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1

The draft genome of the transgenic tropical fruit tree papaya (Carica papaya Linnaeus)  

Microsoft Academic Search

Papaya, a fruit crop cultivated in tropical and subtropical regions, is known for its nutritional benefits and medicinal applications. Here we report a 3× draft genome sequence of `SunUp' papaya, the first commercial virus-resistant transgenic fruit tree to be sequenced. The papaya genome is three times the size of the Arabidopsis genome, but contains fewer genes, including significantly fewer disease-resistance

Ray Ming; Shaobin Hou; Yun Feng; Qingyi Yu; Alexandre Dionne-Laporte; Jimmy H. Saw; Pavel Senin; Wei Wang; Benjamin V. Ly; Kanako L. T. Lewis; Lu Feng; Meghan R. Jones; Rachel L. Skelton; Jan E. Murray; Cuixia Chen; Wubin Qian; Junguo Shen; Peng Du; Moriah Eustice; Eric Tong; Haibao Tang; Eric Lyons; Robert E. Paull; Todd P. Michael; Kerr Wall; Danny W. Rice; Henrik Albert; Ming-Li Wang; Yun J. Zhu; Michael Schatz; Niranjan Nagarajan; Ricelle A. Acob; Peizhu Guan; Andrea Blas; Ching Man Wai; Christine M. Ackerman; Yan Ren; Chao Liu; Jianmei Wang; Jianping Wang; Jong-Kuk Na; Eugene V. Shakirov; Brian Haas; Jyothi Thimmapuram; David Nelson; Xiyin Wang; John E. Bowers; Andrea R. Gschwend; Arthur L. Delcher; Ratnesh Singh; Jon Y. Suzuki; Savarni Tripathi; Kabi Neupane; Hairong Wei; Beth Irikura; Maya Paidi; Ning Jiang; Wenli Zhang; Gernot Presting; Aaron Windsor; Rafael Navajas-Pérez; Manuel J. Torres; F. Alex Feltus; Brad Porter; Yingjun Li; A. Max Burroughs; Ming-Cheng Luo; Lei Liu; David A. Christopher; Stephen M. Mount; Paul H. Moore; Tak Sugimura; Jiming Jiang; Mary A. Schuler; Vikki Friedman; Thomas Mitchell-Olds; Dorothy E. Shippen; Claude W. Depamphilis; Jeffrey D. Palmer; Michael Freeling; Andrew H. Paterson; Dennis Gonsalves; Lei Wang; Maqsudul Alam

2008-01-01

2

Evaluation of volatiles from ripening papaya ( Carica papaya L., var. Maradol roja)  

Microsoft Academic Search

The effect of ripening on the chemical composition of papaya (Carica papaya L., var. Maradol roja), especially regarding volatile components, was investigated in four ripening stages. Ripening was characterized sensorily, as well as through physical and chemical analyses. Volatile compounds were isolated by a simultaneous distillation\\/solvent extraction method. Butanol, 3-methylbutanol, benzyl alcohol and ?-terpineol showed maximum concentrations in the third

Karina Almora; Jorge A. Pino; Mercedes Hernández; Cira Duarte; Juan González; Elda Roncal

2004-01-01

3

A male and hermaphrodite specific RAPD marker for papaya ( Carica papaya L.)  

Microsoft Academic Search

The random amplified polymorphic DNA (RAPD) technique was used to determine the sex of a dioecious species, Carica papaya L., with three sex types, male, female and hermaphrodite. A 450 bp marker fragment, named PSDM(Papaya Sex Determination Marker),\\u000a exists in all male and hermaphrodite plants but not in the female plants so far analyzed. The DNA sequence of PSDM exhibited

N. Urasaki; M. Tokumoto; K. Tarora; Y. Ban; T. Kayano; H. Tanaka; H. Oku; I. Chinen; R. Terauchi

2002-01-01

4

Erwinia mallotivora sp., a New Pathogen of Papaya (Carica papaya) in Peninsular Malaysia  

PubMed Central

Erwinia mallotivora was isolated from papaya infected with dieback disease showing the typical symptoms of greasy, water-soaked lesions and spots on leaves. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain belonged to the genus Erwinia and was united in a monophyletic group with E. mallotivora DSM 4565 (AJ233414). Earlier studies had indicated that the causal agent for this disease was E. papayae. However, our current studies, through Koch’s postulate, have confirmed that papaya dieback disease is caused by E. mallotivora. To our knowledge, this is the first new discovery of E. mallotivora as a causal agent of papaya dieback disease in Peninsular Malaysia. Previous reports have suggested that E. mallotivora causes leaf spot in Mallotus japonicus. However, this research confirms it also to be pathogenic to Carica papaya. PMID:21339975

Amin, Noriha Mat; Bunawan, Hamidun; Redzuan, Rohaiza Ahmad; Jaganath, Indu Bala S.

2011-01-01

5

Phospholipids of palash ( Butea monosperma ), papaya ( Carica papaya ), jangli badam ( Sterculia foetida ), coriander ( Coriandrum sativum ) and carrot ( Daucus carota ) seeds  

Microsoft Academic Search

Analyses of the phospholipids of palash(Butea monosperma), papaya(Carica papaya), jangli badam(Sterculia foetida), coriander(Coriandrum sativum) and carrot(Daucus carota) seeds are reported in the present study. Phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol were identified\\u000a as major components in all the seeds. Small amounts of lysophosphatidylcholine in palash and papaya, and cardiolipin in palash,\\u000a papaya and carrot also were detected. The predominant fatty acids present

R. B. N. Prasad; Y. Nagender Rao; S. Venkob Rao

1987-01-01

6

Physical-chemical analyses of irradiated papayas ( Carica papaya L.)  

NASA Astrophysics Data System (ADS)

Papaya is cultivated in Espírito Santo State/Brazil and as it stands up to irradiation, it is important to validate this technology, since it is already being applied in some countries. Penetration energy, ratio (relation between soluble solids and titrable acidity) and skin color were evaluated to verify the influence of four different doses of irradiation (0.0, 0.5, 0.75 and 1.00 kGy) on papayas, during 21 days. As a result for the skin color and the penetration energy, it was found that in the first days after irradiation, these variables increased with increase in radiation dose; however, after a time lapse, the tendency inverted and the irradiated fruits had a slower ripening process. For the ratio, a very important variable that it is responsible for the fruit taste, no difference was found between irradiated and the control fruit. Color and texture measurements are dependent on the storage temperature.

Camargo, R. J.; Tadini, C. C.; Sabato, S. F.

2007-11-01

7

Administration Dependent Antioxidant Effect of Carica papaya Seeds Water Extract  

PubMed Central

Carica papaya is widely used in folk medicine as herbal remedy to prevent, protect against, and cure several diseases. These curative properties are based on the presence in different parts of the plant of phytochemical nutrients with antioxidant effect. Seeds are the less exploited part; thus this study is aimed at assessing the antioxidant activities of the C. papaya seeds water extract against hydrogen peroxide (H2O2) oxidative stress in human skin Detroit 550 fibroblasts. C. papaya seeds water extract is not toxic and acts as a potent free radical scavenger, providing protection to Detroit 550 fibroblasts that underwent H2O2 oxidative stress. Data show that (i) the maximum protective effect is achieved by the simultaneous administration of the extract with 1?mM H2O2; (ii) the extract in presence of an oxidative stress does not increase catalase activity and prevents the release of cytochrome C and the inner mitochondrial transmembrane potential (??m) loss; (iii) the extract is more efficient than vitamin C to hamper the oxidative damage; (iv) the purified subfractions of the seeds water extract exert the same antioxidant effect of whole extract. In conclusion, C. papaya seeds water extract is potentially useful for protection against oxidative stress. PMID:24795765

Panzarini, Elisa; Dwikat, Majdi; Mariano, Stefania; Vergallo, Cristian; Dini, Luciana

2014-01-01

8

Novel thigmomorphogenetic responses in Carica papaya: touch decreases anthocyanin levels and stimulates petiole cork outgrowths  

PubMed Central

Background and Aims Because of its rapid growth rate, relative ease of transformation, sequenced genome and low gene number relative to Arabidopsis, the tropical fruit tree, Carica papaya, can serve as a complementary genetic model for complex traits. Here, new phenotypes and touch-regulated gene homologues have been identified that can be used to advance the understanding of thigmomorphogenesis, a multigenic response involving mechanoreception and morphological change. Methods Morphological alterations were quantified, and microscopy of tissue was conducted. Assays for hypocotyl anthocyanins, lignin and chlorophyll were performed, and predicted genes from C. papaya were compared with Arabidopsis touch-inducible (TCH) and Mechanosensitive channel of Small conductance-like genes (MscS-like or MSL). In addition, the expression of two papaya TCH1 homologues was characterized. Key Results On the abaxial side of petioles, treated plants were found to have novel, hypertrophic outgrowths associated with periderm and suberin. Touched plants also had higher lignin, dramatically less hypocotyl anthocyanins and chlorophyll, increased hypocotyl diameter, and decreased leaf width, stem length and root fresh weight. Papaya was found to have fewer MSL genes than Arabidopsis, and four touch-regulated genes in Arabidopsis had no counterparts in papaya. Water-spray treatment was found to enhance the expression of two papaya TCH1 homologues whereas induction following touch was only slightly correlated. Conclusions The novel petiole outgrowths caused by non-wounding, mechanical perturbation may be the result of hardening mechanisms, including added lignin, providing resistance against petiole movement. Inhibition of anthocyanin accumulation following touch, a new phenotypic association, may be caused by diversion of p-coumaroyl CoA away from chalcone synthase for lignin synthesis. The absence of MSL and touch-gene homologues indicates that papaya may have a smaller set of touch-regulated genes. The genes and novel touch-regulated phenotypes identified here will contribute to a more comprehensive view of thigmomorphogenesis in plants. PMID:19182220

Porter, Brad W.; Zhu, Yun J.; Webb, David T.; Christopher, David A.

2009-01-01

9

Revisiting the enzymes stored in the laticifers of Carica papaya in the context of their possible participation in the plant defence mechanism.  

PubMed

In the tropical species Carica papaya, the articulated and anastomosing laticifers form a dense network of vessels displayed in all aerial parts of the plant. Damaging the papaya tree inevitably severs its laticifers, eliciting an abrupt release of latex. Besides the well-known cysteine proteinases, papain, chymopapain, caricain and glycyl endopeptidase, papaya latex is also a rich source of other enzymes. Together, these enzymes could provide an important contribution to plant defence mechanisms by sanitising and sealing the wounded areas on the tree. PMID:11361091

El Moussaoui, A; Nijs, M; Paul, C; Wintjens, R; Vincentelli, J; Azarkan, M; Looze, Y

2001-04-01

10

Crystallization and preliminary X-ray diffraction studies of the glutaminyl cyclase from Carica papaya latex.  

PubMed

In living systems, the intramolecular cyclization of N-terminal glutamine residues is accomplished by glutaminyl cyclase enzymes (EC 2.3.2.5). While in mammals these enzymes are involved in the synthesis of hormonal and neurotransmitter peptides, the physiological role played by the corresponding plant enzymes still remains to be unravelled. Papaya glutaminyl cyclase (PQC), a 33 kDa enzyme found in the latex of the tropical tree Carica papaya, displays an exceptional resistance to chemical and thermal denaturation as well as to proteolysis. In order to elucidate its enzymatic mechanism and to gain insights into the structural determinants underlying its remarkable stability, PQC was isolated from papaya latex, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 62.82, b = 81.23, c = 108.17 A and two molecules per asymmetric unit. Diffraction data have been collected at ESRF beamline BM14 and processed to a resolution of 1.7 A. PMID:16508091

Azarkan, Mohamed; Clantin, Bernard; Bompard, Coralie; Belrhali, Hassan; Baeyens-Volant, Danielle; Looze, Yvan; Villeret, Vincent; Wintjens, René

2005-01-01

11

Crystallization and preliminary X-ray diffraction studies of the glutaminyl cyclase from Carica papaya latex  

PubMed Central

In living systems, the intramolecular cyclization of N-terminal glutamine residues is accomplished by glutaminyl cyclase enzymes (EC 2.3.2.5). While in mammals these enzymes are involved in the synthesis of hormonal and neurotransmitter peptides, the physiological role played by the corresponding plant enzymes still remains to be unravelled. Papaya glutaminyl cyclase (PQC), a 33?kDa enzyme found in the latex of the tropical tree Carica papaya, displays an exceptional resistance to chemical and thermal denaturation as well as to proteolysis. In order to elucidate its enzymatic mechanism and to gain insights into the structural determinants underlying its remarkable stability, PQC was isolated from papaya latex, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 62.82, b = 81.23, c = 108.17?Å and two molecules per asymmetric unit. Diffraction data have been collected at ESRF beamline BM14 and processed to a resolution of 1.7?Å. PMID:16508091

Azarkan, Mohamed; Clantin, Bernard; Bompard, Coralie; Belrhali, Hassan; Baeyens-Volant, Danielle; Looze, Yvan; Villeret, Vincent; Wintjens, Rene

2005-01-01

12

Purification and characterization of a wound-inducible thaumatin-like protein from the latex of Carica papaya.  

PubMed

A 22.137 kDa protein constituent of fresh latex was isolated both from the latex of regularly damaged papaya trees and from a commercially available papain preparation. The protein was purified up to apparent homogeneity and was shown to be absent in the latex of papaya trees that had never been previously mechanically injured. This suggests that the protein belongs to pathogenesis-related protein family, as expected for several other protein constituents of papaya latex. The protein was identified as a thaumatin-like protein (class 5 of the pathogenesis-related proteins) on the basis of its partial amino acid sequence. By sequence analysis of the Carica genome, three different forms of thaumatin-like protein were identified, where the latex constituent belongs to a well-known form, allowing the molecular modeling of its spatial structure. The papaya latex thaumatin-like protein was further characterized. The protein appears to be stable in the pH interval from 2 to 10 and resistant to chemical denaturation by guanidium chloride, with a DeltaG(water)(0) of 15.2 kcal/mol and to proteolysis by the four papaya cysteine proteinases. The physiological role of this protein is discussed. PMID:19527911

Looze, Yvan; Boussard, Paule; Huet, Joëlle; Vandenbusche, Guy; Vandenbussche, Guy; Azarkan, Mohamed; Raussens, Vincent; Wintjens, René

2009-05-01

13

Control Biológico de Colletotrichum gloeosporioides ((Penz.) Penz. y Sacc.) en Papaya Maradol Roja (Carica papaya L.) y Fisiología Postcosecha de Frutos Infectados  

Microsoft Academic Search

Three and four isolates of the antagonistic bacteria Bacillus firmus and Pseudomonas fluorescens, respectively, as well as plant extracts with fungitoxic properties were evaluated for the biological control of anthracnose (Colletotrichum gloeosporioides). Also, the effects of the disease on some physical, chemical, and physiological characteristics of papaya fruits Maradol Roja (Carica papaya) were evaluated. In vitro, only two strains of

Emma Zavaleta-Mejía; Isaac Luna-Romero; Casco de Santo Tomás; Juan Gabriel Gutiérrez-Alonso

2004-01-01

14

Inhibitive action of Carica papaya extracts on the corrosion of mild steel in acidic media and their adsorption characteristics  

Microsoft Academic Search

Purpose – To evaluate the effect of different parts of Carica papaya (leaves (LV), seeds (SD), heart wood (HW) and bark (BK)) as eco-friendly and non-toxic mild-steel corrosion inhibitors in H2SO4 at 30 to 60 oC. Design\\/methodology\\/approach – Acid extracts of the different parts of Carica papaya were used as inhibitors in various corrosion tests. Gravimetric and gasometric techniques were

P. C. Okafor; E. E. Ebenso

2007-01-01

15

Antifungal Activity in Ethanolic Extracts of Carica papaya L. cv. Maradol Leaves and Seeds.  

PubMed

Bioactive compounds from vegetal sources are a potential source of natural antifungic. An ethanol extraction was used to obtain bioactive compounds from Carica papaya L. cv. Maradol leaves and seeds of discarded ripe and unripe fruit. Both, extraction time and the papaya tissue flour:organic solvent ratio significantly affected yield, with the longest time and highest flour:solvent ratio producing the highest yield. The effect of time on extraction efficiency was confirmed by qualitative identification of the compounds present in the lowest and highest yield extracts. Analysis of the leaf extract with phytochemical tests showed the presence of alkaloids, flavonoids and terpenes. Antifungal effectiveness was determined by challenging the extracts (LE, SRE, SUE) from the best extraction treatment against three phytopathogenic fungi: Rhizopus stolonifer, Fusarium spp. and Colletotrichum gloeosporioides. The leaf extract exhibited the broadest action spectrum. The MIC(50) for the leaf extract was 0.625 mg ml(-1) for Fusarium spp. and >10 mg ml(-1) for C. gloeosporioides, both equal to approximately 20% mycelial growth inhibition. Ethanolic extracts from Carica papaya L. cv. Maradol leaves are a potential source of secondary metabolites with antifungal properties. PMID:22282629

Chávez-Quintal, Pedro; González-Flores, Tania; Rodríguez-Buenfil, Ingrid; Gallegos-Tintoré, Santiago

2011-01-01

16

Morphological study of bone marrow to assess the effects of lead acetate on haemopoiesis and aplasia and the ameliorating role of Carica papaya extract  

PubMed Central

Lead causes damage to the body by inducing oxidative stress. The sites of damage include the bone marrow, where marrow hypoplasia and osteosclerosis may be observed. Leaves of Carica papaya, which have antioxidant and haemopoietic properties, were tested against the effect of lead acetate in experimental rats. The rats were divided into 8 groups; control, lead acetate only, Carica papaya (50 mg and 200 mg), post-treatment with Carica papaya (50 mg and 200 mg) following lead acetate administration and pre-treatment with Carica papaya (50 mg and 200 mg) followed by lead acetate administration. The substances were administered for 14 days. The effects were evaluated by measuring protein carbonyl content (PCC) and glutathione content (GC) in the bone marrow. Histological changes in the bone marrow were also observed. The results showed that Carica papaya induced a significant reduction in the PCC activity and significantly increased the GC in the bone marrow. Carica papaya also improved the histology of the bone marrow compared with that of the lead acetate-treated group. In summary, Carica papaya was effective against the oxidative damage caused by lead acetate in the bone marrow and had a stimulatory effect on haemopoiesis. PMID:23403524

THAM, CHING S.; CHAKRAVARTHI, SRIKUMAR; HALEAGRAHARA, NAGARAJA; DE ALWIS, RANJIT

2013-01-01

17

Complete nucleotide sequence of a monopartite Begomovirus and associated satellites infecting Carica papaya in Nepal.  

PubMed

Carica papaya (papaya) is a fruit crop that is cultivated mostly in kitchen gardens throughout Nepal. Leaf samples of C. papaya plants with leaf curling, vein darkening, vein thickening, and a reduction in leaf size were collected from a garden in Darai village, Rampur, Nepal in 2010. Full-length clones of a monopartite Begomovirus, a betasatellite and an alphasatellite were isolated. The complete nucleotide sequence of the Begomovirus showed the arrangement of genes typical of Old World begomoviruses with the highest nucleotide sequence identity (>99 %) to an isolate of Ageratum yellow vein virus (AYVV), confirming it as an isolate of AYVV. The complete nucleotide sequence of betasatellite showed greater than 89 % nucleotide sequence identity to an isolate of Tomato leaf curl Java betasatellite originating from Indonesian. The sequence of the alphasatellite displayed 92 % nucleotide sequence identity to Sida yellow vein China alphasatellite. This is the first identification of these components in Nepal and the first time they have been identified in papaya. PMID:23397078

Shahid, M S; Yoshida, S; Khatri-Chhetri, G B; Briddon, R W; Natsuaki, K T

2013-06-01

18

Correct names for some of the closest relatives of Carica papaya: A review of the Mexican/Guatemalan genera Jarilla and Horovitzia  

PubMed Central

Abstract Using molecular data, we recently showed that Carica papaya L. is sister to a Mexican/Guatemalan clade of two genera, Jarilla Rusby with three species and Horovitzia V.M. Badillo with one. These species are herbs or thin-stemmed trees and may be of interest for future genomics-enabled papaya breeding. Here we clarify the correct names of Jarilla heterophylla (Cerv. ex La Llave) Rusby and Jarilla caudata (Brandegee) Standl., which were confused in a recent systematic treatment of Jarilla (McVaugh 2001). We designate epitypes for both, provide weblinks to type specimens, a key to the species of Jarilla and Horovitzia, and notes on their habitats and distribution. PMID:24399895

Carvalho, Fernanda Antunes; Renner, Susanne S.

2013-01-01

19

Production of fatty acid butyl esters using the low cost naturally immobilized Carica papaya lipase.  

PubMed

In this work, the low cost naturally immobilized Carica papaya lipase (CPL) was investigated for production of fatty acid butyl esters (FABE) to fulfill the aim of reducing the lipase cost in the enzymatic butyl-biodiesel process. The CPL showed specificities to different alcohol acyl acceptors. Alcohols with more than three carbon atoms did not have negative effects on the CPL activity. The CPL catalyzed butanolysis for FABE production was systematically investigated. The reaction solvent, alcohol/oil molar ratio, enzyme amount, reaction temperature, and water activity all affected the butanolysis process. Under the optimized conditions, the highest conversion of 96% could be attained in 24 h. These optimal conditions were further applied to CPL catalyzed butanolysis of other vegetable oils. All of them showed very high conversion. The CPL packed-bed reactor was further developed, and could be operated continuously for more than 150 h. All of these results showed that the low cost Carica papaya lipase can be used as a promising lipase for biodiesel production. PMID:24954104

Su, Erzheng; Wei, Dongzhi

2014-07-01

20

Development of a Gene-Centered SSR Atlas as a Resource for Papaya (Carica papaya) Marker-Assisted Selection and Population Genetic Studies  

PubMed Central

Carica papaya (papaya) is an economically important tropical fruit. Molecular marker-assisted selection is an inexpensive and reliable tool that has been widely used to improve fruit quality traits and resistance against diseases. In the present study we report the development and validation of an atlas of papaya simple sequence repeat (SSR) markers. We integrated gene predictions and functional annotations to provide a gene-centered perspective for marker-assisted selection studies. Our atlas comprises 160,318 SSRs, from which 21,231 were located in genic regions (i.e. inside exons, exon-intron junctions or introns). A total of 116,453 (72.6%) of all identified repeats were successfully mapped to one of the nine papaya linkage groups. Primer pairs were designed for markers from 9,594 genes (34.5% of the papaya gene complement). Using papaya-tomato orthology assessments, we assembled a list of 300 genes (comprising 785 SSRs) potentially involved in fruit ripening. We validated our atlas by screening 73 SSR markers (including 25 fruit ripening genes), achieving 100% amplification rate and uncovering 26% polymorphism rate between the parental genotypes (Sekati and JS12). The SSR atlas presented here is the first comprehensive gene-centered collection of annotated and genome positioned papaya SSRs. These features combined with thousands of high-quality primer pairs make the atlas an important resource for the papaya research community. PMID:25393538

Vidal, Newton Medeiros; Grazziotin, Ana Laura; Ramos, Helaine Christine Cancela; Pereira, Messias Gonzaga; Venancio, Thiago Motta

2014-01-01

21

Bioseparation of papain from Carica papaya latex by precipitation of papain-poly (vinyl sulfonate) complexes.  

PubMed

The formation of insoluble complexes between enzymes and polyelectrolytes is a suitable technique for isolating these biomolecules from natural sources, because it is a simple and rapid technique that allows the concentration of the protein. This technique can be used in most purification protocols at the beginning of the downstream process. The aim of this investigation is to isolate papain from Carica papaya latex by precipitation of insoluble complexes between this enzyme and poly (vinyl sulfonate). The papain-poly (vinyl sulfonate) complex was insoluble at pH lower than 6, with a PVS/PAP stoichiometric ratio of 1:279. Ionic strength affected the complex formation. The presence of the polymer increased the enzymatic activity and protected the enzyme from autodegradation. The optimal conditions for the formation of insoluble papain-polyelectrolyte complex formation were applied to C. papaya latex and a high recovery was obtained (around 86%) and a purification factor around 2. This method can be applied as an isolation method of papain from C. papaya latex or as a first step in a larger purification strategy. PMID:23891572

Braia, Mauricio; Ferrero, Maximiliano; Rocha, María Victoria; Loureiro, Dana; Tubio, Gisela; Romanini, Diana

2013-09-01

22

Sex and ploidy of anther culture derived papaya ( Carica papaya L.) plants  

Microsoft Academic Search

Summary  To improve the efficiency of papaya anther culture, we investigated (1) hormonal medium conditions for inducing haploids or dihaploids; (2) identified the sex of established plantlets using a sex-specific DNA molecular marker and (3) estimated their ploidy by flow cytometry analysis of DNA content. Anthers with a mixture of uninucleate, mitotic, and binucleate microspores were collected from a male plant,

Fredah K. Rimberia; Shinichi Adaniya; Takeomi Etoh; Yukio Ishimine

2006-01-01

23

Cysteine proteinases from papaya (Carica papaya) in the treatment of experimental Trichuris suis infection in pigs: two randomized controlled trials  

PubMed Central

Background Cysteine proteinases (CPs) from papaya (Carica papaya) possess anthelmintic properties against human soil-transmitted helminths (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm), but there is a lack of supportive and up-to-date efficacy data. We therefore conducted two randomized controlled trials in pigs to assess the efficacy of papaya CPs against experimental infections with T. suis. Methods First, we assessed efficacy by means of egg (ERR) and adult worm reduction rate (WRR) of a single-oral dose of 450 ?mol active CPs (CP450) against low (inoculum of 300 eggs) and high (inoculum of 3,000 eggs) intensity T. suis infections and compared the efficacy with those obtained after a single-oral dose of 400 mg albendazole (ALB). In the second trial, we determined and compared the efficacy of a series of CP doses (45 [CP45], 115 [CP115], 225 [CP225], and 450 [CP450] ?mol) against high intensity infections. Results CP450 was highly efficacious against both levels of infection intensity, resulting in ERR and WRR of more than 97%. For both levels of infection intensity, CP450 was significantly more efficacious compared to ALB by means of WRR (low infection intensity: 99.0% vs. 39.0%; high infection intensity; 97.4% vs. 23.2%). When the efficacy was assessed by ERR, a significant difference was only observed for high intensity infections, CP450 being more efficacious than ALB (98.9% vs. 59.0%). For low infection intensities, there was no significant difference in ERR between CP450 (98.3%) and ALB (64.4%). The efficacy of CPs increased as a function of increasing dose. When determined by ERR, the efficacy ranged from 2.1% for CP45 to 99.2% for CP450. For WRR the results varied from -14.0% to 99.0%, respectively. Pairwise comparison revealed a significant difference in ERR and WRR only between CP45 and CP450, the latter being more efficacious. Conclusions A single dose of 450 ?mol CPs provided greater efficacy against T. suis infections in pigs than a single-oral dose of 400 mg ALB. Although these results highlight the possibility of papaya CPs for controlling human STH, further development is needed in order to obtain and validate an oral formulation for human application. PMID:24886388

2014-01-01

24

'Candidatus Phytoplasma graminis' and 'Candidatus Phytoplasma caricae', two novel phytoplasmas associated with diseases of sugarcane, weeds and papaya in Cuba.  

PubMed

During 2003, surveys of sugarcane yellow leaf disease and papaya bunchy top-like disease were carried out on plantations in Havana province, Cuba, to determine the roles of weeds and Auchenorrhyncha insects in the epidemiology of these diseases. More than 250 plant and insect samples were collected and indexed by using a nested PCR for phytoplasma 16S rDNA with the generic primer pairs P1/P7 and R16F2n/R16R2. The PCR products were further characterized by restriction fragment length polymorphism using HaeIII, AluI, Sau3AI, Tru9I, HhaI, HpaII and TaqI endonucleases, giving patterns that distinguished them from those of the other reference phytoplasmas analysed. Phylogenetic analysis of 16S rRNA gene sequences identified the phytoplasmas present in sugarcane (Saccharum officinarum L.), Cynodon dactylon L., Conyza canadensis L. Cronq., Sorghum halepense L. Pers., Macroptilium lathyroides L. Urb., Saccharosydne saccharivora (Westwood) and Cedusa spp., and those in papaya (Carica papaya L.) and Empoasca papayae, as two novel provisional phytoplasma species. We propose that these phytoplasmas should be given Candidatus status, as 'Candidatus Phytoplasma graminis' and 'Candidatus Phytoplasma caricae', respectively. PMID:16280510

Arocha, Yaima; López, Mercedes; Piñol, Berta; Fernández, Miriam; Picornell, Buenaventura; Almeida, Roberto; Palenzuela, Iris; Wilson, Michael R; Jones, Phil

2005-11-01

25

Pichia cecembensis sp. nov. isolated from a papaya fruit (Carica papaya L., Caricaceae).  

PubMed

The ascogenous yeast YS16T was isolated from a decaying papaya fruit. Phenotypic traits such as multilateral budding, spheroidal or elongate shape, pseudohyphae formation, asci with one or more ascospores, ability to ferment d-glucose, inability to assimilate nitrate and the presence of Q7 ubiquinone suggest its affiliation to the genus Pichia. The nearest phylogenetic neighbor, based on D1/D2 domain sequence of the 26S rRNA gene and ITS region sequence, was identified as Issatchenkia orientalis (NRRL Y-5396T, a synonym of Pichia kudriavzevii) with similarities of 98.2% and 97% respectively. In addition to the difference in the D1/D2 and ITS region sequence, YS16T differs from I. orientalis with respect to a number of phenotypic traits. However, in the phylogenetic analysis, YS16T showed close relatedness to the P. membranifaciens clade. Thus, it is proposed to assign the status of a new species to YS16T, for which the name P. cecembensis sp. nov. is proposed. The type strain of P. cecembensis sp. nov. is YS16T (=NRRL Y-27985T=JCM 13873T=CBS 10445T). PMID:17316366

Bhadra, Bhaskar; Sreenivas Rao, R; Naveen Kumar, N; Chaturvedi, Preeti; Sarkar, Partha K; Shivaji, S

2007-06-01

26

ANTIOXIDANT AND IMMUNOSTIMULANT EFFECT OF CARICA PAPAYA LINN. AQUEOUS EXTRACT IN ACRYLAMIDE INTOXICATED RATS  

PubMed Central

Introduction: The present study was conducted to evaluate the antioxidant and immunostimulant effects of The Carica papaya fruit aqueous extract (CPF, Caricaceae) against acrylamide induced oxidative stress and improvement of Immune functions which affected by free radicals liberating acrylamide in rats. Material and methods: Sixty male wistar albino rats (195-230g) were assigned to four groups, (fifteen/group). The first group used as control group and received normal physiological saline orally daily. The second group was supplemented with acrylamide 0.05% in drinking water. The third group was gastro-gavaged with 250 mg/kg of papaya fruit extract orally on daily basis. The fourth group was supplemented with acrylamide 0.05% in drinking water and gastro-gavaged with 250 mg/kg of papaya fruit extract orally on daily basis. The chosen dose of papaya fruit extract was based on the active pharmacological dose range obtained from the orientation study earlier conducted. The experimental period was extended to forty day. At the expiration of the experimental period and night fasting, blood samples were collected from the orbital venous sinus. The sera were separated and used for determining of IgG and IgM and the stomach, liver and kidney homogenates for estimation of MDA, GSH level, SOD and CAT activity as a biomarker of lipid peroxidation and antioxidative stress. Results and discussion: The obtained results revealed that, acrylamide caused significant increases in MDA and decrease of GSH level, SOD and CAT activity due to the oxidative stress induced by acrylamide on membrane polyunsaturated fatty acids in rat’s stomach, liver and kidney while administration of CPF aqueous extract, was significantly ameliorated the increased levels of MDA and decline of GSH, SOD and CAT activity in the stomach, liver and kidney tissues caused by acrylamide toxicity. Meanwhile, CPF aqueous extract significantly increased immune functions (IgG and IgM) while acrylamide significantly decrease it specially IgG. Thus, this study suggests that acrylamide-induced oxidative stress in rats can be ameliorated by administration of CPF aqueous extract. PMID:23322975

Mohamed Sadek, Kadry

2012-01-01

27

Binary Combination of Carica papaya, Areca catechu and Myristica fragrans with Piperonyl Butoxide / MGK-264 against Freshwater Snail Lymnaea acuminata.  

PubMed

Piperonyl butoxide (PB) and MGK-264 were used to enhance the toxicity of the active components papain, arecoline and myristicin from the plants Carica papaya, Areca catechu and Myristica fragrans, respectively, against the vector snail Lymnaea acuminata. A time- and dose-dependent relationship was observed for the toxicity of these combinations. The toxic effects of these plant-derived molluscicides in combination with the synergists PB and MGK-264 were several times higher than the effect of the individual treatments. The highest degree of synergism was observed when MGK-264 was used in combination with C. papaya latex (10.47-fold increase) and PB was used with papain (8.35-fold increase). PMID:24575245

Hanif, Farhat; Singh, Dinesh Kumar

2013-12-01

28

Binary Combination of Carica papaya, Areca catechu and Myristica fragrans with Piperonyl Butoxide / MGK-264 against Freshwater Snail Lymnaea acuminata  

PubMed Central

Piperonyl butoxide (PB) and MGK-264 were used to enhance the toxicity of the active components papain, arecoline and myristicin from the plants Carica papaya, Areca catechu and Myristica fragrans, respectively, against the vector snail Lymnaea acuminata. A time- and dose-dependent relationship was observed for the toxicity of these combinations. The toxic effects of these plant-derived molluscicides in combination with the synergists PB and MGK-264 were several times higher than the effect of the individual treatments. The highest degree of synergism was observed when MGK-264 was used in combination with C. papaya latex (10.47-fold increase) and PB was used with papain (8.35-fold increase). PMID:24575245

Hanif, Farhat; Singh, Dinesh Kumar

2013-01-01

29

Revisiting the enzymes stored in the laticifers of C arica papaya in the context of their possible participation in the plant defence mechanism  

Microsoft Academic Search

In the tropical species Carica papaya, the articulated and anastomosing laticifers form a dense network of vessels displayed in all aerial parts of the plant. Damaging the papaya tree inevitably severs its laticifers, eliciting an abrupt release of latex. Besides the well-known cysteine proteinases, papain, chymopapain, caricain and glycyl endopeptidase, papaya latex is also a rich source of other enzymes.

A. El Moussaoui; M. Nijs; C. Paul; R. Wintjens; J. Vincentelli; M. Azarkan; Yvan Looze

2001-01-01

30

Crystallization and preliminary X-ray analysis of a family 19 glycosyl hydrolase from Carica papaya latex.  

PubMed

A chitinase isolated from the latex of the tropical species Carica papaya has been purified to homogeneity and crystallized. This enzyme belongs to glycosyl hydrolase family 19 and exhibits exceptional resistance to proteolysis. The initially observed crystals, which diffracted to a resolution of 2.0 A, were improved through modification of the crystallization protocol. Well ordered crystals were subsequently obtained using N-acetyl-D-glucosamine, the monomer resulting from the hydrolysis of chitin, as an additive to the crystallization solution. Here, the characterization of a chitinase crystal that belongs to the monoclinic space group P2(1), with unit-cell parameters a = 69.08, b = 44.79, c = 76.73 A, beta = 95.33 degrees and two molecules per asymmetric unit, is reported. Diffraction data were collected to a resolution of 1.8 A. Structure refinement is currently in progress. PMID:18453704

Huet, Joëlle; Azarkan, Mohamed; Looze, Yvan; Villeret, Vincent; Wintjens, René

2008-05-01

31

Crystallization and preliminary X-ray analysis of a family 19 glycosyl hydrolase from Carica papaya latex  

PubMed Central

A chitinase isolated from the latex of the tropical species Carica papaya has been purified to homogeneity and crystallized. This enzyme belongs to glycosyl hydrolase family 19 and exhibits exceptional resistance to proteolysis. The initially observed crystals, which diffracted to a resolution of 2.0?Å, were improved through modification of the crystallization protocol. Well ordered crystals were subsequently obtained using N-acetyl-d-glucosamine, the mono­mer resulting from the hydrolysis of chitin, as an additive to the crystallization solution. Here, the characterization of a chitinase crystal that belongs to the monoclinic space group P21, with unit-cell parameters a = 69.08, b = 44.79, c = 76.73?Å, ? = 95.33° and two molecules per asymmetric unit, is reported. Diffraction data were collected to a resolution of 1.8?Å. Structure refinement is currently in progress. PMID:18453704

Huet, Joelle; Azarkan, Mohamed; Looze, Yvan; Villeret, Vincent; Wintjens, Rene

2008-01-01

32

Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation.  

PubMed

Copper oxide (CuO) nanoparticles were synthesized by treating 5 mM cupric sulphate with Carica papaya leaves extract. The kinetics of the reaction was studied using UV-visible spectrophotometry. An intense surface Plasmon resonance between 250-300 nm in the UV-vis spectrum clearly reveals the formation of copper oxide nanoparticles. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) exhibited that the green synthesized copper oxide nanoparticles are rod in shape and having a mean particle size of 140 nm, further negative zeta potential disclose its stability at -28.9 mV. The Fourier-transform infrared (FTIR) spectroscopy results examined the occurrence of bioactive functional groups required for the reduction of copper ions. X-ray diffraction (XRD) spectra confirmed the copper oxide nanoparticles crystalline nature. Furthermore, colloidal copper oxide nanoparticles effectively degrade the Coomassie brilliant blue R-250 dye beneath the sunlight. PMID:24388701

Sankar, Renu; Manikandan, Perumal; Malarvizhi, Viswanathan; Fathima, Tajudeennasrin; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

2014-01-01

33

Preliminary in vitro antisickilng properties of crude juice extracts of Persia Americana, Citrus sinensis, Carica papaya and Ciklavit®.  

PubMed

The antisickling properties of crude juice extracts of the edible portions of three commonly consumed tropical fruits namely Persia americana, Citrus sinensis, and Carica papaya were investigated in vitro alongside a new drug preparation called Ciklavit® that has antisickling activity. Four different solvent extracts of the crude juice of each fruit including aqueous, acidic, alkaline and alcoholic extracts were prepared and their antisickling effects on sickle cell trait (HbAS) and sickle cell disease (HbSS) blood samples checked alongside Ciklavit®. Blood samples were stabilized using normal saline and the antisickling effects were checked by counting the number of sickle cells remaining after incubation of the blood samples with the crude fruit extracts and Ciklavit® for twenty-four hours. The results showed that Ciklavit® produced a sustained reduction in the number of sickle cells in both HbAS and HbSS blood samples. Also the alkaline and alcoholic extracts of P. americana and C. papaya produced significant reduction in the number of sickle cells. PMID:21304622

Iweala, E E J; Uhegbu, F O; Ogu, G N

2010-01-01

34

Nephroprotective activities of the aqueous seed extract of Carica papaya Linn. in carbon tetrachloride induced renal injured Wistar rats: a dose- and time-dependent study  

Microsoft Academic Search

In the present study, the dose related effect of the aqueous seed extract of Carica papaya Linn. extract (CPE) was evaluated by pre-treating three groups of rats (made up of six male rats per group) with 100 - 400 mg\\/kg body weight per oral of the extract for 7 days before challenging with 1.5 ml\\/kg body weight of 20% carbon

JA Olagunju; AA Adeneye; AG Adeleke

35

Does Carica papaya leaf-extract increase the platelet count? An experimental study in a murine model  

PubMed Central

Objective To investigate the potential role of fresh Carica papaya (C. papaya) leaf extract on haematological and biochemical parameters and toxicological changes in a murine model. Methods In total 36 mice were used for the trial. Fresh C. papaya leaf extract [0.2 mL (2 g)/mouse] was given only to the test group (18 mice). General behavior, clinical signs and feeding patterns were recorded. Blood and tissue samples were collected at intervals. Haematological parameters including platelet, red blood cell (RBC), white blood cell (WBC), packed cell volume (PCV), serum biochemistry including serum creatinine, serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) were determined. Organs for possible histopathological changes were examined. Results Neither group exhibited alteration of behavior or reduction in food and water intake. Similarly, no significant changes in SGOT, SGPT and serum creatinine levels were detected in the test group. Histopathological organ changes were not observed in either group of mice except in three liver samples of the test group which had a mild focal necrosis. The platelet count (11.33±0.35)×105/µL (P=0.000?04) and the RBC count (7.97±0.61)×106/µL (P=0.000?03) were significantly increased in the test group compared to that of the controls. However, WBC count and PCV (%) values were not changed significantly in the test group. The platelet count in the test group started to increase significantly from Day 3 (3.4±0.18×105/µL), reaching almost a fourfold higher at Day 21 (11.3×105/µL), while it was 3.8×105/µL and 5.5×105/µL at Day 3 and Day 21 respectively in the control. Likewise, the RBC count in the test group increased from 6×106/µL to 9×106/ µL at Day 21 while it remained near constant in the control group (6×106/µL). Conclusions Fresh C. papaya leaf extract significantly increased the platelet and RBC counts in the test group as compared to controls. Therefore, it is very important to identify those chemicals of C. papaya leaves as it can be recommended to be used as a medication to boost thrombopoiesis and erythropoiesis in humans and in animals in which these cell lineages have been compromised. PMID:23998013

Dharmarathna, Sinhalagoda Lekamlage Chandi Asoka; Wickramasinghe, Susiji; Waduge, Roshitha Nilmini; Rajapakse, Rajapakse Peramune Veddikkarage Jayanthe; Kularatne, Senanayake Abeysinghe Mudiyanselage

2013-01-01

36

Antioxidant and Anti-Inflammatory Activities of Extracts from Cassia alata, Eleusine indica, Eremomastax speciosa, Carica papaya and Polyscias fulva Medicinal Plants Collected in Cameroon  

PubMed Central

Background The vast majority of the population around the world has always used medicinal plants as first source of health care to fight infectious and non infectious diseases. Most of these medicinal plants may have scientific evidence to be considered in general practice. Objective The aim of this work was to investigate the antioxidant capacities and anti-inflammatory activities of ethanol extracts of leaves of Cassia alata, Eleusine indica, Carica papaya, Eremomastax speciosa and the stem bark of Polyscias fulva, collected in Cameroon. Methods Chemiluminescence was used to analyze the antioxidant activities of plant extracts against hydrogen peroxide or superoxide anion. Comet assays were used to analyze the protection against antioxidant-induced DNA damage induced in white blood cells after treating with hydrogen peroxide. Flow cytometry was used to measure ?? T cells proliferation and anti-inflammatory activity of ?? T cells and of immature dendritic cells (imDC) in the presence of different concentrations of plant extracts. Results Ethanol extracts showed strong antioxidant properties against both hydrogen peroxide and superoxide anion. Cassia alata showed the highest antioxidant activity. The effect of plant extracts on ?? T cells and imDC was evidenced by the dose dependent reduction in TNF-? production in the presence of Cassia alata, Carica papaya, Eremomastax speciosa Eleusine indica, and Polyscias fulva. ?? T cells proliferation was affected to the greatest extent by Polyscias fulva. Conclusion These results clearly show the antioxidant capacity and anti-inflammatory activities of plant extracts collected in Cameroon. These properties of leaves and stem bark extracts may contribute to the value for these plants in traditional medicine and in general medical practice. PMID:25090613

Sagnia, Bertrand; Fedeli, Donatella; Casetti, Rita; Montesano, Carla; Falcioni, Giancarlo; Colizzi, Vittorio

2014-01-01

37

In Vivo Antiprotozoal Activity of the Chloroform Extract from Carica papaya Seeds against Amastigote Stage of Trypanosoma cruzi during Indeterminate and Chronic Phase of Infection  

PubMed Central

In order to evaluate the antiprotozoal activity of the chloroform extract of Carica papaya seeds during the subacute and chronic phase of infection of Trypanosoma cruzi, doses of 50 and 75?mg/kg were evaluated during the subacute phase, including a mixture of their main components (oleic, palmitic, and stearic acids). Subsequently, doses of 50 and 75?mg/kg in mice during the chronic phase of infection (100?dpi) were also evaluated. It was found that chloroform extract was able to reduce the amastigote nests numbers during the subacute phase in 55.5 and 69.7% (P > 0.05) as well as in 56.45% in animals treated with the mixture of fatty acids. Moreover, the experimental groups treated with 50 and 75?mg/kg during the chronic phase of the infection showed a significant reduction of 46.8 and 53.13% respectively (P < 0.05). It is recommended to carry out more studies to determine if higher doses of chloroformic extract or its administration in combination with other antichagasic drugs allows a better response over the intracellular stage of T. cruzi in infected animal models and determine if the chloroform extract of C. papaya could be considered as an alternative for treatment during the indeterminate and chronic phase of the infection. PMID:25276216

Ortega-Pacheco, Antonio; Perez-Gutierrez, Salud; Guzman-Marin, Eugenia

2014-01-01

38

Bioefficacy of larvicdial and pupicidal properties of Carica papaya (Caricaceae) leaf extract and bacterial insecticide, spinosad, against chikungunya vector, Aedes aegypti (Diptera: Culicidae).  

PubMed

The present study was carried out to establish the properties of Carica papaya leaf extract and bacterial insecticide, spinosad on larvicidal and pupicidal activity against the chikungunya vector, Aedes aegypti. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. C. papaya leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder (500 g) of the leaf was extracted with 1.5 l of organic solvents of methanol for 8 h using a Soxhlet apparatus and then filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; however, the highest larval and pupal mortality was found in the leaf extract of methanol C. papaya against the first- to fourth-instar larvae and pupae of values LC(50)?=?I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 440.65 ppm, respectively, and bacterial insecticide, spinosad against the first to fourth instar larvae and pupae of values LC(50)?=?I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 93.44 ppm, respectively. Moreover, combined treatment of values of LC(50)?=?I instar was 55.77 ppm, II instar was 65.77 ppm, III instar was 76.36 ppm, and IV instar was 92.78 ppm, and pupae was 107.62 ppm, respectively. No mortality was observed in the control. The results that the leaves extract of C. papaya and bacterial insecticide, Spinosad is promising as good larvicidal and pupicidal properties of against chikungunya vector, A. aegypti. This is an ideal eco-friendly approach for the control of chikungunya vector, A. aegypti as target species of vector control programs. PMID:21750871

Kovendan, Kalimuthu; Murugan, Kadarkarai; Naresh Kumar, Arjunan; Vincent, Savariar; Hwang, Jiang-Shiou

2012-02-01

39

Solenostemon monostachyus, Ipomoea involucrata and Carica papaya seed oil versus Glutathione, or Vernonia amygdalina: Methanolic extracts of novel plants for the management of sickle cell anemia disease  

PubMed Central

Background Sickle cell disease (SCD) is a genetic disease caused by an individual inheriting an allele for sickle cell hemoglobin from both parents and is associated with unusually large numbers of immature blood cells, containing many long, thin, crescent-shaped erythrocytes. It is a disease prevalent throughout many populations. The use of medicinal plants and nutrition in managing SCD is gaining increasing attention. Methods The antisickling effects of Solenostemon monostachyus (SolMon), Carica papaya seed oil (Cari-oil) and Ipomoea involucrata (Ipocrata) in male (HbSSM) and female (HbSSF) human sickle cell blood was examined in vitro and compared with controls, or cells treated with glutathione or an antisickling plant (Vernonia amygdalina; VerMyg). Results Levels of sickle blood cells were significantly reduced (P < 0.05) in all the plant-extract treated SCD patients’ blood compared with that of untreated SCD patients. RBCs in SolMon, Ipocrata, and Cari-oil treated samples were significantly higher (P < 0.05) compared with VerMyg-treated samples. The Fe2+/Fe3+ ratio was significantly reduced (P < 0.05) in all plant extract-treated HbSSM samples compared with controls. Hemoglobin concentration was significantly increased (P < 0.05) by SolMon treatment in HbSSF compared with VerMyg. Sickle cell polymerization inhibition exhibited by SolMon was significantly higher (P < 0.05) compared with that of VerMyg in HbSSF blood. Sickle cell polymerization inhibition in SolMon and Ipocrata were significantly higher (P < 0.05) compared with VerMyg in HbSSM blood. All plant extracts significantly reduced (P < 0.05) lactate dehydrogenase activity in both HbSSM and HbSSF-treated blood. Catalase activity was significantly increased (P < 0.05) in HbSSF blood treated with Ipocrata compared with glutathione. Cari-oil treated HbSSM and HbSSF blood had significantly increased (P < 0.05) peroxidase activity compared with controls. Conclusions Methanolic extracts from S. monostachyus, C. papaya seed oil and I. involucrata exhibited particular antisickling properties coupled with the potential to reduce stress in sickle cell patients. Each plant individually or in combination may be useful for the management of sickle cell disease. PMID:23259718

2012-01-01

40

Nutritional composition of Rainbow papaya, the first commercialized transgenic fruit crop  

Microsoft Academic Search

Rainbow papaya (Carica papaya L.) is a genetically engineered (GE) cultivar with resistance to papaya ringspot virus (PRSV). This cultivar currently accounts for about 70% of Hawaii's papaya acreage. The nutritional composition of Rainbow papaya and a non-transgenic control were analyzed to address GE food safety concerns regarding the potential for altered nutritional composition and altered expression of inherent allergens

Savarni Tripathi; Jon Y. Suzuki; James B. Carr; Grant T. McQuate; Stephen A. Ferreira; Richard M. Manshardt; Karen Y. Pitz; Marisa M. Wall; Dennis Gonsalves

2011-01-01

41

Stability studies of papaya pectinesterase  

Microsoft Academic Search

Stability studies were carried out on the purified papaya (Carica papaya L. var. exotica) pectinesterase (EC 3.1.1.11). The enzyme preparation was stable at 4°C in 0·02m sodium phosphate buffer (pH 7·5) solution containing 0·2m NaCl and 0·02% sodium azide and the loss in activity was less than 5% after storage for 1 year. The thermostability studies showed that enzyme was

A Fayyaz; B. A Asbi; H. M Ghazali; Y. B Che Man; S Jinap

1995-01-01

42

Ripening in papaya fruit is altered by ACC oxidase cosuppression  

Microsoft Academic Search

Papaya (Carica papaya) is a very important crop in many tropical countries but it is highly susceptible to parasitic diseases, physiological disorders,\\u000a mechanical damage and fruit overripening. Here we report a study on ACC oxidase cosuppression and its effects on papaya fruit\\u000a ripening. Papaya ACC oxidase was isolated using PCR and embriogenic cells transformed by biolistic using the CaMV 35S

Rodolfo López-Gómez; Jose Luis Cabrera-Ponce; Luis Jorge Saucedo-Arias; Lorena Carreto-Montoya; Ramon Villanueva-Arce; Juan Carlos Díaz-Perez; Miguel Angel Gómez-Lim; Luis Herrera-Estrella

2009-01-01

43

Ex vivo and in vivo investigations of the effects of extracts of Vernonia amygdalina, Carica papaya and Tapinanthus sessilifolius on digoxin transport and pharmacokinetics: assessing the significance on rat intestinal P-glycoprotein efflux.  

PubMed

Vernonia amygdalina (VA), Carica papaya (CP), and Tapinanthus sessilifolius (ML) are widely used in some countries as medicinal herbs to treat ailments including malaria, cancer, and diabetes. We previously reported the inhibitory effects of these herbs on permeability glycoprotein (P-gp) in Caco-2 cell monolayers. This study used ex vivo and in vivo models to investigate the likelihood of P-gp-mediated herb-drug interactions occurring. The study utilized excised rat intestinal tissues mounted in Ussing chambers to predict changes in drug absorption and an in vivo study in rats using digoxin as the P-gp substrate. Apparent permeability values and pharmacokinetic parameters of digoxin were compared to determine if co-administration of digoxin with ML, CP, or VA modulated the activity of P-gp. When VA was co-administered, the total area under the plasma concentration-time curve was significantly higher (2.1-fold) than when digoxin was administered alone. Co-administration of ML, VA, and CP significantly increased the mean digoxin apparent permeability in the mucosal-to-serosal direction by 7.8, 43.3, and 54.5%, respectively, in comparison to when digoxin was administered alone. These findings suggest that VA increases intestinal absorption of digoxin in vivo by inhibiting P-gp and may also modulate the pharmacokinetic disposition of other p-gp substrate drugs. PMID:23291634

Oga, Enoche Florence; Sekine, Shuichi; Horie, Toshiharu

2013-01-01

44

Chlorophyll fluorescence as a tool to evaluate the ripening of ‘Golden’ papaya fruit  

Microsoft Academic Search

Fruit classification based on one or more physical or physiological attributes is important to improve quality during storage and marketing. Our objectives were to evaluate changes in chlorophyll fluorescence of papaya fruit (Carica papaya L. cv. Golden) at different ripeness stages and during the ripening to determine if this non-destructive technique might assist the evaluation of fruit ripeness. Maximal (Fm),

Ilana Urbano Bron; Rafael Vasconcelos Ribeiro; Marisa Azzolini; Angelo Pedro Jacomino; Eduardo Caruso Machado

2004-01-01

45

Detection of three wound-induced proteins in papaya latex.  

PubMed

The effects of routine mechanical wounding for latex collection from unripe fruits of the tropical Carica papaya tree were investigated. For that purpose, the protein composition of three different latexes was analyzed. The first one, commercially available, was provided in the form of a spray-dried powder, the second one was harvested from fully grown but unripe papaya fruits that are regularly tapped for latex production and the last one, was obtained from similar fruits wounded for the first time. Repeated mechanical wounding was found to profoundly affect the protein content of the latex inducing, among others, activation of papain. Regularly tapped latexes also accumulated several low molecular weight proteins not yet identified, as well as three proteins identified as a trypsin inhibitor, a class-II chitinase and a glutaminyl cyclase on the basis of their enzymatic or inhibitory activities and chromatographic elution profiles. This latter was found here, for the first time, to be a wound-induced protein. The roles of these proteins in the plant defense mechanism are discussed. PMID:15003415

Azarkan, Mohamed; Wintjens, René; Looze, Yvan; Baeyens-Volant, Danielle

2004-03-01

46

Development of Transgenic Papaya through Agrobacterium-Mediated Transformation.  

PubMed

Transgenic papaya plants were regenerated from hypocotyls and immature zygotic embryo after cocultivation with Agrobacterium tumefaciens LBA-4404 carrying a binary plasmid vector system containing neomycin phosphotransferase (nptII) gene as the selectable marker and ?-glucuronidase (GUS) as the reporter gene. The explants were co-cultivated with Agrobacterium tumefaciens on regeneration medium containing 500?mg/L carbenicillin?+?200?mg/L cefotaxime for one week. The cocultivated explants were transferred into the final selection medium containing 500?mg/L carbenicillin?+?200?mg/L cefotaxime?+?50?mg/L kanamycin for callus induction as well as plant regeneration. The callus derived from the hypocotyls of Carica papaya cv. Shahi showed the highest positive GUS activities compared to Carica papaya cv. Ranchi. The transformed callus grew vigorously and formed embryos followed by transgenic plantlets successfully. The result of this study showed that the hypocotyls of C. papaya cv. Shahi and C. papaya cv. Ranchi are better explants for genetic transformation compared to immature embryos. The transformed C. papaya cv. Shahi also showed the maximum number of plant regeneration compared to that of C. papaya cv. Ranchi. PMID:24066284

Azad, Md Abul Kalam; Rabbani, Md Golam; Amin, Latifah; Sidik, Nik Marzuki

2013-01-01

47

Development of Transgenic Papaya through Agrobacterium-Mediated Transformation  

PubMed Central

Transgenic papaya plants were regenerated from hypocotyls and immature zygotic embryo after cocultivation with Agrobacterium tumefaciens LBA-4404 carrying a binary plasmid vector system containing neomycin phosphotransferase (nptII) gene as the selectable marker and ?-glucuronidase (GUS) as the reporter gene. The explants were co-cultivated with Agrobacterium tumefaciens on regeneration medium containing 500?mg/L carbenicillin?+?200?mg/L cefotaxime for one week. The cocultivated explants were transferred into the final selection medium containing 500?mg/L carbenicillin?+?200?mg/L cefotaxime?+?50?mg/L kanamycin for callus induction as well as plant regeneration. The callus derived from the hypocotyls of Carica papaya cv. Shahi showed the highest positive GUS activities compared to Carica papaya cv. Ranchi. The transformed callus grew vigorously and formed embryos followed by transgenic plantlets successfully. The result of this study showed that the hypocotyls of C. papaya cv. Shahi and C. papaya cv. Ranchi are better explants for genetic transformation compared to immature embryos. The transformed C. papaya cv. Shahi also showed the maximum number of plant regeneration compared to that of C. papaya cv. Ranchi. PMID:24066284

Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah; Sidik, Nik Marzuki

2013-01-01

48

P-type H +-ATPases activity, membrane integrity, and apoplastic pH during papaya fruit ripening  

Microsoft Academic Search

The P-type H+-ATPase activity and related apoplastic pH were analysed in papaya fruit (Carica papaya L. cv. Golden) at different stages of maturation. Postharvest ripening of papaya was characterized by ethylene emission, skin colouration, firmness, and titratable acidity (TA). The climacteric peak of ethylene production occurred on the 2nd day after harvest, along with a sharp decrease in ATP hydrolysis

Inga G. Azevedo; Jurandi G. Oliveira; Marcelo G. da Silva; Talita Pereira; Savio F. Corrêa; Helion Vargas; Arnoldo R. Façanha

2008-01-01

49

Structural characterization of two papaya chitinases, a family GH19 of glycosyl hydrolases.  

PubMed

Two chitinases, able to use tetra-N-acetylglucosamine, chitin and chitosan as substrates, were characterized after purification from Carica papaya latex. The complete amino acid sequence of the major form and about 40% of the minor one were determined through proteolytic digestions and mass spectroscopy analysis. Sequencing demonstrated that both papaya chitinases are members of the family 19 of glycosyl hydrolases (GH19). Based on the known 3-D structures of other members of family GH19, it was expected that papaya chitinases would adopt all-alpha structures. However, circular dichroism and infrared spectroscopy indicated, for the papaya chitinases, a content of 15-20% of extended structures besides the expected 40% of alpha helices. Since the fully sequenced papaya chitinase contains a large number of proline residues the possibility that papaya chitinase contains polyproline II stretches was examined in the context of their resistance against proteolytic degradation. PMID:17115118

Huet, J; Wyckmans, J; Wintjens, R; Boussard, P; Raussens, V; Vandenbussche, G; Ruysschaert, J M; Azarkan, M; Looze, Y

2006-12-01

50

New approach for papaya latex storage without virus degradation  

PubMed Central

Papaya meleira virus (PMeV) is the causal agent of papaya (Carica papaya L.) sticky disease, which has been detected through analysis of its double-stranded RNA (dsRNA) genome from plant latex. In this work we demonstrate that PMeV dsRNA is protected during 25 days when latex is diluted in citrate buffer pH 5.0 (1:1 v/v) and maintained at -20ºC. At the same temperature, some protection was observed for pure latex or latex diluted in ultra-pure water. Conversely, the dsRNA was almost completely degraded after 25 days when maintained at 25ºC, indicating the need for freezing. The proper procedures to collect and store papaya latex described here will contribute to efficient and large scale use of molecular diagnosis of PMeV. PMID:24031329

Rodrigues, Silas P.; Andrade, Josemar S.; Ventura, Jose A.; Fernandes, Patricia M. B.

2009-01-01

51

Applicability of the chymopapain gene used as endogenous reference gene for transgenic huanong no. 1 papaya detection.  

PubMed

The virus-resistant papaya (Carica papaya L.), Huanong no. 1, was the genetically modified (GM) fruit approved for growing in China in 2006. To implement the labeling regulation of GM papaya and its derivates, the development of papaya endogenous reference gene is very necessary for GM papaya detection. Herein, we reported one papaya specific gene, Chymopapain (CHY), as one suitable endogenous reference gene, used for GM papaya identification. Thereafter, we established the conventional and real-time quantitative PCR assays of the CHY gene. In the CHY conventional PCR assay, the limit of detection (LOD) was 25 copies of haploid papaya genome. In the CHY real-time quantitative PCR assay, both the LOD and the limit of quantification (LOQ) were as low as 12.5 copies of haploid papaya genome. Furthermore, we revealed the construct-specific sequence of Chinese GM papaya Huanong no. 1 and developed its conventional and quantitative PCR systems employing the CHY gene as endogenous reference gene. This work is useful for papaya specific identification and GM papaya detection. PMID:19722561

Guo, Jinchao; Yang, Litao; Liu, Xin; Zhang, Haibo; Qian, Bingjun; Zhang, Dabing

2009-08-12

52

Analysis of Papaya Cell Wall-Related Genes during Fruit Ripening Indicates a Central Role of Polygalacturonases during Pulp Softening  

PubMed Central

Papaya (Carica papaya L.) is a climacteric fleshy fruit that undergoes dramatic changes during ripening, most noticeably a severe pulp softening. However, little is known regarding the genetics of the cell wall metabolism in papayas. The present work describes the identification and characterization of genes related to pulp softening. We used gene expression profiling to analyze the correlations and co-expression networks of cell wall-related genes, and the results suggest that papaya pulp softening is accomplished by the interactions of multiple glycoside hydrolases. The polygalacturonase cpPG1 appeared to play a central role in the network and was further studied. The transient expression of cpPG1 in papaya results in pulp softening and leaf necrosis in the absence of ethylene action and confirms its role in papaya fruit ripening. PMID:25162506

Fabi, Joao Paulo; Broetto, Sabrina Garcia; da Silva, Sarah Ligia Garcia Leme; Zhong, Silin; Lajolo, Franco Maria; do Nascimento, Joao Roberto Oliveira

2014-01-01

53

Removal of hazardous pharmaceutical dyes by adsorption onto papaya seeds.  

PubMed

Papaya (Carica papaya L.) seeds were used as adsorbent to remove toxic pharmaceutical dyes (tartrazine and amaranth) from aqueous solutions, in order to extend application range. The effects of pH, initial dye concentration, contact time and temperature were investigated. The kinetic data were evaluated by the pseudo first-order, pseudo second-order and Elovich models. The equilibrium was evaluated by the Langmuir, Freundlich and Temkin isotherm models. It was found that adsorption favored a pH of 2.5, temperature of 298 K and equilibrium was attained at 180-200 min. The adsorption kinetics followed the pseudo second-order model, and the equilibrium was well represented by the Langmuir model. The maximum adsorption capacities were 51.0 and 37.4 mg g(-1) for tartrazine and amaranth, respectively. These results revealed that papaya seeds can be used as an alternative adsorbent to remove pharmaceutical dyes from aqueous solutions. PMID:25026586

Weber, Caroline Trevisan; Collazzo, Gabriela Carvalho; Mazutti, Marcio Antonio; Foletto, Edson Luiz; Dotto, Guilherme Luiz

2014-01-01

54

Phylogenetic positions of phytoplasmas associated with dieback, yellow crinkle and mosaic diseases of papaya, and their proposed inclusion in 'Candidatus Phytoplasma australiense' and a new taxon, 'Candidatus Phytoplasma australasia'.  

PubMed

DNA extracted from three papaya (Carica papaya L.) plants, individually affected by dieback, yellow crinkle or mosaic diseases, was subjected to PCR using phytoplasma-specific primers to amplify the 16S rRNA gene plus 16S-23S rRNA intergenic spacer region. Near-complete DNA sequences obtained for the three PCR amplimers were subjected to phylogenetic analyses and direct sequence comparison with other phytoplasma 16S rDNA and 16S-23S spacer region DNA sequences. The papaya yellow crinkle (PpYC) and papaya mosaic (PpM) sequences were identical to each other, but distinctly different from the papaya dieback (PpDB) sequence, showing 90.3% identity in the he 16S rDNA and 87.8% identity in the 16S-23S spacer region DNA sequences. A phylogenetic tree based on 16S rDNA sequences was calculated, in which PpYC and PpM are most closely related to the tomato big bud phytoplasma (TBB; 99.7% 16S rDNA sequence identity) from Australia, within subclade iii. This subclade consists of strains only reported occurring in the Southern Asian region and Australia, which indicates an Asian/Australasian origin. PpDB is most closely related to the Phormium yellow leaf phytoplasma from new Zealand (PYL; 99.9% identity) and the Australian grapevine yellows phytoplasma (AGY; 99.7% identity). These three phytoplasma strains form a distinct clade within subclade xii, which also includes the European strains STOL and VK as another distinct clade. The origin of the closely related but geographically separated AGY-like strains and STOL-like strains of subclade xii is unclear. It is proposed that phytoplasma strains PpDB, PYL and AGY be included in the previously described taxon 'Candidatus Phytoplasma australiense', and that PbYC, PpM and TBB be assigned to a new taxon, "Candidatus Phytoplasma australasia'. PMID:9734050

White, D T; Blackall, L L; Scott, P T; Walsh, K B

1998-07-01

55

Update on the development of virus-resistant papaya: virus-resistant transgenic papaya for people in rural communities of Thailand.  

PubMed

Papaya (Carica papaya L.) is one of the most important and preferred crops in rural communities in Thailand. Papaya ringspot virus (PRSV) is a serious disease of papaya throughout Thailand. Efforts to control the virus by various methods either have not been successful or have not resulted in sustainable control. In 1995, collaborative research by the Department of Agriculture of Thailand and Cornell University to develop transgenic papaya resistant to PRSV was initiated. Two local Thai cultivars were transformed by microprojectile bombardment with the use of a nontranslatable coat protein gene of PRSV from Khon Kaen. Numerous kanamycin-resistantplants were regenerated and were inoculated with the PRSV Khon Kaen isolate for selection of resistant lines. Since 1997, promising RO transgenic lines have been transferred to the research station at Thapra for subsequent screenhouse tests and selection of the most PRSV-resistant lines. In selection set 1, three R3 lines initially derived from Khaknuan papaya showed excellent resistance to PRSV (97% to 100%) and had a yield of fruit 70 times higher than nontransgenic Khaknuan papaya. In selection set 2, one R3 line initially derived from Khakdam papaya showed 100% resistance. Safety assessments of these transgenic papayas have so far found no impact on the surrounding ecology. No natural crossing between transgenic and nonmodified papaya was observed beyond a distance of 10 m from the test plots. Analysis of the nutritional composition found no differences in nutrient levels in comparison with the nonmodified counterparts. Molecular characterization by Southern blotting revealed three copies of the transgene presented; however, no coat protein product was expressed. Data on additional topics, such as the effects offeeding the transgenic papaya to rats and the stability of the gene inserts, are currently being gathered. PMID:16465990

Sakuanrungsirikul, S; Sarindu, N; Prasartsee, V; Chaikiatiyos, S; Siriyan, R; Sriwatanakul, M; Lekananon, P; Kitprasert, C; Boonsong, P; Kosiyachinda, P; Fermin, G; Gonsalves, D

2005-12-01

56

Effect of packaging materials and storage environment on postharvest quality of papaya fruit.  

PubMed

This experiment was conducted to assess the effects of packaging materials and storage environments on shelf life of papaya fruit (Carica papaya L.). A factorial combination of five packaging materials and two storage environments using randomized complete block design with three replications were used. The papaya fruits were evaluated for weight loss, percentage marketability, firmness, total soluble solids, pH, titratable acidity, ascorbic acid, reducing sugar and total sugar content. The packaged and cooled fruits remained firmer than unpackaged and evaporatively cooled fruits. Higher chemical compositions were recorded in the control fruits stored under ambient conditions during the earlier times of storage. Packaging and cooling maintained the chemical quality of papaya fruits better than the control sample fruits towards the end of storage periods. The evaporatively cooled storage combined with packaging improved the shelf life of papaya fruits by more than two fold. The polyethylene bag packaging combined with evaporatively cooled storage maintained the superior quality of papaya fruit for a period of 21 days. This integrated agro-technology is recommended for postharvest loss reduction biotechnology in hot regions. PMID:24876636

Azene, Mulualem; Workneh, Tilahun Seyoum; Woldetsadik, Kebede

2014-06-01

57

Draft Genome Sequence of Erwinia mallotivora BT-MARDI, Causative Agent of Papaya Dieback Disease  

PubMed Central

Erwinia mallotivora was isolated from papaya trees infected with dieback disease, which were planted at the Malaysian Agricultural Research and Development Institute (MARDI), Malaysia. Here, we report a draft genome sequence of E. mallotivora BT-MARDI, which offers an important source of information for understanding pathogen and host interaction during papaya dieback development. PMID:24812220

Abu Bakar, N.; Rozano, L.; Badrun, R.; Mat Amin, N.; Mohd Raih, M. F.

2014-01-01

58

Characterization of the exogenous insert and development of event-specific PCR detection methods for genetically modified Huanong No. 1 papaya.  

PubMed

Genetically modified (GM) papaya (Carica papaya L.), Huanong No. 1, was approved for commercialization in Guangdong province, China in 2006, and the development of the Huanong No. 1 papaya detection method is necessary for implementing genetically modified organism (GMO) labeling regulations. In this study, we reported the characterization of the exogenous integration of GM Huanong No. 1 papaya by means of conventional polymerase chain reaction (PCR) and thermal asymmetric interlaced (TAIL)-PCR strategies. The results suggested that one intact copy of the initial construction was integrated in the papaya genome and which probably resulted in one deletion (38 bp in size) of the host genomic DNA. Also, one unintended insertion of a 92 bp truncated NptII fragment was observed at the 5' end of the exogenous insert. Furthermore, we revealed its 5' and 3' flanking sequences between the insert DNA and the papaya genomic DNA, and developed the event-specific qualitative and quantitative PCR assays for GM Huanong No. 1 papaya based on the 5' integration flanking sequence. The relative limit of detection (LOD) of the qualitative PCR assay was about 0.01% in 100 ng of total papaya genomic DNA, corresponding to about 25 copies of papaya haploid genome. In the quantitative PCR, the limits of detection and quantification (LOD and LOQ) were as low as 12.5 and 25 copies of papaya haploid genome, respectively. In practical sample quantification, the quantified biases between the test and true values of three samples ranged from 0.44% to 4.41%. Collectively, we proposed that all of these results are useful for the identification and quantification of Huanong No. 1 papaya and its derivates. PMID:19645503

Guo, Jinchao; Yang, Litao; Liu, Xin; Guan, Xiaoyan; Jiang, Lingxi; Zhang, Dabing

2009-08-26

59

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species  

PubMed Central

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah

2012-01-01

60

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species.  

PubMed

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F(1) plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Azad, Md Abul Kalam; Rabbani, Md Golam; Amin, Latifah

2012-01-01

61

Papaya glutamine cyclase, a plant enzyme highly resistant to proteolysis, adopts an all-beta conformation.  

PubMed

Glutamine cyclases catalyse the conversion of L-glutaminyl-peptides into 5-oxoprolyl-peptides with the concomitant liberation of ammonia. We report here biophysical characterisation of the glutamine cyclase present in the laticiferous cells of the plant Carica papaya. After purification to near homogeneity, this enzyme was subjected to limited proteolysis and found to exhibit a high resistance to degradation and nicking. The structural reasons for this property were examined using circular dichroism and infrared spectroscopies. By combining the analyses of the infrared and CD spectra of papaya glutamine cyclase, its susceptibility to proteolysis, and its hydrogen-deuterium exchange characteristics, we conclude that this protein contains extensive beta-sheet structure and is likely to have only short immobile loops connecting its beta-strands. PMID:9851712

Oberg, K A; Ruysschaert, J M; Azarkan, M; Smolders, N; Zerhouni, S; Wintjens, R; Amrani, A; Looze, Y

1998-11-15

62

Beverages of lemon juice and exotic noni and papaya with potential for anticholinergic effects.  

PubMed

Lemon (Citrus limon (L.) Burm. f.) juice beverages enriched either with noni (Morinda citrifolia L.) (LN) or papaya (Carica papaya L.) (LP), were characterized by HPLC-DAD-ESI/MS(n), the antioxidant capacity was evaluated by (DPPH), superoxide (O2(-)), hydroxyl radicals (OH) and hypochlorous acid (HOCl) assays, and their potential as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors was also assessed. The fruits are rich in a wide range of bioactive phenolics. Regarding DPPH, OH and HOCl assays, the LP displayed strong activity, and LN was the most active against O2(-). Concerning cholinesterases, LP was the most active, mainly due to lemon juice contribution. The effect on the cholinesterases was not as strong as in previous reports on purified extracts, but the bioactive-rich beverages offer the possibility of dietary coadjutants for daily consumption of health-promoting substances by adults with aging-related cognitive or physical disorders. PMID:25306312

Gironés-Vilaplana, Amadeo; Valentão, Patrícia; Andrade, Paula B; Ferreres, Federico; Moreno, Diego A; García-Viguera, Cristina

2015-03-01

63

Trees  

NSDL National Science Digital Library

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

64

Cloning of the papaya chromoplast-specific lycopene beta-cyclase, CpCYC-b, controlling fruit flesh color reveals conserved microsynteny and a recombination hot spot.  

PubMed

Carotenoid pigments in fruits are indicative of the ripening process and potential nutritional value. Papaya (Carica papaya) fruit flesh color is caused by the accumulation of lycopene or beta-carotenoids in chromoplasts. It is a distinct feature affecting nutritional composition, fruit quality, shelf life, and consumer preference. To uncover the molecular basis of papaya flesh color, we took map-based cloning and candidate gene approaches using integrated genetic and physical maps. A DNA marker tightly linked to flesh color colocalized on a contig of the physical map with a cDNA probe of the tomato (Solanum lycopersicum) chromoplast-specific lycopene beta-cyclase, CYC-b. Candidate gene sequences were obtained from amplified fragments and verified by sequencing two bacterial artificial chromosomes containing the two alleles. Sequence comparison revealed a 2-bp insertion in the coding region of the recessive red flesh allele resulting in a frame-shift mutation and a premature stop codon. A color complementation test in bacteria confirmed that the papaya CpCYC-b is the gene controlling fruit flesh color. Sequence analysis of wild and cultivated papaya accessions showed the presence of this frame-shift mutation in all red flesh accessions examined. Evaluation of DNA markers near CpCYC-b revealed a recombination hot spot, showing that CpCYC-b is located in a gene-rich region with a recombination rate at 3.7 kb per centimorgan, more than 100-fold higher than the genome average at 400 kb per centimorgan. Conserved microsynteny of the CpCYC-b region is indicated by colinearity of two to four genes between papaya, Arabidopsis (Arabidopsis thaliana), grape (Vitis vinifera), and tomato. Our results enhanced our understanding of papaya flesh color inheritance and generated new tools for papaya improvement. PMID:20181753

Blas, Andrea L; Ming, Ray; Liu, Zhiyong; Veatch, Olivia J; Paull, Robert E; Moore, Paul H; Yu, Qingyi

2010-04-01

65

Herbicide options for weed control in papaya  

Microsoft Academic Search

This paper reviews the literature on weeds and weed control in papaya. There is limited research on this topic, and nearly all of the research focuses on herbicides. Effective use of paraquat and glyphosate in papaya is dependent on avoidance of spray contact to green bark and foliage. Pre-emergence herbicide tolerance is dependent on papaya age, size and maturity, and

R. K. NISHIMOTO

1997-01-01

66

Effects of nitric oxide treatment on the cell wall softening related enzymes and several hormones of papaya fruit during storage.  

PubMed

Papaya fruits (Carica papaya L. cv 'Sui you 2') harvested with < 5% yellow surface at the blossom end were fumigated with 60 microL/L of nitric oxide for 3 h and then stored at 20 degrees C with 85% relative humility for 20 days. The effects of nitric oxide treatment on ethylene production rate, the activities of cell wall softening related enzymes including polygalacturonase, pectin methyl esterase, pectate lyase and cellulase and the levels of hormones including indole acetic acid, abscisic acid, gibberellin and zeatin riboside were examined. The results showed that papaya fruits treated with nitric oxide had a significantly lower rate of ethylene production and a lesser loss of firmness during storage. A decrease in polygalacturonase, pectin methyl esterase, pectate lyase and cellulase activities was observed in nitric oxide treated fruit. In addition, the contents of indole acetic acid, abscisic acid and zeatin riboside were reduced in nitric oxide treated fruit, but no significant reduction in the level of gibberellin was found. These results indicate that nitric oxide treatment can effectively delay the softening and ripening of papaya fruit, likely via the regulation of cell wall softening related enzymes and certain hormones. PMID:23744122

Guo, Qin; Wu, Bin; Chen, Weixin; Zhang, Yuli; Wang, Jide; Li, Xueping

2014-06-01

67

Extraction of Antifungal Substances from Burkholderia cepacia with Antibiotic Activity against Colletotrichum gloeosporioides on Papaya (Carica papaya)  

Microsoft Academic Search

An experiment was conducted to extract and determine the nature of antifungal substances produced by Burkholderia cepacia strain B23 that were inhibitory towards Colletotrichum gloeosporioides. In addition, the effect of different culture media on the production of antifungal substances by B. cepacia B23 was also investigated to have improved efficacy of this biocontrol agent. B. cepacia B23 grew faster in

J. KADIR; M. A. RAHMAN; T. M. M. MAHMUD; R. ABDUL RAHMAN; M. M. BEGUM

68

Papaya extract to treat dengue: a novel therapeutic option?  

PubMed

Dengue is a viral disease that today affects a vast number of people in over 125 countries and is responsible for a sizable number of deaths. In the absence of an effective antiviral drug to treat the disease, various treatments are being investigated. Studies have indicated that the juice of the leaves of the Carica papaya plant from the family Caricaceae could help to increase the platelet levels in these patients. This review describes some of the published studies on this topic. The search was done independently by the two authors using PubMed, Google and the library database and included relevant articles of the last 10 years. A total of 7 studies were included in this review, which were one animal study, one case report, three case series and two randomized controlled trials. Although many of the studies and case reports published in literature lack adequate information, some of the studies do raise the possibility that this treatment could be an important option in the future. Further large-scale studies could establish the usefulness or ineffectiveness of this natural product in the treatment of dengue. PMID:24971201

Sarala, N; Paknikar, Ss

2014-05-01

69

Thermophysical Properties of Papaya Puree  

Microsoft Academic Search

The effects of soluble solids content and temperature on thermal properties of papaya puree were studied. Density and specific heat were measured using pycnometer and differential scanning calorimeter (DSC), respectively while thermal conductivity was measured using line heat source probe. Thermal diffusivity was then calculated from the experimental results of the specific heat, thermal conductivity and density. Thermal properties of

Ampawan Tansakul; Hataichanok Kantrong; Rattapon Saengrayup; Panthila Sura

2011-01-01

70

Thermophysical Properties of Papaya Puree  

Microsoft Academic Search

The effects of soluble solids content and temperature on thermal properties of papaya puree were studied. Density and specific heat were measured using a pycnometer and differential scanning calorimeter, respectively, while thermal conductivity was measured using a line heat source probe. Thermal diffusivity was then calculated from the experimental results of the specific heat, thermal conductivity, and density. Thermal properties

Ampawan Tansakul; Hataichanok Kantrong; Rattapon Saengrayup; Panthila Sura

2012-01-01

71

Cloning of the Papaya Chromoplast-Specific Lycopene ?-Cyclase, CpCYC-b, Controlling Fruit Flesh Color Reveals Conserved Microsynteny and a Recombination Hot Spot1[W][OA  

PubMed Central

Carotenoid pigments in fruits are indicative of the ripening process and potential nutritional value. Papaya (Carica papaya) fruit flesh color is caused by the accumulation of lycopene or ?-carotenoids in chromoplasts. It is a distinct feature affecting nutritional composition, fruit quality, shelf life, and consumer preference. To uncover the molecular basis of papaya flesh color, we took map-based cloning and candidate gene approaches using integrated genetic and physical maps. A DNA marker tightly linked to flesh color colocalized on a contig of the physical map with a cDNA probe of the tomato (Solanum lycopersicum) chromoplast-specific lycopene ?-cyclase, CYC-b. Candidate gene sequences were obtained from amplified fragments and verified by sequencing two bacterial artificial chromosomes containing the two alleles. Sequence comparison revealed a 2-bp insertion in the coding region of the recessive red flesh allele resulting in a frame-shift mutation and a premature stop codon. A color complementation test in bacteria confirmed that the papaya CpCYC-b is the gene controlling fruit flesh color. Sequence analysis of wild and cultivated papaya accessions showed the presence of this frame-shift mutation in all red flesh accessions examined. Evaluation of DNA markers near CpCYC-b revealed a recombination hot spot, showing that CpCYC-b is located in a gene-rich region with a recombination rate at 3.7 kb per centimorgan, more than 100-fold higher than the genome average at 400 kb per centimorgan. Conserved microsynteny of the CpCYC-b region is indicated by colinearity of two to four genes between papaya, Arabidopsis (Arabidopsis thaliana), grape (Vitis vinifera), and tomato. Our results enhanced our understanding of papaya flesh color inheritance and generated new tools for papaya improvement. PMID:20181753

Blas, Andrea L.; Ming, Ray; Liu, Zhiyong; Veatch, Olivia J.; Paull, Robert E.; Moore, Paul H.; Yu, Qingyi

2010-01-01

72

Cancer chemopreventive effects of the flavonoid-rich fraction isolated from papaya seeds.  

PubMed

Intervention to decelerate, arrest, or reverse the process of carcinogenesis by the use of either natural or synthetic agents individually or in combination has emerged as a promising and pragmatic medical approach to reduce cancer risk. In the present study, we examined the cancer chemopreventive potential of a flavonoid-rich fraction isolated from the seeds of Carica papaya, a plant traditionally referred to as papaw. The flavonoid-enriched benzene fraction of the aqueous extract exerted its anticancer properties in vitro through cytoprotection, antioxidative and antiinflammatory mechanisms and genoprotection in response to isocyanate-induced carcinogenicity. Medium-term anticarcinogenicity and 2-stage skin papillomagenesis studies conducted in benzopyrene-induced lung carcinogenesis and 7,12-dimethyl benz(a)anthracene-mediated skin papillomagenesis mouse models further validated our in vitro observations. This is the first demonstration of chemopreventive activities of papaya seed products, however, further studies to understand the subtle targets of intracellular signaling pathways, pharmacological profile and toxicological safety of this bioactive fraction are essential to pave the way for successful clinical translation. Our study supports the inverse association between dietary flavonoid intake and cancer risk. PMID:24820939

Pathak, Neelam; Khan, Saba; Bhargava, Arpit; Raghuram, Gorantla V; Jain, Deepika; Panwar, Hariom; Samarth, Ravindra M; Jain, Subodh K; Maudar, Kewal K; Mishra, Dinesh K; Mishra, Pradyumna K

2014-01-01

73

Effects of the Papaya meleira virus on papaya latex structure and composition  

Microsoft Academic Search

Spontaneous latex exudation is the main symptom of papaya sticky (meleira) disease caused by the Papaya meleira virus (PMeV), a double-stranded RNA (dsRNA) virus. This paper describes different effects of PMeV on papaya latex. Latex samples\\u000a were subjected to different histochemical tests to evaluate their chemical composition. Additionally, the integrity of the\\u000a latex particles was assessed by transmission and scanning

Silas P. Rodrigues; Maura Da Cunha; José A. Ventura; Patricia Machado Bueno Fernandes

2009-01-01

74

Trees, Trees, Trees!  

NSDL National Science Digital Library

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

1998-01-01

75

High-resolution structure of a papaya plant-defense barwin-like protein solved by in-house sulfur-SAD phasing.  

PubMed

The first crystal structure of a barwin-like protein, named carwin, has been determined at high resolution by single-wavelength anomalous diffraction (SAD) phasing using the six intrinsic S atoms present in the protein. The barwin-like protein was purified from Carica papaya latex and crystallized in the orthorhombic space group P212121. Using in-house Cu?K? X-ray radiation, 16 cumulative diffraction data sets were acquired to increase the signal-to-noise level and thereby the anomalous scattering signal. A sequence-database search on the papaya genome identified two carwin isoforms of 122 residues in length, both containing six S atoms that yield an estimated Bijvoet ratio of 0.93% at 1.54?Å wavelength. A systematic analysis of data quality and redundancy was performed to assess the capacity to locate the S atoms and to phase the data. It was observed that the crystal decay was low during data collection and that successful S-SAD phasing could be obtained with a relatively low data multiplicity of about 7. Using a synchrotron source, high-resolution data (1?Å) were collected from two different crystal forms of the papaya latex carwin. The refined structures showed a central ?-barrel of six strands surrounded by several ?-helices and loops. The ?-barrel of carwin appears to be a common structural module that is shared within several other unrelated proteins. Finally, the possible biological function of the protein is discussed. PMID:24100320

Huet, Joëlle; Teinkela Mbosso, Emmanuel Jean; Soror, Sameh; Meyer, Franck; Looze, Yvan; Wintjens, René; Wohlkönig, Alexandre

2013-10-01

76

Tocolytic and toxic activity of papaya seed extract on isolated rat uterus.  

PubMed

Carica papaya L. seeds extracted with 80% ethanol (EEPS) caused concentration-dependent tocolysis of uterine strips isolated from gravid and non-gravid rats. Prostaglandin F2alpha and oxytocin-induced contractions of the isolated rat uterus were also inhibited in a concentration-dependent fashion by EEPS. Recoveries of the uterine activity after EEPS-induced uterine quiescence were very weak. Higher concentration of EEPS caused prompt uterine quiescence, which was also significantly irreversible. Pre-incubation of the rat uterus in Ringer Locke solution containing 10 mg/ml of EEPS for 1 hour prior to suspension in tissue baths led to significant depression of the spontaneous and KCl (60 mM)-induced uterine contractions relative to the solvent control (P<0.05). Cross sections of EEPS-pretreated non-gravid rat uterus (stained with hematoxyline and eosin) examined under light microscope revealed degeneration of the endometrium and myometrium with obvious cytoplasmic vacuolation indicating that EEPS could have direct toxic effect on the uterine tissues. Previous workers have reported benzyl isothiocyanate (BITC) as the main bioactive and anthelmintic compound in different extracts of papaya seeds. Using electron impact ionization methods, the presence of BITC in EEPS was also shown in this study. Mass spectra of both EEPS and standard BITC showed a base peak of benzyl/tropylium ion at m/z 91 (indicative of an aromatic compound) and the molecular ion peak of BITC (m/z 149). Our earlier studies have demonstrated BITC-induced functional and morphological derangement of isolated uterus. We thus conclude that at high concentration, EEPS is capable of causing irreversible uterine tocolysis probably due to the damaging effect of BITC (its chief phytochemical) on the myometrium. PMID:14623029

Adebiyi, Adebowale; Ganesan Adaikan, P; Prasad, R N V

2003-12-19

77

Propagation Experiments with Avocado, Mango, and Papaya  

Microsoft Academic Search

During the past year several different investigations relative to the propagation of the avocado, mango and papaya have been conducted in Florida. In this preliminary report, the results of a few of the different experiments will be described. Germination media:—Avocado seeds of Gottfried (Mex.) during the summer season, and Shooter (Mex.) during the fall season; and Apple Mango seeds during

HAMILTON P. TRAUB; E. C. AUCHTER

78

[Detection of recombinant DNA from genetically modified papaya].  

PubMed

A method using polymerase chain reaction (PCR) was developed to detect the genetically modified (GM) papaya (55-1 line), of which the mandatory safety assessment has not been finished in Japan because of insufficient data. The papaya intrinsic papain gene was used as an internal control. The results of PCR amplification of the papain gene segment indicated that a commercial silica membrane type kit (QIAGEN DNeasy plant mini) was useful for extraction of DNA from papaya fruit, but not for extraction from canned papaya fruit. On the other hand, a commercial ion-exchange type kit (QIAGEN Genomic-tip) provided enough purified DNA for PCR from canned papaya fruit. Compared with the parental line and other commercial non-GM papayas, the DNA from GM papaya fruit provided specific amplification bands in PCR with five primer pairs (Nos. 2-6) including beta-glucuronidase and neomycin phosphotransferase II gene-specific ones. On the other hand, the primer pairs recognizing these genes showed false-positive results when we used DNAs from canned papaya. Therefore, we recommend that the primer pairs (Nos. 5 and 6) recognizing the sequences derived from two different species of organism should be used in order to detect specifically the GM papaya in canned fruits. PMID:11817137

Goda, Y; Asano, T; Shibuya, M; Hino, A; Toyoda, M

2001-08-01

79

Improved function of diabetic wound-site macrophages and accelerated wound closure in response to oral supplementation of a fermented papaya preparation.  

PubMed

Carica papaya Linn is widely known as a medicinal fruit. We sought to study a standardized fermented papaya preparation (FPP) for its effects on wound healing in adult obese diabetic (db/db) mice. FPP blunted the gain in blood glucose and improved the lipid profile after 8 weeks of oral supplementation. However, FPP did not influence weight gain during the supplementation period. FPP (0.2 g/kg body weight) supplementation for 8 weeks before wounding was effective in correcting wound closure. Studies on viable macrophages isolated from the wound site demonstrated that FPP supplementation improved respiratory-burst function as well as inducible NO production. Reactive oxygen species support numerous aspects of wound healing; NO availability in diabetic wounds is known to be compromised. Diabetic mice supplemented with FPP showed a higher abundance of CD68 as well as CD31 at the wound site, suggesting effective recruitment of monocytes and an improved proangiogenic response. This work provides the first evidence that diabetic-wound outcomes may benefit from FPP supplementation by specifically influencing the response of wound-site macrophages and the subsequent angiogenic response. Given that FPP has a long track record of safe human consumption, testing of the beneficial effects of FPP on diabetic wound-related outcomes in a clinical setting is warranted. PMID:20095880

Collard, Eric; Roy, Sashwati

2010-09-01

80

Improved Function of Diabetic Wound-Site Macrophages and Accelerated Wound Closure in Response to Oral Supplementation of a Fermented Papaya Preparation  

PubMed Central

Abstract Carica papaya Linn is widely known as a medicinal fruit. We sought to study a standardized fermented papaya preparation (FPP) for its effects on wound healing in adult obese diabetic (db/db) mice. FPP blunted the gain in blood glucose and improved the lipid profile after 8 weeks of oral supplementation. However, FPP did not influence weight gain during the supplementation period. FPP (0.2?g/kg body weight) supplementation for 8 weeks before wounding was effective in correcting wound closure. Studies on viable macrophages isolated from the wound site demonstrated that FPP supplementation improved respiratory-burst function as well as inducible NO production. Reactive oxygen species support numerous aspects of wound healing; NO availability in diabetic wounds is known to be compromised. Diabetic mice supplemented with FPP showed a higher abundance of CD68 as well as CD31 at the wound site, suggesting effective recruitment of monocytes and an improved proangiogenic response. This work provides the first evidence that diabetic-wound outcomes may benefit from FPP supplementation by specifically influencing the response of wound-site macrophages and the subsequent angiogenic response. Given that FPP has a long track record of safe human consumption, testing of the beneficial effects of FPP on diabetic wound–related outcomes in a clinical setting is warranted. Antioxid. Redox Signal. 13, 599–606. PMID:20095880

Collard, Eric

2010-01-01

81

Ficus carica L. (Moraceae): Phytochemistry, Traditional Uses and Biological Activities  

PubMed Central

This paper describes the botanical features of Ficus carica L. (Moraceae), its wide variety of chemical constituents, its use in traditional medicine as remedies for many health problems, and its biological activities. The plant has been used traditionally to treat various ailments such as gastric problems, inflammation, and cancer. Phytochemical studies on the leaves and fruits of the plant have shown that they are rich in phenolics, organic acids, and volatile compounds. However, there is little information on the phytochemicals present in the stem and root. Reports on the biological activities of the plant are mainly on its crude extracts which have been proven to possess many biological activities. Some of the most interesting therapeutic effects include anticancer, hepatoprotective, hypoglycemic, hypolipidemic, and antimicrobial activities. Thus, studies related to identification of the bioactive compounds and correlating them to their biological activities are very useful for further research to explore the potential of F. carica as a source of therapeutic agents. PMID:24159359

Mawa, Shukranul; Husain, Khairana; Jantan, Ibrahim

2013-01-01

82

77 FR 31294 - Notice of Request for Extension of Approval of an Information Collection; Importation of Papaya...  

Federal Register 2010, 2011, 2012, 2013

...Collection; Importation of Papaya From Colombia and Ecuador AGENCY: Animal and Plant...commercial shipments of fresh papaya from Colombia and Ecuador into the continental United...commercial shipments of fresh papaya from Colombia and Ecuador, contact Ms. Dorothy...

2012-05-25

83

7 CFR 319.56-25 - Papayas from Central America and Brazil.  

Code of Federal Regulations, 2010 CFR

...false Papayas from Central America and Brazil. 319.56-25 Section 319.56-25...56-25 Papayas from Central America and Brazil. The Solo type of papaya may be...one of the following locations: (1) Brazil: State of Espirito...

2010-01-01

84

Odour-active compounds in papaya fruit cv. Red Maradol.  

PubMed

Application of solid-phase microextraction and simultaneous distillation-extraction combined with GC-FID, GC-MS, aroma extract dilution analysis, and odour activity value were used to analyse volatile compounds from papaya fruit cv. Red Maradol and to estimate the most odour-active compounds. The analyses led to the identification of 137 compounds; 118 of them were positively identified. Twenty-five odorants were considered as odour-active compounds and contribute to the typical papaya aroma, from which ethyl butanoate, benzyl isothiocyanate, 1-hexen-3-one, (E)-?-ionone, and methyl benzoate were the most odour-active compounds. PMID:24176322

Pino, Jorge A

2014-03-01

85

Identification of Phenylpropanoids in Fig (Ficus carica L.) Leaves.  

PubMed

In this study, the phenylpropanoid composition and antioxidant activity of identified components in fig (Ficus carica L.) leaves were examined. Known polyphenols rutin, isoschaftoside, isoquercetin, and chlorogenic acid were identified. Furthermore, caffeoylmalic acid (CMA) was the most abundant polyphenol and was identified for the first time. CMA exhibited antioxidant activity similar to that of vitamin C or catechin. Psoralen and bergapten were identified as known furanocoumarins, with psoralen being the most abundant. Moreover, psoralic acid glucoside (PAG) was identified for the first time. As a precursor of psoralen, PAG content was equivalent to the psoralen content in moles. Notably, the content of these compounds varied between the five fig varieties, and the furanocoumarin and PAG contents varied more than that of the polyphenols. Further investigations concerning the influence of CMA and PAG on human health are necessary to elucidate functionalities of fig leaves. PMID:25198243

Takahashi, Toru; Okiura, Aya; Saito, Keita; Kohno, Masahiro

2014-10-15

86

First report of anaphylactic reaction after fig (Ficus carica) ingestion.  

PubMed

We report an anaphylactic reaction which occurred very shortly after ingestion of a fresh fig. The IgE-dependent mechanism was demonstrated on the basis of positivity of the prick test performed with fresh fig (Ficus carica) extract. In addition, we were able to detect specific IgE to the same extract in the serum. The patient did not demonstrate sensitization to other common allergens involved in respiratory and food allergies. However, detection of specific IgE to F. benjamina indicated a sensitization to weeping fig. The CAP F. benjamina was partially inhibited by preincubation of the serum with fig extract, suggesting that these two species of Ficus share some common allergens. In this context, the assumption can be made that weeping fig was responsible for the initial sensitization in this patient. PMID:7573846

Dechamp, C; Bessot, J C; Pauli, G; Deviller, P

1995-06-01

87

Crystal structure of papaya glutaminyl cyclase, an archetype for plant and bacterial glutaminyl cyclases.  

PubMed

Glutaminyl cyclases (QCs) (EC 2.3.2.5) catalyze the intramolecular cyclization of protein N-terminal glutamine residues into pyroglutamic acid with the concomitant liberation of ammonia. QCs may be classified in two groups containing, respectively, the mammalian enzymes, and the enzymes from plants, bacteria, and parasites. The crystal structure of the QC from the latex of Carica papaya (PQC) has been determined at 1.7A resolution. The structure was solved by the single wavelength anomalous diffraction technique using sulfur and zinc as anomalous scatterers. The enzyme folds into a five-bladed beta-propeller, with two additional alpha-helices and one beta hairpin. The propeller closure is achieved via an original molecular velcro, which links the last two blades into a large eight stranded beta-sheet. The zinc ion present in the PQC is bound via an octahedral coordination into an elongated cavity located along the pseudo 5-fold axis of the beta-propeller fold. This zinc ion presumably plays a structural role and may contribute to the exceptional stability of PQC, along with an extended hydrophobic packing, the absence of long loops, the three-joint molecular velcro and the overall folding itself. Multiple sequence alignments combined with structural analyses have allowed us to tentatively locate the active site, which is filled in the crystal structure either by a Tris molecule or an acetate ion. These analyses are further supported by the experimental evidence that Tris is a competitive inhibitor of PQC. The active site is located at the C-terminal entrance of the PQC central tunnel. W83, W110, W169, Q24, E69, N155, K225, F22 and F67 are highly conserved residues in the C-terminal entrance, and their putative role in catalysis is discussed. The PQC structure is representative of the plants, bacterial and parasite enzymes and contrasts with that of mammalian enzymes, that may possibly share a conserved scaffold of the bacterial aminopeptidase. PMID:16438985

Wintjens, René; Belrhali, Hassan; Clantin, Bernard; Azarkan, Mohamed; Bompard, Coralie; Baeyens-Volant, Danielle; Looze, Yvan; Villeret, Vincent

2006-03-24

88

X-ray structure of papaya chitinase reveals the substrate binding mode of glycosyl hydrolase family 19 chitinases.  

PubMed

The crystal structure of a chitinase from Carica papaya has been solved by the molecular replacement method and is reported to a resolution of 1.5 A. This enzyme belongs to family 19 of the glycosyl hydrolases. Crystals have been obtained in the presence of N-acetyl- d-glucosamine (GlcNAc) in the crystallization solution and two well-defined GlcNAc molecules have been identified in the catalytic cleft of the enzyme, at subsites -2 and +1. These GlcNAc moieties bind to the protein via an extensive network of interactions which also involves many hydrogen bonds mediated by water molecules, underlying their role in the catalytic mechanism. A complex of the enzyme with a tetra-GlcNAc molecule has been elaborated, using the experimental interactions observed for the bound GlcNAc saccharides. This model allows to define four major substrate interacting regions in the enzyme, comprising residues located around the catalytic Glu67 (His66 and Thr69), the short segment E89-R90 containing the second catalytic residue Glu89, the region 120-124 (residues Ser120, Trp121, Tyr123, and Asn124), and the alpha-helical segment 198-202 (residues Ile198, Asn199, Gly201, and Leu202). Water molecules from the crystal structure were introduced during the modeling procedure, allowing to pinpoint several additional residues involved in ligand binding that were not previously reported in studies of poly-GlcNAc/family 19 chitinase complexes. This work underlines the role played by water-mediated hydrogen bonding in substrate binding as well as in the catalytic mechanism of the GH family 19 chitinases. Finally, a new sequence motif for family 19 chitinases has been identified between residues Tyr111 and Tyr125. PMID:18636748

Huet, Joëlle; Rucktooa, Prakash; Clantin, Bernard; Azarkan, Mohamed; Looze, Yvan; Villeret, Vincent; Wintjens, René

2008-08-12

89

Int. J. Plant Sci. 163(1):5165. 2002. 2002 by The University of Chicago. All rights reserved.  

E-print Network

of the four genera of Caricaceae, with two species of Moringa used as an outgroup. In the tree resulting from included Moringa oleifera Lam. and Carica papaya L. as representatives of their respective families that the magnitude of differences between Moringa species would, in other plant groups, be used to delineate family

Olson, Mark

90

Ficus carica L. (Moraceae): an ancient source of food and health.  

PubMed

Since early in the man history, common fig was appreciated as food and for its medicinal properties. This review explores some aspects about the importance of Ficus carica L., an amazing and ancient source of medicines and food. Topics regarding chemistry, biological activity, ethno-pharmacological uses, and its nutritional value are discussed, as well as the potential of the species as a source of new and different chemical scaffolds. Very important in the past, appreciated in our time and extremely promising in the future, F. carica represents an interesting example of healthy foods and bioproducts. PMID:24996314

Barolo, Melisa I; Ruiz Mostacero, Nathalie; López, Silvia N

2014-12-01

91

Increasing the shelf- life of papaya through vacuum packing  

Microsoft Academic Search

The main objective of this study was to increase the shelf life of fruits through vacuum packing. Papaya fruits were pretreated\\u000a with waxing, oil application, purafil packets, tissue paper wrapping given along with control and were packed in 150 gauge\\u000a thickness polyethylene film bags under vacuum and another set of these samples under without vacuum. The fruits were then\\u000a stored

Geetha Padmanaban; Kanchana Singaravelu; Susheela Thirumaran Annavi

92

Papaya latex enzymes capable of detoxification of gliadin  

Microsoft Academic Search

Assay of fractions obtained from ion exchange chromatography of papaya latex on CM Sephadex-C50, size exclusion chromatography\\u000a on Sephacryl S-300 and size exclusion HPLC have provided an insight into the relative contributions of the gluten-detoxifying\\u000a enzymes present. This outcome has been achieved by the use of the above chromatographic techniques, coupled with assays of\\u000a lysosomal activity, protease activity using benzylarginine

H. J. Cornell; W. Doherty; T. Stelmasiak

2010-01-01

93

The Adoption of genetically modified papaya in Hawaii and its implications for developing countries 1  

Microsoft Academic Search

As agricultural biotechnology becomes increasingly commercialised, numerous constraints limit adoption by developing-country producers. These include technology access, impacts on farmers' yields and profits, privatisation of research and intellectual property, biosafety regulatory frameworks, and trade-related market restrictions. This essay analyses development of the genetically modified papaya and its commercialisation in Hawaii as a response to a virulent plant disease, papaya ringspot

C. Gonsalves; D. R. Lee; D. Gonsalves

2007-01-01

94

Fruit-specific expression of papaya subtilase gene.  

PubMed

Subtilisin-like serine proteases (EC 3.4.21) consist of a widespread family of enzymes that is involved in various processes including in plants. The full-length cDNA (CpSUB1) and the corresponding genomic DNA for papaya subtilase have been obtained using rapid amplification of cDNA ends (RACEs) and PCR primer walking techniques, respectively. The cDNA clone contains an open reading frame of 2316bp encoding 772 amino acids with a calculated molecular mass of 82.6kDa and an isoelectric point (pI) of 8.97. The CpSUB1 gene is composed of nine exons and eight introns. The amino acid sequence encoded by CpSUB1 shared high identity (>60%) with the amino acid sequence of other plant subtilisin-like proteases. Sequence analysis of CpSUB1 revealed the presence of a possible signal peptide (25 amino acid residues) and an NH(2)-terminal prosequence (88 amino acid residues). In addition, papaya subtilase possesses the characteristic subtilisin catalytic triad amino acids namely Asp, His and Ser, together with the substrate-binding site, Asn. DNA hybridization analysis showed that subtilase gene exists as a single copy in the papaya genome. RNA hybridization analyses showed that expression of the subtilase transcripts was only detected in mesocarp but not in non-fruit tissues. Gene expression in fruit tissues reached the highest level during the ripening stage at which the fruits undergo dramatic softening process. Subsequently, pro-subtilase ( approximately 80kDa) was expressed as recombinant pro-enzyme ( approximately 97kDa), which was used to generate antiserum against papaya subtilase, anti-sub. Protein gel blot analysis using anti-sub towards total protein extracted from all ripening stages revealed that a protein with a molecular mass of approximately 70kDa reacted with the antiserum. Hence both RNA hybridization and protein gel blot analyses confirmed the presence of subtilase during papaya fruit ripening, pointing to its possible involvement in this important process. PMID:19729222

Othman, Roohaida; Nuraziyan, Azimi

2010-01-15

95

Central nervous system activity of an aqueous acetonic extract of Ficus carica L. in mice  

PubMed Central

Background: Ficus carica Linn. is reported to possess variety of activities, but its potential in CNS disorders is still to be explored. Objective: The present study was carried out to evaluate the CNS depressant activity of aqueous acetonic extract of Ficus carica Linn on different models in mice. Materials and Methods: The aerial parts of the plant Ficus carica L. were extracted with aqueous acetone and the solvent was removed by rotary vacuum evaporator under reduced pressure. A crude extract was given orally and its effects were tested on ketamine-induced sleeping time, muscle-coordination, anxiety (elevated-plus maze and Staircase test), convulsions [maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced seizures], and nociception. In addition, we determined the levels of neurotransmitters, norepinephrine (NE) and 5-hydroxytryptamine (5-HT). Results: Results from the experimental models tested showed: (1) a delay on onset and prolongation of sleep of ketamine-induced sleeping time; (2) significant muscle relaxant activity; (3) a significant attenuation in the anxiety-response (4) a delay in the onset of seizures and reduction in duration of seizures and mortality induced by MES and PTZ; (5) a reduction in the licking time in nociception test and (6) increased levels of NE and 5-HT. Conclusion: This suggests that Ficus carica L. exerts its CNS depressive effect by modulating the neurotransmitters NE and 5-HT in the brain. PMID:24948859

Bhanushali, Mittal M.; Makhija, Dinesh T.; Joshi, Yadunath M.

2014-01-01

96

Phospholipid Profile of the Stomach and Duodenum of Normal Rabbits Fed with Supplements of Unripe Pawpaw (Carica papaya) and Unripe Plantain (Musa sapientum) Extract  

NASA Astrophysics Data System (ADS)

This study reports the effect of unripe pawpaw and/or unripe plantain extracts on the phospholipid profile of the stomach and duodenum of normal rabbits. Supplementation of chow with unripe pawpaw or plantain extract significantly reduced (p< 0.05) the weight gained by rabbits compared with the control. The total phospholipids content in the stomach and duodenum were significantly increased (p< 0.05) in the test groups compared to the control. In the stomach and duodenum, phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin (SGM) were significantly increased (p< 0.05) in the test groups compared to the control. Pawpaw occasioned a decrease in the PE/PC ratio in both tissues as against an increase observed in the SGM/PC ratio. The results presented suggests that unripe pawpaw meal and unripe plantain extract alter the phospholipid profile of the stomach and duodenum in ways which may affect membrane fluidity of these tissues and would have profound effect on the gastro-duodenal mucosa and thus have implication(s) for gastric and duodenal ulcers in rabbits.

Eriyamremu, G. E.; Asagba, S. O.; Osagie, V. E.; Ojeaburu, S. I.; Lolodi, O.

97

Hepatoprotective Effect of Ficus carica Leaf Extract on Mice Intoxicated with Carbon Tetrachloride  

PubMed Central

Protective action of Ficus carica leaf ethanolic extract (obtained by maceration) was evaluated in an animal model of hepatotoxicity induced by carbon tetrachloride (CCl4). Male albino mice were divided into six groups. group I was normal control group; group II received olive oil (CCl4 solvent), groups III-VI received CCl4. After inducing hepatic damage, group III served as control for CCl4; and groups IV- VI received different doses of Ficus carica ethanol extract (200, 400 and 800 mg/kg) prior to intoxication with CCl4. Liver marker enzymes were assayed in serum. Sections of livers were observed under microscope for the histopathological changes. Levels of marker enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased significantly in CCl4 treated mice (group III). In groups IV, V and VI, pre-treated with the plant extract and intoxicated with CCl4, decreased activities of these two enzymes were observed. Also, pre-treatment with the extract in these groups resulted in less pronounced destruction of the liver architecture with no fibrosis and moderate inflammation was observed compared with group III. The present observations suggested that the treatment with Ficus carica leaf extract in dose of 200 mg/kg enhanced protection against CCl4 induced hepatic damage. PMID:24363682

Aghel, Nasrin; Kalantari, Heibatollah; Rezazadeh, Shohreh

2011-01-01

98

Removal and recovery of heavy metals from aqueous solution using papaya wood as a new biosorbent  

Microsoft Academic Search

Papaya wood was evaluated as a new biosorbent of heavy metals. On contacting 10mgl?l copper(II), cadmium(II) and zinc(II) solutions with 5gl?1 papaya wood, during shake flask contact time of 60min, the respective metal removal was noted to be 97.8, 94.9 and 66.8%. Sorption was most efficient at pH 5. Metal ion biosorption increased as the ratio of metal solution to

Asma Saeed; M. Waheed Akhter; Muhammed Iqbal

2005-01-01

99

Maple tree  

NSDL National Science Digital Library

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

Derek Ramsey (None;)

2006-09-23

100

Comparative effects of dietary administered transgenic and conventional papaya on selected intestinal parameters in rat models.  

PubMed

Transformation of agricultural crops with novel genes has significantly advanced disease-resistance breeding, including virus resistance through the expression of virus sequences. In this study, the effects of long-term, repeated exposure to transgenic papayas carrying the coat protein gene of Papaya ringspot virus and conventional non-transgenic papaya on the histology and selected biochemical parameters of the intestinal tract were compared. For 3 months, male and female Wistar rats received diets containing transgenic or non-transgenic papaya at twice the equivalent of the average daily consumption of fresh papayas. Gross and macroscopic appearance of intestinal tissues, as well as stomach tissues, was comparable (P < 0.05) as were total intestinal bacterial counts and activities of beta-glucuronidase. Activities of disaccharidases were not affected, neither were those of amylase (P < 0.05). Although significant differences were noted in the activity of Ca(2+) and Na(+)/K(+) ATPase brush border enzymes, no morphological alteration in the integrity of the intestinal mucosa was found. Overall, negligible effects on feed intake, body weight, and fecal output were observed (P < 0.05). Taken together, long-term exposure to diets formulated with transgenic papaya did not result in biologically important unintended effects. PMID:19690973

Powell, Melissa; Wheatley, Andrew O; Omoruyi, Felix; Asemota, Helen N; Williams, Nadia P; Tennant, Paula F

2010-06-01

101

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

102

SGI -Feature Story: Papaya Genome Sequencing Project Opens Vast Ar... http://www.sgi.com/company_info/features/2007/papaya.html 1 of 4 3/5/2008 12:31 PM  

E-print Network

. Genetically modifying the papaya to create a ringspot-resistant transgenic or "hermaphrodite" variety saved ­ to be sequenced, helping to pave the way for international export of genetically modified fruits and vegetables to study sex chromosome evolution and sex determination in a variety of organisms. Papaya offers several

Alam, Maqsudul

103

Influence of chromoplast morphology on carotenoid bioaccessibility of carrot, mango, papaya, and tomato.  

PubMed

Based on the observation of outstanding dissimilarities of the morphology of pigment-containing chromoplasts in nutritionally important carotenoid sources, the bioaccessibility (BA) of carotenoids from edible portions of carrot, mango, papaya, and tomato was compared using an in vitro digestion model. While carrot and tomato contained large carotenoid crystals clearly visible by light microscopy, mango and papaya contained different types of carotenoid-bearing structures. Particularly, ?-carotene is deposited in globular and tubular elements in papaya and mango chromoplasts, where carotenoids accumulate in a lipid-dissolved and liquid-crystalline form, respectively. The highest BA of ?-carotene was found for mango (10.1%), followed by papaya (5.3%), tomato (3.1%), and carrot (0.5%). In our digestion model, differences between total lycopene BA from papaya and tomato were insignificant, possibly since both pigments occur in a solid crystalline deposition form in both fruits. Furthermore, the BA of lutein, ?-cryptoxanthin, and ?-cryptoxanthin esters was shown to be superior to that of the carotenes from the respective food sources. The effect of lipid addition to the different food sources was studied. Although BA was enhanced for most carotenoids, the above-mentioned ranking of BAs of ?-carotene remained unchanged after lipid addition. Consequently, the physical form of carotenoid deposition in plant chromoplasts is suggested to have major impact on their liberation efficiency from the food matrices. PMID:22980866

Schweiggert, Ralf M; Mezger, Dominik; Schimpf, Franziska; Steingass, Christof B; Carle, Reinhold

2012-12-15

104

Hepatoprotective Activity of Ficus carica Leaf Extract on Rifampicin-Induced Hepatic Damage in Rats  

PubMed Central

Shade dried leaves of Ficus carica were extracted using petroleum ether (60-80°) and tested for antihepatotoxic activity on rats treated with 50 mg/kg of rifampicin orally. The parameters assessed were serum levels of glutamic oxaloacetate transaminase, glutamic pyruvic transaminase, bilirubin and histological changes in liver. Liver weights and pentobarbitione sleeping time as a functional parameter were also monitored. There was significant reversal of biochemical, histological and functional changes induced by rifampicin treatment in rats by petroleum ether extract treatment, indicating promising hepatoprotective activity. PMID:20046747

Gond, N. Y.; Khadabadi, S. S.

2008-01-01

105

Hepatoprotective Activity of Ficus carica Leaf Extract on Rifampicin-Induced Hepatic Damage in Rats.  

PubMed

Shade dried leaves of Ficus carica were extracted using petroleum ether (60-80 degrees ) and tested for antihepatotoxic activity on rats treated with 50 mg/kg of rifampicin orally. The parameters assessed were serum levels of glutamic oxaloacetate transaminase, glutamic pyruvic transaminase, bilirubin and histological changes in liver. Liver weights and pentobarbitione sleeping time as a functional parameter were also monitored. There was significant reversal of biochemical, histological and functional changes induced by rifampicin treatment in rats by petroleum ether extract treatment, indicating promising hepatoprotective activity. PMID:20046747

Gond, N Y; Khadabadi, S S

2008-01-01

106

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

107

Tree Talk  

NSDL National Science Digital Library

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

Rosen, S.

2010-01-01

108

Optimization of process parameters for foam-mat drying of papaya pulp.  

PubMed

Experiments were carried out to optimize the process parameters for production of papaya powder using foam-mat drying. Papaya pulp was foamed by incorporating methyl cellulose (0.25, 0.5, 0.75 and 1 %, w/w), glycerol-mono-stearate (1, 2, 3 and 4 %, w/w) and egg white (5, 10, 15 and 20 %, w/w) as foaming agents. The maximum stable foam formation was 72, 90 and 125% at 0.75 % methyl cellulose, 3 % glycerol-mono-stearate and 15 % egg white respectively with 9°Brix pulp and whipping time of 20 min. The foamed pulp was dried at air temperature of 60, 65 and 70 °C with foam thickness of 2, 4, 6, 8 and 10 mm in a batch type cabinet dryer. The drying time required for foamed papaya pulp was lower than non-foamed pulp at all selected temperatures. Biochemical analysis results showed a significant reduction in ascorbic acid, ?-carotene and total sugars in the foamed papaya dried product at higher foam thickness (6, 8 and 10 mm) and temperature (65 and 70 °C due to destruction at higher drying temperature and increasing time. There was no significant change in other biochemical constituents such as pH and acidity. The organoleptic and sensory evaluation of the quality attributes of papaya powder obtained from the pulp of 9°Brix added with 3 % glycerol-mono-stearate, whipped for 20 min and dried with a foam thickness of 4 mm at a temperature of 60 °C was found to be optimum to produce the foam-mat dried papaya powder. PMID:25328192

Kandasamy, Palani; Varadharaju, N; Kalemullah, S; Maladhi, D

2014-10-01

109

Effects of papaya seed extract and benzyl isothiocyanate on vascular contraction.  

PubMed

To investigate their potentially toxic effects on mammalian vascular smooth muscle, pentane extracts of papaya seeds and the chief active ingredient in the extracts, benzyl isothiocyanate (BITC), were tested for their effects on the contraction of strips of dog carotid artery. BITC and the papaya seed extract caused relaxation when added to tissue strips that had been pre-contracted with phenylephrine (PE). Incubation of the tissue with papaya seed extract or BITC caused inhibition of contraction when the strips were subsequently contracted with KCl or PE. This relaxation and inhibition of contraction did not appear to be endothelium-dependent, as endothelium-denuded rings showed the same degree of relaxation or inhibition of contraction in response to the preparations/drugs as those with the endothelium intact. The effects of both BITC and the extract were irreversible, i.e., the tissue did not recover to normal contractile ability after extensive washing. Exposure of the tissue to the papaya seed extract caused slower relaxation of the tissue, compared to controls, both after contraction with PE and subsequent addition of carbachol (CCh), and after contraction with KCl and then washing. Calcium imaging studies using cultured endothelial cells showed strong influxes of Ca2+ into the cells in response to addition of the papaya seed extract. We conclude that these extracts, when present in high concentration, are cytotoxic by increasing the membrane permeability to Ca2+, and that the vascular effects of papaya seed extracts are consistent with the notion that BITC is the chief bio-active ingredient. PMID:12052434

Wilson, Ruth K; Kwan, Tony K; Kwan, Chiu-Yin; Sorger, George J

2002-06-21

110

In vitro antiviral activity of Ficus carica latex against caprine herpesvirus-1.  

PubMed

The latex of Ficus carica Linn. (Moraceae) has been shown to possess antiviral properties against some human viruses. To determine the ability of F. carica latex (F-latex) to interfere with the infection of caprine herpesvirus-1 (CpHV-1) in vitro, F-latex was resuspended in culture media containing 1% ethanol and was tested for potential antiviral effects against CpHV-1. Titration of CpHV-1 in the presence or in the absence of F-latex was performed on monolayers of Madin Darby Bovine Kidney (MDBK) cells. Simultaneous addition of F-latex and CpHV-1 to monolayers of MDBK cells resulted in a significant reduction of CpHV-1 titres 3 days post-infection and this effect was comparable to that induced by acyclovir. The study suggests that the F-latex is able to interfere with the replication of CpHV-1 in vitro on MDBK cells and future studies will determine the mechanisms responsible for the observed antiviral activity. PMID:24853920

Camero, Michele; Marinaro, Mariarosaria; Lovero, Angela; Elia, Gabriella; Losurdo, Michele; Buonavoglia, Canio; Tempesta, Maria

2014-11-01

111

Semen study of papaya workers exposed to ethylene dibromide  

SciTech Connect

A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in the exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.

Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.; Clapp, D.; Turner, T.

1984-01-01

112

Factor Trees  

NSDL National Science Digital Library

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

Playground, Math

2009-07-29

113

Tree frog  

NSDL National Science Digital Library

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

Hans Hillewaert (None;)

2008-04-20

114

Factor Trees  

NSDL National Science Digital Library

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

2010-01-01

115

Carotenoids are more bioavailable from papaya than from tomato and carrot in humans: a randomised cross-over study  

PubMed Central

Carrot, tomato and papaya represent important dietary sources of ?-carotene and lycopene. The main objective of the present study was to compare the bioavailability of carotenoids from these food sources in healthy human subjects. A total of sixteen participants were recruited for a randomised cross-over study. Test meals containing raw carrots, tomatoes and papayas were adjusted to deliver an equal amount of ?-carotene and lycopene. For the evaluation of bioavailability, TAG-rich lipoprotein (TRL) fractions containing newly absorbed carotenoids were analysed over 9.5 h after test meal consumption. The bioavailability of ?-carotene from papayas was approximately three times higher than that from carrots and tomatoes, whereas differences in the bioavailability of ?-carotene from carrots and tomatoes were insignificant. Retinyl esters appeared in the TRL fractions at a significantly higher concentration after the consumption of the papaya test meal. Similarly, lycopene was approximately 2.6 times more bioavailable from papayas than from tomatoes. Furthermore, the bioavailability of ?-cryptoxanthin from papayas was shown to be 2.9 and 2.3 times higher than that of the other papaya carotenoids ?-carotene and lycopene, respectively. The morphology of chromoplasts and the physical deposition form of carotenoids were hypothesised to play a major role in the differences observed in the bioavailability of carotenoids from the foods investigated. Particularly, the liquid-crystalline deposition of ?-carotene and the storage of lycopene in very small crystalloids in papayas were found to be associated with their high bioavailability. In conclusion, papaya was shown to provide highly bioavailable ?-carotene, ?-cryptoxanthin and lycopene and may represent a readily available dietary source of provitamin A for reducing the incidence of vitamin A deficiencies in many subtropical and tropical developing countries. PMID:23931131

Schweiggert, Ralf M.; Kopec, Rachel E.; Villalobos-Gutierrez, Maria G.; Hogel, Josef; Quesada, Silvia; Esquivel, Patricia; Schwartz, Steven J.; Carle, Reinhold

2014-01-01

116

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.

117

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

118

Cell wall modification in 1-methylcyclopropene-treated post-climacteric fresh-cut and intact papaya fruit  

Microsoft Academic Search

Papaya is a climacteric fruit in which ripening is greatly regulated by ethylene often associated with stress responses such\\u000a as wounding. The changes in cell wall compositions in papaya fruit at an advanced stage of ripening under stress conditions\\u000a including chilling temperature of 5°C and wounding employed as fresh-cut and how these changes were affected by an ethylene\\u000a action inhibitor

Muharrem Ergun; Yasar Karakurt; Donald J. Huber

119

ISOLATION AND PUNRIFICATION OF PSORALEN AND BERGAPTEN FROM FICUS CARICA L LEAVES BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY.  

PubMed

High-speed countercurrent chromatography was successfully applied for the first time for the separation of psoralen and bergapten from Ficus carica L leaves. The crudeextract obtained by light petroleum (b.p.: 60°C-90°C) from the dried leaves of Ficus carica L. was separated with a two-phase solvent system of n-Hexane-ethyl acetate-methanol-water (1:1:1:1, v/v). Each peak fraction was analyzed by high-performance liquid chromatography. The method yielded 4.4 mg of psoralen at 99.1% purity and 2.1 mg of bergapten at 98.2% purity from 400 mg of the crude extract in a single run. The two compounds were identified by (1)H-NMR, (13)C-NMR and MS. PMID:20351802

Chunyan, Chi; Bo, Shi; Ping, Liang; Jingmei, Li; Ito, Yoichiro

2009-01-01

120

Shade trees  

Microsoft Academic Search

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

Robert L. Cook

1984-01-01

121

Contrasted genetic diversity and differentiation among Mediterranean populations of Ficus carica L.: A study using mtDNA RFLP  

Microsoft Academic Search

Patterns of mitochondrial DNA (mtDNA) variation revealed by RFLP were investigated for 63 individuals of the common fig, Ficus carica L., in 15 supposedly natural populations throughout the Mediterranean basin. Fifteen haplotypes were detected using one restriction enzyme (HindIII) and four probes (atpa, coxIII, nad3rpsl2 and rps12). Mitochondrial diversity within populations varied from monomorphic to entirely polymorphic and population differentiation

B. Khadari; C. Grout; S. Santoni; F. Kjellberg

2005-01-01

122

21 CFR 184.1585 - Papain.  

Code of Federal Regulations, 2011 CFR

...No. 9001-73-4) is a proteolytic enzyme derived from Carica papaya L. Crude latex containing the enzyme is collected from slashed unripe papaya...aqueous solution of latex. The resulting enzyme preparation may be used in a liquid...

2011-04-01

123

21 CFR 184.1585 - Papain.  

Code of Federal Regulations, 2010 CFR

...No. 9001-73-4) is a proteolytic enzyme derived from Carica papaya L. Crude latex containing the enzyme is collected from slashed unripe papaya...aqueous solution of latex. The resulting enzyme preparation may be used in a liquid...

2010-04-01

124

21 CFR 184.1585 - Papain.  

Code of Federal Regulations, 2012 CFR

...No. 9001-73-4) is a proteolytic enzyme derived from Carica papaya L. Crude latex containing the enzyme is collected from slashed unripe papaya...aqueous solution of latex. The resulting enzyme preparation may be used in a liquid...

2012-04-01

125

21 CFR 184.1585 - Papain.  

Code of Federal Regulations, 2013 CFR

...No. 9001-73-4) is a proteolytic enzyme derived from Carica papaya L. Crude latex containing the enzyme is collected from slashed unripe papaya...aqueous solution of latex. The resulting enzyme preparation may be used in a liquid...

2013-04-01

126

21 CFR 184.1585 - Papain.  

...No. 9001-73-4) is a proteolytic enzyme derived from Carica papaya L. Crude latex containing the enzyme is collected from slashed unripe papaya...aqueous solution of latex. The resulting enzyme preparation may be used in a liquid...

2014-04-01

127

Tree Torture  

NSDL National Science Digital Library

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

Science Update;

2002-06-10

128

Tree Link  

NSDL National Science Digital Library

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

129

Identification of Natural Rubber and Characterization of Rubber Biosynthetic Activity in Fig Tree1  

PubMed Central

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and 13C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent Km values of 2.8 and 228 ?m, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg2+ ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree. PMID:10889262

Kang, Hunseung; Kang, Min Young; Han, Kyung-Hwan

2000-01-01

130

Structural characterization of the papaya cysteine proteinases at low pH.  

PubMed

Current control of gastrointestinal nematodes relies primarily on the use of synthetic drugs and encounters serious problems of resistance. Oral administration of plant cysteine proteinases, known to be capable of damaging nematode cuticles, has recently been recommended to overcome these problems. This prompted us to examine if plant cysteine proteinases like the four papaya proteinases papain, caricain, chymopapain, and glycine endopeptidase that have been investigated here can survive acidic pH conditions and pepsin degradation. The four papaya proteinases have been found to undergo, at low pH, a conformational transition that instantaneously converts their native forms into molten globules that are quite unstable and rapidly degraded by pepsin. As shown by activity measurements, the denatured state of these proteinases which finally results from acid treatment is completely irreversible. It is concluded that cysteine proteinases from plant origin may require to be protected against both acid denaturation and proteolysis to be effective in the gut after oral administration. PMID:16434027

Huet, Joëlle; Looze, Yvan; Bartik, Kristin; Raussens, Vincent; Wintjens, René; Boussard, Paule

2006-03-10

131

Use of papaya seeds as a biosorbent of methylene blue from aqueous solution.  

PubMed

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2-12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin-Raduschkevich, Tempkin, Jovanovich, Redlich-Peterson, Sips, Toth and Radke-Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g(-1). Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model. PMID:23863440

Paz, Diego S; Baiotto, Alexandre; Schwaab, Marcio; Mazutti, Marcio A; Bassaco, Mariana M; Bertuol, Daniel A; Foletto, Edson L; Meili, Lucas

2013-01-01

132

Development and Validation of a Multiplex Reverse Transcription PCR Assay for Simultaneous Detection of Three Papaya Viruses  

PubMed Central

Papaya ringspot virus (PRSV), Papaya leaf distortion mosaic virus (PLDMV), and Papaya mosaic virus (PapMV) produce similar symptoms in papaya. Each threatens commercial production of papaya on Hainan Island, China. In this study, a multiplex reverse transcription PCR assay was developed to detect simultaneously these three viruses by screening combinations of mixed primer pairs and optimizing the multiplex RT-PCR reaction conditions. A mixture of three specific primer pairs was used to amplify three distinct fragments of 613 bp from the P3 gene of PRSV, 355 bp from the CP gene of PLDMV, and 205 bp from the CP gene of PapMV, demonstrating the assay’s specificity. The sensitivity of the multiplex RT-PCR was evaluated by showing plasmids containing each of the viral target genes with 1.44 × 103, 1.79 × 103, and 1.91 × 102 copies for the three viruses could be detected successfully. The multiplex RT-PCR was applied successfully for detection of three viruses from 341 field samples collected from 18 counties of Hainan Island, China. Rates of single infections were 186/341 (54.5%), 93/341 (27.3%), and 3/341 (0.9%), for PRSV, PLDMV, and PapMV, respectively; 59/341 (17.3%) of the samples were co-infected with PRSV and PLDMV, which is the first time being reported in Hainan Island. This multiplex RT-PCR assay is a simple, rapid, sensitive, and cost-effective method for detecting multiple viruses in papaya and can be used for routine molecular diagnosis and epidemiological studies in papaya. PMID:25337891

Tuo, Decai; Shen, Wentao; Yang, Yong; Yan, Pu; Li, Xiaoying; Zhou, Peng

2014-01-01

133

Development and validation of a multiplex reverse transcription PCR assay for simultaneous detection of three papaya viruses.  

PubMed

Papaya ringspot virus (PRSV), Papaya leaf distortion mosaic virus (PLDMV), and Papaya mosaic virus (PapMV) produce similar symptoms in papaya. Each threatens commercial production of papaya on Hainan Island, China. In this study, a multiplex reverse transcription PCR assay was developed to detect simultaneously these three viruses by screening combinations of mixed primer pairs and optimizing the multiplex RT-PCR reaction conditions. A mixture of three specific primer pairs was used to amplify three distinct fragments of 613 bp from the P3 gene of PRSV, 355 bp from the CP gene of PLDMV, and 205 bp from the CP gene of PapMV, demonstrating the assay's specificity. The sensitivity of the multiplex RT-PCR was evaluated by showing plasmids containing each of the viral target genes with 1.44 × 103, 1.79 × 103, and 1.91 × 102 copies for the three viruses could be detected successfully. The multiplex RT-PCR was applied successfully for detection of three viruses from 341 field samples collected from 18 counties of Hainan Island, China. Rates of single infections were 186/341 (54.5%), 93/341 (27.3%), and 3/341 (0.9%), for PRSV, PLDMV, and PapMV, respectively; 59/341 (17.3%) of the samples were co-infected with PRSV and PLDMV, which is the first time being reported in Hainan Island. This multiplex RT-PCR assay is a simple, rapid, sensitive, and cost-effective method for detecting multiple viruses in papaya and can be used for routine molecular diagnosis and epidemiological studies in papaya. PMID:25337891

Tuo, Decai; Shen, Wentao; Yang, Yong; Yan, Pu; Li, Xiaoying; Zhou, Peng

2014-01-01

134

Phenol induced by irradiation does not impair sensory quality of fenugreek and papaya  

NASA Astrophysics Data System (ADS)

The effect of radiation processing on the sensory quality of fenugreek and papaya exposed to doses in the range of 2.5-10 kGy and 100 Gy-2.5 kGy respectively was investigated. Despite an increase in the content of phenol in the volatile oil of these food products overall sensory quality of the irradiated and control samples was not significantly affected by radiation processing.

Chatterjee, Suchandra; Variyar, Prasad S.; Sharma, Arun

2013-11-01

135

Sequencing papaya X and Yh chromosomes reveals molecular basis of incipient sex chromosome evolution  

PubMed Central

Sex determination in papaya is controlled by a recently evolved XY chromosome pair, with two slightly different Y chromosomes controlling the development of males (Y) and hermaphrodites (Yh). To study the events of early sex chromosome evolution, we sequenced the hermaphrodite-specific region of the Yh chromosome (HSY) and its X counterpart, yielding an 8.1-megabase (Mb) HSY pseudomolecule, and a 3.5-Mb sequence for the corresponding X region. The HSY is larger than the X region, mostly due to retrotransposon insertions. The papaya HSY differs from the X region by two large-scale inversions, the first of which likely caused the recombination suppression between the X and Yh chromosomes, followed by numerous additional chromosomal rearrangements. Altogether, including the X and/or HSY regions, 124 transcription units were annotated, including 50 functional pairs present in both the X and HSY. Ten HSY genes had functional homologs elsewhere in the papaya autosomal regions, suggesting movement of genes onto the HSY, whereas the X region had none. Sequence divergence between 70 transcripts shared by the X and HSY revealed two evolutionary strata in the X chromosome, corresponding to the two inversions on the HSY, the older of which evolved about 7.0 million years ago. Gene content differences between the HSY and X are greatest in the older stratum, whereas the gene content and order of the collinear regions are identical. Our findings support theoretical models of early sex chromosome evolution. PMID:22869747

Wang, Jianping; Na, Jong-Kuk; Yu, Qingyi; Gschwend, Andrea R.; Han, Jennifer; Zeng, Fanchang; Aryal, Rishi; VanBuren, Robert; Murray, Jan E.; Zhang, Wenli; Navajas-Perez, Rafael; Feltus, F. Alex; Lemke, Cornelia; Tong, Eric J.; Chen, Cuixia; Man Wai, Ching; Singh, Ratnesh; Wang, Ming-Li; Min, Xiang Jia; Alam, Maqsudul; Charlesworth, Deborah; Moore, Paul H.; Jiang, Jiming; Paterson, Andrew H.; Ming, Ray

2012-01-01

136

Ephedra alte (Joint Pine): An Invasive, Problematic Weedy Species in Forestry and Fruit Tree Orchards in Jordan  

PubMed Central

A field survey was carried out to record plant species climbed by Ephedra alte in certain parts of Jordan during 2008–2010. Forty species of shrubs, ornamental, fruit, and forest trees belonging to 24 plant families suffered from the climbing habit of E. alte. Growth of host plants was adversely affected by E. alte growth that extended over their vegetation. In addition to its possible competition for water and nutrients, the extensive growth it forms over host species prevents photosynthesis, smothers growth and makes plants die underneath the extensive cover. However, E. alte did not climb all plant species, indicating a host preference range. Damaged fruit trees included Amygdalus communis, Citrus aurantifolia, Ficus carica, Olea europaea, Opuntia ficus-indica, and Punica granatum. Forestry species that were adversely affected included Acacia cyanophylla, Ceratonia siliqua, Crataegus azarolus, Cupressus sempervirens, Pinus halepensis, Pistacia atlantica, Pistacia palaestina, Quercus coccifera, Quercus infectoria, Retama raetam, Rhamnus palaestina, Rhus tripartita, and Zizyphus spina-christi. Woody ornamentals attacked were Ailanthus altissima, Hedera helix, Jasminum fruticans, Jasminum grandiflorum, Nerium oleander, and Pyracantha coccinea. Results indicated that E. alte is a strong competitive for light and can completely smother plants supporting its growth. A. communis, F. carica, R. palaestina, and C. azarolus were most frequently attacked. PMID:22645486

Qasem, Jamal R.

2012-01-01

137

Ephedra alte (joint pine): an invasive, problematic weedy species in forestry and fruit tree orchards in Jordan.  

PubMed

A field survey was carried out to record plant species climbed by Ephedra alte in certain parts of Jordan during 2008-2010. Forty species of shrubs, ornamental, fruit, and forest trees belonging to 24 plant families suffered from the climbing habit of E. alte. Growth of host plants was adversely affected by E. alte growth that extended over their vegetation. In addition to its possible competition for water and nutrients, the extensive growth it forms over host species prevents photosynthesis, smothers growth and makes plants die underneath the extensive cover. However, E. alte did not climb all plant species, indicating a host preference range. Damaged fruit trees included Amygdalus communis, Citrus aurantifolia, Ficus carica, Olea europaea, Opuntia ficus-indica, and Punica granatum. Forestry species that were adversely affected included Acacia cyanophylla, Ceratonia siliqua, Crataegus azarolus, Cupressus sempervirens, Pinus halepensis, Pistacia atlantica, Pistacia palaestina, Quercus coccifera, Quercus infectoria, Retama raetam, Rhamnus palaestina, Rhus tripartita, and Zizyphus spina-christi. Woody ornamentals attacked were Ailanthus altissima, Hedera helix, Jasminum fruticans, Jasminum grandiflorum, Nerium oleander, and Pyracantha coccinea. Results indicated that E. alte is a strong competitive for light and can completely smother plants supporting its growth. A. communis, F. carica, R. palaestina, and C. azarolus were most frequently attacked. PMID:22645486

Qasem, Jamal R

2012-01-01

138

Tree2 - Decision Trees for Tree Structured Data  

Microsoft Academic Search

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

Björn Bringmann; Albrecht Zimmermann

2005-01-01

139

DNA extraction method using a silica-base resin type kit for the detection of genetically modified papaya.  

PubMed

Genetically modified (GM) papaya has not yet been approved for importation into, or cultivation in the European Union (EU) and Japan. A DNA extraction method using the Qiagen DNeasy Plant Mini Kit (PM method) and a method using a buffer containing cetyltrimethyl ammonium bromide (CTAB method) have been adopted as the official Japanese methods for detecting GM foods. However, the amounts of DNA extracted from papaya by these methods are very low. Therefore, we investigated an extraction method to obtain a high yield of DNA from raw or freeze-dried fresh papaya using the Promega Wizard DNA Clean-Up Resin System (WCR). The incubation for the extraction was carried out at 58 degrees C without proteinase K for 15 min. The extract was applied to a mini-column, then the column was washed with 80% isopropyl alcohol, and genomic DNA adsorbed on the column was eluted with TE buffer. The WCR method gave a higher yield of genomic DNA, and was simpler and faster than the PM method or CTAB method. In addition, it could be used to extract genomic DNA from fresh papaya at various stages of ripeness. Based on these results, we propose that the present method using WCR is the most practical and useful way to extract genomic DNA for the purpose of detecting GM papaya. PMID:18503240

Ohmori, Kiyomi; Tsuchiya, Hisayo; Watanabe, Takahiro; Akiyama, Hiroshi; Maitani, Tamio; Yamada, Toshiharu; Hirayama, Kuni; Satoh, Shuji

2008-04-01

140

American Chestnut Tree  

NSDL National Science Digital Library

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

Ket

2008-09-02

141

Minnesota Tree Blitz  

NSDL National Science Digital Library

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

142

Detection of platypus-type L/D-peptide isomerase activity in aqueous extracts of papaya fruit.  

PubMed

Peptide isomerase catalyses the post-translational isomerisation of the L: - to the D: -form of an amino acid residue around the N/C-termini of substrate peptides. To date, some peptide isomerases have been found in a limited number of animal secretions and cells. We show here that papaya extracts have weak peptide isomerase activity. The activity was detected in each 30-100 kDa fraction of the flesh and the seed extracts of unripe and ripe papaya fruit. The definitive activity was confirmed in the ripe papaya extracts, but even then it was much less active than that of the other peptide isomerases previously reported. The activity was markedly inhibited by methanol, and partly so by amastatin and diethyl pyrocarbonate. This is the first report of peptide isomerase activity in a plant and suggests that perhaps every living organism may have some peptide isomerase activity. PMID:22648682

Arakawa, Kensuke; Koh, Jennifer M S; Crossett, Ben; Torres, Allan M; Kuchel, Philip W

2012-09-01

143

Trees and Air Quality  

NSDL National Science Digital Library

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

144

Tree Decline Shade trees often gradually lose  

E-print Network

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

145

Estimating species trees from unrooted gene trees.  

PubMed

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

Liu, Liang; Yu, Lili

2011-10-01

146

A tree-to-tree model for statistical machine translation  

E-print Network

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

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

2008-01-01

147

Protective Role of Ficus carica Stem Extract against Hepatic Oxidative Damage Induced by Methanol in Male Wistar Rats  

PubMed Central

The present study was aimed to investigate the antioxidant activity of Ficus carica stem extract (FE) in methanol-induced hepatotoxicity in male Wistar rats. The rats were divided into two batches: 16 control rats (C) drinking tap water and 16 treated rats drinking Ficus carica stem extract for six weeks. Then, each group was divided into two subgroups, and one of them was intraperitoneally injected (i.p.) daily methanol at a dose of 2.37?g/kg body weight i.p. for 30 days, for four weeks. The results showed that FE was found to contain large amounts of polyphenols and carotenoids. The treatment with methanol exhibited a significant increase of serum hepatic biochemical parameters (ALT, AST, ALP, and LDH) and hepatic lipid peroxidation. Hepatic antioxidant enzymes, namely, SOD, CAT, and GSH-Px, were significantly decreased in methanol-treated animals. FE treatment prior to methanol intoxication has significant role in protecting animals from methanol-induced hepatic oxidative damage. PMID:22203864

Saoudi, Mongi; El Feki, Abdelfattah

2012-01-01

148

Categorizing Ideas about Trees: A Tree of Trees  

PubMed Central

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

Fisler, Marie; Lecointre, Guillaume

2013-01-01

149

Evolution of Decision Trees  

Microsoft Academic Search

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

Xavier Llor; Josep M. Garrelly

150

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

151

Effect of Temperature on the Development and Survival of Immature Stages of the Carambola Fruit Fly, Bactrocera carambolae, and the Asian Papaya Fruit Fly, Bactrocera papayae, Reared On Guava Diet  

PubMed Central

Members of the Bactrocera dorsalis Hendel (Diptera: Tephritidae) complex constitute wellrecognized destructive pests of fruits in peninsular Thailand. The development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae Drew & Hancock, and the Asian papaya fruit fly, Bactrocera papayae Drew & Hancock, were compared at six constant temperatures of 15, 20, 25, 27, 30, and 35°C, 70 ± 5% relative humidity, and a photoperiod of 12:12 (L:D). The objectives were to determine the effect of temperature on the developmental stages for optimizing rearing and to understand the geographical pattern of occurrence of these fruit fly species. A strong and positive linear relationship was observed between temperature and developmental rate of immature stages of B. carambolae. Similarly, a strong and positive linear relationship was observed between temperature and developmental rate of B. papayae. A temperature summation model was used to estimate the lower threshold temperature and the thermal constant. Bactrocera papayae was significantly faster in development and higher in survival and appeared to be better adapted to low temperatures than B. carambolae, as it exhibited the lowest threshold temperatures at all immature stages. The observed differences in response to various temperatures revealed to some extent the impact of temperature on these species' distribution in peninsular Thailand and other parts of the world. PMID:25368070

Danjuma, Solomon; Thaochan, Narit; Permkam, Surakrai; Satasook, Chutamas

2014-01-01

152

Characterization of typo-, regio-, and stereo-selectivities of babaco latex lipase in aqueous and organic media.  

PubMed

The unripe fruit of babaco (Vasconcellea x heilbornii; syn. Carica pentagona) contains a latex, similar to that in Carica papaya, which exhibits lipolytic activity. Herein, the regioselectivity, stereoselectivity and typoselectivity in both hydrolysis and acyltransfer reactions of babaco latex lipases were studied and compared to those of Carica papaya latex. In hydrolysis, both biocatalysts are 1,3-regioselective with ratios for 1,2-2,3-diacylglycerols/1,3-diacylglycerol of 6.5 and 21 for babaco and papaya, respectively. In contrast, papaya latex had a slight sn-3 stereopreference. Babaco latex displayed a higher activity on triacylglycerols with short chain and unsaturated fatty acids. PMID:18038267

Cambon, E; Rodriguez, J A; Pina, M; Arondel, V; Carriere, F; Turon, F; Ruales, J; Villeneuve, P

2008-04-01

153

Effect of pre-harvest calcium chloride applications on fruit calcium level and post-harvest anthracnose disease of papaya  

E-print Network

deficiency could be reduced by calcium spraying (Kader, 2002). However, there are few re- ports about effectsEffect of pre-harvest calcium chloride applications on fruit calcium level and post October 2013 Keywords: Papaya Anthracnose Calcium Disease incidence Disease severity a b s t r a c

Biggs, Alan R.

154

Yeast ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisiae  

PubMed Central

Summary The growth kinetics and fermentation performance of Williopsis saturnus and Saccharomyces cerevisiae at ratios of 10:1, 1:1 and 1:10 (W.:S.) were studied in papaya juice with initial 7-day fermentation by W.?saturnus, followed by S.?cerevisiae. The growth kinetics of W.?saturnus were similar at all ratios, but its maximum cell count decreased as the proportion of S.?cerevisiae was increased. Conversely, there was an early death of S.?cerevisiae at the ratio of 10:1. Williopsis saturnus was the dominant yeast at 10:1 ratio that produced papaya wine with elevated concentrations of acetate esters. On the other hand, 1:1 and 1:10 ratios allowed the coexistence of both yeasts which enabled the flavour-enhancing potential of W.?saturnus as well as the ethyl ester and alcohol-producing abilities of S.?cerevisiae. In particular, 1:1 and 1:10 ratios resulted in production of more ethyl esters, alcohols and 2-phenylethyl acetate. However, the persistence of both yeasts at 1:1 and 1:10 ratios led to formation of high levels of acetic acid. The findings suggest that yeast ratio is a critical factor for sequential fermentation of papaya wine by W.?saturnus and S.?cerevisiae as a strategy to modulate papaya wine flavour. PMID:23171032

Lee, Pin-Rou; Kho, Stephanie Hui Chern; Yu, Bin; Curran, Philip; Liu, Shao-Quan

2013-01-01

155

High-yield production of a low-temperature-active polygalacturonase for papaya juice clarification.  

PubMed

A novel endo-polygalacturonase (endo-PG I) from Achaetomium sp. Xz8 was identified, overexpressed in Pichia pastoris, and characterized in this report. Recombinant endo-PG I is distinguished from other enzyme counterparts by its high activity towards polygalacturonic acid (49,934 U/ml) and high yield in the 15-l fermentor (2.13 g/l). It exhibits optimal activity at 45 °C and remained active over a broad temperature range of 0-80 °C. Distinct from most fungal polygalacturonases that have acidic pH optima, endo-PG I is optimally active at pH 6, similar to the pH of fresh papaya juice (5.7). Endo-PG I alone reduced the viscosity of papaya juice by 17.6%, and increased its transmittance by 59.1%. When combined with a commercial pectin methylesterase, it showed much higher efficiency with a synergy degree of more than 1.25. All these favourable enzymatic properties make endo-PG I attractive for potential applications in the juice industry. PMID:23871048

Tu, Tao; Meng, Kun; Bai, Yingguo; Shi, Pengjun; Luo, Huiying; Wang, Yaru; Yang, Peilong; Zhang, Yuhong; Zhang, Wei; Yao, Bin

2013-12-01

156

Helpful Tips for Chemigation of Papaya1 Kati L White, Teresa Olczyk, Jonathan Crane, Rafael Muoz-Carpena, Tina Dispenza, and Harry  

E-print Network

ABE 360 Helpful Tips for Chemigation of Papaya1 Kati L White, Teresa Olczyk, Jonathan Crane, Rafael/Vegetables, Miami-Dade County Extension, Homestead, FL; Jonathan Crane is Professor, TREC, Homestead, FL; Rafael

Migliaccio, Kati White

157

Fault-Tree Compiler  

NASA Technical Reports Server (NTRS)

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

Butler, Ricky W.; Boerschlein, David P.

1993-01-01

158

GA Tree: genetically evolved decision trees  

Microsoft Academic Search

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

Athanassios Papagelis; Dimitrios Kalles

2000-01-01

159

Advisory Note TREE HEALTH  

E-print Network

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

160

Evolution of tree nutrition.  

PubMed

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

Raven, John A; Andrews, Mitchell

2010-09-01

161

Role of irradiation in the green synthesis of silver nanoparticles mediated by fig (Ficus carica) leaf extract.  

PubMed

Biosynthesis of silver nanoparticles in an aqueous mixture of fig (Ficus carica) leaf extract and AgNO3 solution exposed to a set of irradiances at different wavelengths are studied. Nanoparticle formation for irradiances between 6.5 mW/cm(2) and 13.3 mW/cm(2) in the 330-550 nm wavelength range is investigated and the results are compared to those of the nanoparticles synthesized in the dark and under direct sunlight. Ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, along with particle size analysis and transmission electron microscopy are employed for the characterization of samples and extracts. Irradiance is found to have profound influence on the reduction rates. However, size and spherical shape of the nanoparticles are persistent, irrespective of irradiance and wavelength. Irradiance is discussed to influence the particle formation and aggregation rates through the formation of free radicals in the fig extract. PMID:25062061

Ulug, Bulent; Haluk Turkdemir, M; Cicek, Ahmet; Mete, Ahmet

2015-01-25

162

Kids for Trees  

NSDL National Science Digital Library

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

163

Training Tree Transducers  

Microsoft Academic Search

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

Jonathan Graehl; Kevin Knight; Jonathan May

2008-01-01

164

Extremely randomized trees  

Microsoft Academic Search

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

Pierre Geurts; Damien Ernst; Louis Wehenkel

2006-01-01

165

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

166

Boosting Decision Trees  

Microsoft Academic Search

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

Harris Drucker; Corinna Cortes

1995-01-01

167

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

168

Training Tree Transducers  

Microsoft Academic Search

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

Jonathan Graehl; Kevin Knight

2004-01-01

169

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

170

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

171

Multivariate Decision Trees  

Microsoft Academic Search

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

Carla E. Brodley; Paul E. Utgoff

1995-01-01

172

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.

173

EVOLVING ORTHOGONAL DECISION TREES  

Microsoft Academic Search

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

D. DUMITRESCU

2003-01-01

174

Growth of a Pine Tree  

ERIC Educational Resources Information Center

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

Rollinson, Susan Wells

2012-01-01

175

Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas  

SciTech Connect

The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.146 references.

Thomas, P.

1986-01-01

176

Reversible adaptive trees.  

PubMed

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

Kergosien, Yannick L

2013-09-01

177

Evidence that thermodynamic stability of papaya glutamine cyclase is only marginal.  

PubMed

Papaya glutamine cyclase (PQC), a glycoprotein with a molecular mass of 32,980 Da, is a minor constituent of the papaya latex protein fraction. In neutral aqueous solutions, PQC adopts an all-beta conformation and exhibits high resistance to both proteolysis and denaturation. Complete unfolding of PQC requires a combination of an acidic medium and chemical denaturant such as urea or guanidine hydrochloride. The unfolding process takes place through formation of an intermediate A state that accumulates in the absence of chemical denaturants and displays all the features of a molten globule state. The different conformational states-N (native), A (acid-inactivated), and U (unfolded)-have been characterized by means of circular dichroism measurements, fluorescence spectroscopies, Stokes radii determinations, and 8-anilino-1-naphtalenesulfonic acid (ANS) binding characteristics. The unfolding pathways of the enzyme was further studied to estimate thermodynamic parameters characterizing both transitions N if A and A if U. In its A state, PQC is catalytically inefficient and highly susceptible to proteolysis. Also, its thermodynamic stability is decreased by some 3-5 kcal/mol. Conversion of the native to the A state involves digging up of five amino functions together with protonation of four to five acidic groups with pK(a)s, in the native state, around 2.7. It proceeds both cooperatively and reversibly although, in vitro, the refolding process is slow. Unfolding of the A state, on the other hand, occurs with a low degree of cooperativity. The intermediate A state thus seems to be only marginally more stable than the unfolded state. The role of suspected internal ion pairs in the stabilization of the native state of this enzyme is discussed. PMID:12389212

Azarkan, Mohamed; Amrani, Amina; Zerhouni, Samira; Oberg, Keith A; Ruysschaert, Jean-Marie; Wintjens, René; Looze, Yvan

2002-12-01

178

TreeTFDB: An Integrative Database of the Transcription Factors from Six Economically Important Tree Crops for Functional Predictions and Comparative and Functional Genomics  

PubMed Central

Crop plants, whose productivity is affected by a wide range of growing and environmental conditions, are grown for economic purposes. Transcription factors (TFs) play central role in regulation of many biological processes, including plant development and responses to environmental stimuli, by activating or repressing spatiotemporal gene expression. Here, we describe the TreeTFDB (http://treetfdb.bmep.riken.jp/index.pl) that houses the TF repertoires of six economically important tree crop species: Jatropha curcas, papaya, cassava, poplar, castor bean and grapevine. Among these, the TF repertoire of J. curcas has not been reported by any other TF databases. In addition to their basic information, such as sequence and domain features, domain alignments, gene ontology assignment and sequence comparison, information on available full-length cDNAs, identity and positions of all types of known cis-motifs found in the promoter regions, gene expression data are provided. With its newly designed and friendly interface and its unique features, TreeTFDB will enable research community to predict the functions and provide access to available genetic resources for performing comparative and functional genomics of the crop TFs, either individually or at whole family level, in a comprehensive and convenient manner. PMID:23284086

Mochida, Keiichi; Yoshida, Takuhiro; Sakurai, Tetsuya; Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo; Tran, Lam-Son Phan

2013-01-01

179

Staphylococcal Enterotoxin A Gene-Carrying Staphylococcus aureus Isolated from Foods and Its Control by Crude Alkaloid from Papaya Leaves.  

PubMed

Staphylococcus aureus is a known pathogen causing intoxication by producing enterotoxins in food. Staphylococcal enterotoxin A is one of the enterotoxins commonly implicated in staphylococcal food poisoning. The ability of crude alkaloid extract from papaya leaves to inhibit the growth of S. aureus and staphylococcal enterotoxin A synthesis was investigated. Staphylococcal enterotoxin A gene-carrying S. aureus was isolated from raw milk and ready-to-eat foods. Crude alkaloid was extracted from ground, dried papaya leaves using ultrasonic-assisted extraction, and a MIC of the alkaloid was determined by the broth macrodilution method. Furthermore, S. aureus isolate was exposed to the crude alkaloid extract at one- and twofold MIC, and the expression of sea was subsequently analyzed using a quantitative reverse transcription real-time PCR. Ten isolates of S. aureus were obtained, and nine of those isolates were sea carriers. The yield of crude alkaloid extract was 0.48 to 1.82% per dry weight of papaya leaves. A MIC of crude alkaloid to S. aureus was 0.25 mg/ml. After exposure to the alkaloid at 0.25 and 0.5 mg/ml for 2 h, a significant increase in cycle threshold values of sea was observed. The sea was expressed 29 and 41 times less when S. aureus was exposed to crude alkaloid at one- and twofold MIC, respectively. This study revealed that crude alkaloid of papaya leaves could control staphylococcal enterotoxin A gene-carrying S. aureus by suppressing the expression of sea, in addition to the ability to inhibit the growth of S. aureus. The expression of sea was successfully quantified. PMID:25364936

Handayani, Lita; Faridah, Didah Nur; Kusumaningrum, Harsi D

2014-11-01

180

Friends of Trees  

NSDL National Science Digital Library

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

181

In Focus: The Tree  

NSDL National Science Digital Library

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

182

Decision Tree Induction Based on Efficient Tree Restructuring  

Microsoft Academic Search

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

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

1997-01-01

183

Protected trees A guide to tree preservation procedures  

E-print Network

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

184

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

185

Species integrity in trees.  

PubMed

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

Ortiz-Barrientos, Daniel; Baack, Eric J

2014-09-01

186

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

187

National Register of Big Trees  

NSDL National Science Digital Library

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

Forests, American

188

PLANTING TECHNIQUES FOR TREE SPADE DUG TREES1  

Microsoft Academic Search

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

Robert Birdel; Carl Whitcomb; B. L. Appleton

189

Trees Are Terrific!  

ERIC Educational Resources Information Center

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

Braus, Judy, Ed.

1992-01-01

190

Survival of Trees  

NSDL National Science Digital Library

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

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

191

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

192

Leonardo's Tree Theory  

NSDL National Science Digital Library

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

Werner, Suzanne K.

2003-03-01

193

Artificial Dendritic Trees  

Microsoft Academic Search

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

John G. Elias

1993-01-01

194

Thin Junction Trees  

Microsoft Academic Search

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

Francis R. Bach; Michael I. Jordan

2001-01-01

195

Trees for Mother Earth.  

ERIC Educational Resources Information Center

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

Greer, Sandy

1993-01-01

196

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

197

Tea tree oil  

MedlinePLUS

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

198

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

E-print Network

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

New Hampshire, University of

199

Traditional agroecosystems as conservatories and incubators of cultivated plant varietal diversity: the case of fig (Ficus carica L.) in Morocco  

PubMed Central

Background Traditional agroecosystems are known to host both large crop species diversity and high within crop genetic diversity. In a context of global change, this diversity may be needed to feed the world. Are these agroecosystems museums (i.e. large core collections) or cradles of diversity? We investigated this question for a clonally propagated plant, fig (Ficus carica), within its native range, in Morocco, but as far away as possible from supposed centers of domestication. Results Fig varieties were locally numerous. They were found to be mainly highly local and corresponded to clones propagated vegetatively. Nevertheless these clones were often sufficiently old to have accumulated somatic mutations for selected traits (fig skin color) and at neutral loci (microsatellite markers). Further the pattern of spatial genetic structure was similar to the pattern expected in natural population for a mutation/drift/migration model at equilibrium, with homogeneous levels of local genetic diversity throughout Moroccan traditional agroecosystems. Conclusions We conclude that traditional agroecosystems constitue active incubators of varietal diversity even for clonally propagated crop species, and even when varieties correspond to clones that are often old. As only female fig is cultivated, wild fig and cultivated fig probably constitute a single evolutionary unit within these traditional agroecosystems. Core collections, however useful, are museums and hence cannot serve the same functions as traditional agroecosystems. PMID:20167055

2010-01-01

200

Effects of Ficus carica paste on constipation induced by a high-protein feed and movement restriction in beagles  

PubMed Central

Constipation is one of the most common functional digestive complaints worldwide. We investigated the laxative effects of figs (Ficus carica L) in a beagle model of constipation induced by high protein diet and movement restriction. The experiments were consecutively conducted over 9 weeks divided into 3 periods of 3 weeks each. All 15 beagles were subjected to a non-treatment (control) period, a constipation induction period, and a fig paste treatment period. We administered fig paste (12 g/kg daily, by gavage) for 3 weeks following a 3-week period of constipation induction in dogs. Segmental colonic transit time (CTT) was measured by counting radiopaque markers (Kolomark) using a radiograph performed every 6 h after feeding Kolomark capsules, until capsules were no longer observed. Fig paste significantly increased fecal quantity in constipated dogs, and segmental CTT was also reduced following fig paste administration. There were no significant differences in feed intake, water intake, body weight, or blood test results, between the constipation and fig paste administration periods. Our results demonstrate that fig is an effective treatment for constipation in beagles. Specifically, stool weight increased and segmental CTT decreased. Fig pastes may be useful as a complementary medicine in humans suffering from chronic constipation. PMID:22232635

Oh, Hong-Geun; Lee, Hak-Yong; Seo, Min-Young; Kang, Young-Rye; Kim, Jung-Hoon; Park, Jung-Woo; Back, Hyang-Im; Kim, Sun-Young; Oh, Mi-Ra; Park, Soo-Hyun; Kim, Min-Gul; Jeon, Ji-Young; Hwang, Min-Ho; Shin, Sook-Jeong

2011-01-01

201

Generation of hermaphrodite transgenic papaya lines with virus resistance via transformation of somatic embryos derived from adventitious roots of in vitro shoots.  

PubMed

Papaya production is seriously limited by Papaya ringspot virus (PRSV) worldwide and Papaya leaf-distortion mosaic virus (PLDMV) in Eastern Asia. An efficient transformation method for developing papaya lines with transgenic resistance to these viruses and commercially desirable traits, such as hermaphroditism, is crucial to shorten the breeding program for this fruit crop. In this investigation, an untranslatable chimeric construct pYP08 containing truncated PRSV coat protein (CP) and PLDMV CP genes coupled with the 3' untranslational region of PLDMV, was generated. Root segments from different portions of adventitious roots of in vitro multiple shoots of hermaphroditic plants of papaya cultivars 'Tainung No. 2', 'Sunrise', and 'Thailand' were cultured on induction medium for regeneration into somatic embryos. The highest frequency of somatic embryogenesis was from the root-tip segments of adventitious roots developed 2-4 weeks after rooting in perlite medium. After proliferation, embryogenic tissues derived from somatic embryos were wounded in liquid-phase by carborundum and transformed by Agrobacterium carrying pYP08. Similarly, another construct pBG-PLDMVstop containing untranslatable CP gene of PLDMV was also transferred to 'Sunrise' and 'Thailand', the parental cultivars of 'Tainung No. 2'. Among 107 transgenic lines regenerated from 349 root-tip segments, nine lines of Tainung No. 2 carrying YP08 were highly resistant to PRSV and PLDMV, and 9 lines (8 'Sunrise' and 1 'Thailand') carrying PLDMV CP highly resistant to PLDMV, by a mechanism of post-transcriptional gene silencing. The hermaphroditic characteristics of the transgenic lines were confirmed by PCR with sex-linked primers and phenotypes of flower and fruit. Our approach has generated transgenic resistance to both PRSV and PLDMV with commercially desirable characters and can significantly shorten the time-consuming breeding programs for the generation of elite cultivars of papaya hybrids. PMID:19943109

Kung, Yi-Jung; Yu, Tsong-Ann; Huang, Chiung-Huei; Wang, Hui-Chin; Wang, Shin-Lan; Yeh, Shyi-Dong

2010-08-01

202

Lazy decision trees  

SciTech Connect

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

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

1996-12-31

203

Global Trees Campaign  

NSDL National Science Digital Library

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

204

Phylogenetic trees in bioinformatics  

SciTech Connect

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

Burr, Tom L [Los Alamos National Laboratory

2008-01-01

205

Prevention of cardiotoxicity of aflatoxin B1 via dietary supplementation of papaya fruit extracts in rats.  

PubMed

The aim of the current study was to evaluate the cardioprotective ability of water (WE) and ethanolic (EE) papaya fruits extracts against cardiotoxicity induced by aflatoxin B1 (AFB1) in rats. Forty two female Sprague-Dawley rats were divided into six treatment groups and treated orally for 2 weeks as follow: control group, the group treated with WE (250 mg/kg b.w), the group treated with EE (250 mg/kg b.w), the group treated orally with AFB1 (17 ?g/kg b.w) and the groups treated orally with AFB1 plus WE or EE. The results indicated that treatment with AFB1 resulted in oxidative stress in the heart manifested by the marked increase in cardiac malondialdehyde and calcium levels accompanied with a significant decrease in cardiac total antioxidant capacity. Serum nitric oxide and sodium levels, lactate dehydrogenase and creatine kinase isoenzyme activities were significantly increased, whereas, cardiac Na(+)/K(+)-ATPase activity and serum potassium were insignificantly affected. Supplementation with WE or EE effectively ameliorated most of the changes induced by AFB1. It could be concluded that both extracts attenuated the oxidative stress induced in heart tissue by AFB1 and WE was more pronounced due to the higher total phenolic contents than in the EE. PMID:23712331

Mannaa, Fathia A; Abdel-Wahhab, Khaled G; Abdel-Wahhab, Mosaad A

2014-03-01

206

Evolutionary tree reconstruction  

NASA Technical Reports Server (NTRS)

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

Cheeseman, Peter; Kanefsky, Bob

1990-01-01

207

Learning classification trees  

NASA Technical Reports Server (NTRS)

Algorithms for learning classification trees have had successes in artificial intelligence and statistics over many years. How a tree learning algorithm can be derived from Bayesian decision theory is outlined. This introduces Bayesian techniques for splitting, smoothing, and tree averaging. The splitting rule turns out to be similar to Quinlan's information gain splitting rule, while smoothing and averaging replace pruning. Comparative experiments with reimplementations of a minimum encoding approach, Quinlan's C4 and Breiman et al. Cart show the full Bayesian algorithm is consistently as good, or more accurate than these other approaches though at a computational price.

Buntine, Wray

1991-01-01

208

Combining Binary Search Trees  

E-print Network

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

Demaine, Erik D.

209

The tree BVOC index.  

PubMed

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

Simpson, J R; McPherson, E G

2011-01-01

210

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

211

Generalized constructive tree weights  

NASA Astrophysics Data System (ADS)

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

Rivasseau, Vincent; Tanasa, Adrian

2014-04-01

212

Construct a phylogenetic tree  

NSDL National Science Digital Library

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

White, Brian

2012-06-28

213

Life of a Tree  

NSDL National Science Digital Library

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

Foundation, Wgbh E.

2007-08-09

214

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

215

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

216

Core Based Trees (CBT)  

Microsoft Academic Search

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

Tony Ballardie; Paul Francis; Jon Crowcroft

1993-01-01

217

Handy Family Tree  

NSDL National Science Digital Library

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

Utah, University O.

2006-01-01

218

Peach Tree Pruning.  

E-print Network

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

Lyons, Calvin G.

1986-01-01

219

On Trees and Logs  

Microsoft Academic Search

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

Anna Pavlova; David Cass

2002-01-01

220

ON TREES AND LOGS  

Microsoft Academic Search

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

David Cass; Anna Pavlova

2003-01-01

221

Tree nut allergy  

Microsoft Academic Search

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

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

2003-01-01

222

How Trees Can Save Energy.  

ERIC Educational Resources Information Center

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

Fazio, James R., Ed.

1991-01-01

223

Carbon Sequestration in Campus Trees  

NSDL National Science Digital Library

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

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

224

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

225

Growth stock: trees for California  

Microsoft Academic Search

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

1982-01-01

226

The Ubiquitous B-Tree  

Microsoft Academic Search

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

Douglas E. Comer

1979-01-01

227

Tree domestication in tropical agroforestry  

Microsoft Academic Search

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

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

2004-01-01

228

Inhibitory effect of essential oils against Colletotrichum gloeosporioides and Rhizopus stolonifer in stored papaya fruit and their possible application in coatings  

Microsoft Academic Search

The aim of this study was to evaluate the fungicidal effect of the thyme and Mexican lime essential oils studies against Colletotrichum gloeosporioides and Rhizopus stolonifer, and to determine the possibility of incorporating them in edible coatings to control postharvest diseases of papaya fruits.For in vitro studies, both essential oils were tested to evaluate their effect on mycelial growth of

E. Bosquez-Molina; E. Ronquillo-de Jesús; S. Bautista-Baños; J. R. Verde-Calvo; J. Morales-López

2010-01-01

229

Proteasome-Independent Major Histocompatibility Complex Class I Cross-Presentation Mediated by Papaya Mosaic Virus-Like Particles Leads to Expansion of Specific Human T Cells  

Microsoft Academic Search

The development of versatile vaccine platforms is a priority that is recognized by health authorities worldwide; such platforms should induce both arms of the immune system, the humoral and cytotoxic-T- lymphocyte responses. In this study, we have established that a vaccine platform based on the coat protein of papaya mosaic virus (PapMV CP), previously shown to induce a humoral response,

Denis Leclerc; Diane Beauseigle; Jerome Denis; Helene Morin; Christine Pare; Alain Lamarre; Rejean Lapointe

2007-01-01

230

Assessments of Biodiversity Based on Molecular Markers and Morphological Traits among West-Bank, Palestine Fig Genotypes (Ficus carica L.)  

E-print Network

-East regions, and subsequently across the rest of the World [5]. In Palestine, fig trees are grown historically all over the country and are mostly located on marginal lands, in combination with other fruit trees (mainly olive and grape), or are scattered... Mediterranean climate, with mild tem- peratures (18?C - 25?C), rainy weather (580 - 800 mm/year) in autumn and winter, and hot, dry summers. Generally, all fig trees are cultivated under rain-fed conditions. 2.1.2. DNA Extraction Genomic DNA was extracted...

Basheer-Salimia, Rezq; Awad, Murad; Ward, Joy K.

2012-09-26

231

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

232

Trees and Carbon  

NSDL National Science Digital Library

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

Pratte, John

233

Trees from the Seas  

NSDL National Science Digital Library

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

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

2007-06-17

234

Learning Tractable Graphical Models: Latent Trees and Tree Mixtures  

E-print Network

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

Anandkumar, Animashree

235

Global Tree Optimization: A Non-greedy Decision Tree Algorithm  

Microsoft Academic Search

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

Kristin P. Bennett

1994-01-01

236

Recursive queries on trees and data trees Serge Abiteboul  

E-print Network

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

Paris-Sud XI, Université de

237

Tree Fertilization Soil Analysis  

E-print Network

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

238

Induction of decision trees  

Microsoft Academic Search

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

J. Ross Quinlan

1986-01-01

239

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

240

The Medicine Tree.  

ERIC Educational Resources Information Center

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

Brokenleg, Martin

2000-01-01

241

Learning in Boltzmann Trees  

Microsoft Academic Search

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

Lawrence K. Saul; Michael I. Jordan

1994-01-01

242

Hidden Markov Decision Trees  

Microsoft Academic Search

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

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

1996-01-01

243

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

244

Fuzzy fault tree analysis  

Microsoft Academic Search

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

David P. Weber

1994-01-01

245

Palm Tree Peroxidases  

Microsoft Academic Search

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

I. Yu. Sakharov

2004-01-01

246

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.

247

Measure a Tree  

NSDL National Science Digital Library

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

248

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

249

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

250

The Sacred Tree.  

ERIC Educational Resources Information Center

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

Lethbridge Univ. (Alberta).

251

An Introduction to Tree Diagrams  

NSDL National Science Digital Library

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

Cork, Stu

2014-01-01

252

Classify the trees/Leaves  

NSDL National Science Digital Library

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

Walsh, Mary

253

Flat Tree Oyster (Isognomon alatus)  

USGS Multimedia Gallery

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

2010-05-03

254

Tree of Life Workshop Report  

NSF Publications Database

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

255

Can These Trees Be Saved?  

E-print Network

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

Taylor, Eric; Foster, C. Darwin

2005-10-19

256

Learning with Mixtures of Trees  

Microsoft Academic Search

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

Marina Meila; Michael I. Jordan

2000-01-01

257

Street Trees and Intersection Safety  

Microsoft Academic Search

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

Elizabeth Macdonald; Alethea Harper; Jason A. Hayter

2006-01-01

258

Rate of tree carbon accumulation increases continuously with tree size  

USGS Publications Warehouse

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

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

2014-01-01

259

Climate change & street trees project  

E-print Network

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

260

Building Your Own Abseil Tree.  

ERIC Educational Resources Information Center

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

Barnett, Des

2002-01-01

261

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

262

Failure Diagnosis Using Decision Trees  

Microsoft Academic Search

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

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

2004-01-01

263

Genetic conservation of native trees  

E-print Network

, 2001). Chloroplast DNA investigations have continued and include work on veteran oak treesGenetic conservation of native trees Scott McG. Wilson1 and C. J. A. Samuel Over recent years, the genetic conservation of British native tree populations has become an increasingly important part

264

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.

265

Multivariate versus Univariate Decision Trees  

Microsoft Academic Search

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

Carla E. Brodley; Paul E. Utgoff

1992-01-01

266

Building up rhetorical structure trees  

SciTech Connect

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

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

1996-12-31

267

Selecting Landscape Plants: Shade Trees  

E-print Network

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

Liskiewicz, Maciej

268

The Re-Think Tree.  

ERIC Educational Resources Information Center

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

Gear, Jim

1993-01-01

269

Rate of tree carbon accumulation increases continuously with tree size  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

270

Rate of tree carbon accumulation increases continuously with tree size.  

PubMed

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

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

2014-03-01

271

Red-black Tree Jingjing Xia  

E-print Network

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

Chen, Yangjun

272

Fault-Tree Compiler Program  

NASA Technical Reports Server (NTRS)

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

Butler, Ricky W.; Martensen, Anna L.

1992-01-01

273

Global Value Trees  

E-print Network

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

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

2014-01-01

274

On trees and logs  

Microsoft Academic Search

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

David Cass; Anna Pavlova

2004-01-01

275

Counting Spanning Trees Diplomarbeit  

E-print Network

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

Krattenthaler, Christian

276

TreeFix: Statistically Informed Gene Tree Error Correction Using Species Trees  

PubMed Central

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

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

2013-01-01

277

CST-Trees: Cache Sensitive T-Trees  

Microsoft Academic Search

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

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

2007-01-01

278

IN VITRO EFFICACY OF SOME INDIGENOUS PLANTS ON THE INHIBITION OF DEVELOPMENT OF EGGS OF ASCARIDIA GALLI (DIGENIA: NEMATODA)  

Microsoft Academic Search

In vitro efficacy of five indigenous plants namely Bishkatali (Polygonum hydropiper), Neem (Azadirachta indica), Papaya (Carica papaya), Korolla (Momordica charantia) and Mahogany (Swietenia macrophylla) were studied against the development of Ascaridia galli eggs from July 2007 to May 2008. Fresh juice, extracts and dust of leaves were tested. Fresh juice of leaves were trialed at 5%, 10% and 20% concentrations;

K. R. Islam; T. Farjana; N. Begum; M. M. H. Mondal

2008-01-01

279

The fault-tree compiler  

NASA Technical Reports Server (NTRS)

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

Martensen, Anna L.; Butler, Ricky W.

1987-01-01

280

Diameter-Constrained Steiner Tree  

NASA Astrophysics Data System (ADS)

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

Ding, Wei; Lin, Guohui; Xue, Guoliang

281

Dimers, Tilings and Trees  

E-print Network

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

Richard Kenyon; Scott Sheffield

2003-10-13

282

Ice Roads: Steiner Trees  

NSDL National Science Digital Library

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

Bell, Tim; Witten, Ian; Fellows, Mike

1998-01-01

283

Exploring Trees and Ponds  

NSDL National Science Digital Library

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

284

Fires on trees  

E-print Network

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

Bertoin, Jean

2010-01-01

285

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

286

A Tree of Genetic Traits  

NSDL National Science Digital Library

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

Malone, Molly; Starr, Harmony; Mitchell, April

2006-01-01

287

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

288

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

289

Incremental Induction of Decision Trees  

Microsoft Academic Search

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

Paul E. Utgoff; Pat Langley

1989-01-01

290

Genetically optimized fuzzy decision trees  

Microsoft Academic Search

In this study, we are concerned with genetically optimized fuzzy decision trees (G-DTs). Decision trees are fundamental architectures of machine learning, pattern recognition, and system modeling. Starting with the generic decision tree with discrete or interval-valued attributes, we develop its fuzzy set-based generalization. In this generalized structure we admit the values of the attributes that are represented by some membership

Witold Pedrycz; Zenon A. Sosnowski

2005-01-01

291

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

292

Relating phylogenetic trees to transmission trees of infectious disease outbreaks.  

PubMed

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

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

2013-11-01

293

CartograTree: connecting tree genomes, phenotypes and environment.  

PubMed

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

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

2013-05-01

294

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

295

Do Invasive Trees have a Hydraulic Advantage over Native Trees?  

Microsoft Academic Search

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

R B Pratt; R A Black

2006-01-01

296

Integrality ratio for Group Steiner Trees and Directed Steiner Trees  

Microsoft Academic Search

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

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

297

Supporting Medical Decisions with Vector Decision Trees  

Microsoft Academic Search

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

Peter Kokol; Norihiro Sakamoto

298

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

299

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

300

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

E-print Network

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

Alechina, Natasha

301

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

302

Competitive learning in decision trees  

NASA Astrophysics Data System (ADS)

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

Martinez, Dominique

1998-07-01

303

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

304

Beta Diffusion Trees Creighton Heaukulani  

E-print Network

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

Edinburgh, University of

305

Information Processing in Dendritic Trees  

Microsoft Academic Search

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

Bartlett W. Mel

1994-01-01

306

TREE FAILURES AND ACCIDENTS IN  

E-print Network

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

Standiford, Richard B.

307

AFTP Fault Tree Analysis Program  

Microsoft Academic Search

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

Richard A. Pullen

1984-01-01

308

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

309

Genome Trees from Conservation Profiles  

PubMed Central

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

Tekaia, Fredj; Yeramian, Edouard

2005-01-01

310

Packing Steiner trees Microsoft Research  

E-print Network

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

Salavatipour, Mohammad R.

311

Elemental composition of tree nuts  

Microsoft Academic Search

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

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

1979-01-01

312

In Search of Moon Trees  

NSDL National Science Digital Library

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

Phillips, Tony.

2002-01-01

313

On Cartesian trees and range minimum queries  

E-print Network

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

Demaine, Erik D.

314

7 CFR 1214.3 - Christmas tree.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

315

Definition Synaptic Integration in Dendritic Trees  

E-print Network

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

Alford, Simon

316

Tree preserving embedding  

PubMed Central

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

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

2011-01-01

317

Tree reconstruction from partial orders  

SciTech Connect

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

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

1993-03-01

318

Tree reconstruction from partial orders  

SciTech Connect

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

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

1993-01-01

319

A Cost Benefit Analysis of Urban Trees  

SciTech Connect

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

Akbari, Hashem

1997-09-01

320

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

E-print Network

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

New Hampshire, University of

321

Translating innate response into long-lasting antibody response by the intrinsic antigen-adjuvant properties of papaya mosaic virus  

PubMed Central

Identifying the properties of a molecule involved in the efficient activation of the innate and adaptive immune responses that lead to long-lasting immunity is crucial for vaccine and adjuvant development. Here we show that the papaya mosaic virus (PapMV) is recognized by the immune system as a pathogen-associated molecular pattern (PAMP) and as an antigen in mice (Pamptigen). A single immunization of PapMV without added adjuvant efficiently induced both cellular and specific long-lasting antibody responses. PapMV also efficiently activated innate immune responses, as shown by the induction of lipid raft aggregation, secretion of pro-inflammatory cytokines, up-regulation of co-stimulatory molecules on dendritic cells and macrophages, and long-lasting adjuvant effects upon the specific antibody responses to model antigens. PapMV mixed with Salmonella enterica serovar Typhi (S. typhi) outer membrane protein C increased its protective capacity against challenge with S. typhi, revealing the intrinsic adjuvant properties of PapMV in the induction of immunity. Antigen-presenting cells loaded with PapMV efficiently induced antibody responses in vivo, which may link the innate and adaptive responses observed. PapMV recognition as a Pamptigen might be translated into long-lasting antibody responses and protection observed. These properties could be used in the development of new vaccine platforms. PMID:18070030

Acosta-Ramirez, Elizabeth; Perez-Flores, Rebeca; Majeau, Nathalie; Pastelin-Palacios, Rodolfo; Gil-Cruz, Cristina; Ramirez-Saldana, Maricela; Manjarrez-Orduno, Nataly; Cervantes-Barragan, Luisa; Santos-Argumedo, Leopoldo; Flores-Romo, Leopoldo; Becker, Ingeborg; Isibasi, Armando; Leclerc, Denis; Lopez-Macias, Constantino

2008-01-01

322

Tree SelectionTree Selection Why is selection important?  

E-print Network

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

323

AVL Tree Applet  

NSDL National Science Digital Library

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

Gogeshvili, Arsen

324

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

325

Plasma cholinesterase inhibition in the clay-colored robin (Turdus grayi) exposed to diazinon in maradol papaya crops in Yucatan, Mexico [Inhibicio??n de colinesterasa plasma??tica en el zorzal pardo (Turdus grayi), expuesto a diazino??n en cultivos de papaya maradol en Yucata??n, Me??xico  

USGS Publications Warehouse

The use of organophosphorous pesticides in agriculture can result in intoxication of birds foraging in sprayed crops. Effects on birds resulting from pesticide intoxication are varied and include behavioral and reproductive effects, including death. One widely used insecticide in Maradol papaya crops is diazinon which has been associated with various incidents of intoxication and death of wild birds. The objective of this study was to evaluate the impact of diazinon application to papaya crops on plasma cholinesterase activity of the clay-colored robin (Turdus grayi). We captured clay-colored robins foraging in a papaya crop the following day after the field had been sprayed with diazinon at a dose of 1.5 kg/ha during March and May, respectively. We took a blood sample from the brachialis vein of the birds captured and measured plasma enzymatic activity. The plasma samples from birds used as controls were taken during the same time period and were analyzed in a similar way. Enzymatic activity of males was greater than that of females (53,52%) and mean cholinesterase inhibition was 49.43%. Cholinesterase inhibition was greater during May than in March probably due to more continuous exposure and ingestion of the insecticide through food and possible absorption through the skin. This degree of enzymatic inhibition is possibly affecting the behavior of the clay-colored robin and could result in death in severe cases.

Cobos, V. M.; Mora, M. A.; Escalona, G.

2006-01-01

326

Vascularization with trees that alternate with upside-down trees  

NASA Astrophysics Data System (ADS)

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

Zhang, Houlei; Lorente, Sylvie; Bejan, Adrian

2007-05-01

327

Integrality ratio for group Steiner trees and directed steiner trees  

Microsoft Academic Search

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

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

2003-01-01

328

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

E-print Network

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

New Hampshire, University of

329

N-terminal of Papaya ringspot virus type-W (PRSV-W) helper component proteinase (HC-Pro) is essential for PRSV systemic infection in zucchini.  

PubMed

The Papaya ringspot virus (PRSV) is one of the limiting factors affecting papaya and cucurbits production worldwide. PRSV belongs to the potyvirus genus which consists of 30% of known plant viruses. Two serological closely related strains, namely type-P and -W, have been reported. PRSV type-P infects both papaya and cucurbits, while type-W infects only cucurbits. The genome of PRSV Thailand isolate consists of a (+) RNA molecule of 10323 nucleotides, which is first translated into a single polypeptide and further cleaved by three viral encoded proteases into ten gene products. Helper-component proteinase (HC-Pro), which is encoded by the 2nd cistron of the potyviral genome, has been implicated in aphid transmission, viral movement, viral replication and suppression of host viral defense system. Studies of the Tobacco etch virus (TEV), Lettuce mosaic virus (LMV), Onion yellow dwarf virus (OYDV) and Wheat streak mosaic virus (WSMV) indicate that the N-terminal of HC-Pro is dispensable for systemic infection in their respective hosts. However, deletion analysis of the Tobacco vein mottling virus (TVMV) indicates otherwise. In this study, we examined whether HC-Pro is essential for PRSV systemic infection in cucurbits and the role of its N-terminal in systemic infection. Our results indicated that HC-Pro is indispensable for PRSV infection in zucchini. Deletion analysis of PRSV HC-Pro showed that deletion of as few as 54 amino acids at the N-terminal of HC-Pro completely abolished the infectivity of the corresponding cDNA clone. Therefore, it is proposed that the N-terminal of HC-Pro is involved in systemic infection of PRSV, in addition to its conserved function in aphid transmission. PMID:19322647

Yap, Yun-Kiam; Duangjit, Janejira; Panyim, Sakol

2009-06-01

330

Summing tree graphs at threshold  

NASA Astrophysics Data System (ADS)

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

Brown, Lowell S.

1992-11-01

331

Learning Latent Tree Graphical Models  

E-print Network

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

Choi, Myung Jin

332

Millersville University's Trees of Distinction  

E-print Network

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

Hardy, Christopher R.

333

Cultural Values of Trees, Woods  

E-print Network

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

334

Limit theorems for random trees.  

PubMed Central

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

Takacs, L

1992-01-01

335

Fault Tree Analysis: A Bibliography  

NASA Technical Reports Server (NTRS)

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

2000-01-01

336

The Alternating Decision Tree Learning Algorithm  

Microsoft Academic Search

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

Yoav Freund; Llew Mason

1999-01-01

337

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

338

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

339

Tree-structured approximations by expectation propagation  

E-print Network

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

Minka,Tom

340

Water in the trunk of a tree  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (AAAS;)

2005-12-22

341

A Tool for Displaying Syntactic Trees.  

ERIC Educational Resources Information Center

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

Morgan, Jerry L.

342

A Compendium on Steiner Tree Problems  

E-print Network

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

Behnke, Sven

343

Generic physical protection logic trees  

SciTech Connect

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

Paulus, W.K.

1981-10-01

344

If a Tree Falls in the Forest ...  

NSDL National Science Digital Library

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

345

Parallel TreeSPH  

NASA Astrophysics Data System (ADS)

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

Davé, Romeel; Dubinski, John; Hernquist, Lars

1997-08-01

346

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

347

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

348

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

349

BlobTree Trees Callum Galbraith Peter MacMurchy Brian Wyvill  

E-print Network

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

Wyvill, Brian

350

Self-adjusting binary search trees  

Microsoft Academic Search

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

Daniel Dominic Sleator; Robert Endre Tarjan

1985-01-01

351

Transgenic Papaya Genome Sequenced http://www.genomeweb.com/issues/news/146481-1.html?type=pf 1 of 2 4/27/2008 7:12 PM  

E-print Network

and China and was led by Maqsudal Alam, the director of the University of Hawaii's Advanced Studies in Genomics Proteomics and Bioinformatics program. The team sequenced 75 percent of the entire papaya genome and function. Using Southern blot analysis, they identified three transgenic insertions in the SunUp nuclear

Alam, Maqsudul

352

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

NSF Publications Database

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

353

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

E-print Network

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

Liang, Y. Daniel

354

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

Microsoft Academic Search

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

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

2007-01-01

355

Trees, soils, and food security  

PubMed Central

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

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

1997-01-01

356

Attention trees and semantic paths  

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

357

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

E-print Network

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

New Hampshire, University of

358

Simplicial matrix-tree theorems  

E-print Network

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

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

2009-01-01

359

Interpreting the universal phylogenetic tree  

NASA Technical Reports Server (NTRS)

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

Woese, C. R.

2000-01-01

360

Multiple Tree for Partially Observable Monte-Carlo Tree Search  

E-print Network

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

Auger, David

2011-01-01

361

Tree Height Calculator: An Android App for Estimating Tree Height  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

362

The most parsimonious tree for random data.  

PubMed

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

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

2014-11-01

363

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

364

SHADE TREE LEAF SCORCH1  

Microsoft Academic Search

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

R. Hammerschlag; J. Sherald; S. Kostka

1983-01-01

365

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

366

General Fragmentation Trees Robin Stephenson  

E-print Network

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

Paris-Sud XI, Université de

367

Tree coding of image subbands.  

PubMed

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

Nanda, S; Pearlman, W A

1992-01-01

368

Supervised Harvesting of Expression Trees  

Microsoft Academic Search

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

Trevor Hastie; Robert Tibshirani; David Botstein; Patrick Brown

2000-01-01

369

Supervised harvesting of expression trees  

Microsoft Academic Search

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

Trevor Hastie; Robert Tibshirani; David Botstein; Patrick Brown

2001-01-01

370

Tree pits as urban gardens  

Microsoft Academic Search

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

Steven Strom

1990-01-01

371

The Tree of Life Project  

ERIC Educational Resources Information Center

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

Milbrath, Sherry

2009-01-01

372

Human Arterial-Tree Multiscale  

E-print Network

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

373

(Nitrogen deposition to forest trees)  

Microsoft Academic Search

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

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

1989-01-01

374

Synaptic integration in dendritic trees  

Microsoft Academic Search

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

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

2005-01-01

375

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

376

Tree topologies in ATM networks  

Microsoft Academic Search

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

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

1992-01-01

377

Fires on trees Jean Bertoin  

E-print Network

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

Paris-Sud XI, Université de

378

Electric Trees and Pond Creatures.  

ERIC Educational Resources Information Center

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

Weaver, Helen; Hounshell, Paul B.

1978-01-01

379

Limit of random walks of random trees  

E-print Network

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

Marckert, Jean-François

380

Generating Functions for Multi-labeled Trees  

PubMed Central

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

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

2012-01-01

381

Propagating Belief Functions in AND-Trees  

E-print Network

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

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

1995-01-01

382

SOLVING STEINER TREE PROBLEMS IN GRAPHS WITH ...  

E-print Network

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

383

Exploring the Secret Life of Trees  

NSDL National Science Digital Library

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

384

Trees are Terrific...Travels with Pierre  

NSDL National Science Digital Library

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

385

Texas Wholesale Market for Christmas Trees.  

E-print Network

Wholesale Market for 7 :. @EXAS A&M UNIVERSITY . TEXAS AGRICULTURAL EXPERIMENT STATION R. E. Patterson, Director, College Station, Texas trees might capture as much as one-half of the more than 2 million Texas evergreen tree market. Wl...~olesale Christmas tree markets for Dallas, Houston and San Antonio were investigated during the 1962 Holiday Season to determine potential outlets for locally grown trees. The investigation was limited to species which could be grown in at least a part...

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

1964-01-01

386

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

387

A complete fuzzy decision tree technique  

Microsoft Academic Search

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

Cristina Olaru; Louis Wehenkel

2003-01-01

388

Methane Emissions from Deciduous Trees  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

389

TreeDyn: towards dynamic graphics and annotations for analyses of trees  

PubMed Central

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

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

2006-01-01

390

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

Microsoft Academic Search

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

JAKE SCHEPPS; STEVE LOHR; THOMAS E. MARTIN

391

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

Microsoft Academic Search

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

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

2011-01-01

392

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

E-print Network

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

Boyer, Edmond

393

ForPeerReview Tree diversity enhances tree transpiration in a Panamanian  

E-print Network

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

Bermingham, Eldredge

394

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

E-print Network

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

Anandkumar, Animashree

395

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

E-print Network

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

Anandkumar, Animashree

396

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

Microsoft Academic Search

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

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

2010-01-01

397

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

Microsoft Academic Search

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

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

2011-01-01

398

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

399

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

E-print Network

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

Krauthgamer, Robert

400

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

E-print Network

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

Kortsarz, Guy

401

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

E-print Network

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

Keinan, Alon

402

Breanne Mc Ivor The Mango Tree  

E-print Network

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

Robertson, Stephen

403

Generating Production Rules from Decision Trees  

Microsoft Academic Search

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

J. Ross Quinlan

1987-01-01

404

Where are the young Brazil nut trees?  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (AAAS;)

2003-12-19

405

Mining optimal decision trees from itemset lattices  

Microsoft Academic Search

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

Siegfried Nijssen; Élisa Fromont

2007-01-01

406

Decision Tree Learning Goals for the lecture  

E-print Network

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

Page Jr., C. David

407

Tree Protection During Construction and Landscaping Activities  

Microsoft Academic Search

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

Todd Hurt

408

Research Summary Health Benefits of Street Trees  

E-print Network

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

409

Cache-oblivious dynamic search trees  

E-print Network

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

Kasheff, Zardosht, 1981-

2004-01-01

410

Data multiplexer using a tree switch  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

411

Original article Oak tree improvement in Indiana  

E-print Network

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

Paris-Sud XI, Université de

412

Approximability of Selected Phylogenetic Tree Problems  

E-print Network

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

Eckmiller, Rolf

413

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

414

Fault tree analysis with fuzzy gates  

Microsoft Academic Search

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

HanSuk Pan; WonYoung Yun

1997-01-01

415

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

416

Safety Requirements and Fault Trees using Retrenchment  

E-print Network

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

Banach, Richard

417

Hardwood Tree Improvement and Regeneration Center  

E-print Network

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

418

Skip B-Trees Ittai Abraham1  

E-print Network

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

Aspnes, James

419

Malcolm Guite The Magic Apple Tree  

E-print Network

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

Robertson, Stephen

420

"Dangerous" urban trees & community health & safety  

E-print Network

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

421

Mechanical stability of trees under dynamic loads  

Microsoft Academic Search

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

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

2006-01-01

422

Minimum Steiner Tree Construction Gabriel Robins  

E-print Network

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

Robins, Gabriel

423

Improved approximations for the Steiner tree problem  

Microsoft Academic Search

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

Piotr Berman; Viswanathan Ramaiyer

1992-01-01

424

Revised May 2008 Wildlife/Danger Tree  

E-print Network

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

Northern British Columbia, University of

425

New decision tree based on genetic algorithm  

Microsoft Academic Search

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

Shiueng-Bien Yang; Shen-I Yang

2010-01-01

426

Parallel Genetic Programming for Decision Tree Induction  

E-print Network

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

Fernandez, Thomas

427

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

E-print Network

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

428

On the Hardness of Full Steiner Tree Problems Ahmad Biniaz  

E-print Network

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

Smid, Michiel

429

Batch-mode Supervised Learning Decision tree induction  

E-print Network

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

Wehenkel, Louis

430

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

E-print Network

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

Alechina, Natasha

431

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

E-print Network

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

Alechina, Natasha

432

Anatomical modeling of the bronchial tree  

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

433

Fluid forces acting on a tree  

NASA Astrophysics Data System (ADS)

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

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

434

On finding minimum-diameter clique trees  

SciTech Connect

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

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

1991-08-01

435

Tree decompositions and social graphs  

E-print Network

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

Adcock, Aaron B; Mahoney, Michael W

2014-01-01

436

Differential Gene Expression in Response to Papaya ringspot virus Infection in Cucumis metuliferus Using cDNA- Amplified Fragment Length Polymorphism Analysis  

PubMed Central

A better understanding of virus resistance mechanisms can offer more effective strategies to control virus diseases. Papaya ringspot virus (PRSV), Potyviridae, causes severe economical losses in papaya and cucurbit production worldwide. However, no resistance gene against PRSV has been identified to date. This study aimed to identify candidate PRSV resistance genes using cDNA-AFLP analysis and offered an open architecture and transcriptomic method to study those transcripts differentially expressed after virus inoculation. The whole genome expression profile of Cucumis metuliferus inoculated with PRSV was generated using cDNA-amplified fragment length polymorphism (cDNA-AFLP) method. Transcript derived fragments (TDFs) identified from the resistant line PI 292190 may represent genes involved in the mechanism of PRSV resistance. C. metuliferus susceptible Acc. 2459 and resistant PI 292190 lines were inoculated with PRSV and subsequently total RNA was isolated for cDNA-AFLP analysis. More than 400 TDFs were expressed specifically in resistant line PI 292190. A total of 116 TDFs were cloned and their expression patterns and putative functions in the PRSV-resistance mechanism were further characterized. Subsequently, 28 out of 116 candidates which showed two-fold higher expression levels in resistant PI 292190 than those in susceptible Acc. 2459 after virus inoculation were selected from the reverse northern blot and bioinformatic analysis. Furthermore, the time point expression profiles of these candidates by northern blot analysis suggested that they might play roles in resistance against PRSV and could potentially provide valuable information for controlling PRSV disease in the future. PMID:23874746

Lin, Chia-Wei; Chung, Chien-Hung; Chen, Jo-Chu; Yeh, Shy-Dong; Ku, Hsin-Mei

2013-01-01

437

Organic & Integrated Tree Fruit Production  

NSDL National Science Digital Library

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

2007-08-02

438

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

439

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

440

Cover trees for nearest neighbor  

Microsoft Academic Search

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

Alina Beygelzimer; Sham Kakade; John Langford

2006-01-01

441

Statistical mechanics of steiner trees.  

PubMed

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

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

2008-07-18

442

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

443

Tree climbing and human evolution  

PubMed Central

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

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

2013-01-01

444

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

PubMed

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

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

2013-01-01

445

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

Microsoft Academic Search

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

Chih-Chiang Wei; Nien-Sheng Hsu

2008-01-01

446

Topic Modeling with Nonparametric Markov Tree  

PubMed Central

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

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

2013-01-01

447

Effective resistance of random trees  

Microsoft Academic Search

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

Louigi Addario-Berry; Nicolas Broutin; Gábor Lugosi

2009-01-01

448

Tree canopy radiance measurement system  

NASA Technical Reports Server (NTRS)

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

Caldwell, William; Vanderbilt, V. C.

1989-01-01

449

Can You Read a Tree?  

NSDL National Science Digital Library

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

Fries-Gaither, Jessica

2011-07-01

450

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

451

Hibernation by tree-roosting bats  

Microsoft Academic Search

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

Christopher Turbill; Fritz Geiser

2008-01-01

452

Reconciliation with Non-Binary Species Trees  

PubMed Central

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

Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton

2008-01-01

453

Maximum Bounded Rooted-Tree Packing Problem  

E-print Network

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

Kerivin, Herve; Simon, Gwendal; Zhou, Fen

2011-01-01

454

Signs of Change: Studying Tree Rings  

NSDL National Science Digital Library

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

Colberg, Nancy; Change, Northern C.

455

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

E-print Network

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

Kaminka, Gal A.

456

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

E-print Network

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

457

Tree-Structured Infinite Sparse Factor Model  

PubMed Central

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

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

2013-01-01

458

[Potential ecological risks of transgenic trees].  

PubMed

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

Kang, Xiangyang; Liu, Zhimin; Li, Shenggong

2004-07-01

459

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

460

Tree ring record chronicles major Mesoamerican droughts  

NASA Astrophysics Data System (ADS)

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

Tretkoff, Ernie

2011-05-01

461

Tree Genetics & Genomes ISSN 1614-2942  

E-print Network

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

462

Multicriteria Steiner Tree Problem for Communication Network  

E-print Network

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

Levin, Mark Sh

2011-01-01

463

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

Microsoft Academic Search

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

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

2000-01-01

464

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

SciTech Connect

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

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

2013-04-01

465

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

Microsoft Academic Search

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

SAI-CHEONG NG; KWONG-SAK LEUNG

466

A tree grows in Seattle.  

PubMed

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

1978-01-01

467

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

E-print Network

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

Deville, Yves

468

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

E-print Network

Street tree valuation systems The Capital Asset Value for Amenity Trees (CAVAT) scheme provides a duty on local authorities to protect trees in the public interest. However, it does not prescribe how-scale community evaluations, but can also handle urban woodlands. Funding/support Funded by the Forestry

469

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

E-print Network

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

Boyer, Edmond

470

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

Microsoft Academic Search

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

D. Hocking; K. Islam

1995-01-01

471

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

E-print Network

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

472

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

E-print Network

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

Rosenberg, Noah

473

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

E-print Network

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

Demaine, Erik

474

NodeWeighted Steiner Tree and Group Steiner Tree in Planar Graphs  

E-print Network

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

Demaine, Erik

475

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

E-print Network

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

Rosenberg, Noah

476

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.

477

GIS product reliability analysis based fuzzy fault tree  

Microsoft Academic Search

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

Xianfeng Ye; Youjian Hu; Shengwu Hu

2011-01-01

478

Cyber Threat Trees for Large System Threat Cataloging and Analysis*  

E-print Network

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

Thornton, Mitchell

479

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

E-print Network

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

New Hampshire, University of

480

The Trade-offs of Multicast Trees and Algorithms  

Microsoft Academic Search

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

Liming Wei; Deborah Estrin

1995-01-01

481

Faster Steiner Tree Computation in Polynomial-Space  

E-print Network

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

Kratsch, Dieter

482

Carbon dynamics in trees: feast or famine?  

PubMed

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

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

2012-06-01

483

Trees from trees: construction of phylogenetic supertrees using clann.  

PubMed

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

Creevey, Christopher J; McInerney, James O

2009-01-01

484

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

PubMed Central

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

2008-01-01

485

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...

486

LIABILITY FOR DAMAGE CAUSED BY HAZARDOUS TREES  

Microsoft Academic Search

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

L. M. Anderson; Thomas A. Eaton

1986-01-01

487

Reliability evaluation based on fuzzy fault tree  

Microsoft Academic Search

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

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

2010-01-01

488

Simaroubaceae (Quassia family) Tree-of-heaven  

E-print Network

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

489

Intraspecific gene genealogies: trees grafting into networks  

Microsoft Academic Search

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

David Posada; Keith A. Crandall

2001-01-01

490

The Arctic Tree Line and Climate Change  

E-print Network

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