WorldWideScience

Sample records for christmas trees

  1. Christmas Tree Category Manual.

    Science.gov (United States)

    Bowman, James S.; Turmel, Jon P.

    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…

  2. Leader growth in Nordman fir christmas trees

    DEFF Research Database (Denmark)

    Christensen, Claus Jerram; Pedersen, Lars Bo

    Leader Griowth in Nordman fir Christmas trees: Growth visualization and effects of fertilization, irrigation and drought......Leader Griowth in Nordman fir Christmas trees: Growth visualization and effects of fertilization, irrigation and drought...

  3. 7 CFR 1437.306 - Christmas tree crops.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Christmas tree crops. 1437.306 Section 1437.306... Determining Coverage Using Value § 1437.306 Christmas tree crops. (a) A Christmas tree is a value loss crop... commercial use as a Christmas tree, and only if other requirements of this section are met. (b) The unit...

  4. 29 CFR 780.208 - Forest and Christmas tree activities.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Forest and Christmas tree activities. 780.208 Section 780... Christmas tree activities. Operations in a forest tree nursery such as seeding new beds and growing and transplanting forest seedlings are not farming operations. The planting, tending, and cutting of Christmas...

  5. 16 CFR 501.2 - Christmas tree ornaments.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Christmas tree ornaments. 501.2 Section 501.2 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENT OF GENERAL POLICY OR... PROHIBITIONS UNDER PART 500 § 501.2 Christmas tree ornaments. Christmas tree ornaments packaged and labeled...

  6. Christmas

    Institute of Scientific and Technical Information of China (English)

    许涛

    2004-01-01

    DoyouknowwhatChristmasmeans?ChristmasDayisthebirthdayofJesusChrist.WhenChristwasbornnearlytwothousandyearsago,manypeople,richandpoor,gavehimpresents.Sotoday,peoplestilldothesamethingtoeachother.ChristmasEveisthenightbeforeDecember25.ChildrenarehappieronChristmasEve.Theyputtheirstockingsattheendoftheirbedsbeforetheygotosleep.TheywantFatherChristmastogivethemsomepresents.TheirparentstellthemFatherChristmasisaverykind-heartedman.HecomesonChristmasEvedownthechimneyintothefireplaceandbringsthemalotofpresents.Chr...

  7. 29 CFR 780.216 - Nursery activities generally and Christmas tree production.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Nursery activities generally and Christmas tree production... Nursery activities generally and Christmas tree production. (a) The employees of a nursery who are engaged... Christmas trees are considered to be agricultural or horticultural commodities. Employees engaged in...

  8. 75 FR 68529 - Proposed Christmas Tree Promotion, Research, and Information Order; Referendum Procedures

    Science.gov (United States)

    2010-11-08

    ... Agricultural Marketing Service 7 CFR Part 1214 RIN 0581-AD00 Proposed Christmas Tree Promotion, Research, and... determine whether the issuance or continuation of the proposed Christmas Promotion, Research, and Information Order (Proposed Order) is favored by domestic producers and importers of Christmas trees....

  9. Leakage Test Criteria for Subsea Christmas Tree Valves

    OpenAIRE

    Alstad, Charlotte

    2011-01-01

    This Master`s Thesis deal with integrity and barrier philosophy. A special focus has been on internal leakage through barrier elements. There is an increasing discussion about what a primary and secondary barrier is, how many barriers there should be, their permitted internal leakage acceptance criteria and their integrity. Subsea Christmas tree (XMT) is considered as a pressure barrier element in subsea production systems. Rules and regulations require frequent leakage testing of subsea XMT ...

  10. Seasonal fluctuation in concentrations and content of sugar, starch and nutrient in nordmanns fir (Abies nordmannia) Christmas tree

    DEFF Research Database (Denmark)

    Pedersen, Lars Bo; Christensen, Claus Jerram

    Seasonal fluctuation in concentrations and content of sugar, starch and nutrient in nordmanns fir (Abies nordmannia) Christmas tree......Seasonal fluctuation in concentrations and content of sugar, starch and nutrient in nordmanns fir (Abies nordmannia) Christmas tree...

  11. 76 FR 9695 - Proposed Christmas Tree Promotion, Research, and Information Order; Extension of Comment Period...

    Science.gov (United States)

    2011-02-22

    ..., and published in the Federal Register on November 8, 2010, (75 FR 68512). That rule proposed the... Agricultural Marketing Service 7 CFR Part 1214 RIN 0581-AD00 Proposed Christmas Tree Promotion, Research, and... information program for fresh cut Christmas trees is reopened and extended. The comment period is also...

  12. 75 FR 68512 - Proposed Christmas Tree Promotion, Research, and Information Order

    Science.gov (United States)

    2010-11-08

    ... image of Christmas trees. Section 1214.11 would define the term ``marketing'' to mean the sale or other... Agricultural Marketing Service 7 CFR Part 1214 RIN 0581-AD00 Proposed Christmas Tree Promotion, Research, and Information Order AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule with request...

  13. Christmas cards

    Institute of Scientific and Technical Information of China (English)

    李国勤

    2002-01-01

    Every December,millions of Christmas cards go through the post offices.There're pictures of stars,snow or Christmas tree on the cards. In these days it's hard to think of a Christmas without cards,yet 150 years ago there were no cards at all.Here's jus! one story about the Christmas cards.Some boys of those days who were at boarding school had to write a special piece of English at Christmas time。

  14. CONSUMER'S SPECIE KNOWLEDGE AND THE VALUES OF NATURAL CHRISTMAS TREE CHARACTERISTICS

    OpenAIRE

    Davis, George C.

    1993-01-01

    Consumers' willingness to pay for natural Christmas tree characteristics are estimated. Differences in willingness to pay for characteristics by specie knowledge and lack of specie knowledge are tested. Differences in willingness to pay for characteristics by specie are also tested. The results suggests that willingness to pay measures differ by these separations of the sample and, ceteris paribus, sellers of natural Christmas trees could benefit by altering characteristics in accordance with...

  15. Axial segregation of horizontally vibrated binary granular mixtures in an offset-Christmas tree channel

    Science.gov (United States)

    Bhateja, Ashish; Sharma, Ishan; Singh, Jayant K.

    2013-06-01

    We investigate segregation in a horizontally vibrated binary granular mixture in a closed offset-Christmas tree channel. The segregation phenomenon occurs in two steps: vertical sorting followed by axial segregation. In the first step, sorting occurs via Brazil-nut effect or reverse Brazil-nut effect depending on the particles' size and density ratios. The two layers thus formed then separate axially towards opposite-ends of the channel with the top layer always moving towards root of the Christmas tree. We discuss the segregation mechanism responsible for axial segregation.

  16. Comparative life cycle assessment (LCA) of artificial vs natural Christmas tree

    Energy Technology Data Exchange (ETDEWEB)

    Couillard, S.; Bage, G.; Trudel, J.S.

    2009-02-15

    This document reported on a study that compared the environmental impacts of a natural versus artificial Christmas tree using life cycle assessment (LCA) methodology. The LCA followed the recognized ISO 14040 and 14044 standards and it was reviewed by an independent third-party of peers. The purpose of the study was to guide the general public in choosing the best type of Christmas tree based on sustainable development and environmental considerations. The modelled natural tree was harvested in a plantation near Montreal, while the artificial tree was manufactured in China and shipped by boat and train to Montreal via Vancouver. Both trees were assumed to be 7 feet high. The lights and decorations were excluded from the analysis. Calculations for the artificial tree were based on a 6-year life span, the average time an artificial tree is kept in North America. The LCA considered the resources extraction and processing of raw materials, the manufacturing processes, transport and distribution, use, reuse and then recycling and disposal at the end of life. The environmental impacts of the natural and artificial trees showed the impacts of each tree for 4 damage categories, namely human health, ecosystem quality, climate change and resources. It was concluded that the natural tree is a better option than the artificial tree, particularly in terms of impacts on climate change and resource depletion. However, the natural tree was found to have important impacts on ecosystem quality. Those who prefer using the artificial tree can reduce their impacts on all categories by increasing the life span of their tree to over 20 years. 6 figs.

  17.   Biotechnology in Danish forestry - Christmas trees and Biofuels

    DEFF Research Database (Denmark)

    Find, Jens

    Clonal propagation of elite trees by somatic embryogenesis (SE) can shorten periods needed for breeding of trees, and can ensure a stable production of high quality plants for the forestry sector. SE has special interest as a breeding tool, because it for many species is the preferred basis...

  18. Lighting up the Christmas tree: high-intensity laser interactions with a nano-structured target

    CERN Document Server

    Gonoskov, A; Ilderton, A; Mackenroth, F; Marklund, M

    2014-01-01

    We perform a numerical study of the interaction of a high-intensity laser pulse with a nano-structured target. In particular, we study a target where the nano-structuring increases the absorption rate as compared to the flat target case. The transport of electrons within the target, and in particular in the nano-structure, is analysed. It is shown that it is indeed possible, using a terawatt class laser, to light up a nano-scale Christmas tree. Due to the form of the tree we achieve very strong edge fields, in particular at the top where the star is located. Such edge fields, as here located at ion rich spots, makes strong acceleration gradients possible. It also results in a nice, warm glow suitable for the holiday season.

  19. Soil Carbon Storage in Christmas Tree Farms: Maximizing Ecosystem Management and Sustainability for Carbon Sequestration

    Science.gov (United States)

    Chapman, S. K.; Shaw, R.; Langley, A.

    2008-12-01

    Management of agroecosystems for the purpose of manipulating soil carbon stocks could be a viable approach for countering rising atmospheric carbon dioxide concentrations, while maximizing sustainability of the agroforestry industry. We investigated the carbon storage potential of Christmas tree farms in the southern Appalachian mountains as a potential model for the impacts of land management on soil carbon. We quantified soil carbon stocks across a gradient of cultivation duration and herbicide management. We compared soil carbon in farms to that in adjacent pastures and native forests that represent a control group to account for variability in other soil-forming factors. We partitioned tree farm soil carbon into fractions delineated by stability, an important determinant of long-term sequestration potential. Soil carbon stocks in the intermediate pool are significantly greater in the tree farms under cultivation for longer periods of time than in the younger tree farms. This pool can be quite large, yet has the ability to repond to biological environmental changes on the centennial time scale. Pasture soil carbon was significantly greater than both forest and tree farm soil carbon, which were not different from each other. These data can help inform land management and soil carbon sequestration strategies.

  20. Experimental study on determining factors of canopy interception using artificial Christmas trees

    Science.gov (United States)

    Murakami, Shigeki; Toba, Tae

    2013-04-01

    Evaporation of canopy interception (CI) is a major component of water balance in forested areas. Theoretically, the evaporation amount is dependent on the tree height, i.e. aerodynamic roughness. Nevertheless, the theory does not always explain the observed results and the observational fact that CI during rainfall is proportional to the rainfall intensity makes the problem paradoxical (Murakami, 2006). The objective of this study is to try to find the determining factors of CI in terms of the stand structure using artificial Christmas trees that is easy to modify the height and tree density. Two kinds of artificial Christmas trees were used: a) 65 cm high with the maximum canopy diameter of 30 cm, and b) 150 cm high with the greatest canopy diameter of 75 cm. We set those trees on three trays and left them outside to measure CI using natural rainfall. Artificial trees a) were set on Tray #1 and #2 measuring 178-cm-square. Artificial trees b) were fixed on Tray #3 with a size of 360-cm-square. Tray #1 was a control and the stand structure was unchanged throughout the experiment, i.e. tree height was 65 cm with 41 stems on the tray. Three experimental runs were conducted; Run #1 and #2 were to compare the effect of stem length (tree height) on CI. Run #3 was to evaluate the effect of thinning. The initial number of trees on each tray was 41 (Run #1 and #2), and it was reduced to 25 after thinning for Tray #2 and #3 (Run #3). At Run #1 tree heights of Tray #2 and #3 were 90 cm and 150 cm (original), respectively, and at Run #2 and #3 they were 120 cm and 240 cm, respectively. In Tray #1 canopy interception rate (IR, the ratio of CI to gross rainfall) was constant (12.1% to 13.3%). IR increased with tree height for each tree, i.e. a) and b). In Tray #2, i.e. tree a), IR increased from 19.7% to 22.8% after thinning, while in Tray #3, i.e. tree b), it diminished from 20.0% to 13.8%. Preliminary analysis showed that hourly CI is clearly proportional to hourly rainfall

  1. Christmas tree worms of Indo-Pacific coral reefs: untangling the Spirobranchus corniculatus (Grube, 1862) complex

    Science.gov (United States)

    Willette, Demian A.; Iñiguez, Abril R.; Kupriyanova, Elena K.; Starger, Craig J.; Varman, Tristan; Toha, Abdul Hamid; Maralit, Benedict A.; Barber, Paul H.

    2015-09-01

    Christmas tree worm is the common name of a group of colorful serpulid polychaetes from the genus Spirobranchus that are symbionts of hermatypic corals. As is increasingly common with reef-associated organisms, Spirobranchus is arranged as a complex of species with overlapping geographic ranges. Current species delimitations based largely on opercular morphology are problematic because of high intraspecific variation. Here, a multi-gene phylogeny of the Spirobranchus corniculatus complex, which tentatively includes S. corniculatus, S. cruciger, and S. gaymardi, sampled from the Coral Triangle, Australia, and Fiji, was reconstructed to test whether the complex includes three genetically distinct lineages identifiable by their opercula. Maximum-likelihood analyses of nuclear and mitochondrial markers revealed a single, monophyletic clade for the S. corniculatus complex. Furthermore, the genetic and morphological variation observed is not geographically based, indicating that the former S. corniculatus complex of three morphospecies is a single, morphologically variable species across the Central Indo-Pacific. Resolving the taxonomy of S. corniculatus presents novel opportunities to utilize this tentative bio-indicator species for monitoring reef health.

  2. Analysis of the Discourse of Power in Etel Adnan's Play Like A Christmas Tree

    Directory of Open Access Journals (Sweden)

    Hossam Mahmoud Alashqar

    2015-10-01

    Full Text Available This paper seeks to investigate the sources of power in the discourse of an Arab-American writer, Etel Adnan's one act play, Like a Christmas Tree. The play represents a heated argument between two figures who stand for two different ideologies and who fall within the frame of 'binary opposition', transcultural misunderstanding, and colonial hegemony versus native resistance. Supposedly, an American Journalist, Jim, is expected to dominate the discourse by force of his cultural and professional background, but sarcastically enough, the Iraqi butcher, Badr is the part who represents power and domination throughout the play. The current paper depends on more than one tool of analysis: Norman Fairclough's (2001 and Foucault's(2004 concepts of power and discourse, Grice's theory of 'cooperative principles'(1989, Brown and Gilman's study of 'address forms' (1972, and Georgia Green's contribution in the process of 'turn-taking' (1989.The study celebrates an analysis of data which uncovers the power of discourse in the exchanges of both characters and sheds light on the identity of both of them in an attempt to affirm that 'power' is not necessarily on the side of the stronger.Keywords: discourse, power, address forms, turn-taking, interruption, topic control     

  3. Long-Term Soil Productivity in Christmas Tree Farms of Oregon and Washington: A Comparative Analysis between First- and Multi-Rotation Plantations

    Directory of Open Access Journals (Sweden)

    Jeff Hatten

    2014-10-01

    Full Text Available Christmas tree production removes organic matter and associated nutrients from a site and can change soil physical properties, reduce mycorrhizal populations, and result in pesticide over-use/accumulation. These impacts have been implicated in potential field productivity declines. Assessing Christmas tree productivity is complicated by genetics, management, and market forces. We approached the perceived or possible productivity decline by examining soil properties on 22 pairs of sites. Each pair was comprised of an early rotation and late rotation plot with 1 and 3 or more rotations of Christmas trees, respectively. All sites were located on commercial Christmas tree plantations from the major production areas in Washington and Oregon. Chemical properties assessed to 45cm included pH, total C and N, and extractable P, K, Ca, and Mg. Soil physical properties assessed included aggregate stability and soil resistance. In general, we found little impact on soil resources that would impact long term production of Christmas trees. These impacts may have been mitigated by farmers following extension service recommendations. Nitrogen, K, and Ca appeared to be primarily affected by harvesting, but replacement by fertilizer application was probably adequate.

  4. Use of shaking treatments and pre-harvest sprays of pyrethroid insecticides to reduce risk of yellowjackets and other insects on Christmas trees imported into Hawaii

    Science.gov (United States)

    Insects are commonly found by Hawaii’s quarantine inspectors on Christmas trees imported from the Pacific Northwest. To reduce the risk of importing yellowjacket (Vespula spp.) queens and other insects, an inspection and tree shaking certification program was begun in 1990. From 1993 to 2006, the an...

  5. Leaching versus input of nitrogen, potassium and magnesium in different fertilizer regimens in Christmas tree stands of Abies nordmanniana in Denmark

    DEFF Research Database (Denmark)

    Pedersen, Lars Bo; Christensen, Claus Jerram; Ingerslev, Morten

    2006-01-01

    The effects of nitrogen (N), potassium (K) and magnesium (Mg) fertilization and deposition on nutrient leaching were assessed in four Danish Nordmarm fir Christmas tree stands on former arable land. NPK 23-3-7 fertilizer type was applied in doses between 0 and 1200 kg ha(-1) year(-1). Deposition...

  6. Christmas party

    CERN Multimedia

    Staff Association

    2011-01-01

    The Christmas party organized by the Staff Association took place on Saturday 3 December. 200 children from 5 to 7 years old attended a magic show which filled them with wonder. Then they were served a snack in the Novae restaurant. Finally, just before their parents came to pick them up, Father Christmas gave them a present. The Staff Association wishes you a Merry Christmas and a Happy New Year!

  7. The sweet Christmas rash (case series)

    DEFF Research Database (Denmark)

    Gyldenløve, Mette; Nepper-Christensen, Steen; Thyssen, Jacob P;

    2013-01-01

    Christmas tree hypersensitivity is a rare condition, which has so far obtained scarce attention in the medical literature. We present two clinical cases of hypersensitivity associated with Christmas tree exposure, a 51-year-old woman with allergic contact dermatitis and a 41-year-old man...... with allergic rhinitis. The female patient had a positive patch test reaction to colophony, and the male patient had a positive skin prick test reaction to alternaria mould. Both were successfully advised to avoid prolonged exposure to Christmas trees and buy artificial trees for Christmas....

  8. Christmas Blessings

    Institute of Scientific and Technical Information of China (English)

    小溪

    2005-01-01

    Merry Christmas and Best Wishes for a Happy New Year ! Beautiful dream comes true .Bring you good wishes of happiness this Christmas and on the coming year . Greeting you warmly with a wish that ’s sincere for a healthy happy and wonderful day . Have a heartwarming holiday! Warmest wishes for a very merry Christmas ! Have a Wonderful Holiday Season ! Hope your holiday is great and your New Year a prosperous one . In our hearts , we ’llalways be near merry Christmas ! Joy to the world. Wishing you an extreme...

  9. Christmas Cards

    Institute of Scientific and Technical Information of China (English)

    许涛

    2004-01-01

    ItwastwoweeksbeforeChristmas,andMrs.Smithwasverybusy.SheboughtalotofChristmascardsandputthemonthetable.Theywereforherfriendsandforherhusband'sfriends.Whenherhusbandcamebackfromwork,shesaidtohim,“herearetheChristmascardsforourfriends,andherearesomestamps,apenandourbookofaddresses.WillyouplesaewritethecardswhileI'mcookingthedinner?”Mr.Smithdidn'tsayanything,buthewenttoanotherroom.Mrs.Smithwasveryangrywithhim,butsoonMr.SmithcamebackwithaboxofChristmascards.Allofthemhadaddressesandstampsonthemalready.“Thesewere...

  10. Christmas Chill

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    For numerous Chinese exporters, this year’s Christmas season means more despair than cheerWandering through his toy fac- tory in Shenzhen, Guangdong Province, Lin Zhanpeng barks orders as a few workers move around machines

  11. Christmas Day

    Institute of Scientific and Technical Information of China (English)

    任民

    2005-01-01

    @@ Ah! Christmas morning!Children like to wake up early while it's still dark and sneak into(鬼鬼祟祟地走进……)the living room to check the presents--find any with their name on it, shake them to guess what's inside,and then maybe they'll go back to bed and pretend (假装)they are still asleep when their parents come to wake them with a "Merry Christmas!"

  12. Christmas Day

    Institute of Scientific and Technical Information of China (English)

    顾晓玲

    2008-01-01

    提起圣诞节,大家一定会想到圣诞老人、圣诞礼物。那么圣诞节是怎么由来的呢?来,一起走进下文!Christmas,originating as a contraction of "Christ’s mass", is an annual holiday celebrated on December 25 to mark and honor the birth of Jesus Christ, although the date is not considered to be the actual birthday of Jesus. Not

  13. Changes of Christmas

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-lin

    2006-01-01

    Compared with the lavish celebration in the past, Christmas nowadays loses some old significance of the traditions. Christmas is not as pure a religious holiday as the past. With the fast development of the economy, Christmas becomes extravagant.

  14. 海上平台采油树辅助液压系统研究%Study of the christmas tree auxiliary hydraulic control system on offshore platform

    Institute of Scientific and Technical Information of China (English)

    陈肇日; 苟潮洋

    2011-01-01

    海上平台采油树钢丝作业过程中,为了防止采油树液控主阀意外关闭而切断钢丝,目前采用的是给液控主阀戴帽的方法,此方法存在很大的安全隐患.设计了采油树辅助液压系统,在钢丝作业过程中采用双液压源控制采油树液控主阀,提高了钢丝作业过程的安全性.%At present, the valve cap is used to prevent the wire line from cut off due to unexpected close of hydraulic master valve during the christ-mas tree wire line operation on offshore platform. This method has the potential safety hazard. Therefore,a set of auxiliary hydraulic control system has been designed to keep the master valve o-pening by using double hydraulic source during the wire line operation, so as to improve the safety of wire line operation.

  15. Survival, frost susceptibility, growth, and disease resistance of corkbark and subalpine fir grown for landscape and Christmas trees

    Science.gov (United States)

    Trees from six corkbark fir (Abies lasiocarpa var. arizonica) and 10 subalpine fir (A. lasiocarpa var. lasiocarpa) seed sources were grown at the University of Idaho Sandpoint Research and Extension Center (SREC) and two commercial nurseries in Idaho and Oregon. Post transplant mortality was highest...

  16. Seed Source Significantly Influences Growth Rates and Disease Resistance of Abies Lasiocarpa Grown for Ornamental Nursery Stock and Christmas Trees

    Science.gov (United States)

    Trees from six corkbark fir (Abies lasiocarpa var. arizonica) and 10 subalpine fir (Abies lasiocarpa var. lasiocarpa) seed sources were grown at the University of Idaho (SREC) and three commercial nurseries in northern Idaho and northeastern Oregon. Post transplant mortality was highest during the f...

  17. A Christmas Carol

    NARCIS (Netherlands)

    Dickens, Charles

    2005-01-01

    A Christmas Carol was an overnight success when first published in 1843, and was followed by two further Christmas books, The Chimes and The Cricket on the Hearth, also included in this volume. But A Christmas Carols Ebenezer Scooge is one of Dickenss most unforgettable characters, a miserable skinf

  18. Response Spectrum Analysis of Pile of Christmas Tree by ANSYS Workbench%基于 ANSYS Workbench 的采油树管道响应谱分析

    Institute of Scientific and Technical Information of China (English)

    尹汉军; 刘昌领; 姜瑛; 何宁强

    2015-01-01

    针对采油树管道计算其固有频率和模态振型,在此基础上分析其在波浪谱曲线激励下的振动情况。结果表明:在输油管道和转换通道末端是振动幅度最大的部位,主振方向为 x 方向;横向波浪谱对结构振动的影响远大于纵向波浪谱;生产主阀处的应力最大,输油管道上端弯头处的应变最大。通过增大管道直径和壁厚、减小弯头数量、增加管道支吊架等措施提高管道刚度,以达到减小管道振动的目的。%For pipelines of Christmas tree,the natural frequencies and modal shapes of pipelines were calculated,then,the response spectrum by the wave was calculated based on the result of the modal analysis.And the conclusion shows that the largest vibration amplitude happens on the end of pipeline,the main vibration direction is x direction,and the influence of transverse wave spec-trum is much greater than that of longitudinal wave,besides,the maximum stress occurs on the main valve,and the maximum strain happens on the upper elbow of the oil pipelines.The vibration can be reduced by enhancing the stiffness of the pipelines based on increasing the diameter and wall thickness of the pipes,reducing the number of elbows and installing pipe hangers.

  19. Intelligence Study on Subsea Christmas Tree Industry Based on Patent Analysis%基于专利分析的深海水下采油树产业情报研究

    Institute of Scientific and Technical Information of China (English)

    张善杰; 陆亦恺; 陈伟炯; 刘晓琴

    2014-01-01

    During recent years, the global oil and gas resources exploration has been extended to deep seas. The subsea christmas tree, as the key equipment in extracting deepwater oil, has been widely used by oil-gas developers, however, the core technologies have been con-trolled by several foreign manufacturers. Based on patent analysis, this paper studies the patent amount, development trend, technology portfolio, area distribution, and the competition assignee of subsea christmas tree. In the end, proposals and measures are put forward to promote the R&D and development of subsea christmas tree industry in China.%随着海洋油气资源开发逐步走向深海,全球主要深水海工装备均采用水下采油树技术作为深水采油的核心解决方案,但水下采油树的关键技术却被国外少数厂商所垄断。基于专利分析方法,通过对水下采油树技术的专利数量规模、发展趋势、技术领域、专利地域分布、竞争机构进行数据挖掘和深度分析,最后提出促进我国水下采油树技术研发和产业发展的策略和建议。

  20. Kosher and the Christmas Tree

    DEFF Research Database (Denmark)

    Dencik, Lars

    2009-01-01

    The article present results from a questionnaire investigation with members of the Jewish communities in Sweden, Finland and Norway.......The article present results from a questionnaire investigation with members of the Jewish communities in Sweden, Finland and Norway....

  1. The christmas star

    Institute of Scientific and Technical Information of China (English)

    孙飞; 李晓芸

    2004-01-01

    This was my grandmother's first Christmas without Grandfather, and we had promised him before he passed away (逝世) that we would make this her best Christmas ever. When my mom, dad, three sisters and I arrived at her litde house in the Blue Ridge Mountains in North

  2. Legend of the Christmas spider%关于圣诞的美丽传说

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ If you've ever gazed at the beautiful tinsel sparkling on your Christmas Tree and wondered who came up with idea of decorating the tree in this way,wonder no longer.According to German legend,it signifies a Christmas miracle from many years ago.

  3. Freezing Warm Christmas

    Institute of Scientific and Technical Information of China (English)

    NGUYEN; THI; CAM; PHUNG

    2007-01-01

    A lot of Beijing expats carp at Christmas here because of celebra- tion allegedly without regard for its true spirit. Not me. I’m from Ho Chi Minh City,Viet Nam,where Christmas is more like Mardi Gras than a celebration of Jesus Christ’s birth. Granted,on December 25,people gather in droves at"one particular church"in Saigon,as we still like to say.But what happens there is anything but holy. Mayhem,if not murder,ensues.

  4. Numerical Study on Heat Transfer and Thermal Insulation of Subsea Christmas Tree Connectors%水下采油树跨接管接头的传热计算与保温分析

    Institute of Scientific and Technical Information of China (English)

    丁矿; 朱宏武; 郝建生; 张建华

    2012-01-01

    The subsea christmas tree and well jumper are connected by special subsea connectors and collet connector is commonly used. The connector installed underwater will induce continuous heat transferring to ambient cold seawater and cause excessive temperature drop under shutdown condition. Relevant temperature distribution and heat transfer problems must be evaluated so as to further increase the flow security of the subsea christmas tree. Based on the requirment of subsea hydrocarbon development, a coupled fluid-solid numerical method was adopted to analyze the heat transfer and fluid flow of the collet connector without thermal insulation treatment. In addition,this paper completed the numerical study on heat transfer of the collet connector covered by an insulation cavity(doghouse) and the inner flow field simulation of the collet connector based on the consideration of variable properties of fluids. The results show that local supercooled spot would be present in the connector without any insulation measures and the doghouse could greatly improve the effect of thermal preservation on collet connectors which satisfy the basic principle of eight hours' thermal insulation for subsea christmas trees. The method of coupling heat transfer of subsea collet connector is feasible in theory and reliable in calculation results.%水下采油树和跨接管之间需要专用接头进行连接,其中以套筒式接头最为常见.在水下进行接头安装时,持续的热量交换会导致接头在停机条件下持续降温,因此必须预先评估相关的温度分布和热量传递问题,提高水下采油树系统的流动安全水平.根据水下油气开发的要求,结合已有经验,在水下采油树套筒式跨接管接头结构设计的基础上,采用耦合传热的数值模拟方法,对未进行保温的套筒式接头进行了模拟分析,并完成了包含保温腔的套筒式接头的传热计算;最后基于变物性的分析方法,对含有保温腔的套筒

  5. Restaurants closed over Christmas

    CERN Multimedia

    2011-01-01

    The restaurants will be closed during the Christmas holiday period : please note that all three CERN Restaurants will be closed from 5 p.m. on Wednesday, 21 December until Wednesday, 4 January inclusive. The Restaurants will reopen on Thursday, 5 January 2012.

  6. Christmas Time and Cultural Traditions

    Institute of Scientific and Technical Information of China (English)

    周顺伍

    2006-01-01

    Christmas is a holiday that is celebrated around the world. Many of the old customs are still carried out in America. Swedish families start to celebrate their Christmas on December 13th, St. Lucia’ s Day. The eldest daughter wears a white dress and a wreath(花冠) with seven lighted candles on her head. She gives the family coffee in bed.

  7. Suggestions for Christmas gifts.

    CERN Multimedia

    Connie Potter; Markus Nordberg

    Have you been working long hours lately? Stuck in meetings too long to make it in time before the shops close? No need to worry. The ATLAS secretariat has plenty of items that will make great Christmas gifts for friends and family. Here are some of the items in stock. Note that you can negotiate a good price for bulk order. ATLAS caps (new item), 12 chf ATLAS t-shirts designed by Alan Alda, 20 chf ATLAS fleece jackets in several sizes and colors, 30 chf grey or dark blue in men's sizes pale blue for women's sizes (limited quantity) red for children (limited quantity) ATLAS puzzles with 500 pieces made by the Ravensburger company 15 chf for 1 box (price is less when purchasing more boxes) 50 chf for 5 boxes or more can also be purchased in boxes of 24, ready to ship to your institute ATLAS 3-D viewers, 5 chf ATLAS DVD, 5 chf CERN playing cards, 2 chf Make sure to get several boxes of the ATLAS puzzle for Christmas gifts. Offer hours of entertainement to friends and family! We tak...

  8. Christmas Island birds returning

    Science.gov (United States)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  9. Mystery photos: Christmas edition

    CERN Multimedia

    Alex Brown, Jens Vigen, Rosaria Marraffino

    2014-01-01

    Paraphrasing George R.R. Martin's novel Game of Thrones’ most famous quote: “Christmas is coming”. According to tradition, we’ve themed our last issue of the year to share the spirit of the festivities with our readers. We’ve collected some pictures of snowy scenes and Christmas parties at CERN from our archives.   Identifying pictures and albums in the CERN photo archive continues apace and we still need your help. However, in keeping with the holiday spirit, we’ve set you some Christmassy challenges. Were you at any of the events shown below, or do you recognise anyone in the pictures? Get in touch by email: photo.archive@cern.ch or use the “suggest a caption” link on each picture’s page. So far, more than 33,000 pictures have been uploaded, with nearly 1,000 old album records inspected and about 150 new ones created. We’ve had contact from an ever-increasing number of reti...

  10. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    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…

  11. CERN Shop Christmas Sale

    CERN Multimedia

    Visits & Exhibition Service/ETT-VE

    2001-01-01

    11-13.12.2001 Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 11 to Thursday 13 December from 10.30 to 16.00. CERN Calendar 10.- CERN Sweat-shirts(M, L, XL) 30.- CERN T-shirt (M, L, XL) 20.- New CERN silk tie (2 colours) 35.- Fancy silk tie (blue, bordeau) 25.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- CERN watch 25.- CERN baseball cap 15.- CERN briefcase 15.- Book 'Antimatter' (English) 35.- Book 'How the web was born' (English) 25.- The Search for Infinity (French, Italian, English, German) 40.-   If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.30 hrs.

  12. A working Christmas

    CERN Document Server

    2005-01-01

    The repair of faulty elements in the cryogenic distribution line is making great progress in building 927 at CERN. While many of us were relaxing over the two-week Christmas break, the team repairing elements of the LHC cryogenic distribution line - or QRL - continued working, keeping the repair schedule on course for completion by the end of March. Pipe elements with faulty sliding tables are being repaired by the ICS consortium, in charge of installing the cryo-magnets in their cryostats. This team began repairs at the beginning of November, fixing 10 elements a week (See Bulletin 42/2004 from 11 October 2004). However, during the five-week winter shutdown of the magnet test facility they are being assisted by 20 personnel who normally work on magnet testing. With the extra help a repair rate of five pipe elements a day has been reached - 25 elements a week - thanks to the remarkable effort of the ICS personnel led by Patrick Voisin, the DBS personnel assuring the transport and handling of the elements, an...

  13. CERN SHOP CHRISTMAS SALE

    CERN Multimedia

    Visits & Exhibition Service

    2000-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 12 to Thursday 14 December from 10.00 to 16.00.   Sweat-shirt col zippé, grey, blue, black (M, L, XL) 30.- Sweat-shirt col polo, grey, collar blue (M, L, XL) 30.- T-shirt, black, (M, L, XL) 15.- WWW T-shirt, white, bordeau (M, L, XL) 15.- CERN silk tie (3 colours) 33.- Fancy silk tie (blue, bordeau 25.- Silk scarf (blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- New model of CERN watch 25.- New CERN baseball cap 10.- Antimatter (English/anglais) 30.- The Search for Infinity (French, Italian, English,) 35.- Auf der Suche nach dem Unendlichen 45.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.30 hrs (Shop will be closed at 12.00 on 22.12.).

  14. Christmas Morning, Breakfast, Horace Pippin

    Science.gov (United States)

    Braunlin-Jones, Heather

    2004-01-01

    This brief article describes the life and the art of Horace Pippin. It focuses on one work called "Christmas Morning, Breakfast" that is part of a series of works based on Pippin's childhood memories. The painting depicts a very modest room, including exposed wallboards where chunks of plaster have fallen off. The room is very tidy, but rather…

  15. A silicon tracker for Christmas

    CERN Multimedia

    2008-01-01

    The CMS experiment installed the world’s largest silicon tracker just before Christmas. Marcello Mannelli: physicist and deputy CMS project leader, and Alan Honma, physicist, compare two generations of tracker: OPAL for the LEP (at the front) and CMS for the LHC (behind). There is quite a difference between 1m2 and 205m2.. CMS received an early Christmas present on 18 December when the silicon tracker was installed in the heart of the CMS magnet. The CMS tracker team couldn’t have hoped for a better present. Carefully wrapped in shiny plastic, the world’s largest silicon tracker arrived at Cessy ready for installation inside the CMS magnet on 18 December. This rounded off the year for CMS with a major event, the crowning touch to ten years of work on the project by over five hundred scientists and engineers. "Building a scientific instrument of this size and complexity is a huge technical a...

  16. A Christmas Book from 1875

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2009-01-01

    This is a story about a book that I found in my collection, its author, and the boy who owned it. The book is "The Boy's Playbook of Science", first published in 1860 by John Henry Pepper (1821-1900). On the flyleaf is written "Arthur G. Webster; Christmas/75; from Mama." Arthur Gordon Webster (1863-1923) was one of the founders of the American…

  17. Major burn injuries associated with Christmas celebrations: a 41-year experience from Switzerland.

    Science.gov (United States)

    Rohrer-Mirtschink, S; Forster, N; Giovanoli, P; Guggenheim, M

    2015-03-31

    In Switzerland it is customary to light candles on Christmas trees and advent wreaths. This tradition leads to an increased risk of home fires. We reviewed the records of patients who sustained burn injuries from a lit Christmas tree or advent wreath during the Christmas holidays between January 1971 and January 2012. We treated 28 patients and observed 4 fatalities (mortality rate: 14%). 61% of the patients were male, 39% were female. The mean abbreviated burn severity index (ABSI) was 6.5 points in the group of the survivors and 10.8 points in the group of the non-survivors. The mean total body surface area burned (TBSA) for survivors was 18.9%, with 14.1% having full thickness burns; for the non-survivors the mean TBSA was 45.2%, with 38% having full thickness burns. The Mann-Whitney U-test showed a significant difference between the survivors and the fatalities concerning the mean total and full thickness burned body surface area (p value 0.009 and 0.012). More than sixty percent of the fires occurred in January and the most severe accidents were seen after January 4th. Despite Christmas decoration-associated fires being relatively uncommon, they tend to cause more serious injuries than regular household fires. We recommend that in countries where it is customary to set up flammable Christmas decorations, state-issued information pamphlets with instructions on fire safety conduct should be distributed.

  18. Christmas Card Arrives 93 Years Late

    Institute of Scientific and Technical Information of China (English)

    马加芬

    2008-01-01

    A postcard featuring a color drawing of Santa Claus and a young girl was mailed in 1914, but its jour- ney was slower than Christmas. It just arrived in northwest Kansas. The Christmas card was dated Dec. 23, 1914, and mailed to Ethel Martin of Oberlin, apparently from her cousins in Alma, Neb.

  19. A Report on A Christmas Carol

    Institute of Scientific and Technical Information of China (English)

    周志聪

    2010-01-01

    @@ Charles Dickens is generally considered the greatest English novelist of the Victorian period,as well as a vigorous social campaigner.His works are characterized by attacks on social evils,injustice and hypocrisy,and among which there is one that Dickens called his "little Christmas Book",that is A Christmas Carol.

  20. I Like Christmas Day Best

    Institute of Scientific and Technical Information of China (English)

    文胜

    2009-01-01

    同学们,任何一个国家都有一些反映本国特色的传统节日。在我国,有春节——Spring Festival,端午节——Dragon Boat Festival、中秋节——Mid-Autumn Festival等等。而在西方国家,最为盛大的节日就要数圣诞节——Christmas Day了。

  1. Trees

    Science.gov (United States)

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  2. Christmas

    Institute of Scientific and Technical Information of China (English)

    MichaelProsser

    2004-01-01

    In about 540 AD, a monk named Dionysius the Short tried to establish a calendar starting from the year of Jesus Christ's birth as 1 AD (Anno Domino--in the year of the Lord). However, he miscalucated by about four to seven years too late based on the Roman calendar and the fixation of the stars during the earlier period,

  3. Singing the Praises "A Christmas Carol."

    Science.gov (United States)

    Hearn, Michael Patrick

    1996-01-01

    Contains a "polished" literary essay on Charles Dickens'"A Christmas Carol" that reviews the work's original reception and accounts for its success through a description of its best moments and language. (TB)

  4. Christmas feast in Prévessin

    CERN Multimedia

    2000-01-01

    Restaurant No3 was invaded by a happy bunch of Santa Clauses last Wednesday. It has become a tradition for the restaurant staff to dress up to serve a real Christmas feast. In the menu : Foie gras des Landes, scallops, salmon tartar and of course the traditional Christmas turkey. And a special extra - an aperitif graciously offered by the restaurant. Places were laid for 450 people for this exceptional lunch.

  5. Trees

    CERN Document Server

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V.~Glaser and R.~Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large category of space-times.

  6. 2A Unit9 Merry Christmas

    Institute of Scientific and Technical Information of China (English)

    黄梅

    2014-01-01

    <正>教学内容江苏版牛津英语2A Unit9 Merry Christmas教学目标1.能听懂句子Merry Christmas!并能用Merry Christmas!应答。2.能使用Merry Christmas!向别人祝福圣诞节快乐,语音语调正确。能使用The…is for you.赠送礼物。3.能听懂、会说、初步认读a gift、a bell、a sweet、a chocolate。4.能听懂The bell is for you,并能用Thank you.表示感谢。教学重点1.能听懂句子Merry Christmas!并能用Merry Christmas!应答。2.能听懂、会说、初步认读a gift、a bell、a sweet、a chocolate。3.能使用The…is for you.赠送礼物。教学难点能使用The…is for you.赠送礼物,并能用Thank you.表示感谢。

  7. The Audubon Christmas Bird Count: A Valuable Teaching Resource

    Science.gov (United States)

    Ferner, John W.

    1977-01-01

    The author explains how he uses the Audubon Christmas Bird Count to teach a laboratory exercise in vertebrate population dynamics. Problems and limitations associated with using these Christmas Counts are also enumerated. Graphs illustrate the material. (MA)

  8. Evidence of a Christmas spirit network in the brain

    DEFF Research Database (Denmark)

    Hougaard, Anders; Lindberg, Ulrich; Arngrim, Nanna;

    2015-01-01

    celebrate Christmas with positive associations compared with scans in a group having no Christmas traditions and neutral associations. These cerebral areas have been associated with spirituality, somatic senses, and recognition of facial emotion among many other functions. CONCLUSIONS: There is a "Christmas......OBJECTIVE: To detect and localise the Christmas spirit in the human brain. DESIGN: Single blinded, cross cultural group study with functional magnetic resonance imaging (fMRI). SETTING: Functional imaging unit and department of clinical physiology, nuclear medicine and PET in Denmark. PARTICIPANTS......: 10 healthy people from the Copenhagen area who routinely celebrate Christmas and 10 healthy people living in the same area who have no Christmas traditions. MAIN OUTCOME MEASURES: Brain activation unique to the group with Christmas traditions during visual stimulation with images with a Christmas...

  9. Growth and flowering of Christmas rose (Helleborus niger L. ?Christmas Carol? influenced by cooling

    Directory of Open Access Journals (Sweden)

    Monika Henschke

    2016-03-01

    Full Text Available Christmas rose (Helleborus niger L. is a perennial, which flower buds are formed in late summer or autumn and it blooms from December to April. A significant impact on the development of flower buds has cooling of plants in the autumn. Due to increasing importance of Christmas rose, especially in the accelerated cultivation for Christmas, it is advisable to investigate the effect of cooling on flowering of the latest of varieties. The aim of the study was to determine the growth and flowering of Christmas rose (Helleborus niger L. ‘Christmas Carol’ under the influence of cooling in a polytunnel or cold storage compared to plants without cooling in the greenhouse. It has been shown that the accelerated cultivation of Christmas rose ‘Christmas Carol’ in pots can be done without cooling and with cooling, but in order to shorten the period of acceleration plants in a greenhouse for 11 days, extended flowering period and to obtain more flowering shoots, the cultivation without cooling is recommended.

  10. Evidence of a Christmas spirit network in the brain

    DEFF Research Database (Denmark)

    Hougaard, Anders; Lindberg, Ulrich; Arngrim, Nanna;

    2015-01-01

    celebrate Christmas with positive associations compared with scans in a group having no Christmas traditions and neutral associations. These cerebral areas have been associated with spirituality, somatic senses, and recognition of facial emotion among many other functions. CONCLUSIONS: There is a "Christmas...

  11. Christmas-candle Senna:An ornamental and pharmaceutical plant

    Science.gov (United States)

    Christmas candle (Senna alata L.) is an underutilized legume. The USDA, ARS, PGRCU curates only 2 accessions of Christmas candle. Christmas candle plants were transplanted from about 21 day-old seedlings with further transplanting to larger pots containing potting soil as the plants grew larger. Ho...

  12. Christmas: to be or not to be

    Institute of Scientific and Technical Information of China (English)

    张欣欣

    2015-01-01

    Influenced by the intercultural communication,every culture in the world has a very close contact with each other in various way.As we all know,now more and more western festivals land in China,especially Christmas,which brings impact on our traditional festivals,and it leads to a controversy.As a result,this paper will objectively analyze reasons why Christmas is so popular in China; then interpret deep effects it brings.At last,some suggestions will be given.

  13. Christmas Celebrations Around the World

    Institute of Scientific and Technical Information of China (English)

    王翔

    2005-01-01

    It is interesting to see how different countries celebrate Christm as. W e asked som e ofour friends to explain whathappens in their countries. This is whatthey told us: France In France, Christm as is always called Noёl. Everyone has a Christm as tree,som etim es decorated in the old way with red ribbons and realwhite wax candles. Fir trees in the garden are often decorated too, with lights on allnight. G erm any Germ ans love to decorate their houses at Christm as. M any houses willhave little wooden fram...

  14. CHRISTMAS – FROM RELIGIOUS TO LAIC. THE STIMULI THAT “SELL” CHRISTMAS

    Directory of Open Access Journals (Sweden)

    Teodora Roman

    2014-06-01

    Full Text Available Romania has been a country with a strong cultural background since ancient times. The Romanian people, born Christian, cherished holy days as part of its daily life, Christmas included. From a religious viewpoint, Christmas is one of the twelve holy days celebrated by the rulers of Byzantine Churches, being considered the third great holy day after Easter and Pentecost. However, in relation to the field of marketing, Christmas is a popular holy day, hence an occasion to increase sales. At the level of financial advantages provided, this holy day is the most important one, not only for retailers, but also for the other categories of merchandisers. There are various ways to celebrate this feast: parties, family gatherings, going to church and gifts. Christmas is a religious feast, supported by some people and rejected by others for having been turned into an occasion to spend money and party, thus ignoring its sacred character. Based on the aspects above as premises, this paper aims at shaping the buyer’s behaviour during Christmas time. Therefore, our aims are the identification of those in-store stimuli that create the atmospherics desired by customers when they take the decision to shop in a Christmas context. Another aim is to shape the buyer’s behaviour in choosing Christmas gifts, considering two variables: gender and age. Last but not least, we aim at highlighting the period in which in-store Christmas stimuli have been perceived, whether this coincides with the one when first gifts are bought or not, which was the average budget allocated or the moment people became aware they had to do the shopping for this holy day. The methodological approach includes both a qualitative approach, by using the structured interview and a quantitative approach by conducting a survey based on the snowball sampling method. The population investigated is aged between 25 and 65, lives in the urban area, is married and it was compulsory for the respondents

  15. CERN Shop - Christmas Sale in Bldg. 33

    CERN Multimedia

    PH Department

    Looking for Christmas present ideas? The CERN Shop will give the CERN card holders a special reduction of 10 % on all CERN Shop articles from Friday 11.12.2009 to Thursday 17.12.2009. Come to visit the CERN Shop at the Reception, Building 33. PH-EDU-PO

  16. CERN Shop - Christmas Sale in Bldg. 33

    CERN Multimedia

    PH Department

    2010-01-01

    Looking for Christmas present ideas? The CERN Shop will give CERN card holders a special reduction of 10 % on all CERN Shop articles from Monday 13.12.2010 to Saturday 18.12.2010. Come and visit the CERN Shop in the Reception Building 33.

  17. Generosity and Hospitality in Christmas Story

    NARCIS (Netherlands)

    T. Laine

    2013-01-01

    This short subject discusses what might be understood as Santa Claus’ essence, which is the logic of and limits to his overarching generosity, as depicted in the film Christmas Story (Wuolijoki, 2007). The plot centres on the orphan Nikolas, who grew up to be Santa Claus. Young Nikolas moves to a ne

  18. The Five Senses of Christmas Chemistry

    Science.gov (United States)

    Jackson, Derek A.; Dicks, Andrew P.

    2012-01-01

    This article describes the organic chemistry of five compounds that are directly associated with the Christmas season. These substances and related materials are presented within the framework of the five senses: silver fulminate (sound), alpha-pinene (sight), sodium acetate (touch), tryptophan (taste), and gingerol (smell). Connections with the…

  19. The geese who flew home for Christmas

    DEFF Research Database (Denmark)

    Henriksen, Jens H

    2013-01-01

    mutation in haemoglobin and cytochrome oxidase, re-location of mitochondria, and extreme shifts in the oxy-haemoglobin dissociation curve due to Bohr- and temperature effects. The second annual migration takes place in late autumn, and the bar-headed geese come home in due time before Christmas....

  20. Christmas Sale on 11 and 12 December

    CERN Multimedia

    DSU Unit

    2008-01-01

    CERN Shop Are you short of ideas for Christmas presents? If so, come and have a look at the stall the CERN shop will be setting up outside Restaurant No. 1 in the Main Building on the Meyrin site on Thursday 11 and Friday 12 December from 10.30 a.m. to 4.30 p.m. Various new items will be on sale, including a new LHC booklet for the general public. In the style of a travel log, it recounts the fabulous voyage of a proton inside the accelerator. The text is complemented by eye-catching photos and illustrations and is available in English or French. The 2009 calendar, based on the same theme, will also be on sale at 10 CHF. Special reductions will be available on certain items. So come and stock up on your Christmas presents at the CERN shop. Bookshop If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in Physics, ...

  1. Danish TV Christmas calendars: Folklore, myth and cultural history

    DEFF Research Database (Denmark)

    Agger, Gunhild

    2013-01-01

    This article aims at characterizing the Danish Christmas calendar as a TV institution and a meeting place for the traditions of the almanac, folklore and the history of culture. Against the background of a brief outline of the history of Danish Christmas calendars, the article explores ways...... in which this traditional genre has succeeded in renewing itself. The so-called Pyrus series, TV 2’s Christmas calendars during the mid-1990s, exhibited folklore, myth and cultural history in a combination of entertainment and information. They were succeeded by calendars such as Jul i Valhal/‘Christmas...

  2. 76 FR 69094 - Christmas Tree Promotion, Research, and Information Order

    Science.gov (United States)

    2011-11-08

    ... received from interested parties in four Canadian provinces and the United Kingdom. General Comments in... the assessment. A referendum will be conducted, among producers and importers, three years after the... the Federal Register on November 8, 2010 (75 FR 68512). That rule provided for a 60-day comment...

  3. Culminating Cultural Studies with an International Christmas Fair.

    Science.gov (United States)

    Sesow, F. Wm.

    1983-01-01

    Describes the "International Christmas Fair" developed as a part of "Project Explore: Cultural Studies" program in Fairmont, Nebraska, with an ESEA Title IV grant. Shows how a rural school teaches about the Christmas customs of Holland, Sweden, Mexico, Germany, Colonial America, and England. (AH)

  4. Gothic Writing Elements in A Christmas Carol

    Institute of Scientific and Technical Information of China (English)

    白晓红

    2013-01-01

    Charles Dickens was the greatest critical realists in English literary. Almost all of his novels display his deep concern for the society and great sympathy for the low-class people. A Christmas Carol was written in 1843 when the society was unrest.The author created the gothic atmosphere himself, and put his characters into that situation and combined the gothic writing methods with the critical realism in order that the gothic elements could express a kind of strong convulsion, which could strength his criti⁃cism for the society. At the same time, the Gothicism also helped to deepen his criticism for the society.

  5. And All the Dark Make Bright Like Day: Christmas Books 1960-1972.

    Science.gov (United States)

    Long, Sidney

    This annotated bibliography is prefaced by a brief introduction emphasizing the effect of social and cultural change in the past decade as reflected in Christmas books for children. Ten sections deal with the nights before Christmas, the Nativity, miracles and legends, carols, children and Christmas in other lands, Christmas in America, Christmas…

  6. The ``Christmas burst'' GRB 101225A revisited

    Science.gov (United States)

    Thöne, C. C.; de Ugarte Postigo, A.; Fryer, C. L.; Kann, D. A.

    2015-03-01

    Long GRBs are related to the death of massive stars and reveal themselves through synchrotron emission from highly relativistic jets. The `Christmas Burst' GRB 101225A was an exceptionally long GRB with a thermal afterglow, very different from the standard GRB. Initially, no spectroscopic redshift could be obtained and SED modeling yielded z=0.33. A plausible model was a He-NS star merger where the He-star had ejected part of its envelope in the common envelope phase during inspiral. The interaction between the jet and the previously ejected shell can explains the thermal emission. We obtained deep spectroscopy of the host galaxy which leads to a correction of the redshift to z=0.847. Despite the higher redshift, our model is still valid and theoretically better justified than the alternative suggestion of a blue supergiant progenitor proposed by Levan et al. (2014) for several ``ultra-long'' GRBs.

  7. 93rd Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1992 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 19 species and 989 individual birds were counted.

  8. 92nd Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1991 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 25 species and 2,655 individual birds were counted.

  9. 91st Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1990 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 14 species and 1,469 individual birds were counted.

  10. 89th Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1988 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 9 species and 398 individual birds were counted.

  11. 94th Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1993 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 9 species and 940 individual birds were counted.

  12. 90th Christmas Bird Count : Tewaukon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These are the results of the 1989 Christmas Bird Count on Tewaukon National Wildlife Refuge. A total of 14 species and 1,126 individual birds were counted.

  13. Green Christmas kasvas suureks / Aarne Mäe

    Index Scriptorium Estoniae

    Mäe, Aarne, 1967-

    2004-01-01

    Suurbritannia rockansambli Paradise Lost' kontsertidest 18. dets. Rakvere spordihallis ja Riias Kipsala hallis, rockfestivali Green Christmas korraldamisest Gunnar Viese ja Oleg Knjazevi ühisfirma Baltic East Machine poolt

  14. Immediate allergic and nonallergic reactions to Christmas and Easter cacti

    DEFF Research Database (Denmark)

    Andersen, F; Bindslev-Jensen, C; Stahl Skov, P;

    1999-01-01

    BACKGROUND: Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery. METHODS: The study was based on a questionnaire...... and mucosal symptoms. CONCLUSIONS: Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti....

  15. 热闹的Christmas Day

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    圣诞来历:12月25日圣诞节(Christmas Day)是庆祝基督教创始人耶稣基督(Jesus Christ)出生的日子。据说,上帝决定让他的独生子耶稣基督投生人间,以便人们了解上帝,于是找到了一对夫妇约瑟夫(Josepb)和玛丽娅(Mary)。在梦中天使告诉他们Mary怀的孩子来自圣灵,为了拯救人类,出生后要取名为Jesus。后来人们就把这个男孩称作Jesus Christ,因为Christ意思就是“教世主”。多年后人们一直庆祝着这一生日,这一天叫做Christmas,正是来源于他的名字。

  16. An Unusual Stellar Death on Christmas Day

    Science.gov (United States)

    Thone, C. C.; de Ugarte Postigo, A.; Fryer, C. L.; Page, K. L.; Gorosabel, J.; Aloy, M. A.; Perley, D. A.; Kouveliotou, C.; Janka, H. T.; Mimica, P.; Racusin, J. L.; Krimm, H.; Cummings, J.; Oates, S. R.; Holland, S. T.; Siegel, M. H.; De Pasquale, M.; Sonbas, E.; Im, M.; Park, W. K.; Kann, D. A.; Guziy, S.; Hernandez Garcia, L.; Llorente, A.; Bundy, K.

    2011-01-01

    Long Gamma-Ray Bursts (GRBs) are the most dramatic examples of massive stellar deaths, usually associated with supernovae. They release ultra-relativistic jets producing non-thermal emission through synchrotron radiation as they interact with the surrounding medium. Here we report observations of the peculiar GRB 101225A (the "Christmas burst"). Its gamma-ray emission was exceptionally long and followed by a bright X-ray transient with a hot thermal component and an unusual optical couuterpart. During the first 10 days, the optical emission evolved as an expanding, cooling blackbody after which an additional component, consistent with a faint supernova, emerged. We determine its distance to 1.6 Gpc by fitting the spectral-energy distribution and light curve of the optical emission with a GRB-supernova template. Deep optical observations may have revealed a faint, unresolved host galaxy. Our proposed progenitor is a helium star-neutron star merger that underwent a common envelope phase expelling its hydrogen envelope. The resulting explosion created a GRB-like jet which gets thermalized by interacting with the dense, previously ejected material and thus creating the observed black-body, until finally the emission from the supernova dominated. An alternative explanation is a minor body falling onto a neutron star io the Galaxy

  17. Visual Jokes about Christmas and Santa Claus on the Internet - Why and Why not?

    Directory of Open Access Journals (Sweden)

    Guntis Pakalns

    2012-04-01

    Full Text Available This article analyses a collection of Christmas-related images and video clips found on the Internet. The author started collecting this material in 2005, since that time the material in the form of a PowerPoint presentation has been shown to diverse audiences discussing the context (mainly from the perspective of a folklore researcher while observing the reaction of the audience.The central part of the article is devoted to a brief overview of the most characteristic groups of the jokes (with links to the images, video and descriptions of the traditions: Santa Claus as the bringer of presents, his trip from the northland and his friend Rudolph the Red-Nosed Reindeer, arrival through the chimney, different other persons wearing Santa’s hat (politicians, terrorists, women, animals, etc., Santa’s sexuality, drunken Santa, Santa murdered/killed, etc. In addition, the regional version – Ded Moroz and Snegurochka (Father Frost and the Snowgirl – is discussed here. Parodies related to the topic – the Christmas tree, snowmen and figures made of snow, elves, angels, Chinese horoscope’s “animals of the year”.Some hypotheses regarding the differences, functions, selection and perception of the worldwide available jokes in different social situations (western and post-Soviet world are put forward, also considering social groups and situations, the time before and after Christmas. Why would people need such jokes? An attempt is made to explain it by different “levels of joking” – starting with “simply jokes” with their specific context in the tradition of the particular subject matter and the carnival-like sense of the reversed world (also used by the traders, making the originally rather eerie Santa Claus look like a friendly joker in the “shopping mythology” and jokes as a kind of psychological self-defence – trying to compensate, by way of irony and black humour, for the rapidly changing and excessive tediousness

  18. Christmas cards workshop in a Restricted Access Ward

    Directory of Open Access Journals (Sweden)

    Teresa García

    2003-12-01

    Full Text Available The Christmas cards workshop is an intervention study made in the Restricted Access Ward (RAW of Hospital Gregorio Marañón (Madrid, in December 2001, from the 5th to the 22nd. The object of this study was to assess the effectiveness of this workshop to improve the quality of the RAW patients´ hospital day, through their participation. They made 47 cards, the mean per patient was 1,52. Participation: 91,2% of the patients that fulfilled the inclusion criteria. Drawings and texts alluded to the convict´s perspective of Christmas time, from their own experience. The Christmas cards were exhibited in the hospital and they also were sent to different penitentiary institutions in Madrid, to make the RAW known. The course “Education for health for interdisciplinary projects in penitentiary institutions” was the frame of this workshop.

  19. 29 CFR 778.212 - Gifts, Christmas and special occasion bonuses.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Gifts, Christmas and special occasion bonuses. 778.212... COMPENSATION Payments That May Be Excluded From the âRegular Rateâ Bonuses § 778.212 Gifts, Christmas and... Christmas time or on other special occasions, as a reward for service, the amounts of which are not...

  20. CERN Shop - Christmas Sale on 12 and 13 December

    CERN Multimedia

    2007-01-01

    Looking for Christmas present ideas? As every year, we will be running a CERN Shop stand in the Main Building, ground floor, on Wednesday 12 and Thursday 13 December from 10.30 to 16.30. Some new items will be on sale, such as cool fridge magnets and fleeces. The 2008 CERN calendar will be also available at the price of 10 CHF. Some items will have special reductions. Come and visit the CERN Shop stand and find your Christmas presents. DSU-CO group

  1. CERN Shop - Christmas Sale on 15 and 16 December 2005

    CERN Multimedia

    DSU-CO Group

    2005-01-01

    Looking for Christmas present ideas? As every year, we will be running a CERN Shop Stand in the Main Building, ground floor, on Thursday 15 and on Friday 16 December from 10.30 to 16.00. Some new articles will be on sale and special reductions are given for articles such as 50th Anniversary T-shirts (15,-), all silk ties (30,-) and 50th Anniversary watches (35,-). Come and visit the CERN Shop Stand and find your Christmas presents. DSU-CO group

  2. Protocol for fir tree sampling for provenance studies

    Science.gov (United States)

    Meisel, Thomas; Bandoniene, Donata; Zettl, Daniela

    2014-05-01

    Isotopic (stable and radiogenic) as well as trace element fingerprinting methods used for tracing the geographical origin, rely on databases, that need to contain data sets representative of the measurands of the individual samples for a specific geographic entity. Through this work, we want to assess different sampling strategies for obtaining representative sample of fir trees (Abies sp.). Motivation for this work is the protection of the local Austrian Christmas tree market from wrongly tagged trees of non-Austrian origin. In particular, we studied three typical Christmas trees the most common species sold as Christmas tree, namely Abies nordmanniana (Nordmann Fir), from the same locality in lower Austria. For the initial tests we applied the elemental fingerprinting method, to study the suitability of the different parts of the tree applying ICP-MS analysis after complete acid digestion in a high pressure asher system (HPA-S).Needle samples from each year of life of the tree and stem wood from three different heights were analyzed for their trace element content to prove the repeatability and to find the best sampling protocol. For the analysis of the needles, the natural wax coating had to be removed in order to get reproducible results. For the analysis of stem wood only the bark was removed. As expected the data of all three trees allowed the differentiation of the individual needle ages, but interestingly enough also between the three sampling heights of the needs. Both needles and wood proved to be suitable for successful fingerprinting, but importantly, provided that sample of the same type and ages are compared. The same samples for the three trees will also be used for isotopic analysis studies to better understand the influence of age and sampling height on the representativeness of fir tree samples. Based on elemental fingerprinting alone, a successful discrimination between local (Austrian) and foreign (Danish, Irish) Christmas trees was possible.

  3. The Hollow Holiday: Christmas, A Time of Death in Appalachia.

    Science.gov (United States)

    Marriott, Cindy; Harshbarger, Dwight

    An inquiry was conducted into the question of the influence of Christmas and Easter on the occurrence of death. The authors hypothesized that dying might be postponed until after these two important events resulting in a significantly increased frequency of death after these holidays. Obituaries were read for 4 weeks before and 4 weeks after each…

  4. Christmas Orders:To Take or Not to Take?

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Christmas season is quickly approaching,and China’s exporters are like elves busy making holiday gifts to be transported and sold worldwide.But while large velumes of orders usually bring happiness in profits,this year,it’s bringing on headaches instead.

  5. Christmas and Easter Art Programs in Elementary School.

    Science.gov (United States)

    Duncum, Paul

    2000-01-01

    Describes art programs that were given at several elementary Australian schools focusing on Christmas and Easter. Explains that the programs are based on the accounts of the birth and death of Jesus given in the Bible. States that the programs integrate studio art, art criticism, and art history. (CMK)

  6. Bah humbug: Unexpected Christmas cards and the reciprocity norm.

    Science.gov (United States)

    Meier, Brian P

    2016-01-01

    The reciprocity norm refers to the expectation that people will help those who helped them. A well-known study revealed that the norm is strong with Christmas cards, with 20% of people reciprocating a Christmas card received from a stranger. I attempted to conceptually replicate and extend this effect. In Study 1, 755 participants received a Christmas card supposedly from a more- versus less-similar stranger. The reciprocation rate was unexpectedly low (2%), which did not allow for a test of a similarity effect. Two potential reasons for this low rate were examined in Study 2 in which 494 participants reported their likelihood of reciprocating a Christmas card from a stranger as well as their felt suspicions/threat about the card and their frequency of e-mail use. Reciprocation likelihood was negatively correlated with perceived threat/suspicion and e-mail use. It appears that reciprocating a gift from a stranger in offline settings may be less likely than expected.

  7. Cultural Influences on Number Preferences: Christmas and Grading Systems

    Science.gov (United States)

    Stieger, Stefan; Krizan, Zlatan

    2013-01-01

    People consistently prefer numbers associated with themselves (e.g., birth dates) over other numbers. We argue that such number preferences are also shaped by cultural influences, such as customs regarding the day on which Christmas is celebrated and customs regarding ranking of numerals used in national school's grading system. Across 6 different…

  8. The impact of television advertising on children's Christmas wishes

    NARCIS (Netherlands)

    Buijzen, M.A.; Valkenburg, P.M.

    2000-01-01

    In December 1997,250 children were asked to list their Christmas wishes. These requests were then compared to the commercials that were broadcast at the time of data collection. Sixty-seven percent of the seven- and eight-year-olds, 49% of the 9- and 10-year-olds, and 40% of the 11-and 72-year-olds

  9. Women's club - Christmas Sale - Solidarité Femmes

    CERN Multimedia

    CERN Women's club

    2010-01-01

    Thursday, 25 November from 9am to 3pm Main Building 60, Ground floor All proceeds from the sale will be given to the charity Solidarité Femmes Numerous items for sale: Christmas wreaths, Cakes and Biscuits, Coffee, Preserves, Paintings, Books, Embroidery, Patchwork, Painting on porcelain... Tombola! Win a patchwork quilt, handmade by CWC members. All are welcome!

  10. Three more Mangrove trees growing locally in nature in freshwater

    NARCIS (Netherlands)

    Steenis, van C.G.G.J.

    1984-01-01

    In Christmas Island (Indian Ocean) the mangrove trees Bruguiera gymnorrhiza (L.) Sav., B. sexangula (Lour.) Poir. (Rhizophoraceae) and Heritiera littoralis Ait. (Sterculiaceae) are found inland near freshwater springs at some 20-30 m altitude, far from the beach. It is concluded that the inland stan

  11. Phase and coherence analysis of VHF scintillation over Christmas Island

    Science.gov (United States)

    Shume, E. B.; Mannucci, A. J.; Caton, R.

    2014-03-01

    This short paper presents phase and coherence data from the cross-wavelet transform applied on longitudinally separated very high frequency (VHF) equatorial ionospheric scintillation observations over Christmas Island. The phase and coherence analyses were employed on a pair of scintillation observations, namely, the east-looking and west-looking VHF scintillation monitors at Christmas Island. Our analysis includes 3 years of peak season scintillation data from 2008, 2009 (low solar activity), and 2011 (moderate solar activity). In statistically significant and high spectral coherence regions of the cross-wavelet transform, scintillation observations from the east-looking monitor lead those from the west-looking monitor by about 20 to 60 (40 ± 20) min (most frequent lead times). Using several years (seasons and solar cycle) of lead (or lag) and coherence information of the cross-wavelet transform, we envisage construction of a probability model for forecasting scintillation in the nighttime equatorial ionosphere.

  12. Is a White Christmas becoming rarer in southern parts of Sweden?

    Science.gov (United States)

    Rydén, Jesper

    2015-07-01

    The notion of White Christmas, for instance snow conditions at Christmas Day, is occasionally discussed among people in certain countries in the northern hemisphere. In this paper, the state of snow occurrence at Christmas Day at locations in Sweden are primarily considered binary events and methodology for statistical analysis of time series with binary responses is employed to investigate trend over time. None of the six locations studied showed a significant change over time.

  13. The Christmas Season as a Risk Factor for Chronic Obstructive Pulmonary Disease Exacerbations

    Directory of Open Access Journals (Sweden)

    Neil W Johnston

    2010-01-01

    Full Text Available BACKGROUND: Epidemics of hospitalization for chronic obstructive pulmonary disease (COPD occur annually during the Christmas holidays, and COPD exacerbations commonly coincide with respiratory viral infections.

  14. The Stuff of Christmas Homemaking: Transforming the House and Church on Christmas Eve in the Bay of Kotor, Montenegro

    Directory of Open Access Journals (Sweden)

    Vesna Vučinić-Nešković

    2016-03-01

    Full Text Available The domestic burning of Yule logs on Christmas Eve is an archaic tradition characteristic of the Christian population in the central Balkans. In the fifty years following World War Two, the socialist state suppressed these and other popular religious practices. However, ethnographic research in Serbia and Montenegro in the late 1980s showed that many village households, nevertheless, preserved their traditional Christmas rituals at home, in contrast to the larger towns, in which they were practically eradicated. Even in the micro-regions, such as the Bay of Kotor, there were observable differences between more secluded rural communities, in which the open hearth is still the ritual center of the house (on which the Yule logs are burned as many as seven times during the Christmas season, and the towns in which only a few households continued with the rite (burning small logs in the wood-stove. In the early 1990s, however, a revival of domestic religious celebrations as well as their extension into the public realm has occurred. This study shows how on Christmas Eve, houses and churchyards (as well as townsquares are being transformed into sacred places. By analyzing the temporal and spatial aspects of this ritual event, the roles that the key actors play, the actions they undertake and artifacts they use, I attempt to demonstrate how the space of everyday life is transformed into a sacred home. In the end, the meanings and functions of homemaking are discussed in a way that confronts the classic distinction between private and public ritual environs.

  15. Combining Propagation Information and Search Tree Visualization using ILOG OPL Studio

    OpenAIRE

    Bracchi, Christiane; Gefflot, Christophe; Paulin, Frederic

    2001-01-01

    In this paper we give an overview of the current state of the graphical features provided by ILOG OPL Studio for debugging and performance tuning of OPL programs or external ILOG Solver based applications. This paper focuses on combining propagation and search information using the Search Tree view and the Propagation Spy. A new synthetic view is presented: the Christmas Tree, which combines the Search Tree view with statistics on the efficiency of the domain reduction and on the number of th...

  16. "A CHRISTMAS CAROL" BY CHARLES DICKENS AS A MEDIATOR WORK AND TYPE OF CULTURE

    Directory of Open Access Journals (Sweden)

    Mikhnovets N. G.

    2008-11-01

    Full Text Available The article examines Charles Dickens’s novel "A Christmas Carol" that correlates with the biblical history and sacred images enshrined in the Western European Figurative Art. This C. Dickens’s novel, based on the Old Testament and the New Testament foundation, promoted the restoration of the Christmas story.

  17. La Celebracion de Navaidad. Para la Secundaria. (The Celebration of Christmas, Secondary Level.)

    Science.gov (United States)

    Herrera, Gloria; Lizcano, Jeanette

    The celebration of Navidad (Christmas) by various cultures is the topic of this secondary level unit. Unit objectives are that the student will be able to differentiate between his culture's Christmas customs and those of the dominant culture, and be able to relate their origin. The customs of Mexico, Panama, and south Texas are discussed. Also…

  18. Teaching child growth and development: the Christmas shoebox.

    Science.gov (United States)

    Epp, Sheila M; McAulay, Judy E

    2008-01-01

    Teaching growth and development to nursing students can be dry, uninteresting, and labor-intensive. Engaging students in learning this material was the challenge of a short, 4-week pediatric experience. Students use growth and development knowledge to select toys and activities that fit in a shoebox and explain to their classmates the rationale for their selection. The Christmas shoebox activity increases their ability to transfer knowledge to both the examination questions and the clinical setting and provides a charitable service to the community.

  19. GRB 101225A: an unusual stellar death on Christmas Day

    Science.gov (United States)

    Thöne, C. C.; de Ugarte Postigo, A.; Fryer, C. L.; Page, K. L.; Gorosabel, J.; Aloy, M.; Perley, D.

    2013-05-01

    Gamma-ray bursts are usually followed by afterglows produced by synchrotron radiation which makes them detectable out to the far Universe. Here we present the unusual GRB 101225A, also named the ``Christmas burst'', an extremely long γ-ray burst followed by a bright X-ray afterglow and a peculiar optical counterpart. The X-ray spectrum shows an additional thermal component while the UV-optical-IR SED evolves as a cooling, expanding black-body until 10 days, after which a faint supernova emerges. With GTC/OSIRIS, we detect an extremely faint host galaxy 6 months after the burst.

  20. Tree sets

    OpenAIRE

    Diestel, Reinhard

    2015-01-01

    We study an abstract notion of tree structure which generalizes tree-decompositions of graphs and matroids. Unlike tree-decompositions, which are too closely linked to graph-theoretical trees, these `tree sets' can provide a suitable formalization of tree structure also for infinite graphs, matroids, or set partitions, as well as for other discrete structures, such as order trees. In this first of two papers we introduce tree sets, establish their relation to graph and order trees, and show h...

  1. The Cultural Contrast between the Custom of Spring Festival and Christmas

    Institute of Scientific and Technical Information of China (English)

    殷川川

    2010-01-01

    Spring Festival and Christmas are important festivals in China and western countries.They have different cultural connotations.The traditional Chinese culture represented by Spring Festival and the western culture characterized by Christmas differ in many respects,including the difference between ancestor reunion and the family reunion non-religiousness and religiousness,secularism and non-secularism,ancestor worship and God worship.A clear understanding of the difference between Spring Festival and Christmas contributes to the culture exchange among Chinese and western people.

  2. News from the library: CERN Bookshop christmas sales

    CERN Multimedia

    CERN Library

    2010-01-01

    If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in Physics, Mathematics and Computing.   It will have a stall in the Ground Floor of the Main Building (Bldg 500) from 7 to 8 December 2010. You are welcome to come, browse and buy books at very interesting prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052 and is open on weekdays from 8.30 a.m. to 7.00 p.m. It can be contacted by e-mail at bookshop@cern.ch. CERN Users can buy books and CDs at discount prices.

  3. News from the Library: CERN Bookshop Christmas sales

    CERN Multimedia

    CERN Library

    2012-01-01

    If you are looking for an idea for your Christmas gifts, CERN's Central Library Bookshop offers a wide choice of titles in physics, mathematics, computing and popular science.   The Bookshop will have a stand on the Ground Floor of the Main Building (Building 500) from 4 to 5 December 2012. You are welcome to come by, and browse and buy books at very competitive prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052, and is open on weekdays from 8.30 a.m. to 7.00 p.m. You can contact the Bookshop by e-mail. Accepted forms of payment in the Bookshop are: cash, credit card and budget code. You can also purchase books using your budget code via the CERN Stores: "Catalogue - CERN Stores" > "BOOKS - PUBLICATIONS" (category 90).

  4. News from the Library: CERN Bookshop Christmas sales

    CERN Multimedia

    CERN Library

    2011-01-01

    If you are looking for an idea for your Christmas gifts, the Bookshop of the Central Library offers you a wide choice of titles in physics, mathematics, computing and popular science.   The Bookshop will have a stand on the Ground Floor of the Main Building (Bldg 500) from 12 to 13 December 2011. You are welcome to come, browse and buy books at very interesting prices! The title list of the Bookshop is available here. This Bookshop is located in the Central Library, Building 52 1-052, and is open on weekdays from 8.30 a.m. to 7.00 p.m. You can contact the Bookshop by e-mail at bookshop@cern.ch. Accepted forms of payment in the Bookshop are: cash, credit card and budget code. You can also purchase books using your budget code via the CERN Stores: http://edh.cern.ch > "Catalogue - CERN Stores" > "BOOKS - PUBLICATIONS" (category 90).

  5. CERN SHOP - CHRISTMAS SALE - 11-12.12.2002

    CERN Multimedia

    Visits & Exhibition Service

    2002-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Wednesday 11 to Thursday 12 December from 10.30 to 16.00. CERN Sweat-shirts(M, L, XL) 30.- CERN T-shirt,(M, L, XL) 20.- New CERN silk tie (2 colours) 35.- Blue silk tie 15.- Fancy silk tie (blue, bordeau) 20.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- Swiss Duo Pack with CERN logo 30.- CERN watch 20.- CERN baseball cap 15.- CERN briefcase 15.- Book 'Antimatter' (English) 35.- Book 'Particle Odyssey' (English) 60.- Book 'How the web was born' (English, Italian) 30.- The Search for Infinity (French, Italian, English, German)  40.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.00 hrs. Visits & Exhibition Service/ETT-VE

  6. CERN Shop - Christmas Sale 15-17.12.2003

    CERN Multimedia

    2003-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand: in Meyrin, Main Building, ground floor, from Monday 15 to Wednesday 17 December from 10:30 to 16:00 hrs. CERN Sweat-shirts (M, L, XL) 30.- CERN T-shirt, (M, L, XL) 20.- CERN silk tie (2 colours) 35.- Fancy silk tie (blue, bordeau) 20.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- Swiss Duo Pack with CERN logo 30.- CERN/Atlas watch 40.- CERN baseball cap 15.- CERN briefcase 15,- Mouse mat 10,- CERN Calendar 5,- Books: - "Antimatter" (English) 35.- - "How the web was born" (English, Italian) 30,- - "The Search for Infinity" (French, Italian, English, German) 40.- - "World of Particles/le monde de particules" 6,- - "Facts and Mysteries" (English) 28,- - "Nucleus" (English) 50,- If you miss this special occasion, the articles are also available at the Reception Shop in Buildin...

  7. Event Ethnography: A Modern Approach to Anthropological Research and Writing about Christmas

    Directory of Open Access Journals (Sweden)

    Lidija Radulović

    2016-03-01

    Full Text Available "Event Ethnography": A Modern Approach to Anthropological Research and Writing about Christmas. Review of the book by Vesna Vučinić-Nešković,  Christmas in Boka Kotorska: anthropological essays of public firings of the Yule log in the time of post socialism. The Faculty of Philosophy, University of Belgrade and "Čigoja publishing". Belgrade 2008. 357 pages.

  8. Significantly higher Carabid beetle (Coleoptera: Carabidae) catch in conventionally than in organically managed Christmas tree plantations

    DEFF Research Database (Denmark)

    Bagge, Søren; Lund, Malthe; Rønn, Regin;

    2012-01-01

    trapped carabid beetles (Coleoptera, Carabidae) varied between conventionally and organically managed Caucasian Fir (Abies nordmanniana (Stev.)) plantations, in northern Zealand, Denmark. We recorded significantly higher numbers of carabid beetle specimens and species at conventionally than at organically...

  9. 'THEY LIGHT THE CHRISTMAS TREE IN OUR TOWN': Reflections on Identity, Gender, and Adolescent Sports.

    Science.gov (United States)

    Miller, Kathleen E

    2009-12-01

    Sport occupies a prominent space in the public lives and private identities of US adolescents. Using the retrospective reflections of college students, this analysis explores two questions about sport-related identities during high school: Are 'athletes' and 'jocks' distinctly separate identities? Are these identities explicitly gendered? In four gender-segregated focus groups conducted in early 2005, 32 student-athletes from two upstate New York colleges discussed their high school experiences of sport, status, gender, and identity. Three primary themes developed with regard to differences between the 'jock' and 'athlete' archetypes: academic focus, teamwork, and cockiness/aggression. Examining the intersection of gender, high-status/high-profile sport, and identity in both popular cultural imagery and the personal experiences of the focus group discussants provided support for the thesis of a 'toxic jock' phenomenon. PMID:20835368

  10. 76 FR 71241 - Christmas Tree Promotion, Research, and Information Order; Stay of Regulations

    Science.gov (United States)

    2011-11-17

    ... regulations. SUMMARY: On November 8, 2011, a final rule was published in the Federal Register (76 FR 69094... Agriculture (Department) published in the Federal Register on November 8, 2011, (76 FR 69094) a final rule... regulations establishing the Order published November 8, 2011 (76 FR 69094) are stayed indefinitely....

  11. 76 FR 69110 - Christmas Tree Promotion, Research, and Information Order; Referendum Procedures

    Science.gov (United States)

    2011-11-08

    ... (75 FR 68512) and a second rule pertained to proposed referendum procedures (75 FR 68529). Both rules... (76 FR 9695). Five hundred and sixty five comments were received regarding the proposed Order. Those... published in the Federal Register on November 8, 2010 (75 FR 68529). Copies of the rule were made...

  12. Significantly Higher Carabid Beetle (Coleoptera: Carabidae) Catch in Conventionally than in Organically Managed Christmas Tree Plantations

    DEFF Research Database (Denmark)

    Bagge, Soren; Lund, Malthe; Ronn, Regin;

    2012-01-01

    Carabid beetles play an important role as consumers of pest organisms in forestry and agriculture. Application of pesticides may negatively affect abundance and activity of carabid beetles, thus reducing their potential beneficial effect. We investigated how abundance and diversity of pitfall tra...

  13. Micropropagation and Biotechnology in Forestry: Preliminary Results From the Danish Christmas Tree Improvement Programme

    DEFF Research Database (Denmark)

    Kristensen, Michel Mehlby Holst; Find, Jens; Krogstrup, Peter

    2004-01-01

    The principal methods of micropropagation (in vitro propagation or tissue culture) are axillary budding, induction of adventitious buds, and somatic embryogenesis (where individual cultured cells or small groups of cells undergo development resembling that of the zygotic embryo. These methods...... are very expensive compared to conventional vegetative propagation due to the costly equipment and the technical staff that is needed to perform the techniques. An additional disadvantage of micropropagation is that it may lead to unwanted genetic alterations, e.g., somaclonal variation (George, 1993...

  14. CERN Shop: Christmas Sale, 10 & 16.12.2004

    CERN Multimedia

    2004-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, on Friday 10 and/or on Thursday 16 December from 10:30 to 16:00. CERN 50th Anniversary sweat-shirt (grey in M, L, XL) 30.- CERN 50th Anniversary T-shirt, (S, M, L, XL) 20.- CERN 50th Anniversary silk tie (2 colours) 30.- Einstein silk tie (blue, grey) 45.- Silk scarf 40.- Swiss army knife with CERN logo 25.- Swiss Duo-Pack with CERN logo 30.- CERN 50th Anniversary watch (2 models) 40.- CERN pens (2 models) 5.- Small Open Day souvenirs (a few different items) 2.- CERN 50th Anniversary Book (English & French) 70.- "Prestigious Discoveries" at CERN (English/anglais) 32.- "Particle Odyssey" soft cover (English/anglais) 35.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08:30 and 17:00 hrs. Education and Communica...

  15. THE TRANSFORMATION OF THE GENRE OF THE CHRISTMAS STORY IN MODERN LITERATURE (D. BYKOV, L. PETRUSHEVSKAYA

    Directory of Open Access Journals (Sweden)

    Yulia Yur'evna Danilenko

    2014-11-01

    Full Text Available Article is devoted to the study of the transformation of the genre of the Christmas story in modern literature. Th e article analyzes the infl uence of the classic Christmas story by Hans Christian Andersen Th e Little Match Girl on the structure of modern texts of mass and elite literature. (D. Bykov Th e Little Match Girl gives a light, L. Petrushevskaya Black Coat. Th e subject of the study is a strategy of rethinking, recoding the source of the original content in the fabric of a new product. Th e structural and semiotic analysis of the texts revealed some tricks to updates-the-genre: fi lling-up with the new semantics, complicating a genre model of a Christmas story. Analysis showed that referring to the genre of a Christmas story, modern authors have diff erent purposes, using diff erent artistic strategies and methods. Some of them tend to reproduce the canon, appealing to the reader's memory (D. Bykov. Others develop the genre of a Christmas story, enriching it with new structural elements, interlacing it with other genres (L. Petrushevskaya.

  16. Planting Trees

    OpenAIRE

    Relf, Diane

    2009-01-01

    The key aspects in planning a tree planting are determining the function of the tree, the site conditions, that the tree is suited to site conditions and space, and if you are better served by a container-grown. After the tree is planted according to the prescribed steps, you must irrigate as needed and mulch the root zone area.

  17. 78 FR 71493 - Special Local Regulation; Lake Havasu City Christmas Boat Parade of Lights; Colorado River; Lake...

    Science.gov (United States)

    2013-11-29

    ... Acronyms BNM Broadcast Notices to Mariners COTP Captain of the Port DHS Department of Homeland Security FR... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA00 Special Local Regulation; Lake Havasu City Christmas... in support of the Lake Havasu City Christmas Boat Parade of Lights on the Colorado River....

  18. The Use of Magic/Mythic Stories and Their Relevance to Children's Development: The Case of the Father Christmas Story.

    Science.gov (United States)

    Papatheodorou, Theodora; Gill, Janet

    The story of Father Christmas is widespread across Europe and beyond, and for almost six weeks each year dominates children's and adults' lives. This longitudinal study examined parental practices and attitudes towards the Father Christmas story. Participating during the first phase of the study, conducted during November and December 1998, were…

  19. Using Christmas Bird Count data in analysis of population change

    Science.gov (United States)

    Sauer, J.R.; Link, W.A.

    2002-01-01

    The scientific credibility of Christmas Bird Count (CBC) results depend on the development and implementation of appropriate methods of statistical analysis. The key to any successful analysis of CBC data is to begin with a careful review of how the limitations of the data are likely to influence the results of the analysis, then to choose methods of analysis that accommodate as much as possible the limitations of the survey. For our analyses of CBC data, we develop a flexible model for effort adjustment and use information from the data to guide the selection of the best model. We include geographic structuring to accommodate the regional variation in number of samples, use a model that allows for overdispersed poisson data appropriate for counts, and employ empirical Bayes procedures to accommodate differences in quality of information in regional summaries. This generalized linear model approach is very flexible, and can be applied to a variety of studies focused on factors influencing wintering bird populations. In particular, the model can be easily modified to contain covariates, allowing for assessment of associations between CBC counts and winter weather, disturbance, and a variety of other environmental factors. These new survey analysis methods have added value in that they provide insights into changes in survey design that can enhance the value of the information. The CBC has been extremely successful as a tool for increasing public interest in birding and bird conservation. Use of the information for bird conservation creates new demands on quality of information, and it is important to maintain a dialogue between users of the information, information needs for the analyses, and survey coordinators and participants. Our work as survey analysts emphasizes the value and limitations of existing data, and provides some indications of what features of the survey could be modified to make the survey a more reliable source of bird population data. Surveys

  20. CHRISTMAS AND EASTER THEMES IN THE LITERARY HERITAGE OF YURIY MIROLYUBOV

    Directory of Open Access Journals (Sweden)

    Sergey F. Dmitrenko

    2015-11-01

    Full Text Available A  Russian emigrant writer Yuri Mirolyubov (1892—1970 wrote a  lot about Slavic antiquities. His name is associated with the origin of a  legendary “The book of Veles”  (Velesova kniga. This article studies his literary works in a historical and literary context, thematically associated with Christmas and Easter. The son of a priest, Mirolyubov was able to create original Christmas and Easter tales. As a priest’s son Mirolyubov managed to create indigenous Christmas and Easter stories. He brought back an already existing genre tradition of Christmas and Easter literature to its folklore origins, freed it from absolutely literary accretions and narrative stereotypes. Yuri Mirolyubov strived to put the Christmas and Easter stories beyond moral (much less entertaining literature, put them in the mainstream of a  folk, “Russian epic” (Ivan Shmelyov. That was a defi nition given by an author Ivan Shmelyov to his writing “The Lord’s summer”  (Leto Gospodne, who also updated the Canon of Russian calendar (Christmas and Easter literature in his own way. In fictional prose Yuri Mirolyubov acted as a scientist-ethnographer, a  sensitive receptionist of  everyday phenomena and psychological states. But in the works defi ned as scientific, he became a true artist, who felt free to deal with the most complicated and poorly studied material, however, existing in the depths of people’s consciousness.

  1. Christmas Holiday Season in the U.S.A.

    Institute of Scientific and Technical Information of China (English)

    Bill; Hofmann

    1999-01-01

    美国教授 Bill Hofmann并非第一次为我刊写文章。在去年第 11期,我们就曾读过他的“答一位65岁的中国老人问”。我们曾约请几位美国教授撰文。谈西方的一个重大节日:Christmas,在几篇来稿中,Bill教授的文章让我们编辑先睹为快,齐声叫好!他的文章,不是浮光掠影地描述些我们已经略知一二的圣诞节热闹场面,而是抒发了自己对这个节日的观察和分析,我们不想用“振聋发聩”这样的字眼去形容他的文章,但是,此文确实如一杯浓郁的咖啡,值得细细品味其袅袅的金香。文章不仅有人本的观察,到位的分析,而且,其文字也非常优美。我们非常感谢Bill教授为本刊撰稿。应本刊的要求,Bill教授对自己的个人情况,作了简单的自我介绍。全文如下: I recently retired after 35 years of teaching writing at the university andcollege level.Prior to that,I worked as a technical writer at the BoeingCompany,and recently as a researcher and exhibits writer at the Museum ofFlight,hoth in Seattle,Washington.As a consultant,I worked for 8 years as aneditor and writer for the Warren Reading Foundation.As a freelance writer,Ihave authored books and shorter works in both fiction and non-fiction.I haved

  2. Autoencoder Trees

    OpenAIRE

    İrsoy, Ozan; Alpaydın, Ethem

    2014-01-01

    We discuss an autoencoder model in which the encoding and decoding functions are implemented by decision trees. We use the soft decision tree where internal nodes realize soft multivariate splits given by a gating function and the overall output is the average of all leaves weighted by the gating values on their path. The encoder tree takes the input and generates a lower dimensional representation in the leaves and the decoder tree takes this and reconstructs the original input. Exploiting t...

  3. 78 FR 35593 - Special Local Regulation; Christmas Boat Parade, San Juan Harbor; San Juan, PR

    Science.gov (United States)

    2013-06-13

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... public dockets in the January 17, 2008, issue of the Federal Register (73, FR 3316). 4. Public Meeting We... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; Christmas Boat Parade,...

  4. Reproductive Development of the Christmas Rose (Helleborus niger L.): The Role of Plant Hormones

    OpenAIRE

    Salopek Sondi, Branka

    2011-01-01

    Christmas rose (Helleborus niger L.), a native perennial of southeastern Europe, is characterized by an interesting phenomenon in the world of flowering plants: after fertilization perianth becomes green, photosyntheticaly active, and persists during fruit development. Removal of the reproductive organs (anthers and carpels) affects the elongation and vascular anatomy of flower stalk, prevents complete perianth greening, and promotes perianth senescence. Endogenous plant hormones ...

  5. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  6. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  7. Abundance patterns of macrofauna and infauna in nursery habitats of Christmas Bay, Texas: July 1984 through June 1985.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Between July 1984 and June 1985, monthly samples were collected from marsh, seagrass, and nonvegetated habitats in Christmas Bay and West Bay in the Galveston Bay...

  8. Talking Trees

    Science.gov (United States)

    Tolman, Marvin

    2005-01-01

    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…

  9. Kuu kultuurikulgur : Noaga tehtud plaadikaaned. Chungini jõulupidu : Hare Christmas! 6 miljonit digitaalaaret

    Index Scriptorium Estoniae

    2008-01-01

    Pastaca uue heliplaadikogumiku "Remiksid" esitlusest 19. dets. Tallinnas klubis Juuksur ja 20. dets. Tartus klubis Maailm (kaasa mängivad Galaktlan ja Hannes Praks). 16. dets. avab Tartus Lastekunstikooli galeriis uksed muusiku ja usuteaduslase Chungini kuraatoriprojekt "Hare Christmas/Guten Weichnachten". 20. nov. avati sait www. europeana.eu, mille eesmärgiks anda allalaadimiseks Euroopa kultuuriväärtusi (sümfooniad, poeemid ja maalid digitaliseeritud kujul)

  10. Haunted Seasons: Television Ghost Stories for Christmas and Horror for Halloween

    OpenAIRE

    Johnston, Derek

    2015-01-01

    Why do the English have ghost stories at Christmas? Why does US television have special Halloween episodes? Is this all down to Dickens, or is it a hangover of an ancient, pagan past? Why does it survive? Haunted Seasons explores these and related questions, examining the history and meaning of seasonal horror. It reaches back through archaeological evidence of ancient beliefs, through Shakespeare, and Victorian ghost stories, and the works of M.R.James, and onwards to radio and television. T...

  11. Holy Trees

    OpenAIRE

    Elosua, Miguel

    2013-01-01

    Puxi's streets are lined with plane trees, especially in the former French Concession (and particularly in the Luwan and Xuhui districts). There are a few different varieties of plane tree, but the one found in Shanghai, is the hybrid platane hispanica. In China they are called French Plane trees (faguo wutong - 法国梧桐), for they were first planted along the Avenue Joffre (now Huai Hai lu - 淮海路) in 1902 by the French. Their life span is long, over a thousand years, and they may grow as high as ...

  12. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  13. Game tree algorithms and solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1998-01-01

    textabstractIn this paper, a theory of game tree algorithms is presented, entirely based upon the concept of solution tree. Two types of solution trees are distinguished: max and min trees. Every game tree algorithm tries to prune nodes as many as possible from the game tree. A cut-off criterion in

  14. Dry tree semisubmersible platform: from 'technology accepted' to 'project ready'

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Roger; Wang, Tao; Nygaard, Magne; Bendiksen, Rolf [Aker Solutions, Oslo (Norway)

    2012-07-01

    Development of new technologies for application of dry tree solutions on semi-submersible hull production platforms opens up new flexible and cost efficient solutions for oil and gas fields in deep and ultra deep water. Aker Solutions has brought the technology through the last steps to a project ready stage. Top tension risers allow for shifting the Christmas tree from seabed to topside, and enables drilling and production from the same unit. By shifting the wellhead and Christmas tree from seabed to platform deck, well maintenance is simplified, and makes the Dry Tree Semi relevant to consider for the Brazilian pre-salt reservoirs. Easy access to the wells for maintenance gives a potential for a higher recovery rate for the field. Future development of ultra deep water oil and gas fields demands solutions overcoming the limitations set by the TLP and the Spar buoy. Combining knowledge from already proven solutions, and a limited addition of new technology, these limitations are overcome with Aker Solutions' Dry Tree Semi. It is designed and proven for Gulf of Mexico environmental conditions. It is verified for conditions with a significant wave height of 14 meters, and able to withstand 100-year extreme weather and 1000-years survival conditions. A conventional semi-submersible platform, but with a deeper draft to further reduce the already low motions, makes the basis for the concept. Top tensioned risers (TTR) with vertical motion compensation stroke of up to 10 meters, makes it possible to shift the Christmas tree from seabed to platform deck. The deep draft design of the hull reduces the wave force excitation on the pontoons, reducing both the roll and pitch dynamics. The Dry Tree Semi represents several major benefits, including low sensitivity to water depth, reduced hull and topside weight, and flexibility in transportation, mooring, and decommissioning. (author)

  15. Interpreting Tree Ensembles with inTrees

    OpenAIRE

    Deng, Houtao

    2014-01-01

    Tree ensembles such as random forests and boosted trees are accurate but difficult to understand, debug and deploy. In this work, we provide the inTrees (interpretable trees) framework that extracts, measures, prunes and selects rules from a tree ensemble, and calculates frequent variable interactions. An rule-based learner, referred to as the simplified tree ensemble learner (STEL), can also be formed and used for future prediction. The inTrees framework can applied to both classification an...

  16. Aspen Trees.

    Science.gov (United States)

    Canfield, Elaine

    2002-01-01

    Describes a fifth-grade art activity that offers a new approach to creating pictures of Aspen trees. Explains that the students learned about art concepts, such as line and balance, in this lesson. Discusses the process in detail for creating the pictures. (CMK)

  17. Sentiment and Vision in Charles Dickens's A Christmas Carol and The Cricket on the Hearth

    Directory of Open Access Journals (Sweden)

    Heather Tilley

    2007-04-01

    Full Text Available This essay explores the ways in which sentimentality is manifested through the visible, and through associative functions of the eye, in two of Dickens's Christmas books of the 1840s. I situate the relationship between vision and sentiment within discourses from eighteenth-century moral philosophy, as Adam Smith's figure of the “Impartial Spectator” (of central importance to the development of ideas around sympathy is constructed mainly through the visual. I focus on two of the Christmas Books as they offer an interesting local study to test these ideas, coming at a critical juncture within the development of Dickens's own writing style, and also at an important historical moment within an investigation into Victorian sentimentality. Within Dickens's writing, sentimentality is typically associated with the exaggerated emotional portrayal of pathetic scenes (particularly the deaths of children, designed to elicit emotional responses from the reader. However, behind the hyperbole rests a concern with the self's need to take social, ethical and moral care of others, and the role of literature and art in tutoring the reader's emotional response, with the eye playing a crucial role in this act. I further explore the way in which Dickens's interest in blindness both reinforces, and points to certain disturbances, in his sentimental vision.

  18. Ethno linguistic material regarding Christmas rituals among the Serbs in Bela Krajina

    Directory of Open Access Journals (Sweden)

    Petrović Tanja

    2002-01-01

    Full Text Available The paper aims at presenting the current ethno linguistic situation in four Orthodox Serbian villages in the Bela Krajina region of Slovenia. Ethno linguistic material collected in these villages enables the synchronic state of traditional culture to be established. Special attention is payed to the way the interviewees describe Christmas rituals and interpret and evaluate then-present state; apart from description of Christmas interviewees' statements (here named ethno linguistic texts also carry precious information about attitudes of carriers of a certain culture towards its values, and indicate in- and out-group relations, establishing oppositions such as then vs. now, me vs. them, us vs. them. These subjective comments provided by the interviewees help obtain a complete, multilevel picture of a traditional culture, with all interactions that characterize it, both within the ethno linguistic community and in relation to other communities. It is especially important that these interactions be taken into account for isolated ethnic and linguistic groups such as the Orthodox Serbs in Bela Krajina.

  19. Unimodular trees versus Einstein trees

    Science.gov (United States)

    Álvarez, Enrique; González-Martín, Sergio; Martín, Carmelo P.

    2016-10-01

    The maximally helicity violating tree-level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in the two theories.

  20. Another Hanukkah Miracle: The Gaps Between Consecutive Christmas-in-Hanukkah Years is ALWAYS a Fibonacci Number!

    CERN Document Server

    Ekhad, Shalosh B

    2012-01-01

    The Hebrew Calendar is based on very deep and complicated mathematics, involving diophantine approximation, but it is very surprising that the gaps between consecutive Christmas-in-Hanukkah years is always a member of the set {2,3,5,8}.

  1. Christmas in the "Valley of Praise": Intersections of the Rural Idyll, Heritage and Community in Lobethal, South Australia

    Science.gov (United States)

    Winchester, Hilary P. M.; Rofe, Matthew W.

    2005-01-01

    The village of Lobethal in the Adelaide Hills is synonymous with Christmas. Its annual Festival of Lights originated in the 1940s and now attracts over 250,000 visitors each year. In 1994, the Lobethal Lights Festival Committee took over the coordination of activities and gained serious corporate sponsorship. The formalisation of the Festival…

  2. No Lexical-Prelexical Feedback during Speech Perception or: Is It Time to Stop Playing Those Christmas Tapes?

    Science.gov (United States)

    McQueen, James M.; Jesse, Alexandra; Norris, Dennis

    2009-01-01

    The strongest support for feedback in speech perception comes from evidence of apparent lexical influence on prelexical fricative-stop compensation for coarticulation. Lexical knowledge (e.g., that the ambiguous final fricative of "Christma?" should be [s]) apparently influences perception of following stops. We argue that all such previous…

  3. The Christmas Project That Grew: How Our Students Learned the Curriculum, Helped Other Children, and Became Entrepreneurs.

    Science.gov (United States)

    Figgner, Deb; Sherburne, Cheryl

    1999-01-01

    Two Nebraska teachers of grades 1 and 5 describe how their classes' joint Christmas project developed into an entrepreneurial experience. To raise money for toys for needy children, students applied for a bank loan, assembled bead kits for sale, and established costs and prices. The teachers took advantage of each new idea, turning "road blocks"…

  4. Mantle heterogeneities beneath the Northeast Indian Ocean as sampled by intra-plate volcanism at Christmas Island

    Science.gov (United States)

    Taneja, Rajat; Rushmer, Tracy; Blichert-Toft, Janne; Turner, Simon; O'Neill, Craig

    2016-10-01

    The intra-plate region of the Northeast Indian Ocean, located between the Ninetyeast Ridge and the North West Shelf of Australia, contains numerous submerged seamounts and two sub-aerially exposed volcanic island groups. While the Cocos (Keeling) Archipelago is a coral atoll, Christmas Island is the only sub-aerially exposed volcanic island and contains Late Cretaceous, Eocene and Pliocene lavas. The lavas are predominantly basaltic in composition, except for one sampled flow that is trachytic. Although the evolution of the western margin of Australia, and the seismicity in the intra-plate region, has received considerable attention, the origin of the seamount province in the Northeast Indian Ocean is still a matter of debate. In order to constrain the origin of volcanism on Christmas Island and the associated Seamount Province we analysed 14 Christmas Island samples for major and trace element abundances and 12 of these for Nd, Hf and Pb isotope compositions. The trace element patterns of the lavas are similar to many ocean island basalts, while high 208Pb/204Pb and 207Pb/204Pb at a given 206Pb/204Pb suggest affiliation with the DUPAL anomaly. The reconstructed position of Christmas Island during the Eocene (44-37 Ma) places the island in close proximity to the (present-day) upper mantle low-seismic velocity anomalies. Moreover, an enriched mantle (EM-2) type component in addition to the DUPAL anomaly is observed in the Eocene volcanic phase. The younger Pliocene (~ 4 Ma) sequences at Christmas Island are inferred to be the product of partial melting of existing material induced by lithospheric flexure.

  5. Christmas Stars

    DEFF Research Database (Denmark)

    Andersen, Niels John

    2010-01-01

    Matematiklærere er som regel altid på jagt efter emner og aktiviteter, der kan engagere, fascinere og udfordre eleverne på mange niveauer. At udforske og eksperimentere med design af stjerneformede polyedre er en af de mange muligheder....

  6. Finite Sholander Trees, Trees, and their Betweenness

    CERN Document Server

    Chvátal, Vašek; Schäfer, Philipp Matthias

    2011-01-01

    We provide a proof of Sholander's claim (Trees, lattices, order, and betweenness, Proc. Amer. Math. Soc. 3, 369-381 (1952)) concerning the representability of collections of so-called segments by trees, which yields a characterization of the interval function of a tree. Furthermore, we streamline Burigana's characterization (Tree representations of betweenness relations defined by intersection and inclusion, Mathematics and Social Sciences 185, 5-36 (2009)) of tree betweenness and provide a relatively short proof.

  7. Assessing the impact of a Christmas advertisement campaign on Catalan wine preference using Choice Experiments.

    Science.gov (United States)

    Kallas, Zein; Escobar, Cristina; Gil, José Maria

    2012-02-01

    Our paper seeks to assess the impact of information and advertisement on consumers' preference for wines in special occasions (Christmas) in Catalonia (Spain). We apply the Choice Experiments method to study the relative importance of attributes that describe consumers' decision to purchase wine by using the Heteroskedastic Extreme Value (HEV) model. Data were obtained from two questionnaires applied to a pre and post spot samples formed by 299 and 400 individuals, respectively. Results suggest that the proposed spot does not affect the ranking of the preferred attributes, nevertheless this preference is heterogeneous. After advertising preferences scores have revealed significant differences. The relative importance of the "Catalan" wine has increased compared to the "Spanish" wine. The most preferred product is a Catalan wine made from the "Cabernet Sauvignon" variety. Wines that have been previously tasted by the consumer seem to be preferred over recommended or prestigious wines. However, advertising increases the relative importance of prestigious wines. PMID:22044643

  8. Assessing the impact of a Christmas advertisement campaign on Catalan wine preference using Choice Experiments.

    Science.gov (United States)

    Kallas, Zein; Escobar, Cristina; Gil, José Maria

    2012-02-01

    Our paper seeks to assess the impact of information and advertisement on consumers' preference for wines in special occasions (Christmas) in Catalonia (Spain). We apply the Choice Experiments method to study the relative importance of attributes that describe consumers' decision to purchase wine by using the Heteroskedastic Extreme Value (HEV) model. Data were obtained from two questionnaires applied to a pre and post spot samples formed by 299 and 400 individuals, respectively. Results suggest that the proposed spot does not affect the ranking of the preferred attributes, nevertheless this preference is heterogeneous. After advertising preferences scores have revealed significant differences. The relative importance of the "Catalan" wine has increased compared to the "Spanish" wine. The most preferred product is a Catalan wine made from the "Cabernet Sauvignon" variety. Wines that have been previously tasted by the consumer seem to be preferred over recommended or prestigious wines. However, advertising increases the relative importance of prestigious wines.

  9. Magnetic alignment in carps: evidence from the Czech christmas fish market.

    Directory of Open Access Journals (Sweden)

    Vlastimil Hart

    Full Text Available While magnetoreception in birds has been studied intensively, the literature on magnetoreception in bony fish, and particularly in non-migratory fish, is quite scarce. We examined alignment of common carps (Cyprinus carpio at traditional Christmas sale in the Czech Republic. The sample comprised measurements of the directional bearings in 14,537 individual fish, distributed among 80 large circular plastic tubs, at 25 localities in the Czech Republic, during 817 sampling sessions, on seven subsequent days in December 2011. We found that carps displayed a statistically highly significant spontaneous preference to align their bodies along the North-South axis. In the absence of any other common orientation cues which could explain this directional preference, we attribute the alignment of the fish to the geomagnetic field lines. It is apparent that the display of magnetic alignment is a simple experimental paradigm of great heuristic potential.

  10. Auggie Wren’s Christmas Story : signes visuels, sonores et verbaux

    Directory of Open Access Journals (Sweden)

    Chantal Lacourarie

    2012-05-01

    Full Text Available Voici un exemple d’activité alliant le visuel, le sonore et le verbal, le tout emballé dans un beau papier cadeau puisqu’il s’agit d’un conte de Noël : Auggie Wren’s Christmas Story. Le support est à la fois écrit puisque le conte est basé sur une nouvelle éponyme de Paul Auster publiée le jour de Noël 1990 dans le New York Times, et cinématographique du fait qu’un film intitulé Smoke et réalisé aux États-Unis par Wayne Wang en a été tiré en 1995. Le scénario est de Paul Auster et est interpr...

  11. Modular Tree Automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular r...

  12. Bronchi, Bronchial Tree, & Lungs

    Science.gov (United States)

    ... specific Modules Resources Archived Modules Updates Bronchi, Bronchial Tree, & Lungs Bronchi and Bronchial Tree In the mediastinum , at the level of the ... trachea. As the branching continues through the bronchial tree, the amount of hyaline cartilage in the walls ...

  13. Tree Tectonics

    Science.gov (United States)

    Vogt, Peter R.

    2004-09-01

    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).

  14. Healthy,Happy trees

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all this only if they are healthy.They must be well cared for to remain healthy.

  15. X-tree

    OpenAIRE

    Keim, Daniel A.; Bustos Cárdenas, Benjamin Eugenio; Berchtold, Stefan; Kriegel, Hans-Peter

    2008-01-01

    The X-tree (eXtended node tree) [1] is a spatial access method [2] that supports efficient query processing for high-dimensional data. It supports not only point data but also extended spatial data. The X-tree provides overlap-free split whenever it is possible without allowing the tree to degenerate; otherwise, the X-tree uses extended variable size directory nodes, so-called supernodes. The X-tree may be seen as a hybrid of a linear array-like and a hierarchical R-tree-like directory.

  16. ANDREWES'S CHRISTMAS FAIRY TALE: ATYPICAL THINKING ABOUT CANCER AETIOLOGY IN 1935.

    Science.gov (United States)

    Sankaran, Neeraja; van Helvoort, Ton

    2016-06-20

    This paper uses a short 'Christmas fairy-story for oncologists' sent by Christopher Andrewes with a 1935 letter to Peyton Rous as the centrepiece of a reflection on the state of knowledge and speculation about the viral aetiology of cancer in the 1930s. Although explicitly not intended for public circulation at the time, the fairy-story merits publication for its significance in the history of ideas about viruses, which are taken for granted today. Andrewes and Rous were prominent members of the international medical research community and yet faced strong resistance to their theory that viruses could cause such tumours as chicken sarcomas and rabbit papillomas. By looking at exchanges between these men among themselves and other proponents of their theories and with their oncologist detractors, we highlight an episode in the behind-the-scenes workings of medical science and show how informal correspondence helped keep alive a vital but then heterodox idea about the role of viruses in causing cancer.

  17. Fault tree handbook

    International Nuclear Information System (INIS)

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

  18. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  19. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  20. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    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.

  1. Christmas of Light in Gramado: a community cultural heritage promoting regional development in the Serra Gaúcha

    OpenAIRE

    Daniel Luciano Gevehr; Roger Pierre Vidal; Aline Nandi

    2014-01-01

    This study presents a conceptual revision on the event known as Natal Luz (Christmas of Lights), hosted in the city of Gramado – RS. This event has been officially considered part of the state of Rio Grande do Sul’s Cultural Heritage since 2008, officialized by the Law number 13.060. The aim is to analyze this event from its beginning to its present state, that is, from 1986 to 2013. We wished to take under consideration the impacts of globalization on the Cultural Heritage of our state. We h...

  2. Uniform random spanning trees

    OpenAIRE

    Pemantle, Robin

    2004-01-01

    There are several good reasons you might want to read about uniform spanning trees, one being that spanning trees are useful combinatorial objects. Not only are they fundamental in algebraic graph theory and combinatorial geometry, but they predate both of these subjects, having been used by Kirchoff in the study of resistor networks. This article addresses the question about spanning trees most natural to anyone in probability theory, namely what does a typical spanning tree look like?

  3. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....

  4. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    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…

  5. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  6. The Wish Tree Project

    Science.gov (United States)

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  7. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di erent problems that rely on contour trees can be solved in parallel with minimal communication.

  8. Trees in Lhasa

    Institute of Scientific and Technical Information of China (English)

    Degyi

    2008-01-01

    Trees are flourishing in Lhasa wherever the history exists. There is such a man. He has already been through cus-toms after his annual trek to Lhasa, which he has been doing for over twenty years in succession to visit his tree.Although he has been making this journey for so long,it is neither to visit friends or family,nor is it his hometown.It is a tree that is tied so profoundly to his heart.When the wind blows fiercely on the bare tree and winter snow falls,he stands be-fore the tree with tears of jo...

  9. Christmas of Light in Gramado: a community cultural heritage promoting regional development in the Serra Gaúcha

    Directory of Open Access Journals (Sweden)

    Daniel Luciano Gevehr

    2014-03-01

    Full Text Available This study presents a conceptual revision on the event known as Natal Luz (Christmas of Lights, hosted in the city of Gramado – RS. This event has been officially considered part of the state of Rio Grande do Sul’s Cultural Heritage since 2008, officialized by the Law number 13.060. The aim is to analyze this event from its beginning to its present state, that is, from 1986 to 2013. We wished to take under consideration the impacts of globalization on the Cultural Heritage of our state. We have based our analyzes, which is exploratory-descriptive, on the greatest Christmas-related event in Latin America by describing its formation process into Cultural Heritage. To do so, we have done bibliographical and documental research, which were the foundation for the establishment of the problem of our research. Through this approach, we have sought to understand the impacts of the tourism industry on the evolution of this local heritage, which was built and is currently lived by the whole community, into an event that is known worldwide.JEL-Code | L83; O18; R11.

  10. From gene trees to species trees II: Species tree inference in the deep coalescence model

    OpenAIRE

    Zhang, Louxin

    2010-01-01

    When gene copies are sampled from various species, the resulting gene tree might disagree with the containing species tree. The primary causes of gene tree and species tree discord include lineage sorting, horizontal gene transfer, and gene duplication and loss. Each of these events yields a different parsimony criterion for inferring the (containing) species tree from gene trees. With lineage sorting, species tree inference is to find the tree minimizing extra gene lineages that had to coexi...

  11. 75 FR 4384 - Pesticide Products; Registration Applications

    Science.gov (United States)

    2010-01-27

    ... weeds in turfgrass, ornamentals, nurseries, Christmas trees, landscape plantings, forestry, and... turfgrass, ornamentals, nurseries, Christmas trees, landscape plantings, forestry, and hardscapes in non..., Christmas trees, landscape plantings, forestry, hardscapes in non-crop areas, citrus fruits, pome...

  12. The Cosmic Christmas Ghost - Two Stunning Pictures of Young Stellar Clusters

    Science.gov (United States)

    2005-12-01

    Just like Charles Dickens' Christmas Carol takes us on a journey into past, present and future in the time of only one Christmas Eve, two of ESO' s telescopes captured various stages in the life of a star in a single image. ESO PR Photo 42a/05 shows the area surrounding the stellar cluster NGC 2467, located in the southern constellation of Puppis (" The Stern" ). With an age of a few million years at most, it is a very active stellar nursery, where new stars are born continuously from large clouds of dust and gas. The image, looking like a colourful cosmic ghost or a gigantic celestial Mandrill [1] , contains the open clusters Haffner 18 (centre) and Haffner 19 (middle right: it is located inside the smaller pink region - the lower eye of the Mandrill), as well as vast areas of ionised gas. The bright star at the centre of the largest pink region on the bottom of the image is HD 64315, a massive young star that is helping shaping the structure of the whole nebular region. ESO PR Photo 42a/05 was taken with the Wide-Field Imager camera at the 2.2m MPG/ESO telescope located at La Silla, in Chile. Another image of the central part of this area is shown as ESO PR Photo 42b/05. It was obtained with the FORS2 instrument at ESO' s Very Large Telescope on Cerro Paranal, also in Chile. ESO PR Photo 42b/05 zooms in on the open stellar cluster Haffner 18, perfectly illustrating three different stages of this process of star formation: In the centre of the picture, Haffner 18, a group of mature stars that have already dispersed their birth nebulae, represents the completed product or immediate past of the star formation process. Located at the bottom left of this cluster, a very young star, just come into existence and, still surrounded by its birth cocoon of gas, provides insight into the very present of star birth. Finally, the dust clouds towards the right corner of the image are active stellar nurseries that will produce more new stars in the future. Haffner 18 contains

  13. The valuative tree

    CERN Document Server

    Favre, Charles

    2004-01-01

    This volume is devoted to a beautiful object, called the valuative tree and designed as a powerful tool for the study of singularities in two complex dimensions. Its intricate yet manageable structure can be analyzed by both algebraic and geometric means. Many types of singularities, including those of curves, ideals, and plurisubharmonic functions, can be encoded in terms of positive measures on the valuative tree. The construction of these measures uses a natural tree Laplace operator of independent interest.

  14. Trees in renorming theory

    OpenAIRE

    Haydon, Richard

    1995-01-01

    Trees are very agreeable objects to work with, offering a diversity of behaviour within a structure that is sufficiently simple to admit precise analysis. Thus we are able to offer fairly satisfactory necessary and sufficient conditions on a tree $\\Upsilon $ for the existence of equivalent LUR or strictly convex norms on $\\C_0(\\Upsilon )$ and for norms with the Kadec Property. In particular, we show that for a {\\sl finitely branching} tree $\\Upsilon $ the space $\\C_0(\\Upsilon )$ admits a Kade...

  15. Generalized Binomial Trees

    OpenAIRE

    Jackwerth, Jens Carsten

    1996-01-01

    We consider the problem of consistently pricing new options given the prices of related options on the same stock. The Black-Scholes formula and standard binomial trees can only accommodate one related European option which then effectively specifies the volatility parameter. Implied binomial trees can accommodate only related European options with the same time-to-expiration.The generalized binomial trees introduced here can accommodate any kind of related options (European, American, or exo...

  16. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Pantazos, Kostas;

    2015-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D2-tree). The D2-tree compares favorably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers......-balancing scheme of elements into nodes is deterministic and general enough to be applied to other hierarchical tree-based overlays. This load-balancing mechanism is based on an innovative lazy weight-balancing mechanism, which is interesting in its own right....

  17. The tree BVOC index

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.R., E-mail: jrsimpson@ucdavis.edu [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States); McPherson, E.G. [U.S. Forest Service, Pacific Southwest Research Station, Urban Ecosystems and Processes, 1731 Research Park Drive, Davis, CA 95616 (United States)

    2011-08-15

    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. - Highlights: > A Tree BVOC index based on reduced emissions from low emitting trees is described. > An example illustrates use of the index as an implementation and monitoring tool. > This index could be useful for including urban trees in air quality mitigation plans. - A tree BVOC index is presented that calculates reduced BVOC emissions from planting lower-emitting urban tree species that has potential application for SIP compliance.

  18. Symmetric M-tree

    CERN Document Server

    Sexton, Alan P

    2010-01-01

    The M-tree is a paged, dynamically balanced metric access method that responds gracefully to the insertion of new objects. To date, no algorithm has been published for the corresponding Delete operation. We believe this to be non-trivial because of the design of the M-tree's Insert algorithm. We propose a modification to Insert that overcomes this problem and give the corresponding Delete algorithm. The performance of the tree is comparable to the M-tree and offers additional benefits in terms of supported operations, which we briefly discuss.

  19. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  20. 78 FR 27935 - Submission for OMB Review; Comment Request

    Science.gov (United States)

    2013-05-13

    ... OMB control number. National Agricultural Statistics Service Title: Nursery and Christmas Tree... Christmas tree production data and nursery and floriculture chemical use data will be used by NASS,...

  1. Searching informed game trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1992-01-01

    textabstractWell-known algorithms for the evaluation of the minimax function in game trees are alpha-beta and SSS*. An improved version of SSS* is SSS-2. All these algorithms don't use any heuristic information on the game tree. In this paper the use of heuristic information is introduced into the a

  2. Structural Equation Model Trees

    Science.gov (United States)

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

    2013-01-01

    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…

  3. Matching Subsequences in Trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2009-01-01

    Given two rooted, labeled trees P and T the tree path subsequence problem is to determine which paths in P are subsequences of which paths in T. Here a path begins at the root and ends at a leaf. In this paper we propose this problem as a useful query primitive for XML data, and provide new...

  4. Pruning peach trees

    OpenAIRE

    Sagers, Larry A.

    1988-01-01

    Discusses the importance of annual pruning to produce high yield and quality of peaches. Advises that the successful pruner should understand how the trees grow, and how the trees respond to pruning. Also cautions that improper pruning will lower yield and quality of fruit.

  5. Tree nut oils

    Science.gov (United States)

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

  6. Early Holocene fauna from a new subfossil site: A first assessment from Christmas River, south central Madagascar

    Directory of Open Access Journals (Sweden)

    Patricia C. Wright

    2012-06-01

    Full Text Available We report on faunal remains recovered during recent explo­rations at ‘Christmas River’, the only subfossil locality known from Madagascar’s south central plateau. Recovered remains of several extinct taxa date to approximately 10,000 14C years before present (BP, including crocodiles, tortoises, the elephant bird Aepyornis, the carnivoran Cryptoprocta spelea, the lemurs Archaeolemur majori, Pachylemur insignis, and Megaladapis edwardsi, and abundant remains of the dwarf hippopotamus, Hippopotamus lemerlei. The presence of southern – limited, forest – dependent species at Christmas River supports the hypothesis that forest once extended, perhaps discontinu­ously, across the central highlands towards the west. One theory is that sites in the north central highlands, which are higher in elevation, maintained more mesic conditions during Plio–Quaternary climate shifts than those of the lower elevation sites of the south central highlands. Thus, elevation above sea level may have acted as a filter that limited species dispersal across the island in the past. Such a scenario would explain the distinction between more humid, higher elevation, northern highland subfossil communities versus more arid, lower eleva­tion, southern subfossil communities. Continued exploration at Christmas River thus provides a remarkable opportunity for deciphering ecological changes that have taken place in south central Madagascar during the Holocene. RÉSUMÉMadagascar est reconnue comme l’une des régions les plus sensibles du monde en ce qui concerne les menaces pesant sur sa biodiversité, et cela à cause de niveaux d’endémisme inégalés, d’une diversité variée et d’un impact humain important sur l’environnement. Suite à la colonisation par l’Homme il y a plus de 2000 ans, des extinctions de masse de la faune et un important recul forestier ont eu lieu en laissant des marques sur les écosystèmes modernes qui sont dans un état de

  7. PaisleyTrees: A Size-Invariant Tree Visualization

    Directory of Open Access Journals (Sweden)

    Katayoon Etemad

    2014-10-01

    Full Text Available Squeezing large tree structures into suitable visualizations has been a perennial problem. In response to this challenge, we present PaisleyTrees, a size-invariant tree visualization. PaisleyTrees integrate node-of-interest focus with tree-cut presentations to support rapid tree navigation without resorting to zooming and panning. This visualization offers the ability to work with trees of arbitrary depth and breadth, and maintains legibility for displayed elements. These advantages are achieved by using a hybrid layout, inspired by traditional Paisley patterns, that combines node-link, nested and djacency-based tree layout techniques, and offers both depth and breadth elision.

  8. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  9. Phylogenetic trees in bioinformatics

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom L [Los Alamos National Laboratory

    2008-01-01

    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.

  10. Second space Christmas for ESA: Huygens to begin its final journey to Titan/ Media activities.

    Science.gov (United States)

    2004-12-01

    the morning of 25 December at about 05:08 CET. Since the Cassini orbiter will have to achieve precise pointing for the release, there will be no real-time telemetry available until it turns back its main antenna toward Earth and beams the recorded data of the release. It will take over an hour (67 min) for the signals to reach us on Earth. The final data confirming the separation will be available later on Christmas Day. After release, Huygens will move away from Cassini at a speed of about 35 cm per second and, to keep on track, will spin on its axis, making about 7 revolutions a minute. Huygens will not communicate with Cassini for the whole period until after deployment of the main parachute following entry into Titan’s atmosphere. On 28 December Cassini will then manoeuvre off collision course to resume its mission and prepare itself to receive Huygens data, which it will record for later playback to Earth. Huygens will remain dormant until a few hours before its arrival at Titan on 14 January. The entry into the atmosphere is set for 11:15 CET. Huygens is planned to complete its descent in about two hours and 15 minutes, beaming back its science data to the Cassini orbiter for replay to Earth later in the afternoon. If Huygens, which is designed as an atmospheric probe rather than a lander, survives touchdown on the surface, it could deliver up to 2 hours of bonus data before the link with Cassini is lost. Direct radio signals from Huygens will reach Earth after 67 minutes of interplanetary travel at the speed of light. An experiment has been set up by radio scientists that will use an array of radio telescopes around the Pacific to attempt to detect a faint tone from Huygens. If successful, early detection is not expected before around 11:30 CET. The European Space Agency owns and manages the Huygens probe and is in charge of operations of the probe from its control centre in Darmstadt, Germany. NASA's Jet Propulsion Laboratory in Pasadena, California

  11. Compatible spanning trees

    OpenAIRE

    Garcia Olaverri, Alfredo Martin; Huemer, Clemens; Hurtado Díaz, Fernando Alfredo; Tejel Altarriba, Francisco Javier

    2014-01-01

    Two plane geometric graphs are said to be compatible when their union is a plane geometric graph. Let S be a set of n points in the Euclidean plane in general position and let T be any given plane geometric spanning tree of S. In this work, we study the problem of finding a second plane geometric tree T' spanning S, such that is compatible with T and shares the minimum number of edges with T. We prove that there is always a compatible plane geometric tree T' having at most #n - 3#/4 edges in ...

  12. LIMSUP DEVIATIONS ON TREES

    Institute of Scientific and Technical Information of China (English)

    Fan Aihua

    2004-01-01

    The vertices of an infinite locally finite tree T are labelled by a collection of i.i.d. real random variables {Xσ}σ∈T which defines a tree indexed walk Sσ = ∑θ<r≤σXr. We introduce and study the oscillations of the walk:Exact Hausdorff dimension of the set of such ξ 's is calculated. An application is given to study the local variation of Brownian motion. A general limsup deviation problem on trees is also studied.

  13. The gravity apple tree

    Science.gov (United States)

    Espinosa Aldama, Mariana

    2015-04-01

    The gravity apple tree is a genealogical tree of the gravitation theories developed during the past century. The graphic representation is full of information such as guides in heuristic principles, names of main proponents, dates and references for original articles (See under Supplementary Data for the graphic representation). This visual presentation and its particular classification allows a quick synthetic view for a plurality of theories, many of them well validated in the Solar System domain. Its diachronic structure organizes information in a shape of a tree following similarities through a formal concept analysis. It can be used for educational purposes or as a tool for philosophical discussion.

  14. Tree-growth analyses to estimate tree species' drought tolerance

    NARCIS (Netherlands)

    Eilmann, B.; Rigling, A.

    2012-01-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree specie

  15. A Characterization of the average tree solution for tree games

    OpenAIRE

    Debasis Mishra; Dolf Talman

    2009-01-01

    For the class of tree games, a new solution called the average tree solution has been proposed recently. We provide a characterization of this solution. This characterization underlines an important difference, in terms of symmetric treatment of the agents, between the average tree solution and the Myerson value for the class of tree games.

  16. ControlTree: Navigating and Selecting in a Large Tree

    OpenAIRE

    Appert, Caroline; Fekete, Jean-Daniel

    2006-01-01

    International audience We introduce ControlTree, a novel interface using crossing interaction to navigate and select nodes in a large tree. ControlTree combines an optimized dynamic layout with interaction features to quickly reach a node in a node-link tree representation.

  17. Tell me if you - on Christmas supper - serve Turkey or Chester, and I will tell who you are.” Thoughts about identity, tradition, authenticity, trust and distinction.

    Directory of Open Access Journals (Sweden)

    Maria Elisabeth Goidanich

    2009-01-01

    Full Text Available It may be said that commerce has a high sales volume index during Christmas season and this period is of intense consumption of all kinds of goods. It is also full of significance. This article analyses Christmas supper and its significance for thirty-six to forty-seven years old mid class women, using as research object the consumption of Chester and/or Turkey (noble birds. A comparative analysis of both kinds of birds is traced, in which the consumption is a reflection of cultural and economical globalization. Using an interdisciplinary point of view, it is explored the relation between the concepts of: identity, tradition, authenticity, trust and distinction; and the consumption behavior and imaginary universe of these women. The results of an empirical research made in December of 2007 and also data collected at supermarket establishments in Florianópolis are presented for such objective.

  18. Tree-like tableaux

    CERN Document Server

    Aval, Jean-Christophe; Nadeau, Philippe

    2011-01-01

    In this work we introduce and study tree-like tableaux, which are certain fillings of Ferrers diagrams in simple bijection with permutation tableaux and alternative tableaux. We exhibit an elementary insertion procedure on our tableaux which gives a clear proof that tableaux of size n are counted by n!, and which moreover respects most of the well-known statistics studied originally on alternative and permutation tableaux. Our insertion procedure allows to define in particular two simple new bijections between tree-like tableaux and permutations: the first one is conceived specifically to respect the generalized pattern 2-31, while the second one respects the underlying tree of a tree-like tableau.

  19. The tree BVOC index.

    Science.gov (United States)

    Simpson, J R; McPherson, E G

    2011-01-01

    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

  20. Loops and trees

    Science.gov (United States)

    Caron-Huot, S.

    2011-05-01

    We investigate relations between loop and tree amplitudes in quantum field theory that involve putting on-shell some loop propagators. This generalizes the so-called Feynman tree theorem which is satisfied at 1-loop. Exploiting retarded boundary conditions, we give a generalization to ℓ-loop expressing the loops as integrals over the on-shell phase space of exactly ℓ particles. We argue that the corresponding integrand for ℓ > 2 does not involve the forward limit of any physical tree amplitude, except in planar gauge theories. In that case we explicitly construct the relevant physical amplitude. Beyond the planar limit, abandoning direct integral representations, we propose that loops continue to be determined implicitly by the forward limit of physical connected trees, and we formulate a precise conjecture along this line. Finally, we set up technology to compute forward amplitudes in supersymmetric theories, in which specific simplifications occur.

  1. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number...... of available processor cores compared to its sequential counterpart, thereby taking full advantage of multicore parallelism. The parallel buffer tree is a search tree data structure that supports the batched parallel processing of a sequence of N insertions, deletions, membership queries, and range queries...... in the optimal OhOf(psortN + K/PB) parallel I/O complexity, where K is the size of the output reported in the process and psortN is the parallel I/O complexity of sorting N elements using P processors....

  2. NLCD 2001 - Tree Canopy

    Data.gov (United States)

    Minnesota Department of Natural Resources — The National Land Cover Database 2001 tree canopy layer for Minnesota (mapping zones 39-42, 50-51) was produced through a cooperative project conducted by the...

  3. Robustness of a routing tree for the Push Tree Problem

    OpenAIRE

    Havet, Frédéric

    2002-01-01

    The Push Tree problem contains elements from both the Steiner Tree and Shortest Path problem. It deals with the trade-offs between the push and pull mechanism used in information distribution and retrieval. In , a two step approach for the Push Tree Problem was proposed. In the first step, a «good» spanning tree (called routing tree) is constructed and then the problem is solved in this particular tree. Finding a routing tree is NP-hard but the second step may be performed easily, thus the id...

  4. Type extension trees

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We introduce type extension trees as a formal representation language for complex combinatorial features of relational data. Based on a very simple syntax this language provides a unified framework for expressing features as diverse as embedded subgraphs on the one hand, and marginal counts...... of attribute values on the other. We show by various examples how many existing relational data mining techniques can be expressed as the problem of constructing a type extension tree and a discriminant function....

  5. Information flow on trees

    OpenAIRE

    Mossel, Elchanan; Peres, Yuval

    2003-01-01

    Consider a tree network $T$, where each edge acts as an independent copy of a given channel $M$, and information is propagated from the root. For which $T$ and $M$ does the configuration obtained at level $n$ of $T$ typically contain significant information on the root variable? This problem arose independently in biology, information theory and statistical physics. ¶ For all $b$, we construct a channel for which the variable at the root of the break $b$-ary tree is...

  6. Urban tree mortality

    OpenAIRE

    Roman, Lara Angelica

    2013-01-01

    Urban forests have aesthetic, environmental, human health, and economic benefits that motivate tree planting programs. Realizing these benefits depends on tree survival. Cost-benefit analyses for urban forest ecosystem services are sensitive to mortality rate assumptions and associated population projections. However, long-term mortality data is needed to assess the accuracy of these assumptions. Analytical tools from demography, such as life tables, mortality curves, and survival analysis, c...

  7. Tree Improvement Glossary

    DEFF Research Database (Denmark)

    Schmidt, Lars Holger

    Forest tree improvement encompasses a number of scientific and technical areas like floral-, reproductive- and micro-biology, genetics breeding methods and strategies, propagation, gene conservation, data analysis and statistics, each area with a comprehensive terminology. The terms selected...... for definition here are those most frequently used in tree improvement literature. Clonal propagation is included in the view of the great expansion of that field as a means of mass multiplication of improved material....

  8. HOLIDAY SEASON Spring Festival is China's biggest celebration,but foreign holidays such as Christmas and Valentine's Day are making inroads

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As China opens to the world, Chinese people are embracing the Western world's holidays. Christmas, Valentine's Day and Halloween are all growing in popularity, as the commercial aspects of these celebrations find an audience. Young people say they feel increasingly detached from traditions associated with age-old Chinese festivals, such as Spring Festival, which starts January 29 this year and marks the lunar New Year. But Spring Festival isn't going anywhere yet, and this week the country heads home en ...

  9. Hydrologic, water-quality, and sediment-quality data for the Christmas Bay system, Brazoria County, Texas, February 1999-March 2000

    Science.gov (United States)

    East, Jeffery W.

    2002-01-01

    The Christmas Bay system is a group of three small secondary bays (Christmas, Bastrop, and Drum Bays) at the southwestern end of the Galveston Bay estuarine system in Brazoria County, Texas. During February 1999-March 2000, hydrologic, water-quality, and sediment-quality data were collected from each of the three bays to establish baseline conditions. Gage-height fluctuations closely matched open-water tidal fluctuations. Rainfall during February 1999-February 2000 was about 20 percent below the annual average. Specific conductance, pH, water temperature, and dissolved oxygen monitored at 30-minute intervals in Christmas Bay for 13 months showed seasonal variations typical of monitoring stations on the Texas Gulf Coast. Prevailing winds were from the southeast. Monthly water-quality sampling for 13 months showed that in each of the three bays concentrations of major ions were small, and most nutrient concentrations were at or less than minimum reporting levels; indicator bacteria counts were consistently higher in samples collected from Drum Bay. Several trace elements (sampled twice) were detected in small concentrations. The only organochlorine pesticides (sampled once) that were greater than minimum reporting levels were atrazine, deethylatrazine, metolachlor, and simazine. During February 29-March 29, 2000, three semipermeable membrane devices were deployed at the Christmas Bay monitoring station. Seven of 77 semivolatile organic compounds analyzed in the lipids from the devices were detected in minute amounts. Analyses of surficial bed sediment sampled once in each of the three bays yielded detections of a number of semivolatile organic compounds; all concentrations were less than 10 micrograms per liter and much less than the respective benchmark concentration for those compounds that have had a benchmark concentration established for the protection of aquatic life.

  10. Tree felling 2014

    CERN Multimedia

    2014-01-01

    With a view to creating new landscapes and making its population of trees safer and healthier, this winter CERN will complete the tree-felling campaign started in 2010.   Tree felling will take place between 15 and 22 November on the Swiss part of the Meyrin site. This work is being carried out above all for safety reasons. The trees to be cut down are at risk of falling as they are too old and too tall to withstand the wind. In addition, the roots of poplar trees are very powerful and spread widely, potentially damaging underground networks, pavements and roadways. Compensatory tree planting campaigns will take place in the future, subject to the availability of funding, with the aim of creating coherent landscapes while also respecting the functional constraints of the site. These matters are being considered in close collaboration with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP). GS-SE Group

  11. Geometric Decision Tree

    CERN Document Server

    Manwani, Naresh

    2010-01-01

    In this paper we present a new algorithm for learning oblique decision trees. Most of the current decision tree algorithms rely on impurity measures to assess the goodness of hyperplanes at each node while learning a decision tree in a top-down fashion. These impurity measures do not properly capture the geometric structures in the data. Motivated by this, our algorithm uses a strategy to assess the hyperplanes in such a way that the geometric structure in the data is taken into account. At each node of the decision tree, we find the clustering hyperplanes for both the classes and use their angle bisectors as the split rule at that node. We show through empirical studies that this idea leads to small decision trees and better performance. We also present some analysis to show that the angle bisectors of clustering hyperplanes that we use as the split rules at each node, are solutions of an interesting optimization problem and hence argue that this is a principled method of learning a decision tree.

  12. Statistical Analysis for VHF Radar Parameters at SÃO LUÍS, Jicamarca and Christmas Island Equatorial Stations

    Science.gov (United States)

    de la cruz cueva, R. Y.; Paula, E. R.; Kherani, E. A.

    2013-05-01

    Equatorial Spread F (ESF) is a manifestation of ionospheric interchange instabilities in the nighttime equatorial F region. These instabilities generate plasma density irregularities with scale sizes ranging from kilometers to thousands of kilometers. The irregularities can be detected from varieties of instruments such as digisonde, coherent and incoherent scatter radars, in situ space probes, and airglow photometers. In the present study, statistics of various aspects of spread F occurrence are presented from HF/VHF radar and incoherent scatter radar located at three equatorial stations: Christmas Island (2oN, 202.6oE, 2.9oN dip latitude, VHF radar), São Luís (2.59oS, 315.8oE, 0.5oS dip latitude, HF radar) and Jicamarca (12oS, 283.1oE, 0.6oN dip latitude, ISR). The radar parameters presented here are the onset altitude and onset time of the bottom-type and plume, and the peak altitude of the plume which are known to be associated with the spread F occurrence characteristics. The study reveals novel features namely, seasonal and solar flux dependence of spread F occurrence over Christmas island /São Luís, and longitudinal dependence of spread F occurrence characteristics from these three stations based on the chosen parameters. The importance of this work lies in the radar parameter empirical model developed combining statistical analysis of three equatorial and longitudinally separated stations, which is important to study the irregularity generation mechanisms, for space weather forecasting and nowcasting programs, and improving scintillation warning models. These parameters show generally linear correlation with solar flux index (F10.7 cm) and variation with season and magnetic declination angle. The fit correlation with F10.7cm is shown as useful information to implement one spread-F development empirical model based on small scale irregularities detected by VHF radars.

  13. Covering R-trees

    CERN Document Server

    Berestovskii, V N

    2007-01-01

    We show that every inner metric space X is the metric quotient of a complete R-tree via a free isometric action, which we call the covering R-tree of X. The quotient mapping is a weak submetry (hence, open) and light. In the case of compact 1-dimensional geodesic space X, the free isometric action is via a subgroup of the fundamental group of X. In particular, the Sierpin'ski gasket and carpet, and the Menger sponge all have the same covering R-tree, which is complete and has at each point valency equal to the continuum. This latter R-tree is of particular interest because it is "universal" in at least two senses: First, every R-tree of valency at most the continuum can be isometrically embedded in it. Second, every Peano continuum is the image of it via an open light mapping. We provide a sketch of our previous construction of the uniform universal cover in the special case of inner metric spaces, the properties of which are used in the proof.

  14. Steiner trees in industry

    CERN Document Server

    Du, Ding-Zhu

    2001-01-01

    This book is a collection of articles studying various Steiner tree prob­ lems with applications in industries, such as the design of electronic cir­ cuits, computer networking, telecommunication, and perfect phylogeny. The Steiner tree problem was initiated in the Euclidean plane. Given a set of points in the Euclidean plane, the shortest network interconnect­ ing the points in the set is called the Steiner minimum tree. The Steiner minimum tree may contain some vertices which are not the given points. Those vertices are called Steiner points while the given points are called terminals. The shortest network for three terminals was first studied by Fermat (1601-1665). Fermat proposed the problem of finding a point to minimize the total distance from it to three terminals in the Euclidean plane. The direct generalization is to find a point to minimize the total distance from it to n terminals, which is still called the Fermat problem today. The Steiner minimum tree problem is an indirect generalization. Sch...

  15. The inference of gene trees with species trees.

    Science.gov (United States)

    Szöllősi, Gergely J; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

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

  16. Combining Breeding Bird Survey and Christmas Bird Count data to evaluate seasonal components of population change in Northern Bobwhite

    Science.gov (United States)

    Link, W.A.; Sauer, J.R.; Niven, D.K.

    2008-01-01

    Annual surveys of wildlife populations provide information about annual rates of change in populations but provide no information about when such changes occur. However, by combining data from 2 annual surveys, conducted in different parts of the year, seasonal components of population change can be estimated. We describe a hierarchical model for simultaneous analysis of 2 continent-scale monitoring programs. The Christmas Bird Count is an early winter survey, whereas the North American Breeding Bird Survey is conducted in June. Combining information from these surveys permits estimation of seasonal population variance components and improves estimation of long-term population trends. The composite analysis also controls for survey-specific sampling effects. We applied the model to estimation of population change in northern bobwhites (Colinus virginianus). Over the interval 1969?2004, bobwhite populations declined, with trend estimate of -3.56% per year (95% CI = [-3.80%, -3.32%]) in the surveyed portion of their range. Our analysis of seasonal population variance components indicated that northern bobwhite populations changed more in the winter and spring portion of the year than in the summer and fall portion of the year.

  17. Sweet Christmas: Do overweight and obese children associate special events more frequently with food than normal weight children?

    Science.gov (United States)

    Martijn, Carolien; Pasch, Sophie; Roefs, Anne

    2016-01-01

    This study examined children's spontaneous associations of special events with food. Children in primary education (N = 111, age between 10 and 13 years) at a school in Germany wrote down their first five associations with five special or festive events (Christmas, holidays, weekend, carnival and birthday). After completing the free-word association test, they were offered a choice between a candy and a toy. Finally, their body mass index (BMI) was measured. The first prediction was that overweight and obese children would associate special events more often with food than normal weight and leaner children. The second prediction was that choice for a candy would be predicted by a higher number of food-related associations. The first hypothesis was not supported: BMI was negatively related to number of food-related associations (the lower the BMI, the more food-related associations). The second hypothesis was also not supported: There was no relation between number of food-related associations and choice for a candy or toy. A possible explanation for the finding that leaner children reported more food-related associations is that for them specific sweets and snack food are more exclusively connected to special occasions than for overweight children. Speculatively, this may be the result of differences in food parenting styles between parents of heavier and leaner children. Parents of leaner children often have a more restrictive style, i.e., reserving specific foods for specific, relatively rare occasions whereas parents of overweight children adopt more liberal food rules.

  18. Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle.

    Science.gov (United States)

    Hennicke, Janos C; James, David J; Weimerskirch, Henri

    2015-01-01

    In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi) were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas) allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.

  19. Effects of temperature and irradiance level on carbohydrate content and keeping quality of Christmas begonia (Begonia x cheimantha Everett)

    International Nuclear Information System (INIS)

    The carbohydrate content and keeping quality of Christmas begonia were determined in a factorial experiment in which the plants were subjected to irradiance levels of 15, 30 and 60 μmol m−2 s−1 and to temperature levels of 15, 18 and 21°C for the last part of the growing period. This period lasted from 11 to 24 days depending on irradiance level and temperature. The contents of sucrose, glucose and starch were determined at the marketing stage. The keeping quality of the plants was determined after 3 weeks in a simulated interior climate. Increase in temperature and irradiance level both enhanced the development of flowers during the later part of the growing period. The temperature did not have any effect on plant quality at the marketing stage nor on the carbohydrate content, but high temperature caused an increase in flower stem height after 3 weeks in interior climate. Increase in irradiance level caused a significant increase in the content of starch at the marketing stage. Percent increase in new flowers during the interior holding period was highly correlated with the contents of sucrose and starch in the inflorescences and with the content of starch in the leaves. A large starch pool in the inflorescences and in the leaves at the marketing stage reduced the abscission rate during the interior holding period. (author)

  20. Generic Ising trees

    DEFF Research Database (Denmark)

    Durhuus, Bergfinnur Jøgvan; Napolitano, George Maria

    2012-01-01

    The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove that they......The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove...... that they exhibit no spontaneous magnetization. Furthermore, the values of the Hausdorff and spectral dimensions of the underlying trees are calculated and found to be, respectively,¯dh =2 and¯ds = 4/3....

  1. Active flows on trees

    CERN Document Server

    Forrow, Aden; Dunkel, Jörn

    2016-01-01

    Coherent, large scale dynamics in many nonequilibrium physical, biological, or information transport networks are driven by small-scale local energy input. We introduce and explore a generic model for compressible active flows on tree networks. In contrast to thermally-driven systems, active friction selects discrete states with only a small number of oscillation modes activated at distinct fixed amplitudes. This state selection interacts with graph topology to produce different localized dynamical time scales in separate regions of large networks. Using perturbation theory, we systematically predict the stationary states of noisy networks and find good agreement with a Bayesian state estimation based on a hidden Markov model applied to simulated time series data on binary trees. While the number of stable states per tree scales exponentially with the number of edges, the mean number of activated modes in each state averages $\\sim 1/4$ the number of edges. More broadly, these results suggest that the macrosco...

  2. The gene tree delusion.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  3. The gene tree delusion.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  4. Tree-string duality

    International Nuclear Information System (INIS)

    After the termination of perturbative QCD tree evolution, colourless clusters are formed. Similarly, after the first generation cuts in the (classical) Artru-Mennessier string model, disconnected lengths of string result. The mass spectra of clusters and first generation strings are similar, and the similarity extends to the rapidity distributions as a function of mass. (author)

  5. A Universal Phylogenetic Tree.

    Science.gov (United States)

    Offner, Susan

    2001-01-01

    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)

  6. The Sacred Tree.

    Science.gov (United States)

    Lethbridge Univ. (Alberta).

    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"…

  7. Multiscale singularity trees

    DEFF Research Database (Denmark)

    Somchaipeng, Kerawit; Sporring, Jon; Johansen, Peter;

    2007-01-01

    We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state-of-theart methods. We conclude that the computational complexi...

  8. A Suffix Tree Or Not a Suffix Tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    , in particular we do not require that S ends with a unique symbol. This corresponds to considering the more general definition of implicit or extended suffix trees. Such general suffix trees have many applications and are for example needed to allow efficient updates when suffix trees are built online. We prove...

  9. Tree Formation Using Coordinate Method

    Directory of Open Access Journals (Sweden)

    Monika Choudhary

    2015-06-01

    Full Text Available In this paper we are introducing a new method of tree formation, we propose a coordinate based method by which we can store and access tree structures. As we know in NLP, parsing is the most important module. The output of this module is generally parsed trees. Currently, TAG (Tree Adjoining Grammar is widely used grammar due to its linguistic and formal nature. It is simply tree generating system. The unit structure used in TAG is structured trees. So we used our new method to store trees where we worked on English to Hindi language. We worked on different sentences from English to Hindi, our method is the easiest way to manipulate tree. We have implemented within small corpus and for finite number of structures and further can be extended in future.

  10. Tree Transduction Tools for Cdec

    Directory of Open Access Journals (Sweden)

    Austin Matthews

    2014-09-01

    Full Text Available We describe a collection of open source tools for learning tree-to-string and tree-to-tree transducers and the extensions to the cdec decoder that enable translation with these. Our modular, easy-to-extend tools extract rules from trees or forests aligned to strings and trees subject to different structural constraints. A fast, multithreaded implementation of the Cohn and Blunsom (2009 model for extracting compact tree-to-string rules is also included. The implementation of the tree composition algorithm used by cdec is described, and translation quality and decoding time results are presented. Our experimental results add to the body of evidence suggesting that tree transducers are a compelling option for translation, particularly when decoding speed and translation model size are important.

  11. Visual perception of tree forms

    Energy Technology Data Exchange (ETDEWEB)

    Muederrisoglu, Haldun; Eroglu, Engin; OEzkan, Suekran; Ak, Kivanc [Department of Landscape Architecture, Faculty of Forestry, Abant Izzet Baysal University, 81000, Duzce (Turkey)

    2006-06-15

    This study, made in the cities of Adapazari, Duzce, and Bolu, has three fundamental goals. The first one is the evaluation of visual quality and strength of each tree form, second is the determination of visual quality and strength of different tree forms next to each other, and the third goal of this study is determining the effects of personal characteristics to the perception of tree forms. To reach these three goals the semantic differential method was used to evaluate graphical visions of tree forms. According to the findings, trees with pyramid forms have the most effective visual quality and strength. Pyramid-formed tree combinations have higher visual quality and strength than mixed combinations do. At the same time personal characteristics are effective on the visual perception of tree forms. A strong relationship between the amount of area per person in the cities the participants live in and their visual perception of tree forms has been found. (author)

  12. Learning Stochastic Tree Edit Distance

    OpenAIRE

    Bernard, Marc; Habrard, Amaury; Sebban, Marc

    2006-01-01

    Trees provide a suited structural representation to deal with complex tasks such as web information extraction, RNA secondary structure prediction, or conversion of tree structured documents. In this context, many applications require the calculation of similarities between tree pairs. The most studied distance is likely the tree edit distance for which improvements in terms of complexity have been achieved during the last decade. However, this classic edit distance usually uses a priori fixe...

  13. Connected searching of weighted trees

    CERN Document Server

    Dereniowski, Dariusz

    2010-01-01

    In this paper we consider the problem of connected edge searching of weighted trees. It is shown that there exists a polynomial-time algorithm for finding optimal connected search strategy for bounded degree trees with arbitrary weights on the edges and vertices of the tree. The problem is NP-complete for general node-weighted trees (the weight of each edge is 1).

  14. Adjustable Chain Trees for Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Fonseca, Rasmus

    2012-01-01

    A chain tree is a data structure for changing protein conformations. It enables very fast detection of clashes and free energy potential calculations. A modified version of chain trees that adjust themselves to the changing conformations of folding proteins is introduced. This results in much...... tighter bounding volume hierarchies and therefore fewer intersection checks. Computational results indicate that the efficiency of the adjustable chain trees is significantly improved compared to the traditional chain trees....

  15. A Class of Graceful Trees

    Institute of Scientific and Technical Information of China (English)

    孟凡洪; 苏耕; 杨继

    2000-01-01

    The present paper shows the coordinates of a tree and its vertices, defines a kind of Trees with Odd-Number Radiant Type (TONRT), deals with the gracefulness of TONRT by using the edge-moving theorem, and uses graceful TONRT to construct another class of graceful trees.

  16. The Hopi Fruit Tree Book.

    Science.gov (United States)

    Nyhuis, Jane

    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…

  17. Respiratory, acid-base, and metabolic responses of the Christmas Island blue crab, Cardisoma hirtipes (Dana), during simulated environmental conditions.

    Science.gov (United States)

    Dela-Cruz, J; Morris, S

    1997-01-01

    The dependency of the Christmas Island blue crab, Cardisoma hirtipes, on fresh water for respiratory gas exchange and transport was investigated in laboratory simulations. The gas exchange rates of air-breathing C. hirtipes were similar to those of other land crabs but decreased to 20% in submerged crabs. Crabs with access to air maintained arterial and pulmonary O2 content (CO2) and partial pressure (PO2), while in submerged crabs the PO2 and CO2 rapidly decreased (by 50%). There was no anaerobiosis, but haemolymph glucose concentration and cardiac output decreased when crabs were submersed, which suggests a hypometabolic state. Submersion induced a metabolic rather than a respiratory alkalosis, and since respiratory gas exchange was low, CO2 excretion to water was unimportant. Cardisoma hirtipes haemocyanin (Hc) has high O2 affinity but low pH sensitivity, which facilitates O2 uptake from hypoxic environments. The high Hc-O2 affinity supports O2 loading but may prevent access to a venous O2 reserve. Calcium, magnesium, and urate, but not L-lactate, were effectors of Hc-O2 affinity. In submerged crabs increased circulating urate maintained haemolymph O2 content. The CO2 capacitance and nonbicarbonate buffering of the haemolymph were relatively low. A significant Haldane effect seemed important for CO2 excretion but would require CO2 and O2 exchange to occur at the same organ (gills or lungs). Submersion interferes with respiration and is not needed for haemolymph acid-base balance; thus; C. hirtipes is an air-breathing crab.

  18. Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle.

    Directory of Open Access Journals (Sweden)

    Janos C Hennicke

    Full Text Available In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.

  19. Sweet Christmas: Do overweight and obese children associate special events more frequently with food than normal weight children?

    Science.gov (United States)

    Martijn, Carolien; Pasch, Sophie; Roefs, Anne

    2016-01-01

    This study examined children's spontaneous associations of special events with food. Children in primary education (N = 111, age between 10 and 13 years) at a school in Germany wrote down their first five associations with five special or festive events (Christmas, holidays, weekend, carnival and birthday). After completing the free-word association test, they were offered a choice between a candy and a toy. Finally, their body mass index (BMI) was measured. The first prediction was that overweight and obese children would associate special events more often with food than normal weight and leaner children. The second prediction was that choice for a candy would be predicted by a higher number of food-related associations. The first hypothesis was not supported: BMI was negatively related to number of food-related associations (the lower the BMI, the more food-related associations). The second hypothesis was also not supported: There was no relation between number of food-related associations and choice for a candy or toy. A possible explanation for the finding that leaner children reported more food-related associations is that for them specific sweets and snack food are more exclusively connected to special occasions than for overweight children. Speculatively, this may be the result of differences in food parenting styles between parents of heavier and leaner children. Parents of leaner children often have a more restrictive style, i.e., reserving specific foods for specific, relatively rare occasions whereas parents of overweight children adopt more liberal food rules. PMID:26463017

  20. PoInTree: A Polar and Interactive Phylogenetic Tree

    Institute of Scientific and Technical Information of China (English)

    Carreras Marco; Gianti Eleonora; Sartori Luca; Plyte Simon Edward; Isacchi Antonella; Bosotti Roberta

    2005-01-01

    PoInTree (Polar and Innteractive Tree) is an application that allows to build, visualize, and customize phylogenetic trees in a polar, interactive, and highly flexible view. It takes as input a FASTA file or multiple alignment formats. Phylogenetic tree calculation is based on a sequence distance method and utilizes the Neighbor Joining (NJ) algorithm. It also allows displaying precalculated trees of the major protein families based on Pfam classification. In PoInTree, nodes can be dynamically opened and closed and distances between genes are graphically represented.Tree root can be centered on a selected leaf. Text search mechanism, color-coding and labeling display are integrated. The visualizer can be connected to an Oracle database containing information on sequences and other biological data, helping to guide their interpretation within a given protein family across multiple species.The application is written in Borland Delphi and based on VCL Teechart Pro 6 graphical component (Steema software).

  1. Fringe trees, Crump-Mode-Jagers branching processes and $m$-ary search trees

    OpenAIRE

    Holmgren, Cecilia; Janson, Svante

    2016-01-01

    This survey studies asymptotics of random fringe trees and extended fringe trees in random trees that can be constructed as family trees of a Crump-Mode-Jagers branching process, stopped at a suitable time. This includes random recursive trees, preferential attachment trees, fragmentation trees, binary search trees and (more generally) $m$-ary search trees, as well as some other classes of random trees. We begin with general results, mainly due to Aldous (1991) and Jagers and Nerman (1984). T...

  2. Doubly robust survival trees.

    Science.gov (United States)

    Steingrimsson, Jon Arni; Diao, Liqun; Molinaro, Annette M; Strawderman, Robert L

    2016-09-10

    Estimating a patient's mortality risk is important in making treatment decisions. Survival trees are a useful tool and employ recursive partitioning to separate patients into different risk groups. Existing 'loss based' recursive partitioning procedures that would be used in the absence of censoring have previously been extended to the setting of right censored outcomes using inverse probability censoring weighted estimators of loss functions. In this paper, we propose new 'doubly robust' extensions of these loss estimators motivated by semiparametric efficiency theory for missing data that better utilize available data. Simulations and a data analysis demonstrate strong performance of the doubly robust survival trees compared with previously used methods. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27037609

  3. Tree farming. Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

    Falk, B. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research)

    1992-07-01

    Fallowed land can initially provide very favourable conditions for tree farming, thus enabling rapid canopy closure and a short rotation period. There may be justification for fertilization, particularly close to the time of canopy closure. Heavy clay soils should be avoided on account of poor tree growth. Crosses of balsam poplar are easy to regenerate through cuttings. The plantation should either be done with small plants protected against damage by game, or with planting stems branched at the bottoms in spacing patterns that are not too dense (3.5x3.5 - 5x5m). Branches at the bottom help to avoid rubbing by deer. Drainage systems are clogged by tree roots and fields drained by subsurface drainage systems should be avoided. Open ditches are sufficient for the requirements of the trees. Selected clones of balsam poplar crosses may have great resistance against disease. However, they do not have a growth rhythm that is ideally suited to Swedish conditions. Further breeding is probably necessary. The main use for balsam poplar is expected to be in the manufacture of pulp, mechanical or chemical. Other uses are veneer, building, glulam and fuel. Under good conditions, height and diameter development suggests a very high production. In plantations with suitable spacing patterns, the economically optimum rotation time is 15-20 year and the plantation appears to withstand high demands for return on investments and price competition. Future activities should foremost be concentrated on development of additional clone material, investigations of wood quality and the establishment and following up of further production experiments. (48 refs., 6 figs., 7 tabs.).

  4. Tree farming; Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

    Falk, B. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    1992-07-01

    Fallowed land can initially provide very favourable conditions for tree farming, thus enabling rapid canopy closure and a short rotation period. There may be justification for fertilization, particularly close to the time of canopy closure. Heavy clay soils should be avoided on account of poor tree growth. Crosses of balsam poplar are easy to regenerate through cuttings. The plantation should either be done with small plants protected against damage by game, or with planting stems branched at the bottoms in spacing patterns that are not too dense (3.5x3.5 - 5x5m). Branches at the bottom help to avoid rubbing by deer. Drainage systems are clogged by tree roots and fields drained by subsurface drainage systems should be avoided. Open ditches are sufficient for the requirements of the trees. Selected clones of balsam poplar crosses may have great resistance against disease. However, they do not have a growth rhythm that is ideally suited to Swedish conditions. Further breeding is probably necessary. The main use for balsam poplar is expected to be in the manufacture of pulp, mechanical or chemical. Other uses are veneer, building, glulam and fuel. Under good conditions, height and diameter development suggests a very high production. In plantations with suitable spacing patterns, the economically optimum rotation time is 15-20 year and the plantation appears to withstand high demands for return on investments and price competition. Future activities should foremost be concentrated on development of additional clone material, investigations of wood quality and the establishment and following up of further production experiments. (48 refs., 6 figs., 7 tabs.).

  5. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  6. Tree Interpolation in Vampire

    OpenAIRE

    McMillan, Ken; Middeldorp, Aart; Voronkov, Andrei; Blanc, Régis; Gupta, Ashutosh; Kovács, Laura; Kragl, Bernhard

    2013-01-01

    We describe new extensions of the Vampire theorem prover for computing tree interpolants. These extensions generalize Craig interpolation in Vampire, and can also be used to derive sequence interpolants. We evaluated our implementation on a large number of examples over the theory of linear integer arithmetic and integer-indexed arrays, with and without quantifiers. When compared to other methods, our experiments show that some examples could only be solved by our implementation.

  7. 76 FR 28948 - Notice of Request for Extension of Approval of an Information Collection; Importation of Gypsy...

    Science.gov (United States)

    2011-05-19

    ...) imported from Canada. These regulated articles are: Trees without roots (e.g., Christmas trees), trees with... shippers of Christmas trees, shrubs, logs, pulpwood, and other articles from gypsy moth-infested...

  8. Pushdown machines for the macro tree transducer

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1986-01-01

    The macro tree transducer can be considered as a system of recursive function procedures with parameters, where the recursion is on a tree (e.g., the syntax tree of a program). We investigate characterizations of the class of tree (tree-to-string) translations which is induced by macro tree transduc

  9. Gene tree correction for reconciliation and species tree inference

    Directory of Open Access Journals (Sweden)

    Swenson Krister M

    2012-11-01

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

  10. Rate of tree carbon accumulation increases continuously with tree size

    Science.gov (United States)

    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

    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.

  11. Save a Tree

    Science.gov (United States)

    Williams, Kathryn R.

    1999-10-01

    Starting in September 1925, JCE reproduced pictures of famous chemists or chemistry-related works of art as frontispieces. Often, the Journal included a biography or other article about the picture. The August 1945 frontispiece featured the largest cork oak in the United States. An accompanying article described the goals of the Cork Project to plant cork trees in suitable locations in the U.S., to compensate for uncertain European and African sources during World War II. The final frontispiece appeared in December 1956. To view supplementary material, please refer to JCE Online's supplementary links.

  12. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

    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.

  13. Limit theorems for sequences of random trees

    OpenAIRE

    Balding, David; Ferrari, Pablo A.; Fraiman, Ricardo; Sued, Mariela

    2004-01-01

    We consider a random tree and introduce a metric in the space of trees to define the ``mean tree'' as the tree minimizing the average distance to the random tree. When the resulting metric space is compact we have laws of large numbers and central limit theorems for sequence of independent identically distributed random trees. As application we propose tests to check if two samples of random trees have the same law.

  14. The Steiner tree problem

    CERN Document Server

    Hwang, FK; Winter, P

    1992-01-01

    The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

  15. Distributed Merge Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther

    2013-01-08

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

  16. The Hill and the Trees

    Institute of Scientific and Technical Information of China (English)

    王燕文

    2007-01-01

    Once there was a well-known hill here. There were many lush trees, beautiful flowers and green grasses on it. One day, the hill said to the trees proudly, “Look, how beautiful I am! But you look so ugly on my back. It must be better if I could drive you away.” One of the trees said, “You won't have beautiful and green clothing without us trees? If you leave us, you will die away.” The hill laughed and said again,”I feel very ashamed for I am staying with you together. Sooner or later I will drive you all...

  17. Human decision error (HUMDEE) trees

    Energy Technology Data Exchange (ETDEWEB)

    Ostrom, L.T.

    1993-08-01

    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.

  18. Tree felling: a necessary evil

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    CERN started a campaign of tree felling in 2010 for safety reasons, and it will continue this year in various parts of the Meyrin site. As in previous years, the trees cut down in 2013 will be recycled and some will be replaced.   Diseased tree that had to be cut down on the Meyrin site. In association with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP), CERN commissioned the Geneva school of landscaping, engineering and architecture (Haute école du paysage, d’ingénierie et d’architecture, HEPIA) to compile an inventory of the trees on the Meyrin site. In total, 1285 trees (excluding poplars) were recorded. 75.5% of these trees were declared to be in a good state of health (i.e. 971 trees), 21.5% in a moderate state of health (276 trees) and 3% in a poor state of health (38 trees). As for the poplars, the 236 specimens recorded on the Meyrin site were judged to be too old, to...

  19. The genetic diversity,relationships,and potential for biological control of the lobate lac scale,Paratachardina pseudolobata Kondo&Gullan(Hemiptera:Coccoidea:Kerriidae),a pest in Florida,the Bahamas,Cuba and Christmas Island

    Science.gov (United States)

    The lobate lac scale Paratachardina pseudolobata Kondo & Gullan (Kerriidae) is a polyphagous pest of woody plants in Florida (U.S.A), the Bahamas, Cuba, and Christmas Island (Australia). Its recent appearance as a pest in these places indicates that this scale is introduced; however, its native rang...

  20. DIF Trees: Using Classification Trees to Detect Differential Item Functioning

    Science.gov (United States)

    Vaughn, Brandon K.; Wang, Qiu

    2010-01-01

    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…

  1. Sussing Merger Trees: A proposed Merger Tree data format

    CERN Document Server

    Thomas, Peter A; Tweed, Dylan; Benson, Andrew J; Croton, Darren; Elahi, Pascal; Henriques, Bruno; Iliev, Ilian T; Knebe, Alexander; Lux, Hanni; Mao, Yao-Yuan; Neyrinck, Mark; Pearce, Frazer R; Rodriguez-Gomez, Vicente; Schneider, Aurel; Srisawat, Chaichalit

    2015-01-01

    We propose a common terminology for use in describing both temporal merger trees and spatial structure trees for dark-matter halos. We specify a unified data format in HDF5 and provide example I/O routines in C, FORTRAN and PYTHON.

  2. Tree Decomposition based Steiner Tree Computation over Large Graphs

    OpenAIRE

    Wei-Kleiner, Fang

    2013-01-01

    In this paper, we present an exact algorithm for the Steiner tree problem. The algorithm is based on certain pre-computed index structures. Our algorithm offers a practical solution for the Steiner tree problems on graphs of large size and bounded number of terminals.

  3. On aligning trees

    CERN Document Server

    Calder, J

    1997-01-01

    The increasing availability of corpora annotated for linguistic structure prompts the question: if we have the same texts, annotated for phrase structure under two different schemes, to what extent do the annotations agree on structuring within the text? We suggest the term tree alignment to indicate the situation where two markup schemes choose to bracket off the same text elements. We propose a general method for determining agreement between two analyses. We then describe an efficient implementation, which is also modular in that the core of the implementation can be reused regardless of the format of markup used in the corpora. The output of the implementation on the Susanne and Penn treebank corpora is discussed.

  4. Tree Quantum Field Theory

    CERN Document Server

    Gurau, R; Rivasseau, V

    2008-01-01

    We propose a new formalism for quantum field theory which is neither based on functional integrals, nor on Feynman graphs, but on marked trees. This formalism is constructive, i.e. it computes correlation functions through convergent rather than divergent expansions. It applies both to Fermionic and Bosonic theories. It is compatible with the renormalization group, and it allows to define non-perturbatively {\\it differential} renormalization group equations. It accommodates any general stable polynomial Lagrangian. It can equally well treat noncommutative models or matrix models such as the Grosse-Wulkenhaar model. Perhaps most importantly it removes the space-time background from its central place in QFT, paving the way for a nonperturbative definition of field theory in noninteger dimension.

  5. Fires on trees

    CERN Document Server

    Bertoin, Jean

    2010-01-01

    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 $\\alpha<1/2$, and to some non-degenerate random variable when $\\alpha=1/2$. We further study the connectivity of the fireproof forest, in particular the existence of a giant component.

  6. Random Projection Trees Revisited

    CERN Document Server

    Dhesi, Aman

    2010-01-01

    The Random Projection Tree structures proposed in [Freund-Dasgupta STOC08] are space partitioning data structures that automatically adapt to various notions of intrinsic dimensionality of data. We prove new results for both the RPTreeMax and the RPTreeMean data structures. Our result for RPTreeMax gives a near-optimal bound on the number of levels required by this data structure to reduce the size of its cells by a factor $s \\geq 2$. We also prove a packing lemma for this data structure. Our final result shows that low-dimensional manifolds have bounded Local Covariance Dimension. As a consequence we show that RPTreeMean adapts to manifold dimension as well.

  7. ATLAS Christmas lunch

    CERN Document Server

    Francois Butin; Markus Nordberg

    The end of the year ATLAS pit lunch is now a well established tradition: the 4th edition took place in the most prestigious place at CERN; the "Globe de l'innovation", or simply "the Globe". This end-of-year event is the opportunity to thank all those working so hard at Point 1. The first event took place in December 2003. At that time, there was no Globe yet, and the party took place in SX1 building, at the top of the shafts leading to the ATLAS cavern, with some 100 guests. In December 2004, we had the privilege to be the first to organize a lunch in the Globe with some 200 guests. Since then, many have followed our example! Well, almost: we were requested to refrain from serving "Tartiflette" again in there (a Savoyard specialty, using vast amounts of Reblochon, a smelly cheese...). It was said to have left a poignant odour for following events throughout 2004... Long queues formed for this special event. In December 2005, we were authorized to party in the Globe again (once we promised we would b...

  8. Thanksgiving Day and Christmas

    Institute of Scientific and Technical Information of China (English)

    朱妤

    2009-01-01

    @@ Turkey(火鸡)is the traditional(传统的) meat at the feast(筵席),and such autumnal dishes as pumpkin(南瓜) pie and plum pudding (葡萄干布丁) stress the harvest theme(主题). Deoember 25 is a Christian festival and is observed as the anniversary(周年纪念) of the birth of Christ,although there is nothing in the New Testament (圣经的新约全书) to indicate (表明) that this is the date of Nativity (耶稣诞生日).

  9. The Christmas list

    CERN Multimedia

    James Gillies

    2010-01-01

    List making seems to be among mankind’s favourite activities, particularly as the old year draws to a close and the new one begins. It seems that we all want to know what the top 100 annoying pop songs are, who are the world’s most embarrassing people and what everyone’s been watching on TV. The transition from 2009 to 2010 was no different, but some of the latest batch of lists have a few surprising entries. According to the Global Language Monitor, ‘twitter’ was the top word of 2009. No surprises there, but ‘hadron’ came in at number 8 on the list. ‘King of pop’ was top phrase, according to the same source, but ‘god particle’ came in at number 10. And while ‘Barack Obama’ was the name of the year, ‘Large Hadron Collider’ came in at number four. The Global Language Monitor was not the only organization whose lists included particle physics references. &ls...

  10. Case Study - "Marketing Christmas"

    Institute of Scientific and Technical Information of China (English)

    何青青

    2011-01-01

    @@ The following is based on a real case but the name of the company has been changed and the source will only be revealed after the submission deadline.It is June in Eastern China and temperatures are over 30 degrees Celsius.In Huang Yi-Ju's wholesale showroom, based in Yiwu, model Father Christmases line the shelves, fill the floors and scale the walls.

  11. The Christmas star

    Institute of Scientific and Technical Information of China (English)

    孙飞

    2004-01-01

    Thiswasmygrandmother’sfirstChristmaswithoutGrandfather熏andwehadpromisedhimbeforehepassedaway(逝世)thatwewouldmakethisherbestChristmasever.Whenmymom熏dad熏threesistersandIarrivedatherlit鄄tlehouseintheBlueRidgeMountainsinNorthCarolina熏wefoundshehadwaitedupallnightforustoarrivefromTexas.Afterweexchanged(互换)hugs(拥抱)熏Donna熏Karen熏KristiandIranintothehouse.ItdidseemalittleemptywithoutGrandfather熏andweknewitwasuptoustomakethisChristmasspecialforher.GrandfatherhadalwayssaidthattheChrist鄄mastreewasthemostimportantdecorat...

  12. Johannes Kepler on Christmas

    Science.gov (United States)

    Kemp, Martin

    2009-12-01

    Kepler's interpretation of the supernova of 1604, De Stella Nova, interwove the science of astronomy with astrology and theology in an attempt to determine the correct birthdate of Jesus, explains Martin Kemp.

  13. TREE DECOMPOSITIONS OF MULTIGRAPHS

    Institute of Scientific and Technical Information of China (English)

    SHI Minyong

    1999-01-01

    For a graph G, ifE(G) can be partitioned into several pairwise disjointsets as { E1, E2,……,El} such thatthe subgraph induced by Ei is a tree of orderki, (i=1,2, ……, l), then G is said to have a {k1,k2,……, kl}-tree-decomposition, denoted by {k1,k2,……, kl}∈G.For k≥1 and l≥0, a collection(G)(k,l) is the setof multigraphs such that G∈(G)(k,l) if and only if ε(G) = k(|G|-1)-l and ε(H)≤max{(k-1)(|H|-1), k(|H|-1)-l} for any subgraph H of G.We prove that (1) If k≥2, 0≤l≤3 and G∈(G)(k,l) of order n≥l+1, then {n,n,……, n-l}∈ G. (2) If k≥2 and G∈(G)(k,2) oforder n≥3, then {n,n,……, n,n-2}∈G and {n,n,……, n,n-1,n-1}∈G. (3) If k3 and G∈(G)(k,3) oforder n≥4, then {n,n,……, n,n-3}∈G ,{ n,n,……, n,n-1,n-2}∈ G and {n,n, ……, n,n-1,n-1,n-1}∈G.

  14. Misunderstanding sap ascent in trees

    OpenAIRE

    Cochard, Hervé; Delzon, Sylvain

    2013-01-01

    Trees transport water from their roots to their leaves thanks to an efficient but vulnerable vascular system. Assessing the vulnerability to drought of the xylem and its ability to recover from failure are not an easy task but recent findings demonstrate that, contrary to what is commonly believed, hydraulic failure and embolism repair are not routine in trees.

  15. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    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…

  16. Some Hopf algebras of trees

    NARCIS (Netherlands)

    Laan, P. van der

    2001-01-01

    In the literature several Hopf algebras that can be described in terms of trees have been studied. This paper tries to answer the question whether one can understand some of these Hopf algebras in terms of a single mathematical construction. The starting point is the Hopf algebra of rooted trees as

  17. Community tree nursery, Meru, Kenya.

    OpenAIRE

    2006-01-01

    This is a photograph of a community tree nursery, Meru, Kenya. In this nursery a community group has started a nursery to provide seedlings for their own forest reforestation projects as well as for sale. This shows that use of common pool resources and shows community forestry activities that also do private tree planting on homesteads.

  18. Modelling tree biomasses in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Repola, J.

    2013-06-01

    Biomass equations for above- and below-ground tree components of Scots pine (Pinus sylvestris L), Norway spruce (Picea abies [L.] Karst) and birch (Betula pendula Roth and Betula pubescens Ehrh.) were compiled using empirical material from a total of 102 stands. These stands (44 Scots pine, 34 Norway spruce and 24 birch stands) were located mainly on mineral soil sites representing a large part of Finland. The biomass models were based on data measured from 1648 sample trees, comprising 908 pine, 613 spruce and 127 birch trees. Biomass equations were derived for the total above-ground biomass and for the individual tree components: stem wood, stem bark, living and dead branches, needles, stump, and roots, as dependent variables. Three multivariate models with different numbers of independent variables for above-ground biomass and one for below-ground biomass were constructed. Variables that are normally measured in forest inventories were used as independent variables. The simplest model formulations, multivariate models (1) were mainly based on tree diameter and height as independent variables. In more elaborated multivariate models, (2) and (3), additional commonly measured tree variables such as age, crown length, bark thickness and radial growth rate were added. Tree biomass modelling includes consecutive phases, which cause unreliability in the prediction of biomass. First, biomasses of sample trees should be determined reliably to decrease the statistical errors caused by sub-sampling. In this study, methods to improve the accuracy of stem biomass estimates of the sample trees were developed. In addition, the reliability of the method applied to estimate sample-tree crown biomass was tested, and no systematic error was detected. Second, the whole information content of data should be utilized in order to achieve reliable parameter estimates and applicable and flexible model structure. In the modelling approach, the basic assumption was that the biomasses of

  19. Changing children's understanding of the brain: a longitudinal study of the Royal Institution Christmas Lectures as a measure of public engagement.

    Directory of Open Access Journals (Sweden)

    Nathalia L Gjersoe

    Full Text Available Demonstrating the impact of public engagement is an increasingly important activity for today's academics and researchers. The difficulty is that many areas of interest do not lend themselves well to evaluation because the impact of each single intervention can be hard to trace and take time to become manifest. With this in mind, we evaluated a lecture based around the 2011 Royal Institution Christmas Lectures, "Meet Your Brain," delivered to school children from low performing schools. We compared knowledge about four neuroscience facts one week before, one week after and six weeks after the lecture. Analysis revealed significant knowledge transfer one week after the lecture that was retained five weeks later. We conclude that public engagement through tailored lectures can have significant impact in the moderate term with the potential to leave a lasting impression over a longer period.

  20. Spanning Trees in Random Satisfiability Problems

    OpenAIRE

    Ramezanpour, A.; Moghimi-Araghi, S.

    2005-01-01

    Working with tree graphs is always easier than with loopy ones and spanning trees are the closest tree-like structures to a given graph. We find a correspondence between the solutions of random K-satisfiability problem and those of spanning trees in the associated factor graph. We introduce a modified survey propagation algorithm which returns null edges of the factor graph and helps us to find satisfiable spanning trees. This allows us to study organization of satisfiable spanning trees in t...

  1. 76 FR 69700 - Klamath National Forest; California; Pumice Vegetation Management Project

    Science.gov (United States)

    2011-11-09

    ...; (7) Commercial Christmas Trees; and (8) Prescribed Fire. In addition to the above treatments, the... Christmas Trees (94 acres): Shasta red and white fir trees less than eight inches DBH will be...

  2. Are There Infinite Irrigation Trees?

    Science.gov (United States)

    Bernot, M.; Caselles, V.; Morel, J. M.

    2006-08-01

    In many natural or artificial flow systems, a fluid flow network succeeds in irrigating every point of a volume from a source. Examples are the blood vessels, the bronchial tree and many irrigation and draining systems. Such systems have raised recently a lot of interest and some attempts have been made to formalize their description, as a finite tree of tubes, and their scaling laws [25], [26]. In contrast, several mathematical models [5], [22], [10], propose an idealization of these irrigation trees, where a countable set of tubes irrigates any point of a volume with positive Lebesgue measure. There is no geometric obstruction to this infinitesimal model and general existence and structure theorems have been proved. As we show, there may instead be an energetic obstruction. Under Poiseuille law R(s) = s -2 for the resistance of tubes with section s, the dissipated power of a volume irrigating tree cannot be finite. In other terms, infinite irrigation trees seem to be impossible from the fluid mechanics viewpoint. This also implies that the usual principle analysis performed for the biological models needs not to impose a minimal size for the tubes of an irrigating tree; the existence of the minimal size can be proven from the only two obvious conditions for such irrigation trees, namely the Kirchhoff and Poiseuille laws.

  3. What Good Is a Tree?

    Institute of Scientific and Technical Information of China (English)

    Lowell; Ponte; 史书碧

    1998-01-01

    文章开头说:Trees are so common and quiet that we pay them little mind. 其实,初见此标题——What Good Is a Tree?笔者也pay this essay little mind。这个题目还能够讲出多少新意来呢?不料,细读之后,竟不忍释手! Trees sustain our lives and our planet in a thousand practical ways. Trees do more than make life pleasant;they make life possible. 这是文章的两句主题句。读罢全文,认真一想,便觉这决非耸人听闻之言:无言的树,“挪死”的树,支撑着我们这个星球,庇护着天下的生灵!诸如: …they draw carbon dioxide from the air…and oxygen iS released. Without tree our entire world would be a much drier place. For centuries,the Chinese have derived medicines form the ginkgo tree. 让读者双眼一亮的是,文章提供了许多你我都不曾想到的有关树的信息: a.树木能彼此互通信息: …trees send unseen signals to each other.When willows are attacked bywebworms and tent caterpillars,they give off a chemical that alerts nearby trees.Theneighboring trees respond by pumping more tannin into their leaves,making them moredifficult for the insects tO digest。 更让人?

  4. Tree for all reasons

    Energy Technology Data Exchange (ETDEWEB)

    Sang, T.

    1980-04-01

    For centuries Chinese peasants have planted paulownia trees, not only for their beauty but also for their fast-growing characteristics - an amazing average of 0.37 cubic meters of timber per year. The leaves, flowers, fruits and bark can be used as medicines and, because of their high nitrogen content the leaves are used as fodder. But above all, paulownias are increasingly being used by Chinese peasants to boost grain output. In Lanka county, Henan province, for example, grain output has increased to an average of 5.25 tons per hectare from less than 0.75 tons in 1963 when paulownia interplanting as a system was introduced. They help crops to withstand sandstorms, droughts and frosts, they increase air humidity and reduce evaporation of moisture in the fields. They do not compete with crops for fertilizer and water since about 80% of their absorbing roots reach a depth of 40-100 cm, while most cereals roots are less than 40 cm.

  5. Counting spanning trees in graphs

    OpenAIRE

    Azarija, Jernej

    2012-01-01

    The history of counting the number of spanning trees dates back into the year 1842 in which the German mathematician Gustav Kirchhoff derived a relation between the number of spanning trees of a graph G (τ(G)) and the determinant of a specific submatrix associated with G. After this result many other related results followed. For example in 1889 the British mathematician A. Cayley showed that the complete graph on n nodes has nn−2 spanning trees.The function τ can nowadays be found in the fi...

  6. Trees Are Useful to Man

    Institute of Scientific and Technical Information of China (English)

    赵明

    2005-01-01

    Trees are useful to man in three impor-tant ways. They provide him with wood and other products;they give him shade;they help prevent drought(干旱)and floods. Unfortunately,in many parts of the world, man has not realized that the third one is the most important. Two thousand years ago a rich and pow-erful country cut down its trees to build war-ships, with which to gain itself an empire. It gained the empire,however,without its trees, its soil became hard and poor. When the em-pire fell to pieces, the home c...

  7. Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative

    OpenAIRE

    Pincetl, Stephanie

    2010-01-01

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

  8. A suffix tree or not a suffix tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    In this paper we study the structure of suffix trees. Given an unlabeled tree τ on n nodes and suffix links of its internal nodes, we ask the question “Is τ a suffix tree?”, i.e., is there a string S whose suffix tree has the same topological structure as τ? We place no restrictions on S...... if τ is a suffix tree is not an easy task, because, with no restrictions on the final symbol, we cannot guess the length of a string that realizes τ from the number of leaves. And without an upper bound on the length of such a string, it is not even clear how to solve the problem by an exhaustive...... search. In this paper, we prove that τ is a suffix tree if and only if it is realized by a string S of length n-1, and we give a linear-time algorithm for inferring S when the first letter on each edge is known. This generalizes the work of I et al. (2014) [15]. [All rights reserved Elsevier]....

  9. Implementing Municipal Tree Planting: Los Angeles Million-Tree Initiative

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

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

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

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

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

  11. Trees : relief for the city

    NARCIS (Netherlands)

    Hiemstra, J.A.; Schoenmaker-van der Bijl, E.; Tonneijck, A.E.G.; Hoffman, M.H.A.

    2008-01-01

    Mogelijkheden ter bestrijding van fijnstofThis brochure describes the underlying principles that form a basis for better-informed choices with regards to the management of trees and shrubs in cities and the design of functional planting schemes.

  12. Visualizing Contour Trees within Histograms

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Many of the topological features of the isosurfaces of a scalar volume field can be compactly represented by its contour tree. Unfortunately, the contour trees of most real-world volume data sets are too complex to be visualized by dot-and-line diagrams. Therefore, we propose a new visualization...... that is suitable for large contour trees and efficiently conveys the topological structure of the most important isosurface components. This visualization is integrated into a histogram of the volume data; thus, it offers strictly more information than a traditional histogram. We present algorithms...... to automatically compute the graph layout and to calculate appropriate approximations of the contour tree and the surface area of the relevant isosurface components. The benefits of this new visualization are demonstrated with the help of several publicly available volume data sets....

  13. Algorithms for Decision Tree Construction

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    The study of algorithms for decision tree construction was initiated in 1960s. The first algorithms are based on the separation heuristic [13, 31] that at each step tries dividing the set of objects as evenly as possible. Later Garey and Graham [28] showed that such algorithm may construct decision trees whose average depth is arbitrarily far from the minimum. Hyafil and Rivest in [35] proved NP-hardness of DT problem that is constructing a tree with the minimum average depth for a diagnostic problem over 2-valued information system and uniform probability distribution. Cox et al. in [22] showed that for a two-class problem over information system, even finding the root node attribute for an optimal tree is an NP-hard problem. © Springer-Verlag Berlin Heidelberg 2011.

  14. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

  15. Efficient Frequent Pattern Tree Construction

    Directory of Open Access Journals (Sweden)

    D.Bujji Babu

    2014-03-01

    Full Text Available Association rule learning is a popular and well researched technique for discovering interesting relations between variables in large databases in the area of data mining. The association rules are a part of intelligent systems. Association rules are usually required to satisfy a user-specified minimum support and a user-specified minimum confidence at the same time. Apriori and FP-Growth algorithms are very familiar algorithms for association rule mining. In this paper we are more concentrated on the Construction of efficient frequent pattern trees. Here, we present the novel frequent pattern trees and the performance issues. The proposed trees are fast and efficient trees helps to extract the frequent patterns. This paper provides the major advantages in the FP-Growth algorithm for association rule mining with using the newly proposed approach.

  16. Tree and tree-like species of Mexico: gymnosperms, monocotyledons, and tree ferns

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.

    2010-01-01

    Trees or tree-like plants are defined here broadly as perennial, self-supporting plants with an adult height of at least 5 m (without ascending leaves or inflorescences), and with 1 or several erect stems with a diameter of at least 10 cm. We present an updated list of all Mexican tree species under that definition in the Gymnospermae (86 species, 38% endemic to Mexico), Monocotyledonae (75 species, 55% endemic), and Pteridophyta (9 species, none endemic). The list contains a total of 170 spe...

  17. Short Tree, Long Tree, Right Tree, Wrong Tree: New Acquisition Bias Corrections for Inferring SNP Phylogenies.

    Science.gov (United States)

    Leaché, Adam D; Banbury, Barbara L; Felsenstein, Joseph; de Oca, Adrián Nieto-Montes; Stamatakis, Alexandros

    2015-11-01

    Single nucleotide polymorphisms (SNPs) are useful markers for phylogenetic studies owing in part to their ubiquity throughout the genome and ease of collection. Restriction site associated DNA sequencing (RADseq) methods are becoming increasingly popular for SNP data collection, but an assessment of the best practises for using these data in phylogenetics is lacking. We use computer simulations, and new double digest RADseq (ddRADseq) data for the lizard family Phrynosomatidae, to investigate the accuracy of RAD loci for phylogenetic inference. We compare the two primary ways RAD loci are used during phylogenetic analysis, including the analysis of full sequences (i.e., SNPs together with invariant sites), or the analysis of SNPs on their own after excluding invariant sites. We find that using full sequences rather than just SNPs is preferable from the perspectives of branch length and topological accuracy, but not of computational time. We introduce two new acquisition bias corrections for dealing with alignments composed exclusively of SNPs, a conditional likelihood method and a reconstituted DNA approach. The conditional likelihood method conditions on the presence of variable characters only (the number of invariant sites that are unsampled but known to exist is not considered), while the reconstituted DNA approach requires the user to specify the exact number of unsampled invariant sites prior to the analysis. Under simulation, branch length biases increase with the amount of missing data for both acquisition bias correction methods, but branch length accuracy is much improved in the reconstituted DNA approach compared to the conditional likelihood approach. Phylogenetic analyses of the empirical data using concatenation or a coalescent-based species tree approach provide strong support for many of the accepted relationships among phrynosomatid lizards, suggesting that RAD loci contain useful phylogenetic signal across a range of divergence times despite the

  18. Quantum Simulation of Phylogenetic Trees

    OpenAIRE

    Ellinas, Demosthenes; Jarvis, Peter

    2011-01-01

    Quantum simulations constructing probability tensors of biological multi-taxa in phylogenetic trees are proposed, in terms of positive trace preserving maps, describing evolving systems of quantum walks with multiple walkers. Basic phylogenetic models applying on trees of various topologies are simulated following appropriate decoherent quantum circuits. Quantum simulations of statistical inference for aligned sequences of biological characters are provided in terms of a quantum pruning map o...

  19. Generic physical protection logic trees

    International Nuclear Information System (INIS)

    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

  20. Generic physical protection logic trees

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, W.K.

    1981-10-01

    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.

  1. Microwave sensing of tree trunks

    Science.gov (United States)

    Jezova, Jana; Mertens, Laurence; Lambot, Sebastien

    2015-04-01

    The main subject of this research is the observation of the inner part of living tree trunks using ground-penetrating radar (GPR). Trees are everyday part of human life and therefore it is important to pay attention to the tree conditions. The most obvious consequence of the poor tree condition is dead or injury caused by falling tree. The trunk internal structure is divided into three main parts: heartwood, sapwood and bark, which make this medium highly anisotropic and heterogeneous. Furthermore, the properties of the wood are not only specie-dependent but also depend on genetic and on environmental conditions. In urban areas the main problem for the stability of the trees relies in the apparition of decays provoked by fungi, insect or birds. This results in cavities or decreasing of the support capacity of the tree. GPR has proved itself to be a very powerful electromagnetic tool for non-destructive detection of buried objects. Since the beginning of the 20th century it has been used in several different areas (archaeology, landmine detection, civil engineering, ...). GPR uses the principle of the scattering of the electromagnetic waves that are radiated from a transmitting antenna. Then the waves propagate through the medium and are reflected from the object and then they are received by a receiving antenna. The velocity of the scattered signal is determined primarily by the permittivity of the material. The optimal functionality of the GPR was investigated using the numerical simulation tool gprMax2D. This tool is based on a Finite-Difference Time-Domain (FDTD) numerical model. Subsequently, the GPR functionality was tested using the laboratory model of a decayed tree trunk. Afterwards, the results and lessons learnt in the simplified tests will be used in the processing of the real data and will help to achieve deeper understanding of them. The laboratory model of the tree trunk was made by plastic or carton pipes and filled by sand. Space inside the model

  2. Balanced binary trees in the Tamari lattice

    CERN Document Server

    Giraudo, Samuele

    2010-01-01

    We show that the set of balanced binary trees is closed by interval in the Tamari lattice. We establish that the intervals [T0, T1] where T0 and T1 are balanced trees are isomorphic as posets to a hypercube. We introduce tree patterns and synchronous grammars to get a functional equation of the generating series enumerating balanced tree intervals.

  3. Hi-trees and their layout.

    Science.gov (United States)

    Marriott, Kim; Sbarski, Peter; van Gelder, Tim; Prager, Daniel; Bulka, Andy

    2011-03-01

    We introduce hi-trees, a new visual representation for hierarchical data in which, depending on the kind of parent node, the child relationship is represented using either containment or links. We give a drawing convention for hi-trees based on the standard layered drawing convention for rooted trees, then show how to extend standard bottom-up tree layout algorithms to draw hi-trees in this convention. We also explore a number of other more compact layout styles for layout of larger hi-trees and give algorithms for computing these. Finally, we describe two applications of hi-trees: argument mapping and business decision support.

  4. Sussing Merger Trees: The Merger Trees Comparison Project

    Science.gov (United States)

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

    2013-11-01

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

  5. A bicriterion Steiner tree problem on graph

    Directory of Open Access Journals (Sweden)

    Vujošević Mirko B.

    2003-01-01

    Full Text Available This paper presents a formulation of bicriterion Steiner tree problem which is stated as a task of finding a Steiner tree with maximal capacity and minimal length. It is considered as a lexicographic multicriteria problem. This means that the bottleneck Steiner tree problem is solved first. After that, the next optimization problem is stated as a classical minimums Steiner tree problem under the constraint on capacity of the tree. The paper also presents some computational experiments with the multicriteria problem.

  6. Isoprene emission from Indian trees

    Science.gov (United States)

    Varshney, C. K.; Singh, Abhai Pratap

    2003-12-01

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

  7. View Dependent Sequential Point Trees

    Institute of Scientific and Technical Information of China (English)

    Wen-Cheng Wang; Feng Wei; En-Hua Wu

    2006-01-01

    Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.

  8. Tree Coding of Bilevel Images

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1998-01-01

    be investigated within reasonable time prior to generating the code. A number of general-purpose coders are constructed according to this principle. Rissanen's (1989) one-pass algorithm, context, is presented in two modified versions. The baseline is proven to be a universal coder. The faster version, which...... probabilities to an arithmetic coder. The conditional probabilities are estimated from co-occurrence statistics of past pixels, the statistics are stored in a tree. By organizing the code length calculations properly, a vast number of possible models (trees) reflecting different pixel orderings can...... is one order of magnitude slower than JBIG, obtains excellent and highly robust compression performance. A multipass free tree coding scheme produces superior compression results for all test images. A multipass free template coding scheme produces significantly better results than JBIG for difficult...

  9. Negative Tree Reweighted Belief Propagation

    CERN Document Server

    Liu, Qiang

    2012-01-01

    We introduce a new class of lower bounds on the log partition function of a Markov random field which makes use of a reversed Jensen's inequality. In particular, our method approximates the intractable distribution using a linear combination of spanning trees with negative weights. This technique is a lower-bound counterpart to the tree-reweighted belief propagation algorithm, which uses a convex combination of spanning trees with positive weights to provide corresponding upper bounds. We develop algorithms to optimize and tighten the lower bounds over the non-convex set of valid parameter values. Our algorithm generalizes mean field approaches (including naive and structured mean field approximations), which it includes as a limiting case.

  10. Rectilinear Full Steiner Tree Generation

    DEFF Research Database (Denmark)

    Zachariasen, Martin

    1999-01-01

    The fastest exact algorithm (in practice) for the rectilinear Steiner tree problem in the plane uses a two-phase scheme: First, a small but sufficient set of full Steiner trees (FSTs) is generated and then a Steiner minimum tree is constructed from this set by using simple backtrack search, dynamic...... programming, or an integer programming formulation. FST generation methods can be seen as problem-reduction algorithms and are also useful as a first step in providing good upper and lower bounds for large instances. Currently, the time needed to generate FSTs poses a significant overhead for FST-based exact...... algorithms. In this paper, we present a very efficient algorithm for the rectilinear FST generation problem which removes this overhead completely. Based on information obtained in a preprocessing phase, the new algorithm grows FSTs while applying several new and important optimality conditions. For randomly...

  11. On the Count of Trees

    CERN Document Server

    Barcenas, Everardo; Layaida, Nabil; Schmitt, Alan

    2010-01-01

    Regular tree grammars and regular path expressions constitute core constructs widely used in programming languages and type systems. Nevertheless, there has been little research so far on frameworks for reasoning about path expressions where node cardinality constraints occur along a path in a tree. We present a logic capable of expressing deep counting along paths which may include arbitrary recursive forward and backward navigation. The counting extensions can be seen as a generalization of graded modalities that count immediate successor nodes. While the combination of graded modalities, nominals, and inverse modalities yields undecidable logics over graphs, we show that these features can be combined in a decidable tree logic whose main features can be decided in exponential time. Our logic being closed under negation, it may be used to decide typical problems on XPath queries such as satisfiability, type checking with relation to regular types, containment, or equivalence.

  12. Attention trees and semantic paths

    Science.gov (United States)

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

    2007-02-01

    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

  13. Tree hydraulics: how sap rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown—a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by transpiration or capillary action; we investigate the effectiveness of both these forces for the two conduit architectures considered. The level of analysis is appropriate for undergraduates. The subject is of broad interest because it provides a naturally-occurring example of an unusual metastable state of matter: liquid under tension.

  14. Water Transport in Trees--An Artificial Laboratory Tree

    Science.gov (United States)

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

    2011-01-01

    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…

  15. Sussing Merger Trees: The Merger Trees Comparison Project

    CERN Document Server

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

    2013-01-01

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

  16. Tree Height Calculator: An Android App for Estimating Tree Height

    Science.gov (United States)

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

    2011-12-01

    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.

  17. Symposium on nitrogen fixation in tropical trees

    Energy Technology Data Exchange (ETDEWEB)

    Dobereiner, J.

    1984-01-01

    A special issue containing the proceedings of an international symposium held on 19-24 September 1983 at Rio de Janeiro. Some 35 papers were presented in six sessions: Importance of leguminous trees (2 papers); Occurrence of leguminous trees (5); Nitrogen fixation in trees (12); Utilization of nitrogen fixing trees (7); Nutrition of leguminous trees (5); and Agroforestry systems (4). Recommendations of the symposium are presented on p. 341-344 (Pt, En), and a List of nitrogen fixing trees which should receive immediate attention in Brazil (26 species) is given on p. 345.

  18. Human action analysis with randomized trees

    CERN Document Server

    Yu, Gang; Liu, Zicheng

    2014-01-01

    This book will provide a comprehensive overview on human action analysis with randomized trees. It will cover both the supervised random trees and the unsupervised random trees. When there are sufficient amount of labeled data available, supervised random trees provides a fast method for space-time interest point matching. When labeled data is minimal as in the case of example-based action search, unsupervised random trees is used to leverage the unlabelled data. We describe how the randomized trees can be used for action classification, action detection, action search, and action prediction.

  19. Edge-Disjoint Fibonacci Trees in Hypercube

    Directory of Open Access Journals (Sweden)

    Indhumathi Raman

    2014-01-01

    Full Text Available The Fibonacci tree is a rooted binary tree whose number of vertices admit a recursive definition similar to the Fibonacci numbers. In this paper, we prove that a hypercube of dimension h admits two edge-disjoint Fibonacci trees of height h, two edge-disjoint Fibonacci trees of height h-2, two edge-disjoint Fibonacci trees of height h-4 and so on, as subgraphs. The result shows that an algorithm with Fibonacci trees as underlying data structure can be implemented concurrently on a hypercube network with no communication latency.

  20. Forward and Backward Application of Symbolic Tree Transducers

    OpenAIRE

    Fülöp, Zoltán; Vogler, Heiko

    2012-01-01

    We consider symbolic tree automata (sta) and symbolic tree transducers (stt). We characterize s-recognizable tree languages (which are the tree languages recognizable by sta) in terms of (classical) recognizable tree languages and relabelings. We prove that sta and the recently introduced variable tree automata are incomparable with respect to their recognition power. We define symbolic regular tree grammars and characterize s-regular tree languages in terms of regular tree languages and rela...

  1. Los anuncios de juguetes en la campaña de Navidad Content analysis about toy’s advertisment during Christmas campaign

    Directory of Open Access Journals (Sweden)

    Marina Ferrer López

    2007-10-01

    Full Text Available En nuestros días, la publicidad se ha convertido en una herramienta de gran influencia en los gustos y preferencias de los niños. El presente estudio intenta analizar las características de los anuncios de juguetes en un periodo en el que se emiten masivamente como es la campaña de navidad. Los datos obtenidos revelan que la ambigüedad de la ley que regula este tipo de publicidad hace que se siga dando fuertes estereotipos femeninos y masculinos o discursos que permiten crear una imagen del producto mitificada e irreal. Nowadays, advertising is a tool with great influence on children’s tastes and preferences. This study tries to analyze the characteristics of advertisements of toys during the Christmas campaign, when there is a saturation of this type of advertisements. Our results show that the ambiguity of the law that regulates this type of publicity still allows strong male and female stereotypes, and a discourse that creates an unreal image of the product.

  2. The Trees that surround us

    Science.gov (United States)

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

    2012-04-01

    In our school the activities linked with sciences are developed in a partnership with other school subjects. Interdisciplinary projects are always valued from beginning to end of a project. It is common for teachers of different areas to work together in a Science project. Research of English written articles is very important not only for the development of our students' scientific literacy but also as a way of widening knowledge and a view on different perspectives of life instead of being limited to research of any articles in Portuguese language. In this study we are going to collect data about the predominant tree species in the region, especially the invasive trees from the acacia species, the native tree species and the commercial species. We are going to study the reasons for the appearance of each species and draw a chart of soil occupation in the council. This chart will also allow the study of the distribution and use of land for each tree species. This research work is the first stage for a contribution to warn the town council of the dangers of the invasive species to the future economy of the council.

  3. Can Children Read Evolutionary Trees?

    Science.gov (United States)

    Ainsworth, Shaaron; Saffer, Jessica

    2013-01-01

    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…

  4. A distributed spanning tree algorithm

    DEFF Research Database (Denmark)

    Johansen, Karl Erik; Jørgensen, Ulla Lundin; Nielsen, Svend Hauge;

    1988-01-01

    We present a distributed algorithm for constructing a spanning tree for connected undirected graphs. Nodes correspond to processors and edges correspond to two way channels. Each processor has initially a distinct identity and all processors perform the same algorithm. Computation as well...

  5. Trees of Our National Forests.

    Science.gov (United States)

    Forest Service (USDA), Washington, DC.

    Presented is a description of the creation of the National Forests system, how trees grow, managing the National Forests, types of management systems, and managing for multiple use, including wildlife, water, recreation and other uses. Included are: (1) photographs; (2) line drawings of typical leaves, cones, flowers, and seeds; and (3)…

  6. The Tree of Life Project

    Science.gov (United States)

    Milbrath, Sherry

    2009-01-01

    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…

  7. Automated Generation of Attack Trees

    DEFF Research Database (Denmark)

    Vigo, Roberto; Nielson, Flemming; Nielson, Hanne Riis

    2014-01-01

    are automatically inferred from a process algebraic specification in a syntax-directed fashion, encompassing a great many application domains and avoiding incurring systematically an exponential explosion. Moreover, we show how the standard propositional denotation of an attack tree can be used to phrase...

  8. ESTONIAN TRACES IN THE TREE OF LIFE CONCEPT AND IN THE LANGUAGE FAMILY TREE THEORY

    Directory of Open Access Journals (Sweden)

    Urmas Sutrop

    2012-01-01

    Full Text Available In this paper the tree model – a well-formed tree is shortly described. After that the language family tree model by August Schleicher is treated and compared with the Charles Darwin’s tree of life diagram and metaphor. The development of the idea of the linguistic trees and the tree of life is considered historically. Earlier models – scala naturae – and tree models, both well-formed and not-well-formed are introduced. Special attention is paid to the scholars connected to Estonia who developed the idea of tree models: Georg Stiernhielm was the first who pictured a language tree already in 1671; Karl Eduard Eichwald published an early tree of animal life in 1829; and Karl Ernst von Baer influenced the tree of life models and diagrams of Charles Darwin.

  9. Tilting mutation of Brauer tree algebras

    CERN Document Server

    Aihara, T

    2010-01-01

    We define tilting mutations of symmetric algebras as the endomorphism algebras of Okuyama-Rickard complexes. For Brauer tree algebras, we give an explicit description of the change of Brauer trees under mutation.

  10. Computing Refined Buneman Trees in Cubic Time

    DEFF Research Database (Denmark)

    Brodal, G.S.; Fagerberg, R.; Östlin, A.;

    2003-01-01

    proposed edge. The currently best algorithm for computing the refined Buneman tree from a given distance measure has a running time of O(n 5) and a space consumption of O(n 4). In this paper, we present an algorithm with running time O(n 3) and space consumption O(n 2). The improved complexity of our......Reconstructing the evolutionary tree for a set of n species based on pairwise distances between the species is a fundamental problem in bioinformatics. Neighbor joining is a popular distance based tree reconstruction method. It always proposes fully resolved binary trees despite missing evidence...... in the underlying distance data. Distance based methods based on the theory of Buneman trees and refined Buneman trees avoid this problem by only proposing evolutionary trees whose edges satisfy a number of constraints. These trees might not be fully resolved but there is strong combinatorial evidence for each...

  11. International Tree Ring Data Bank (ITRDB)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives. Data include raw treering measurements (most are...

  12. Organic tree propagation under Welsh nursery conditions

    OpenAIRE

    Frost, David; Clarke, Aldwyn

    2007-01-01

    The demand for organically raised tree and hedging plants had been reported from organic farmers in Tir Gofal, as well as within the landscaping industry. Although there are a number of plant raising nurseries producing organically raised plants for vegetable and fruit production, there are no tree nurseries producing to organic standards. Nursery tree growers were concerned that there was currently too little known about the performance of tree seedlings in organic substrates (e.g. in root-t...

  13. Animals and trees: food for thought

    Energy Technology Data Exchange (ETDEWEB)

    Openshaw, K.

    1979-01-01

    In many areas of Africa, combining tree-growing with animal rearing is advantageous, as the trees provide shade, animal fodder and timber for fuel and building, while grazing animals reduce the fire hazard from ground vegetation and improve soil fertility through droppings. Acacia albida, Prosopis cineraria, P. chilensis, leucaena leucocephala and Ailanthus excelsa are discussed as promising fodder trees, and an appendix is included with notes on 21 other trees for fodder or the production of medicines.

  14. The LIGNUM functional-structural tree model

    OpenAIRE

    Perttunen, Jari

    2009-01-01

    The aim of this thesis was to construct a single tree model that builds a bridge between traditional process based tree models and detailed, three-dimensional architectural tree models. The result of the thesis, the functional-structural tree model LIGNUM, integrates both the functional and the structural aspects of woody arborescent plants in a single generic modelling framework. The thesis consists of five articles and the summary part. The first article presents the model structure of...

  15. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Tsichlas, Kostas;

    2010-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D 2-tree). The D 2-tree compares favourably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers...

  16. Design of data structures for mergeable trees

    DEFF Research Database (Denmark)

    Georgiadis, Loukas; Tarjan, Robert Endre; Werneck, Renato Fonseca F.

    2006-01-01

    Motivated by an application in computational topology, we consider a novel variant of the problem of efficiently maintaining dynamic rooted trees. This variant allows an operation that merges two tree paths. In contrast to the standard problem, in which only one tree arc at a time changes, a sing...

  17. Poplus Diversifolia:The Most Beautiful Tree

    Institute of Scientific and Technical Information of China (English)

    ZhanHua

    2004-01-01

    Populus diversifolia,an old and rare tree species,is an only tree variety that can naturally grow into forest in Xinjiang's deserts.It is called "Tokolako"in the Uigur language,meaning"the most beautiful tree".Its extraordinary resistance to drought,sand wind and sanitization enables it to thrive in deserts and gains it repute

  18. QDist—Quartet Distance Between Evolutionary Trees

    DEFF Research Database (Denmark)

    Mailund; Pedersen, Christian N. Storm

    2004-01-01

    QDist is a program for computing the quartet distance between two unrooted evolutionary trees, i.e. the number of quartet topology differences between the two trees, where a quartet topology is the topological subtree induced by four species. The implementation is based on an algorithm with running...... time O(n log² n), which makes it practical to compare large trees....

  19. Vessel tree extraction using locally optimal paths

    DEFF Research Database (Denmark)

    Lo, P.; Ginneken, B. van; Bruijne, M. de

    2010-01-01

    of the vessel tree. Experiments were performed on 10 low dose chest CT scans for which the pulmonary vessel trees were extracted. The proposed method is shown to extract a better connected vessel tree and extract more of the small peripheral vessels in comparison to applying a threshold on the output...

  20. Navigation and Tree Mapping in Orchards

    DEFF Research Database (Denmark)

    Jæger-Hansen, Claes Lund; Griepentrog, Hans W.; Andersen, Jens Christian

    In this paper an algorithm for estimating tree positions is presented. The sensors used for the algorithm is GNSS and LIDAR, and data is collected in an orchard with grapefruit trees while driving along the rows. The positions of the trees are estimated using ellipse fitting on point clouds. The ...... and localization for an autonomous robot....

  1. Tree-space statistics and approximations for large-scale analysis of anatomical trees

    DEFF Research Database (Denmark)

    Feragen, Aasa; Owen, Megan; Petersen, Jens;

    2013-01-01

    parametrize the relevant parts of tree-space well. Using the developed approximate statistics, we illustrate how the structure and geometry of airway trees vary across a population and show that airway trees with Chronic Obstructive Pulmonary Disease come from a different distribution in tree-space than...

  2. Shedding light on tree growth : ring analysis of juvenile tropical trees

    NARCIS (Netherlands)

    Soliz Gamboa, C.C.

    2010-01-01

    In the understory of tropical forests light is believed to be the main limiting growth factor for the newly established trees. Trees growing in shade of the understory may experience periods of slow radial growth. It is expected that gaps created by tree or branch fall will provoke tree growth relea

  3. Sleeping tree choice by Bwindi chimpanzees.

    Science.gov (United States)

    Stanford, Craig B; O'Malley, Robert C

    2008-07-01

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

  4. Tree decompositions and social graphs

    CERN Document Server

    Adcock, Aaron B; Mahoney, Michael W

    2014-01-01

    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 "...

  5. Logical Tree of Mathematical Modeling

    Directory of Open Access Journals (Sweden)

    László Pokorádi

    2015-04-01

    Full Text Available During setting up a mathematical model, it can be very important and dicult task to choose input parametersthat should be known for solution of this problem. A similar problem might come up when someone wants to carryout an engineering calculation task. A very essential aim technical education is developing of good logical engineeringthinking. One main part of this thinking is to determine the potential sets of required input parameters of anengineering calculation. This paper proposes a logical tree based method to determine the required parameters of amathematical model. The method gives a lively description about needed data base, and computational sequence forus to get to determine the set of required output parameter. The shown method is named LogTreeMM - Logical Treeof Mathematical Modeling.

  6. The Structural Optimization of Trees

    Science.gov (United States)

    Mattheck, C.; Bethge, K.

    1998-01-01

    Optimization methods are presented for engineering design based on the axiom of uniform stress. The principle of adaptive growth which biological structures use to minimize stress concentrations has been incorporated into a computer-aided optimization (CAO) procedure. Computer-aided optimization offers the advantage of three-dimensional optimization for the purpose of designing more fatigue-resistant components without mathematical sophistication. Another method, called computer-aided internal optimization (CAIO), optimizes the performance of fiber-composite materials by aligning the fiber distribution with the force flow, again mimicking the structure of trees. The lines of force flow, so-called principal stress trajectories, are not subject to shear stresses. Avoiding shear stresses in the technical components can lead to an increase in maximum load capacity. By the use of a new testing device strength distributions in trees can be determined and explained based on a new mechanical wood model.

  7. Reweighting with Boosted Decision Trees

    CERN Document Server

    Rogozhnikov, A

    2016-01-01

    Machine learning tools are commonly used in modern high energy physics (HEP) experiments. Different models, such as boosted decision trees (BDT) and artificial neural networks (ANN), are widely used in analyses and even in the software triggers. In most cases, these are classification models used to select the "signal" events from data. Monte Carlo simulated events typically take part in training of these models. While the results of the simulation are expected to be close to real data, in practical cases there is notable disagreement between simulated and observed data. In order to use available simulation in training, corrections must be introduced to generated data. One common approach is reweighting - assigning weights to the simulated events. We present a novel method of event reweighting based on boosted decision trees. The problem of checking the quality of reweighting step in analyses is also discussed.

  8. Household Tree Planting in Tigrai, Northern Ethiopia: Tree Species, Purposes, and Determinants

    OpenAIRE

    Gebreegziabher, Zenebe; Mekonnen, Alemu; Kassie, Menale; Köhlin, Gunnar

    2010-01-01

    Trees have multiple purposes in rural Ethiopia, providing significant economic and ecological benefits. Planting trees supplies rural households with wood products for their own consumption, as well for sale, and decreases soil degradation. We used cross-sectional household-level data to analyze the determinants of household tree planting and explored the most important tree attributes or purpose(s) that enhance the propensity to plant trees. We set up a sample selection framework that simult...

  9. Discrimination method of forked larch trees

    Institute of Scientific and Technical Information of China (English)

    Li Wen-bin; Sun Ren-shan; Liu Xu-hua; Liu Yong

    2006-01-01

    For the demands of automatíc pruning, an effective discrimination rule of the forked and non-forked larch trees is established. First, information of trunk and branch diameters of a larch plantations was collected from the west mountain of Beijing. The growth characteristics of the forked and non-forked trees were studied. Given the statistical characteristics of the trunk and branch diameters, a discriminant function of the forked branch and non-forked larch trees was established statistically. Excellent discrimination results were obtained by the function and the rule. The study presents an effective discrimination rule to separate forked trees from straight trees for automatic pruning.

  10. Hyperdominance in the Amazonian tree flora

    OpenAIRE

    H. ter Steege; Pitman, N.C.A.; Sabatier, D.; Baraloto, C.; Salomao, R. P.; Guevara, J. E.; Phillips, O. L; Castilho, C. V.; Magnusson, W.E.; Molino, J.-F.; A. Monteagudo; Nunez Vargas, P.; Montero, J. C.; Feldpausch, T. R.; Coronado, E. N. H.

    2013-01-01

    The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habi...

  11. Survey: Information flow on trees

    OpenAIRE

    Mossel, Elchanan

    2004-01-01

    Consider a tree network T, where each edge acts as an independent copy of a given channel M, and information is propagated from the root. For which T and M does the configuration obtained at level n of T typically contain significant information on the root variable? This model appeared independently in biology, information theory, and statistical physics. Its analysis uses techniques from the theory of finite markov chains, statistics, statistical physics, information theory, cryptography an...

  12. Behaviour Trees for Evolutionary Robotics

    OpenAIRE

    Scheper, Kirk Y. W.; Tijmons, Sjoerd; de Visser, Coen C.; de Croon, Guido C. H. E.

    2014-01-01

    Evolutionary Robotics allows robots with limited sensors and processing to tackle complex tasks by means of sensory-motor coordination. In this paper we show the first application of the Behaviour Tree framework to a real robotic platform using the Evolutionary Robotics methodology. This framework is used to improve the intelligibility of the emergent robotic behaviour as compared to the traditional Neural Network formulation. As a result, the behaviour is easier to comprehend and manually ad...

  13. Cherry Tree Restaurant: Dessert Menu

    OpenAIRE

    Cherry Tree Restaurant

    2012-01-01

    The Cherry Tree restaurant was opened by chef/proprietor Harry McKeogh in Ballina, Co. Mayo in 2000. It is a contemporary style restaurant with waterside views. Produce is sourced from the local area where possible and a range of menus are offered from early bird to à la carte. The restaurant has won a number of awards and recommendations Restaurant website available here http://arrow.dit.ie/menus21c/1065/thumbnail.jpg

  14. Tree-dependent Component Analysis

    OpenAIRE

    Bach, Francis R.; Jordan, Michael I.

    2012-01-01

    We present a generalization of independent component analysis (ICA), where instead of looking for a linear transform that makes the data components independent, we look for a transform that makes the data components well fit by a tree-structured graphical model. Treating the problem as a semiparametric statistical problem, we show that the optimal transform is found by minimizing a contrast function based on mutual information, a function that directly extends the contrast function used for c...

  15. Numerics of implied binomial trees

    OpenAIRE

    Härdle, Wolfgang Karl; Myšičková, Alena

    2008-01-01

    Market option prices in last 20 years confirmed deviations from the Black and Scholes (BS) models assumptions, especially on the BS implied volatility. Implied binomial trees (IBT) models capture the variations of the implied volatility known as \\volatility smile". They provide a discrete approximation to the continuous risk neutral process for the underlying assets. In this paper, we describe the numerical construction of IBTs by Derman and Kani (DK) and an alternative method by Barle and Ca...

  16. Nutrient cycling in mango trees

    Directory of Open Access Journals (Sweden)

    Cinara Xavier de Almeida

    2014-02-01

    Full Text Available Estimates of nutrient amounts both shedding and demanding replacement in the maintenance of productivity of fruit trees require studies on element dynamics within the many ecosystem components generally made up of nutrient cycling. Thus, it was the objective of this study to evaluate the nutrient biochemical cycling in a mango tree (Mangifera indica L. orchard, Palmer variety. Macronutrients [nitrogen (N, phosphorus (P, potassium (K, calcium (Ca, magnesium (Mg, and sulfur (S] had their contents evaluated in leaves at different stages: new, mature, senescent, and litter. First exploratory analysis was performed for main components which preserve the multivariate structure shown by the data. It was possible to observe the association of new leaves with N, P, K, Mg, and S; senescent leaves and the leaves from the litter were associated to Ca, while mature leaves, to K. As a complement, taking the independent variables into consideration, Tukey test (p?0.01 showed that the averages of N, P, and Ca differ between the new and the mature leaves; average of Mg in new leaves differs from the others, and S does not differ along the stages. Also observed was the re-translocation of 41%, 63% and 57% of N, P, and K, respectively, when comparison was made among the contents of the elements in mature leaves as well as in litter, which indicates that the biochemical cycling is important for the mango tree cultivation.

  17. The Shapley Value of Phylogenetic Trees

    CERN Document Server

    Haake, Claus-Jochen; Su, Francis Edward

    2007-01-01

    Every weighted tree corresponds naturally to a cooperative game that we call a "tree game"; it assigns to each subset of leaves the sum of the weights of the minimal subtree spanned by those leaves. In the context of phylogenetic trees, the leaves are species and this assignment captures the diversity present in the coalition of species considered. We consider the Shapley value of tree games and suggest a biological interpretation. We determine the linear transformation M that shows the dependence of the Shapley value on the edge weights of the tree, and we also compute a null space basis of M. Both depend on the "split counts" of the tree. Finally, we characterize the Shapley value on tree games by four axioms, a counterpart to Shapley's original theorem on the larger class of cooperative games.

  18. Hyperdominance in the Amazonian tree flora.

    Science.gov (United States)

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

    2013-10-18

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

  19. VEGETATIVE RESCUE OF Anadenanthera macrocarpa TREES

    Directory of Open Access Journals (Sweden)

    Poliana Coqueiro Dias

    2015-03-01

    Full Text Available The objective of this work was to evaluate the vegetative rescue of adult Anadenanthera macrocarpa trees through the induction of epicormic shoots from tree severance and stem ringing, as well as the efficiency of cutting technique on the propagation of the species. The experimental design used was random plots, in a 2 X 2 factorial arrangement, constituted by two techniques for the induction of basal shoots (tree severance and stem ringing and cuttings types (herbaceous cuttings and semihardwoods cuttings, in four replicates and plots of 12 cuttings per repetition. The tree severance and stem ringing were efficient in the induction of basal shoots in adult A. macrocarpa trees. However, the tree severance provided higher emission of basal shoots. The herbaceous cuttings presented higher rooting percentages, independent of vegetative rescue technique. In general, we conclude that the vegetative rescue and the vegetative propagation of A. macrocarpa adult trees are technically efficient.

  20. Meta-learning in decision tree induction

    CERN Document Server

    Grąbczewski, Krzysztof

    2014-01-01

    The book focuses on different variants of decision tree induction but also describes  the meta-learning approach in general which is applicable to other types of machine learning algorithms. The book discusses different variants of decision tree induction and represents a useful source of information to readers wishing to review some of the techniques used in decision tree learning, as well as different ensemble methods that involve decision trees. It is shown that the knowledge of different components used within decision tree learning needs to be systematized to enable the system to generate and evaluate different variants of machine learning algorithms with the aim of identifying the top-most performers or potentially the best one. A unified view of decision tree learning enables to emulate different decision tree algorithms simply by setting certain parameters. As meta-learning requires running many different processes with the aim of obtaining performance results, a detailed description of the experimen...

  1. On finding minimum-diameter clique trees

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  2. «Teach yourself instant German» con el famoso método «Merry Christmas allerseits» de Udo Jürgens

    Directory of Open Access Journals (Sweden)

    Miguel Turrión

    2011-12-01

    Full Text Available El fundamento teórico de esta contribución es que parece lógico en el presente número dedicado a la lengua alemana ofrecer a nuestros lectores los rudimentos de este idioma, con el objetivo de que puedan apreciar más en profundidad las sutilezas de los diversos artículos del monográfico. Presentamos aquí un texto que recorre los elementos indispensables hoy para abordar la lengua de Goethe. Dado que la metodología empleada es el recurso a la canción de autor, invitamos encarecidamente a los interesados a buscar la música en Internet, como complemento a la base documental. Es condición previa tener adecuados conocimientos de inglés. --------------------------------------------------- Teach yourself instant German with Udo Jürgens' famous method «Merry Christmas allerseits». The theoretical basis for the present contribution is that, in the current issue devoted to German, it would seem appropriate to present to our readers the basics of the language, so as to enable them better to appreciate the subtleties of the different articles contained in this Monograph. We present here a text that covers all the basic elements that today's readers require to approach the language of Goethe. Given that the methodology employed is the world of songwriting, we warmly invite interested readers to look the music up in Internet as a complement to the documentary background. Adequate knowledge of English is a prerequisite.

  3. A polynomial time algorithm for calculating the probability of a ranked gene tree given a species tree

    OpenAIRE

    Stadler, Tanja; Degnan, James H

    2012-01-01

    Background The ancestries of genes form gene trees which do not necessarily have the same topology as the species tree due to incomplete lineage sorting. Available algorithms determining the probability of a gene tree given a species tree require exponential computational runtime. Results In this paper, we provide a polynomial time algorithm to calculate the probability of a ranked gene tree topology for a given species tree, where a ranked tree topology is a tree topology with the internal v...

  4. 75 FR 66125 - Notice of Public Meeting and Request for Comments

    Science.gov (United States)

    2010-10-27

    ..., Interior. ACTION: Notice/Request for Public Meeting and Public Comments--The National Christmas Tree... suggestions on the planning of the 2010 National Christmas Tree Lighting and the subsequent 23 day event... seeking public comments and suggestions on the planning of the 2010 National Christmas Tree Lighting...

  5. 76 FR 78610 - Notice of Intent To Suspend the Nursery Production, the Nursery and Floriculture Chemical Use...

    Science.gov (United States)

    2011-12-19

    ... and Floriculture Chemical Use, and the Christmas Tree Production Surveys and All Associated Reports... Service (NASS) to suspend currently approved information collections for all Nursery and Christmas Tree... Christmas Tree Production Surveys Along with the Nursery and Floriculture Chemical Use Survey and...

  6. 76 FR 66082 - Notice of Public Meeting and Request for Comments

    Science.gov (United States)

    2011-10-25

    ..., Interior. ACTION: Notice/Request for Public Meeting and Public Comments--The National Christmas Tree... suggestions on the planning of the 2011 National Christmas Tree Lighting and the subsequent 31 day event... seeking public comments and suggestions on the planning of the 2011 National Christmas Tree Lighting...

  7. MixtureTree annotator: a program for automatic colorization and visual annotation of MixtureTree.

    Directory of Open Access Journals (Sweden)

    Shu-Chuan Chen

    Full Text Available The MixtureTree Annotator, written in JAVA, allows the user to automatically color any phylogenetic tree in Newick format generated from any phylogeny reconstruction program and output the Nexus file. By providing the ability to automatically color the tree by sequence name, the MixtureTree Annotator provides a unique advantage over any other programs which perform a similar function. In addition, the MixtureTree Annotator is the only package that can efficiently annotate the output produced by MixtureTree with mutation information and coalescent time information. In order to visualize the resulting output file, a modified version of FigTree is used. Certain popular methods, which lack good built-in visualization tools, for example, MEGA, Mesquite, PHY-FI, TreeView, treeGraph and Geneious, may give results with human errors due to either manually adding colors to each node or with other limitations, for example only using color based on a number, such as branch length, or by taxonomy. In addition to allowing the user to automatically color any given Newick tree by sequence name, the MixtureTree Annotator is the only method that allows the user to automatically annotate the resulting tree created by the MixtureTree program. The MixtureTree Annotator is fast and easy-to-use, while still allowing the user full control over the coloring and annotating process.

  8. MixtureTree annotator: a program for automatic colorization and visual annotation of MixtureTree.

    Science.gov (United States)

    Chen, Shu-Chuan; Ogata, Aaron

    2015-01-01

    The MixtureTree Annotator, written in JAVA, allows the user to automatically color any phylogenetic tree in Newick format generated from any phylogeny reconstruction program and output the Nexus file. By providing the ability to automatically color the tree by sequence name, the MixtureTree Annotator provides a unique advantage over any other programs which perform a similar function. In addition, the MixtureTree Annotator is the only package that can efficiently annotate the output produced by MixtureTree with mutation information and coalescent time information. In order to visualize the resulting output file, a modified version of FigTree is used. Certain popular methods, which lack good built-in visualization tools, for example, MEGA, Mesquite, PHY-FI, TreeView, treeGraph and Geneious, may give results with human errors due to either manually adding colors to each node or with other limitations, for example only using color based on a number, such as branch length, or by taxonomy. In addition to allowing the user to automatically color any given Newick tree by sequence name, the MixtureTree Annotator is the only method that allows the user to automatically annotate the resulting tree created by the MixtureTree program. The MixtureTree Annotator is fast and easy-to-use, while still allowing the user full control over the coloring and annotating process.

  9. Public Reactions to New Street Tree Planting

    Directory of Open Access Journals (Sweden)

    Ruth A. Rae

    2010-01-01

    Full Text Available MillionTreesNYC, which has the goal of planting one million trees in New York City by 2017, is intended to make New York City a greener, more sustainable city and is part of the Mayor’s comprehensive long term strategic plan, PlaNYC. Through planting a tree at every suitable sidewalk location in the city, the City of New York is transforming blocks and communities, and providing a variety of environmental, social and aesthetic benefits. This article examines the large scale municipal planting of new street trees and the reaction by some of the pubic to this planting.Trees offer benefits to the city overall, but the public may not understand these benefits or the street tree planting process. Between 2007 and 2009, the Department of Parks & Recreation planted 53,235 new street trees, and received 4,108 items of correspondence from the public. The majority of this correspondence consisted of public comments about the City’s new street tree planting policies and processes including placement objections, maintenance concerns, reports of resultant damage from tree planting operations, requests for new street trees and reports of tree conditions.This study describes the operational policies that guide New York City's municipal street tree planting, and results of content and spatial analysis of the correspondence. Qualitative analysis of the correspondence revealed the public perceptions and concerns related to the MillionTreesNYC program. Spatial analysis explored the relationship between the planting locations of new street trees and the locations of the citizen correspondence.Public reactions to this large scale municipal planting are related to the dual public and private nature of the sidewalk, issues of territoriality, responsibility, aesthetics and place attachment. Correspondence volume was associated with the scale of the new street tree block planting program, and the effectiveness of NYC’s 311 Customer Service Center. The discussion

  10. Agriculture, Nurseries and Ornamentals, DATCP licensed nursery and christmas tree facilities, Published in 2009, 1:24000 (1in=2000ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Agriculture, Nurseries and Ornamentals dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is...

  11. Agriculture, Nurseries and Ornamentals, DATCP licensed nurseries and christmas tree farms., Published in 2009, 1:24000 (1in=2000ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Agriculture, Nurseries and Ornamentals dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is...

  12. Assessment of student conceptions of evolutionary trees

    Science.gov (United States)

    Blacquiere, Luke

    Biologists use evolutionary trees to depict hypotheses about the relationships among taxa. Trees possess lines that represent lineages, internal nodes that represent where lineages become evolutionarily isolated from one another and terminal nodes that represent the taxa under consideration. Interpreting a tree (i.e., "tree-thinking") is an important skill for biologists yet many students struggle when reading evolutionary trees. Common documented misconceptions include using morphological similarity, internal node counting or terminal node proximity, instead of identifying the internal node that represents a most recent common ancestor (MRCA), to determine relationships among taxa. I developed an instrument to assess whether students were using common ancestry or another, non-scientific, strategy to determine relationships among taxa. The study is the first to explicitly test hypotheses about how students approach reading evolutionary trees. To test the hypotheses an instrument was developed. The instrument is the first reliable and valid assessment testing student understanding of how to use most recent common ancestor to interpret evolutionary relationships in tree diagrams. Instructors can use the instrument as a diagnostic tool enabling them to help students learn this challenging concept. This study shows that, contrary to the assertion that students hold misconceptions about evolutionary trees made in the literature, students do not consistently use erroneous strategies when interpreting trees. This study suggests that a constructivist perspective of cognitive structure describes students' conception of evolutionary trees more closely than a misconception perspective.

  13. The dynamics of strangling among forest trees.

    Science.gov (United States)

    Okamoto, Kenichi W

    2015-11-01

    Strangler trees germinate and grow on other trees, eventually enveloping and potentially even girdling their hosts. This allows them to mitigate fitness costs otherwise incurred by germinating and competing with other trees on the forest floor, as well as minimize risks associated with host tree-fall. If stranglers can themselves host other strangler trees, they may not even seem to need non-stranglers to persist. Yet despite their high fitness potential, strangler trees neither dominate the communities in which they occur nor is the strategy particularly common outside of figs (genus Ficus). Here we analyze how dynamic interactions between strangling and non-strangling trees can shape the adaptive landscape for strangling mutants and mutant trees that have lost the ability to strangle. We find a threshold which strangler germination rates must exceed for selection to favor the evolution of strangling, regardless of how effectively hemiepiphytic stranglers may subsequently replace their hosts. This condition describes the magnitude of the phenotypic displacement in the ability to germinate on other trees necessary for invasion by a mutant tree that could potentially strangle its host following establishment as an epiphyte. We show how the relative abilities of strangling and non-strangling trees to occupy empty sites can govern whether strangling is an evolutionarily stable strategy, and obtain the conditions for strangler coexistence with non-stranglers. We then elucidate when the evolution of strangling can disrupt stable coexistence between commensal epiphytic ancestors and their non-strangling host trees. This allows us to highlight parallels between the invasion fitness of strangler trees arising from commensalist ancestors, and cases where strangling can arise in concert with the evolution of hemiepiphytism among free-standing ancestors. Finally, we discuss how our results can inform the evolutionary ecology of antagonistic interactions more generally.

  14. Nitrogen fixation in trees - 1

    Energy Technology Data Exchange (ETDEWEB)

    Dobereiner, J.; Gauthier, D.L.; Diem, H.G.; Dommergues, Y.R.; Bonetti, R.; Oliveira, L.A.; Magalhaes, F.M.M.; Faria, S.M. de; Franco, A.A.; Menandro, M.S.

    1984-01-01

    Six papers are presented from the symposium. Dobereiner, J.; Nodulation and nitrogen fixation in leguminous trees, 83-90, (15 ref.), reviews studies on Brazilian species. Gauthier, D.L., Diem, H.G., Dommergues, Y.R., Tropical and subtropical actinorhizal plants, 119-136, (Refs. 50), reports on studies on Casuarinaceae. Bonetti, R., Oliveira, L.A., Magalhaes, F.M.M.; Rhizobium populations and occurrence of VA mycorrhizae in plantations of forest trees, 137-142, (Refs. 15), studies Amazonia stands of Cedrelinga catenaeformis, Calophyllum brasiliense, Dipteryx odorata, D. potiphylla, Carapa guianensis, Goupia glabra, Tabebuia serratifolia, Clarisia racemosa, Pithecellobium racemosum, Vouacapoua pallidior, Eperua bijuga, and Diplotropis species. Nodulation was observed in Cedrelinga catenaeformis and V. pallidior. Faria, S.M. de, Franco, A.A., Menandro, M.S., Jesus, R.M. de, Baitello, J.B.; Aguiar, O.T. de, Doebereiner, J; survey of nodulation in leguminous tree species native to southeastern Brazil, 143-153, (Refs. 7), reports on 119 species, with first reports of nodulation in the genera Bowdichia, Poecilanthe, Melanoxylon, Moldenhaurea (Moldenhawera), and Pseudosamanea. Gaiad, S., Carpanezzi, A.A.; Occurrence of Rhizobium in Leguminosae of silvicultural interest for south Brazil, 155-158, (Refs. 2). Nodulation is reported in Mimosa scabrella, Acacia mearnsii, A. longifolia various trinervis, Enterolobium contortisiliquum, and Erythrina falcata. Magalhaes, L.M.S., Blum, W.E.H., Nodulation and growth of Cedrelinga catanaeformis in experimental stands in the Manaus region - Amazonas, 159-164, (Refs. 5). Results indicate that C. catenaeformis can be used in degraded areas of very low soil fertility.

  15. Phytoremediation of trichloroethene (TCE) using cottonwood trees

    Science.gov (United States)

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

    1999-01-01

    The ability of cottonwood trees for phytoremediation was studied on aerobic shallow groundwater containing TCE. Cottonwood trees were planted over a 0.2-ha area at the Naval Air Station at Fort Worth, TX, in April 1996. Two years later, groundwater chemistry in the terrace alluvial aquifer was changing locally. Dissolved oxygen (DO) concentrations declined at the southern end of the whip plantings while total iron concentration increased. Groundwater chemistry near a mature cottonwood tree ~ 60 m from the caliper trees was different from that observed elsewhere. Anaerobic conditions near the mature cottonwood tree were evident. Reductive dechlorination of TCE occurred in the aquifer near the mature tree, as demonstrated by very small concentration of TCE in groundwater, a small median ratio of TCE to the degradation product cis-1,2-DCE and the presence of vinyl chloride.

  16. Affine and Projective Tree Metric Theorems

    CERN Document Server

    Harel, Matan; Pachter, Lior

    2011-01-01

    The tree metric theorem provides a combinatorial four point condition that characterizes dissimilarity maps derived from pairwise compatible split systems. A similar (but weaker) four point condition characterizes dissimilarity maps derived from circular split systems (Kalmanson metrics). The tree metric theorem was first discovered in the context of phylogenetics and forms the basis of many tree reconstruction algorithms, whereas Kalmanson metrics were first considered by computer scientists, and are notable in that they are a non-trivial class of metrics for which the traveling salesman problem is tractable. We present a unifying framework for these theorems based on combinatorial structures that are used for graph planarity testing. These are (projective) PC-trees, and their affine analogs, PQ-trees. In the projective case, we generalize a number of concepts from clustering theory, including hierarchies, pyramids, ultrametrics and Robinsonian matrices, and the theorems that relate them. As with tree metric...

  17. Partitioning Complete Graphs by Heterochromatic Trees

    Institute of Scientific and Technical Information of China (English)

    Ze-min JIN; Xue-liang LI

    2012-01-01

    A heterochromatic tree is an edge-colored tree in which any two edges have different colors.The heterochroratic tree partition number of an r-edge-colored graph G,denoted by tr(G),is the minimum positive integer p such that whenever the edges of the graph G are colored with r colors,the vertices of G can be covered by at most p vertex-disjoint heterochromatic trees.In this paper we determine the heterochromatic tree partition number of r-edge-colored complete graphs.We also find at most tr(Kn) vertex-disjoint heterochromatic trees to cover all the vertices in polynomial time for a given r-edge-coloring of Kn.

  18. Top-down induction of clustering trees

    OpenAIRE

    Blockeel, Hendrik; De Raedt, Luc; Ramon, Jan

    2000-01-01

    An approach to clustering is presented that adapts the basic top-down induction of decision trees method towards clustering. To this aim, it employs the principles of instance based learning. The resulting methodology is implemented in the TIC (Top down Induction of Clustering trees) system for first order clustering. The TIC system employs the first order logical decision tree representation of the inductive logic programming system Tilde. Various experiments with TIC are presented, in both ...

  19. Modeling human population patterns on tree density

    OpenAIRE

    M. Yousefpoor; Rostamie Shahraji, T; Eslam Bonyad, A; Salahi, M

    2016-01-01

    In order to evaluate the possible correlation between the tree density and the human population density, the forested area in Nav Asalem district located in Guilan Province was selected. The descriptors of tree number and basal area per hectare as well as the stand density index were used to determine the tree density, which was conducted from a 2014 forest inventory including 62 cluster (558 plots) systematically scattered over 30 % of the forest area. In addition, to determine the density o...

  20. Edit Distance between Unlabeled Ordered Trees

    OpenAIRE

    Micheli, Anne; Rossin, Dominique

    2005-01-01

    There exists a bijection between one stack sortable permutations --permutations which avoid the pattern $231$-- and planar trees. We define an edit distance between permutations which is coherent with the standard edit distance between trees. This one-to-one correspondence yields a polynomial algorithm for the subpermutation problem for $(231)$ avoiding permutations. Moreover, we obtain the generating function of the edit distance between ordered trees and some special ones. For the general c...

  1. Minimum Dominating Tree Problem for Graphs

    Institute of Scientific and Technical Information of China (English)

    LIN Hao; LIN Lan

    2014-01-01

    A dominating tree T of a graph G is a subtree of G which contains at least one neighbor of each vertex of G. The minimum dominating tree problem is to find a dominating tree of G with minimum number of vertices, which is an NP-hard problem. This paper studies some polynomially solvable cases, including interval graphs, Halin graphs, special outer-planar graphs and others.

  2. Street Tree Diversification and Location Considerations

    OpenAIRE

    Farley, Jeran

    2013-01-01

    Although essential in an urban forest, street trees create numerous challenges for municipalities as well as private owners. Lack of species diversity is usually pronounced. In addition, inappropriate species are commonly planted along streets. Selection of street trees should follow established percentage guidelines for tree species, genera, and family in order to maintain diversity when planting in a municipality. Numerous variables such as proximity to buildings or vehicular traffic, soil ...

  3. 16 Less Common Trees for Utah Landscapes

    OpenAIRE

    Kratsch, Heidi; Kuhns, Michael

    2006-01-01

    Utah towns and cities are fairly harsh places to grow trees, leading people to think that only a few tough species can be grown here. This attitude seems to lead to the over-planting of a fairly narrow selection of low- to medium-quality trees – a handful of maples, too many cottonwoods and willows, Siberian elm, etc. Yet there are many tree species that have proven themselves in Utah’s urban environments, but that are little known.

  4. Option Implied Trees and Implied Moments

    OpenAIRE

    silvia Muzzioli; Alessio Ruggieri

    2013-01-01

    Implied trees are simple non-parametric discretizations of one- or two-dimension diffusions, aimed at introducing non-constant volatility in an option pricing model. The aim of the paper is twofold. First we investigate the ability of different option implied trees in pricing European options. Second, we compare the implied moments obtained with the use of option implied trees with the risk–neutral moments obtained with the use of Bakshi et al. (2003) formula and with realised physical moment...

  5. Linear Context-Free Tree Languages and Inverse Homomorphisms

    OpenAIRE

    Osterholzer, Johannes; Dietze, Toni; Herrmann, Luisa

    2015-01-01

    We prove that the class of linear context-free tree languages is not closed under inverse linear tree homomorphisms. The proof is by contradiction: we encode Dyck words into a context-free tree language and prove that its preimage under a certain linear tree homomorphism cannot be generated by any context-free tree grammar. A positive result can still be obtained: the linear monadic context-free tree languages are closed under inverse linear tree homomorphisms.

  6. Computer aided fault tree synthesis

    International Nuclear Information System (INIS)

    Nuclear as well as non-nuclear organisations are showing during the past few years a growing interest in the field of reliability analysis. This urges for the development of powerful, state of the art methods and computer codes for performing such analysis on complex systems. In this report an interactive, computer aided approach is discussed, based on the well known fault tree technique. The time consuming and difficut task of manually constructing a system model (one or more fault trees) is replaced by an efficient interactive procedure in which the flexibility and the learning process inherent to the manual approach are combined with the accuracy in the modelling and the speed of the fully automatical approach. The method presented is based upon the use of a library containing component models. The possibility of setting up a standard library of models of general use and the link with a data collection system are discussed. The method has been implemented in the CAFTS-SALP software package which is described shortly in the report

  7. Betweenness centrality profiles in trees

    CERN Document Server

    Fish, Benjamin; Turan, Gyorgy

    2016-01-01

    Betweenness centrality of a vertex in a graph measures the fraction of shortest paths going through the vertex. This is a basic notion for determining the importance of a vertex in a network. The k-betweenness centrality of a vertex is defined similarly, but only considers shortest paths of length at most k. The sequence of k-betweenness centralities for all possible values of k forms the betweenness centrality profile of a vertex. We study properties of betweenness centrality profiles in trees. We show that for scale-free random trees, for fixed k, the expectation of k-betweenness centrality strictly decreases as the index of the vertex increases. We also analyze worst-case properties of profiles in terms of the distance of profiles from being monotone, and the number of times pairs of profiles can cross. This is related to whether k-betweenness centrality, for small values of k, may be used instead of having to consider all shortest paths. Bounds are given that are optimal in order of magnitude. We also pre...

  8. Ash basin reclamation with forest trees

    Energy Technology Data Exchange (ETDEWEB)

    Horton, J.H.; McMinn, J.W.

    1977-09-01

    An ash basin at the Savannah River Plant, Aiken, South Carolina is growing trees as well as, and with some species better than, a local soil. The basin contains ashes from a stoker-fed boiler and was last used about 12 years before the trees were planted. The concentrations of 24 chemical elements were measured in ashes, soil and trees. The concentrations of most of the chemical elements were higher in ashes than in soil; however, with a few exceptions, these elements were less available to the trees on ashes than to the trees on soil. The trees do not show any toxicity or deficiency symptoms, but the concentration of manganese in sycamore growing on ashes indicates a possible deficiency. No concentration of an element in trees appears to be high enough to be toxic to the trees. A longer period of study will be required to determine whether the ashes can produce commercial timber, but trees can be used to stabilize ash basins and improve their appearance.

  9. Belowground carbon trade among tall forest trees

    Science.gov (United States)

    Klein, Tamir; Siegwolf, Rolf; Koerner, Christian

    2016-04-01

    Just imagine one tree could hand over large quantities of carbon to another tree. How would that change our thinking about carbon relations of forests, the single biggest biological C reservoir on earth? If such a tree-to-tree C shuttle would exist, it required a demand-supply gradient and a pipeline. Here we show that exactly this unthinkable does occur in overlapping root spheres of tall trees in a mixed temperate forest. Using canopy scale stable carbon isotope labelling applied from a construction crane, we demonstrate that carbon assimilated by spruce is traded over to neighbouring beech, larch, and pine in amounts so large that fine roots almost equilibrate the carbon source signature. The isotope mixing ratio indicated that the interspecific transfer accounted for 40% of the fine root carbon, which is ca. 280 kg ha-1 a-1. This is the first forest scale evidence of a large flux of carbon among mature trees from evolutionary distant taxa. Carbon transfer most likely occurred through common ectomycorrhiza networks, which also exhibited the labelled carbon signal. These observations indicate that while competition for resources (e.g. light, water, nutrients) is often considered the dominant tree-tree interaction in a forest, trees actually interact in more complex pathways including a massive carbon exchange.

  10. Cluster Tree Based Hybrid Document Similarity Measure

    Directory of Open Access Journals (Sweden)

    M. Varshana Devi

    2015-10-01

    Full Text Available tree based hybrid similarity measure is established to measure the hybrid similarity. In cluster tree, the hybrid similarity measure can be calculated for the random data even it may not be the co-occurred and generate different views. Different views of tree can be combined and choose the one which is significant in cost. A method is proposed to combine the multiple views. Multiple views are represented by different distance measures into a single cluster. Comparing the cluster tree based hybrid similarity with the traditional statistical methods it gives the better feasibility for intelligent based search. It helps in improving the dimensionality reduction and semantic analysis.

  11. Community assessment of tropical tree biomass

    DEFF Research Database (Denmark)

    Theilade, Ida; Rutishauser, Ervan; Poulsen, Michael K.

    2015-01-01

    communities have rarely been assessed in the tropics. The aim of this study was to investigate different sources of error in tree biomass measurements conducted by community monitors and determine the effect on biomass estimates. Furthermore, we explored the potential of local ecological knowledge to assess...... previous experience. Indeed, only experienced monitors were able to discriminate trees with low wood densities. Local ecological knowledge did not allow consistent tree identification across monitors. Conclusion Future REDD+ programmes may benefit from the systematic training of local monitors in tree DBH...

  12. Tree of life and its applications

    Directory of Open Access Journals (Sweden)

    Limin Lu

    2014-01-01

    Full Text Available The term “Tree of Life” was first used by Charles Darwin in 1859 as a metaphor for describing phylogenetic relationships among organisms. Over the past three decades, the recognized tree of life has improved considerably in overall size and reliability due to an increase in diversity of character resources, a dramatic growth in useable data, and the development of tree-reconstruction methods. As a bridge connecting phylogeny, evolution and related disciplines, such as molecular biology, ecology, genomics, bioinformatics and computer science, the tree of life is increasingly widely used. In this paper, we review the history and progress of tree of life studies and focus on its application in the following fields: (1 the reconstruction of phylogenetic trees at different taxonomic hierarchies to understand phylogenetic relationships among taxa; (2 investigation of the origins of taxa and biogeographic patterns based on dating estimation and biogeographic reconstruction; (3 examination of species’ diversification and its causes by integrating dated trees, ecological factors, environmental variation and key innovations; (4 the study of the origin and patterns of biodiversity, predating biodiversity dynamics, and development of conservation strategies. Finally, we evaluate the difficulties from matrix alignment, gene tree incongruence and “rogue taxa” distraction in tree reconstruction due to massive increases of useable data and in the context consider “supertree” building in the future.

  13. The space of ultrametric phylogenetic trees.

    Science.gov (United States)

    Gavryushkin, Alex; Drummond, Alexei J

    2016-08-21

    The reliability of a phylogenetic inference method from genomic sequence data is ensured by its statistical consistency. Bayesian inference methods produce a sample of phylogenetic trees from the posterior distribution given sequence data. Hence the question of statistical consistency of such methods is equivalent to the consistency of the summary of the sample. More generally, statistical consistency is ensured by the tree space used to analyse the sample. In this paper, we consider two standard parameterisations of phylogenetic time-trees used in evolutionary models: inter-coalescent interval lengths and absolute times of divergence events. For each of these parameterisations we introduce a natural metric space on ultrametric phylogenetic trees. We compare the introduced spaces with existing models of tree space and formulate several formal requirements that a metric space on phylogenetic trees must possess in order to be a satisfactory space for statistical analysis, and justify them. We show that only a few known constructions of the space of phylogenetic trees satisfy these requirements. However, our results suggest that these basic requirements are not enough to distinguish between the two metric spaces we introduce and that the choice between metric spaces requires additional properties to be considered. Particularly, that the summary tree minimising the square distance to the trees from the sample might be different for different parameterisations. This suggests that further fundamental insight is needed into the problem of statistical consistency of phylogenetic inference methods. PMID:27188249

  14. The combinatorics of tandem duplication trees.

    Science.gov (United States)

    Gascuel, Olivier; Hendy, Michael D; Jean-Marie, Alain; McLachlan, Robert

    2003-02-01

    We developed a recurrence relation that counts the number of tandem duplication trees (either rooted or unrooted) that are consistent with a set of n tandemly repeated sequences generated under the standard unequal recombination (or crossover) model of tandem duplications. The number of rooted duplication trees is exactly twice the number of unrooted trees, which means that on average only two positions for a root on a duplication tree are possible. Using the recurrence, we tabulated these numbers for small values of n. We also developed an asymptotic formula that for large n provides estimates for these numbers. These numbers give a priori probabilities for phylogenies of the repeated sequences to be duplication trees. This work extends earlier studies where exhaustive counts of the numbers for small n were obtained. One application showed the significance of finding that most maximum-parsimony trees constructed from repeat sequences from human immunoglobins and T-cell receptors were tandem duplication trees. Those findings provided strong support to the proposed mechanisms of tandem gene duplication. The recurrence relation also suggests efficient algorithms to recognize duplication trees and to generate random duplication trees for simulation. We present a linear-time recognition algorithm.

  15. Combinatorics of distance-based tree inference.

    Science.gov (United States)

    Pardi, Fabio; Gascuel, Olivier

    2012-10-01

    Several popular methods for phylogenetic inference (or hierarchical clustering) are based on a matrix of pairwise distances between taxa (or any kind of objects): The objective is to construct a tree with branch lengths so that the distances between the leaves in that tree are as close as possible to the input distances. If we hold the structure (topology) of the tree fixed, in some relevant cases (e.g., ordinary least squares) the optimal values for the branch lengths can be expressed using simple combinatorial formulae. Here we define a general form for these formulae and show that they all have two desirable properties: First, the common tree reconstruction approaches (least squares, minimum evolution), when used in combination with these formulae, are guaranteed to infer the correct tree when given enough data (consistency); second, the branch lengths of all the simple (nearest neighbor interchange) rearrangements of a tree can be calculated, optimally, in quadratic time in the size of the tree, thus allowing the efficient application of hill climbing heuristics. The study presented here is a continuation of that by Mihaescu and Pachter on branch length estimation [Mihaescu R, Pachter L (2008) Proc Natl Acad Sci USA 105:13206-13211]. The focus here is on the inference of the tree itself and on providing a basis for novel algorithms to reconstruct trees from distances.

  16. Concurrent Manipulation of Expanded AVL Trees

    Institute of Scientific and Technical Information of China (English)

    章寅; 许卓群

    1998-01-01

    The concurrent manipulation of an expanded AVL tree(EAVL tree)s considered in this paper.The presented system can support any number of concurrent processes which perform searching,insertion and deletion on the tree.Simulation results indicate the high performance of the system.Elaborate techniques are used to achieve such a system unavailable based on any known algorithms.Methods developed in this paper may provide new insights into other problems in the area of concurrent search structure manipulation.

  17. The irregularity of two types of trees

    OpenAIRE

    Liu, Yang; Li, Jianxi; Chee, Wai

    2015-01-01

    The irregularity of a graph G is defined as the sum of weights |d(u) − d(v)| of all edges uv of G, where d(u) and d(v) are the degrees of the vertices u and v in G, respectively. In this paper, some structural properties on trees with maximum (or minimum) irregularity among trees with given degree sequence and trees with given branching number are explored, respectively. Moreover, the corresponding trees with maximum (or minimum) irregularity are also found, respectively.

  18. Making CSB+-Tree Processor Conscious

    DEFF Research Database (Denmark)

    Samuel, Michael; Pedersen, Anders Uhl; Bonnet, Philippe

    2005-01-01

    Cache-conscious indexes, such as CSB+-tree, are sensitive to the underlying processor architecture. In this paper, we focus on how to adapt the CSB+-tree so that it performs well on a range of different processor architectures. Previous work has focused on the impact of node size on the performan...... a systematic method for adapting CSB+-tree to new platforms. This work is a first step towards integrating CSB+-tree in MySQL’s heap storage manager....

  19. Fruit load governs transpiration of olive trees.

    Science.gov (United States)

    Bustan, Amnon; Dag, Arnon; Yermiyahu, Uri; Erel, Ran; Presnov, Eugene; Agam, Nurit; Kool, Dilia; Iwema, Joost; Zipori, Isaac; Ben-Gal, Alon

    2016-03-01

    We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from trees at three separate stages of growth: early, mid and late in the season. Tree-scale transpiration, calculated from lysimeter water balance, was found to be a function of fruit load, canopy size and weather conditions. Fruit removal caused an immediate decline in water consumption, measured as whole-plant transpiration normalized to tree size, which persisted until the end of the season. The later the execution of fruit removal, the greater was the response. The amount of water transpired by a fruit-loaded tree was found to be roughly 30% greater than that of an equivalent low- or nonyielding tree. The tree-scale response to fruit was reflected in stem water potential but was not mirrored in leaf-scale physiological measurements of stomatal conductance or photosynthesis. Trees with low or no fruit load had higher vegetative growth rates. However, no significant difference was observed in the overall aboveground dry biomass among groups, when fruit was included. This case, where carbon sources and sinks were both not limiting, suggests that the role of fruit on water consumption involves signaling and alterations in hydraulic properties of vascular tissues and tree organs.

  20. Morocco - Fruit Tree Productivity, Extension Component

    Data.gov (United States)

    Millenium Challenge Corporation — The emphasis of this performance evaluation is primarily on the economic and financial assessment of one specific activity of the Fruit Tree Productivity Project,...

  1. Multicriteria Steiner Tree Problem for Communication Network

    CERN Document Server

    Levin, Mark Sh

    2011-01-01

    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.

  2. Checklist of Recent thecideoid brachiopods from the Indian Ocean and Red Sea, with a description of a new species of Thecidellina from Europa Island and a re-description of T. blochmanni Dall from Christmas Island.

    Science.gov (United States)

    Logan, Alan; Hoffmann, Jana; Lüter, Carsten

    2015-01-01

    Compilation of a checklist of Recent thecideoid brachiopods from the Indian Ocean and Red Sea indicates that members of this superfamily are represented by a small number of species. The subfamily Lacazellinae is represented by Ospreyella maldiviana from the Maldive Islands but the presence of Lacazella cannot yet be confirmed in the Indian Ocean as the holotype of Lacazella mauritiana from Mauritius is lost. The subfamily Thecidellininae is represented by Thecidellina blochmanni from Christmas Island in the eastern Indian Ocean and the Red Sea while a new species T. europa is here described from Europa Island in the Mozambique Channel. The subfamily Minutellinae is represented by Minutella minuta from Samper Bank and Walters Bank in the south-western Indian Ocean and in the Red Sea. Since the holotype of Thecidellina blochmanni from Flying Fish Cove, Christmas Island is also lost, this species is re-described and illustrated mainly from topotypes in the Museum für Naturkunde, Berlin, from which a suggested neotype has been selected.

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

    DEFF Research Database (Denmark)

    Li, Heng; Coghlan, Avril; Ruan, Jue;

    2006-01-01

    , based on seed alignments and trees in a similar fashion to Pfam. Release 1.1 of TreeFam contains curated trees for 690 families and automatically generated trees for another 11 646 families. These represent over 128 000 genes from nine fully sequenced animal genomes and over 45 000 other animal proteins......TreeFam is a database of phylogenetic trees of gene families found in animals. It aims to develop a curated resource that presents the accurate evolutionary history of all animal gene families, as well as reliable ortholog and paralog assignments. Curated families are being added progressively...... from UniProt; approximately 40-85% of proteins encoded in the fully sequenced animal genomes are included in TreeFam. TreeFam is freely available at http://www.treefam.org and http://treefam.genomics.org.cn. Udgivelsesdato: 2006-Jan-1...

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

    Science.gov (United States)

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

    2013-02-01

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

  5. 2-Level R-tree Index Based on Spatial Grids and Hilbert R-tree

    Institute of Scientific and Technical Information of China (English)

    GUO Jing; LIU Guangjun; DONG Xurong; GUO Lei

    2006-01-01

    Multi-level spatial index techniques are always used in large spatial databases. After a general survey of R-tree relevant techniques, this paper presents a novel 2-level index structure, which is based on the schemas of spatial grids, Hilbert R-tree and common R-tree. This structure is named H2R-tree, and it is specifically suitable for the indexing highly skewed, distributed, and large spatial database. Algorithms and a sample are given subsequently.

  6. The Priority R-Tree: A Practically Efficient and Worst-Case Optimal R-tree

    DEFF Research Database (Denmark)

    Arge, Lars; de Berg, Mark; Haverkort, Herman;

    2004-01-01

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

  7. Understanding recruitment failure in tropical tree species: Insights from a tree ring study

    NARCIS (Netherlands)

    Vlam, M.; Baker, P.J.; Bunyavejchewin, S.; Mohren, G.M.J.; Zuidema, P.A.

    2014-01-01

    Many tropical tree species have population structures that exhibit strong recruitment failure. While the presence of adult trees indicates that appropriate regeneration conditions occurred in the past, it is often unclear why small individuals are absent. Knowing how, when and where these tree speci

  8. 36 CFR 223.4 - Exchange of trees or portions of trees.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Exchange of trees or portions of trees. 223.4 Section 223.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER General Provisions § 223.4 Exchange of trees...

  9. Robustness to divergence time underestimation when inferring species trees from estimated gene trees.

    Science.gov (United States)

    DeGiorgio, Michael; Degnan, James H

    2014-01-01

    To infer species trees from gene trees estimated from phylogenomic data sets, tractable methods are needed that can handle dozens to hundreds of loci. We examine several computationally efficient approaches-MP-EST, STAR, STEAC, STELLS, and STEM-for inferring species trees from gene trees estimated using maximum likelihood (ML) and Bayesian approaches. Among the methods examined, we found that topology-based methods often performed better using ML gene trees and methods employing coalescent times typically performed better using Bayesian gene trees, with MP-EST, STAR, STEAC, and STELLS outperforming STEM under most conditions. We examine why the STEM tree (also called GLASS or Maximum Tree) is less accurate on estimated gene trees by comparing estimated and true coalescence times, performing species tree inference using simulations, and analyzing a great ape data set keeping track of false positive and false negative rates for inferred clades. We find that although true coalescence times are more ancient than speciation times under the multispecies coalescent model, estimated coalescence times are often more recent than speciation times. This underestimation can lead to increased bias and lack of resolution with increased sampling (either alleles or loci) when gene trees are estimated with ML. The problem appears to be less severe using Bayesian gene-tree estimates.

  10. Species Tree Inference Using a Mixture Model.

    Science.gov (United States)

    Ullah, Ikram; Parviainen, Pekka; Lagergren, Jens

    2015-09-01

    Species tree reconstruction has been a subject of substantial research due to its central role across biology and medicine. A species tree is often reconstructed using a set of gene trees or by directly using sequence data. In either of these cases, one of the main confounding phenomena is the discordance between a species tree and a gene tree due to evolutionary events such as duplications and losses. Probabilistic methods can resolve the discordance by coestimating gene trees and the species tree but this approach poses a scalability problem for larger data sets. We present MixTreEM-DLRS: A two-phase approach for reconstructing a species tree in the presence of gene duplications and losses. In the first phase, MixTreEM, a novel structural expectation maximization algorithm based on a mixture model is used to reconstruct a set of candidate species trees, given sequence data for monocopy gene families from the genomes under study. In the second phase, PrIME-DLRS, a method based on the DLRS model (Åkerborg O, Sennblad B, Arvestad L, Lagergren J. 2009. Simultaneous Bayesian gene tree reconstruction and reconciliation analysis. Proc Natl Acad Sci U S A. 106(14):5714-5719), is used for selecting the best species tree. PrIME-DLRS can handle multicopy gene families since DLRS, apart from modeling sequence evolution, models gene duplication and loss using a gene evolution model (Arvestad L, Lagergren J, Sennblad B. 2009. The gene evolution model and computing its associated probabilities. J ACM. 56(2):1-44). We evaluate MixTreEM-DLRS using synthetic and biological data, and compare its performance with a recent genome-scale species tree reconstruction method PHYLDOG (Boussau B, Szöllősi GJ, Duret L, Gouy M, Tannier E, Daubin V. 2013. Genome-scale coestimation of species and gene trees. Genome Res. 23(2):323-330) as well as with a fast parsimony-based algorithm Duptree (Wehe A, Bansal MS, Burleigh JG, Eulenstein O. 2008. Duptree: a program for large-scale phylogenetic

  11. Diffusion processes and coalescent trees

    CERN Document Server

    Griffiths, Robert C

    2010-01-01

    We dedicate this paper to Sir John Kingman on his 70th Birthday. In modern mathematical population genetics the ancestral history of a population of genes back in time is described by John Kingman's coalescent tree. Classical and modern approaches model gene frequencies by diffusion processes. This paper, which is partly a review, discusses how coalescent processes are dual to diffusion processes in an analytic and probabilistic sense. Bochner (1954) and Gasper (1972) were interested in characterizations of processes with Beta stationary distributions and Jacobi polynomial eigenfunctions. We discuss the connection with Wright--Fisher diffusions and the characterization of these processes. Subordinated Wright--Fisher diffusions are of this type. An Inverse Gaussian subordinator is interesting and important in subordinated Wright--Fisher diffusions and is related to the Jacobi Poisson Kernel in orthogonal polynomial theory. A related time-subordinated forest of non-mutant edges in the Kingman coalescent is nove...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-31

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

  13. Language distance and tree reconstruction

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2008-08-01

    Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.

  14. Fruit load governs transpiration of olive trees

    NARCIS (Netherlands)

    Bustan, Amnon; Dag, Arnon; Yermiyahu, Uri; Erel, Ran; Presnov, Eugene; Agam, Nurit; Kool, Dilia; Iwema, Joost; Zipori, Isaac; Ben-Gal, Alon

    2016-01-01

    We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from tree

  15. A Note on Geodesically Bounded -Trees

    Directory of Open Access Journals (Sweden)

    Kirk WA

    2010-01-01

    Full Text Available It is proved that a complete geodesically bounded -tree is the closed convex hull of the set of its extreme points. It is also noted that if is a closed convex geodesically bounded subset of a complete -tree and if a nonexpansive mapping satisfies then has a fixed point. The latter result fails if is only continuous.

  16. Hyperdominance in the Amazonian tree flora

    NARCIS (Netherlands)

    Steege, ter H.; Pitman, C.A.; Sabatier, D.; Baraloto, C.; Salomão, R.P.; Guevara, J.E.; Phillips, O.L.; Castilho, C.V.; Magnusson, W.E.; Mollino, J.-F.; Stevenson Diaz, P.R.; Costa, F.; Emilio, T.; Levis, C.; Schietti, J.; Souza, P.; Alonso, A.; Dallmeier, F.; Duque Montoya, A.J.; Fernandez Piedade, M.T.; Maas, P.; Araujo-Murakami, A.; Arroyo, L.; Gribel, R.; Fine, P.V.A.; Peres, C.A.; Toledo, M.; Aymard, G.A.; Baker, T.R.; Cerón, C.; Engel, J.; Petronelli, P.; Henkel, T.W.; Stropp, J.; Zartman, C.E.; Daly, D.; Neill, D.; Silveira, M.; Ríos Paredes, M.; Chave, J.; de Andrade Lima Filho, D.; Hoffman, B.; Møller Jørgensen, P.; Fuentes, A.; Schöngart, J.; Cornejo Valverde, F.; Di Fiore, A.; Jimenez, E.M.; Peñuela Mora, M.C.; Phillips, J.F.; Rivas, G.; Andel, van T.R.; Zent, E.L.; Hildebrand, von P.; Malhi, Y.; Prieto, A.; Rudas, A.; Ruschell, A.; Silva, N.; Vos, V.; Zent, S.; Oliveira, A.A.; Wang, O.; Cano Schutz, A.; Gonzales, T.; Trindade Nascimento, M.; Ramirez-Angulo, H.; Sierra, R.; Tirado, M.; Umaña Medina, M.N.; Heijden, van der G.; Vela, C.I.A.; Vilanova Torre, E.; Young, K.R.; Vriesendorp, C.; Baider, C.; Balslev, H.; Ferreira, C.; Mesones, I.; Torres-Lezama, A.; Urrego Giraldo, L.E.; Zagt, R.; Alexiades, M.N.; Monteagudo, A.; Hernandez, L.; Huamantupa-Chuquimaco, I.; Millikes, W.; Palacios Cuenca, W.; Pauletto, D.; Valderrama Sandoval, E.; Valenzuela Gamarra, L.; Dexter, K.G.; Feeley, K.; Lopez-Gonzalez, G.; Núñez Vargas, P.; Silman, M.R.; Montero, J.C.; Feldpausch, T.R.; Honorio Coronado, E.N.; Killeen, T.J.; Mostacedo, B.; Vasquez, R.; Assis, R.L.; Terborgh, J.; Wittmann, F.; Andrade, A.; Laurance, W.F.; Laurance, S.G.W.; Marimon, B.S.; Marimon, B.-H. Jr.; Célia Guimarães Vieira, I.; Leão Amaral, I.; Brienen, R.; Castellanos, H.; Cárdenas López, D.; Duivenvoorden, J.F.; Mogollón, H.F.; Dionízia de Almeida Matos, F.; Dávila, N.; García-Villacorta, R.

    2013-01-01

    The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected i

  17. Algorithmic height compression of unordered trees.

    Science.gov (United States)

    Ben-Naoum, Farah; Godin, Christophe

    2016-01-21

    By nature, tree structures frequently present similarities between their sub-parts. Making use of this redundancy, different types of tree compression techniques have been designed in the literature to reduce the complexity of tree structures. A popular and efficient way to compress a tree consists of merging its isomorphic subtrees, which produces a directed acyclic graph (DAG) equivalent to the original tree. An important property of this method is that the compressed structure (i.e. the DAG) has the same height as the original tree, thus limiting partially the possibility of compression. In this paper we address the problem of further compressing this DAG in height. The difficulty is that compression must be carried out on substructures that are not exactly isomorphic as they are strictly nested within each-other. We thus introduced a notion of quasi-isomorphism between subtrees that makes it possible to define similar patterns along any given path in a tree. We then proposed an algorithm to detect these patterns and to merge them, thus leading to compressed structures corresponding to DAGs augmented with return edges. In this way, redundant information is removed from the original tree in both width and height, thus achieving minimal structural compression. The complete compression algorithm is then illustrated on the compression of various plant-like structures.

  18. Induced chemical defences in Colophospermum mopane trees

    NARCIS (Netherlands)

    Wessels, D.C.J.; Waal, van der C.; Boer, de W.F.

    2007-01-01

    A field experiment was conducted in which Mopane (Colophospermum mopane) trees were subjected to three different canopy treatments:felling of trees at a mean height of 0.7m above ground level, felling at a height of 2m, or pruning of selected branches. These treatments were intended to simulate wood

  19. Representing Boolean Functions by Decision Trees

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    A Boolean or discrete function can be represented by a decision tree. A compact form of decision tree named binary decision diagram or branching program is widely known in logic design [2, 40]. This representation is equivalent to other forms, and in some cases it is more compact than values table or even the formula [44]. Representing a function in the form of decision tree allows applying graph algorithms for various transformations [10]. Decision trees and branching programs are used for effective hardware [15] and software [5] implementation of functions. For the implementation to be effective, the function representation should have minimal time and space complexity. The average depth of decision tree characterizes the expected computing time, and the number of nodes in branching program characterizes the number of functional elements required for implementation. Often these two criteria are incompatible, i.e. there is no solution that is optimal on both time and space complexity. © Springer-Verlag Berlin Heidelberg 2011.

  20. Testing models of tree canopy structure

    Energy Technology Data Exchange (ETDEWEB)

    Martens, S.N. (Los Alamos National Laboratory, NM (United States))

    1994-06-01

    Models of tree canopy structure are difficult to test because of a lack of data which are suitability detailed. Previously, I have made three-dimensional reconstructions of individual trees from measured data. These reconstructions have been used to test assumptions about the dispersion of canopy elements in two- and three-dimensional space. Lacunarity analysis has also been used to describe the texture of the reconstructed canopies. Further tests regarding models of the nature of tree branching structures have been made. Results using probability distribution functions for branching measured from real trees show that branching in Juglans is not Markovian. Specific constraints or rules are necessary to achieve simulations of branching structure which are faithful to the originally measured trees.

  1. Timing-Driven-Testable Convergent Tree Adders

    Directory of Open Access Journals (Sweden)

    Johnnie A. Huang

    2002-01-01

    Full Text Available Carry lookahead adders have been, over the years, implemented in complex arithmetic units due to their regular structure which leads to efficient VLSI implementation for fast adders. In this paper, timing-driven testability synthesis is first performed on a tree adder. It is shown that the structure of the tree adder provides for a high fanout with an imbalanced tree structure, which likely contributes to a racing effect and increases the delay of the circuit. The timing optimization is then realized by reducing the maximum fanout of the adder and by balancing the tree circuit. For a 56-b testable tree adder, the optimization produces a 6.37%increase in speed of the critical path while only contributing a 2.16% area overhead. The full testability of the circuit is achieved in the optimized adder design.

  2. Tree mineral nutrition is deteriorating in Europe

    DEFF Research Database (Denmark)

    Jonard, Mathieu; Fürst, Alfred; Verstraeten, Arne;

    2015-01-01

    The response of forest ecosystems to increased atmospheric CO2 is constrained by nutrient availability. It is thus crucial to account for nutrient limitation when studying the forest response to climate change. The objectives of this study were to describe the nutritional status of the main...... European tree species, to identify growth-limiting nutrients and to assess changes in tree nutrition during the past two decades. We analysed the foliar nutrition data collected during 1992–2009 on the intensive forest monitoring plots of the ICP Forests programme. Of the 22 significant temporal trends...... to higher nutrient demand by trees. As the soil nutrient supply was not always sufficient to meet the demands of faster growing trees, this could partly explain the deterioration of tree mineral nutrition. The results suggest that when evaluating forest carbon storage capacity and when planning to reduce CO...

  3. Letter: TreeAdder: a tool to assist the optimal positioning of a new leaf into an existing phylogenetic tree

    OpenAIRE

    Gatherer, D.

    2007-01-01

    TreeAdder is a computer application that adds a leaf in all possible positions on a phylogenetic tree. The resulting set of trees represent a dataset appropriate for maximum likelihood calculation of the optimal tree. TreeAdder therefore provides a utility for what was previously a tedious and error-prone process.

  4. Cache-Oblivious Search Trees via Binary Trees of Small Height

    DEFF Research Database (Denmark)

    Brodal, G.S.; Fagerberg, R.; Jacob, R.

    2002-01-01

    We propose a version of cache oblivious search trees which is simpler than the previous proposal of Bender, Demaine and Farach-Colton and has the same complexity bounds. In particular, our data structure avoids the use of weight balanced B-trees, and can be implemented as just a single array......, and range queries in worst case O(logB n + k/B) memory transfers, where k is the size of the output.The basic idea of our data structure is to maintain a dynamic binary tree of height log n+O(1) using existing methods, embed this tree in a static binary tree, which in turn is embedded in an array in a cache...... oblivious fashion, using the van Emde Boas layout of Prokop.We also investigate the practicality of cache obliviousness in the area of search trees, by providing an empirical comparison of different methods for laying out a search tree in memory....

  5. Christmas: A $157 Million Hangover

    Institute of Scientific and Technical Information of China (English)

    庄秀琴

    2002-01-01

    本文出语惊人,圣诞节是怎样一个节日?本文下了这样的定义:Chrhtmas is one of Britain’s most unhealthy times of the year.乍见此句,觉得不可理解,读完全文,便觉得有理。笔者很自然地想到国人的春节。我们是否能说:Spring Festival is one of China’s most unhealthy times of the year.

  6. An efficient and extensible approach for compressing phylogenetic trees

    KAUST Repository

    Matthews, Suzanne J

    2011-01-01

    Background: Biologists require new algorithms to efficiently compress and store their large collections of phylogenetic trees. Our previous work showed that TreeZip is a promising approach for compressing phylogenetic trees. In this paper, we extend our TreeZip algorithm by handling trees with weighted branches. Furthermore, by using the compressed TreeZip file as input, we have designed an extensible decompressor that can extract subcollections of trees, compute majority and strict consensus trees, and merge tree collections using set operations such as union, intersection, and set difference.Results: On unweighted phylogenetic trees, TreeZip is able to compress Newick files in excess of 98%. On weighted phylogenetic trees, TreeZip is able to compress a Newick file by at least 73%. TreeZip can be combined with 7zip with little overhead, allowing space savings in excess of 99% (unweighted) and 92%(weighted). Unlike TreeZip, 7zip is not immune to branch rotations, and performs worse as the level of variability in the Newick string representation increases. Finally, since the TreeZip compressed text (TRZ) file contains all the semantic information in a collection of trees, we can easily filter and decompress a subset of trees of interest (such as the set of unique trees), or build the resulting consensus tree in a matter of seconds. We also show the ease of which set operations can be performed on TRZ files, at speeds quicker than those performed on Newick or 7zip compressed Newick files, and without loss of space savings.Conclusions: TreeZip is an efficient approach for compressing large collections of phylogenetic trees. The semantic and compact nature of the TRZ file allow it to be operated upon directly and quickly, without a need to decompress the original Newick file. We believe that TreeZip will be vital for compressing and archiving trees in the biological community. © 2011 Matthews and Williams; licensee BioMed Central Ltd.

  7. Tree decline and the future of Australian farmland biodiversity

    OpenAIRE

    Fischer, Joern; Zerger, Andre; Gibbons, Phil; Stott, Jenny; Law, Bradley S.

    2010-01-01

    Farmland biodiversity is greatly enhanced by the presence of trees. However, farmland trees are declining worldwide, including in North America, Central America, and parts of southern Europe. We show that tree decline and its likely consequences are particularly severe in Australia's temperate agricultural zone, which is a threatened ecoregion. Using field data on trees, remotely sensed imagery, and a demographic model for trees, we predict that by 2100, the number of trees on an average farm...

  8. Reconstruction Conjecture for Graphs Isomorphic to Cube of a Tree

    OpenAIRE

    Gupta, S.K.; Khandelwal, Akash

    2012-01-01

    This paper proves the reconstruction conjecture for graphs which are isomorphic to the cube of a tree. The proof uses the reconstructibility of trees from their peripheral vertex deleted subgraphs. The main result follows from (i) characterization of the cube of a tree (ii) recognizability of the cube of a tree (iii) uniqueness of tree as a cube root of a graph G, except when G is a complete graph (iv) reconstructibility of trees from their peripheral vertex deleted subgraphs.

  9. Sussing Merger Trees: Stability and Convergence

    CERN Document Server

    Wang, Yang; Knebe, Alexander; Schneider, Aurel; Srisawat, Chaichalit; Tweed, Dylan; Jung, Intae; Han, Jiaxin; Helly, John; Onions, Julian; Elahi, Pascal J; Thomas, Peter A; Behroozi, Peter; Yi, Sukyoung K; Rodriguez-Gomez, Vicente; Mao, Yao-Yuan; Jing, Yipeng; Lin, Weipeng

    2016-01-01

    Merger trees are routinely used to follow the growth and merging history of dark matter haloes and subhaloes in simulations of cosmic structure formation. Srisawat et al. (2013) compared a wide range of merger-tree-building codes. Here we test the influence of output strategies and mass resolution on tree-building. We find that, somewhat surprisingly, building the tree from more snapshots does not generally produce more complete trees; instead, it tends to short- en them. Significant improvements are seen for patching schemes which attempt to bridge over occasional dropouts in the underlying halo catalogues or schemes which combine the halo-finding and tree-building steps seamlessly. The adopted output strategy does not affec- t the average number of branches (bushiness) of the resultant merger trees. However, mass resolution has an influence on both main branch length and the bushiness. As the resolution increases, a halo with the same mass can be traced back further in time and will encounter more small pro...

  10. A modified TreePM code

    Institute of Scientific and Technical Information of China (English)

    Nishikanta Khandai; J. S. Bagla

    2009-01-01

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

  11. Urban tree effects on soil organic carbon.

    Directory of Open Access Journals (Sweden)

    Jill L Edmondson

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

  12. Urban tree effects on soil organic carbon.

    Science.gov (United States)

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

    2014-01-01

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

  13. Reconciliation of Gene and Species Trees

    Directory of Open Access Journals (Sweden)

    L. Y. Rusin

    2014-01-01

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

  14. Wind profiles in and over trees

    Institute of Scientific and Technical Information of China (English)

    ZHUJiao-jun; LIXiu-fen; GondaYutaka; MatsuzakiTakeshi

    2004-01-01

    One of the most important and frequently studied variable in forests and the most basic element in governing transport processes of airflow is wind speed. The study of wind profile, defined as the change of wind velocity with height, and wind velocity are important because of tree physiological and developmental responses. Generally, wind profiles above the ground or at a canopy surface follow classical logarithm law, but wind profiles in a single tree and in a forest stand are not logarithmic. This paper summarizes the results of wind profile studies within a single tree, in a forest stand, above the forest canopy and in a forest area from recent research in a coastal pine forest. The results demonstrate that: 1) wind profiles with in a single conifer tree crown showed an exponential function with height, 2) wind profiles in forest stands were able to be expressed by attenuation coefficient of wind, 3) wind profiles over a forest canopy could be determined using profile parameters (friction velocity, roughness length and displacement), and 4) for a forest area, the extreme wind speed could be predicted reasonably using the methods developed for the design of buildings. More research will be required to demonstrate: 1) relationships between wind profiles and tree or stand characteristics, 2) the simple methods for predicting wind profile parameters, and 3) the applications of wind profile in studies of tree physiology, forest ecology and management, and the detail ecological effects of wind on tree growth.

  15. Detecting Coppice Legacies from Tree Growth.

    Science.gov (United States)

    Müllerová, Jana; Pejcha, Vít; Altman, Jan; Plener, Tomáš; Dörner, Petr; Doležal, Jiří

    2016-01-01

    In coppice-with-standards, once a common type of management in Central European lowland forests, selected trees (standards) were left to grow mature among the regularly harvested coppice stools to obtain construction wood. After the underwood was harvested, the forest canopy opened rapidly, giving standard trees an opportunity to benefit from reduced competition. Although this silvicultural system virtually disappeared after WWII, historical management cycles can still be traced in the tree-rings of remaining standards. Our research aims at answering the question whether tree-ring series of standard trees can be used to reconstruct past management practices. The study was carried out on 117 oak standard trees from five sites situated in formerly coppiced calcareous oak-hornbeam and acidophilous oak forests in the Bohemian Karst Protected Landscape Area, Czech Republic. The evaluation was based on the analysis of growth releases representing the response of the standards to coppicing events, and comparison to the archival records of coppice events. Our results showed that coppicing events can be successfully detected by tree-ring analysis, although there are some limitations. Altogether 241 releases were identified (49% of major releases). Large number of releases could be related to historical records, with the major ones giving better results. The overall probability of correct detection (positive predictive power) was 58%, ranging from 50 to 67%, probability for major releases was 78%, ranging from 63 to 100% for different sites. The ability of individual trees to mirror past coppice events was significantly affected by competition from neighboring trees (their number and the sum of distance-weighted basal areas). A dendro-ecological approach to the study of forest management history can serve as an input for current attempts of coppice reintroduction and for conservation purposes.

  16. Perception of Shea Nut Tree as an Economic Tree among Farmers in Oyo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Rasheed Gbolagade Adeola

    2012-06-01

    Full Text Available The importance of shea tree to the people of south-westernNigeria cannot be over emphasized considering both theeconomic and environmental uses of the tree. However, effortshave not been made to propagate its production by the farmersas the shea tree still grows in the wild state. It would beworthwhile to investigate farmers’ perception of shea nut tree asan economic tree and their attitudes toward the conservationmeasures needed to prevent its extinction. Multi-stage samplingtechnique was used to select 160 farmers for the study. Astructured interview schedule was used to collect data from therespondents. Descriptive statistics of means and percentageswere used to describe the data while correlation coefficientswere employed to determine the relationships that exist betweenfarmers’ perception and their socio- economics characteristics.A larger percentage of the farmers claimed the awareness of thepotential products of shea nut trees. Majority (90.6% of the respondentsperceived shea tree as an economic tree and indicatedthat it provides income for women and children that gather thefruits. Most of the farmers had favourable attitude toward shea nuttree as an economic tree. Land ownership status (r = 0.536, age(r = 0.875, education (r = 0.725, farming experience (r = 0.508,household size (r = -0.817 and farm size (r = -0.673 hadsignificant influence on the perception of farmers. The studytherefore recommends that the extension agencies should playsignificant role in educating the farmers on the importance ofconserving the trees to sustain its economic benefits.

  17. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    Science.gov (United States)

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

  18. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    Science.gov (United States)

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment. PMID:26594707

  19. Trees in Towns: Factors Affecting the Distribution of Trees in High Density Residential Areas of Greater Manchester

    OpenAIRE

    Hall, Justine Michelle

    2010-01-01

    The distribution of trees across urban areas of the UK has been shown to be uneven, with lower density residential areas containing many more trees and much higher tree cover than areas of higher density housing. However, in Greater Manchester, tree number within high density housing areas also varies substantially. This thesis sought to explore the reasons for this variation in tree cover, whether tree cover should be increased and if so, how. The research investigated a potential cause for ...

  20. Behavior Trees for Evolutionary Robotics.

    Science.gov (United States)

    Scheper, Kirk Y W; Tijmons, Sjoerd; de Visser, Cornelis C; de Croon, Guido C H E

    2016-01-01

    Evolutionary Robotics allows robots with limited sensors and processing to tackle complex tasks by means of sensory-motor coordination. In this article we show the first application of the Behavior Tree framework on a real robotic platform using the evolutionary robotics methodology. This framework is used to improve the intelligibility of the emergent robotic behavior over that of the traditional neural network formulation. As a result, the behavior is easier to comprehend and manually adapt when crossing the reality gap from simulation to reality. This functionality is shown by performing real-world flight tests with the 20-g DelFly Explorer flapping wing micro air vehicle equipped with a 4-g onboard stereo vision system. The experiments show that the DelFly can fully autonomously search for and fly through a window with only its onboard sensors and processing. The success rate of the optimized behavior in simulation is 88%, and the corresponding real-world performance is 54% after user adaptation. Although this leaves room for improvement, it is higher than the 46% success rate from a tuned user-defined controller. PMID:26606468

  1. Behavior Trees for Evolutionary Robotics.

    Science.gov (United States)

    Scheper, Kirk Y W; Tijmons, Sjoerd; de Visser, Cornelis C; de Croon, Guido C H E

    2016-01-01

    Evolutionary Robotics allows robots with limited sensors and processing to tackle complex tasks by means of sensory-motor coordination. In this article we show the first application of the Behavior Tree framework on a real robotic platform using the evolutionary robotics methodology. This framework is used to improve the intelligibility of the emergent robotic behavior over that of the traditional neural network formulation. As a result, the behavior is easier to comprehend and manually adapt when crossing the reality gap from simulation to reality. This functionality is shown by performing real-world flight tests with the 20-g DelFly Explorer flapping wing micro air vehicle equipped with a 4-g onboard stereo vision system. The experiments show that the DelFly can fully autonomously search for and fly through a window with only its onboard sensors and processing. The success rate of the optimized behavior in simulation is 88%, and the corresponding real-world performance is 54% after user adaptation. Although this leaves room for improvement, it is higher than the 46% success rate from a tuned user-defined controller.

  2. GIS Applications in Urban Tree Inventory

    OpenAIRE

    Otey, Jennifer K.

    2007-01-01

    This project evaluates and demonstrates some applications of a GIS-based urban tree inventory. This was done by (1) collecting and analyzing data for Tinker Air Force Base (AFB), and (2) collecting and evaluating data for the Virginia Tech campus tree inventory. The urban tree inventory at Tinker AFB was estimated using remote sensing techniques that included the use of the eCognition 3.0 software. Inventory data was collected using a handheld computer and transferred to a desktop for data ba...

  3. Bounds of Spectral Radii of Weighted Trees

    Institute of Scientific and Technical Information of China (English)

    杨华中; 胡冠章; 洪渊

    2003-01-01

    Graphs for the design of networks or electronic circuits are usually weighted and the spectrum of weighted graphs are often analyzed to solve problems. This paper discusses the spectrum and the spectral radii of trees with edge weights. We derive expressions for the spectrum and the spectral radius of a weighted star, together with the boundary limits of the spectral radii for weighted paths and weighted trees. The analysis uses the theory of nonnegative matrices and applies the "moving edge" technique. Some simple examples of weighted paths and trees are presented to explain the results. Then, we propose some open problems in this area.

  4. Chemical trees minimizing energy and Hosoya index

    OpenAIRE

    Heuberger, Clemens; Wagner, Stephan G.

    2008-01-01

    The energy of a molecular graph is a popular parameter that is defined as the sum of the absolute values of a graph's eigenvalues. It is well known that the energy is related to the matching polynomial and thus also to the Hosoya index via a certain Coulson integral. Trees minimizing the energy under various additional conditions have been determined in the past, e.g., trees with a given diameter or trees with a perfect matching. However, it is quite a natural problem to minimize the energy o...

  5. Algorithms for optimal dyadic decision trees

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  6. The tree length of an evolving coalescent

    CERN Document Server

    Pfaffelhuber, Peter; Weisshaupt, Heinz

    2009-01-01

    A well-established model for the genealogy of a large population in equilibrium is Kingman's coalescent. For the population together with its genealogy evolving in time, this gives rise to a time-stationary tree-valued process. We study the sum of the branch lengths, briefly denoted as tree length, and prove that the (suitably compensated) sequence of tree length processes converges, as the population size tends to infinity, to a limit process with cadlag paths, infinite infinitesimal variance, and a Gumbel distribution as its equilibrium.

  7. Public Reactions to New Street Tree Planting

    OpenAIRE

    Ruth A. Rae; Gabriel Simon; Jessie Braden

    2010-01-01

    MillionTreesNYC, which has the goal of planting one million trees in New York City by 2017, is intended to make New York City a greener, more sustainable city and is part of the Mayor’s comprehensive long term strategic plan, PlaNYC. Through planting a tree at every suitable sidewalk location in the city, the City of New York is transforming blocks and communities, and providing a variety of environmental, social and aesthetic benefits. This article examines the large scale municipal planting...

  8. Chopper: Efficient Algorithm for Tree Mining

    Institute of Scientific and Technical Information of China (English)

    ChenWang; Ming-ShengHong; WeiWang; Bai-LeShi

    2004-01-01

    With the development of Internet, frequent pattern mining has been extended to more complex patterns like tree mining and graph mining. Such applications arise in complex domains like bioinformatics, web mining, etc. In this paper, we present a novel algorithm, named Chopper, to discover frequent subtrees from ordered labeled trees. An extensive performance study shows that the newly developed algorithm outperforms TreeMinerV, one of the fastest methods proposed previously, in mining large databases. At the end of this paper, the potential improvement of Chopper is mentioned.

  9. Chopper:Efficient Algorithm for Tree Mining

    Institute of Scientific and Technical Information of China (English)

    Chen Wang; Ming-Sheng Hong; Wei Wang; Bai-Le Shi

    2004-01-01

    With the development of Internet, frequent pattern mining has been extended to more complex patterns like tree mining and graph mining. Such applications arise in complex domains like bioinformatics, web mining, etc. In this paper, we present a novel algorithm, named Chopper, to discover frequent subtrees from ordered labeled trees. An extensive performance study shows that the newly developed algorithm outperforms TreeMinerV, one of the fastest methods proposed previously, in mining large databases. At the end of this paper,the potential improvement of Chopper is mentioned.

  10. A tree of tree frogs around the Black Sea.

    Science.gov (United States)

    Irwin, Darren E

    2016-09-01

    Speciation, the process by which one species evolves into two or more, is a major focus of ongoing debate, particularly regarding the geographic context in which it occurs. Geographic models of speciation tend to fall into discrete categories, typically referred to as allopatric, parapatric and sympatric speciation, according to whether two groups evolve reproductive isolation while geographically isolated, differentiated but connected by gene flow, or completely co-occurring. Yet molecular studies indicate that full development of reproductive isolation can take very long compared with the timescale at which climatic oscillations occur, such that the geographic context of differentiating forms might change often during the long process to full species. Studies of genetic relationships across the ranges of organisms with low-dispersal distances have the potential to reveal these complex histories. In a particularly elegant example in this issue, Dufresnes et al. () use genetic variation and ecological niche modelling to show that a ring of populations of the eastern tree frog (Hyla orientalis) surrounding the Black Sea had a complex history of geographic differentiation. Alternating phases of geographic fragmentation and phases of gene flow between neighbouring populations have produced a pattern of gradual genetic change connecting the western, southern and eastern sides of the ring, with the northwestern and northeastern forms being most differentiated. In the north, a population in Crimea appears to have been produced through mixture of the two extreme forms. The overall genetic relationships are reminiscent of those found in ring species, which have been used as prime demonstrations of the process of speciation. The difference, however, is that the terminal forms appear to have mixed rather than be reproductively isolated, although more research is needed to infer whether there might be some reproductive isolation on the northern side of the ring. PMID

  11. 77 FR 61024 - Notice of Public Meeting and Request for Comments

    Science.gov (United States)

    2012-10-05

    ..., Interior. ACTION: Notice/Request for public meeting and public comments--The National Christmas Tree... suggestions on the planning of the 2012 National Christmas Tree Lighting and the subsequent 26-day event. The... traditional American symbols of Christmas. DATES: The meeting will be held on Friday, November 2,...

  12. 78 FR 66762 - Notice of Public Meeting and Request for Comments

    Science.gov (United States)

    2013-11-06

    ... Christmas Tree Lighting and the subsequent 26- day event. SUMMARY: The National Park Service is seeking public comments and suggestions on the planning of the 2013 National Christmas Tree Lighting and the... with the display of the traditional American symbols of Christmas. DATES: The meeting will be held...

  13. FB-Tree: A B+-Tree for Flash-Based SSDs

    DEFF Research Database (Denmark)

    Jørgensen, Martin V.; Rasmussen, René B.; Saltenis, Simonas;

    2011-01-01

    the FB-tree: a combination of an adapted B+-tree, a storage manager, and a buffer manager, all optimized for modern SSDs. Together the techniques enable writing to SSDs in relatively large blocks, thus achieving greater overall throughput. This is achieved by the out-of-place writing, whereby every time...... a modified index node is written, it is written to a new address, clustered with some other nodes that are written together. While this constantly frees index nodes, the FB-tree does not introduce any garbage-collection overhead, instead relying on naturally occurring free-space segments of sufficient size....... As a consequence, the FB-tree outperforms a regular B+-tree in all scenarios tested. For instance, the throughput of a random workload of 75% updates increases by a factor of three using only two times the space of the B+-tree....

  14. Controls on tree water uptake and information storage in tree rings

    Science.gov (United States)

    Blume, Theresa; Simard, Sonia; Heidbüchel, Ingo; Güntner, Andreas; Heinrich, Ingo

    2016-04-01

    Controls on tree water uptake are investigated in various forest stands in the northeastern German lowlands by a multi-method approach. This approach combines sapflow and dendrometer measurements as well as tree-ring analyses with soil moisture derived root water uptake rates. The latter method has the advantage that it provides depth distributions of root water uptake and thus additional information allowing for a more detailed analysis of the relationship between water availability and water uptake. High resolution climatic data makes it possible to investigate the site specific interplay between atmospheric demand and water availability on the one hand and tree response and adaptation on the other hand. The comparison of spatio-temporal patterns of these responses with concurrent tree growth as well as tree-ring analyses enables a first matching of actual and "archived" patterns and thus an estimate of how much of this information is stored in tree rings.

  15. The Fate of Carbon in Deciduous Trees

    Energy Technology Data Exchange (ETDEWEB)

    Keel, S.; Koerner, Ch. [University of Basel (Switzerland); Siegwolf, R.T.W.

    2004-03-01

    To study the allocation of recently fixed carbon (photo assimilates) in mature deciduous trees, we apply pulse labelling experiments by enclosing small branches in branch bags with highly {sup 13}C enriched CO{sub 2} (author)

  16. Image Segmentation Using Hierarchical Merge Tree

    Science.gov (United States)

    Liu, Ting; Seyedhosseini, Mojtaba; Tasdizen, Tolga

    2016-10-01

    This paper investigates one of the most fundamental computer vision problems: image segmentation. We propose a supervised hierarchical approach to object-independent image segmentation. Starting with over-segmenting superpixels, we use a tree structure to represent the hierarchy of region merging, by which we reduce the problem of segmenting image regions to finding a set of label assignment to tree nodes. We formulate the tree structure as a constrained conditional model to associate region merging with likelihoods predicted using an ensemble boundary classifier. Final segmentations can then be inferred by finding globally optimal solutions to the model efficiently. We also present an iterative training and testing algorithm that generates various tree structures and combines them to emphasize accurate boundaries by segmentation accumulation. Experiment results and comparisons with other very recent methods on six public data sets demonstrate that our approach achieves the state-of-the-art region accuracy and is very competitive in image segmentation without semantic priors.

  17. Big Fish and Prized Trees Gain Protection

    Institute of Scientific and Technical Information of China (English)

    Fred Pearce; 吴敏

    2004-01-01

    @@ Decisions made at a key conservation① meeting are good news for big and quirky② fish and commercially prized trees. Several species will enjoy extra protection against trade following rulings made at the Convention on International Trade in Endangered Species (CITES).

  18. Tree wavelet approximations with applications

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    [1]Baraniuk, R. G., DeVore, R. A., Kyriazis, G., Yu, X. M., Near best tree approximation, Adv. Comput. Math.,2002, 16: 357-373.[2]Cohen, A., Dahmen, W., Daubechies, I., DeVore, R., Tree approximation and optimal encoding, Appl. Comput.Harmonic Anal., 2001, 11: 192-226.[3]Dahmen, W., Schneider, R., Xu, Y., Nonlinear functionals of wavelet expansions-adaptive reconstruction and fast evaluation, Numer. Math., 2000, 86: 49-101.[4]DeVore, R. A., Nonlinear approximation, Acta Numer., 1998, 7: 51-150.[5]Davis, G., Mallat, S., Avellaneda, M., Adaptive greedy approximations, Const. Approx., 1997, 13: 57-98.[6]DeVore, R. A., Temlyakov, V. N., Some remarks on greedy algorithms, Adv. Comput. Math., 1996, 5: 173-187.[7]Kashin, B. S., Temlyakov, V. N., Best m-term approximations and the entropy of sets in the space L1, Mat.Zametki (in Russian), 1994, 56: 57-86.[8]Temlyakov, V. N., The best m-term approximation and greedy algorithms, Adv. Comput. Math., 1998, 8:249-265.[9]Temlyakov, V. N., Greedy algorithm and m-term trigonometric approximation, Constr. Approx., 1998, 14:569-587.[10]Hutchinson, J. E., Fractals and self similarity, Indiana. Univ. Math. J., 1981, 30: 713-747.[11]Binev, P., Dahmen, W., DeVore, R. A., Petruchev, P., Approximation classes for adaptive methods, Serdica Math.J., 2002, 28: 1001-1026.[12]Gilbarg, D., Trudinger, N. S., Elliptic Partial Differential Equations of Second Order, Berlin: Springer-Verlag,1983.[13]Ciarlet, P. G., The Finite Element Method for Elliptic Problems, New York: North Holland, 1978.[14]Birman, M. S., Solomiak, M. Z., Piecewise polynomial approximation of functions of the class Wαp, Math. Sb.,1967, 73: 295-317.[15]DeVore, R. A., Lorentz, G. G., Constructive Approximation, New York: Springer-Verlag, 1993.[16]DeVore, R. A., Popov, V., Interpolation of Besov spaces, Trans. Amer. Math. Soc., 1988, 305: 397-414.[17]Devore, R., Jawerth, B., Popov, V., Compression of wavelet decompositions, Amer. J. Math., 1992, 114: 737-785.[18]Storozhenko, E

  19. Propagation Mechanism of Electrical Tree in XLPE Cable Insulation by investigating a Double Electrical Tree Structure

    OpenAIRE

    Zheng, Xiaoquan; Chen, George

    2008-01-01

    This paper presents our experiments and analysis of the electrical tree growing characteristics. The relationship between electrical tree propagation and the material morphology in XLPE cable insulation has been studied by researching the structure and growth characteristics of a double structure electrical tree. It has been found that, due to the influence of uneven congregating state, difference in crystalline structure, and the existence of residual stress in semi-crystalline polymer, five...

  20. Tree and tree-like species of Mexico: Asteraceae, Leguminosae, and Rubiaceae

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.; Mario Sousa; Helga Ochoterena

    2013-01-01

    Trees or tree-like plants are defined here broadly as perennial, self-supporting plants with a total height of at least 5 m (without ascending leaves or inflorescences), and with one or several erect stems with a diameter of at least 10 cm. We continue our compilation of an updated list of all native Mexican tree species with the dicotyledonous families Asteraceae (36 species, 39% endemic), Leguminosae with its 3 subfamilies (449 species, 41% endemic), and Rubiaceae (134 species, 24% endemic)...

  1. TPM: Tree-Particle-Mesh code

    Science.gov (United States)

    Bode, Paul

    2013-05-01

    TPM carries out collisionless (dark matter) cosmological N-body simulations, evolving a system of N particles as they move under their mutual gravitational interaction. It combines aspects of both Tree and Particle-Mesh algorithms. After the global PM forces are calculated, spatially distinct regions above a given density contrast are located; the tree code calculates the gravitational interactions inside these denser objects at higher spatial and temporal resolution. The code is parallel and uses MPI for message passing.

  2. Pocket Checklists of Indonesian timber trees

    OpenAIRE

    Prawira, Soewanda A.; Tantra, I.G.M.; Whitmore, T.C.

    1984-01-01

    Indonesia as yet does not have a comprehensive account of the forest trees which reach timber size (35 cm dbh = 14 inch or 105 cm gbh = 42 inch). A project has been started in August 1983 by the Botany Section of the Forest Research Institute in Bogor, Indonesia, to prepare pocket checklists of the timber trees of all regions of the country. These lists will include forest-based descriptions, keys and line drawings.

  3. Computation of Greeks using Binomial Tree

    OpenAIRE

    Yoshifumi Muroi; Shintaro Suda

    2014-01-01

    This paper proposes a new efficient algorithm for the computation of Greeks for options using the binomial tree. We also show that Greeks for European options introduced in this article are asymptotically equivalent to the discrete version of Malliavin Greeks. This fact enables us to show that our Greeks converge to Malliavin Greeks in the continuous time model. The computation algorithms of Greeks for American options using the binomial tree is also given in this article. There are three adv...

  4. The International Small Group Tree Planting Program

    OpenAIRE

    Institute for Environmental Innovation (I4EI); Clean Air Action Corporation (CAAC)

    2007-01-01

    The International Small Group Tree Planting program (TIST) empowers small groups of subsistence farmers in countries such as Tanzania, Kenya, Uganda and India to reverse the devastating effects of deforestation, drought, and famine. Since 1999, TIST participants have been identifying local sustainable development goals that include tree planting and sustainable agriculture. TIST creates a communication and administrative structure that also addresses health (including HIV/AIDS), education, an...

  5. Arginine, scurvy and Cartier's "tree of life"

    OpenAIRE

    Durzan Don J

    2009-01-01

    Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compoun...

  6. LIMITING BEHAVIOR OF UNIFORM RECURSIVE TREES

    Institute of Scientific and Technical Information of China (English)

    Su Chun; Feng Qunqiang; Liu Jie

    2007-01-01

    The authors consider the limiting behavior of various branches in a uniform recursive tree with size growing to infinity. The limiting distribution of ζn,m, the number of branches with size m in a uniform recursive tree of order n, converges weakly to a Poisson distribution with parameter 1/m with convergence of all moments. The size of any large branch tends to infinity almost surely.

  7. Speeding Up Neighbour-Joining Tree Construction

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas;

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... the search for the next pair of nodes to join, but di#er in the information stored in quad-tree nodes, the way the search is performed, and in the way the quad-tree is updated after a join. We empirically evaluate the performance of the heuristics on distance matrices obtained from the Pfam collection...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for medium sized...

  8. Comparing and Aggregating Partially Resolved Trees

    CERN Document Server

    Bansal, Mukul S; Fernández-Baca, David

    2009-01-01

    We define, analyze, and give efficient algorithms for two kinds of distance measures for rooted and unrooted phylogenies. For rooted trees, our measures are based on the topologies the input trees induce on triplets; that is, on three-element subsets of the set of species. For unrooted trees, the measures are based on quartets (four-element subsets). Triplet and quartet-based distances provide a robust and fine-grained measure of the similarities between trees. The distinguishing feature of our distance measures relative to traditional quartet and triplet distances is their ability to deal cleanly with the presence of unresolved nodes, also called polytomies. For rooted trees, these are nodes with more than two children; for unrooted trees, they are nodes of degree greater than three. Our first class of measures are parametric distances, where there is a parameter that weighs the difference between an unresolved triplet/quartet topology and a resolved one. Our second class of measures are based on Hausdorff d...

  9. A global history of Australian trees.

    Science.gov (United States)

    Bennett, Brett M

    2011-01-01

    Scholars studying the globalization of Australian trees have previously emphasized the rapid natural propagation of Australian trees outside of their native habitats, believing their success to be a reversal of "ecological imperialism" from the "new world" to the "old world." This article argues that the expansion of Australian trees should not be viewed as a biological phenomenon, but as the result of a long-term attempt by powerful states and state-sponsored scientists to select and breed Australian species that could grow in a variety of climates and ecological conditions. Five non-biological factors largely determined the success of these attempts to grow Australian trees: the abundance or paucity of natural forests, state power, the amount of scientific research directed to planting Australian trees, the cost of labor, and the ability to utilize hardwood timbers and bark. This paper compares the use of Australian trees in Australia, India, and South Africa to demonstrate that biology was not the determining factor in the long-term success of many Australian genera and species. PMID:20665086

  10. Genomics-assisted breeding in fruit trees.

    Science.gov (United States)

    Iwata, Hiroyoshi; Minamikawa, Mai F; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding.

  11. Transforming phylogenetic networks: Moving beyond tree space.

    Science.gov (United States)

    Huber, Katharina T; Moulton, Vincent; Wu, Taoyang

    2016-09-01

    Phylogenetic networks are a generalization of phylogenetic trees that are used to represent reticulate evolution. Unrooted phylogenetic networks form a special class of such networks, which naturally generalize unrooted phylogenetic trees. In this paper we define two operations on unrooted phylogenetic networks, one of which is a generalization of the well-known nearest-neighbor interchange (NNI) operation on phylogenetic trees. We show that any unrooted phylogenetic network can be transformed into any other such network using only these operations. This generalizes the well-known fact that any phylogenetic tree can be transformed into any other such tree using only NNI operations. It also allows us to define a generalization of tree space and to define some new metrics on unrooted phylogenetic networks. To prove our main results, we employ some fascinating new connections between phylogenetic networks and cubic graphs that we have recently discovered. Our results should be useful in developing new strategies to search for optimal phylogenetic networks, a topic that has recently generated some interest in the literature, as well as for providing new ways to compare networks. PMID:27224010

  12. Horton Law in Self-Similar Trees

    Science.gov (United States)

    Kovchegov, Yevgeniy; Zaliapin, Ilya

    2016-04-01

    Self-similarity of random trees is related to the operation of pruning. Pruning ℛ cuts the leaves and their parental edges and removes the resulting chains of degree-two nodes from a finite tree. A Horton-Strahler order of a vertex v and its parental edge is defined as the minimal number of prunings necessary to eliminate the subtree rooted at v. A branch is a group of neighboring vertices and edges of the same order. The Horton numbers 𝒩k[K] and 𝒩ij[K] are defined as the expected number of branches of order k, and the expected number of order-i branches that merged order-j branches, j > i, respectively, in a finite tree of order K. The Tokunaga coefficients are defined as Tij[K] = 𝒩ij[K]/𝒩j[K]. The pruning decreases the orders of tree vertices by unity. A rooted full binary tree is said to be mean-self-similar if its Tokunaga coefficients are invariant with respect to pruning: Tk := Ti,i+k[K]. We show that for self-similar trees, the condition limsupk→∞Tk1/k 0 and every k ≥ 1. This work is a step toward providing rigorous foundations for the Horton law that, being omnipresent in natural branching systems, has escaped so far a formal explanation.

  13. Tree structure compression with RePair

    CERN Document Server

    Lohrey, Markus; Mennicke, Roy

    2010-01-01

    In this work we introduce a new linear time compression algorithm, called "Re-pair for Trees", which compresses ranked ordered trees using linear straight-line context-free tree grammars. Such grammars generalize straight-line context-free string grammars and allow basic tree operations, like traversal along edges, to be executed without prior decompression. Our algorithm can be considered as a generalization of the "Re-pair" algorithm developed by N. Jesper Larsson and Alistair Moffat in 2000. The latter algorithm is a dictionary-based compression algorithm for strings. We also introduce a succinct coding which is specialized in further compressing the grammars generated by our algorithm. This is accomplished without loosing the ability do directly execute queries on this compressed representation of the input tree. Finally, we compare the grammars and output files generated by a prototype of the Re-pair for Trees algorithm with those of similar compression algorithms. The obtained results show that that our...

  14. Learning Tree Adjoining Grammars from structures and strings

    NARCIS (Netherlands)

    C. Costa Florêncio

    2012-01-01

    We investigate the learnability of certain subclasses of tree adjoining grammars (TAGs). TAGs are based on two tree-tree operations, and generate structures known as derived trees. The corresponding strings form a mildly context-sensitive language. We prove that even very constrained subclasses of T

  15. A Boy and His Tree 男孩和树

    Institute of Scientific and Technical Information of China (English)

    AmnaLatif

    2005-01-01

    A long time ago, there was a huge apple tree. A little boy loved to come and play around it every day. He climbed to the tree top, ate the apples, took a nap under the shadow...He loved the tree and the tree loved to play with him.

  16. A hierarchical scheme for geodesic anatomical labeling of airway trees

    DEFF Research Database (Denmark)

    Feragen, Aasa; Petersen, Jens; Owen, Megan;

    2012-01-01

    We present a fast and robust supervised algorithm for label- ing anatomical airway trees, based on geodesic distances in a geometric tree-space. Possible branch label configurations for a given unlabeled air- way tree are evaluated based on the distances to a training set of labeled airway trees....

  17. Dissimilarity-based classification of anatomical tree structures

    DEFF Research Database (Denmark)

    Sørensen, Lauge Emil Borch Laurs; Lo, Pechin Chien Pau; Dirksen, Asger;

    2011-01-01

    A novel method for classification of abnormality in anatomical tree structures is presented. A tree is classified based on direct comparisons with other trees in a dissimilarity-based classification scheme. The pair-wise dissimilarity measure between two trees is based on a linear assignment betw...

  18. A Spring Playscape Project: Building a Tree Circle

    Science.gov (United States)

    Keeler, Rusty

    2009-01-01

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

  19. IMPACT OF Global Warming on Trees

    Energy Technology Data Exchange (ETDEWEB)

    Nasrullah Khan [COMSATS Institute of Information Technology, Islamabad (Pakistan); Naeem Abas [2Department of Electrical Engineering, University of Gujrat, Gujrat (Pakistan); Norman Mariun [University Putra Malaysia, Faculty of Engineering, UPM Serdang, Serdang (Malaysia)

    2008-09-30

    Trees store CO{sub 2}, drive food chain, produce oxygen and cause cooling effects through the transpiration process. However, increasing forests to cool the planet needs a lot of care regarding locations and types of trees. Initially it was thought that the city trees fight climate change but later it was found that only tropical trees do the best. Ozone absorption in soil affects its natural carbon sequestration capability. Interaction of plants and soil with changing atmosphere and climate is very complex and not yet understood. Some crops like cotton, wheat and rice are more productive in elevated CO{sub 2} but their response at high temperatures needs further studies (GWDTR, 1997-2007; ITGW, 1990-2008). Use of CO{sub 2} as input raw material in fuel cells might be a revolutionary innovation but there is a long way to go ahead. At this moment we can only start energy education to cope up the time to come. On average CO{sub 2} concentration has been increasing at rate of 2.25ppm/yr from 2004 to 2008 but later from 2007 to 2008 it has been found increasing exponentially at rate of 4ppm/yr. It continues to increase at this rate even after oil peaking then it might exceed 500ppm by 2040-2050. CO{sub 2} concentration in atmosphere was 280 ppm before industrial revolution and in last few centuries it has increased to 385 ppm at an average annual rate of 2 ppm. Weeds normally show poor response to high CO{sub 2} concentrations but crops, fruits and vegetables flourish well. Previous draught cycle was only three years long but recent draught cycle is much longer than earlier (IGWT, 1997-2008). However, few trees in the same constellation are still quite healthy and alive. Some trees were seen dead even close to water canals. Based on literature review and observations recorded in this study it is concluded that high CO{sub 2} induced heat wave (global warming) is responsible for helping beetles and wood ants to eat trees roots and stem to kill them by starvation. The

  20. A VLSI Algorithm for Calculating the Treee to Tree Distance

    Institute of Scientific and Technical Information of China (English)

    徐美瑞; 刘小林

    1993-01-01

    Given two ordered,labeled trees βand α,to find the distance from tree β to tree α is an important problem in many fields,for example,the pattern recognition field.In this paper,a VLSI algorithm for calculating the tree-to-tree distance is presented.The computation structure of the algorithm is a 2-D Mesh with the size m&n.and the time is O(m=n),where m,n are the numbers of nodes of the tree βand tree α,respectively.