Trees on Simplicial Complexes  

Microsoft Academic Search

We consider topological aspects of decision trees on simplicial complexes, con- centrating on how to use decision trees as a tool in topological combinatorics. By Robin Forman's discrete Morse theory, the number of evasive faces of a given di- mension i with respect to a decision tree on a simplicial complex is greater than or equal to the ith reduced

Jakob Jonsson

2005-01-01

325

Effect of surfactants in water treeing  

Microsoft Academic Search

The influence of surfactants on water tree initiation and growth was studied using the water needle method in polyethylene specimens. According to their nature (ionic or anionic) and concentration, they may promote or reduce the water treeing phenomenon. Anionic surfactants in solution in water significantly influence the initiation and growth of water trees in polyethylene. At low concentration-below the CMC

J. Rouviere; N. Kamenka; M. Lindheimer; Y. Poggi; J. C. Filippini

1988-01-01

326

Formal methodology for fault tree construction  

Microsoft Academic Search

A model is presented for formulating the Boolean failure logic, cailed ; the fault tree, for electrical systems from associated schematic diagrams and ; system-independent component information. The model is developed in detail for ; electrical systems, while its implication and terminology extend to all fault ; tree construction. The methodology is verified as formal by fault trees ; constructed

Fussell

1973-01-01

327

Diagnostic expert systems from dynamic fault trees  

Microsoft Academic Search

A methodology for developing a diagnostic map for systems that can be analyzed via a dynamic fault tree is proposed in this paper. This paper shows how to automatically design a diagnostic decision tree from a dynamic fault tree used for reliability analysis. In particular the methodology makes use of Markov chains since they are mathematical models used for reliability

Tariq Assaf; Joanne Bechta Dugan

2004-01-01

328

Paths in m-ary interval trees  

Microsoft Academic Search

We introduce the m-ary interval tree, a random structure that underlies interval division and simultaneous parking problems. Certain significant paths in the m-ary interval trees are considered. When appropriately normed, the length of these paths are shown to converge in distribution to a normal random variable. The work extends the study of incomplete binary interval trees in Itoh and Mahmoud

Mehri Javanian; Hosam M. Mahmoud; Mohammad Vahidi-asl

2004-01-01

329

A Polynomial Kernel for Multicut in Trees  

Microsoft Academic Search

The MULTICUT IN TREES problem consists in deciding, given a tree, a set of requests (i.e. paths in the tree) and an integer k, whether there exists a set of k edges cutting all the requests. This problem was shown to be FPT by Guo and Niedermeyer in (10). They also provided an exponential kernel. They asked whether this problem

Nicolas Bousquet; Jean Daligault; Stéphan Thomassé; Anders Yeo

2009-01-01

330

The Ordered Core Based Tree Protocol  

Microsoft Academic Search

This paper presents a new protocol, the Ordered Core Based Tree(OCBT) protocol, which remedies several shortcomings of the CoreBased Tree (CBT) multicast protocol. We show that the CBT protocolcan form loops during periods of routing instability, and that itcan consistently fail to build a connected multicast tree, even whenthe underlying routing is stable. The OCBT protocol provably eliminatesthese deficiencies and

Clay Shields; J. J. Garcia-luna-aceves

1997-01-01

331

Tree propagation and the effects of barriers  

Microsoft Academic Search

The authors describe impulse experiments using alternating voltages and the explosion effect simulated to create synthetic tree channels. It is confirmed that trees propagate by fast fracture triggered by the explosive effect of localized intrinsic breakdown at points of electrical stress concentration. The interaction between barriers and advancing tree channels is determined by the barrier's adhesive bond to the surrounding

D. W. Auckland; S. M. F. Kabir; B. R. Varlow

1989-01-01

332

Logics for Unranked Trees: An Overview  

Microsoft Academic Search

Labeled unranked trees are used as a model of XML documents, and logical languages for them have been studied actively over the past several years. Such logics have different purposes: some are better suited for extracting data, some for expressing navigational properties, and some make it easy to relate complex properties of trees to the existence of tree automat a

Leonid Libkin

2005-01-01

333

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

334

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

335

Horizontal subsea trees allow frequent deepwater workovers  

Microsoft Academic Search

Horizontal subsea wellheads have found application in the Liuhua oil field in the South China Sea. These trees allow installation and retrieval of downhole equipment through the tree without having to disturb the tree or its external connections to flow lines, service lines, or control umbilicals. This access to the well is important because the Liuhua wells will be produced

M. Krenek; G. Hall; W. Z. Sheng

1995-01-01

336

Constrained Cascade Generalization of Decision Trees  

Microsoft Academic Search

While decision tree techniques have been widely used in classification applications, a shortcoming of many decision tree inducers is that they do not learn intermediate concepts, i.e., at each node, only one of the original features is involved in the branching decision. Combining other classification methods, which learn intermediate concepts, with decision tree inducers can produce more flexible decision boundaries

Huimin Zhao; Sudha Ram

2004-01-01

337

Replacing suffix trees with enhanced suffix arrays  

Microsoft Academic Search

The suffix tree is one of the most important data structures in string processing and comparative genomics. However, the space consumption of the suffix tree is a bottleneck in large scale applica- tions such as genome analysis. In this article, we will overcome this obstacle. We will show how every algorithm that uses a suffix tree as data structure can

Mohamed Ibrahim Abouelhoda; Stefan Kurtz; Enno Ohlebusch

2004-01-01

338

Suffix Binary Search Trees and Suffix Arrays  

Microsoft Academic Search

Suffix arrays and suffix binary search trees are two data structuresthat have been proposed as alternatives to the classical suffix tree tofacilitate efficient on-line string searching. Here, we explore the relationshipbetween these two structures. In particular, we present analternative view of a suffix array, with its auxiliary information, as aperfectly balanced suffix binary search tree, and describe an elegantand efficient

Robert W. Irving; Lorna Love

2001-01-01

339

Constructing Big Trees from Short Sequences  

Microsoft Academic Search

. The construction of evolutionary trees is a fundamentalproblem in biology, and yet methods for reconstructing evolutionary treesare not reliable when it comes to inferring accurate topologies of largedivergent evolutionary trees from realistic length sequences. We addressthis problem and present a new polynomial time algorithm for reconstructingevolutionary trees called the Short Quartets Method which isconsistent and which has greater statistical

Péter L. Erdös; Michael A. Steel; László A. Székely; Tandy Warnow

1997-01-01

340

Controlled Flux Results in Stable Decision Trees  

Microsoft Academic Search

This work deals with stability in incremental induction of decision trees. Stability problems arise when an induction algorithm must revise a decision tree very often and tree oscillations between similar concepts decrease learning speed. We introduce a heuristic to tackle this problem and an algorithm that uses this heuristic, and we provide theoretical and experimental backing to justify it.

Dimitrios Kalles; Athanassios Papagelis

1999-01-01

341

Rule set reduction in fuzzy decision trees  

Microsoft Academic Search

The ID3 algorithm forms the basis for many decision trees' algorithms and programs. Trees produced by this algorithm are known to be very sensitive to small changes in attribute values. Fuzzy ID3 is an extension of ID3; it integrates fuzzy set theory and fuzzy logic with ID3. This integration reduces the sensitivity of the produced decision trees to small changes

N. M. Abu-halaweh; Robert W. Harrison

2009-01-01

342

Laccase versus laccase-like multi-copper oxidase: a comparative study of similar enzymes with diverse substrate spectra.  

PubMed

Laccases (EC 1.10.3.2) are multi-copper oxidases that catalyse the one-electron oxidation of a broad range of compounds including substituted phenols, arylamines and aromatic thiols to the corresponding radicals. Owing to their broad substrate range, copper-containing laccases are versatile biocatalysts, capable of oxidizing numerous natural and non-natural industry-relevant compounds, with water as the sole by-product. In the present study, 10 of the 11 multi-copper oxidases, hitherto considered to be laccases, from fungi, plant and bacterial origin were compared. A substrate screen of 91 natural and non-natural compounds was recorded and revealed a fairly broad but distinctive substrate spectrum amongst the enzymes. Even though the enzymes share conserved active site residues we found that the substrate ranges of the individual enzymes varied considerably. The EC classification is based on the type of chemical reaction performed and the actual name of the enzyme often refers to the physiological substrate. However, for the enzymes studied in this work such classification is not feasible, even more so as their prime substrates or natural functions are mainly unknown. The classification of multi-copper oxidases assigned as laccases remains a challenge. For the sake of simplicity we propose to introduce the term "laccase-like multi-copper oxidase" (LMCO) in addition to the term laccase that we use exclusively for the enzyme originally identified from the sap of the lacquer tree Rhus vernicifera. PMID:23755261

Reiss, Renate; Ihssen, Julian; Richter, Michael; Eichhorn, Eric; Schilling, Boris; Thöny-Meyer, Linda

2013-06-03

343

Sleeping tree choice by Bwindi chimpanzees.  

PubMed

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

Stanford, Craig B; O'Malley, Robert C

2008-07-01

344

A Decidable Characterization of Locally Testable Tree Languages  

Microsoft Academic Search

A regular tree language L is locally testable if membership of a tree into L depends only on the presence or absence of some fix set of neighborhoods in the tree. In this paper we show that it is decidable whether a regular tree language is locally testable. The decidability is shown for ranked trees and for unranked unordered trees.

Luc Segoufin

2009-01-01

345

A decidable characterization of locally testable tree languages  

Microsoft Academic Search

A regular tree language L is locally testable if membership of a tree in L depends only on the presence or absence of some fix set of neighborhoods in the tree. In this paper we show that it is decidable whether a regular tree language is locally testable. The decidability is shown for ranked trees and for unranked unordered trees.

Luc Segoufin

2011-01-01

346

Hollows in jarrah ( Eucalyptus marginata) and marri ( Corymbia calophylla) trees  

Microsoft Academic Search

One hundred and fifty-four jarrah (Eucalyptus marginata) and 85 marri (Corymbiacalophylla) trees were measured and assessed, and the numbers and sizes of hollows in these trees were determined by destructive sampling; 665 hollows were located and measured. The relationship between tree diameter and tree age was determined from counts of annual growth rings on 162 of these trees. Large trees

K. R Whitford

2002-01-01

347

Inference of fitness from genealogical trees  

NASA Astrophysics Data System (ADS)

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

Vucelja, Marija; Dayarian, Adel; Shraiman, Boris

2013-03-01

348

Hyperdominance in the Amazonian tree flora.  

PubMed

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

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

2013-10-18

349

Tree decline in North America.  

PubMed

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

Chevone, B I; Linzon, S N

1988-01-01

350

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

351

Integral trees of diameter 6  

Microsoft Academic Search

A graph G is called integral if all eigenvalues of its adjacency matrix A(G) are integers. In this paper, the trees T(p,q)•T(r,m,t) and K1,s•T(p,q)•T(r,m,t) of diameter 6 are defined. We determine their characteristic polynomials. We also obtain for the first time sufficient and conditions for them to be integral. To do so, we use number theory and apply a computer

Ligong Wang; Hajo Broersma; Cornelis Hoede; Xueliang Li; Georg Still

2007-01-01

352

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

353

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

354

Tree climbing and human evolution.  

PubMed

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

2012-12-31

355

Dendrochemistry: Seeing the forest through the trees  

NASA Astrophysics Data System (ADS)

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

Hauck, Danielle K.

356

Extractability and biological activity of tannins from various tree leaves determined by chemical and biological assays as affected by drying procedure  

Microsoft Academic Search

Leaf samples of Juglans regia (walnut), Rhus typhina (sumach), Aesculus hippocastanum (chestnut) and Salix alba (willow) were either freeze dried or oven dried and the amount of tannins was determined by two chemical assays (Folin Ciocalteau and ferric chloride method). In addition, the biological activity of these tannins was determined by their protein precipitation capacity and by a bioassay based

S. Muetzel; K. Becker

2006-01-01

357

FEP 4.16. Fault-tree, Event tree, & P&ID Editors  

SciTech Connect

FEP4.16 is a program developed to provide a common access to a suite of graphical tools developed for performing Probabilistic Risk Assessment (PRA). These tools include the graphical event tree, fault tree, and P and ID editors. The event tree editor allows the analyst to construct and modify graphical event trees. The fault tree editor allows the user to construct and modify graphical fault trees. The P and ID editor allows the user to construct and modify plant drawings. These drawings can then be used to document the modeling used in a PRA.

Russell, K.D. [EG and G Idaho Inc., Idaho Falls, ID (United States)

1994-02-01

358

Fault Tree, Event Tree, and Piping and Instrumentation Diagram (FEP) editors, Version 4. 0  

SciTech Connect

The Fault Tree, Event Tree, and Piping Instrumentation Diagram (FEP) editors allow the user to graphically build and edit fault trees, event trees, and piping instrumentation diagrams (P IDs). The software is designed to enable the use of graphical-based editors found in the Integrated Reliability and Risk Assessment System (IRRAS). FEP is made up of three separate editors (Fault Tree, Event Tree, and Piping Instrumentation Diagram) and a utility module. This reference manual provides a screen-by-screen walkthrough of the entire FEP System.

McKay, M.K.; Skinner, N.L.; Wood, S.T. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

1992-05-01

359

Local Frame Junction Trees in SLAM  

NASA Astrophysics Data System (ADS)

Junction trees (JT) is a general purpose tool for exact inference on graphical models. Many of the existing algorithms for building junction trees require a fixed static graphical model. The construction process is not unique, finding the one with the best computational structure (smallest clique size) is also a hard problem. For large scale inference problems, such as Geo-referencing using triangular geodetic networks or equivalent, the simultaneous localization and mapping (SLAM) problem in robotics pose some challenges to junction tree applications. Incremental junction tree techniques for dynamic graphical models prescribe heuristic methods for growing the tree structure, and are applicable to large scale graphical models. Of concern are the proliferative widening of the tree, which makes message passing expensive. In the context of SLAM we present a new apporach that exploits the local frame dependence of novel observation variables.

Kuehnel, Frank O.

2005-11-01

360

The Biases of Decision Tree Pruning Strategies  

Microsoft Academic Search

Post pruning of decision trees has been a successful approach in many real-world experiments, but over all possible concepts it does not bring any inherent improvement to an algorithm's performance. This work explores how a PAC-proven decision tree learning algorithm fares in comparison with two variants of the normal top-down induction of decision trees. The algorithm does not prune its

Tapio Elomaa

1999-01-01

361

A geometric approach to tree shape statistics  

Microsoft Academic Search

This article presents a new way to understand the descriptive ability of tree\\u000ashape statistics. Where before tree shape statistics were chosen by their\\u000aability to distinguish between macroevolutionary models, the ``resolution''\\u000apresented in this paper quantifies the ability of a statistic to differentiate\\u000abetween similar and different trees. We term this a ``geometric'' approach to\\u000adifferentiate it from the

Frederick A. Matsen

2005-01-01

362

ENERGY CONSERVATION POTENTIAL OF URBAN TREE PLANTING  

Microsoft Academic Search

Findings from monitoring and computer simu- lation studies indicate that trees can be a cost-effective energy conservation measure for some electric utilities. Our simula- tions suggest that a single 25-ft tall tree can reduce annual heating and cooling costs of a typical residence by 8 to 12 percent ($10-25). Assuming annual savings of $10 per household, a nationwide residential tree

E. Gregory McPherson; Rowan A. Rowntree

1993-01-01

363

Ningxia decision on grass, tree planting  

SciTech Connect

This article reports on plans to plant grass and trees, develop animal husbandry, and transform areas in northwestern China which are subject to drought. Proposed governmental measures include an educational program to show the relationship between grass and tree planting and developing animal husbandry and grain production; a mobilization of the people in the grass and tree planting campaign; the strengthening of scientific and technical guidance; and the creation of cadre responsibility systems.

Not Available

1983-10-15

364

Enumeration of spanning trees on Apollonian networks  

NASA Astrophysics Data System (ADS)

In this paper we study the problem of enumerating spanning trees on Apollonian networks and obtain an exact expression for the number of spanning trees, which is relevant to some dynamical characteristics of networks, such as reliability, synchronization and random walks. In addition, we compare the entropy of spanning trees on our networks with the other fractal networks, and find that the entropy of our networks is the highest among the studied fractal networks.

Zhang, Jingyuan; Sun, Weigang; Xu, Guanghui

2013-09-01

365

Deciding Equivalence of Finite Tree Automata  

Microsoft Academic Search

We show:for mJe~j constant m it can be decided in polynomial time whether or not two m-ambiguous finite tree automata are equivalent. In general, inequiva- lence for finite tree automata is DEXPTIfdE-complete v).r.t, logspace reductions, and PSPACE-complete w.r.t, logspace reductions, if the automata in question are supposed to accept only finite languages. For finite tree automata uith coefficients in a

Helmut Seidl

1989-01-01

366

Public Reactions to New Street Tree Planting  

Microsoft Academic Search

MillionTreesNYC, which has the goal of planting one million trees in New York City by 2017, is intended to make New York City a greener, more sustainable city and is part of the Mayor’s comprehensive long term strategic plan, PlaNYC. Through planting a tree at every suitable sidewalk location in the city, the City of New York is transforming blocks

Ruth A. Rae; Gabriel Simon; Jessie Braden

2011-01-01

367

Present state of whole-tree harvesting  

SciTech Connect

The utilization of whole-tree chips as an energy source has resulted in an increase in production of 12.4 M tons in 1975 from 483 whole-tree chippers to 18.7 M tons in 1979 from 732 machines. The whole-tree harvesting system, while it is the costliest method of producing chips in terms of capital investment, is by far the most productive method on a man-day basis.

Plummer, G.M.

1981-04-01

368

Present state of whole-tree harvesting  

Microsoft Academic Search

The utilization of whole-tree chips as an energy source has resulted in an increase in production of 12.4 M tons in 1975 from 483 whole-tree chippers to 18.7 M tons in 1979 from 732 machines. The whole-tree harvesting system, while it is the costliest method of producing chips in terms of capital investment, is by far the most productive method

Plummer

1981-01-01

369

On the diameters of spanning trees  

Microsoft Academic Search

The tree-diameter set of a connected graphGis the set of all diameters of the spanning trees ofG, written in the increasing order. A relation between the consecutive elements of this set is obtained and it is shown to be the best possible. A sufficient condition for a set to be a feasible tree-diameter set is given and this solves a

V. Sankaran; V. Krishnamoorthy

1985-01-01

370

Aspergillus on tree nuts: incidence and associations  

Microsoft Academic Search

California exports tree nuts to countries where they face stringent standards for aflatoxin contamination. Trade concerns\\u000a have stimulated efforts to eliminate aflatoxins and Aspergillus flavus from almonds, pistachios and walnuts. Incidence of fungi on tree nuts and associations among fungi on tree nuts were studied.\\u000a Eleven hundred pistachios, almonds, walnuts and brazil nuts without visible insect damage were plated on

Paul Bayman; James L. Baker; Noreen E. Mahoney

2002-01-01

371

Teaching Through Trade Books: Talking Trees  

NSDL National Science Digital Library

Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. The activities in this month's Teaching Through Trade Books column help students 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 height of a tree.

Tolman, Marvin

2005-02-01

372

Reusable components in decision tree induction algorithms  

Microsoft Academic Search

We propose a generic decision tree framework that supports reusable components design. The proposed generic decision tree\\u000a framework consists of several sub-problems which were recognized by analyzing well-known decision tree induction algorithms,\\u000a namely ID3, C4.5, CART, CHAID, QUEST, GUIDE, CRUISE, and CTREE. We identified reusable components in these algorithms as well\\u000a as in several of their partial improvements that can

Milija Suknovic; Boris Delibasic; Milos Jovanovic; Milan Vukicevic; Dragana Becejski-Vujaklija; Zoran Obradovic

2012-01-01

373

Cutting down trees with a Markov chainsaw  

Microsoft Academic Search

We provide simplified proofs for the asymptotic distribution of the number of cuts required to cut down a Galton--Watson tree with critical, finite-variance offspring distribution, conditioned to have total progeny n. Our proof is based on a coupling which yields a precise, non-asymptotic distributional result for the case of uniformly random rooted labeled trees (or, equivalently, Poisson Galton--Watson trees conditioned

Louigi Addario-Berry; Nicolas Broutin; Cecilia Holmgren

2011-01-01

374

Learning probabilistic models of tree edit distance  

Microsoft Academic Search

Nowadays, there is a growing interest in machine learning and pattern recognition for tree-structured data. Trees actually provide a suitable structural representation to deal with complex tasks such as web information extraction, RNA secondary structure prediction, computer music, or conversion of semi-structured data (e.g. XML documents). Many applications in these domains require the calculation of similarities over pairs of trees.

Marc Bernard; Laurent Boyer; Amaury Habrard; Marc Sebban

2008-01-01

375

The Tree of Animal Life  

NSDL National Science Digital Library

The Tree of Animal Life activity is a simple, sorting exercise that can help them see a bigger picture. The activity sets the stage for learning about animal taxonomy and introduces the characteristics of various animal groups in a general way. Though the activity doesn't teach about each animal group's characteristics in great detail, the process of sorting of atypical examples (e.g., bat, octopus) does spark interesting discussions among students on the differences between animals and how scientists classify them. I've conducted the activity with students of various ages.

Braude, Stan

2007-09-01

376

Branching Programs for Tree Evaluation  

Microsoft Academic Search

The problem FThd(k)FT^{h}_{d}(k) consists in computing the value in [k]?=?{1,...,k} taken by the root of a balanced d-ary tree of height h whose internal nodes are labelled with d-ary functions on [k] and whose leaves are labelled with elements of [k]. We propose FThd(k){FT^{h}_{d}(k)} as a good candidate for witnessing \\u000a\\u000a\\u000a\\u000a\\u000a\\u000aL \\\\subsetneqLogDCFL{\\\\mathbf{L}} \\\\subsetneq{\\\\mathbf{LogDCFL}}. We observe that the latter would follow

Mark Braverman; Stephen A. Cook; Pierre McKenzie; Rahul Santhanam; Dustin Wehr

2009-01-01

377

GRAFTED - GRaphical Fault Tree EDitor: A Fault Tree Description Program for Target Vulnerability/Survivability Analysis.  

National Technical Information Service (NTIS)

A computer program GRAFTED, 'GRAphical Fault Tree EDitor', has been written to simplify data entry and modification of component fault tree descriptions (FTD) used in military platform vulnerability/survivability analysis procedures. GRAFTED utilizes a un...

F. J. Tkalcevic N. M. Burman

1992-01-01

378

On Tree-Constrained Matchings and Generalizations  

Microsoft Academic Search

\\u000a We consider the following Tree-Constrained Bipartite Matching problem: Given two rooted trees T\\u000a 1?=?(V\\u000a 1,E\\u000a 1), T\\u000a 2?=?(V\\u000a 2,E\\u000a 2) and a weight function w: V\\u000a 1×V\\u000a 2 ???+?, find a maximum weight matching M\\\\mathcal{M} between nodes of the two trees, such that none of the matched nodes is an ancestor of another matched node in either of the\\u000a trees.

Stefan Canzar; Khaled Elbassioni; Gunnar W. Klau; Julián Mestre

2011-01-01

379

Magnetic Measurements on Maple and Sequoia Trees  

Microsoft Academic Search

\\u000a Magnetic measurements of soil and tree bark adjacent to a busy highway revealed a significant variation in the concentration\\u000a of magnetic particles with distance from the highway. Furthermore, forest-facing tree-bark contains significantly more magnetic\\u000a particles than road-facing tree-bark. Magnetic particles were detected both on the bark of the maple trees and in the first\\u000a centimeter of the soil cover (O\\/A

Gunther Kletetschka

380

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

381

Horizontal subsea trees allow frequent deepwater workovers  

SciTech Connect

Horizontal subsea wellheads have found application in the Liuhua oil field in the South China Sea. These trees allow installation and retrieval of downhole equipment through the tree without having to disturb the tree or its external connections to flow lines, service lines, or control umbilicals. This access to the well is important because the Liuhua wells will be produced with electrical submersible pumps (ESPs), which may have relatively short intervals between maintenance, leading to frequent well work. The wells will be completed subsea in about 300 m of water. The large bore, horizontal trees allow all downhole equipment to be pulled without removal of the subsea tree. This wellhead configuration also provides well control and vertical access to downhole equipment through a conventional marine drilling riser and subsea blowout preventer (BOP), eliminating the need for costly specialized completion risers. Another benefit of the horizontal tree is its extremely compact profile with a low number of valves for well control. Valve size and spacing are decoupled from the size and bore spacing of the tubing hanger. The tree`s low profile geometry reduces costs of manufacturing the tree and framework and optimize load transfer to the wellhead.

Krenek, M. [FMC Wellhead Equipment Division, Houston, TX (United States); Hall, G. [Amoco Corp., Shekou (China); Sheng, W.Z. [China Offshore Nanhai East Corp., Shekou (China)

1995-05-01

382

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

PubMed

Although savanna trees and forest trees are thought to represent distinct functional groups with different effects on ecosystem processes, few empirical studies have examined these effects. In particular, it remains unclear if savanna and forest trees differ in their ability to coexist with understory plants, which comprise the majority of plant diversity in most savannas. We used structural equation modeling (SEM) and data from 157 sites across three locations in the southeastern United States to understand the effects of broadleaf savanna trees, broadleaf forest trees, and pine trees on savanna understory plant communities. After accounting for underlying gradients in fire frequency and soil moisture, abundances (i.e., basal area and stem density) of forest trees and pines, but not savanna trees, were negatively correlated with the cover and density (i.e., local-scale species richness) of C4 graminoid species, a defining savanna understory functional group that is linked to ecosystem flammability. In analyses of the full understory community, abundances of trees from all functional groups were negatively correlated with species density and cover. For both the C4 and full communities, fire frequency promoted understory plants directly, and indirectly by limiting forest tree abundance. There was little indirect influence of fire on the understory mediated through savanna trees and pines, which are morefire tolerant than forest trees. We conclude that tree functional identity is an important factor that influences overstory tree relationships with savanna understory plant communities. In particular, distinct relationships between trees and C4 graminoids have implications for grass-tree coexistence and vegetation-fire feedbacks that maintain savanna environments and their associated understory plant diversity. PMID:23691661

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

2013-02-01

383

An Experimental Analysis of Consensus Tree Algorithms for Large-Scale Tree Collections  

Microsoft Academic Search

Consensus trees are a popular approach for summarizing the shared evolutionary relationships in a collection of trees. Many\\u000a popular techniques such as Bayesian analyses produce results that can contain tens of thousands of trees to summarize. We\\u000a develop a fast consensus algorithm called HashCS to construct large-scale consensus trees. We perform an extensive empirical\\u000a study for comparing the performance of

Seung-jin Sul; Tiffani L. Williams

2009-01-01

384

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

Microsoft Academic Search

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

Roel Jacobus Wilhelmus Brienen

2005-01-01

385

Cerebral Vascular Tree Matching of 3DRA Data Based on Tree Edit Distance  

Microsoft Academic Search

In this paper, we present a novel approach to matching cere- bral vascular trees obtained from 3D-RA data-sets based on minimiza- tion of tree edit distance. Our approach is fully automatic which requires zero human intervention. Tree edit distance is a term used in the fleld of theoretical computer science to describe the similarity between two la- beled trees. In

Tommy W. H. Tang; Albert C. S. Chung

2006-01-01

386

Fast alignment of fragmentation trees  

PubMed Central

Motivation: Mass spectrometry allows sensitive, automated and high-throughput analysis of small molecules such as metabolites. One major bottleneck in metabolomics is the identification of ‘unknown’ small molecules not in any database. Recently, fragmentation tree alignments have been introduced for the automated comparison of the fragmentation patterns of small molecules. Fragmentation pattern similarities are strongly correlated with the chemical similarity of the molecules, and allow us to cluster compounds based solely on their fragmentation patterns. Results: Aligning fragmentation trees is computationally hard. Nevertheless, we present three exact algorithms for the problem: a dynamic programming (DP) algorithm, a sparse variant of the DP, and an Integer Linear Program (ILP). Evaluation of our methods on three different datasets showed that thousands of alignments can be computed in a matter of minutes using DP, even for ‘challenging’ instances. Running times of the sparse DP were an order of magnitude better than for the classical DP. The ILP was clearly outperformed by both DP approaches. We also found that for both DP algorithms, computing the 1% slowest alignments required as much time as computing the 99% fastest. Contact: sebastian.boecker@uni-jena.de

Hufsky, Franziska; Duhrkop, Kai; Rasche, Florian; Chimani, Markus; Bocker, Sebastian

2012-01-01

387

BLACK BEAR MARK TREES IN THE SMOKY MOUNTAINS  

Microsoft Academic Search

A total of 691 black bear (Ursus americanus) mark trees were located in the Great Smoky Mountains National Park. Mark trees along preselected index trails were tagged, physiognomic parameters around the trees measured, and characteristics of the tree and mark recorded. Trees along the index trails were reobserved periodically from April to December 1976-77 (bi- weekly between May and October)

TOM L. BURST; MICHAEL R. PELTON

388

Development of automatic fault tree synthesis system using decision matrix  

Microsoft Academic Search

Fault trees synthesis, the basis for fault tree analysis (FTA), serves as a powerful tool for risk analysis. It has become a trend to accomplish computer-assisted fault tree synthesis in the field of system safety engineering because conventional manual construction of fault trees can be extremely time-consuming and vulnerable to human errors. This paper expounds upon a fault tree synthesis

Zong-Xiao Yang; Yan-Yi Zheng; Jin-Xue Xue

2009-01-01

389

Decomposing an Nary relation into a tree of binary relations  

Microsoft Academic Search

We present an efficient algorithm for decomposing an n-ary relation into a tree of binary relations, and provide an efficient test for checking whether or not the tree formed represents the relation. If there exists a tree-decomposition, the algorithm is guaranteed to find one, otherwise, the tree generated will fail the test, then indicating that no tree decomposition exist. The

Rina Dechter

1987-01-01

390

HOUSEHOLDER EVALUATIONS OF STREET TREES IN A CHICAGO SUBURB  

Microsoft Academic Search

Residents of Downers Grave, Illinois were sur- veyed about the street trees in front of their homes and in their neighborhoods. Householders' perceptions of benefits and annoyances of eight street tree species and of five types of neighborhood tree populations were compared. The survey assessed residents' satisfaction with the benefits and annoy- ances they receive from the trees; the trees'

Herbert W. Schroeder; Steven R. Ruffolo

391

Electrical treeing and the associated PD characteristics in LDPE nanocomposites  

Microsoft Academic Search

Treeing in low density polyethylene (LDPE) filled with alumina nanocomposite as well as unfilled LDPE samples stressed with 50 Hz ac voltage has been studied. The tree inception voltage was monitored for various samples with different nano-filler loadings and it is seen that there is an increase in tree inception voltage with filler loading in LDPE. Treeing pattern and tree

Sridhar Alapati; M. Joy Thomas

2012-01-01

392

Decidability of Equivalence for Deterministic Synchronized Tree Automata  

Microsoft Academic Search

Synchronized tree automata allow limited communication between computations in independent subtrees of the input. This enables them to verify, for instance, the equality of two unary subtrees of unlimited size. The class of tree languages recognized by synchronized tree automata is strictly included in the context-free tree languages. As our main result we show that equivalence of tree languages recognized

Kai Salomaa

1995-01-01

393

Decidability of Equivalence for Deterministic Synchronized Tree Automata  

Microsoft Academic Search

Synchronized tree automata allow limited communication between computations in independent subtrees of the input. This enables them to verify, for instance, the equality of two unary subtrees of unlimited size. The class of tree languages recognized by synchronized tree automata is strictly included in the context-free tree languages. As our main result we show that equivalence of tree languages recognized

Kai Salomaa

1996-01-01

394

Online adaptive clustering in a decision tree framework  

Microsoft Academic Search

We present an online adaptive clustering algorithm in a decision tree framework which has an adaptive tree and a code formation layer. The code formation layer stores the representative codes of the clusters and the tree adapts the separating hyperplanes between the clusters. The membership of a sample in a cluster is decided by the tree and the tree parameters

Jayanta Basak

2008-01-01

395

Convex Relationships in Ecosystems Containing Mixtures of Trees and Grass  

Microsoft Academic Search

The relationship between grass production and the quantity of trees in mixed tree-grass ecosystems (savannas) is convex for all or most of its range. In other words, the grass production declines more steeply per unit increase in tree quantity at low tree cover than at high tree cover. Since much of the economic value in savannas is ultimately derived from

R. J. SCHOLES

396

A visualization tool for interactive learning of large decision trees  

Microsoft Academic Search

Decision tree induction is certainly among the most applicable learning techniques due to its power and simplicity. However learning decision trees from large datasets, particularly in data mining, is quite different from learning from small or moderately sized datasets. When learning from large datasets, decision tree induction programs often produce very large trees. How to efficiently visualize trees in the

Trong Dung Nguyen; Tu Bao Ho; Hiroshi Shimodaira

2000-01-01

397

ATreeGrep: Approximate Searching in Unordered Trees  

Microsoft Academic Search

An unordered labeled tree is a tree in which each node has a string label and the parent-child relationship is significant, but the order among siblings is unimportant. This paper presents an approach to the nearest neighbor search problem for these trees. Given a database of unordered labeled trees and a query tree , the goal is to find those

Dennis Shasha; Jason Tsong-li Wang; Huiyuan Shan; Kaizhong Zhang

2002-01-01

398

Slicing tree's geometric potential: an indicator for layout problems based on slicing tree structure  

Microsoft Academic Search

In this paper we propose an indicator to measure the capacity of a slicing tree to generate geometrically acceptable solutions for layout problems based on the slicing tree structure. This indicator can predict if, by making the appropriate cuts, the tree structure is able to generate layouts that satisfy the geometrical restrictions imposed on the items to be arranged. It

J. A. Diego-Mas; M. C. Santamarina-Siurana; V. A. Cloquell-Ballester; J. Alcaide-Marzal

2008-01-01

399

Lifetime growth patterns and ages of Bolivian rain forest trees obtained by tree ring analysis  

Microsoft Academic Search

Summary 1 Growth patterns and ages of tropical forest trees are strongly governed by temporal variation in light availability. Periods of high growth after canopy disturbances (releases) are necessary for successful canopy regeneration, but their importance cannot be studied without lifetime data. The recent detection of annual rings in tropical forest trees enables such analyses. 2 We used tree ring

ROEL J. W. BRIENEN; PIETER A. ZUIDEMA

2006-01-01

400

Multicast Routing in Wireless Mesh Networks: Minimum Cost Trees or Shortest Path Trees?  

Microsoft Academic Search

There exist two fundamental approaches to multicast routing: shortest path trees (SPTs) and minimum cost trees (MCTs). The SPT algorithms minimize the distance (or cost) from the sender to each receiver, whereas the MCT algorithms minimize the overall cost of the multicast tree. Due to the very large scale and unknown topology of the Internet, computing MCTs for multicast routing

Uyen Trang Nguyen; Jin Xu

2007-01-01

401

Tree Rings and the Aging of Trees: A Controversy in 19th Century America  

Microsoft Academic Search

During the late 19th Century there was considerable debate in the United States among members of the legal profession, the general public and even some scientists about the validity of using tree rings to determine tree age. In an earlier boundary dispute case in Maryland (1830) the Honorable Theodorick Bland rejected the use of tree rings to establish the date

Christopher H. Briand; Susan E. Brazer; Jeannine M. Harter-Dennis

2006-01-01

402

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.

403

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

Microsoft Academic Search

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

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

2006-01-01

404

The history of Newton's apple tree  

NASA Astrophysics Data System (ADS)

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

Keesing, R. G.

1998-05-01

405

Parallel analog neural networks for tree searching  

NASA Astrophysics Data System (ADS)

We have modeled parallel analog neural networks designed such that their evolution toward final states is equivalent to finding optimal (or nearly optimal) paths through decision trees. This work extends that done on the Traveling Salesman Problem (TSP)[1] and sheds light on the conditions under which analog neural networks can and cannot find solutions to discrete optimization problems. Neural networks show considerable specificity in finding optimal solutions for tree searches; in the cases when a final state does represent a syntactically correct path, that path will be the best path 70-90% of the time-even for trees with up to two thousand nodes. However, it appears that except for trivial networks lacking the ability to ``think globally,'' there exists no general network architecture that can strictly insure the convergence a state that represents a single, continuous, unambiguous path. In fact, we find that for roughly 15% of trees with six generations, 40% of trees with eight generations, and 70% of trees with ten generations, networks evolve to ``broken paths,'' i.e., combinations of the beginning of one and the end of another path through a tree. Tree searches illustrate well neural dynamics because tree structures make the effects of competition and positive feedback apparent. We have found that 1) convergence times for networks with up to 2000 neurons are very rapid, depend on the gain of neurons and magnitude of neural connections but not on the number of generations or branching factor of a tree, 2) all neurons along a ``winning'' path turn on exponentially with the same exponent, and 3) the general computational mechanism of these networks appears to be the pruning of a tree from the outer branches inward, as chain reactions of neurons being quenched tend to propagate along possible paths.

Saylor, Janet; Stork, David G.

1986-08-01

406

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

SciTech Connect

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

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

2009-07-31

407

New method for counting the number of spanning trees in a two-tree network  

NASA Astrophysics Data System (ADS)

The number of spanning trees is an important quantity characterizing the reliability of a network. Generally, the number of spanning trees in a network can be obtained by directly calculating a related determinant corresponding to the network. However, for a large network, evaluating the relevant determinant is intractable. In this paper, we investigate the number of spanning trees in two-tree networks. We first give a new algorithm which avoids the laborious computation of the determinant for counting the number of spanning trees. Using the algorithm, we can obtain the number of spanning trees of any two-tree network in linear time. The result shows that the computation complexity is O(n), which is better than that of the matrix tree theorem with O(n2), where n is the number of steps. We then characterize two-tree networks with the maximum and minimum numbers of spanning trees. Denote by P(t) and K(t), respectively, the two-tree networks of t+2 vertices with the maximum and minimum numbers of spanning trees. Denote by PA and EN, respectively, the two-tree network of t+2 vertices generated by preferential attachment and by equiprobability attachment. By algorithmic analysis and through simulations, we conjecture that N(K(t))?N(PA)?N(EN)?N(P(t)) as t tends to infinity, where N(G) is the number of spanning trees of G. As an application of the algorithm, we give the formula of the number of spanning trees of a particular small-world network.

Xiao, Yuzhi; Zhao, Haixing

2013-10-01

408

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

409

Using Decision Trees for Coreference Resolution  

Microsoft Academic Search

This paper describes RESOLVE, a s>stem that uses decision trees to learn how to classify coref- erent phrases in the domain of business joint ventures An experiment is presented in which the performance of RESOLVE is compared to the performance of a manually engineered set of rules for the same task The results show that decision trees achieve higher performance

Joseph F. Mccarthy; Wendy G. Lehnert

1995-01-01

410

Lazy Classifiers Using P-trees  

Microsoft Academic Search

Lazy classifiers store all of the training samples and do not build a classifier until a new sample needs to be classified. It differs from eager classifiers, such as decision tree induction, which build a general model (such as a decision tree) before receiving new samples. K-nearest neighbor (KNN) classification is a typical lazy classifier. Given a set of training

William Perrizo; Qin Ding; Anne Denton

2002-01-01

411

A Tree Grapher for the Linguist.  

National Technical Information Service (NTIS)

The paper describes a general purpose program used in the MIND system for graphically displaying finite trees. The program is based on a simple recursive algorithm which generates the display using a single deterministic walk of a tree which has been stor...

R. L. Bisbey

1971-01-01

412

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

413

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

414

Applications of Path Compression on Balanced Trees  

Microsoft Academic Search

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

Robert Endre Tarjan

1979-01-01

415

The Expected Additive Weight of Trees  

Microsoft Academic Search

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

Rainer Kemp

1989-01-01

416

Decision trees clarify novel technology applications  

Microsoft Academic Search

Decision trees provide a means for evaluating appropriate novel technologies for optimizing offshore platform topsides. This conclusion in a series of two articles continues to illustrate decision trees for selecting such equipment as: crude stabilizers; cyclone separators; emulsion treatment processes; hydrocyclones for primary oil\\/water separation; and powered centrifuges for primary oil\\/water\\/gas\\/sand separation.

J. J. MacDonald; R. S. Smith

1997-01-01

417

A new model for water tree propagation  

Microsoft Academic Search

A quantitative, physical model for water tree formation based on Zeller's concept is presented. The water tree is assumed to be composed of cavities filled with aqueous salts connected by narrow cylindrical conducting links. This structure is formed in the amorphous region of a polymer. The difference in conductivity between the links and cavities and the un-treed polymer, introduces an

J. Jow; L. A. Dissado

2000-01-01

418

Biological Networks: Comparison, Conservation, and Evolutionary Trees  

Microsoft Academic Search

Abstract. We describe a new approach for comparing cellular-biological networks, and finding conserved regions in two or more such networks. We use the length of describing one network, given the description of the other one, as a distance measure. We employ these distances as inputs for generating phylogenetic trees. Our algorithms are fast enough for generating phylogenetic tree of more

Benny Chor; Tamir Tuller

2006-01-01

419

Modeling mutually exclusive events in fault trees  

Microsoft Academic Search

A method is given for constructing fault tree gates to model mutually exclusive events. The gates are constructed from stochastically independent events, AND gates and NOT gates. Examples are presented to illustrate the technique. If the gate construction must be performed manually, the method adds complexity to the fault tree model that may not be justified. Approximating mutually exclusive events

D. W. Twigg; A. V. Ramesh; U. R. Sandadi; T. C. Sharma

2000-01-01

420

Fault tree analysis for maintenance needs  

Microsoft Academic Search

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

Jari Halme; Antti Aikala

2012-01-01

421

BuildingaTree-BankofModern Hebrew Text  

Microsoft Academic Search

This paper describes the process of building the first tree-bank for Modern Hebrew texts. A major concern in this process is the need for reducing the cost of manual annotation by the use of automatic means. To this end, the joint utility of an automatic morphological ana- lyzer, a probabilistic parser and a small manually annotated tree-bank was explored. An

Khalil Sima; Alon Itai; Yoad Winter

422

Percolation on general trees and HIV modeling  

NASA Astrophysics Data System (ADS)

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

Ahmed, E.; Agiza, H. N.

1996-12-01

423

Decision tree methods in pharmaceutical research.  

PubMed

Decision trees are among the most popular of the new statistical learning methods being used in the pharmaceutical industry for predicting quantitative structure-activity relationships. This article reviews applications of decision trees in drug discovery research and extensions to the basic algorithm using hybrid or ensemble methods that improve prediction accuracy. PMID:16454756

Blower, Paul E; Cross, Kevin P

2006-01-01

424

Regulation of floral initiation in horticultural trees  

Microsoft Academic Search

The intention of this review is to discuss floral initiation of horticultural trees. Floral initiation is best understood for herbaceous species, especially at the molecular level, so a brief overview of the control of floral initiation of Arabidopsis (Arabidopsis thaliana (L.) Heynh.) precedes the discussion of trees. Four major pathways to flowering have been characterized in Arabidopsis, including environmental induction

John D. Wilkie; Margaret Sedgley; Trevor Olesen

2008-01-01

425

Learning decision trees using the Fourier spectrum  

Microsoft Academic Search

This work gives a polynomial time algorithm for learning decision trees with respectto the uniform distribution. (This algorithm uses membership queries.) The decision treemodel that is considered is an extension of the traditional boolean decision tree model thatallows linear operations in each node (i.e., summation of a subset of the input variablesover GF (2)).This paper shows how to learn in

Eyal Kushilevitz; Yishay Mansourt

1991-01-01

426

Converting Discrete Images to Partitioning Trees  

Microsoft Academic Search

The discrete space representation of most scientific datasets (pixels, voxels, etc.), generated through instruments or by sampling continuously defined fields, while being simple, is also verbose and structureless. We propose the use of a particular spatial structure, the binary space partitioning tree, or, simply, partitioning tree, as a new representation to perform efficient geometric computation in discretely defined domains. The

Kalpathi R. Subramanian; Bruce F. Naylor

1997-01-01

427

Learning Decision Trees over Erasing Pattern Languages  

NASA Astrophysics Data System (ADS)

In this paper, we consider a learning problem of decision trees over erasing patterns from positive examples in the framework of identification in the limit due to Gold and Angluin. An erasing pattern is a string pattern with constant symbols and erasable variables. A decision tree over erasing patterns can be applied to identify or express transmembrane domains of amino acid sequences, and gives intuitive knowledge expressions. We first show that the ordinary decision trees with height 1 over erasing regular patterns are learnable but those with height at most 2 are not learnable from positive examples. Then we introduce a co-pattern pc for an erasing pattern p, and we redefine the language of a decision tree over erasing patterns as a language obtainable by finitely many applications of union operations and intersection operations to the languages of erasing patterns and co-patterns. Under the new definition of decision trees, we show that these decision trees with height at most n are learnable from positive examples. Moreover, we investigate efficient learning algorithms for decision trees with height 1. Terada et al. discussed the same problem for decision trees over nonerasing patterns, and the results obtained in the present work are natural extensions of Terada's results.

Mukouchi, Yasuhito; Sato, Masako

2008-07-01

428

Deciding Monadic Theories of Hyperalgebraic Trees  

Microsoft Academic Search

We show that the monadic second-order theory of any infinite tree generated by a higher-order grammar of level 2 subject to a certain syntactic restriction is decidable. By this we extend the result of Courcelle [7] that the MSO theory of a tree generated by a grammar of level 1 (algebraic) is decidable. To this end, we develop a technique

Teodor Knapik; Damian Niwinski; Pawel Urzyczyn

2001-01-01

429

The tree equivalence of linear recursion schemes  

Microsoft Academic Search

Abstract: In the paper, a complete system of transformation rules preserving thetree equivalence and a polynomial-time algorithm deciding the tree equivalenceof linear polyadic recursion schemes are proposed. The algorithm isformulated as a sequential transformation process which brings togetherthe schemes in question. In the last step, the tree equivalence problemfor the given schemes is reduced to a global flow analysis problem

Viktor K. Sabelfeld

2000-01-01

430

Paths, Trees and Cycles in Tournaments  

Microsoft Academic Search

We survey results on paths, trees and cycles in tournaments. The main subjects are hamiltonian paths and cycles, vertex and arc disjoint paths with prescribed endvertices, arc-pancyclicity, oriented paths, trees and cycles in tour- naments. Several unsolved problems are included.

Jørgen Bang-Jensen; Gregory Gutin

431

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

432

Smart Spanning Tree Bridging for Carrier Ethernets  

Microsoft Academic Search

Carrier Ethernet WAN transport services are taking off rapidly and the simplicity, ubiquity, and plug-and-play features of Ethernet are some key success factors. Originally, these transport services assumed the use of VLANs and spanning tree protocols within provider bridge (PB) and provider backbone bridge (PBB) networks. Because the existing spanning tree protocols (STP, RSTP, and MSTP) were deemed inadequate for

Aref Meddeb

2008-01-01

433

Nearest Neighbor Search using Kd-trees  

Microsoft Academic Search

We suggest a simple modification to the kd-tree search algorithm for nearest neighbor search re- sulting in an improved performance. The Kd-tree data structure seems to work well in finding nearest neighbors in low dimensions but its performance degrades even if the number of dimensions increases to more than three. Since the exact nearest neighbor search problem suffers from the

Rina Panigrahy

434

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

435

Integral trees with diameters 5 and 6  

Microsoft Academic Search

In this paper, some new families of integral trees with diameters 5 and 6 are constructed. All these classes are infinite. These are different from those in the existing literature. We also prove that the problem of finding integral trees of diameters 5 and 6 is equivalent to the problem of solving some Diophantine equations. The discovery of these integral

Ligong Wang; Xueliang Li

2005-01-01

436

Maintaining Spanning Trees of Small Diameter  

Microsoft Academic Search

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

Giuseppe F. Italiano; Rajiv Ramaswami

1998-01-01

437

Maintaining Spanning Trees of Small Diameter  

Microsoft Academic Search

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

Giuseppe F. Italiano; Rajiv Ramaswami

1994-01-01

438

On the Area of Binary Tree Layouts  

Microsoft Academic Search

Abstract The binary tree is an important interconnection pattern for VLSI chip layouts. Suppose that the nodes are separated by at least unit distance and that a wire has unit width. The usual layout of a complete binary tree with n leaves takes chip area,( nlogn), but it can be arranged that all the leaves are on the boundary of

Richard P. Brent; H. T. Kung

1980-01-01

439

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

440

DISPLACEMENT ECOLOGY OF TREES NEAR UPPER TIMBERLINE  

Microsoft Academic Search

Tree invasions into meadows near upper timberline reduce diversity of habitat and diminish high-elevation food sources for black (Ursus americanus) and grizzly (Ursus arctos) bears. How serious is this threat in view of future climate change? Tree invasions observed in the Pacific Northwest to New Mexico suggest that climatic restraints to forest expansion have relaxed since the end of the

WILLIAM H. MOIR; LAURIE S. HUCKABY

441

How Trees Help the Power Company!  

ERIC Educational Resources Information Center

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

King, Rik

1992-01-01

442

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

443

From Game Trees to Game Graphs.  

National Technical Information Service (NTIS)

The definition of the score of a game tree is extended using the minimax rule to game graphs containing cycles. This is accomplished by taking the limit of a sequence of scores of game trees that in some sense approximate the game graph. It is shown that ...

W. T. M. Kars

1990-01-01

444

Split Selection Methods for Classification Trees  

Microsoft Academic Search

Classification trees based on exhaustive search algorithms tend to be biased towards selectingvariables that afford more splits. As a result, such trees should be interpreted with caution.This article presents an algorithm called QUEST that has negligible bias. Its split selectionstrategy shares similarities with the FACT method, but it yields binary splits and the final treecan be selected by a direct

Wei-yin Loh; Yu-shan Shih

1997-01-01

445

Dynamic Fault Tolerance in Fat Trees  

Microsoft Academic Search

Fat trees are a very common communication architecture in current large-scale parallel computers. The probability of failure in these systems increases with the number of components. We present a routing method for deterministically and adaptively routed fat trees, applicable to both distributed and source routing, that is able to handle several concurrent faults and that transparently returns to the original

Frank Olaf Sem-Jacobsen; Tor Skeie; Olav Lysne; José Duato

2011-01-01

446

The use of classification trees for bioinformatics  

PubMed Central

Classification trees are non-parametric statistical learning methods that incorporate feature selection and interactions, possess intuitive interpretability, are efficient, and have high prediction accuracy when used in ensembles. This paper provides a brief introduction to the classification tree-based methods, a review of the recent developments, and a survey of the applications in bioinformatics and statistical genetics.

Chen, Xiang; Wang, Minghui; Zhang, Heping

2011-01-01

447

Spatiotemporal Relational Probability Trees: An Introduction  

Microsoft Academic Search

We introduce spatiotemporal relational probability trees (SRPTs), probability estimation trees for relational data that can vary in both space and time. The SRPT algo- rithm addresses the exponential increase in search complex- ity through sampling. We validate the SRPT using a sim- ulated data set and we empirically demonstrate the SRPT algorithm on two real-world data sets.

Amy Mcgovern; Nathan C. Hiers; Matthew W. Collier; David J. Gagne II; Rodger A. Brown

2008-01-01

448

The Tree Man: Robert Mazibuko's Story.  

ERIC Educational Resources Information Center

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

Bloch, Joanne, Ed.

449

Robust model for finding optimal evolutionary trees.  

National Technical Information Service (NTIS)

Constructing evolutionary trees for species sets is a fundamental problem in biology. One of the standard models assumes the ability to compute distances between every pair of species and seeks to find an edge-weighted tree T in which the distance d(sub i...

M. Farach S. Kannan T. Warnow

1993-01-01

450

Construction and annotation of large phylogenetic trees  

Microsoft Academic Search

Broad availability of molecular sequence data allows construction of phylogenetic trees with 1000s or even 10 000s of taxa. This paper reviews methodological, technological and empirical issues raised in phylogenetic inference at this scale. Numerous algorithmic and computational challenges have been identified surrounding the core problem of reconstructing large trees accurately from sequence data, but many other obstacles, both upstream

Michael J. Sanderson

451

The Tree Man: Robert Mazibuko's Story.  

ERIC Educational Resources Information Center

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

Bloch, Joanne, Ed.

452

Efficient algorithms for generalized cut trees  

Microsoft Academic Search

The Gomory-Hu cut tree is a compact and efficiently computed representation of selected minimum edge cuts in a weighted undirected graph G=(V,E) with n nodes. It represents (y) minimum cuts, one for each pair of nodes in G, and can be constructed with only n - 1 flow computations. In this paper we generalize the types of cut trees that

Dan Gusfield; Dalit Naor

1990-01-01

453

The Sacred Tree in Ancient Greek Religion  

Microsoft Academic Search

The purpose of this study is to examine the role played by the tree cult in the religion of the ancient Greeks, and to discuss various aspects and instances of tree worship which survived into the Classical period and later. By this means it is to some extent possible to deduce information regarding the form and character of the religion

Karolyn Elizabeth Smardz

1979-01-01

454

Mosses on a tree in forest habitat  

NSDL National Science Digital Library

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

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

2007-01-13

455

Model Selection for Mixtures of Mutagenetic Trees  

Microsoft Academic Search

The evolution of drug resistance in HIV is characterized by the accumulation of resistance-associated mutations in the HIV genome. Mutagenetic trees, a family of restricted Bayesian tree models, have been applied to infer the order and rate of occurrence of these mutations. Understanding and predicting this evolutionary process is an important prerequisite for the rational design of antiretroviral therapies. In

Junming Yin; Niko Beerenwinkel; Thomas Lengauer

2006-01-01

456

Effects of pressures inside Monterey pine trees  

Microsoft Academic Search

The diurnal change in diameter of trees, aside from effects due to temperature, must be due to changes of pressure inside the tree. Monterey pines (Pinus radiata), as well as other pines, have two liquid systems, the sap system and the resin system. The sap is under a negative pressure, while the resin is under a positive pressure. Each system

H. Victor Neher

1993-01-01

457

Stiffness gradients in radiata pine trees  

Microsoft Academic Search

A mill study of 62 trees, in which boards were reassembled into their original logs, permitted the construction of wood quality maps. In this instance stiffness profiles were obtained from butt to upper-top logs, based on machine stress grading of all boards and then averaging values from the 62 trees. Traditionally the butt log has been perceived to be the

Ping Xu; J. C. F. Walker

2004-01-01

458

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...

459

Regular trees in random regular graphs  

Microsoft Academic Search

We investigate the size of the embedded regular tree rooted at a vertex in a $d$ regular random graph. We show that almost always, the radius of this tree will be ${1\\/2}\\\\log n$, where $n$ is the number of vertices in the graph. And we give an asymptotic estimate for Gauss' Hypergeometric Function.

Eran Makover; Jeffrey McGowan

2006-01-01

460

Unordered Tree Mining with Applications to Phylogeny  

Microsoft Academic Search

Frequent structure mining (FSM) aims to discover and extract patterns frequently occurring in structural data, such as trees and graphs. FSM finds many applications in bioinformatics, XML processing, Web log analysis, and so on. In this paper we present a new FSM technique for find- ing patterns in rooted unordered labeled trees. The patterns of interest are cousin pairs in

Dennis Shasha; Jason Tsong-li Wang; Sen Zhang

2004-01-01

461

16 CFR 501.2 - Christmas tree ornaments.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

462

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

463

Prioritizing preferable locations for increasing urban tree canopy in ...  

Treesearch

Forest Products Lab ... may contribute to increasing urban tree canopy (UTC) while also achieving their own programmatic goals. ... urban tree canopy, possible, preferable, geographic information systems, GIS, trees, green space, vegetation.

464

New Method for Abbreviating the Fault Tree Graphical Representation.  

National Technical Information Service (NTIS)

Fault tree analysis is being widely used for reliability and safety analysis of systems encountered in the nuclear industry and elsewhere. A disadvantage of the fault tree method is the voluminous fault tree graphical representation that conventionally re...

M. E. Stewart J. B. Fussell R. J. Crump

1974-01-01

465

29 CFR 780.208 - Forest and Christmas tree activities.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

466

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

467

Interception of airborne particles by tree plantings  

SciTech Connect

The ability of tree plantings to abate overland movement of particulate pollutants was examined. Estimates of deposition of dust and of total suspended particles indicated that, in comparison to clearcut sites, tree plantings in both urban and rural locations were effective in reducing the amount of particulate matter in the atmosphere. During an 8-month sampling period, the overall reduction of dustfall by deciduous trees was 30% (rural) and 27% (urban). In comparison, rural and urban coniferous stands reduced dustfall by 42 and 38%, respectively. Interception of total suspended particles was 11% for deciduous trees and 13% for conifers at the rural site, and 9% for deciduous trees and 13% for conifers at the urban site.

Dochinger, L.S.

1980-04-01

468

Practical application of fault tree analysis  

SciTech Connect

A detailed survey of standard and novel approaches to Fault Tree construction, based on recent developments at Du Pont, covers the effect-to-cause procedure for control systems as in process plants; the effect-to-cause procedure for processes; source-of-hazard analysis, as in pressure vessel rupture; use of the ''fire triangle'' in a Fault Tree; critical combinations of safeguard failures; action points for automatic or operator control of a process; situations involving hazardous reactant ratios; failure-initiating and failure-enabling events and intervention by the operator; ''daisy-chain'' hazards, e.g., in batch processes and ship accidents; combining batch and continuous operations in a Fault Tree; possible future structure-development procedures for fault-tree construction; and the use of quantitative results (calculated frequencies of Top-Event occurrence) to restructure the Fault Tree after improving the process to any acceptable risk level.

Prugh, R.W.

1980-01-01

469

MTVis: tree exploration using a multitouch interface  

NASA Astrophysics Data System (ADS)

We present MTVis, a multi-touch interactive tree visualization system. The multi-touch interface display hardware is built using the LED-LP technology, and the tree layout is based on RINGS, but enhanced with multitouch interactions. We describe the features of the system, and how the multi-touch interface enhances the user's experience in exploring the tree data structure. In particular, the multi-touch interface allows the user to simultaneously control two child nodes of the root, and rotate them so that some nodes are magnified, while preserving the layout of the tree. We also describe the other meaninful touch screen gestures the users can use to intuitively explore the tree.

Andrews, David; Teoh, Soon Tee

2010-01-01

470

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

471

Computer architecture using self-manipulating trees  

US Patent & Trademark Office Database

A computer architecture operates a computer using self-manipulating trees. A source is input and is matched to a self-manipulating tree using open-ended inviting to match identities to portions of the source. After activating the root node of the self-manipulating tree, the self-manipulating tree self-manipulates according to the instructions for self-manipulating contained in the identities pointed to by the nodes of the self-manipulating tree. The invention may be used as a natural language search engine for electronic data bases, a natural language programming language, a parser-free computer operating system, a computer problem solving system, and as an enhancement feature for general purpose computers and general purpose computer applications, such as a translator and a help engine.

Spooner; Christopher (Washington, DC); Spooner; Richard (Washington, DC)

2001-07-03

472

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.

McInerney, James; Cummins, Carla; Haggerty, Leanne

2011-01-01

473

TreeViewJ: An application for viewing and analyzing phylogenetic trees  

PubMed Central

Background Phylogenetic trees are widely used to visualize evolutionary relationships between different organisms or samples of the same organism. There exists a variety of both free and commercial tree visualization software available, but limitations in these programs often require researchers to use multiple programs for analysis, annotation, and the production of publication-ready images. Results We present TreeViewJ, a Java tool for visualizing, editing and analyzing phylogenetic trees. The software allows researchers to color and change the width of branches that they wish to highlight, and add names to nodes. If collection dates are available for taxa, the software can map them onto a timeline, and sort the tree in ascending or descending date order. Conclusion TreeViewJ is a tool for researchers to visualize, edit, "decorate," and produce publication-ready images of phylogenetic trees. It is open-source, and released under an GPL license, and available at .

Peterson, Matthew W; Colosimo, Marc E

2007-01-01

474

Decision Tree for Optimization Software  

NSDL National Science Digital Library

H.D. Mittelmann from the Department of Math and Statistics at Arizona State University and P. Spellucci from Department of Mathematics at Technical University Darmstadt have posted this guide entitled, Decision Tree for Optimization Software. The guide "aims at helping you identify ready to use solutions for your optimization problem, or at least to find some way to build such a solution using work done by others." The online document is organized into sections covering specific software problems, a collection of test results and performance tests, and example files to use with existing software. The authors also list information on available books and tutorials, some of which are online, as well as various software tools to assist in formulating an optimization problem or simplifying its solution. Those tools listed in the Web-submission section are available to try directly via the Internet.

475

How early ferns became trees.  

PubMed Central

A new anatomically preserved fern, discovered from the basalmost Carboniferous of Australia, shows a unique combination of very primitive anatomical characters (solid centrarch cauline protostele) with the elaboration of an original model of the arborescent habit. This plant possessed a false trunk composed of a repetitive branching system of very small stems, which established it as the oldest tree-fern known to date. The potential of this primitive zygopterid fern to produce such an unusual growth form-without real equivalent among living plants-is related to the possession of two kinds of roots that have complementary functional roles: (i) large roots produced by stems with immediate positive geotropism, strongly adapted to mechanical support and water uptake from the soil; and (ii) small roots borne either on large roots or on petiole bases for absorbing humidity inside the false trunk.

Galtier, J; Hueber, F M

2001-01-01

476

How early ferns became trees.  

PubMed

A new anatomically preserved fern, discovered from the basalmost Carboniferous of Australia, shows a unique combination of very primitive anatomical characters (solid centrarch cauline protostele) with the elaboration of an original model of the arborescent habit. This plant possessed a false trunk composed of a repetitive branching system of very small stems, which established it as the oldest tree-fern known to date. The potential of this primitive zygopterid fern to produce such an unusual growth form-without real equivalent among living plants-is related to the possession of two kinds of roots that have complementary functional roles: (i) large roots produced by stems with immediate positive geotropism, strongly adapted to mechanical support and water uptake from the soil; and (ii) small roots borne either on large roots or on petiole bases for absorbing humidity inside the false trunk. PMID:11564354

Galtier, J; Hueber, F M

2001-09-22

477

Electrical signals in avocado trees  

PubMed Central

Plant responses to environmental changes are associated with electrical excitability and signaling; automatic and continuous measurements of electrical potential differences (?EP) between plant tissues can be effectively used to study information transport mechanisms and physiological responses that result from external stimuli on plants. The generation and conduction of electrochemical impulses within plant different tissues and organs, resulting from abiotic and biotic changes in environmental conditions is reported. In this work, electrical potential differences are monitored continuously using Ag/AgCl microelectrodes, inserted 5 mm deep into sapwood at two positions in the trunks of several Avocado trees. Electrodes are referenced to a non polarisable Ag/AgCl microelectrode installed 20 cm deep in the soil. Systematic patterns of ?EP during absolute darkness, day-night cycles and different conditions of soil water availability are discussed as alternative tools to assess early plant stress conditions.

Oyarce, Patricio

2010-01-01

478

Tectonic discrimination of basalts with classification trees  

NASA Astrophysics Data System (ADS)

Traditionally, geochemical classification of basaltic rocks of unknown tectonic affinity has been performed by discrimination diagrams. Although easy to use, this method is fairly inaccurate because it only uses bi- or trivariate data. Furthermore, many popular discrimination diagrams are statistically not very rigorous because the decision boundaries are drawn by eye, and they ignore closure, thus violating the rules of compositional data analysis. Classification trees approximate the data space by a stepwise constant function, and are a more rigorous and potentially more effective way to determine tectonic affinity. Trees allow the simultaneous use of an unlimited number of geochemical features, while still permitting visualization by an easy-to-use, two-dimensional graph. Two classification trees are presented for the discrimination of basalts of mid-ocean ridge, ocean island, and island arc affinities. The first tree uses 51 major, minor, and trace elements and isotopic ratios and should be used for the classification of fresh basalt samples. A second tree only uses high field strength element analyses and isotopic ratios, and can also be used for basalts that have undergone alteration. The probability of successful classification is 89% for the first and 84% for the second tree, as determined by 10-fold cross-validation. Even though the trees presented in this paper use many geochemical features, it is not a problem if some of these are missing in the unknown sample. Classification trees solve this problem with surrogate variables, which give more or less the same decision as the primary variables. The advantages of the classification tree approach over discrimination diagrams are illustrated by a comparative test on a sample dataset of known tectonic affinities. Although arguably better than discrimination diagrams, classification trees are not perfect, and the limitations of the method are illustrated on a published dataset of basalts from the Pindos Basin (Greece).

Vermeesch, Pieter

2006-04-01

479

Amalgamating source trees with different taxonomic levels.  

PubMed

Supertree methods combine a collection of source trees into a single parent tree or supertree. For almost all such methods, the terminal taxa across the source trees have to be non-nested for the output supertree to make sense. Motivated by Page, the first supertree method for combining rooted source trees where the taxa can be hierarchically nested is called AncestralBuild. In addition to taxa labeling the leaves, this method allows the rooted source trees to have taxa labeling some of the interior nodes at a higher taxonomic level than their descendants (e.g., genera vs. species). However, the utility of AncestralBuild is somewhat restricted as it is mostly intended to decide if a collection of rooted source trees is compatible. If the initial collection is not compatible, then no tree is returned. To overcome this restriction, we introduce here the MultiLevelSupertree (MLS) supertree method whose input is the same as that for AncestralBuild, but which accommodates incompatibilities among rooted source trees using a MinCut-like procedure. We show that MLS has several desirable properties including the preservation of common subtrees among the source trees, the preservation of ancestral relationships whenever they are compatible, as well as running in polynomial time. Furthermore, application to a small test data set (the mammalian carnivore family Phocidae) indicates that the method correctly places nested taxa at different taxonomic levels (reflecting vertical signal), even in cases where the input trees harbor a significant level of conflict between their clades (i.e., in their horizontal signal). PMID:23179602

Berry, Vincent; Bininda-Emonds, Olaf R P; Semple, Charles

2012-11-23

480

An efficient and extensible approach for compressing phylogenetic trees  

PubMed Central

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

2011-01-01

481

The LSDh-Tree: An Access Structure for Feature Vectors  

Microsoft Academic Search

Efficient access structures for similarity queries on feature vectors are an important research topic for application areas such as multimedia databases, molecular biology or time series analysis. Different access structures for high dimensional feature vectors have been proposed, namely: the SS-tree, the VAMSplit R-tree, the TV-tree, the SR-tree and the X-tree. All these access structures are derived from the R-tree.

Andreas Henrich

1998-01-01

482

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

483

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.

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

2012-01-01

484

Photosynthesis, Trees, and the Greenhouse Effect  

NSDL National Science Digital Library

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

485

Tree Rings as Records of the Past  

NSDL National Science Digital Library

In this activity students will examine sections of cut trees. They will observe and describe the difference between early and late wood, make a guess about the age of the tree, determine the actual age by counting the rings, and identify the rings that represent the years the student, the student's parents, and the student's grandparents were born, or years of historical importance. In addition, students may identify the narrowest rings, then check precipitation records to see if these coincide with years of low rainfall. They will discover that trees grow in diameter by producing new wood in the layer just beneath their bark.

Bjornerud, Marcia

486

Random tree growth by vertex splitting  

NASA Astrophysics Data System (ADS)

We study a model of growing planar tree graphs where in each time step we separate the tree into two components by splitting a vertex and then connect the two pieces by inserting a new link between the daughter vertices. This model generalizes the preferential attachment model and Ford's ?-model for phylogenetic trees. We develop a mean field theory for the vertex degree distribution, prove that the mean field theory is exact in some special cases and check that it agrees with numerical simulations in general. We calculate various correlation functions and show that the intrinsic Hausdorff dimension can vary from 1 to ?, depending on the parameters of the model.

David, F.; Dukes, W. M. B.; Jonsson, T.; Stefánsson, S. Ö.

2009-04-01

487

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

NSDL National Science Digital Library

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

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

2002-01-01

488

Theory of Protein Evolutionary Trees  

NASA Astrophysics Data System (ADS)

A continuum copolymer model of proteins is introduced in which complete correspondence between sequence and structure can be established. The 11440 sequences of the model split into 15 classes, each corresponding to a different folded configuration. In each class the folding times ?F and folding temperatures TF of different sequences are nearly the same, but different classes have different levels of foldability. Thus, sequence disorder can be classified into two types - one that changes frustration with respect to the native state, and one that does not. Two minimally frustrated sequence classes ? and ? are found having the most optimal TF and ?_F. Evolution in sequence space can then be described in terms of an order parameter Q_seq, where Q_seq(?) = 0 and Q_seq(?) = 1, and a barrier of maximum frustration is found at Q_seq ~ .5 where the sequence ordering tendencies of ? and ? are completely mixed. We propose an evolutionary temperature TE to describe the optimization threshold that proteins must exceed to be considered foldable in nature. If this temperature exceeds a critical value TC connected with the size of the frustration barrier, a bifurcation occurs in which every mutational path connecting ? to ? must visit a non folding region of sequence space. We propose that such events describe the classification of proteins into evolutionary trees.

Nelson, Erik; Onuchic, Jose

1998-03-01

489

Distributed game-tree searching  

SciTech Connect

Conventional parallelizations of the alpha-beta ({alpha}{beta}) algorithm have met with limited success. Implementations suffer primarily from the synchronization and search overheads of parallelization. This paper describes a parallel {alpha}{beta} searching program that achieves high performance through the use of four different types of processes: Controllers, Searchers, Table Managers, and Scouts. Synchronization is reduced by having Controller process reassigning idle processes to help out busy ones. Search overhead is reduced by having two types of parallel table management: global Table Managers and the periodic merging and redistribution of local tables. Experiments show that nine processors can achieve 5.67-fold speedups but beyond that, additional processors provide diminishing returns. Given that additional resources are of little benefit, speculative computing is introduced as a means of extending the effective number of processors that can be utilized. Scout processes speculatively search ahead in the tree looking for interesting features and communicate this information back to the {alpha}{beta} program. In this way, the effective search depth is extended. These ideas have been tested experimentally and empirically as part of the chess program ParaPhoenix.

Schaeffer, J. (Computing Science Dept., Univ. of Alberta, Alberta (CA))

1989-02-01

490

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

491

Full modeling versus summarizing gene-tree uncertainty: method choice and species-tree accuracy.  

PubMed

With the proliferation of species-tree methods, empiricists now have to confront the daunting task of method choice. Such decisions might be made based on theoretical considerations alone. However, the messiness of real data means that theoretical ideals may not hold in practice (e.g., with convergence of complicated MCMC algorithms and computational times that limit analyses to small data sets). On the other hand, simplifying assumptions made by some approaches may compromise the accuracy of species-tree estimates. Here we examine the purported tradeoff between accuracy and computational simplicity for species-tree analysis, focusing on the different ways the approaches treat gene-tree uncertainty. By considering a diversity of species trees, as well as different sampling designs and total sampling efforts, we not only compare the accuracy of species-tree estimates across methods, but we also partition the variation in accuracy across factors to identify their relative importance. This analysis shows that although the method of analysis affects accuracy, other factors - namely, the history of species divergence and aspects of the sampling design - have a larger impact. Despite a full modeling of gene tree uncertainty (e.g., using a Bayesian framework), species-tree estimates may not be accurate, particularly for recent diversification histories. Nevertheless, we demonstrate how factors within the control of the empirical investigator (e.g., decisions about sampling) improve the accuracy of species tree estimates, and more so than the method of analysis. Lastly, with much of the attention on species-tree analyses focused on the discord among loci arising from the coalescent, this work also highlights a previously overlooked key determinant of species-tree accuracy for recent divergences - the level of genetic variation at a locus, which has important implications for improving species-tree estimates in practice. PMID:22835380

Knowles, L Lacey; Lanier, Hayley C; Klimov, Pavel B; He, Qixin

2012-07-23

492

Tree-pulling experiment: an analysis into the mechanical stability of rain trees  

Microsoft Academic Search

Tree-pulling experiments were conducted in Singapore involving 20 rain trees (Samanea saman) growing in four different soil types (1) structural soil with 80% granite chips and 20% sandy loam soil, (2) structural\\u000a soil with 50% granite chips and 50% sandy loam soil, (3) in situ soil and (4) top soil. The trees were pulled over with a\\u000a winch attached to

Lai Fern Ow; F. R. Harnas; I. G. B. Indrawan; A. Sahadewa; E. K. Sim; H. Rahardjo; E. C. Leong; Y. K. Fong; P. Y. Tan

2010-01-01

493

Private Trees as Household Assets and Determinants of Tree-Growing Behavior in Rural Ethiopia  

Microsoft Academic Search

This study looked into tree-growing behavior of rural households in Ethiopia. With data collected at household and parcel levels from the four major regions of Ethiopia, we analyzed the decision to grow trees and the number of trees grown, using such econometric strategies as a zero-inflated negative binomial model, Heckman’s two-step procedure, and panel data techniques. Our findings show the

Alemu Mekonnen; Abebe Damte

2011-01-01

494

Production rates and costs of whole-tree, tree length, and log-length skyline thinning  

Microsoft Academic Search

Production rates and costs were determined for harvesting smallwood by different methods of skyline yarding: whole-tree (yarding with limbs and tops), tree-length (bucking done on the landing), and log-length (limbing, topping, and bucking done on the slope). A rubber-tired skidder was used to swing and sort the variously cut trees from the landing to a site on the haul road

N. E. Putman; L. D. Kellogg; E. D. Olsen

1984-01-01

495

Box-trees and R-trees with near-optimal query time  

Microsoft Academic Search

A box-tree is a \\\\ifasci so-called \\\\emph{bounding-volume hierarchy} \\\\else bounding-volume hierarchy \\\\fi that uses axis-aligned boxes as bounding volumes. The query complexity of a box-tree with respect to a given type of query is the maximum number of nodes visited when answering such a query. We describe several new algorithms for constructing box-trees with small worst-case query complexity with respect

Pankaj K. Agarwal; Mark de Berg; Joachim Gudmundsson; Mikael Hammar; Herman J. Haverkort

2001-01-01

496

Taming Trees: Capital, Science, and Nature in Pacific Slope Tree Improvement  

Microsoft Academic Search

This article traces the emergence of industrial tree improvement along the Pacific Slope of western Oregon and Washington. Anxieties about timber famine in the United States prompted research on forest genetics and Douglas-fir provenance as far back as 1913, while diminishing supplies of old-growth timber resources in this region led to tree improvement—systematic tree breeding to enhance commercially attractive characteristics—on

Scott Prudham

2003-01-01

497

Technique and interpretation in tree seed radiography  

Treesearch

Title: Technique and interpretation in tree seed radiography ... suggest how radiographs can contribute to an understanding of the biology of seed formation. ... Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows ...

498

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

499

Tree Planters' Notes, Volume 49, No. 3.  

National Technical Information Service (NTIS)

Contents: Improving Forest Regeneration Through Nursery Accreditation; Micronutrients: Copper; Low-Budget Pollen Collector; Removing Douglas-fir Cones With a Lower-Crown Branch Shaker; Production and Quality Requirements of Forest Tree Seedlings in Finlan...

G. A. Hernandez K. E. Burr

2000-01-01

500

Electrochemical Treeing in Cable. Final Report.  

National Technical Information Service (NTIS)

Results are presented of an investigation of electrochemical treeing in solid dielectric insulated cables performed between May, 1973 and March, 1977 for the Electric Power Research Institute. The purpose of the work was to establish the influence of vari...

N. Nagu inivas H. C. Deopken A. L. McKean M. C. Biskeborn

1978-01-01