WorldWideScience

Sample records for sequoia sempervirens trees

  1. Clonal Spread in Second Growth Stands of Coast Redwood, Sequoia sempervirens

    Science.gov (United States)

    Vladimir Douhovnikoff; Richard S. Dodd

    2007-01-01

    Coast redwood (Sequoia sempervirens) is one of the rare conifers to reproduce successfully through clonal spread. The importance of this mode of reproduction in stand development is largely unknown. Understanding the importance of clonal spread and the spatial structure of clones is crucial for stand management strategies that would aim to maximize...

  2. Proteomic profiling of proteins associated with the rejuvenation of Sequoia sempervirens (D. Don Endl

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    Chen Yu-Ting

    2010-12-01

    Full Text Available Abstract Background Restoration of rooting competence is important for rejuvenation in Sequoia sempervirens (D. Don Endl and is achieved by repeatedly grafting Sequoia shoots after 16 and 30 years of cultivation in vitro. Results Mass spectrometry-based proteomic analysis revealed three proteins that differentially accumulated in different rejuvenation stages, including oxygen-evolving enhancer protein 2 (OEE2, glycine-rich RNA-binding protein (RNP, and a thaumatin-like protein. OEE2 was found to be phosphorylated and a phosphopeptide (YEDNFDGNSNVSVMVpTPpTDK was identified. Specifically, the protein levels of OEE2 increased as a result of grafting and displayed a higher abundance in plants during the juvenile and rejuvenated stages. Additionally, SsOEE2 displayed the highest expression levels in Sequoia shoots during the juvenile stage and less expression during the adult stage. The expression levels also steadily increased during grafting. Conclusion Our results indicate a positive correlation between the gene and protein expression patterns of SsOEE2 and the rejuvenation process, suggesting that this gene is involved in the rejuvenation of Sequoia sempervirens.

  3. Produção de painéis compensados fenólicos com lâminas de madeira de Sequoia sempervirens

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    Setsuo Iwakiri

    Full Text Available Esta pesquisa teve como objetivo avaliar a qualidade dos painéis compensados multilaminados produzidos com lâminas de madeira de Sequoia sempervirens. Foram produzidos em laboratório compensados com cinco lâminas de 2,0 mm de espessura, coladas com resina fenol-formaldeído, com duas diferentes formulações: (A FF = 100; E = 5; CC = 5; A = 5, e (B FF = 100; E = 15; CC = 15; A = 15, e duas gramaturas: 280g/m² e 320 g/m². Os painéis foram prensados com pressão específica de 10 kgf/cm², temperatura de 130 ºC e tempo de prensagem de dez minutos. Foram avaliadas as propriedades de resistência da linha de cola aos esforços de cisalhamento e de flexão estática (módulo de elasticidade e módulo de ruptura, paralelo e perpendicular às fibras. De uma forma geral, as diferentes formulações de cola e gramaturas não afetaram significativamente as propriedades dos painéis, o que representa um aspecto importante sob o ponto de vista econômico. A resistência ao cisalhamento e a percentagem de falhas na madeira dos painéis produzidos com a formulação (B atenderam aos requisitos mínimos da norma EN 314-2 (1993 para painéis de uso externo. Os resultados indicam que as lâminas de Sequoia sempervirens podem ser utilizadas para compor o miolo de painéis compensados para uso externo.

  4. Estimating Leaf Water Potential of Giant Sequoia Trees from Airborne Hyperspectral Imagery

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    Francis, E. J.; Asner, G. P.

    2015-12-01

    Recent drought-induced forest dieback events have motivated research on the mechanisms of tree survival and mortality during drought. Leaf water potential, a measure of the force exerted by the evaporation of water from the leaf surface, is an indicator of plant water stress and can help predict tree mortality in response to drought. Scientists have traditionally measured water potentials on a tree-by-tree basis, but have not been able to produce maps of tree water potential at the scale of a whole forest, leaving forest managers unaware of forest drought stress patterns and their ecosystem-level consequences. Imaging spectroscopy, a technique for remote measurement of chemical properties, has been used to successfully estimate leaf water potentials in wheat and maize crops and pinyon-pine and juniper trees, but these estimates have never been scaled to the canopy level. We used hyperspectral reflectance data collected by the Carnegie Airborne Observatory (CAO) to map leaf water potentials of giant sequoia trees (Sequoiadendron giganteum) in an 800-hectare grove in Sequoia National Park. During the current severe drought in California, we measured predawn and midday leaf water potentials of 48 giant sequoia trees, using the pressure bomb method on treetop foliage samples collected with tree-climbing techniques. The CAO collected hyperspectral reflectance data at 1-meter resolution from the same grove within 1-2 weeks of the tree-level measurements. A partial least squares regression was used to correlate reflectance data extracted from the 48 focal trees with their water potentials, producing a model that predicts water potential of giant sequoia trees. Results show that giant sequoia trees can be mapped in the imagery with a classification accuracy of 0.94, and we predicted the water potential of the mapped trees to assess 1) similarities and differences between a leaf water potential map and a canopy water content map produced from airborne hyperspectral data, 2

  5. Impacts on soils and residual trees from cut-to-length thinning operations in California's redwood forests

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    Kyungrok Hwang; Han-sup Han; Susan E. Marshall; Deborah S. Page-Dumroese

    2017-01-01

    Cut-to-length (CTL) harvest systems have recently been introduced for thinning third-growth, young (<25 years old) redwood forests (Sequoia sempervirens (Lamb. ex D. Don) Endl.) in northern California. This type of harvesting can effective for thinning overstocked stands consisting of small-diameter trees. However, forestland managers and government agencies...

  6. The influence of prefire tree growth and crown condition on postfire mortality of sugar pine following prescribed fire in Sequoia National Park

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    Nesmith, Jonathan C. B.; Das, Adrian J.; O'Hara, Kevin L.; van Mantgem, Phillip J.

    2015-01-01

    Tree mortality is a vital component of forest management in the context of prescribed fires; however, few studies have examined the effect of prefire tree health on postfire mortality. This is especially relevant for sugar pine (Pinus lambertiana Douglas), a species experiencing population declines due to a suite of anthropogenic factors. Using data from an old-growth mixed-conifer forest in Sequoia National Park, we evaluated the effects of fire, tree size, prefire radial growth, and crown condition on postfire mortality. Models based only on tree size and measures of fire damage were compared with models that included tree size, fire damage, and prefire tree health (e.g., measures of prefire tree radial growth or crown condition). Immediately following the fire, the inclusion of different metrics of prefire tree health produced variable improvements over the models that included only tree size and measures of fire damage, as models that included measures of crown condition performed better than fire-only models, but models that included measures of prefire radial growth did not perform better. However, 5 years following the fire, sugar pine mortality was best predicted by models that included measures of both fire damage and prefire tree health, specifically, diameter at breast height (DBH, 1.37 m), crown scorch, 30-year mean growth, and the number of sharp declines in growth over a 30-year period. This suggests that factors that influence prefire tree health (e.g., drought, competition, pathogens, etc.) may partially determine postfire mortality, especially when accounting for delayed mortality following fire.

  7. Impacts of fire management on aboveground tree carbon stocks in Yosemite and Sequoia & Kings Canyon National Parks

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    Matchett, John R.; Lutz, James A.; Tarnay, Leland W.; Smith, Douglas G.; Becker, Kendall M.L.; Brooks, Matthew L.

    2015-01-01

    Forest biomass on Sierra Nevada landscapes constitutes one of the largest carbon stocks in California, and its stability is tightly linked to the factors driving fire regimes. Research suggests that fire suppression, logging, climate change, and present management practices in Sierra Nevada forests have altered historic patterns of landscape carbon storage, and over a century of fire suppression and the resulting accumulation in surface fuels have been implicated in contributing to recent increases in high severity, stand-replacing fires. For over 30 years, fire management at Yosemite (YOSE) and Sequoia & Kings Canyon (SEKI) national parks has led the nation in restoring fire to park landscapes; however, the impacts on the stability and magnitude of carbon stocks have not been thoroughly examined.

  8. Air pollution effects on giant sequoia ecosystems.

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    P.R. Miller; Nancy Grulke; K.W. Stolte

    1994-01-01

    Giant sequoia [Sequoiadendron giganteum (Lindl.) Buchholz] groves are found entirely within the Sierra Nevada mixed-conifer type. Several of its companion tree species, mainly ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (P. jeffreyi Grev. & Balf.), show foliar injury after...

  9. Remote measurement of canopy water content in giant sequoias (Sequoiadendron giganteum) during drought

    Science.gov (United States)

    Martin, Roberta E.; Asner, Gregory P.; Francis, Emily; Ambrose, Anthony; Baxter, Wendy; Das, Adrian J.; Vaughn, Nicolas R.; Paz-Kagan, Tarin; Dawson, Todd E.; Nydick, Koren R.; Stephenson, Nathan L.

    2018-01-01

    California experienced severe drought from 2012 to 2016, and there were visible changes in the forest canopy throughout the State. In 2014, unprecedented foliage dieback was recorded in giant sequoia (Sequoiadendron giganteum) trees in Sequoia National Park, in the southern California Sierra Nevada mountains. Although visible changes in sequoia canopies can be recorded, biochemical and physiological responses to drought stress in giant sequoia canopies are not well understood. Ground-based measurements provide insight into the mechanisms of drought responses in trees, but are often limited to few individuals, especially in trees of tall stature such as giant sequoia. Recent studies demonstrate that remotely measured forest canopy water content (CWC) is a general indicator of canopy response to drought, but the underpinning leaf- to canopy-level causes of observed variation in CWC remain poorly understood. We combined field and airborne remote sensing measurements taken in 2015 and 2016 to assess the biophysical responses of giant sequoias to drought. In 49 study trees, CWC was related to leaf water potential, but not to the other foliar traits, suggesting that changes in CWC were made at whole-canopy rather than leaf scales. We found a non-random, spatially varying pattern in mapped CWC, with lower CWC values at lower elevation and along the outer edges of the groves. This pattern was also observed in empirical measurements of foliage dieback from the ground, and in mapped CWC across multiple sequoia groves in this region, supporting the hypothesis that drought stress is expressed in canopy-level changes in giant sequoias. The fact that we can clearly detect a relationship between CWC and foliage dieback, even without taking into account prior variability or new leaf growth, strongly suggests that remotely sensed CWC, and changes in CWC, are a useful measure of water stress in giant sequoia, and valuable for assessing and managing these iconic forests in drought.

  10. Coping with gravity: the foliar water relations of giant sequoia.

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    Williams, Cameron B; Reese Næsborg, Rikke; Dawson, Todd E

    2017-10-01

    In tall trees, the mechanisms by which foliage maintains sufficient turgor pressure and water content against height-related constraints remain poorly understood. Pressure-volume curves generated from leafy shoots collected crown-wide from 12 large Sequoiadendron giganteum (Lindley) J. Buchholz (giant sequoia) trees provided mechanistic insights into how the components of water potential vary with height in tree and over time. The turgor loss point (TLP) decreased with height at a rate indistinguishable from the gravitational potential gradient and was controlled by changes in tissue osmotica. For all measured shoots, total relative water content at the TLP remained above 75%. This high value has been suggested to help leaves avoid precipitous declines in leaf-level physiological function, and in giant sequoia was controlled by both tissue elasticity and the balance of water between apoplasm and symplasm. Hydraulic capacitance decreased only slightly with height, but importantly this parameter was nearly double in value to that reported for other tree species. Total water storage capacity also decreased with height, but this trend essentially disappeared when considering only water available within the typical range of water potentials experienced by giant sequoia. From summer to fall measurement periods we did not observe osmotic adjustment that would depress the TLP. Instead we observed a proportional shift of water into less mobile apoplastic compartments leading to a reduction in hydraulic capacitance. This collection of foliar traits allows giant sequoia to routinely, but safely, operate close to its TLP, and suggests that gravity plays a major role in the water relations of Earth's largest tree species. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. 76 FR 75558 - Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias, Yosemite...

    Science.gov (United States)

    2011-12-02

    ... tree. Fire plays an important role in giant sequoia ecology, creating canopy openings and releasing soil nutrients needed for seedling establishment. Fire scars on the trees indicate that fires occurred... and sites within the Grove include the parking areas, gift shop, ticket booth, tram staging area...

  12. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  13. Climatic and physiological effects on leaf and tree-ring stable isotopes in California redwoods

    Science.gov (United States)

    Ambrose, A. R.; Baxter, W.; Wong, C.; Dawson, T. E.; Carroll, A.; Voelker, S.

    2016-12-01

    Variation in the stable isotope composition of organic matter can provide important information about environmental change and biological responses to it. We analyzed the stable carbon (d13C) and oxygen (d18O) isotope ratios of leaves and of the cellulose from individual tree-rings of California's two redwood species to examine how these trees have responded to environmental variation and change in both time and space. Analyses of leaf d13C for both coast redwood (Sequoia sempervirens) and giant sequoia (Sequoiadendron giganteum) from throughout their geographical ranges show a marked gradient with tree height for trees of all sizes and ages but no clear difference among species or populations. The gradient is best explained by tree response to changes in both microenvironment and physiology that are known to change with height. In contrast, leaf d18O for both species showed no clear relationship with height but very clear differences between species and populations with giant sequoia displaying a much stronger inferred leaf-level response to the higher evaporative conditions present in the Sierra Nevada mountains as compared to the coast. Both species showed population-level differences with the driest and warmest sites most distinct from all of the others. Intra-annual analyses of d13C and d18O in tree-rings over a 21-year period (1974-1994) were also used to explore how climate and tree response to climate was recorded for both species. These analyses revealed unique (local) climatic effects and response to the climate for each species and population of both redwood species. Most pronounced was a significant increase in intrinsic Water Use Efficiency (iWUE) derived from d13C data over the study period in both species, and a distinct d18O response in relation to drought (e.g. 1976/1977) and to warmer days and nights and above-average precipitation (e.g., 1982-1985). Patterns of co-variation in d13C and d18O in both species suggest that during dry and also warm

  14. The right tree for the job? perceptions of species suitability for the provision of ecosystem services.

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    Smaill, Simeon J; Bayne, Karen M; Coker, Graham W R; Paul, Thomas S H; Clinton, Peter W

    2014-04-01

    Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.

  15. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  16. Leaf to landscape responses of giant sequoia to hotter drought: An introduction and synthesis for the special section

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    Nydick, Koren R.; Stephenson, Nathan L.; Ambrose, Anthony R.; Asner, Gregory P.; Baxter, Wendy L.; Das, Adrian J.; Dawson, Todd E.; Martin, Roberta E.; Paz-Kagan, Tarin

    2018-01-01

    Hotter droughts are becoming more common as climate change progresses, and they may already have caused instances of forest dieback on all forested continents. Learning from hotter droughts, including where on the landscape forests are more or less vulnerable to these events, is critical to help resource managers proactively prepare for the future. As part of our Leaf to Landscape Project, we measured the response of giant sequoia, the world’s largest tree species, to the extreme 2012–2016 hotter drought in California. The project integrated leaf-level physiology measurements, crown-level foliage dieback surveys, and remotely sensed canopy water content (CWC) to shed light on mechanisms and spatial patterns in drought response. Here we summarize initial findings, present a conceptual model of drought response, and discuss management implications; details are presented in the other four articles of the special section on Giant Sequoias and Drought. Giant sequoias exhibited both leaf- and canopy-level responses that were effective in protecting whole-tree hydraulic integrity for the vast majority of individual sequoias. Very few giant sequoias died during the drought compared to other mixed conifer tree species; however, the magnitude of sequoia drought response varied across the landscape. This variability was partially explained by local site characteristics, including variables related to site water balance. We found that low CWC is an indicator of recent foliage dieback, which occurs when stress levels are high enough that leaf-level adjustments alone are insufficient for giant sequoias to maintain hydraulic integrity. CWC or change in CWC may be useful indicators of drought stress that reveal patterns of vulnerability to future hotter droughts. Future work will measure recovery from the drought and strengthen our ability to interpret CWC maps. Our ultimate goal is to produce giant sequoia vulnerability maps to help target management actions, such as

  17. Patterns and correlates of giant sequoia foliage dieback during California’s 2012–2016 hotter drought

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    Stephenson, Nathan L.; Das, Adrian J.; Ampersee, Nicholas J.; Cahill, Kathleen G.; Caprio, Anthony C.; Sanders, John E.; Williams, A. Park

    2018-01-01

    Hotter droughts – droughts in which unusually high temperatures exacerbate the effects of low precipitation – are expected to increase in frequency and severity in coming decades, challenging scientists and managers to identify which parts of forested landscapes may be most vulnerable. In 2014, in the middle of California’s historically unprecedented 2012–2016 hotter drought, we noticed apparently drought-induced foliage dieback in giant sequoias (Sequoiadendron giganteum Lindl. [Buchholz]) in Sequoia and Kings Canyon national parks, California. Characteristics of the dieback were consistent with a controlled process of drought-induced senescence: younger (distal) shoots remained green while older (proximal) shoots were preferentially shed. As part of an ongoing interdisciplinary effort to understand and map sequoia vulnerability to hotter droughts, we reviewed historical records for evidence of previous foliage dieback events, surveyed dieback along trail corridors in eight sequoia groves, and analyzed tree-ring data from a high- and a low-foliage-dieback area. In sharp contrast to the greatly elevated mortality of other coniferous species found at low and middle elevations, we estimate that <1% of sequoias died during the drought. Foliage dieback was notably elevated in 2014 – the most severe single drought year in our 122-year record – but much lower in subsequent years. We found no historical records of similar foliage dieback during previous droughts. Dieback in 2014 was highly variable both within and among groves, ranging from virtually no dieback in some areas to nearly 50% in others. Dieback was highest (1) at low elevations, probably due to higher temperatures, reduced snowpack, and earlier snowmelt; (2) in areas of low adult sequoia densities, which likely reflect intrinsically more stressful sites; and (3) on steep slopes, probably reflecting reduced water availability. Average sequoia ring widths were narrower at the high-dieback than the

  18. Homeopathic Doses of Gelsemium sempervirens Improve the Behavior of Mice in Response to Novel Environments

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    Paolo Bellavite

    2011-01-01

    Full Text Available Gelsemium sempervirens is used in homeopathy for treating patients with anxiety related symptoms, however there have been few experimental studies evaluating its pharmacological activity. We have investigated the effects of homeopathic doses of G. sempervirens on mice, using validated behavioral models. Centesimal (CH dilutions/dynamizations of G. sempervirens, the reference drug diazepam (1 mg/kg body weight or a placebo (solvent vehicle were intraperitoneally delivered to groups of mice of CD1 strain during 8 days, then the effects were assessed by the Light-Dark (LD choice test and by the Open-Field (OF exploration test, in a fully blind manner. In the LD test, the mean time spent in the illuminated area by control and placebo-treated animals was 15.98%, for mice treated with diazepam it increased to 19.91% (P = .047, while with G. sempervirens 5 CH it was 18.11% (P = .341, non-significant. The number of transitions between the two compartments increased with diazepam from 6.19 to 9.64 (P < .001 but not with G. Sempervirens. In the OF test, G. sempervirens 5 CH significantly increased the time spent and the distance traveled in the central zone (P = .009 and P = .003, resp., while diazepam had no effect on these OF test parameters. In a subsequent series of experiments, G. sempervirens 7 and 30 CH also significantly improved the behavioral responses of mice in the OF test (P < .01 for all tested variables. Neither dilutions of G. sempervirens affected the total distance traveled, indicating that the behavioral effect was not due to unspecific changes in locomotor activity. In conclusion, homeopathic doses of G. sempervirens influence the emotional responses of mice to novel environments, suggesting an improvement in exploratory behavior and a diminution of thigmotaxis or neophobia.

  19. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a: giant sequoias

    Science.gov (United States)

    York, Robert A.; Stephenson, Nathan L.; Meyer, Marc; Hanna, Steve; Tadashi, Moody; Caprio, Anthony C.; Battles, John J.

    2013-01-01

    For natural resource managers in the southern Sierra Nevada, giant sequoia requires very little introduction. It receives great attention as an icon of western forests and as a common namesake with the areas where it occurs. While it is a single component of a very complex system, its attention in this assessment and in general is well deserved. Giant sequoia is one of the few "destination species" that attracts a wide swath of the public by nature of it simply being present. It draws people, who otherwise may not travel, to a natural environment. The result is an expansion of the public’s sense of natural resource stewardship. Because park managers could not achieve their mission without public support, this fostering role of giant sequoia is critical for park natural resources and is important for natural resources in general. Despite its social relevance and physical size, we re-emphasize here that the giant sequoia resource is a relatively small component of the ecosystems of the southern Sierra Nevada. As is the case with all of the resources assessed in the NRCA, we focus on giant sequoia with the understanding that other resources will be considered simultaneously when evaluating management decisions that impact giant sequoia. While we attempt to explicitly address the interaction of giant sequoia with other resources and stressors, we also realize that ultimately managers will integrate much more information than is presented here when making decisions that influence giant sequoia. The autecology and management issues surrounding giant sequoia have been thoroughly reviewed elsewhere (Harvey et al. 1980, Aune 1994, Stephenson 1996). Stephenson (1996), in particular, should be reviewed when considering any management decisions that potentially impact giant sequoia. For those who may not be familiar with giant sequoia ecology, a summary of basic information is provided in a table below. In some parts of this assessment, we reproduce text from Stephenson

  20. Changes in gas exchange characteristics during the life span of giant sequoia: Implications for response to current and future concentrations of atmospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Grulke, N.E.; Miller, P.R. (USDA Forest Service, Riverside, CA (United States))

    Native stands of giant sequoia are being exposed to relatively high concentrations of atmospheric ozone produced in urban and agricultural areas upwind. The expected change in environmental conditions over the next 100 y is likely to be unprecendented in the life span (ca 2,500 y) of giant sequoia. Changes in the physiological responses of three age classes of giant sequoia (current year, 12 y and 25 y) to different concentrations of ozone were determined, and age-related differences in sensitivity to pollutants were assessed by examining physiological changes (gas exchange, water use efficiency) across the life span of giant sequoia. The CO[sub 2] exchange rate (CER) was greater in current year (12.1 [mu]mol CO[sub 2]/m[sup 2]s) and 2 year old seedlings (4.8 [mu]mol CO[sub 2]/m[sup 2]s) than in all older trees (average of 3.0 [mu]mol CO[sub 2]/m[sup 2]s). Dark respiration was highest for current year seedlings and was increased twofold in symptotic individuals exposed to elevated ozone concentrations. Stomatal conductance was greater in current-year and 2 year old seedlings (335 and 200 mmol H[sub 2]O/m[sup 2]s), respectively, than in all older trees (50 mmol H[sub 2]O/m[sup 2]s), indicating that the ozone concentration in substomatol cavities is higher in young seedlings than in older trees. Significant changes in water use efficiency occurred in trees between ages 5 and 20 years. It is concluded that giant sequoia seedlings are sensitive to atmospheric ozone until they are ca 5 y old. Low conductance, high water use efficiency, and compact mesophyll all contribute to a natural ozone tolerance, or defense, or both, in foliage of older trees. 11 refs., 1 fig., 1 tab.

  1. Modeling mountain pine beetle habitat suitability within Sequoia National Park

    Science.gov (United States)

    Nguyen, Andrew

    Understanding significant changes in climate and their effects on timber resources can help forest managers make better decisions regarding the preservation of natural resources and land management. These changes may to alter natural ecosystems dependent on historical and current climate conditions. Increasing mountain pine beetle (MBP) outbreaks within the southern Sierra Nevada are the result of these alterations. This study better understands MPB behavior within Sequoia National Park (SNP) and model its current and future habitat distribution. Variables contributing to MPB spread are vegetation stress, soil moisture, temperature, precipitation, disturbance, and presence of Ponderosa (Pinus ponderosa) and Lodgepole (Pinus contorta) pine trees. These variables were obtained using various modeled, insitu, and remotely sensed sources. The generalized additive model (GAM) was used to calculate the statistical significance of each variable contributing to MPB spread and also created maps identifying habitat suitability. Results indicate vegetation stress and forest disturbance to be variables most indicative of MPB spread. Additionally, the model was able to detect habitat suitability of MPB with a 45% accuracy concluding that a geospatial driven modeling approach can be used to delineate potential MPB spread within SNP.

  2. Nectar and pollen production in Arabis procurrens Waldst. & Kit. and Iberis sempervirens L. (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Monika Strzałkowska-Abramek

    2016-04-01

    Full Text Available Ecological environment in urban areas is specific in many aspects. There are evidences that ornamental plants cultivated in local urban gardens may help in conservation of pollinators. In this study, the flowering pattern, the abundance of flowering, nectar and pollen production as well as insect visitation in Arabis procurrens Waldst. & Kit. and Iberis sempervirens L. were investigated. The species were grown in the UMCS Botanical Garden in Lublin, southeastern Poland. Arabis procurrens bloomed from the middle of April until middle of May and I. sempervirens from the end of April until middle of June. In both species, most flowers opened in the morning hours (40–45% of total were opened by 8:00 h GMT + 2 h. The average sugar yield of A. procurrens was ca. 53% lower compared to I. sempervirens (mean = 1.08 g/m2 and 2.32 g/m2, respectively. In both species, considerable differences in the amount of produced sugars were noted between years. The mass of pollen produced in the flowers of A. procurrens was approx. 35% lower compared to that of I. sempervirens (mean = 0.06 mg and 0.09 mg per flower, respectively. Pollen produced per unit area was correlated with the number of flowers. On average, the species produced 1.46 g (A. procurrens and 2.54 g (I. sempervirens of pollen per 1 m2. The flowers of A. procurrens attracted mainly dipterans (56.3% of total visitors, while I. sempervirens lured chiefly solitary bees (47.4% of total visitors, however in both cases, honeybees, bumblebees and lepidopterans were also recorded. The A. procurrens and I. sempervirens due to flowering in early spring period may be promoted for use in small gardens (rock or pot gardens for both aesthetic value and as plants that support insect visitors in nectar and pollen rewards.

  3. Experimental neuropharmacology of Gelsemium sempervirens: Recent advances and debated issues.

    Science.gov (United States)

    Bellavite, Paolo; Bonafini, Clara; Marzotto, Marta

    Gelsemium sempervirens L. (Gelsemium) is traditionally used for its anxiolytic-like properties and its action mechanism in laboratory models are under scrutiny. Evidence from rodent models was reported suggesting the existence of a high sensitivity of central nervous system to anxiolytic power of Gelsemium extracts and Homeopathic dilutions. In vitro investigation of extremely low doses of this plant extract showed a modulation of gene expression of human neurocytes. These studies were criticized in a few commentaries, generated a debate in literature and were followed by further experimental studies from various laboratories. Toxic doses of Gelsemium cause neurological signs characterized by marked weakness and convulsions, while ultra-low doses or high Homeopathic dilutions counteract seizures induced by lithium and pilocarpine, decrease anxiety after stress and increases the anti-stress allopregnanolone hormone, through glycine receptors. Low (non-Homeopathic) doses of this plant or its alkaloids decrease neuropathic pain and c-Fos expression in mice brain and oxidative stress. Due to the complexity of the matter, several aspects deserve interpretation and the main controversial topics, with a focus on the issues of high dilution pharmacology, are discussed and clarified. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

  4. 78 FR 66380 - Final Environmental Impact Statement for the Restoration of the Mariposa Grove of Giant Sequoias...

    Science.gov (United States)

    2013-11-05

    ... sequoia habitat, wetlands, and soundscapes within the Mariposa Grove, this alternative would relocate... for restoration of wetlands, soundscapes, and giant sequoia habitat within the Mariposa Grove by...

  5. Comparative Analysis of Gelsemine and Gelsemium sempervirens Activity on Neurosteroid Allopregnanolone Formation in the Spinal Cord and Limbic System

    Directory of Open Access Journals (Sweden)

    Christine Venard

    2011-01-01

    Full Text Available Centesimal dilutions (5, 9 and 15 cH of Gelsemium sempervirens are claimed to be capable of exerting anxiolytic and analgesic effects. However, basic results supporting this assertion are rare, and the mechanism of action of G. sempervirens is completely unknown. To clarify the point, we performed a comparative analysis of the effects of dilutions 5, 9 and 15 cH of G. sempervirens or gelsemine (the major active principle of G. sempervirens on allopregnanolone (3α,5α-THP production in the rat limbic system (hippocampus and amygdala or H-A and spinal cord (SC. Indeed, H-A and SC are two pivotal structures controlling, respectively, anxiety and pain that are also modulated by the neurosteroid 3α,5α-THP. At the dilution 5 cH, both G. sempervirens and gelsemine stimulated [3H]progesterone conversion into [3H]3α,5α-THP by H-A and SC slices, and the stimulatory effect was fully (100% reproducible in all assays. The dilution 9 cH of G. sempervirens or gelsemine also stimulated 3α,5α-THP formation in H-A and SC but the reproducibility rate decreased to 75%. At 15 cH of G. sempervirens or gelsemine, no effect was observed on 3α,5α-THP neosynthesis in H-A and SC slices. The stimulatory action of G. sempervirens and gelsemine (5 cH on 3α,5α-THP production was blocked by strychnine, the selective antagonist of glycine receptors. Altogether, these results, which constitute the first basic demonstration of cellular effects of G. sempervirens, also offer interesting possibilities for the improvement of G. sempervirens-based therapeutic strategies.

  6. 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.

  7. Communicating the role of science in managing giant sequoia groves

    Science.gov (United States)

    Douglas D. Pilrto; Robert R. Rogers; Mary Chislock Bethke

    1997-01-01

    Management of giant sequoia groves has been and continues to be a hotly debated issue. The debate has reached Congress, with all parties seeking resolution as to what constitutes an ecologically and publicly acceptable management approach. Determining the correct management approach and communicating that approach to the general public is the crux of the problem....

  8. Management of Giant Sequoia on Mountain Home Demonstration State Forest

    Science.gov (United States)

    Norman J. Benson

    1986-01-01

    Established in 1946, the Mountain Home Demonstration State Forest, Tulare County, California, is managed by the California Department of Forestry. It is a multiple-use forest with recreation as its primary focus, although timber management has always played an important role. Giant sequoia (Sequoiadendron giganteum [Lindl. ] Buchholz) occurs in...

  9. Landscape-scale variation in canopy water content of giant sequoias during drought

    Science.gov (United States)

    Paz-Kagan, Tarin; Vaughn, Nicolas R.; Martin, Roberta E.; Brodrick, Philip G.; Stephenson, Nathan L.; Das, Adrian; Nydick, Koren R.; Asner, Gregory P.

    2018-01-01

    Recent drought (2012–2016) caused unprecedented foliage dieback in giant sequoias (Sequoiadendron giganteum), a species endemic to the western slope of the southern Sierra Nevada in central California. As part of an effort to understand and map sequoia response to droughts, we studied the patterns of remotely sensed canopy water content (CWC), both within and among sequoia groves in two successive years during the drought period (2015 and 2016). Our aims were: (1) to quantify giant sequoia responses to severe drought stress at a landscape scale using CWC as an indicator of crown foliage status, and (2) to estimate the effect of environmental correlates that mediate CWC change within and among giant sequoia groves. We utilized airborne high fidelity imaging spectroscopy (HiFIS) and light detection and ranging (LiDAR) data from the Carnegie Airborne Observatory to assess giant sequoia foliage status during 2015 and 2016 of the 2012–2016 droughts. A series of statistical models were generated to classify giant sequoias and to map their location in Sequoia and Kings Canyon National Parks (SEKI) and vicinity. We explored the environmental correlates and the spatial patterns of CWC change at the landscape scale. The mapped CWC was highly variable throughout the landscape during the two observation years, and proved to be most closely related to geological substrates, topography, and site-specific water balance. While there was an overall net gain in sequoia CWC between 2015 and 2016, certain locations (lower elevations, steeper slopes, areas more distant from surface water sources, and areas with greater climate water deficit) showed CWC losses. In addition, we found greater CWC loss in shorter sequoias and those growing in areas with lower sequoia stem densities. Our results suggest that CWC change indicates sequoia response to droughts across landscapes. Long-term monitoring of giant sequoia CWC will likely be useful for modeling and predicting their population

  10. Biological and Management Implications of Fire-Pathogen Interactions in the Giant Sequoia Ecosystem

    Science.gov (United States)

    Douglas D. Piirto; John R. Parmeter; Fields W. Cobb; Kevin L. Piper; Amy C. Workinger; William J. Otrosina

    1998-01-01

    An overriding management goal for national parks is the maintenance or, where necessary, the restoration of natural ecological processes. In Sequoia-Kings Canyon and Yosemite National Parks, there is concern about the effects of fire suppression on the giant sequoia-mixed conifer forest ecosystem. The National Park Service is currently using prescribed fire management...

  11. 78 FR 16294 - Draft Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias...

    Science.gov (United States)

    2013-03-14

    ... Environmental Impact Statement for Restoration of the Mariposa Grove of Giant Sequoias, Yosemite National Park, Madera, and Mariposa Counties, CA AGENCY: National Park Service, Interior. ACTION: Notice of availability... the Mariposa Grove of giant sequoias in Yosemite National Park. This Draft EIS presents three...

  12. Visual Impacts of Prescribed Burning on Mixed Conifer and Giant Sequoia Forests

    Science.gov (United States)

    Lin Cotton; Joe R. McBride

    1987-01-01

    Prescribed burning programs have evolved with little concern for the visual impact of burning and the potential prescribed burning can have in managing the forest scene. Recent criticisms by the public of the prescribed burning program at Sequoia National Park resulted in an outside review of the National Park fire management programs in Sequoia, Kings Canyon, and...

  13. Magnetic record associated with tree ring density: Possible climate proxy

    Czech Academy of Sciences Publication Activity Database

    Kletetschka, Günther; Pruner, Petr; Venhodová, Daniela; Kadlec, Jaroslav

    2007-01-01

    Roč. 8, - (2007), s. 1-11 ISSN 1467-4866 Institutional research plan: CEZ:AV0Z3013912 Keywords : palaeo-climatic indicator * sequoia tree * magnetic properties Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.842, year: 2007

  14. Black bear damage to northwestern conifers in California: a review

    Science.gov (United States)

    Kenneth O. Fulgham; Dennis Hosack

    2017-01-01

    A total of 789 black bear damaged trees were investigate over a multi-year period on 14 different study sites chosen on lands of four participating timber companies. The sites ranged from 30 to 50 years of age. Four different conifer species were found to have black bear damage: coastal redwood (Sequoia sempervirens (D. Don) Endl.), Douglas-fir (...

  15. Bark water uptake promotes localized hydraulic recovery in coastal redwood crown

    Science.gov (United States)

    J. Mason Earles; Or Sperling; Lucas C. R. Silva; Andrew J. McElrone; Craig R. Brodersen; Malcolm P. North; Maciej A. Zwieniecki

    2015-01-01

    Coastal redwood (Sequoia sempervirens), the world’s tallest tree species, rehydrates leaves via foliar water uptake during fog/rain events. Here we examine if bark also permits water uptake in redwood branches, exploring potential flow mechanisms and biological significance. Using isotopic labelling and microCT imaging, we observed that water...

  16. Inbreeding depression in selfs of redwood

    Science.gov (United States)

    W. J. Libby; B. G. McCutchan; C. I. Millar

    1981-01-01

    Given the polyploid chromosome constitution of Sequoia sempervirens, there was reason to question whether it would exhibit inbreeding depression. Preliminary results from studies of self and related outcross families are reported as a guide to the selection of trees for redwood seed orchards and breeding-orchards. The data indicate that, compared to...

  17. Coast redwood live crown and sapwood

    Science.gov (United States)

    John-Pascal Berrill; Jesse L. Deffress; Jessica M. Engle

    2012-01-01

    Understanding crown rise and sapwood taper will help meet management objectives such as producing long branch-free boles for clear wood and old-growth restoration, or producing sawlogs with a high proportion of heartwood. Coast redwood (Sequoia sempervirens) tree crown ratio data were collected 20 years after partial harvesting in a 65-year-old second growth stand....

  18. Multiyear impacts of partial throughfall exclusion on Buxus sempervirens in a Mediterranean forest

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Calcerrada, J.; Letts, M. G.; Rolo, V.; Roset, S.; Rambal, S.

    2013-09-01

    Aim of study:We examined the impact of sustained partial throughfall exclusion on the functional performance of Buxus sempervirens L. in the understory of a Mediterranean evergreen forest. We further considered whether any impacts of throughfall exclusion were affected by light availability. Area of study: The study was conducted in the south of France. Material and methods: Several leaf physiological and branch structural traits were measured along a light gradient after seven years from the onset of a throughfall exclusion experiment (TEE). The results were analysed along with annual growth and survival data. Main results: Plant mortality was nil in both the throughfall exclusion and control treatments. Stem diameter growth was reduced by 39% in plants subjected to throughfall exclusion, but this difference was only significant at the p = 0.10 significance level. Leaf physiology remained unaffected by the TEE, but small changes were evident in branch structural traits in high light microsites following throughfall exclusion; branches had lower wood density in the TEE plot, and more biomass was partitioned to leaves relative to stems. Research highlights: These changes do not seem to reflect an acclimatory response that would enhance drought tolerance. Instead, we suggest that these drought effects might exacerbate vulnerability to xylem cavitation in the more open microsites. Reduced growth and increased vulnerability to drought may indicate an incipient decline in plant vitality following TEE. The extension of observations to the whole-plant level and longer periods will elucidate the consequences of these observations for plant fitness, and permit verification of the positive effect of shade on Buxus sempervirens under increased drought. (Author)

  19. The effects of raking on sugar pine mortality following prescribed fire in Sequoia and Kings Canyon National Parks, California, USA

    Science.gov (United States)

    Nesmith, Jonathan C. B.; O'Hara, Kevin L.; van Mantgem, Phillip J.; de Valpine, Perry

    2010-01-01

    Prescribed fire is an important tool for fuel reduction, the control of competing vegetation, and forest restoration. The accumulated fuels associated with historical fire exclusion can cause undesirably high tree mortality rates following prescribed fires and wildfires. This is especially true for sugar pine (Pinus lambertiana Douglas), which is already negatively affected by the introduced pathogen white pine blister rust (Cronartium ribicola J.C. Fisch. ex Rabenh). We tested the efficacy of raking away fuels around the base of sugar pine to reduce mortality following prescribed fire in Sequoia and Kings Canyon national parks, California, USA. This study was conducted in three prescribed fires and included 457 trees, half of which had the fuels around their bases raked away to mineral soil to 0.5 m away from the stem. Fire effects were assessed and tree mortality was recorded for three years after prescribed fires. Overall, raking had no detectable effect on mortality: raked trees averaged 30% mortality compared to 36% for unraked trees. There was a significant effect, however, between the interaction of raking and average pre-treatment forest floor fuel depth: the predicted probability of survival of a 50 cm dbh tree was 0.94 vs. 0.96 when average pre-treatment fuel depth was 0 cm for a raked and unraked tree, respectively. When average pre-treatment forest floor fuel depth was 30 cm, the predicted probability of survival for a raked 50 cm dbh tree was 0.60 compared to only 0.07 for an unraked tree. Raking did not affect mortality when fire intensity, measured as percent crown volume scorched, was very low (0% scorch) or very high (>80% scorch), but the raking treatment significantly increased the proportion of trees that survived by 9.6% for trees that burned under moderate fire intensity (1% to 80% scorch). Raking significantly reduced the likelihood of bole charring and bark beetle activity three years post fire. Fuel depth and anticipated fire intensity need

  20. Isozyme markers associated with O3 tolerance indicate shift in genetic structure of ponderosa and Jeffrey pine in Sequoia National Park, California

    International Nuclear Information System (INIS)

    Staszak, J.; Grulke, N.E.; Marrett, M.J.; Prus-Glowacki, W.

    2007-01-01

    Effects of canopy ozone (O 3 ) exposure and signatures of genetic structure using isozyme markers associated with O 3 tolerance were analyzed in ∼20-, ∼80-, and >200-yr-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. and Balf.) in Sequoia National Park, California. For both species, the number of alleles and genotypes per loci was higher in parental trees relative to saplings. In ponderosa pine, the heterozygosity value increased, and the fixation index indicated reduction of homozygosity with increasing tree age class. The opposite tendencies were observed for Jeffrey pine. Utilizing canopy attributes known to be responsive to O 3 exposure, ponderosa pine was more symptomatic than Jeffrey pine, and saplings were more symptomatic than old growth trees. We suggest that these trends are related to differing sensitivity of the two species to O 3 exposure, and to higher O 3 exposures and drought stress that younger trees may have experienced during germination and establishment. - Genetic variation in isozyme markers associated with ozone tolerance differed between parental trees and their progeny in two closely related species of yellow pine

  1. Isozyme markers associated with O{sub 3} tolerance indicate shift in genetic structure of ponderosa and Jeffrey pine in Sequoia National Park, California

    Energy Technology Data Exchange (ETDEWEB)

    Staszak, J. [A Mickiewicz University, Genetics Department, ul. Umultowska 89, 61-614 Poznan (Poland); Grulke, N.E. [USDA Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)], E-mail: ngrulke@fs.fed.us; Marrett, M.J. [5184 Tower Road, Riverside, CA 92506 (United States); Prus-Glowacki, W. [A Mickiewicz University, Genetics Department, ul. Umultowska 89, 61-614 Poznan (Poland)

    2007-10-15

    Effects of canopy ozone (O{sub 3}) exposure and signatures of genetic structure using isozyme markers associated with O{sub 3} tolerance were analyzed in {approx}20-, {approx}80-, and >200-yr-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. and Balf.) in Sequoia National Park, California. For both species, the number of alleles and genotypes per loci was higher in parental trees relative to saplings. In ponderosa pine, the heterozygosity value increased, and the fixation index indicated reduction of homozygosity with increasing tree age class. The opposite tendencies were observed for Jeffrey pine. Utilizing canopy attributes known to be responsive to O{sub 3} exposure, ponderosa pine was more symptomatic than Jeffrey pine, and saplings were more symptomatic than old growth trees. We suggest that these trends are related to differing sensitivity of the two species to O{sub 3} exposure, and to higher O{sub 3} exposures and drought stress that younger trees may have experienced during germination and establishment. - Genetic variation in isozyme markers associated with ozone tolerance differed between parental trees and their progeny in two closely related species of yellow pine.

  2. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

    Science.gov (United States)

    Huber, Ann; Das, Adrian; Wenk, Rebecca; Haultain, Sylvia

    2013-01-01

    Database (CNDDB 2010a). There are an additional 66 taxa not formally listed by CNDDB that are recognized as having special status because their distribution is restricted to the Sierra Nevada. Special status plants are distributed throughout the two parks and inhabit a wide range of environments along the length of the elevation gradient that characterizes these parks. Ideally, we would assess the condition (status and trends) of each of the taxa on the SEKI special status plant list, documenting current population sizes, demographic rates and demographic trends. We would also hope to quantify the effects of individual stressors on each species based on existing monitoring and research. However, no data are available for most of the species on the special status plant list. For those few species (12 herbaceous species and two tree species) for which we possess some change over time information, the data are not adequate to make a competent assessment. Note that we have not explored the tree demographic information in any detail, as is covered in the NRCA Intact Forest/Five Needle Pines and Sequoia chapters. In general, we are unable to present an ‗integrity‘ metric for special status species in the parks, since the data to quantify the condition of each species in such a manner is not available. In contrast, the park does possess substantial data describing biodiversity in the parks. Therefore, our analysis focuses on describing the distribution and rarity of special status plants within the parks, with a particular focus on assessing the spatial distribution of species richness. We hope that such information will prove useful to park managers in determining which areas in the parks merit the most attention (for example in developing monitoring protocols). We also assess potential vulnerability of special status species to the stressors chosen by the NRCA working group, using both park data and available literature. As a first step, we spent considerable effort

  3. The spectral response of Buxus sempervirens to different types of environmental stress - A laboratory experiment

    Science.gov (United States)

    de Jong, Steven M.; Addink, Elisabeth A.; Hoogenboom, Priscilla; Nijland, Wiebe

    2012-11-01

    The European Mediterranean regions are expected to encounter drier summer conditions and warmer temperatures for the winter of +2 °C and of +5 °C for the summer in the next six decennia. As a result the natural vegetation will face harsher conditions due to lower water availability, longer summer droughts and higher temperatures resulting in plant stress conditions. To monitor vegetation conditions like stress and leaf area index dynamics in our study area in Mediterranean France we use earth observation techniques like imaging spectroscopy. To assist image analysis interpretation we carried out a laboratory experiment to investigate the spectral and visible response of Buxus sempervirens, a common Mediterranean species, to five different types of stress: drought, drought-and-heat, light deprivation, total saturation and chlorine poisoning. For 52 days plants were subjected to stress. We collected data on the visible and spectral signs, and calculated thirteen vegetation indices. The plant's response time to different stress types varied from 10 to 32 days. Spectroscopic techniques revealed plant stress up to 15 days earlier than visual inspection. Visible signs of stress of the plants included curling and shrinking of the leaves, de-colouring of the leaves, leaves becoming breakable, opening up of the plant's canopy and sagging of the branches. Spectral signs of stress occurred first in the water absorption bands at 1450 and 1940 nm, followed by reduced absorption in the visible wavelengths, and next by reduced reflectance in near infrared. Light deprivation did not result in any stress signs, while drought, drought and heat and chlorine poisoning resulted in significant stress. The spectral response did not show differences for different stress types. Analysis of the vegetation indices identified the Carter-2 (R695/R760), the Red-Green Index (R690/R550) and the Vogelman-2 (R734 - R747)/(R715 + R726) as the best performing ones to identify stress. The lab

  4. Fungistatic Activity Of Essential Oils Extracted from Peumus boldus Mol., Laureliopsis philippiana (Looser Schodde and Laurelia sempervirens (Ruiz & Pav. Tul. (Chilean Monimiaceae Actividad Fungistática de Extractos de Aceites Asenciales de Peumus boldus Mol., Laureliopsis philippiana (Looser Schodde y Laurelia sempervirens (Ruiz & Pav. Tul. (Monimiaceae chilenas

    Directory of Open Access Journals (Sweden)

    Magalis Bittner

    2009-03-01

    Full Text Available Components of essential oils from the Chilean Monimiaceae, boldo (Peumus boldus Mol., tepa (Laureliopsis philippiana (Looser Schodde, and laurel (Laurelia sempervirens (Ruiz & Pav. Tul. were determined using Gas Chromatography- Mass Spectrometry (GCMS and fungistatic activity of the essential oils was tested against Rhizoctonia solani Kühn (Donk, Pythium irregulare Buisman, Ceratocystis pilifera (Fr. C. Moreau, Phragmidium violaceum (Schultz G. Winter, and Fusarium oxysporum Schltdl. The essential oils of the Monimiaceae species shared some common components; all three had the 3-carene, α-phellandrene, and α-pinene terpenes. L. philippiana and L. sempervirens also had safrole.The main components were ascaridol in P. boldus oil, 3-carene in L. philippiana, and safrole in L. sempervirens. The essential oil from L. sempervirens showed the highest fungistatic activity with significant differences in dose as well as exposure. P. violaceum was the most sensitive strain and P. irregulare the most resistant of all the essential oils (P. boldus extract affected growth by only 19%. Therefore, essential oils from these three plants could be used to control the fungal strains studied.Se determinaron los compuestos de aceites esenciales de Monimiaceae chilenas, boldo (Peumus boldus Mol., tepa (Laureliopsis philippiana (Looser Schodde, y laurel (Laurelia sempervirens (Ruiz & Pav. Tul. a través de cromatografía de gas con espectrometría de masas (CG-EM y se midió la actividad fungistática de los aceites sobre los hongos Rhizoctonia solani Kühn (Donk, Pythium irregulare Buisman, Ceratocystis pilifera (Fr. C. Moreau, Phragmidium violaceum (Schultz Winter y Fusarium oxysporum Schltdl. Los aceites esenciales de las especies de Monimiaceae tienen algunos compuestos en común; en las especies estudiadas se encontró que todos tenían los terpenos 3-careno, α-felandreno, y α-pineno. L. philippiana y L. sempervirens además tienen safrol. En cambio

  5. High-resolution 3D simulations of NIF ignition targets performed on Sequoia with HYDRA

    Science.gov (United States)

    Marinak, M. M.; Clark, D. S.; Jones, O. S.; Kerbel, G. D.; Sepke, S.; Patel, M. V.; Koning, J. M.; Schroeder, C. R.

    2015-11-01

    Developments in the multiphysics ICF code HYDRA enable it to perform large-scale simulations on the Sequoia machine at LLNL. With an aggregate computing power of 20 Petaflops, Sequoia offers an unprecedented capability to resolve the physical processes in NIF ignition targets for a more complete, consistent treatment of the sources of asymmetry. We describe modifications to HYDRA that enable it to scale to over one million processes on Sequoia. These include new options for replicating parts of the mesh over a subset of the processes, to avoid strong scaling limits. We consider results from a 3D full ignition capsule-only simulation performed using over one billion zones run on 262,000 processors which resolves surface perturbations through modes l = 200. We also report progress towards a high-resolution 3D integrated hohlraum simulation performed using 262,000 processors which resolves surface perturbations on the ignition capsule through modes l = 70. These aim for the most complete calculations yet of the interactions and overall impact of the various sources of asymmetry for NIF ignition targets. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  6. A comparison of effects from prescribed fires and wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks

    Science.gov (United States)

    Nesmith, C.B.; Caprio, Anthony C.; Pfaff, Anne H.; McGinnis, Thomas W.; Keeley, Jon E.

    2011-01-01

    Current goals for prescription burning are focused on measures of fuel consumption and changes in forest density. These benchmarks, however, do not address the extent to which prescription burning meets perceived ecosystem needs of heterogeneity in burning, both for overstory trees and understory herbs and shrubs. There are still questions about how closely prescribed fires mimic these patterns compared to natural wildfires. This study compared burn patterns of prescribed fires and managed unplanned wildfires to understand how the differing burning regimes affect ecosystem properties. Measures of forest structure and fire severity were sampled in three recent prescribed fires and three wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks. Fine scale patterns of fire severity and heterogeneity were compared between fire types using ground-based measures of fire effects on fuels and overstory and understory vegetation. Prescribed fires and wildfires managed for resource objectives displayed similar patterns of overstory and understory fire severity, heterogeneity, and seedling and sapling survival. Variation among plots within the same fire was always greater than between fire types. Prescribed fires can provide burned landscapes that approximate natural fires in many ways. It is recognized that constraints placed on when wildfires managed for resource objectives are allowed to burn freely may bias the range of conditions that might have been experienced under more natural conditions. Therefore they may not exactly mimic natural wildfires. Overall, the similarity in fire effects that we observed between prescribed fires and managed wildfires indicate that despite the restrictions that are often placed on prescribed fires, they appear to be creating post-fire conditions that approximate natural fires when assessed on a fine spatial scale.

  7. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 22: climatic change

    Science.gov (United States)

    Das, Adrian J.; Stephenson, Nathan L.

    2013-01-01

    Climate is a master controller of the structure, composition, and function of biotic communities, affecting them both directly, through physiological effects, and indirectly, by mediating biotic interactions and by influencing disturbance regimes. Sequoia and Kings Canyon National Park’s (SEKI’s) dramatic elevational changes in biotic communities -- from warm mediterranean to cold alpine -- are but one manifestation of climate’s overarching importance in shaping SEKI’s landscape. Yet humans are now altering the global climate, with measurable effects on ecosystems (IPCC 2007). Over the last few decades across the western United States, human-induced climatic changes have likely contributed to observed declines in fraction of precipitation falling as snow and snowpack water content (Mote et al. 2005, Knowles et al. 2006), advance in spring snowmelt (Stewart et al. 2005, Barnett et al. 2008), and consequent increase in area burned in wildfires (Westerling et al. 2006). In the Sierra Nevada, warming temperatures have likely contributed to observed glacial recession (Basagic 2008), uphill migration of small mammals (Moritz et al. 2008), and increasing tree mortality rates (van Mantgem and Stephenson 2007, van Mantgem et al. 2009). More substantial changes can be expected for the future (e.g., IPCC 2007). Given the central importance of climate and climatic changes, we sought to describe long-term trends in temperature and precipitation at SEKI. Time and budget constraints limited us to analyses of mean annual temperature and mean annual precipitation, using readily-available data. If funds become available in the future, further analyses will be needed to analyze trends by season, trends in daily minimum and maximum temperatures, and so on. We chose to analyze data from individual weather stations rather than use interpolated climatic data from sources such as PRISM (http://www.prism.oregonstate.edu/). In topographically complex mountainous regions with few

  8. Comparative study of two coniferous species (Pinus pinaster Aiton and Cupressus sempervirens L. var. dupreziana [A. Camus] Silba) essential oils: chemical composition and biological activity

    OpenAIRE

    Amri, Ismail; Hanana, Mohsen; Gargouri, Samia; Jamoussi, Bassem; Hamrouni, Lamia

    2013-01-01

    Maritime pine (Pinus pinaster Aiton) and Saharan cypress (Cupressus sempervirens L. var. dupreziana [A. Camus] Silba) are two cone-bearing seed coniferous woody plants. The chemical composition of their essential oils, isolated from needles and leaves by hydrodistillation, was analyzed with gas chromatography (GC) and gas chromatography mass spectrometry (GC/MS). A total of 66 and 28 compounds were identified, which represented 99.5% and 98.9% of total pine and cypress oils, respectively. Pin...

  9. Monte Carlo simulation of the resolution volume for the SEQUOIA spectrometer

    Directory of Open Access Journals (Sweden)

    Granroth G.E.

    2015-01-01

    Full Text Available Monte Carlo ray tracing simulations, of direct geometry spectrometers, have been particularly useful in instrument design and characterization. However, these tools can also be useful for experiment planning and analysis. To this end, the McStas Monte Carlo ray tracing model of SEQUOIA, the fine resolution fermi chopper spectrometer at the Spallation Neutron Source (SNS of Oak Ridge National Laboratory (ORNL, has been modified to include the time of flight resolution sample and detector components. With these components, the resolution ellipsoid can be calculated for any detector pixel and energy bin of the instrument. The simulation is split in two pieces. First, the incident beamline up to the sample is simulated for 1 × 1011 neutron packets (4 days on 30 cores. This provides a virtual source for the backend that includes the resolution sample and monitor components. Next, a series of detector and energy pixels are computed in parallel. It takes on the order of 30 s to calculate a single resolution ellipsoid on a single core. Python scripts have been written to transform the ellipsoid into the space of an oriented single crystal, and to characterize the ellipsoid in various ways. Though this tool is under development as a planning tool, we have successfully used it to provide the resolution function for convolution with theoretical models. Specifically, theoretical calculations of the spin waves in YFeO3 were compared to measurements taken on SEQUOIA. Though the overall features of the spectra can be explained while neglecting resolution effects, the variation in intensity of the modes is well described once the resolution is included. As this was a single sharp mode, the simulated half intensity value of the resolution ellipsoid was used to provide the resolution width. A description of the simulation, its use, and paths forward for this technique will be discussed.

  10. Antiprotozoal Activity of Buxus sempervirens and Activity-Guided Isolation of O-tigloylcyclovirobuxeine-B as the Main Constituent Active against Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Julia B. Althaus

    2014-05-01

    Full Text Available Buxus sempervirens L. (European Box, Buxaceae has been used in ethnomedicine to treat malaria. In the course of our screening of plant extracts for antiprotozoal activity, a CH2Cl2 extract from leaves of B. sempervirens showed selective in vitro activity against Plasmodium falciparum (IC50 = 2.79 vs. 20.2 µg/mL for cytotoxicity against L6 rat cells. Separation of the extract by acid/base extraction into a basic and a neutral non-polar fraction led to a much more active and even more selective fraction with alkaloids while the fraction of non-polar neutral constituents was markedly less active than the crude extract. Thus, the activity of the crude extract could clearly be attributed to alkaloid constituents. Identification of the main triterpene-alkaloids and characterization of the complex pattern of this alkaloid fraction was performed by UHPLC/+ESI-QTOF-MS analyses. ESI-MS/MS target-guided larger scale preparative separation of the alkaloid fraction was performed by ‘spiral coil-countercurrent chromatography’. From the most active subfraction, the cycloartane alkaloid O-tigloylcyclovirobuxeine-B was isolated and evaluated for antiplasmodial activity which yielded an IC50 of 0.455 µg/mL (cytotoxicity against L6 rat cells: IC50 = 9.38 µg/mL. O-tigloylcyclovirobuxeine-B is thus most significantly responsible for the high potency of the crude extract.

  11. Bioactivity of Peumus boldus Molina, Laurelia sempervirens (Ruiz & Pav. Tul. and Laureliopsis philippiana (Looser Schodde (Monimiacea essential oils against Sitophilus zeamais Motschulsky

    Directory of Open Access Journals (Sweden)

    Carmen Herrera-Rodríguez

    2015-09-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky is one of most important pest of stored seeds worldwide, but its current control method is based on the use of synthetic insecticides, usually leading to undesirable problems such as insecticide residues on treated food, human intoxications, and insect resistance development. Therefore the search of friendly alternative methods is required. The aim of this study was to assess, under laboratory conditions, the insecticidal properties of Peumus boldus Molina, Laurelia sempervirens (Ruiz & Pav. Tul., and Laureliopsis philippiana (Looser Schodde essential oils against S. zeamais. The phytochemical analysis of the three essential oils showed 1,8-cineole, safrole and methyleugenol as the common components; all of them documented with insecticidal activity from essential oils from other plant species. The highest toxicity (100% mortality of these three oils acting as a contact insecticide was observed at 24 h exposure at 4% concentration. The estimated LC50 values for P. boldus, L. sempervirens, and L. philippiana were 0.37, 1.02, and 0.28 μL g-1, respectively. Peumus boldus exhibited the highest fumigant activity with 100% adult mortality at 30 μL oil L-1 air. At ≥ 0.5% (v/w concentration, all essential oils showed repellent activity. These three essential oils showed a promissory insecticidal activity against the maize weevil.

  12. Demography of the California spotted owl in the Sierra National Forest and Sequoia/Kings Canyon National Parks

    Science.gov (United States)

    George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary P. Eberlein

    2002-01-01

    Nine years (1990–1998) of demographic data on California spotted owls (Strix occidentalis occidentalis) in two study areas on the western slopes of the Sierra Nevada—one in the Sierra National Forest (SNF), the other in Sequoia/Kings Canyon National Parks (SNP)—are summarized. Numbers of territorial owls fluctuated from 85 to 50 in SNF and 80 to 58...

  13. Laboratory evaluation of the Sequoia Scientific LISST-ABS acoustic backscatter sediment sensor

    Science.gov (United States)

    Snazelle, Teri T.

    2017-12-18

    Sequoia Scientific’s LISST-ABS is an acoustic backscatter sensor designed to measure suspended-sediment concentration at a point source. Three LISST-ABS were evaluated at the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF). Serial numbers 6010, 6039, and 6058 were assessed for accuracy in solutions with varying particle-size distributions and for the effect of temperature on sensor accuracy. Certified sediment samples composed of different ranges of particle size were purchased from Powder Technology Inc. These sediment samples were 30–80-micron (µm) Arizona Test Dust; less than 22-µm ISO 12103-1, A1 Ultrafine Test Dust; and 149-µm MIL-STD 810E Silica Dust. The sensor was able to accurately measure suspended-sediment concentration when calibrated with sediment of the same particle-size distribution as the measured. Overall testing demonstrated that sensors calibrated with finer sized sediments overdetect sediment concentrations with coarser sized sediments, and sensors calibrated with coarser sized sediments do not detect increases in sediment concentrations from small and fine sediments. These test results are not unexpected for an acoustic-backscatter device and stress the need for using accurate site-specific particle-size distributions during sensor calibration. When calibrated for ultrafine dust with a less than 22-µm particle size (silt) and with the Arizona Test Dust with a 30–80-µm range, the data from sensor 6039 were biased high when fractions of the coarser (149-µm) Silica Dust were added. Data from sensor 6058 showed similar results with an elevated response to coarser material when calibrated with a finer particle-size distribution and a lack of detection when subjected to finer particle-size sediment. Sensor 6010 was also tested for the effect of dissimilar particle size during the calibration and showed little effect. Subsequent testing revealed problems with this sensor, including an inadequate temperature

  14. Sapwood area - leaf area relationships for coast redwood

    OpenAIRE

    Stancioiu, P T; O'Hara, K L

    2005-01-01

    Coast redwood (Sequoia sempervirens (D. Don) Endl.) trees in different canopy strata and crown positions were sampled to develop relationships between sapwood cross-sectional area and projected leaf area. Sampling occurred during the summers of 2000 and 2001 and covered tree heights ranging from 7.7 to 45.2 m and diameters at breast height ranging from 9.4 to 92.7 cm. Foliage morphology varied greatly and was stratified into five types based on needle type (sun or shade) and twig color. A str...

  15. A lightning multiple casualty incident in Sequoia and Kings Canyon National Parks.

    Science.gov (United States)

    Spano, Susanne J; Campagne, Danielle; Stroh, Geoff; Shalit, Marc

    2015-03-01

    Multiple casualty incidents (MCIs) are uncommon in remote wilderness settings. This is a case report of a lightning strike on a Boy Scout troop hiking through Sequoia and Kings Canyon National Parks (SEKI), in which the lightning storm hindered rescue efforts. The purpose of this study was to review the response to a lightning-caused MCI in a wilderness setting, address lightning injury as it relates to field management, and discuss evacuation options in inclement weather incidents occurring in remote locations. An analysis of SEKI search and rescue data and a review of current literature were performed. A lightning strike at 10,600 feet elevation in the Sierra Nevada Mountains affected a party of 5 adults and 7 Boy Scouts (age range 12 to 17 years old). Resources mobilized for the rescue included 5 helicopters, 2 ambulances, 2 hospitals, and 15 field and 14 logistical support personnel. The incident was managed from strike to scene clearance in 4 hours and 20 minutes. There were 2 fatalities, 1 on scene and 1 in the hospital. Storm conditions complicated on-scene communication and evacuation efforts. Exposure to ongoing lightning and a remote wilderness location affected both victims and rescuers in a lightning MCI. Helicopters, the main vehicles of wilderness rescue in SEKI, can be limited by weather, daylight, and terrain. Redundancies in communication systems are vital for episodes of radio failure. Reverse triage should be implemented in lightning injury MCIs. Education of both wilderness travelers and rescuers regarding these issues should be pursued. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  16. Estimating the spatial and temporal distribution of species richness within Sequoia and Kings Canyon National Parks.

    Directory of Open Access Journals (Sweden)

    Steve Wathen

    Full Text Available Evidence for significant losses of species richness or biodiversity, even within protected natural areas, is mounting. Managers are increasingly being asked to monitor biodiversity, yet estimating biodiversity is often prohibitively expensive. As a cost-effective option, we estimated the spatial and temporal distribution of species richness for four taxonomic groups (birds, mammals, herpetofauna (reptiles and amphibians, and plants within Sequoia and Kings Canyon National Parks using only existing biological studies undertaken within the Parks and the Parks' long-term wildlife observation database. We used a rarefaction approach to model species richness for the four taxonomic groups and analyzed those groups by habitat type, elevation zone, and time period. We then mapped the spatial distributions of species richness values for the four taxonomic groups, as well as total species richness, for the Parks. We also estimated changes in species richness for birds, mammals, and herpetofauna since 1980. The modeled patterns of species richness either peaked at mid elevations (mammals, plants, and total species richness or declined consistently with increasing elevation (herpetofauna and birds. Plants reached maximum species richness values at much higher elevations than did vertebrate taxa, and non-flying mammals reached maximum species richness values at higher elevations than did birds. Alpine plant communities, including sagebrush, had higher species richness values than did subalpine plant communities located below them in elevation. These results are supported by other papers published in the scientific literature. Perhaps reflecting climate change: birds and herpetofauna displayed declines in species richness since 1980 at low and middle elevations and mammals displayed declines in species richness since 1980 at all elevations.

  17. Flowering Trees

    Indian Academy of Sciences (India)

    Flowering Trees. Boswellia serrata Roxb. ex Colebr. (Indian Frankincense tree) of Burseraceae is a large-sized deciduous tree that is native to India. Bark is thin, greenish-ash-coloured that exfoliates into smooth papery flakes. Stem exudes pinkish resin ... Fruit is a three-valved capsule. A green gum-resin exudes from the ...

  18. Flowering Trees

    Indian Academy of Sciences (India)

    IAS Admin

    Flowering Trees. Ailanthus excelsa Roxb. (INDIAN TREE OF. HEAVEN) of Simaroubaceae is a lofty tree with large pinnately compound alternate leaves, which are ... inflorescences, unisexual and greenish-yellow. Fruits are winged, wings many-nerved. Wood is used in making match sticks. 1. Male flower; 2. Female flower.

  19. Flowering Trees

    Indian Academy of Sciences (India)

    Flowering Trees. Gyrocarpus americanus Jacq. (Helicopter Tree) of Hernandiaceae is a moderate size deciduous tree that grows to about 12 m in height with a smooth, shining, greenish-white bark. The leaves are ovate, rarely irregularly ... flowers which are unpleasant smelling. Fruit is a woody nut with two long thin wings.

  20. Flowering Trees

    Indian Academy of Sciences (India)

    More Details Fulltext PDF. Volume 8 Issue 8 August 2003 pp 112-112 Flowering Trees. Zizyphus jujuba Lam. of Rhamnaceae · More Details Fulltext PDF. Volume 8 Issue 9 September 2003 pp 97-97 Flowering Trees. Moringa oleifera · More Details Fulltext PDF. Volume 8 Issue 10 October 2003 pp 100-100 Flowering Trees.

  1. Mersin-Aydıncık İlçesi Anıt Dallı Servileri (Cupressus sempervirens L. var. horizontalis (Mill. Gord.

    Directory of Open Access Journals (Sweden)

    R. ÖZÇELİK

    2009-04-01

    Full Text Available Ülkemizde bugüne kadar bir çok anıt ağaç ve meşcerenin tespiti yapılmıştır. Bu çalışmada, Mersin ili Aydıncık İlçesindeki; çap, boy, yaş, tepe çapı (somut özellikler ve Mistik özellikleri (soyut özellikler nedeniyle anıt ağaç niteliği taşıyan iki adet Dallı Servi (Cupresus sempervirens L. var. horizontalis (Mill. Gord. tanıtılmıştır. Bu iki ağaç, şimdiye kadar anıt ağaç olarak tescili yapılmış en uzun boylu servi bireyleridir. Bu nedenle; doğal, kültürel ve estetik değere sahip bu doğal varlıkların korunması gerekmektedir.

  2. Determination of epigenetic inheritance, genetic inheritance, and estimation of genome DNA methylation in a full-sib family of Cupressus sempervirens L.

    Science.gov (United States)

    Avramidou, Evangelia V; Doulis, Andreas G; Aravanopoulos, Filippos A

    2015-05-15

    Genetic inheritance and epigenetic inheritance are significant determinants of plant evolution, adaptation and plasticity. We studied inheritance of restriction site polymorphisms by the f-AFLP method and epigenetic DNA cytosine methylation inheritance by the f-MSAP technique. The study involved parents and 190 progeny of a Cupressus sempervirens L. full-sib family. Results from AFLP genetic data revealed that 71.8% of the fragments studied are under Mendelian genetic control, whereas faithful Mendelian inheritance for the MSAP fragments was low (4.29%). Further, MSAP fragment analysis showed that total methylation presented a mean of 28.2%, which was higher than the midparent value, while maternal inheritance was higher (5.65%) than paternal (3.01%). Interestingly de novo methylation in the progeny was high (19.65%) compared to parental methylation. Genetic and epigenetic distances for parents and offspring were not correlated (R(2)=0.0005). Furthermore, we studied correlation of total relative methylation and CG methylation with growth (height, diameter). We found CG/CNG methylation (N: A, C, T) to be positively correlated with height and diameter, while total relative methylation and CG methylation were positively correlated with height. Results are discussed in light of further research needed and of their potential application in breeding. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The loss of essential oil components induced by the Purge Time in the Pressurized Liquid Extraction (PLE) procedure of Cupressus sempervirens.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Czapczyńska, Natalia B; Wianowska, Dorota

    2012-05-30

    The influence of different Purge Times on the effectiveness of Pressurized Liquid Extraction (PLE) of volatile oil components from cypress plant matrix (Cupressus sempervirens) was investigated, applying solvents of diverse extraction efficiencies. The obtained results show the decrease of the mass yields of essential oil components as a result of increased Purge Time. The loss of extracted components depends on the extrahent type - the greatest mass yield loss occurred in the case of non-polar solvents, whereas the smallest was found in polar extracts. Comparisons of the PLE method with Sea Sand Disruption Method (SSDM), Matrix Solid-Phase Dispersion Method (MSPD) and Steam Distillation (SD) were performed to assess the method's accuracy. Independent of the solvent and Purge Time applied in the PLE process, the total mass yield was lower than the one obtained for simple, short and relatively cheap low-temperature matrix disruption procedures - MSPD and SSDM. Thus, in the case of volatile oils analysis, the application of these methods is advisable. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. 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...

  5. 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...

  6. Attività sperimentale di agricoltura di precisione su vigneto Confronto tra i sensori Mapir Survey2 e Parrot Sequoia

    Directory of Open Access Journals (Sweden)

    Simone Kartsiotis

    2018-01-01

    Full Text Available This report presents a comparison via field-testing between Parrot Sequoia and Mapir Survey2 multispectral cameras. Both sensors are commonly used in precision farming activities conducted by micro-RPAS (drones, thanks to their small size and light weight. The experimental activity was performed in summer on the vineyards of the Savignola Paolina agricultural holding in Tuscany. The sensors were taken on board the EXOS drone, a hexacopter developed by Zephyr S.r.l. company and specifically designed for precision farming operations. Good and bad qualities for each cameras are examined by a comprehensive approach, starting from technical specifications and continuing with a comparison of the results obtained on field. All the activity was performed by a partnership between the companies DroneBee and Zephyr S.r.l. .

  7. Tree Nut Allergies

    Science.gov (United States)

    ... Blog Vision Awards Common Allergens Tree Nut Allergy Tree Nut Allergy Learn about tree nut allergy, how ... a Tree Nut Label card . Allergic Reactions to Tree Nuts Tree nuts can cause a severe and ...

  8. Extreme sensitivity of gene expression in human SH-SY5Y neurocytes to ultra-low doses of Gelsemium sempervirens

    Science.gov (United States)

    2014-01-01

    Background Gelsemium sempervirens L. (Gelsemium s.) is a traditional medicinal plant, employed as an anxiolytic at ultra-low doses and animal models recently confirmed this activity. However the mechanisms by which it might operate on the nervous system are largely unknown. This work investigates the gene expression of a human neurocyte cell line treated with increasing dilutions of Gelsemium s. extract. Methods Starting from the crude extract, six 100 × (centesimal, c) dilutions of Gelsemium s. (2c, 3c, 4c, 5c, 9c and 30c) were prepared according to the French homeopathic pharmacopoeia. Human SH-SY5Y neuroblastoma cells were exposed for 24 h to test dilutions, and their transcriptome compared by microarray to that of cells treated with control vehicle solutions. Results Exposure to the Gelsemium s. 2c dilution (the highest dose employed, corresponding to a gelsemine concentration of 6.5 × 10-9 M) significantly changed the expression of 56 genes, of which 49 were down-regulated and 7 were overexpressed. Several of the down-regulated genes belonged to G-protein coupled receptor signaling pathways, calcium homeostasis, inflammatory response and neuropeptide receptors. Fisher exact test, applied to the group of 49 genes down-regulated by Gelsemium s. 2c, showed that the direction of effects was significantly maintained across the treatment with high homeopathic dilutions, even though the size of the differences was distributed in a small range. Conclusions The study shows that Gelsemium s., a medicinal plant used in traditional remedies and homeopathy, modulates a series of genes involved in neuronal function. A small, but statistically significant, response was detected even to very low doses/high dilutions (up to 30c), indicating that the human neurocyte genome is extremely sensitive to this regulation. PMID:24642002

  9. Flowering Trees

    Indian Academy of Sciences (India)

    medium-sized handsome tree with a straight bole that branches at the top. Leaves are once pinnate, with two to three pairs of leaflets. Young parts of the tree are velvety. Inflorescence is a branched raceme borne at the branch ends. Flowers are large, white, attractive, and fragrant. Corolla is funnel-shaped. Fruit is an ...

  10. Flowering Trees

    Indian Academy of Sciences (India)

    Cassia siamia Lamk. (Siamese tree senna) of Caesalpiniaceae is a small or medium size handsome tree. Leaves are alternate, pinnately compound and glandular, upto 18 cm long with 8–12 pairs of leaflets. Inflorescence is axillary or terminal and branched. Flowering lasts for a long period from March to February. Fruit is ...

  11. Flowering Trees

    Indian Academy of Sciences (India)

    Flowering Trees. Cerbera manghasL. (SEA MANGO) of Apocynaceae is a medium-sized evergreen coastal tree with milky latex. The bark is grey-brown, thick and ... Fruit is large. (5–10 cm long), oval containing two flattened seeds and resembles a mango, hence the name Mangas or. Manghas. Leaves and fruits contain ...

  12. Flowering Trees

    Indian Academy of Sciences (India)

    user

    Flowering Trees. Gliricidia sepium(Jacq.) Kunta ex Walp. (Quickstick) of Fabaceae is a small deciduous tree with. Pinnately compound leaves. Flower are prroduced in large number in early summer on terminal racemes. They are attractive, pinkish-white and typically like bean flowers. Fruit is a few-seeded flat pod.

  13. Flowering Trees

    Indian Academy of Sciences (India)

    Flowering Trees. Acrocarpus fraxinifolius Wight & Arn. (PINK CEDAR, AUSTRALIAN ASH) of. Caesalpiniaceae is a lofty unarmed deciduous native tree that attains a height of 30–60m with buttresses. Bark is thin and light grey. Leaves are compound and bright red when young. Flowers in dense, erect, axillary racemes.

  14. 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…

  15. Drawing Trees

    DEFF Research Database (Denmark)

    Halkjær From, Andreas; Schlichtkrull, Anders; Villadsen, Jørgen

    2018-01-01

    We formally prove in Isabelle/HOL two properties of an algorithm for laying out trees visually. The first property states that removing layout annotations recovers the original tree. The second property states that nodes are placed at least a unit of distance apart. We have yet to formalize three...

  16. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    Grevillea robusta A. Cunn. ex R. Br. (Sil- ver Oak) of Proteaceae is a daintily lacy ornamental tree while young and growing into a mighty tree (45 m). Young shoots are silvery grey and the leaves are fern- like. Flowers are golden-yellow in one- sided racemes (10 cm). Fruit is a boat- shaped, woody follicle.

  17. Decomposition and N cycling changes in redwood forests caused by sudden oak death

    Science.gov (United States)

    Richard C. Cobb; David M. Rizzo

    2012-01-01

    Phytophthora ramorum is an emergent pathogen in redwood forests which causes the disease sudden oak death. Although the disease does not kill coast redwood (Sequoia sempervirens), extensive and rapid mortality of tanoak (Notholithocarpus densiflorus) has removed this...

  18. Phylogenetic trees

    OpenAIRE

    Baños, Hector; Bushek, Nathaniel; Davidson, Ruth; Gross, Elizabeth; Harris, Pamela E.; Krone, Robert; Long, Colby; Stewart, Allen; Walker, Robert

    2016-01-01

    We introduce the package PhylogeneticTrees for Macaulay2 which allows users to compute phylogenetic invariants for group-based tree models. We provide some background information on phylogenetic algebraic geometry and show how the package PhylogeneticTrees can be used to calculate a generating set for a phylogenetic ideal as well as a lower bound for its dimension. Finally, we show how methods within the package can be used to compute a generating set for the join of any two ideals.

  19. Tree thermometers and commodities: historic climate indicators

    International Nuclear Information System (INIS)

    Libby, L.M.; Pandolfi, L.J.

    1979-01-01

    In four modern trees, hydrogen and oxygen isotope ratios track the modern temperature records. In a 2000-yr sequence of a Japanese cedar, there are the same periodicities of variation of D/H and O 18 /O 16 as have been found in O 18 /O 16 in a Greenland ice well. The same periodicities are found in uranium and organic carbon concentrations versus depth in a sea core from the Santa Barbara Channel, and in carbon-14 variations in a sequence of Bristlecone pine from southern California. In a 2000-yr sequence of Japanese cedar and in a 1000-yr sequence of European oak D/H and O 18 /O 16 are related to each other by a slope of 8, just as they are in world-wide precipitation. In a 72-yr sequence of Sequoia gigantea, measured year by year for its oxygen isotope ratios, the 10.5-yr cycle of sunspot numbers found, but not the 21-yr cycle of sunspot magnetism; this we believe indicates that the sun is affecting the earth's climate with non-magnetic particles, probably photons. All these phenomena are related to periodic changes in sea surface temperature caused by periodic changes in the sun. (author)

  20. 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....

  1. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    shaped corolla. Fruit is large, ellipsoidal, green with a hard and smooth shell containing numerous flattened seeds, which are embedded in fleshy pulp. Calabash tree is commonly grown in the tropical gardens of the world as a botanical oddity.

  2. Instituto SEQUOIA : Um serviço privado,  multidisciplinar e de cuidado aos idosos SEQUOIA Institute: A multidisciplinary private service for the care of senior citizens L’Institut SEQUOIA : Un service privé multidisciplinaire pour les soins des personnes du troisième âge Instituto SEQUOIA : Un servicio privado y multidisciplinario de atención a las personas de la tercera edad

    Directory of Open Access Journals (Sweden)

    Anelise Fonseca

    2011-10-01

    Full Text Available Population aging is a reality all over the world, requiring a change in the way care is perceived and resources are divided for different age groups. In Brazil, current indicators and projections place the country among those with the highest number of elderly people. By contrast, there is a shortage of action plans and inter- and multi-disciplinary teams, as well as public policies and professionals, focusing on the elderly, in part as a consequence of an accelerated aging process in developing countries. Within this context, the SEQUOIA Institute (IS was created to attend to this process by monitoring the overall health of patients. The institute's routine work includes clinical actions, team meetings, socialization projects and lectures. The IS features a 10% yearly growth in medical assistance, a 20% rise in psychological treatments, and a 50% increase in lecture attendance.Le vieillissement de la population est un phénomène mondial qui exige de revoir la façon dont sont perçus les soins et dont sont divisées les ressources en fonction des différentes tranches d’âge. Les indicateurs et les projections actuels montrent que le Brésil est le pays qui compte la plus grande proportion de personnes âgées. Et pourtant, les plans d’action, les équipes inter- et pluridisciplinaires, mais aussi les politiques publiques et les professionnels spécialistes des questions liées aux personnes âgées sont en nombre insuffisant, notamment en raison d’un processus de vieillissement accéléré dans les pays en développement. C’est dans ce contexte qu’a été créé l’Institut SEQUOIA (IS, dont la mission consiste à gérer ce processus en effectuant un suivi de la santé générale des patients. Les principales tâches de l’institut incluent études cliniques, réunions d’équipes, projets impliquant des débats et conférences. L’IS affiche une croissance annuelle de 10 % dans le secteur de l’assistance médicale, de 20

  3. Critical Loads of Atmospheric Nitrogen Deposition for Aquatic Ecosystems in Yosemite and Sequoia and Kings Canyon National Parks

    Science.gov (United States)

    Nanus, L.; Clow, D. W.; Sickman, J. O.

    2016-12-01

    High-elevation aquatic ecosystems in Yosemite (YOSE) and Sequoia and Kings Canyon (SEKI) National Parks are impacted by atmospheric nitrogen (N) deposition associated with local and regional air pollution. Documented effects include elevated surface water nitrate concentrations, increased algal productivity, and changes in diatom species assemblages. Annual wet inorganic N deposition maps, developed at 1-km resolution for YOSE and SEKI to quantify N deposition to sensitive high-elevation ecosystems, range from 1.0 to over 5.0 kg N ha-1 yr-1. Critical loads of N deposition for nutrient enrichment of aquatic ecosystems were quantified and mapped using a geostatistical approach, with N deposition, topography, vegetation, geology, and climate as potential explanatory variables. Multiple predictive models were created using various combinations of explanatory variables; this approach allowed us to better quantify uncertainty and more accurately identify the areas most sensitive to atmospherically deposited N. The lowest critical loads estimates and highest exceedances identified within YOSE and SEKI occurred in high-elevation basins with steep slopes, sparse vegetation, and areas of neoglacial till and talus. These results are consistent with previous analyses in the Rocky Mountains, and highlight the sensitivity of alpine ecosystems to atmospheric N deposition.

  4. SEQUOIA Institute: A multidisciplinary private service for the care of senior citizens L’Institut SEQUOIA : Un service privé multidisciplinaire pour les soins des personnes du troisième âge Instituto SEQUOIA : Un servicio privado y multidisciplinario de atención a las personas de la tercera edad

    Directory of Open Access Journals (Sweden)

    Anelise Fonseca

    2011-10-01

    Full Text Available Population aging is a reality all over the world, requiring a change in the way care is perceived and resources are divided for different age groups. In Brazil, current indicators and projections place the country among those with the highest number of elderly people. By contrast, there is a shortage of action plans and inter- and multi-disciplinary teams, as well as public policies and professionals, focusing on the elderly, in part as a consequence of an accelerated aging process in developing countries. Within this context, the SEQUOIA Institute (IS was created to attend to this process by monitoring the overall health of patients. The institute's routine work includes clinical actions, team meetings, socialization projects and lectures. The IS features a 10% yearly growth in medical assistance, a 20% rise in psychological treatments, and a 50% increase in lecture attendance.Le vieillissement de la population est un phénomène mondial qui exige de revoir la façon dont sont perçus les soins et dont sont divisées les ressources en fonction des différentes tranches d’âge. Les indicateurs et les projections actuels montrent que le Brésil est le pays qui compte la plus grande proportion de personnes âgées. Et pourtant, les plans d’action, les équipes inter- et pluridisciplinaires, mais aussi les politiques publiques et les professionnels spécialistes des questions liées aux personnes âgées sont en nombre insuffisant, notamment en raison d’un processus de vieillissement accéléré dans les pays en développement. C’est dans ce contexte qu’a été créé l’Institut SEQUOIA (IS, dont la mission consiste à gérer ce processus en effectuant un suivi de la santé générale des patients. Les principales tâches de l’institut incluent études cliniques, réunions d’équipes, projets impliquant des débats et conférences. L’IS affiche une croissance annuelle de 10 % dans le secteur de l’assistance médicale, de 20

  5. Flowering Trees

    Indian Academy of Sciences (India)

    deciduous tree with irregularly-shaped trunk, greyish-white scaly bark and milky latex. Leaves in opposite pairs are simple, oblong and whitish beneath. Flowers that occur in branched inflorescence are white, 2–. 3cm across and fragrant. Calyx is glandular inside. Petals bear numerous linear white scales, the corollary.

  6. Flowering Trees

    Indian Academy of Sciences (India)

    Berrya cordifolia (Willd.) Burret (Syn. B. ammonilla Roxb.) – Trincomali Wood of Tiliaceae is a tall evergreen tree with straight trunk, smooth brownish-grey bark and simple broad leaves. Inflorescence is much branched with white flowers. Stamens are many with golden yellow anthers. Fruit is a capsule with six spreading ...

  7. Flowering Trees

    Indian Academy of Sciences (India)

    Canthium parviflorum Lam. of Rubiaceae is a large shrub that often grows into a small tree with conspicuous spines. Leaves are simple, in pairs at each node and are shiny. Inflorescence is an axillary few-flowered cymose fascicle. Flowers are small (less than 1 cm across), 4-merous and greenish-white. Fruit is ellipsoid ...

  8. Flowering Trees

    Indian Academy of Sciences (India)

    sriranga

    Hook.f. ex Brandis (Yellow. Cadamba) of Rubiaceae is a large and handsome deciduous tree. Leaves are simple, large, orbicular, and drawn abruptly at the apex. Flowers are small, yellowish and aggregate into small spherical heads. The corolla is funnel-shaped with five stamens inserted at its mouth. Fruit is a capsule.

  9. Flowering Trees

    Indian Academy of Sciences (India)

    Celtis tetrandra Roxb. of Ulmaceae is a moderately large handsome deciduous tree with green branchlets and grayish-brown bark. Leaves are simple with three to four secondary veins running parallel to the mid vein. Flowers are solitary, male, female and bisexual and inconspicuous. Fruit is berry-like, small and globose ...

  10. Flowering Trees

    Indian Academy of Sciences (India)

    IAS Admin

    Aglaia elaeagnoidea (A.Juss.) Benth. of Meliaceae is a small-sized evergreen tree of both moist and dry deciduous forests. The leaves are alternate and pinnately compound, terminating in a single leaflet. Leaflets are more or less elliptic with entire margin. Flowers are small on branched inflorescence. Fruit is a globose ...

  11. Flowering Trees

    Indian Academy of Sciences (India)

    user

    Flowers are borne on stiff bunches terminally on short shoots. They are 2-3 cm across, white, sweet-scented with light-brown hairy sepals and many stamens. Loquat fruits are round or pear-shaped, 3-5 cm long and are edible. A native of China, Loquat tree is grown in parks as an ornamental and also for its fruits.

  12. Flowering Trees

    Indian Academy of Sciences (India)

    mid-sized slow-growing evergreen tree with spreading branches that form a dense crown. The bark is smooth, thick, dark and flakes off in large shreds. Leaves are thick, oblong, leathery and bright red when young. The female flowers are drooping and are larger than male flowers. Fruit is large, red in color and velvety.

  13. Flowering Trees

    Indian Academy of Sciences (India)

    Andira inermis (wright) DC. , Dog Almond of Fabaceae is a handsome lofty evergreen tree. Leaves are alternate and pinnately compound with 4–7 pairs of leaflets. Flowers are fragrant and are borne on compact branched inflorescences. Fruit is ellipsoidal one-seeded drupe that is peculiar to members of this family.

  14. Flowering Trees

    Indian Academy of Sciences (India)

    narrow towards base. Flowers are large and attrac- tive, but emit unpleasant foetid smell. They appear in small numbers on erect terminal clusters and open at night. Stamens are numerous, pink or white. Style is slender and long, terminating in a small stigma. Fruit is green, ovoid and indistinctly lobed. Flowering Trees.

  15. Flowering Trees

    Indian Academy of Sciences (India)

    Muntingia calabura L. (Singapore cherry) of. Elaeocarpaceae is a medium size handsome ever- green tree. Leaves are simple and alternate with sticky hairs. Flowers are bisexual, bear numerous stamens, white in colour and arise in the leaf axils. Fruit is a berry, edible with several small seeds embedded in a fleshy pulp ...

  16. ~{owering 'Trees

    Indian Academy of Sciences (India)

    . Stamens are fused into a purple staminal tube that is toothed. Fruit is about 0.5 in. across, nearly globose, generally 5-seeded, green but yellow when ripe, quite smooth at first but wrinkled in drying, remaining long on the tree ajier ripening.

  17. Tree Mortality

    Science.gov (United States)

    Mark J. Ambrose

    2012-01-01

    Tree mortality is a natural process in all forest ecosystems. However, extremely high mortality also can be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

  18. Flowering Trees

    Indian Academy of Sciences (India)

    Guaiacum officinale L. (LIGNUM-VITAE) of Zygophyllaceae is a dense-crowned, squat, knobbly, rough and twisted medium-sized ev- ergreen tree with mottled bark. The wood is very hard and resinous. Leaves are compound. The leaflets are smooth, leathery, ovate-ellipti- cal and appear in two pairs. Flowers (about 1.5.

  19. The effect of low- and high-power microwave irradiation on in vitro grown Sequoia plants and their recovery after cryostorage.

    Science.gov (United States)

    Halmagyi, A; Surducan, E; Surducan, V

    2017-09-01

    Two distinct microwave power levels and techniques have been studied in two cases: low-power microwave (LPM) irradiation on in vitro Sequoia plants and high-power microwave (HPM) exposure on recovery rates of cryostored (-196°C) Sequoia shoot apices. Experimental variants for LPM exposure included: (a) in vitro plants grown in regular conditions (at 24 ± 1°C during a 16-h light photoperiod with a light intensity of 39.06 μEm -2 s -1 photosynthetically active radiation), (b) in vitro plants grown in the anechoic chamber with controlled environment without microwave irradiation, and (c) in vitro plants grown in the anechoic chamber with LPM irradiation for various times (5, 15, 30, 40 days). In comparison to control plants, significant differences in shoot multiplication and growth parameters (length of shoots and roots) were observed after 40 days of LPM exposure. An opposite effect was achieved regarding the content of total soluble proteins, which decreased with increasing exposure time to LPM. HPM irradiation was tested as a novel rewarming method following storage in liquid nitrogen. To our knowledge, this is the first report using this type of rewarming method. Although, shoot tips subjected to HPM exposure showed 28% recovery following cryostorage compared to 44% for shoot tips rewarmed in liquid medium at 22 ± 1 °C, we consider that the method represent a basis and can be further improved. The results lead to the overall conclusion that LPM had a stimulating effect on growth and multiplication of in vitro Sequoia plants, while the HPM used for rewarming of cryopreserved apices was not effective to achieve high rates of regrowth after liquid nitrogen exposure.

  20. Effects of stock use and backpackers on water quality in wilderness in Sequoia and Kings Canyon National Parks, USA

    Science.gov (United States)

    Clow, David W.; Forrester, Harrison; Miller, Benjamin; Roop, Heidi; Sickman, James O.; Ryu, Hodon; Santo Domingo, Jorge

    2013-01-01

    During 2010-2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water-quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water-quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli (E. coli) concentrations. The synoptic survey sites were categorized as minimal use, backpacker use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E.coli) than those categorized as minimal-use (p≤0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E.coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas (p≤0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E.coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.

  1. Surface tree languages and parallel derivation trees

    NARCIS (Netherlands)

    Engelfriet, Joost

    1976-01-01

    The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems. The corresponding class of tree transformation languages is therefore equal to the class of ETOL languages.

  2. Trees are good, but…

    Science.gov (United States)

    E.G. McPherson; F. Ferrini

    2010-01-01

    We know that “trees are good,” and most people believe this to be true. But if this is so, why are so many trees neglected, and so many tree wells empty? An individual’s attitude toward trees may result from their firsthand encounters with specific trees. Understanding how attitudes about trees are shaped, particularly aversion to trees, is critical to the business of...

  3. 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...

  4. Simple street tree sampling

    Science.gov (United States)

    David J. Nowak; Jeffrey T. Walton; James Baldwin; Jerry. Bond

    2015-01-01

    Information on street trees is critical for management of this important resource. Sampling of street tree populations provides an efficient means to obtain street tree population information. Long-term repeat measures of street tree samples supply additional information on street tree changes and can be used to report damages from catastrophic events. Analyses of...

  5. An individual-based growth and competition model for coastal redwood forest restoration

    Science.gov (United States)

    van Mantgem, Phillip J.; Das, Adrian J.

    2014-01-01

    Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying mechanisms governing how individual tree growth responds to competitive environments in coastal redwood forests. We created a spatially explicit individual-based model of tree competition and growth parameterized using surveys of upland redwood forests at Redwood National Park, California. We modeled competition for overstory trees (stems ≥ 20 cm stem diameter at breast height, 1.37 m (dbh)) as growth reductions arising from sizes, distances, and species identity of competitor trees. Our model explained up to half of the variation in individual tree growth, suggesting that neighborhood crowding is an important determinant of growth in this forest type. We used our model to simulate the effects of novel thinning prescriptions (e.g., 40% stand basal area removal) for redwood forest restoration, concluding that these treatments could lead to substantial growth releases, particularly for S. sempervirens. The results of this study, along with continued improvements to our model, will help to determine spacing and species composition that best encourage growth.

  6. City of Pittsburgh Trees

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Trees cared for and managed by the City of Pittsburgh Department of Public Works Forestry Division. Tree Benefits are calculated using the National Tree Benefit...

  7. Planting sentinel European trees in eastern Asia as a novel method to identify potential insect pest invaders.

    Science.gov (United States)

    Roques, Alain; Fan, Jian-Ting; Courtial, Béatrice; Zhang, Yan-Zhuo; Yart, Annie; Auger-Rozenberg, Marie-Anne; Denux, Olivier; Kenis, Marc; Baker, Richard; Sun, Jiang-Hua

    2015-01-01

    Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This

  8. Impacts of floods on forest trees and their coping strategies in Bangladesh

    Directory of Open Access Journals (Sweden)

    Shukla Rani Basak

    2015-03-01

    Full Text Available During recent years, the Government of Bangladesh, Non-Government Organizations (NGOs, semi-government organizations, private organizations and individuals have established a large number of plantations under different programs viz. social forestry, agro-forestry and avenue plantations with indigenous and exotic tree species without considering their habit and habitats. Along with the indigenous species like Albizia procera, Albizia lebbeck, Mangifera indica, Azadirachta indica, Gmelina arborea, Trewia nudiflora and Artocapus heterophyllus and many exotic species e.g. Swietenia macrophylla, Albizia saman, Dalbergia sissoo, Eucalyptus camaldulensis, Acacia auriculiformis, Melia sempervirens, Acacia mangium etc. have been planted randomly. With increasing trend of climate-induced floods, millions of trees have been dying due to floods and water-logging. The most affected species are Dalbergia sissoo, Albizia saman, Acacia auriculiformis, Acacia mangium and Artocarpus heterophyllus etc. This situation has caused severe impacts on socio-economic conditions of Bangladesh. The impacts involved a significant loss in terms of investment, biodiversity and afforestation program. Little investigations have been conducted to find out the causes of the deaths and also to find out the suitable adaptation practices to reduce impacts of floods on trees. This synthesis focused on the impacts of floods on plantations and also assessed the potential role of traditional forest management practices in addressing the effects flooding on forests in Bangladesh. The study added important information and revealed knowledge gaps on the causes of large forest deaths. It also provided recommendations for policy on the establishment of frequent floods resilient tree crop plantations.

  9. Categorizing ideas about trees: a tree of trees.

    Science.gov (United States)

    Fisler, Marie; Lecointre, Guillaume

    2013-01-01

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

  10. Urban tree growth modeling

    Science.gov (United States)

    E. Gregory McPherson; Paula J. Peper

    2012-01-01

    This paper describes three long-term tree growth studies conducted to evaluate tree performance because repeated measurements of the same trees produce critical data for growth model calibration and validation. Several empirical and process-based approaches to modeling tree growth are reviewed. Modeling is more advanced in the fields of forestry and...

  11. Keeping trees as assets

    Science.gov (United States)

    Kevin T. Smith

    2009-01-01

    Landscape trees have real value and contribute to making livable communities. Making the most of that value requires providing trees with the proper care and attention. As potentially large and long-lived organisms, trees benefit from commitment to regular care that respects the natural tree system. This system captures, transforms, and uses energy to survive, grow,...

  12. Classification and regression trees

    CERN Document Server

    Breiman, Leo; Olshen, Richard A; Stone, Charles J

    1984-01-01

    The methodology used to construct tree structured rules is the focus of this monograph. Unlike many other statistical procedures, which moved from pencil and paper to calculators, this text's use of trees was unthinkable before computers. Both the practical and theoretical sides have been developed in the authors' study of tree methods. Classification and Regression Trees reflects these two sides, covering the use of trees as a data analysis method, and in a more mathematical framework, proving some of their fundamental properties.

  13. Fault tree handbook

    International Nuclear Information System (INIS)

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

    1981-01-01

    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

  14. There's Life in Hazard Trees

    Science.gov (United States)

    Mary Torsello; Toni McLellan

    The goals of hazard tree management programs are to maximize public safety and maintain a healthy sustainable tree resource. Although hazard tree management frequently targets removal of trees or parts of trees that attract wildlife, it can take into account a diversity of tree values. With just a little extra planning, hazard tree management can be highly beneficial...

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

    Science.gov (United States)

    Qasem, Jamal R

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jamal R. Qasem

    2012-01-01

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

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

    Science.gov (United States)

    Qasem, Jamal R.

    2012-01-01

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

  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. Trees and highway safety.

    Science.gov (United States)

    2011-03-01

    To minimize the severity of run-off-road collisions of vehicles with trees, departments of transportation (DOTs) : commonly establish clear zones for trees and other fixed objects. Caltrans clear zone on freeways is 30 feet : minimum (40 feet pref...

  20. Functional Ecology Effect Aspect Geographic on the Cypress (Cupresuss sempervirens L.var horizontalis) Growth in the Abbas Abad Behshahr Planting Stand

    International Nuclear Information System (INIS)

    Kalantari, H.; Fallah, A.; Hojjati, M.

    2016-01-01

    Background and Objective: To evaluate the growth of cypress in different aspects (North West, West, Northeast and Southwest) is a pure planting stand in the area of Abbas Abad Behshar was considered. Method: Using the inventory network 75 × 100 m and a stratified random method, 50 samples plot 2 R (200 square meters) in different geographical aspects was carried out. In each sample plots, diameters and height of four trees were measured. Excel and SPSS statistical software and statistical analyses and necessary calculations were performed. Findings: The results showed that there are significant differences between amplitude with different aspects of growth. So that the highest diameter increment in the West aspect (0.53 cm) and the lowest in the North East aspect (0.479 cm) were observed. The maximum height growth in the West and South-West aspects (0.53 m) and the lowest was in the northwest aspect (0.49 m) and for average basal area growth, the highest growth in the West aspect was 0.87 m square per ha and lowest in the North west aspect was 0.76 square meters per hectare respectively. The average volume growth to age, respectively, in the aspect of West aspect (4 sylve per ha) and Northeast aspect (6.3 sylve per hectare) were the highest and lowest values.

  1. Decision-Tree Program

    Science.gov (United States)

    Buntine, Wray

    1994-01-01

    IND computer program introduces Bayesian and Markov/maximum-likelihood (MML) methods and more-sophisticated methods of searching in growing trees. Produces more-accurate class-probability estimates important in applications like diagnosis. Provides range of features and styles with convenience for casual user, fine-tuning for advanced user or for those interested in research. Consists of four basic kinds of routines: data-manipulation, tree-generation, tree-testing, and tree-display. Written in C language.

  2. Minnesota's Forest Trees. Revised.

    Science.gov (United States)

    Miles, William R.; Fuller, Bruce L.

    This bulletin describes 46 of the more common trees found in Minnesota's forests and windbreaks. The bulletin contains two tree keys, a summer key and a winter key, to help the reader identify these trees. Besides the two keys, the bulletin includes an introduction, instructions for key use, illustrations of leaf characteristics and twig…

  3. 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...

  4. 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 ...

  5. 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…

  6. 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....

  7. TreePics: visualizing trees with pictures

    Directory of Open Access Journals (Sweden)

    Nicolas Puillandre

    2017-09-01

    Full Text Available While many programs are available to edit phylogenetic trees, associating pictures with branch tips in an efficient and automatic way is not an available option. Here, we present TreePics, a standalone software that uses a web browser to visualize phylogenetic trees in Newick format and that associates pictures (typically, pictures of the voucher specimens to the tip of each branch. Pictures are visualized as thumbnails and can be enlarged by a mouse rollover. Further, several pictures can be selected and displayed in a separate window for visual comparison. TreePics works either online or in a full standalone version, where it can display trees with several thousands of pictures (depending on the memory available. We argue that TreePics can be particularly useful in a preliminary stage of research, such as to quickly detect conflicts between a DNA-based phylogenetic tree and morphological variation, that may be due to contamination that needs to be removed prior to final analyses, or the presence of species complexes.

  8. Box Tree Moth (Cydalima perspectalis, Lepidoptera; Crambidae, New Invasive Insect Pest in Croatia

    Directory of Open Access Journals (Sweden)

    Dinka Matošević

    2013-12-01

    Full Text Available Background and Purpose: Alien invasive species have been described as an outstanding global problem. Hundreds of species are intentionally and unintentionally moved worldwide and and numbers of introductions to new habitats have been accelerated all over the world due to the increasing mobility of people and goods over the past decades. Numerous alien insect species, many of them introduced only in the last 20 years, have become successfully established in various ecosystems in Croatia. Box tree moth (Cydalima perspectalis, Lepidoptera; Crambidae is an invasive pest recently introduced to Europe causing serious damage to ornamental box (Buxus sp. shrubs and trees. The aim of this paper is to describe the biology of box tree moth with prognosis of its future spread and damages in Croatia. Material and Methods: Young larvae (first and second larval stage and adults of box tree moth were collected in August and September 2013 in Arboretum Opeka and in Varaždin. They were brought to the entomological laboratory of Croatian Forest Research Institute where they were reared to pupae and then to moths. Results and Conclusions: The box tree moth was recorded for the first time in North Croatia in August 2013. Larvae were found defoliating box plants (B. sempervirens in Arboretum Opeka, Vinica and they have been identified as C. prespectalis. According to damages it can be assumed that the pest has been introduced to the region earlier (in 2011 or 2012 and that the primary infection has not been detected. At least two generations per year could be assumed in Croatia in 2013. The damage done to box tree plants on the locality of study is serious. The plants have been defoliated, particularly in the lower parts. The defoliation reduced the amenity value of plants. This is the first record of this pest and its damages in Northern Croatia and it can be expected that the pest will rapidly spread to other parts of Croatia seriously damaging box plants

  9. Spectra of chemical trees

    International Nuclear Information System (INIS)

    Balasubramanian, K.

    1982-01-01

    A method is developed for obtaining the spectra of trees of NMR and chemical interests. The characteristic polynomials of branched trees can be obtained in terms of the characteristic polynomials of unbranched trees and branches by pruning the tree at the joints. The unbranched trees can also be broken down further until a tree containing just two vertices is obtained. The effectively reduces the order of the secular determinant of the tree used at the beginning to determinants of orders atmost equal to the number of vertices in the branch containing the largest number of vertices. An illustrative example of a NMR graph is given for which the 22 x 22 secular determinant is reduced to determinants of orders atmost 4 x 4 in just the second step of the algorithm. The tree pruning algorithm can be applied even to trees with no symmetry elements and such a factoring can be achieved. Methods developed here can be elegantly used to find if two trees are cospectral and to construct cospectral trees

  10. Refining discordant gene trees.

    Science.gov (United States)

    Górecki, Pawel; Eulenstein, Oliver

    2014-01-01

    Evolutionary studies are complicated by discordance between gene trees and the species tree in which they evolved. Dealing with discordant trees often relies on comparison costs between gene and species trees, including the well-established Robinson-Foulds, gene duplication, and deep coalescence costs. While these costs have provided credible results for binary rooted gene trees, corresponding cost definitions for non-binary unrooted gene trees, which are frequently occurring in practice, are challenged by biological realism. We propose a natural extension of the well-established costs for comparing unrooted and non-binary gene trees with rooted binary species trees using a binary refinement model. For the duplication cost we describe an efficient algorithm that is based on a linear time reduction and also computes an optimal rooted binary refinement of the given gene tree. Finally, we show that similar reductions lead to solutions for computing the deep coalescence and the Robinson-Foulds costs. Our binary refinement of Robinson-Foulds, gene duplication, and deep coalescence costs for unrooted and non-binary gene trees together with the linear time reductions provided here for computing these costs significantly extends the range of trees that can be incorporated into approaches dealing with discordance.

  11. 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.

  12. 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...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...

  13. Morocco - Fruit Tree Productivity

    Data.gov (United States)

    Millennium Challenge Corporation — Date Tree Irrigation Project: The specific objectives of this evaluation are threefold: - Performance evaluation of project activities, like the mid-term evaluation,...

  14. [Analysis of the effectiveness of the spa and health resort-based treatment of the patients presenting with broncho-pulmonary pathology at the southern coast of the Crimea depending on the period of flowering of Mediterranean Cypress (Cupressus sempervirens)].

    Science.gov (United States)

    Savchenko, V M; Belyaeva, S N; Govorun, M I; Pirogova, M E

    The objective of the present study was to evaluate the influence of pollen of Mediterranean Cypress (Cupressus sempervirens) on the effectiveness of the spa and health resort-based treatment (SHRT) of the patients with broncho-pulmonary pathology at the southern coast of the Crimea (SCC). This article presents the results of the analysis of the data on 122 patients presenting with broncho-pulmonary pathology who received SHRT under the conditions of the Southern Coast of the Crimea. Fifty one (41.8%) of these patients suffered from chronic obstructive pulmonary disease and 71 (58.2%) ones had bronchial asthma. The whole group was comprised of 44 men (36.1%) and 78 women (63.9%). The average (median) age of the patients was 55.8 years. All the participants of the study underwent the comprehensive examination including the general medical and physical examination, complete blood count, the study of sputum cytology and immunological properties of blood including the standard characteristics, IgE and lysozyme levels), evaluation of the respiratory and locomotor (physical) functions with the use of the 6-minute walking test. The aeropollenological study of the aerial environment of the southern coast of the Crimea in the region of Yalta showed that the «bloom» of the Mediterranean Cypress occurs during the period from February till April inclusive. The highest concentrations of cypress pollen are observed in March and early April. The overall effectiveness of SHRT for the patients with broncho-pulmonary pathology arriving for the treatment at the southern coast of the Crimea from other Crimean localities does not depend on the period of «flowering» (the presence of pollen in the air) of the Mediterranean Cypress. In these patients, the termination of the spa and health resort-based treatment during the «flowering» of the Mediterranean Cypress resulted in nothing more than a strained adaptive response manifested as the altered blood leukocyte count. Such reaction

  15. Are trees long-lived?

    Science.gov (United States)

    Kevin T. Smith

    2009-01-01

    Trees and tree care can capture the best of people's motivations and intentions. Trees are living memorials that help communities heal at sites of national tragedy, such as Oklahoma City and the World Trade Center. We mark the places of important historical events by the trees that grew nearby even if the original tree, such as the Charter Oak in Connecticut or...

  16. Assessing the response of Emerald Lake, an alpine watershed in Sequoia National Park, California, to acidification during snowmelt by using a simple hydrochemical model

    International Nuclear Information System (INIS)

    Hooper, R.P.; West, C.T.; Peters, N.E.

    1990-01-01

    A sparsely parameterized hydrochemical model has been developed by using data from Emerald Lake watershed, which is a 120-ha alpine catchment in Sequoia National Park, California. Greater than 90% of the precipitation to this watershed is snow; hence, snowmelt is the dominant hydrologic event. A model which uses a single alkalinity-generating mechanism, primary mineral weathering, was able to capture the pattern of solute concentrations in surface waters during snowmelt. An empirical representation of the weathering reaction, which is based on rock weathering stoichiometry and which uses discharge as a measure of residence time, was included in the model. Results of the model indicate that current deposition levels would have to be increased between three-fold and eight-fold to exhaust the alkalinity of the lake during snowmelt if their is a mild acidic pulse in the stream at the beginning of snowmelt as was observed during the study period. The acidic pulse in the inflow stream at the onset of snowmelt was less pronounced than acidic pulses observed in the meltwater draining the snowpack at a point using snow lysimeters or in the laboratory. Sulfate concentrations in the stream water were the most constant; chloride and nitrate concentrations increased slightly at the beginning of snowmelt. Additional field work is required to resolve whether an acidic meltwater pulse occurs over a large area as well as at a point or whether, due to physical and chemical processes within the snowpack, the acidic meltwater pulse is attenuated at the catchment scale. The modest data requirements of the model permit its applications to other alpine watersheds that are much less intensively studied than Emerald Lake watershed

  17. Utilizing Remote Sensing Information to Improve Post-fire Rainfall-runoff Predictions after the 2010 Bull Fire in the Sequoia National Forest, CA

    Science.gov (United States)

    Kinoshita, A. M.; Hale, B.; Hogue, T. S.

    2012-12-01

    Post-fire management decisions are guided by rainfall-runoff predictions, which ultimately influence downstream treatment and mitigation costs. The current study investigates evolving rainfall-runoff partitioning at the watershed scale over a two-year period after the 2010 Bull Fire which occurred in the southern Sequoia National Forest in California. Stage height was measured at five-minute intervals using pressure transducers, tipping buckets were installed for rainfall duration and intensity, and channel cross-sections were measured approximately every two months to detail sediment deposition or scour. We also utilize remotely sensed vegetation data to evaluate vegetation recovery in the studied watersheds and the corresponding relationship to storm runoff. Normalized Difference Vegetation Index (NDVI), a measure of vegetation greenness, is evaluated for its potential use as a key recovery indicator. Preliminary results focus on alterations in annual and seasonal precipitation and discharge relationships using in-situ data and Landsat NDVI values for the period of study. NDVI values are consistent with a comprehensive burn, with an acute decrease observed in the initial post-fire period. However, vegetation recovery is highly variable in the studied systems and influenced by shorter-term biomass pulses (grasses) while longer-term recovery of other species (chaparral and pine) is ongoing. Runoff ratios are elevated during early storms and show some recovery in the later part of the study period. The ability to accurately and confidently predict post-fire runoff and longer-term recovery is critical for monitoring values-at-risk, reducing mitigation costs, and improving warnings to downstream public communities.

  18. Evaluating potential overlap between pack stock and Sierra Nevada bighorn sheep (Ovis canadensis sierrae) in Sequoia and Kings Canyon National Parks, California

    Science.gov (United States)

    Klinger, Robert C.; Few, Alexandra P.; Knox, Kathleen A.; Hatfield, Brian E.; Clark, Jonathan; German, David W.; Stephenson, Thomas R.

    2015-01-01

    Pack stock (horses, mules, burros, llamas, and goats) are frequently assumed to have negative effects on public lands, but there is a general lack of data to be able to quantify the degree to which this is actually the case. Sequoia and Kings Canyon National Parks have received complaints that pack stock may affect Sierra Nevada bighorn sheep (Ovis canadensis sierrae; SNBS), a federally endangered subspecies that occurs in largely disjunct herds in the Sierra Nevada Range of California. The potential effects are thought to be displacement of SNBS from meadows on their summer range (altered habitat use) or, more indirectly, through changes in SNBS habitat or forage quality. Our goals were to conduct an association analysis to quantify the degree of potential spatial overlap in meadow use between SNBS and pack stock and to compare differences in vegetation community composition, structure, and diversity among meadows with different levels of use by bighorn sheep and pack stock. For the association analysis, we used two approaches: (1) we quantified the proportion of meadows that were within the herd home ranges of bighorn sheep and were potentially open to pack stock, and, (2) we used Monte Carlo simulations and use-availability analyses to compare the proportion of meadows used by bighorn sheep relative to the proportional occurrence or area of meadows available to bighorn sheep that were used by pack stock. To evaluate potential effects of pack stock on meadow plant communities and SNBS forage, we sampled vegetation in 2011 and 2012 at 100 plots to generate data that allowed us to compare:

  19. Executive summary - Assessing the response of Emerald Lake, an alpine watershed in Sequoia National Park, California, to acidification during snowmelt using a simple hydrochemical model

    International Nuclear Information System (INIS)

    Hooper, R.P.; West, C.T.; Peters, N.E.

    1990-01-01

    A simple process-oriented model, called the Alpine Lake Forecaster (ALF), was constructed using data collected from the Integrated Watershed Study of Emerald Lake, Sequoia National Park, California. ALF is able to capture the basic solute patterns during snowmelt in this alpine catchment where groundwater is a minor contributor to streamflow. It includes an empirical representation of primary mineral weathering as the only alkalinity generating mechanism. During a heavy snow year, such as the one used for calibrating the model, the model accurately simulated the surface water chemical change in response to the initial ionic pulse from the snowpack and to the dilution that occurs at peak snowmelt. Because the model does not consider cation exchange, it over-predicts the acidification during the initial period of snowmelt, and therefore is a conservative predictor. However, the minimum alkalinity observed in the main inflows to Emerald Lake and in the lake outflow is accurately simulated by the model. The representation of the lake as simply a missing volume with no additional chemical reactions is supported by the observation. The model predicts a change of 2 to 5 microequiv/L in the minimum alkalinity of the lake outflow during snowmelt if the deposition would have to increase between two and 18 times the current load-alkalinity of the lake; the precise increase depends on hydrologic conditions and on the pattern of solute release from the snowpack. An acidic rainstorm that exhausted the alkalinity of the lake was observed during summer 1984 after the lake had stratified, and is the likely cause of the acidification of Emerald Lake

  20. Seasonal and diel environmental conditions predict western pond turtle (Emys marmorata) behavior at a perennial and an ephemeral stream in Sequoia National Park, California

    Science.gov (United States)

    Ruso, Gabrielle; Meyer, Erik; Das, Adrian J.

    2017-01-01

    Managers making decisions may benefit from a well-informed understanding of a species' population size and trends. Given the cryptic nature and habitat characteristics of the western pond turtle (Emys marmorata), however, imperfect detection may be high and population estimates are frequently varied and unreliable. As a case study to investigate this issue, we used temperature dataloggers to examine turtle behavior at 2 long-term monitoring sites with different hydrological characteristics in Sequoia National Park, California, to determine if common stream-survey techniques are consistent with site-specific turtle behavior. Sycamore Creek is an intermittent stream that dries up every summer while the North Fork Kaweah River flows year-round. We found that while turtles spent most of the recorded time in the water (55% in Sycamore Creek and 82% in the North Fork Kaweah River), the timing of traditional surveys only coincided with the turtles' aquatic activity in the North Fork Kaweah River. At Sycamore Creek, turtles were most likely to be in the water at night. In contrast, failure to detect turtles in North Fork Kaweah River is likely owing to the larger size and complexity of the underwater habitat. In both streams, turtles were also more likely to be in the water in the weeks leading up to important changes in hydroperiods. Our findings illustrate the effects that differences in water permanence can have on turtle behavior within the same watershed and how phenotypic plasticity may then affect detection during surveys. Our study highlights the importance of tailoring survey practices to the site-specific behavioral traits of the target species.

  1. Fragmentation of random trees

    International Nuclear Information System (INIS)

    Kalay, Z; Ben-Naim, E

    2015-01-01

    We study fragmentation of a random recursive tree into a forest by repeated removal of nodes. The initial tree consists of N nodes and it is generated by sequential addition of nodes with each new node attaching to a randomly-selected existing node. As nodes are removed from the tree, one at a time, the tree dissolves into an ensemble of separate trees, namely, a forest. We study statistical properties of trees and nodes in this heterogeneous forest, and find that the fraction of remaining nodes m characterizes the system in the limit N→∞. We obtain analytically the size density ϕ s of trees of size s. The size density has power-law tail ϕ s ∼s −α with exponent α=1+(1/m). Therefore, the tail becomes steeper as further nodes are removed, and the fragmentation process is unusual in that exponent α increases continuously with time. We also extend our analysis to the case where nodes are added as well as removed, and obtain the asymptotic size density for growing trees. (paper)

  2. The tree BVOC index

    Science.gov (United States)

    J.R. Simpson; E.G. McPherson

    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...

  3. Tree growth visualization

    Science.gov (United States)

    L. Linsen; B.J. Karis; E.G. McPherson; B. Hamann

    2005-01-01

    In computer graphics, models describing the fractal branching structure of trees typically exploit the modularity of tree structures. The models are based on local production rules, which are applied iteratively and simultaneously to create a complex branching system. The objective is to generate three-dimensional scenes of often many realistic- looking and non-...

  4. Flowering T Flowering Trees

    Indian Academy of Sciences (India)

    Adansonia digitata L. ( The Baobab Tree) of Bombacaceae is a tree with swollen trunk that attains a dia. of 10m. Leaves are digitately compound with leaflets up to 18cm. long. Flowers are large, solitary, waxy white, and open at dusk. They open in 30 seconds and are bat pollinated. Stamens are many. Fruit is about 30 cm ...

  5. Fault tree graphics

    International Nuclear Information System (INIS)

    Bass, L.; Wynholds, H.W.; Porterfield, W.R.

    1975-01-01

    Described is an operational system that enables the user, through an intelligent graphics terminal, to construct, modify, analyze, and store fault trees. With this system, complex engineering designs can be analyzed. This paper discusses the system and its capabilities. Included is a brief discussion of fault tree analysis, which represents an aspect of reliability and safety modeling

  6. Tree biology and dendrochemistry

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle

    1996-01-01

    Dendrochemistry, the interpretation of elemental analysis of dated tree rings, can provide a temporal record of environmental change. Using the dendrochemical record requires an understanding of tree biology. In this review, we pose four questions concerning assumptions that underlie recent dendrochemical research: 1) Does the chemical composition of the wood directly...

  7. Individual tree control

    Science.gov (United States)

    Harvey A. Holt

    1989-01-01

    Controlling individual unwanted trees in forest stands is a readily accepted method for improving the value of future harvests. The practice is especially important in mixed hardwood forests where species differ considerably in value and within species individual trees differ in quality. Individual stem control is a mechanical or chemical weeding operation that...

  8. Trees and Climate Change

    OpenAIRE

    Dettenmaier, Megan; Kuhns, Michael; Unger, Bethany; McAvoy, Darren

    2017-01-01

    This fact sheet describes the complex relationship between forests and climate change based on current research. It explains ways that trees can mitigate some of the risks associated with climate change. It details the impacts that forests are having on the changing climate and discuss specific ways that trees can be used to reduce or counter carbon emissions directly and indirectly.

  9. 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…

  10. 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...

  11. Environmental tritium in trees

    International Nuclear Information System (INIS)

    Brown, R.M.

    1979-01-01

    The distribution of environmental tritium in the free water and organically bound hydrogen of trees growing in the vicinity of the Chalk River Nuclear Laboratories (CRNL) has been studied. The regional dispersal of HTO in the atmosphere has been observed by surveying the tritium content of leaf moisture. Measurement of the distribution of organically bound tritium in the wood of tree ring sequences has given information on past concentrations of HTO taken up by trees growing in the CRNL Liquid Waste Disposal Area. For samples at background environmental levels, cellulose separation and analysis was done. The pattern of bomb tritium in precipitation of 1955-68 was observed to be preserved in the organically bound tritium of a tree ring sequence. Reactor tritium was discernible in a tree growing at a distance of 10 km from CRNL. These techniques provide convenient means of monitoring dispersal of HTO from nuclear facilities. (author)

  12. Generalising tree traversals and tree transformations to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2017-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal or a tree transformation and then apply it to compact graph representations of trees instead. The resul......We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal or a tree transformation and then apply it to compact graph representations of trees instead...... as the complementing theory with a number of examples....

  13. A recursive algorithm for trees and forests

    OpenAIRE

    Guo, Song; Guo, Victor J. W.

    2017-01-01

    Trees or rooted trees have been generously studied in the literature. A forest is a set of trees or rooted trees. Here we give recurrence relations between the number of some kind of rooted forest with $k$ roots and that with $k+1$ roots on $\\{1,2,\\ldots,n\\}$. Classical formulas for counting various trees such as rooted trees, bipartite trees, tripartite trees, plane trees, $k$-ary plane trees, $k$-edge colored trees follow immediately from our recursive relations.

  14. 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.

  15. 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...

  16. The gravity apple tree

    International Nuclear Information System (INIS)

    Aldama, Mariana Espinosa

    2015-01-01

    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. (paper)

  17. Visualizing phylogenetic tree landscapes.

    Science.gov (United States)

    Wilgenbusch, James C; Huang, Wen; Gallivan, Kyle A

    2017-02-02

    Genomic-scale sequence alignments are increasingly used to infer phylogenies in order to better understand the processes and patterns of evolution. Different partitions within these new alignments (e.g., genes, codon positions, and structural features) often favor hundreds if not thousands of competing phylogenies. Summarizing and comparing phylogenies obtained from multi-source data sets using current consensus tree methods discards valuable information and can disguise potential methodological problems. Discovery of efficient and accurate dimensionality reduction methods used to display at once in 2- or 3- dimensions the relationship among these competing phylogenies will help practitioners diagnose the limits of current evolutionary models and potential problems with phylogenetic reconstruction methods when analyzing large multi-source data sets. We introduce several dimensionality reduction methods to visualize in 2- and 3-dimensions the relationship among competing phylogenies obtained from gene partitions found in three mid- to large-size mitochondrial genome alignments. We test the performance of these dimensionality reduction methods by applying several goodness-of-fit measures. The intrinsic dimensionality of each data set is also estimated to determine whether projections in 2- and 3-dimensions can be expected to reveal meaningful relationships among trees from different data partitions. Several new approaches to aid in the comparison of different phylogenetic landscapes are presented. Curvilinear Components Analysis (CCA) and a stochastic gradient decent (SGD) optimization method give the best representation of the original tree-to-tree distance matrix for each of the three- mitochondrial genome alignments and greatly outperformed the method currently used to visualize tree landscapes. The CCA + SGD method converged at least as fast as previously applied methods for visualizing tree landscapes. We demonstrate for all three mtDNA alignments that 3D

  18. Planting sentinel European trees in eastern Asia as a novel method to identify potential insect pest invaders.

    Directory of Open Access Journals (Sweden)

    Alain Roques

    Full Text Available Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus and two conifer species (Abies alba and Cupressus sempervirens were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China, and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major

  19. 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

  20. Big trees, old trees, and growth factor tables

    Science.gov (United States)

    Kevin T. Smith

    2018-01-01

    The potential for a tree to reach a great size and to live a long life frequently captures the public's imagination. Sometimes the desire to know the age of an impressively large tree is simple curiosity. For others, the date-of-tree establishment can make a big diff erence for management, particularly for trees at historic sites or those mentioned in property...

  1. A bijection between phylogenetic trees and plane oriented recursive trees

    OpenAIRE

    Prodinger, Helmut

    2017-01-01

    Phylogenetic trees are binary nonplanar trees with labelled leaves, and plane oriented recursive trees are planar trees with an increasing labelling. Both families are enumerated by double factorials. A bijection is constructed, using the respective representations a 2-partitions and trapezoidal words.

  2. 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 r on n nodes and suffix links of its internal nodes, we ask the question “Is r a suffix tree?”, i.e., is there a string S whose suffix tree has the same topological structure as r? We place no restrictions on S, in part...

  3. 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...

  4. Trees for future forests

    DEFF Research Database (Denmark)

    Lobo, Albin

    Climate change creates new challenges in forest management. The increase in temperature may in the long run be beneficial for the forests in the northern latitudes, but the high rate at which climate change is predicted to proceed will make adaptation difficult because trees are long living sessile...... organisms. The aim of the present thesis is therefore to explore genetic resilience and phenotypic plasticity mechanisms that allows trees to adapt and evolve with changing climates. The thesis focus on the abiotic factors associated with climate change, especially raised temperatures and lack...... age of these tree species and the uncertainty around the pace and effect of climate, it remains an open question if the native populations can respond fast enough. Phenotypic plasticity through epigenetic regulation of spring phenology is found to be present in a tree species which might act...

  5. Value tree analysis

    International Nuclear Information System (INIS)

    Keeney, R.; Renn, O.; Winterfeldt, D. von; Kotte, U.

    1985-01-01

    What are the targets and criteria on which national energy policy should be based. What priorities should be set, and how can different social interests be matched. To answer these questions, a new instrument of decision theory is presented which has been applied with good results to controversial political issues in the USA. The new technique is known under the name of value tree analysis. Members of important West German organisations (BDI, VDI, RWE, the Catholic and Protestant Church, Deutscher Naturschutzring, and ecological research institutions) were asked about the goals of their organisations. These goals were then ordered systematically and arranged in a hierarchical tree structure. The value trees of different groups can be combined into a catalogue of social criteria of acceptability and policy assessment. The authors describe the philosophy and methodology of value tree analysis and give an outline of its application in the development of a socially acceptable energy policy. (orig.) [de

  6. 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 complexity...... of our algorithm only allows for the comparison of small trees, and that the results of our method are comparable with state-of-the-art using much fewer parameters for image representation....

  7. 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....

  8. 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

  9. Benefit-based tree valuation

    Science.gov (United States)

    E.G. McPherson

    2007-01-01

    Benefit-based tree valuation provides alternative estimates of the fair and reasonable value of trees while illustrating the relative contribution of different benefit types. This study compared estimates of tree value obtained using cost- and benefit-based approaches. The cost-based approach used the Council of Landscape and Tree Appraisers trunk formula method, and...

  10. Attack Trees with Sequential Conjunction

    NARCIS (Netherlands)

    Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

    2015-01-01

    We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

  11. Tree manipulation experiment

    Science.gov (United States)

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

    2012-12-01

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

  12. 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...

  13. Post-fire response of coast redwood one year after the Mendocino lightning complex fires

    Science.gov (United States)

    Robert B. Douglas; Tom. Bendurel

    2012-01-01

    Coast redwood (Sequoia sempervirens) forests have undergone significant changes over the past century and are now in state more conducive for wildfires. Because fires have been uncommon in redwood forests over the past 80 years, managers have limited data to make decisions about the post-fire environment. In June 2008, a series of lightning storms...

  14. Management practices eelated to the Restoration of old dorest characteristics in coast redwood forests

    Science.gov (United States)

    Gregory A. Guisti

    2012-01-01

    A standardized, interactive, interview process was used with practicing Registered Professional Foresters asking a suite of questions to ascertain their management approaches to coast redwood (Sequoia sempervirens [D. Don] Endl.) stands that could best be transferred to other projects and lands interested in recruiting older forest...

  15. A Multiple Logistic Regression Model for Predicting the Development of Phytophthora ramorum symptoms in Tanoak (Lithocarpus densiflorus)

    Science.gov (United States)

    Mark Spencer; Kevin O' Hara

    2007-01-01

    Phytophthora ramorum attacks tanoak (Lithocarpus densiflorus) in California and Oregon. We present a stand-level study examining the presence of disease symptoms in individual stems. Working with data from four plots in redwood (Sequoia sempervirens)/tanoak forests in Marin County, and three plots in Mendocino...

  16. Sudden Oak Death in redwood forests: vegetation dynamics in the wake of tanoak decline

    Science.gov (United States)

    Benjamin Ramage; Kevin O’Hara

    2010-01-01

    Numerous lines of inquiry have concluded that tanoak (Lithocarpus densiflorus) will continue to experience drastic population declines and may even disappear entirely from redwood (Sequoia sempervirens) forests as a result of the exotic disease sudden oak death (SOD) (Maloney and others 2005, McPherson and others 2005,...

  17. Biodegrading effects of some rot fungi on Pinus caribaea wood

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... species of white-rot fungi; Corioliopsis polyzona and Pleurotus squarrosulus, and two species of brown- rot fungi; Lentinus ... The results indicated that biodegradation by rot fungi differs in intensity according to the fungus ..... wood of coast red wood Sequoia Sempervirens (D. Don). For. Prod. J. 33(5): 15-20 ...

  18. Rangewide Genetic Variation in Coast Redwood Populations at a Chloroplast Microsatellite Locus

    Science.gov (United States)

    Chris Brinegar

    2012-01-01

    Old growth and second growth populations of coast redwood (Sequoia sempervirens) were sampled at 10 locations throughout its range and analyzed at a highly variable chloroplast microsatellite locus. Very low FST values indicated that there was no significant genetic differentiation between adjacent old growth and second growth populations at each location. Genetic...

  19. Physiology and growth of redwood and Douglas-fir planted after variable density retention outside redwood’s range

    Science.gov (United States)

    Lucy Kerhoulas; Nicholas Kerhoulas; Wade Polda; John-Pascal Berrill

    2017-01-01

    Reforestation following timber harvests is an important topic throughout the coast redwood (Sequoia sempervirens (D. Don) Endl.) range. Furthermore, as drought-induced mortality spreads across many of California’s forests, it is important to understand how physiology and stand structure influence reforestation success. Finally, as climate...

  20. Using wood quality measures to evaluate second-growth redwood

    Science.gov (United States)

    Stephen L. Quarles; Yana. Vlachovic

    2012-01-01

    Redwood (Sequoia sempervirens) a valued species for use in appearance grade applications, such as decking, exterior siding and interior paneling, because of its dimensional stability. It is also valued for certain exterior-use applications because of its natural decay resistance. Studies have found that young-growth redwood is less resistant to...

  1. Bat use of remnant old-growth redwood stands

    Science.gov (United States)

    William J. Zielinski; Steven T. Gellman

    1999-01-01

    Most of the old-growth redwood (Sequoia sempervirens) in Calfornia has been cut; regenerating forests will probably never resemble those that were harvested, and what old growth remains on private land occurs in small, isolated remnant patches. The landscapes in which these stands occur differ so markedly from their original condition that their...

  2. Cradle-to-gate life cycle impacts of redwood forest resource harvesting in northern California

    Science.gov (United States)

    Han-Sup Han; Elaine Oneil; Richard D. Bergman; Ivan L. Eastin; Leonard R. Johnson

    2015-01-01

    The first life cycle impact assessment for redwood (Sequoia sempervirens) forest management activities (i.e. a cradle-to-sawmill gate input) including the growing, harvesting, and hauling of redwood sawlogs to a sawmill was completed. In the stump-to-truck timber harvesting analysis, primary transport activities such as skidding and yarding consumed...

  3. Life-cycle assessment of redwood decking in the United States with a comparison to three other decking materials

    Science.gov (United States)

    R. Bergman; H. Sup-Han; E. Oneil; I. Eastin

    2013-01-01

    The goal of the study was to conduct a life-cycle inventory (LCI) of California redwood (Sequoia sempervirens) decking that would quantify the critical environmental impacts of decking from cradle to grave. Using that LCI data, a life-cycle assessment (LCA) was produced for redwood decking. The results were used to compare the environmental footprint...

  4. Natural seedlings and sprouts after regeneration cuttings in old-growth redwood

    Science.gov (United States)

    Kenneth N. Boe

    1975-01-01

    Natural regeneration of harvested old-growth stands of redwood (Sequoia sempervirens) is one way to start a new forest that is needed quickly for continuous timber production. Natural seedlings and sprouts developing after stands were cut were studied on the Redwood Experimental Forest, northern California. Three types of regeneration cuttings were...

  5. Predicting redwood productivity using biophysical data, spatial statistics and site quality indices

    Science.gov (United States)

    John-Pascal Berrill; Kevin L. O’Hara; Shawn Headley

    2017-01-01

    Coast redwood (Sequoia sempervirens (D. Don) Endl.) height growth and basal area growth are sensitive to variations in site quality. Site factors known to be correlated with redwood stand growth and yield include topographic variables such as position on slope, exposure, and the composite variable: topographic relative moisture index. Species...

  6. Visualization of Uncertain Contour Trees

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

  7. 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....

  8. ColorTree: a batch customization tool for phylogenic trees.

    Science.gov (United States)

    Chen, Wei-Hua; Lercher, Martin J

    2009-07-31

    Genome sequencing projects and comparative genomics studies typically aim to trace the evolutionary history of large gene sets, often requiring human inspection of hundreds of phylogenetic trees. If trees are checked for compatibility with an explicit null hypothesis (e.g., the monophyly of certain groups), this daunting task is greatly facilitated by an appropriate coloring scheme. In this note, we introduce ColorTree, a simple yet powerful batch customization tool for phylogenic trees. Based on pattern matching rules, ColorTree applies a set of customizations to an input tree file, e.g., coloring labels or branches. The customized trees are saved to an output file, which can then be viewed and further edited by Dendroscope (a freely available tree viewer). ColorTree runs on any Perl installation as a stand-alone command line tool, and its application can thus be easily automated. This way, hundreds of phylogenic trees can be customized for easy visual inspection in a matter of minutes. ColorTree allows efficient and flexible visual customization of large tree sets through the application of a user-supplied configuration file to multiple tree files.

  9. 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...... 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....

  10. Embedding complete ternary tree in hypercubes using AVL trees

    NARCIS (Netherlands)

    S.A. Choudum; I. Raman (Indhumathi)

    2008-01-01

    htmlabstractA complete ternary tree is a tree in which every non-leaf vertex has exactly three children. We prove that a complete ternary tree of height h, TTh, is embeddable in a hypercube of dimension . This result coincides with the result of [2]. However, in this paper, the embedding utilizes

  11. Portraits of Tree Families

    NARCIS (Netherlands)

    Balgooy, van M.M.J.

    1998-01-01

    With the publication of the second volume of the series ‘Malesian Seed Plants’, entitled ‘Portraits of Tree Families’, I would like to refer to the Introduction of the first volume, ‘Spot-characters’ for a historical background and an explanation of the aims of this series. The present book treats

  12. P{owering 'Trees

    Indian Academy of Sciences (India)

    Melia dubia Cav. of Meliaceae is a large deciduous tree. Leaves are compound with toothed leaflets. Flowers are small, greenish-yellow in much-branched inflorescences. Fruits are green, ellipsoidal with a single seed covered by hard portion ( as in a mango fruit) and surrounded by fleshy pulp outside. The bark is bitter ...

  13. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...

  14. Chapter 5 - Tree Mortality

    Science.gov (United States)

    Mark J. Ambrose

    2014-01-01

    Tree mortality is a natural process in all forest ecosystems. Extremely high mortality, however, can also be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

  15. 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)

  16. Base tree property

    Czech Academy of Sciences Publication Activity Database

    Balcar, B.; Doucha, Michal; Hrušák, M.

    2015-01-01

    Roč. 32, č. 1 (2015), s. 69-81 ISSN 0167-8094 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : forcing * Boolean algebras * base tree Subject RIV: BA - General Mathematics Impact factor: 0.614, year: 2015 http://link.springer.com/article/10.1007/s11083-013-9316-2

  17. Multiquarks and Steiner trees

    International Nuclear Information System (INIS)

    Richard, Jean-Marc

    2010-01-01

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

  18. 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.

  19. Selecting Landscape Plants: Shade Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012; Close, David

    2015-01-01

    Because of the permanency of trees and their importance in the landscape, care must be taken to select the best species for each situation. This publication goes over how to choose landscape trees that are shade tolerant.

  20. The ASC Sequoia Programming Model

    Energy Technology Data Exchange (ETDEWEB)

    Seager, M

    2008-08-06

    In the late 1980's and early 1990's, Lawrence Livermore National Laboratory was deeply engrossed in determining the next generation programming model for the Integrated Design Codes (IDC) beyond vectorization for the Cray 1s series of computers. The vector model, developed in mid 1970's first for the CDC 7600 and later extended from stack based vector operation to memory to memory operations for the Cray 1s, lasted approximately 20 years (See Slide 5). The Cray vector era was deemed an extremely long lived era as it allowed vector codes to be developed over time (the Cray 1s were faster in scalar mode than the CDC 7600) with vector unit utilization increasing incrementally over time. The other attributes of the Cray vector era at LLNL were that we developed, supported and maintained the Operating System (LTSS and later NLTSS), communications protocols (LINCS), Compilers (Civic Fortran77 and Model), operating system tools (e.g., batch system, job control scripting, loaders, debuggers, editors, graphics utilities, you name it) and math and highly machine optimized libraries (e.g., SLATEC, and STACKLIB). Although LTSS was adopted by Cray for early system generations, they later developed COS and UNICOS operating systems and environment on their own. In the late 1970s and early 1980s two trends appeared that made the Cray vector programming model (described above including both the hardware and system software aspects) seem potentially dated and slated for major revision. These trends were the appearance of low cost CMOS microprocessors and their attendant, departmental and mini-computers and later workstations and personal computers. With the wide spread adoption of Unix in the early 1980s, it appeared that LLNL (and the other DOE Labs) would be left out of the mainstream of computing without a rapid transition to these 'Killer Micros' and modern OS and tools environments. The other interesting advance in the period is that systems were being developed with multiple 'cores' in them and called Symmetric Multi-Processor or Shared Memory Processor (SMP) systems. The parallel revolution had begun. The Laboratory started a small 'parallel processing project' in 1983 to study the new technology and its application to scientific computing with four people: Tim Axelrod, Pete Eltgroth, Paul Dubois and Mark Seager. Two years later, Eugene Brooks joined the team. This team focused on Unix and 'killer micro' SMPs. Indeed, Eugene Brooks was credited with coming up with the 'Killer Micro' term. After several generations of SMP platforms (e.g., Sequent Balance 8000 with 8 33MHz MC32032s, Allian FX8 with 8 MC68020 and FPGA based Vector Units and finally the BB&N Butterfly with 128 cores), it became apparent to us that the killer micro revolution would indeed take over Crays and that we definitely needed a new programming and systems model. The model developed by Mark Seager and Dale Nielsen focused on both the system aspects (Slide 3) and the code development aspects (Slide 4). Although now succinctly captured in two attached slides, at the time there was tremendous ferment in the research community as to what parallel programming model would emerge, dominate and survive. In addition, we wanted a model that would provide portability between platforms of a single generation but also longevity over multiple--and hopefully--many generations. Only after we developed the 'Livermore Model' and worked it out in considerable detail did it become obvious that what we came up with was the right approach. In a nutshell, the applications programming model of the Livermore Model posited that SMP parallelism would ultimately not scale indefinitely and one would have to bite the bullet and implement MPI parallelism within the Integrated Design Code (IDC). We also had a major emphasis on doing everything in a completely standards based, portable methodology with POSIX/Unix as the target environment. We decided against specialized libraries like STACKLIB for performance, but kept as many general purpose, portable math libraries as were needed by the codes. Third, we assumed that the SMPs in clusters would evolve in time to become more powerful, feature rich and, in particular, offer more cores. Thus, we focused on OpenMP, and POSIX PThreads for programming SMP parallelism. These code porting efforts were lead by Dale Nielsen, A-Division code group leader, and Randy Christensen, B-Division code group leader. Most of the porting effort revolved removing 'Crayisms' in the codes: artifacts of LTSS/NLTSS, Civic compiler extensions beyond Fortran77, IO libraries and dealing with new code control languages (we switched to Perl and later to Python). Adding MPI to the codes was initially problematic and error prone because the programmers used MPI directly and sprinkled the calls throughout the code.

  1. 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....

  2. Introduction to fault tree analysis

    International Nuclear Information System (INIS)

    Barlow, R.E.; Lambert, H.E.

    1975-01-01

    An elementary, engineering oriented introduction to fault tree analysis is presented. The basic concepts, techniques and applications of fault tree analysis, FTA, are described. The two major steps of FTA are identified as (1) the construction of the fault tree and (2) its evaluation. The evaluation of the fault tree can be qualitative or quantitative depending upon the scope, extensiveness and use of the analysis. The advantages, limitations and usefulness of FTA are discussed

  3. The Re-Think Tree.

    Science.gov (United States)

    Gear, Jim

    1993-01-01

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

  4. 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…

  5. 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...

  6. Inferences from growing trees backwards

    Science.gov (United States)

    David W. Green; Kent A. McDonald

    1997-01-01

    The objective of this paper is to illustrate how longitudinal stress wave techniques can be useful in tracking the future quality of a growing tree. Monitoring the quality of selected trees in a plantation forest could provide early input to decisions on the effectiveness of management practices, or future utilization options, for trees in a plantation. There will...

  7. Genetic transformation of forest trees

    African Journals Online (AJOL)

    Admin

    In this review, the recent progress on genetic transformation of forest trees were discussed. Its described also, different applications of genetic engineering for improving forest trees or understanding the mechanisms governing genes expression in woody plants. Key words: Genetic transformation, transgenic forest trees, ...

  8. TREE SELECTING AND TREE RING MEASURING IN DENDROCHRONOLOGICAL INVESTIGATIONS

    Directory of Open Access Journals (Sweden)

    Sefa Akbulut

    2004-04-01

    Full Text Available Dendrochronology is a method of dating which makes use of the annual nature of tree growth. Dendrochronology may be divided into a number of subfields, each of which covers one or more aspects of the use of tree ring data: dendroclimatology, dendrogeomorphology, dendrohydrology, dendroecology, dendroarchaelogy, and dendrogylaciology. Basic of all form the analysis of the tree rings. The wood or tree rings can aid to dating past events about climatology, ecology, geology, hydrology. Dendrochronological studies are conducted either on increment cores or on discs. It may be seen abnormalities on tree rings during the measurement like that false rings, missing rings, reaction wood. Like that situation, increment cores must be extracted from four different sides of each tree and be studied as more as on tree.

  9. Tree Colors: Color Schemes for Tree-Structured Data.

    Science.gov (United States)

    Tennekes, Martijn; de Jonge, Edwin

    2014-12-01

    We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

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

    2014-03-06

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

  11. Fault tree analysis

    International Nuclear Information System (INIS)

    1981-09-01

    Suggestion are made concerning the method of the fault tree analysis, the use of certain symbols in the examination of system failures. This purpose of the fault free analysis is to find logical connections of component or subsystem failures leading to undesirable occurrances. The results of these examinations are part of the system assessment concerning operation and safety. The objectives of the analysis are: systematical identification of all possible failure combinations (causes) leading to a specific undesirable occurrance, finding of reliability parameters such as frequency of failure combinations, frequency of the undesirable occurrance or non-availability of the system when required. The fault tree analysis provides a near and reconstructable documentation of the examination. (orig./HP) [de

  12. Tree-level formalism

    International Nuclear Information System (INIS)

    Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele

    2011-01-01

    We review two novel techniques used to calculate tree-level scattering amplitudes efficiently: MHV diagrams, and on-shell recursion relations. For the MHV diagrams, we consider applications to tree-level amplitudes and focus in particular on the N=4 supersymmetric formulation. We also briefly describe the derivation of loop amplitudes using MHV diagrams. For the recursion relations, after presenting their general proof, we discuss several applications to massless theories with and without supersymmetry, to theories with massive particles, and to graviton amplitudes in general relativity. This article is an invited review for a special issue of Journal of Physics A: Mathematical and Theoretical devoted to 'Scattering amplitudes in gauge theories'. (review)

  13. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

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

  14. 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.

  15. Recursive Trees for Practical ORAM

    Directory of Open Access Journals (Sweden)

    Moataz Tarik

    2015-06-01

    Full Text Available We present a new, general data structure that reduces the communication cost of recent tree-based ORAMs. Contrary to ORAM trees with constant height and path lengths, our new construction r-ORAM allows for trees with varying shorter path length. Accessing an element in the ORAM tree results in different communication costs depending on the location of the element. The main idea behind r-ORAM is a recursive ORAM tree structure, where nodes in the tree are roots of other trees. While this approach results in a worst-case access cost (tree height at most as any recent tree-based ORAM, we show that the average cost saving is around 35% for recent binary tree ORAMs. Besides reducing communication cost, r-ORAM also reduces storage overhead on the server by 4% to 20% depending on the ORAM’s client memory type. To prove r-ORAM’s soundness, we conduct a detailed overflow analysis. r-ORAM’s recursive approach is general in that it can be applied to all recent tree ORAMs, both constant and poly-log client memory ORAMs. Finally, we implement and benchmark r-ORAM in a practical setting to back up our theoretical claims.

  16. Mathematical foundations of event trees

    International Nuclear Information System (INIS)

    Papazoglou, Ioannis A.

    1998-01-01

    A mathematical foundation from first principles of event trees is presented. The main objective of this formulation is to offer a formal basis for developing automated computer assisted construction techniques for event trees. The mathematical theory of event trees is based on the correspondence between the paths of the tree and the elements of the outcome space of a joint event. The concept of a basic cylinder set is introduced to describe joint event outcomes conditional on specific outcomes of basic events or unconditional on the outcome of basic events. The concept of outcome space partition is used to describe the minimum amount of information intended to be preserved by the event tree representation. These concepts form the basis for an algorithm for systematic search for and generation of the most compact (reduced) form of an event tree consistent with the minimum amount of information the tree should preserve. This mathematical foundation allows for the development of techniques for automated generation of event trees corresponding to joint events which are formally described through other types of graphical models. Such a technique has been developed for complex systems described by functional blocks and it is reported elsewhere. On the quantification issue of event trees, a formal definition of a probability space corresponding to the event tree outcomes is provided. Finally, a short discussion is offered on the relationship of the presented mathematical theory with the more general use of event trees in reliability analysis of dynamic systems

  17. Making CSB + -Trees Processor Conscious

    DEFF Research Database (Denmark)

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

    2005-01-01

    of the CSB+-tree. We argue that it is necessary to consider a larger group of parameters in order to adapt CSB+-tree to processor architectures as different as Pentium and Itanium. We identify this group of parameters and study how it impacts the performance of CSB+-tree on Itanium 2. Finally, we propose......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 performance...... 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....

  18. Submodular unsplittable flow on trees

    DEFF Research Database (Denmark)

    Adamaszek, Anna Maria; Chalermsook, Parinya; Ene, Alina

    2016-01-01

    We study the Unsplittable Flow problem (UFP) on trees with a submodular objective function. The input to this problem is a tree with edge capacities and a collection of tasks, each characterized by a source node, a sink node, and a demand. A subset of the tasks is feasible if the tasks can...... simultaneously send their demands from the source to the sink without violating the edge capacities. The goal is to select a feasible subset of the tasks that maximizes a submodular objective function. Our main result is an O(k log n)-approximation algorithm for Submodular UFP on trees where k denotes...... the pathwidth of the given tree. Since every tree has pathwidth O(log n), we obtain an O(log2 n) approximation for arbitrary trees. This is the first non-trivial approximation guarantee for the problem and it matches the best approximation known for UFP on trees with a linear objective function. Our main...

  19. (Almost) practical tree codes

    KAUST Repository

    Khina, Anatoly

    2016-08-15

    We consider the problem of stabilizing an unstable plant driven by bounded noise over a digital noisy communication link, a scenario at the heart of networked control. To stabilize such a plant, one needs real-time encoding and decoding with an error probability profile that decays exponentially with the decoding delay. The works of Schulman and Sahai over the past two decades have developed the notions of tree codes and anytime capacity, and provided the theoretical framework for studying such problems. Nonetheless, there has been little practical progress in this area due to the absence of explicit constructions of tree codes with efficient encoding and decoding algorithms. Recently, linear time-invariant tree codes were proposed to achieve the desired result under maximum-likelihood decoding. In this work, we take one more step towards practicality, by showing that these codes can be efficiently decoded using sequential decoding algorithms, up to some loss in performance (and with some practical complexity caveats). We supplement our theoretical results with numerical simulations that demonstrate the effectiveness of the decoder in a control system setting.

  20. 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.

  1. On Determining if Tree-based Networks Contain Fixed Trees.

    Science.gov (United States)

    Anaya, Maria; Anipchenko-Ulaj, Olga; Ashfaq, Aisha; Chiu, Joyce; Kaiser, Mahedi; Ohsawa, Max Shoji; Owen, Megan; Pavlechko, Ella; St John, Katherine; Suleria, Shivam; Thompson, Keith; Yap, Corrine

    2016-05-01

    We address an open question of Francis and Steel about phylogenetic networks and trees. They give a polynomial time algorithm to decide if a phylogenetic network, N, is tree-based and pose the problem: given a fixed tree T and network N, is N based on T? We show that it is [Formula: see text]-hard to decide, by reduction from 3-Dimensional Matching (3DM) and further that the problem is fixed-parameter tractable.

  2. Trees in the city: valuing street trees in Portland, Oregon

    Science.gov (United States)

    G.H. Donovan; D.T. Butry

    2010-01-01

    We use a hedonic price model to simultaneously estimate the effects of street trees on the sales price and the time-on-market (TOM) of houses in Portland. Oregon. On average, street trees add $8,870 to sales price and reduce TOM by 1.7 days. In addition, we found that the benefits of street trees spill over to neighboring houses. Because the provision and maintenance...

  3. Systolic trees and systolic language recognition by tree automata

    Energy Technology Data Exchange (ETDEWEB)

    Steinby, M

    1983-01-01

    K. Culik II, J. Gruska, A. Salomaa and D. Wood have studied the language recognition capabilities of certain types of systolically operating networks of processors (see research reports Cs-81-32, Cs-81-36 and Cs-82-01, Univ. of Waterloo, Ontario, Canada). In this paper, their model for systolic VLSI trees is formalised in terms of standard tree automaton theory, and the way in which some known facts about recognisable forests and tree transductions can be applied in VLSI tree theory is demonstrated. 13 references.

  4. 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...

  5. Human decision error (HUMDEE) trees

    International Nuclear Information System (INIS)

    Ostrom, L.T.

    1993-01-01

    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

  6. Phylogenetic trees and Euclidean embeddings.

    Science.gov (United States)

    Layer, Mark; Rhodes, John A

    2017-01-01

    It was recently observed by de Vienne et al. (Syst Biol 60(6):826-832, 2011) that a simple square root transformation of distances between taxa on a phylogenetic tree allowed for an embedding of the taxa into Euclidean space. While the justification for this was based on a diffusion model of continuous character evolution along the tree, here we give a direct and elementary explanation for it that provides substantial additional insight. We use this embedding to reinterpret the differences between the NJ and BIONJ tree building algorithms, providing one illustration of how this embedding reflects tree structures in data.

  7. Occurrence of leguminous trees

    Energy Technology Data Exchange (ETDEWEB)

    Kirkbride, J.H.; Arkcoll, D.B.A.; Turnbull, J.W.; Magalhaes, L.M.S.; Fernandes, N.P.

    1984-01-01

    Five papers from the symposium are presented. Kirkbride, J.H. Jr.; Legumes of the cerrado. pp 23-46 (Refs. 55) A review is given. Some 548 legume species in 59 genera are listed that have been reported from cerrado vegetation. Felker, P.; Legume trees in semi-arid and arid areas. pp 47-59 (Refs. 41) A review is given of worldwide research activities. Arkcoll, D.B.; A comparison of some fast growing species suitable for woodlots in the wet tropics. pp 61-68 (Refs. 9) Studies are described near Manaus on intensive silviculture (for fuelwood production) of Eucalyptus deglupta, Cedrelinga catanaeformis (catenaeformis), Jacaranda copaia, and Inga edulis. Turnbull, J.W.; Six phyllodinous Acacia species for planting in the humid tropical lowlands. pp 69-73 (Refs. 14) Distribution, ecology, growth, and utilization are described for A. auriculiformis, A. mangium, A. aulacocarpa, A. crassicarpa, A. cincinnata, and A. polystachya. Magalhaes, L.M.S., Fernandes, N.P.; Experimental stands of leguminous trees in the Manaus region. pp 75-79 (Refs. 8) Performance up to age 20 yr of Cedrelinga catenaeformis, Dalbergia nigra, Dinizia excelsa, Dipteryx odorata, Dipteryx sp., Diplotropis sp., Eperua bijuga, Pithecellobium racemosum, Vouacapoua pallidior, and Hymenaea sp. is described.

  8. 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...

  9. Genealogy and gene trees.

    Science.gov (United States)

    Rasmuson, Marianne

    2008-02-01

    Heredity can be followed in persons or in genes. Persons can be identified only a few generations back, but simplified models indicate that universal ancestors to all now living persons have occurred in the past. Genetic variability can be characterized as variants of DNA sequences. Data are available only from living persons, but from the pattern of variation gene trees can be inferred by means of coalescence models. The merging of lines backwards in time leads to a MRCA (most recent common ancestor). The time and place of living for this inferred person can give insights in human evolutionary history. Demographic processes are incorporated in the model, but since culture and customs are known to influence demography the models used ought to be tested against available genealogy. The Icelandic data base offers a possibility to do so and points to some discrepancies. Mitochondrial DNA and Y chromosome patterns give a rather consistent view of human evolutionary history during the latest 100 000 years but the earlier epochs of human evolution demand gene trees with longer branches. The results of such studies reveal as yet unsolved problems about the sources of our genome.

  10. 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.

  11. Visualizing Individual Tree Differences in Tree-Ring Studies

    Directory of Open Access Journals (Sweden)

    Mario Trouillier

    2018-04-01

    Full Text Available Averaging tree-ring measurements from multiple individuals is one of the most common procedures in dendrochronology. It serves to filter out noise from individual differences between trees, such as competition, height, and micro-site effects, which ideally results in a site chronology sensitive to regional scale factors such as climate. However, the climate sensitivity of individual trees can be modulated by factors like competition, height, and nitrogen deposition, calling attention to whether average chronologies adequately assess climatic growth-control. In this study, we demonstrate four simple but effective methods to visually assess differences between individual trees. Using individual tree climate-correlations we: (1 employed jitter plots with superimposed metadata to assess potential causes for these differences; (2 plotted the frequency distributions of climate correlations over time as heat maps; (3 mapped the spatial distribution of climate sensitivity over time to assess spatio-temporal dynamics; and (4 used t-distributed Stochastic Neighborhood Embedding (t-SNE to assess which trees were generally more similar in terms of their tree-ring pattern and their correlation with climate variables. This suite of exploratory methods can indicate if individuals in tree-ring datasets respond differently to climate variability, and therefore, should not solely be explored with climate correlations of the mean population chronology.

  12. Tree Size Comparison of Some Important Street Trees Growing at ...

    African Journals Online (AJOL)

    PROF HORSFALL

    More research is needed on these trees for healthy environment of city. The present ..... use and CO2 emissions from power plants. Environ. Poll. .... Anna. Bot., 65:567-574. Kozlowski, T.T., 1971. Growth and Development of. Trees. Vol. 1.

  13. Relating phylogenetic trees to transmission trees of infectious disease outbreaks.

    Science.gov (United States)

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

    2013-11-01

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

  14. 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…

  15. Picking a tree: habitat use by the tree agama, Acanthocercus ...

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

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

    2004-01-01

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

  17. Better trees through systematic breeding

    Science.gov (United States)

    Robert Z. Callaham

    1957-01-01

    Today I would like to tell you briefly about the efforts of forest geneticists to improve the quality of forest trees. What do we mean by quality? Here, the consumer has the first word. The trees we produce are primarily for timber production, and the timber growing and wood-using industries give us our guidelines. Nevertheless, many of the characteristics sought by...

  18. Tree physiology and bark beetles

    Science.gov (United States)

    Michael G. Ryan; Gerard Sapes; Anna Sala; Sharon Hood

    2015-01-01

    Irruptive bark beetles usually co-occur with their co-evolved tree hosts at very low (endemic) population densities. However, recent droughts and higher temperatures have promoted widespread tree mortality with consequences for forest carbon, fire and ecosystem services (Kurz et al., 2008; Raffa et al., 2008; Jenkins et al., 2012). In this issue of New Phytologist,...

  19. 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…

  20. Boosted decision trees and applications

    International Nuclear Information System (INIS)

    Coadou, Y.

    2013-01-01

    Decision trees are a machine learning technique more and more commonly used in high energy physics, while it has been widely used in the social sciences. After introducing the concepts of decision trees, this article focuses on its application in particle physics. (authors)

  1. Who pays for tree improvement?

    Science.gov (United States)

    Tom D. Byram; E. M. Raley

    2011-01-01

    Tree improvement has been one of the most successful collaborative research efforts in history, eliciting participation from a wide variety of players. This effort has included state forestry agencies, research universities, integrated forest industries, and the USDA Forest Service. Tree improvement was organized through cooperatives whose objectives were to distribute...

  2. Mean-field lattice trees

    NARCIS (Netherlands)

    Borgs, C.; Chayes, J.T.; Hofstad, van der R.W.; Slade, G.

    1999-01-01

    We introduce a mean-field model of lattice trees based on embeddings into d of abstract trees having a critical Poisson offspring distribution. This model provides a combinatorial interpretation for the self-consistent mean-field model introduced previously by Derbez and Slade [9], and provides an

  3. 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

  4. Decision trees in epidemiological research

    Directory of Open Access Journals (Sweden)

    Ashwini Venkatasubramaniam

    2017-09-01

    Full Text Available Abstract Background In many studies, it is of interest to identify population subgroups that are relatively homogeneous with respect to an outcome. The nature of these subgroups can provide insight into effect mechanisms and suggest targets for tailored interventions. However, identifying relevant subgroups can be challenging with standard statistical methods. Main text We review the literature on decision trees, a family of techniques for partitioning the population, on the basis of covariates, into distinct subgroups who share similar values of an outcome variable. We compare two decision tree methods, the popular Classification and Regression tree (CART technique and the newer Conditional Inference tree (CTree technique, assessing their performance in a simulation study and using data from the Box Lunch Study, a randomized controlled trial of a portion size intervention. Both CART and CTree identify homogeneous population subgroups and offer improved prediction accuracy relative to regression-based approaches when subgroups are truly present in the data. An important distinction between CART and CTree is that the latter uses a formal statistical hypothesis testing framework in building decision trees, which simplifies the process of identifying and interpreting the final tree model. We also introduce a novel way to visualize the subgroups defined by decision trees. Our novel graphical visualization provides a more scientifically meaningful characterization of the subgroups identified by decision trees. Conclusions Decision trees are a useful tool for identifying homogeneous subgroups defined by combinations of individual characteristics. While all decision tree techniques generate subgroups, we advocate the use of the newer CTree technique due to its simplicity and ease of interpretation.

  5. Decision trees in epidemiological research.

    Science.gov (United States)

    Venkatasubramaniam, Ashwini; Wolfson, Julian; Mitchell, Nathan; Barnes, Timothy; JaKa, Meghan; French, Simone

    2017-01-01

    In many studies, it is of interest to identify population subgroups that are relatively homogeneous with respect to an outcome. The nature of these subgroups can provide insight into effect mechanisms and suggest targets for tailored interventions. However, identifying relevant subgroups can be challenging with standard statistical methods. We review the literature on decision trees, a family of techniques for partitioning the population, on the basis of covariates, into distinct subgroups who share similar values of an outcome variable. We compare two decision tree methods, the popular Classification and Regression tree (CART) technique and the newer Conditional Inference tree (CTree) technique, assessing their performance in a simulation study and using data from the Box Lunch Study, a randomized controlled trial of a portion size intervention. Both CART and CTree identify homogeneous population subgroups and offer improved prediction accuracy relative to regression-based approaches when subgroups are truly present in the data. An important distinction between CART and CTree is that the latter uses a formal statistical hypothesis testing framework in building decision trees, which simplifies the process of identifying and interpreting the final tree model. We also introduce a novel way to visualize the subgroups defined by decision trees. Our novel graphical visualization provides a more scientifically meaningful characterization of the subgroups identified by decision trees. Decision trees are a useful tool for identifying homogeneous subgroups defined by combinations of individual characteristics. While all decision tree techniques generate subgroups, we advocate the use of the newer CTree technique due to its simplicity and ease of interpretation.

  6. Totally optimal decision trees for Boolean functions

    KAUST Repository

    Chikalov, Igor; Hussain, Shahid; Moshkov, Mikhail

    2016-01-01

    We study decision trees which are totally optimal relative to different sets of complexity parameters for Boolean functions. A totally optimal tree is an optimal tree relative to each parameter from the set simultaneously. We consider the parameters

  7. Regeneration Dynamics of Coast Redwood, a Sprouting Conifer Species: A Review with Implications for Management and Restoration

    Directory of Open Access Journals (Sweden)

    Kevin L. O’Hara

    2017-04-01

    Full Text Available Coast redwood (Sequoia sempervirens (Lamb. ex. D. Don Endl. is unique among conifer species because of its longevity, the great sizes of individual trees, and its propensity to reproduce through sprouts. Timber harvesting in the native redwood range along the coast of the western United States has necessitated restoration aimed to promote old forest structures to increase the total amount of old forest, the connectivity between old forests, and to enhance the resiliency of these ecosystems. After disturbance or harvest, healthy redwood stumps sprout vigorously, often producing dozens of sprouts within two years of disturbance. These sprouts form highly aggregated spatial patterns because they are clustered around stumps that may number less than 50 ha−1. Thinning of sprouts can accelerate individual tree growth, providing an effective restoration strategy to accelerate formation of large trees and old forest structures or increase stand growth for timber production. However, management, including restoration activities, is a contentious issue throughout the native range of redwood because of the history of overexploitation of this resource and perceptions that overexploitation is continuing. This paper reviews the science of early stand dynamics in coast redwood and their implications for restoration and other silvicultural strategies.

  8. 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.

  9. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  10. Linking and Cutting Spanning Trees

    Directory of Open Access Journals (Sweden)

    Luís M. S. Russo

    2018-04-01

    Full Text Available We consider the problem of uniformly generating a spanning tree for an undirected connected graph. This process is useful for computing statistics, namely for phylogenetic trees. We describe a Markov chain for producing these trees. For cycle graphs, we prove that this approach significantly outperforms existing algorithms. For general graphs, experimental results show that the chain converges quickly. This yields an efficient algorithm due to the use of proper fast data structures. To obtain the mixing time of the chain we describe a coupling, which we analyze for cycle graphs and simulate for other graphs.

  11. Tree Ordination as Invented Tradition

    Directory of Open Access Journals (Sweden)

    Avery Morrow

    2012-01-01

    Full Text Available The symbolic ordination of trees as monks in Thailand is widely perceived in Western scholarship to be proof of the power of Buddhism to spur ecological thought. However, a closer analysis of tree ordination demonstrates that it is not primarily about Buddhist teaching, but rather is an invented tradition based on the sanctity of Thai Buddhist symbols as well as those of spirit worship and the monarchy. Tree ordinations performed by non-Buddhist minorities in Thailand do not demonstrate a religious commitment but rather a political one.

  12. Tree Coding of Bilevel Images

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1998-01-01

    Presently, sequential tree coders are the best general purpose bilevel image coders and the best coders of halftoned images. The current ISO standard, Joint Bilevel Image Experts Group (JBIG), is a good example. A sequential tree coder encodes the data by feeding estimates of conditional...... 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...... images such as halftones. By utilizing randomized subsampling in the template selection, the speed becomes acceptable for practical image coding...

  13. Multiple-purpose trees for pastoral farming in New Zealand: with emphasis on tree legumes. [Lucerne Tree: Medick Tree

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D J.G.; Macfarlane, R P

    1979-01-01

    The potential for soil conservation and agroforestry of several native and exotic legumes is discussed. Flowering period, chemical composition of leaves/pods, hardiness to frost and drought, timber value, forage potential for livestock and bees, ornamental value and other products are tabulated with information on up to 38 species. Two low-growing species that have proved useful for slope stabilization as well as forage are tree lucerne (Cytisus palmensis) and tree medick (Medicago arborea), the latter being shrubby and more suitable for cold districts. Gleditsia triacanthos is recommended as a shade and fodder tree for farm pasture.

  14. Generalising tree traversals to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2015-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal and then apply it to compact graph representations of trees instead. The resulting graph traversals avoid...... is not sound. Therefore, we complement our implementation of the recursion scheme with a number of correspondence theorems that ensure soundness for various classes of traversals. We illustrate the practical applicability of the implementation as well as the complementing theory with a number of examples....

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

    Science.gov (United States)

    Eilmann, Britta; Rigling, Andreas

    2012-02-01

    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 species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

  16. TreeCluster: Massively scalable transmission clustering using phylogenetic trees

    OpenAIRE

    Moshiri, Alexander

    2018-01-01

    Background: The ability to infer transmission clusters from molecular data is critical to designing and evaluating viral control strategies. Viral sequencing datasets are growing rapidly, but standard methods of transmission cluster inference do not scale well beyond thousands of sequences. Results: I present TreeCluster, a cross-platform tool that performs transmission cluster inference on a given phylogenetic tree orders of magnitude faster than existing inference methods and supports multi...

  17. Moose?tree interactions: rebrowsing is common across tree species

    OpenAIRE

    Mathisen, Karen Marie; Milner, Jos M.; Skarpe, Christina

    2017-01-01

    Background Plant strategies to resist herbivory include tolerance and avoidance. Tolerance strategies, such as rapid regrowth which increases the palatability of new shoots, can lead to positive feedback loops between plants and herbivores. An example of such a positive feedback occurs when moose (Alces alces) browse trees in boreal forests. We described the degree of change in tree morphology that accumulated over time in response to repeated browsing by moose, using an index of accumulated ...

  18. Resummed tree heptagon

    Science.gov (United States)

    Belitsky, A. V.

    2018-04-01

    The form factor program for the regularized space-time S-matrix in planar maximally supersymmetric gauge theory, known as the pentagon operator product expansion, is formulated in terms of flux-tube excitations propagating on a dual two-dimensional world-sheet, whose dynamics is known exactly as a function of 't Hooft coupling. Both MHV and non-MHV amplitudes are described in a uniform, systematic fashion within this framework, with the difference between the two encoded in coupling-dependent helicity form factors expressed via Zhukowski variables. The nontrivial SU(4) tensor structure of flux-tube transitions is coupling independent and is known for any number of charged excitations from solutions of a system of Watson and Mirror equations. This description allows one to resum the infinite series of form factors and recover the space-time S-matrix exactly in kinematical variables at a given order of perturbation series. Recently, this was done for the hexagon. Presently, we successfully perform resummation for the seven-leg tree NMHV amplitude. To this end, we construct the flux-tube integrands of the fifteen independent Grassmann component of the heptagon with an infinite number of small fermion-antifermion pairs accounted for in NMHV two-channel conformal blocks.

  19. Random ancestor trees

    International Nuclear Information System (INIS)

    Ben-Naim, E; Krapivsky, P L

    2010-01-01

    We investigate a network growth model in which the genealogy controls the evolution. In this model, a new node selects a random target node and links either to this target node, or to its parent, or to its grandparent, etc; all nodes from the target node to its most ancient ancestor are equiprobable destinations. The emerging random ancestor tree is very shallow: the fraction g n of nodes at distance n from the root decreases super-exponentially with n, g n = e −1 /(n − 1)!. We find that a macroscopic hub at the root coexists with highly connected nodes at higher generations. The maximal degree of a node at the nth generation grows algebraically as N 1/β n , where N is the system size. We obtain the series of nontrivial exponents which are roots of transcendental equations: β 1 ≅1.351 746, β 2 ≅1.682 201, etc. As a consequence, the fraction p k of nodes with degree k has an algebraic tail, p k ∼ k −γ , with γ = β 1 + 1 = 2.351 746

  20. Trees as metal scavengers

    International Nuclear Information System (INIS)

    Hallman, N.

    2000-01-01

    Full text: Tree roots extract metal ions form wet soils in two different ways. At the soil/root hair interface soluble ions in contact with the cellulose wall move through it and enter the cell through the plasmalemma; the semi permeable membrane that encloses every living cell. Some ions, especially those that are part of cellular metabolic processes eg. Na, K, Fe, Mg, S move into the cytoplasm, are bound into organic complexes and travel from cell to cell within the cytoplasm. This requires energy, and the amount of any of these metabolically active ions taken in tends to be regulated by the plant. The movement of the ions from cell to cell is slow, selective, and regulated by requirements of synthesis of for example Mg in the chlorophyll molecule. This means that more Mg is transported to cells of leaves than of cells of roots. This movement of ions is simplistic, or within the cytoplasm. Other ions are swept along in the transpiration stream and enter the complex plumbing system that brings water to the leaves for metabolism and cooling. Water in this apoplastic pathway travels within the pipes (xylem) of the wood and in the cellulose of the walls. It travels along essentially non-living parts of the plant. Ions such as As, Pb, Ni, Cr accumulate in sites such as leaves and bark. Analysis of plant parts can indicate the presence of heavy metals and can give an indication of ore bodies within the root zone

  1. The Tree of Industrial Life

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2002-01-01

    The purpose of this paper is to bring forth an interaction between evolutionary economics and industrial systematics. The suggested solution is to reconstruct the "family tree" of the industries. Such a tree is based on similarities, but it may also reflect the evolutionary history in industries....... For this purpose the paper shows how matrices of input-output coefficients can be transformed into binary characteristics matrices and to distance matrices, and it also discusses the possible evolutionary meaning of this translation. Then these derived matrices are used as inputs to algorithms for the heuristic...... finding of optimal industrial trees. The results are presented as taxonomic trees that can easily be compared with the hierarchical structure of existing systems of industrial classification....

  2. Fremont Tree-Well Filter

    Science.gov (United States)

    Information about the SFBWQP Fremont Tree-Well Filter Spine project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  3. 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.

  4. Decision tree modeling using R.

    Science.gov (United States)

    Zhang, Zhongheng

    2016-08-01

    In machine learning field, decision tree learner is powerful and easy to interpret. It employs recursive binary partitioning algorithm that splits the sample in partitioning variable with the strongest association with the response variable. The process continues until some stopping criteria are met. In the example I focus on conditional inference tree, which incorporates tree-structured regression models into conditional inference procedures. While growing a single tree is subject to small changes in the training data, random forests procedure is introduced to address this problem. The sources of diversity for random forests come from the random sampling and restricted set of input variables to be selected. Finally, I introduce R functions to perform model based recursive partitioning. This method incorporates recursive partitioning into conventional parametric model building.

  5. 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....

  6. Distance labeling schemes for trees

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben

    2016-01-01

    We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoille...... variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta...

  7. Generic physical protection logic trees

    International Nuclear Information System (INIS)

    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

  8. Border trees of complex networks

    International Nuclear Information System (INIS)

    Villas Boas, Paulino R; Rodrigues, Francisco A; Travieso, Gonzalo; Fontoura Costa, Luciano da

    2008-01-01

    The comprehensive characterization of the structure of complex networks is essential to understand the dynamical processes which guide their evolution. The discovery of the scale-free distribution and the small-world properties of real networks were fundamental to stimulate more realistic models and to understand important dynamical processes related to network growth. However, the properties of the network borders (nodes with degree equal to 1), one of its most fragile parts, remained little investigated and understood. The border nodes may be involved in the evolution of structures such as geographical networks. Here we analyze the border trees of complex networks, which are defined as the subgraphs without cycles connected to the remainder of the network (containing cycles) and terminating into border nodes. In addition to describing an algorithm for identification of such tree subgraphs, we also consider how their topological properties can be quantified in terms of their depth and number of leaves. We investigate the properties of border trees for several theoretical models as well as real-world networks. Among the obtained results, we found that more than half of the nodes of some real-world networks belong to the border trees. A power-law with cut-off was observed for the distribution of the depth and number of leaves of the border trees. An analysis of the local role of the nodes in the border trees was also performed

  9. 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.

  10. Objective consensus from decision trees

    International Nuclear Information System (INIS)

    Putora, Paul Martin; Panje, Cedric M; Papachristofilou, Alexandros; Pra, Alan Dal; Hundsberger, Thomas; Plasswilm, Ludwig

    2014-01-01

    Consensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources. Based on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus. Based on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters. Recommendations represented as decision trees can serve as a basis for objective consensus among multiple parties

  11. Objective consensus from decision trees.

    Science.gov (United States)

    Putora, Paul Martin; Panje, Cedric M; Papachristofilou, Alexandros; Dal Pra, Alan; Hundsberger, Thomas; Plasswilm, Ludwig

    2014-12-05

    Consensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources. Based on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus. Based on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters. Recommendations represented as decision trees can serve as a basis for objective consensus among multiple parties.

  12. Longest common extensions in trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gawrychowski, Pawel; Gørtz, Inge Li

    2016-01-01

    to trees and suggest a few applications of LCE in trees to tries and XML databases. Given a labeled and rooted tree T of size n, the goal is to preprocess T into a compact data structure that support the following LCE queries between subpaths and subtrees in T. Let v1, v2, w1, and w2 be nodes of T...... such that w1 and w2 are descendants of v1 and v2 respectively. - LCEPP(v1, w1, v2, w2): (path-path LCE) return the longest common prefix of the paths v1 ~→ w1 and v2 ~→ w2. - LCEPT(v1, w1, v2): (path-tree LCE) return maximal path-path LCE of the path v1 ~→ w1 and any path from v2 to a descendant leaf. - LCETT......(v1, v2): (tree-tree LCE) return a maximal path-path LCE of any pair of paths from v1 and v2 to descendant leaves. We present the first non-trivial bounds for supporting these queries. For LCEPP queries, we present a linear-space solution with O(log* n) query time. For LCEPT queries, we present...

  13. Longest Common Extensions in Trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gawrychowski, Pawel; Gørtz, Inge Li

    2015-01-01

    to trees and suggest a few applications of LCE in trees to tries and XML databases. Given a labeled and rooted tree T of size n, the goal is to preprocess T into a compact data structure that support the following LCE queries between subpaths and subtrees in T. Let v1, v2, w1, and w2 be nodes of T...... such that w1 and w2 are descendants of v1 and v2 respectively. - LCEPP(v1, w1, v2, w2): (path-path LCE) return the longest common prefix of the paths v1 ~→ w1 and v2 ~→ w2. - LCEPT(v1, w1, v2): (path-tree LCE) return maximal path-path LCE of the path v1 ~→ w1 and any path from v2 to a descendant leaf. - LCETT......(v1, v2): (tree-tree LCE) return a maximal path-path LCE of any pair of paths from v1 and v2 to descendant leaves. We present the first non-trivial bounds for supporting these queries. For LCEPP queries, we present a linear-space solution with O(log* n) query time. For LCEPT queries, we present...

  14. Factors that influence Christmas tree sales

    Science.gov (United States)

    Thomas H. Pendleton; Lawrence D. Garrett

    1970-01-01

    An analysis of the metropolitan Christmas tree market in Winston-Salem, N. C., shows that to sell more trees, Christmas tree retailers should locate their lots on heavily traveled streets in business areas, have adequate parking facilities, advertise, and have attractive displays of trees. Retailers who follow these practices can expect to receive higher prices for...

  15. Critical wind speed at which trees break

    Science.gov (United States)

    Virot, E.; Ponomarenko, A.; Dehandschoewercker, É.; Quéré, D.; Clanet, C.

    2016-02-01

    Data from storms suggest that the critical wind speed at which trees break is constant (≃42 m /s ), regardless of tree characteristics. We question the physical origin of this observation both experimentally and theoretically. By combining Hooke's law, Griffith's criterion, and tree allometry, we show that the critical wind speed indeed hardly depends on the height, diameter, and elastic properties of trees.

  16. Field guide to red tree vole nests

    Science.gov (United States)

    Damon B. Lesmeister; James K. Swingle

    2017-01-01

    Surveys for red tree vole (Arborimus longicaudus) nests require tree climbing because the species is a highly specialized arboreal rodent that live in the tree canopy of coniferous forests in western Oregon and northwestern California. Tree voles are associated with old coniferous forest (≥80 years old) that are structurally complex, but are often...

  17. Mitered fractal trees: constructions and properties

    NARCIS (Netherlands)

    Verhoeff, T.; Verhoeff, K.; Bosch, R.; McKenna, D.; Sarhangi, R.

    2012-01-01

    Tree-like structures, that is, branching structures without cycles, are attractive for artful expression. Especially interesting are fractal trees, where each subtree is a scaled and possibly otherwise transformed version of the entire tree. Such trees can be rendered in 3D by using beams with a

  18. Critical wind speed at which trees break.

    Science.gov (United States)

    Virot, E; Ponomarenko, A; Dehandschoewercker, É; Quéré, D; Clanet, C

    2016-02-01

    Data from storms suggest that the critical wind speed at which trees break is constant (≃42m/s), regardless of tree characteristics. We question the physical origin of this observation both experimentally and theoretically. By combining Hooke's law, Griffith's criterion, and tree allometry, we show that the critical wind speed indeed hardly depends on the height, diameter, and elastic properties of trees.

  19. 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

  20. Colourings of (k-r,k-trees

    Directory of Open Access Journals (Sweden)

    M. Borowiecki

    2017-01-01

    Full Text Available Trees are generalized to a special kind of higher dimensional complexes known as \\((j,k\\-trees ([L. W. Beineke, R. E. Pippert, On the structure of \\((m,n\\-trees, Proc. 8th S-E Conf. Combinatorics, Graph Theory and Computing, 1977, 75-80], and which are a natural extension of \\(k\\-trees for \\(j=k-1\\. The aim of this paper is to study\\((k-r,k\\-trees ([H. P. Patil, Studies on \\(k\\-trees and some related topics, PhD Thesis, University of Warsaw, Poland, 1984], which are a generalization of \\(k\\-trees (or usual trees when \\(k=1\\. We obtain the chromatic polynomial of \\((k-r,k\\-trees and show that any two \\((k-r,k\\-trees of the same order are chromatically equivalent. However, if \\(r\

  1. 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.

  2. Tree Notation: an antifragile program notation

    OpenAIRE

    Yunits, Breck

    2017-01-01

    This paper presents Tree Notation, a new simple, universal syntax. Language designers can invent new programming languages, called Tree Languages, on top of Tree Notation. Tree Languages have a number of advantages over traditional programming languages. We include a Visual Abstract to succinctly display the problem and discovery. Then we describe the problem--the BNF to abstract syntax tree (AST) parse step--and introduce the novel solution we discovered: a new family of 2D programming langu...

  3. 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

  4. Utilization of nitrogen fixing trees

    Energy Technology Data Exchange (ETDEWEB)

    Brewbaker, J.L.; Beldt, R. van den; MacDicken, K.; Budowski, G.; Kass, D.C.L.; Russo, R.O.; Escalante, G.; Herrera, R.; Aranguren, J.; Arkcoll, D.B.; Doebereinger, J. (cord.)

    1983-01-01

    Six papers from the symposium are noted. Brewbaker, J.L., Beldt, R. van den, MacDicken, K. Fuelwood uses and properties of nitrogen-fixing trees, pp 193-204, (Refs. 15). Includes a list of 35 nitrogen-fixing trees of high fuelwood value. Budowski, G.; Kass, D.C.L.; Russo, R.O. Leguminous trees for shade, pp 205-222, (Refs. 68). Escalante, G., Herrera, R., Aranguren, J.; Nitrogen fixation in shade trees (Erythrina poeppigiana) in cocoa plantations in northern Venezuela, pp 223-230, (Refs. 13). Arkcoll, D.B.; Some leguminous trees providing useful fruits in the North of Brazil, pp 235-239, (Refs. 13). This paper deals with Parkia platycephala, Pentaclethra macroloba, Swartzia sp., Cassia leiandra, Hymenaea courbaril, dipteryz odorata, Inga edulis, I. macrophylla, and I. cinnamonea. Baggio, A.J.; Possibilities of the use of Gliricidia sepium in agroforestry systems in Brazil, pp 241-243; (Refs. 15). Seiffert, N.F.; Biological nitrogen and protein production of Leucaena cultivars grown to supplement the nutrition of ruminants, pp 245-249, (Refs. 14). Leucaena leucocephala cv. Peru, L. campina grande (L. leucocephala), and L. cunningham (L. leucocephalae) were promising for use as browse by beef cattle in central Brazil.

  5. 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 (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.

  6. Automated Generation of Attack Trees

    DEFF Research Database (Denmark)

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

    2014-01-01

    Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error-prone and impractica......Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error......-prone and impracticable for large systems. Nonetheless, the automated generation of attack trees has only been explored in connection to computer networks and levering rich models, whose analysis typically leads to an exponential blow-up of the state space. We propose a static analysis approach where attack trees...... 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...

  7. Sudden Oak Death-Induced Tanoak Mortality in Coast Redwood Forests: Current and Predicted Impacts to Stand Structure

    Directory of Open Access Journals (Sweden)

    Kevin L. O’Hara

    2010-08-01

    Full Text Available Tanoak (Notholithocarpus densiflorus syn. Lithocarpus densiflorus is one of the most widespread and abundant associates of coast redwood (Sequoia sempervirens, but little is known about the structural relationships between these two species. Knowledge of such relationships is essential for a thorough understanding of the impacts of sudden oak death (caused by the exotic pathogen Phytophthora ramorum, which is currently decimating tanoak populations throughout the redwood range. In this study, we utilized a stratified plot design and a stand reconstruction technique to assess structural impacts, at present and in the future, of this emerging disease. We found that residual trees in diseased plots were more aggregated than trees in unaffected plots, and we predicted that the loss of tanoak will lead to the following short-term changes: greater average diameter, height, height-to-live-crown, and crown length, as well as an increase in average nearest neighbor differences for diameter, height, and crown length. In addition, plots lacking tanoak (living or dead—as compared to plots with tanoak—exhibited greater average diameter and increased nearest neighbor differences with regard to diameter, height, and crown length. We also conducted a preliminary exploration of how sudden oak death-induced structural changes compare with typical old-growth characteristics, and how this disease may affect the structure of old-growth forests.

  8. Drawing Contour Trees in the Plane.

    Science.gov (United States)

    Heine, C; Schneider, D; Carr, Hamish; Scheuermann, G

    2011-11-01

    The contour tree compactly describes scalar field topology. From the viewpoint of graph drawing, it is a tree with attributes at vertices and optionally on edges. Standard tree drawing algorithms emphasize structural properties of the tree and neglect the attributes. Applying known techniques to convey this information proves hard and sometimes even impossible. We present several adaptions of popular graph drawing approaches to the problem of contour tree drawing and evaluate them. We identify five esthetic criteria for drawing contour trees and present a novel algorithm for drawing contour trees in the plane that satisfies four of these criteria. Our implementation is fast and effective for contour tree sizes usually used in interactive systems (around 100 branches) and also produces readable pictures for larger trees, as is shown for an 800 branch example.

  9. Totally optimal decision trees for Boolean functions

    KAUST Repository

    Chikalov, Igor

    2016-07-28

    We study decision trees which are totally optimal relative to different sets of complexity parameters for Boolean functions. A totally optimal tree is an optimal tree relative to each parameter from the set simultaneously. We consider the parameters characterizing both time (in the worst- and average-case) and space complexity of decision trees, i.e., depth, total path length (average depth), and number of nodes. We have created tools based on extensions of dynamic programming to study totally optimal trees. These tools are applicable to both exact and approximate decision trees, and allow us to make multi-stage optimization of decision trees relative to different parameters and to count the number of optimal trees. Based on the experimental results we have formulated the following hypotheses (and subsequently proved): for almost all Boolean functions there exist totally optimal decision trees (i) relative to the depth and number of nodes, and (ii) relative to the depth and average depth.

  10. Integrated fault tree development environment

    International Nuclear Information System (INIS)

    Dixon, B.W.

    1986-01-01

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

  11. Interpreting the universal phylogenetic tree

    Science.gov (United States)

    Woese, C. R.

    2000-01-01

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

  12. Columnar apple tree named 'Moonlight'

    OpenAIRE

    Tupý, J. (Jaroslav); Louda, O. (Otto); Zima, J. (Jan)

    2010-01-01

    A new and distinct Malus domestica (Borkh.) apple tree variety is provided which exhibits a columnar tree type, weakly vigorous compact growth, predominant bearing on spurs and V.sub.f-resistance against scab. The new variety yields late maturing, medium-sized, globose-conical to conical fruits having good storage quality. The fruit color is yellow-green to yellow with a partial red to orange blush. The fruits have a yellow-colored firm flesh that is crisp and juicy with a good sweet/sour bal...

  13. Interpreting CNNs via Decision Trees

    OpenAIRE

    Zhang, Quanshi; Yang, Yu; Wu, Ying Nian; Zhu, Song-Chun

    2018-01-01

    This paper presents a method to learn a decision tree to quantitatively explain the logic of each prediction of a pre-trained convolutional neural networks (CNNs). Our method boosts the following two aspects of network interpretability. 1) In the CNN, each filter in a high conv-layer must represent a specific object part, instead of describing mixed patterns without clear meanings. 2) People can explain each specific prediction made by the CNN at the semantic level using a decision tree, i.e....

  14. Usefulness of problem tree, objective tree and logical framework ...

    African Journals Online (AJOL)

    The discussion has led to the conclusion that higher learning institutions are not adequately preparing graduates to face the increasing labor market demands in terms of skills and competitiveness. Having outlined the roots of the problem through the problem tree, the researchers proposed potential strategies to handle the ...

  15. DLRS: gene tree evolution in light of a species tree.

    Science.gov (United States)

    Sjöstrand, Joel; Sennblad, Bengt; Arvestad, Lars; Lagergren, Jens

    2012-11-15

    PrIME-DLRS (or colloquially: 'Delirious') is a phylogenetic software tool to simultaneously infer and reconcile a gene tree given a species tree. It accounts for duplication and loss events, a relaxed molecular clock and is intended for the study of homologous gene families, for example in a comparative genomics setting involving multiple species. PrIME-DLRS uses a Bayesian MCMC framework, where the input is a known species tree with divergence times and a multiple sequence alignment, and the output is a posterior distribution over gene trees and model parameters. PrIME-DLRS is available for Java SE 6+ under the New BSD License, and JAR files and source code can be downloaded from http://code.google.com/p/jprime/. There is also a slightly older C++ version available as a binary package for Ubuntu, with download instructions at http://prime.sbc.su.se. The C++ source code is available upon request. joel.sjostrand@scilifelab.se or jens.lagergren@scilifelab.se. PrIME-DLRS is based on a sound probabilistic model (Åkerborg et al., 2009) and has been thoroughly validated on synthetic and biological datasets (Supplementary Material online).

  16. 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…

  17. Integrating cyber attacks within fault trees

    International Nuclear Information System (INIS)

    Nai Fovino, Igor; Masera, Marcelo; De Cian, Alessio

    2009-01-01

    In this paper, a new method for quantitative security risk assessment of complex systems is presented, combining fault-tree analysis, traditionally used in reliability analysis, with the recently introduced Attack-tree analysis, proposed for the study of malicious attack patterns. The combined use of fault trees and attack trees helps the analyst to effectively face the security challenges posed by the introduction of modern ICT technologies in the control systems of critical infrastructures. The proposed approach allows considering the interaction of malicious deliberate acts with random failures. Formal definitions of fault tree and attack tree are provided and a mathematical model for the calculation of system fault probabilities is presented.

  18. 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.

  19. On Tree-Based Phylogenetic Networks.

    Science.gov (United States)

    Zhang, Louxin

    2016-07-01

    A large class of phylogenetic networks can be obtained from trees by the addition of horizontal edges between the tree edges. These networks are called tree-based networks. We present a simple necessary and sufficient condition for tree-based networks and prove that a universal tree-based network exists for any number of taxa that contains as its base every phylogenetic tree on the same set of taxa. This answers two problems posted by Francis and Steel recently. A byproduct is a computer program for generating random binary phylogenetic networks under the uniform distribution model.

  20. 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.

  1. Integrating cyber attacks within fault trees

    Energy Technology Data Exchange (ETDEWEB)

    Nai Fovino, Igor [Joint Research Centre - EC, Institute for the Protection and Security of the Citizen, Ispra, VA (Italy)], E-mail: igor.nai@jrc.it; Masera, Marcelo [Joint Research Centre - EC, Institute for the Protection and Security of the Citizen, Ispra, VA (Italy); De Cian, Alessio [Department of Electrical Engineering, University di Genova, Genoa (Italy)

    2009-09-15

    In this paper, a new method for quantitative security risk assessment of complex systems is presented, combining fault-tree analysis, traditionally used in reliability analysis, with the recently introduced Attack-tree analysis, proposed for the study of malicious attack patterns. The combined use of fault trees and attack trees helps the analyst to effectively face the security challenges posed by the introduction of modern ICT technologies in the control systems of critical infrastructures. The proposed approach allows considering the interaction of malicious deliberate acts with random failures. Formal definitions of fault tree and attack tree are provided and a mathematical model for the calculation of system fault probabilities is presented.

  2. Recursive algorithms for phylogenetic tree counting.

    Science.gov (United States)

    Gavryushkina, Alexandra; Welch, David; Drummond, Alexei J

    2013-10-28

    In Bayesian phylogenetic inference we are interested in distributions over a space of trees. The number of trees in a tree space is an important characteristic of the space and is useful for specifying prior distributions. When all samples come from the same time point and no prior information available on divergence times, the tree counting problem is easy. However, when fossil evidence is used in the inference to constrain the tree or data are sampled serially, new tree spaces arise and counting the number of trees is more difficult. We describe an algorithm that is polynomial in the number of sampled individuals for counting of resolutions of a constraint tree assuming that the number of constraints is fixed. We generalise this algorithm to counting resolutions of a fully ranked constraint tree. We describe a quadratic algorithm for counting the number of possible fully ranked trees on n sampled individuals. We introduce a new type of tree, called a fully ranked tree with sampled ancestors, and describe a cubic time algorithm for counting the number of such trees on n sampled individuals. These algorithms should be employed for Bayesian Markov chain Monte Carlo inference when fossil data are included or data are serially sampled.

  3. A Metric on Phylogenetic Tree Shapes.

    Science.gov (United States)

    Colijn, C; Plazzotta, G

    2018-01-01

    The shapes of evolutionary trees are influenced by the nature of the evolutionary process but comparisons of trees from different processes are hindered by the challenge of completely describing tree shape. We present a full characterization of the shapes of rooted branching trees in a form that lends itself to natural tree comparisons. We use this characterization to define a metric, in the sense of a true distance function, on tree shapes. The metric distinguishes trees from random models known to produce different tree shapes. It separates trees derived from tropical versus USA influenza A sequences, which reflect the differing epidemiology of tropical and seasonal flu. We describe several metrics based on the same core characterization, and illustrate how to extend the metric to incorporate trees' branch lengths or other features such as overall imbalance. Our approach allows us to construct addition and multiplication on trees, and to create a convex metric on tree shapes which formally allows computation of average tree shapes. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  4. TreePOD: Sensitivity-Aware Selection of Pareto-Optimal Decision Trees.

    Science.gov (United States)

    Muhlbacher, Thomas; Linhardt, Lorenz; Moller, Torsten; Piringer, Harald

    2018-01-01

    Balancing accuracy gains with other objectives such as interpretability is a key challenge when building decision trees. However, this process is difficult to automate because it involves know-how about the domain as well as the purpose of the model. This paper presents TreePOD, a new approach for sensitivity-aware model selection along trade-offs. TreePOD is based on exploring a large set of candidate trees generated by sampling the parameters of tree construction algorithms. Based on this set, visualizations of quantitative and qualitative tree aspects provide a comprehensive overview of possible tree characteristics. Along trade-offs between two objectives, TreePOD provides efficient selection guidance by focusing on Pareto-optimal tree candidates. TreePOD also conveys the sensitivities of tree characteristics on variations of selected parameters by extending the tree generation process with a full-factorial sampling. We demonstrate how TreePOD supports a variety of tasks involved in decision tree selection and describe its integration in a holistic workflow for building and selecting decision trees. For evaluation, we illustrate a case study for predicting critical power grid states, and we report qualitative feedback from domain experts in the energy sector. This feedback suggests that TreePOD enables users with and without statistical background a confident and efficient identification of suitable decision trees.

  5. Identifying the rooted species tree from the distribution of unrooted gene trees under the coalescent.

    Science.gov (United States)

    Allman, Elizabeth S; Degnan, James H; Rhodes, John A

    2011-06-01

    Gene trees are evolutionary trees representing the ancestry of genes sampled from multiple populations. Species trees represent populations of individuals-each with many genes-splitting into new populations or species. The coalescent process, which models ancestry of gene copies within populations, is often used to model the probability distribution of gene trees given a fixed species tree. This multispecies coalescent model provides a framework for phylogeneticists to infer species trees from gene trees using maximum likelihood or Bayesian approaches. Because the coalescent models a branching process over time, all trees are typically assumed to be rooted in this setting. Often, however, gene trees inferred by traditional phylogenetic methods are unrooted. We investigate probabilities of unrooted gene trees under the multispecies coalescent model. We show that when there are four species with one gene sampled per species, the distribution of unrooted gene tree topologies identifies the unrooted species tree topology and some, but not all, information in the species tree edges (branch lengths). The location of the root on the species tree is not identifiable in this situation. However, for 5 or more species with one gene sampled per species, we show that the distribution of unrooted gene tree topologies identifies the rooted species tree topology and all its internal branch lengths. The length of any pendant branch leading to a leaf of the species tree is also identifiable for any species from which more than one gene is sampled.

  6. GumTree: Data reduction

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, Hugh [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)]. E-mail: hrz@ansto.gov.au; Hathaway, Paul [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Hauser, Nick [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Fei, Yang [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Franceschini, Ferdi [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Lam, Tony [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    2006-11-15

    Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation.

  7. Tree value conversion standards revisited

    Science.gov (United States)

    Paul S. DeBald; Martin E. Dale; Martin E. Dale

    1991-01-01

    Updated tree value conversion standards (TVCS) are presented for 12 important hardwood species of the oak-hickory forest. These updated standards-developed for each species by butt-log grade, merchantable height, and diameter at breast height-reflect the changes in lumber prices and in conversion costs which have occurred since 1976 when the original TVCS were...

  8. Induction of Ordinal Decision Trees

    NARCIS (Netherlands)

    J.C. Bioch (Cor); V. Popova (Viara)

    2003-01-01

    textabstractThis paper focuses on the problem of monotone decision trees from the point of view of the multicriteria decision aid methodology (MCDA). By taking into account the preferences of the decision maker, an attempt is made to bring closer similar research within machine learning and MCDA.

  9. Are there tides within trees?

    Science.gov (United States)

    Fisahn, Joachim

    2018-01-24

    Tree stem diameters and electrical stem potentials exhibit rhythmic variations with periodicities of 24-25 h. Under free-running conditions of constant light or darkness these rhythms were suggested to be mediated by the lunisolar gravitational force. To further unravel the regulation of tree stem diameter dilatations, many of the published time courses of diameter variations were re-evaluated in conjunction with the contemporaneous time courses of the lunisolar tidal acceleration. This was accomplished by application of the Etide program, which estimates, with high temporal resolution, local gravitational changes as a consequence of the diurnal variations of the lunisolar gravitational force due to the orbits and relative positions of Earth, Moon and Sun. In all instances investigated, it was evident that a synchronism exists between the times of the turning points of both the lunisolar tide and stem diameter variations when the direction of extension changes. This finding of synchrony documents that the lunisolar tide is a regulator of the tree stem diameter dilatations. Under the described experimental conditions, rhythms in tree stem diameter dilations and electrical stem potentials are controlled by the lunisolar gravitational acceleration. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Tree improvement and environmental forestry

    Science.gov (United States)

    Warren T. Doolittle

    1971-01-01

    I was invited to talk to you about some of the things tree improvement can do to help our forest environment. Now I do not claim to have a corner on the market for ideas that geneticists can use in our environment, and I know that a number of scholarly papers have been presented previously on this subject.

  11. Eucalyptus as a landscape tree

    Science.gov (United States)

    W. Douglas Hamilton

    1983-01-01

    Ninety-two species of Eucalyptus were evaluated at the University of California re- search station in San Jose. The purpose: to find acceptable new street and park trees. Growth rates and horticultural characteristics were noted. Forty-three species were studied in locations statewide to evaluate site adaptation and landscape usefulness; flooded, cold, dry, saline....

  12. A Distributed Spanning Tree Algorithm

    DEFF Research Database (Denmark)

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

    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...

  13. 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)…

  14. 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.

  15. Wellhead and tree standards updated

    International Nuclear Information System (INIS)

    Dach, A.J. Jr.; Haeberle, T.

    1996-01-01

    Revisions in the API 6A, 17th Edition, have resolved a number of long-term problems and expanded its scope and coverage of wellhead and christmas tree equipment. The 17th Edition, Feb. 1, 1996, represents the state-of-the-art in international requirements for wellhead and christmas tree equipment. The design, materials, and quality control aspects of API 6A have all been improved with an emphasis on making the document more acceptable around the world. However, there are unresolved issues that raise many questions about the future direction of efforts aimed at international standardization of wellhead and christmas tree equipment. Unfortunately, these unresolved issues confuse both manufacturers and companies purchasing this equipment. This ultimately increases wellhead and christmas tree costs, so it is to everyone's advantage to resolve these issues. This article describes the significant revisions that are included in API 6A, 17th Edition. Also discussed are the regulatory, standardization, and customer acceptance issues that cloud the future of API 6A, 17th Edition

  16. 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…

  17. GumTree: Data reduction

    International Nuclear Information System (INIS)

    Rayner, Hugh; Hathaway, Paul; Hauser, Nick; Fei, Yang; Franceschini, Ferdi; Lam, Tony

    2006-01-01

    Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation

  18. 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

  19. 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…

  20. Top tips from tree tops

    Science.gov (United States)

    Ornes, Stephen

    2018-04-01

    The ability of trees to cool by transporting water from their roots to the leaves has been known for centuries. But as Stephen Ornes discovers, the principles of transpiration are also inspiring innovative techniques to cool vehicles travelling at hypersonic speeds, where unwanted heat is a problem too

  1. 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 as comm...

  2. 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...

  3. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sö ren; Jarząbek, Michał; Hadrich, Torsten; Michels, Dominik L.; Palubicki, Wojciech

    2017-01-01

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical

  4. EDITORIAL Development Linkages between Tree Breeding ...

    African Journals Online (AJOL)

    EDITORIAL Development Linkages between Tree Breeding Programmes and National/Regional Tree Seed Centres in Africa. ... Discovery and Innovation. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives.

  5. Systolic automata for VLSI on balanced trees

    Energy Technology Data Exchange (ETDEWEB)

    Culik, K Ii; Gruska, J; Salomaa, A

    1983-01-01

    Systolic tree automata with a binary (or, more generally, balanced) underlying tree are investigated. The main emphasis is on input conditions, decidability, and characterization of acceptable languages. 4 references.

  6. 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

  7. Computing Refined Buneman Trees in Cubic Time

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... 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...

  8. Understanding search trees via statistical physics

    Indian Academy of Sciences (India)

    ary search tree model (where stands for the number of branches of the search tree), an important problem for data storage in computer science, using a variety of statistical physics techniques that allow us to obtain exact asymptotic results.

  9. Tree rings and radiocarbon calibration

    International Nuclear Information System (INIS)

    Barbetti, M.

    1999-01-01

    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond

  10. A Durable Flash Memory Search Tree

    OpenAIRE

    Clay III, James; Wortman, Kevin

    2012-01-01

    We consider the task of optimizing the B-tree data structure, used extensively in operating systems and databases, for sustainable usage on multi-level flash memory. Empirical evidence shows that this new flash memory tree, or FM Tree, extends the operational lifespan of each block of flash memory by a factor of roughly 27 to 70 times, while still supporting logarithmic-time search tree operations.

  11. Using tree diversity to compare phylogenetic heuristics.

    Science.gov (United States)

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

    2009-04-29

    Evolutionary trees are family trees that represent the relationships between a group of organisms. Phylogenetic heuristics are used to search stochastically for the best-scoring trees in tree space. Given that better tree scores are believed to be better approximations of the true phylogeny, traditional evaluation techniques have used tree scores to determine the heuristics that find the best scores in the fastest time. We develop new techniques to evaluate phylogenetic heuristics based on both tree scores and topologies to compare Pauprat and Rec-I-DCM3, two popular Maximum Parsimony search algorithms. Our results show that although Pauprat and Rec-I-DCM3 find the trees with the same best scores, topologically these trees are quite different. Furthermore, the Rec-I-DCM3 trees cluster distinctly from the Pauprat trees. In addition to our heatmap visualizations of using parsimony scores and the Robinson-Foulds distance to compare best-scoring trees found by the two heuristics, we also develop entropy-based methods to show the diversity of the trees found. Overall, Pauprat identifies more diverse trees than Rec-I-DCM3. Overall, our work shows that there is value to comparing heuristics beyond the parsimony scores that they find. Pauprat is a slower heuristic than Rec-I-DCM3. However, our work shows that there is tremendous value in using Pauprat to reconstruct trees-especially since it finds identical scoring but topologically distinct trees. Hence, instead of discounting Pauprat, effort should go in improving its implementation. Ultimately, improved performance measures lead to better phylogenetic heuristics and will result in better approximations of the true evolutionary history of the organisms of interest.

  12. Locating a tree in a phylogenetic network

    OpenAIRE

    van Iersel, Leo; Semple, Charles; Steel, Mike

    2010-01-01

    Phylogenetic trees and networks are leaf-labelled graphs that are used to describe evolutionary histories of species. The Tree Containment problem asks whether a given phylogenetic tree is embedded in a given phylogenetic network. Given a phylogenetic network and a cluster of species, the Cluster Containment problem asks whether the given cluster is a cluster of some phylogenetic tree embedded in the network. Both problems are known to be NP-complete in general. In this article, we consider t...

  13. The transposition distance for phylogenetic trees

    OpenAIRE

    Rossello, Francesc; Valiente, Gabriel

    2006-01-01

    The search for similarity and dissimilarity measures on phylogenetic trees has been motivated by the computation of consensus trees, the search by similarity in phylogenetic databases, and the assessment of clustering results in bioinformatics. The transposition distance for fully resolved phylogenetic trees is a recent addition to the extensive collection of available metrics for comparing phylogenetic trees. In this paper, we generalize the transposition distance from fully resolved to arbi...

  14. 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.

  15. The national tree-list layer

    Science.gov (United States)

    Stacy A. Drury; Jason M. Herynk

    2011-01-01

    The National Tree-List Layer (NTLL) project used LANDFIRE map products to produce the first national tree-list map layer that represents tree populations at stand and regional levels. The NTLL was produced in a short time frame to address the needs of Fire and Aviation Management for a map layer that could be used as input for simulating fire-caused tree mortality...

  16. Millennium-scale crossdating and inter-annual climate sensitivities of standing California redwoods.

    Science.gov (United States)

    Carroll, Allyson L; Sillett, Stephen C; Kramer, Russell D

    2014-01-01

    Extremely decay-resistant wood and fire-resistant bark allow California's redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI) helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE) have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood species have

  17. Millennium-scale crossdating and inter-annual climate sensitivities of standing California redwoods.

    Directory of Open Access Journals (Sweden)

    Allyson L Carroll

    Full Text Available Extremely decay-resistant wood and fire-resistant bark allow California's redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood

  18. On Tree-Constrained Matchings and Generalizations

    NARCIS (Netherlands)

    S. Canzar (Stefan); K. Elbassioni; G.W. Klau (Gunnar); J. Mestre

    2011-01-01

    htmlabstractWe consider the following \\textsc{Tree-Constrained Bipartite Matching} problem: Given two rooted trees $T_1=(V_1,E_1)$, $T_2=(V_2,E_2)$ and a weight function $w: V_1\\times V_2 \\mapsto \\mathbb{R}_+$, find a maximum weight matching $\\mathcal{M}$ between nodes of the two trees, such that

  19. Measuring and analyzing urban tree cover

    Science.gov (United States)

    David J. Nowak; Rowan A. Rowntree; E. Gregory McPherson; Susan M. Sisinni; Esther R. Kirkmann; Jack C. Stevens

    1996-01-01

    Measurement of city tree cover can aid in urban vegetation planning, management, and research by revealing characteristics of vegetation across a city. Urban tree cover in the United States ranges from 0.4% in Lancaster, California, to 55% in Baton Rouge, Louisiana. Two important factors that affect the amount of urban tree cover are the natural environment and land...

  20. Understanding the challenges of municipal tree planting

    Science.gov (United States)

    E.G. McPherson; R. Young

    2010-01-01

    Nine of the twelve largest cities in the U.S. have mayoral tree planting initiatives (TPIs), with pledges to plant nearly 20 million trees. Although executive-level support for trees has never been this widespread, many wonder if this support will endure as administrations change and budgets tighten. In an effort to share lessons learned from successes and setbacks, a...

  1. THE CONTRIBUTION OF AGROFORESTRY TREE PRODUCTS TO ...

    African Journals Online (AJOL)

    philiph

    contribution of agro-forestry tree products to the livelihood of rural farmers was high and accounted for ... systems in which trees are grown with ... livelihood of farmers in rural areas and .... pulp, the seed are boiled in water and dried .... treatment of fracture/dislocation of bones. Some agroforestry trees that provides the rural ...

  2. Sampling the quality of hardwood trees

    Science.gov (United States)

    Adrian M. Gilbert

    1959-01-01

    Anyone acquainted with the conversion of hardwood trees into wood products knows that timber has a wide range in quality. Some trees will yield better products than others. So, in addition to rate of growth and size, tree values are affected by the quality of products yielded.

  3. Locating a tree in a phylogenetic network

    NARCIS (Netherlands)

    Iersel, van L.J.J.; Semple, C.; Steel, M.A.

    2010-01-01

    Phylogenetic trees and networks are leaf-labelled graphs that are used to describe evolutionary histories of species. The Tree Containment problem asks whether a given phylogenetic tree is embedded in a given phylogenetic network. Given a phylogenetic network and a cluster of species, the Cluster

  4. Finding small equivalent decision trees is hard

    NARCIS (Netherlands)

    Zantema, H.; Bodlaender, H.L.

    2000-01-01

    Two decision trees are called decision equivalent if they represent the same function, i.e., they yield the same result for every possible input. We prove that given a decision tree and a number, to decide if there is a decision equivalent decision tree of size at most that number is NPcomplete. As

  5. Which trees should be removed in thinning?

    Directory of Open Access Journals (Sweden)

    Timo Pukkala

    2015-12-01

    Full Text Available Background: In economically optimal management, trees that are removed in a thinning treatment should be selected on the basis of their value, relative value increment and the effect of removal on the growth of remaining trees. Large valuable trees with decreased value increment should be removed, especially when they overtop smaller trees. Methods: This study optimized the tree selection rule in the thinning treatments of continuous cover management when the aim is to maximize the profitability of forest management. The weights of three criteria (stem value, relative value increment and effect of removal on the competition of remaining trees were optimized together with thinning intervals. Results and conclusions: The results confirmed the hypothesis that optimal thinning involves removing predominantly large trees. Increasing stumpage value, decreasing relative value increment, and increasing competitive influence increased the likelihood that removal is optimal decision. However, if the spatial distribution of trees is irregular, it is optimal to leave large trees in sparse places and remove somewhat smaller trees from dense places. However, the benefit of optimal thinning, as compared to diameter limit cutting is not usually large in pure one-species stands. On the contrary, removing the smallest trees from the stand may lead to significant (30–40 % reductions in the net present value of harvest incomes. Keywords: Continuous cover forestry, Tree selection, High thinning, Optimal management, Spatial distribution, Spatial growth model

  6. Aspects of insertion in random trees

    NARCIS (Netherlands)

    Bagchi, Arunabha; Reingold, E.M.

    1982-01-01

    A method formulated by Yao and used by Brown has yielded bounds on the fraction of nodes with specified properties in trees bult by a sequence of random internal nodes in a random tree built by binary search and insertion, and show that in such a tree about bounds better than those now known. We

  7. Coalescent methods for estimating phylogenetic trees.

    Science.gov (United States)

    Liu, Liang; Yu, Lili; Kubatko, Laura; Pearl, Dennis K; Edwards, Scott V

    2009-10-01

    We review recent models to estimate phylogenetic trees under the multispecies coalescent. Although the distinction between gene trees and species trees has come to the fore of phylogenetics, only recently have methods been developed that explicitly estimate species trees. Of the several factors that can cause gene tree heterogeneity and discordance with the species tree, deep coalescence due to random genetic drift in branches of the species tree has been modeled most thoroughly. Bayesian approaches to estimating species trees utilizes two likelihood functions, one of which has been widely used in traditional phylogenetics and involves the model of nucleotide substitution, and the second of which is less familiar to phylogeneticists and involves the probability distribution of gene trees given a species tree. Other recent parametric and nonparametric methods for estimating species trees involve parsimony criteria, summary statistics, supertree and consensus methods. Species tree approaches are an appropriate goal for systematics, appear to work well in some cases where concatenation can be misleading, and suggest that sampling many independent loci will be paramount. Such methods can also be challenging to implement because of the complexity of the models and computational time. In addition, further elaboration of the simplest of coalescent models will be required to incorporate commonly known issues such as deviation from the molecular clock, gene flow and other genetic forces.

  8. Evaluating realized genetic gains from tree improvement.

    Science.gov (United States)

    J.B. St. Clair

    1993-01-01

    Tree improvement has become an essential part of the management of forest lands for wood production, and predicting yields and realized gains from forests planted with genetically-improved trees will become increasingly important. This paper discusses concepts of tree improvement and genetic gain important to growth and yield modeling, and reviews previous studies of...

  9. A practical alternative to single tree selection?

    Science.gov (United States)

    Gary W. Miller; H. Clay Smith

    1993-01-01

    When landowners want to develop and maintain an uneven-aged tree structure in eastern hardwood stands, single-tree selection often is suggested as the only advisable, long-term partial regeneration harvest method. Single-tree selection is preferred because it provides a means for improving quality and controlling stocking of the residual stand necessary for sustained...

  10. Do you believe in palm trees?

    Science.gov (United States)

    Kevin T. Smith

    2013-01-01

    Palms are real, but are they really trees? The answer depends on definitions. As usually tall, peremrial plants with roots, stems, and leaves, palms seem to qualify. Palms should also qualify because arborists care for them, and arborists care for trees, right? My introduction to botany class defined trees as plants that produce wood. Unraveling the question of whether...

  11. Carbon dynamics in trees: feast or famine?

    Science.gov (United States)

    Anna Sala; David R. Woodruff; Fredrick C. Meinzer

    2012-01-01

    Research on the degree to which carbon (C) availability limits growth in trees, as well as recent trends in climate change and concurrent increases in drought related tree mortality, have led to a renewed focus on the physiological mechanisms associated with tree growth responses to current and future climate. This has led to some dispute over the role of stored...

  12. 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

  13. Per tree estimates with n-tree distance sampling: an application to increment core data

    Science.gov (United States)

    Thomas B. Lynch; Robert F. Wittwer

    2002-01-01

    Per tree estimates using the n trees nearest a point can be obtained by using a ratio of per unit area estimates from n-tree distance sampling. This ratio was used to estimate average age by d.b.h. classes for cottonwood trees (Populus deltoides Bartr. ex Marsh.) on the Cimarron National Grassland. Increment...

  14. 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...

  15. Monitoring Million Trees LA: Tree performance during the early years and future benefits

    Science.gov (United States)

    E. Gregory McPherson

    2014-01-01

    Million Trees LA (MTLA) is one of several large-scale mayoral tree planting initiatives striving to create more livable cities through urban forestry. This study combined field sampling of tree survival and growth with numerical modeling of future benefits to assess performance of MTLA plantings. From 2006 to 2010 MTLA planted a diverse mix of 91,786 trees....

  16. DupTree: a program for large-scale phylogenetic analyses using gene tree parsimony.

    Science.gov (United States)

    Wehe, André; Bansal, Mukul S; Burleigh, J Gordon; Eulenstein, Oliver

    2008-07-01

    DupTree is a new software program for inferring rooted species trees from collections of gene trees using the gene tree parsimony approach. The program implements a novel algorithm that significantly improves upon the run time of standard search heuristics for gene tree parsimony, and enables the first truly genome-scale phylogenetic analyses. In addition, DupTree allows users to examine alternate rootings and to weight the reconciliation costs for gene trees. DupTree is an open source project written in C++. DupTree for Mac OS X, Windows, and Linux along with a sample dataset and an on-line manual are available at http://genome.cs.iastate.edu/CBL/DupTree

  17. FastTree: Computing Large Minimum Evolution Trees with Profiles instead of a Distance Matrix

    OpenAIRE

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

    2009-01-01

    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 in...

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

    Science.gov (United States)

    2013-01-01

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

  19. 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 average accuracy for the center point estimation is 0.2 m in the along track direction and 0.35 m in the across track direction. The goal of the tree mapping algorithm is create a database of individual trees, and be the basis for creation of a graph map that can be used for mission planning...

  20. Computer aided construction of fault tree

    International Nuclear Information System (INIS)

    Kovacs, Z.

    1982-01-01

    Computer code CAT for the automatic construction of the fault tree is briefly described. Code CAT makes possible simple modelling of components using decision tables, it accelerates the fault tree construction process, constructs fault trees of different complexity, and is capable of harmonized co-operation with programs PREPandKITT 1,2 for fault tree analysis. The efficiency of program CAT and thus the accuracy and completeness of fault trees constructed significantly depends on the compilation and sophistication of decision tables. Currently, program CAT is used in co-operation with programs PREPandKITT 1,2 in reliability analyses of nuclear power plant systems. (B.S.)

  1. Air pollution and tree growth

    Energy Technology Data Exchange (ETDEWEB)

    Scurfield, G

    1960-01-01

    The problem of air pollution is reviewed with emphasis on its origin and its effects on trees and shrubs. These effects are described from two points of view: the effects of general air pollution, and also the effects of specific pollutants. The considerable mixing, dilution and interaction that pollutants undergo in the air often renders it exceedingly difficult to assign pollution damage to any specific chemical or physical entity. Moreover, it is often impossible to assign responsibility for damage to any particular source. The constituents of general air pollution may be subdivided into those potentially incapable, and those potentially capable, of entering the plant either through the leaf stomata or indirectly by way of the soil. Specific pollutants cause damage directly, as well as indirectly from the chemical reactions that occur in the polluted atmosphere. Sulfur dioxide is discussed in detail in relation to tree and shrub damage, with numerous examples of plant injuries.

  2. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    Attribute clustering has been previously employed to detect statistical dependence between subsets of variables. We propose a novel attribute clustering algorithm motivated by research of complex networks, called the Star Discovery algorithm. The algorithm partitions and indirectly discards...... 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...

  3. Carbon Sequestration by Urban Trees

    DEFF Research Database (Denmark)

    Fares, Silvano; Paoletti, Elena; Calfapietra, Carlo

    2017-01-01

    Carbon dioxide (CO2) is the most prominent component of anthropogenic greenhouse gas emissions, resulting mainly from fuel combustion in the built environment – for activities such as heating of buildings, urban mobility and cooking. The concentration of near-surface CO2 in cities is affected by ....... In this chapter, we review the most recent studies and highlight emerging research needs for a better understanding of present and future roles of urban trees in removing CO2 from the atmosphere....

  4. Chemicals from trees and shrubs

    Energy Technology Data Exchange (ETDEWEB)

    Halloran, G M

    1978-01-01

    The need for finding economically viable alternatives to crude oil is discussed in the context of Australia's uncertain reserves of black coal, from which crude oil derivatives may have to be obtained when oil supplies become depleted. A table is presented showing the major fractions of crude oil and the likely sources (in general terms) of equivalent substances from forest trees, shrubs and agricultural species.

  5. 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...

  6. Rooted triple consensus and anomalous gene trees

    Directory of Open Access Journals (Sweden)

    Schmidt Heiko A

    2008-04-01

    Full Text Available Abstract Background Anomalous gene trees (AGTs are gene trees with a topology different from a species tree that are more probable to observe than congruent gene trees. In this paper we propose a rooted triple approach to finding the correct species tree in the presence of AGTs. Results Based on simulated data we show that our method outperforms the extended majority rule consensus strategy, while still resolving the species tree. Applying both methods to a metazoan data set of 216 genes, we tested whether AGTs substantially interfere with the reconstruction of the metazoan phylogeny. Conclusion Evidence of AGTs was not found in this data set, suggesting that erroneously reconstructed gene trees are the most significant challenge in the reconstruction of phylogenetic relationships among species with current data. The new method does however rule out the erroneous reconstruction of deep or poorly resolved splits in the presence of lineage sorting.

  7. The stopping rules for winsorized tree

    Science.gov (United States)

    Ch'ng, Chee Keong; Mahat, Nor Idayu

    2017-11-01

    Winsorized tree is a modified tree-based classifier that is able to investigate and to handle all outliers in all nodes along the process of constructing the tree. It overcomes the tedious process of constructing a classical tree where the splitting of branches and pruning go concurrently so that the constructed tree would not grow bushy. This mechanism is controlled by the proposed algorithm. In winsorized tree, data are screened for identifying outlier. If outlier is detected, the value is neutralized using winsorize approach. Both outlier identification and value neutralization are executed recursively in every node until predetermined stopping criterion is met. The aim of this paper is to search for significant stopping criterion to stop the tree from further splitting before overfitting. The result obtained from the conducted experiment on pima indian dataset proved that the node could produce the final successor nodes (leaves) when it has achieved the range of 70% in information gain.

  8. Nonbinary Tree-Based Phylogenetic Networks.

    Science.gov (United States)

    Jetten, Laura; van Iersel, Leo

    2018-01-01

    Rooted phylogenetic networks are used to describe evolutionary histories that contain non-treelike evolutionary events such as hybridization and horizontal gene transfer. In some cases, such histories can be described by a phylogenetic base-tree with additional linking arcs, which can, for example, represent gene transfer events. Such phylogenetic networks are called tree-based. Here, we consider two possible generalizations of this concept to nonbinary networks, which we call tree-based and strictly-tree-based nonbinary phylogenetic networks. We give simple graph-theoretic characterizations of tree-based and strictly-tree-based nonbinary phylogenetic networks. Moreover, we show for each of these two classes that it can be decided in polynomial time whether a given network is contained in the class. Our approach also provides a new view on tree-based binary phylogenetic networks. Finally, we discuss two examples of nonbinary phylogenetic networks in biology and show how our results can be applied to them.

  9. Deterministic Automata for Unordered Trees

    Directory of Open Access Journals (Sweden)

    Adrien Boiret

    2014-08-01

    Full Text Available Automata for unordered unranked trees are relevant for defining schemas and queries for data trees in Json or Xml format. While the existing notions are well-investigated concerning expressiveness, they all lack a proper notion of determinism, which makes it difficult to distinguish subclasses of automata for which problems such as inclusion, equivalence, and minimization can be solved efficiently. In this paper, we propose and investigate different notions of "horizontal determinism", starting from automata for unranked trees in which the horizontal evaluation is performed by finite state automata. We show that a restriction to confluent horizontal evaluation leads to polynomial-time emptiness and universality, but still suffers from coNP-completeness of the emptiness of binary intersections. Finally, efficient algorithms can be obtained by imposing an order of horizontal evaluation globally for all automata in the class. Depending on the choice of the order, we obtain different classes of automata, each of which has the same expressiveness as CMso.

  10. Carbon-14 in tree rings

    International Nuclear Information System (INIS)

    Cain, W.F.; Suess, H.E.

    1976-01-01

    In order to investigate how reliably the carbon 14 content of tree rings reflects that of atmospheric carbon dioxide, two types of determinations were carried out: (1) carbon 14 determinations in annual rings from the beginning of this century until 1974 and (2) carbon 14 determinations in synchronous wood from the North American bristlecone pine and from European oak trees, dendrochronologically dated to have grown in the third and fourth century B.C. The first series of measurements showed that bomb-produced radiocarbon was incorporated in wood at a time when it was converted from sapwood to heartwood, whenever radiocarbon from bomb testing was present in the atmosphere. The second series showed that wood more than 2000 years old and grown on two different continents at different altitudes had, within the limits of experimental error, the same radiocarbon content. This work and other experimental evidence, obtained in part by other laboratories, show that tree rings reflect the average radiocarbon content of global atmospheric carbon dioxide accurately within several parts per mil. In rare cases, deviations of up to 10 parts per thousand may be possible. This means that a typical single radiocarbon date for wood or charcoal possesses an intrinsic uncertainty (viz., an estimated ''one-sigma error'' in addition to all the other errors) of the order of +-50 years. This intrinsic uncertainty is independent of the absolute age of the sample. More accurate dates can, in principle, be obtained by the so-called method of ''wiggle matching.''

  11. 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.

  12. 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

  13. Folding and unfolding phylogenetic trees and networks.

    Science.gov (United States)

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

    2016-12-01

    Phylogenetic networks are rooted, labelled directed acyclic graphswhich are commonly used to represent reticulate evolution. There is a close relationship between phylogenetic networks and multi-labelled trees (MUL-trees). Indeed, any phylogenetic network N can be "unfolded" to obtain a MUL-tree U(N) and, conversely, a MUL-tree T can in certain circumstances be "folded" to obtain aphylogenetic network F(T) that exhibits T. In this paper, we study properties of the operations U and F in more detail. In particular, we introduce the class of stable networks, phylogenetic networks N for which F(U(N)) is isomorphic to N, characterise such networks, and show that they are related to the well-known class of tree-sibling networks. We also explore how the concept of displaying a tree in a network N can be related to displaying the tree in the MUL-tree U(N). To do this, we develop aphylogenetic analogue of graph fibrations. This allows us to view U(N) as the analogue of the universal cover of a digraph, and to establish a close connection between displaying trees in U(N) and reconciling phylogenetic trees with networks.

  14. Fuzzy tree automata and syntactic pattern recognition.

    Science.gov (United States)

    Lee, E T

    1982-04-01

    An approach of representing patterns by trees and processing these trees by fuzzy tree automata is described. Fuzzy tree automata are defined and investigated. The results include that the class of fuzzy root-to-frontier recognizable ¿-trees is closed under intersection, union, and complementation. Thus, the class of fuzzy root-to-frontier recognizable ¿-trees forms a Boolean algebra. Fuzzy tree automata are applied to processing fuzzy tree representation of patterns based on syntactic pattern recognition. The grade of acceptance is defined and investigated. Quantitative measures of ``approximate isosceles triangle,'' ``approximate elongated isosceles triangle,'' ``approximate rectangle,'' and ``approximate cross'' are defined and used in the illustrative examples of this approach. By using these quantitative measures, a house, a house with high roof, and a church are also presented as illustrative examples. In addition, three fuzzy tree automata are constructed which have the capability of processing the fuzzy tree representations of ``fuzzy houses,'' ``houses with high roofs,'' and ``fuzzy churches,'' respectively. The results may have useful applications in pattern recognition, image processing, artificial intelligence, pattern database design and processing, image science, and pictorial information systems.

  15. The dynamics of strangling among forest trees.

    Science.gov (United States)

    Okamoto, Kenichi W

    2015-11-07

    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

  16. ETE: a python Environment for Tree Exploration.

    Science.gov (United States)

    Huerta-Cepas, Jaime; Dopazo, Joaquín; Gabaldón, Toni

    2010-01-13

    Many bioinformatics analyses, ranging from gene clustering to phylogenetics, produce hierarchical trees as their main result. These are used to represent the relationships among different biological entities, thus facilitating their analysis and interpretation. A number of standalone programs are available that focus on tree visualization or that perform specific analyses on them. However, such applications are rarely suitable for large-scale surveys, in which a higher level of automation is required. Currently, many genome-wide analyses rely on tree-like data representation and hence there is a growing need for scalable tools to handle tree structures at large scale. Here we present the Environment for Tree Exploration (ETE), a python programming toolkit that assists in the automated manipulation, analysis and visualization of hierarchical trees. ETE libraries provide a broad set of tree handling options as well as specific methods to analyze phylogenetic and clustering trees. Among other features, ETE allows for the independent analysis of tree partitions, has support for the extended newick format, provides an integrated node annotation system and permits to link trees to external data such as multiple sequence alignments or numerical arrays. In addition, ETE implements a number of built-in analytical tools, including phylogeny-based orthology prediction and cluster validation techniques. Finally, ETE's programmable tree drawing engine can be used to automate the graphical rendering of trees with customized node-specific visualizations. ETE provides a complete set of methods to manipulate tree data structures that extends current functionality in other bioinformatic toolkits of a more general purpose. ETE is free software and can be downloaded from http://ete.cgenomics.org.

  17. ETE: a python Environment for Tree Exploration

    Directory of Open Access Journals (Sweden)

    Gabaldón Toni

    2010-01-01

    Full Text Available Abstract Background Many bioinformatics analyses, ranging from gene clustering to phylogenetics, produce hierarchical trees as their main result. These are used to represent the relationships among different biological entities, thus facilitating their analysis and interpretation. A number of standalone programs are available that focus on tree visualization or that perform specific analyses on them. However, such applications are rarely suitable for large-scale surveys, in which a higher level of automation is required. Currently, many genome-wide analyses rely on tree-like data representation and hence there is a growing need for scalable tools to handle tree structures at large scale. Results Here we present the Environment for Tree Exploration (ETE, a python programming toolkit that assists in the automated manipulation, analysis and visualization of hierarchical trees. ETE libraries provide a broad set of tree handling options as well as specific methods to analyze phylogenetic and clustering trees. Among other features, ETE allows for the independent analysis of tree partitions, has support for the extended newick format, provides an integrated node annotation system and permits to link trees to external data such as multiple sequence alignments or numerical arrays. In addition, ETE implements a number of built-in analytical tools, including phylogeny-based orthology prediction and cluster validation techniques. Finally, ETE's programmable tree drawing engine can be used to automate the graphical rendering of trees with customized node-specific visualizations. Conclusions ETE provides a complete set of methods to manipulate tree data structures that extends current functionality in other bioinformatic toolkits of a more general purpose. ETE is free software and can be downloaded from http://ete.cgenomics.org.

  18. Mortality and community changes drive sudden oak death impacts on litterfall and soil nitrogen cycling.

    Science.gov (United States)

    Cobb, Richard C; Eviner, Valerie T; Rizzo, David M

    2013-10-01

    Few studies have quantified pathogen impacts to ecosystem processes, despite the fact that pathogens cause or contribute to regional-scale tree mortality. We measured litterfall mass, litterfall chemistry, and soil nitrogen (N) cycling associated with multiple hosts along a gradient of mortality caused by Phytophthora ramorum, the cause of sudden oak death. In redwood forests, the epidemiological and ecological characteristics of the major overstory species determine disease patterns and the magnitude and nature of ecosystem change. Bay laurel (Umbellularia californica) has high litterfall N (0.992%), greater soil extractable NO3 -N, and transmits infection without suffering mortality. Tanoak (Notholithocarpus densiflorus) has moderate litterfall N (0.723%) and transmits infection while suffering extensive mortality that leads to higher extractable soil NO3 -N. Redwood (Sequoia sempervirens) has relatively low litterfall N (0.519%), does not suffer mortality or transmit the pathogen, but dominates forest biomass. The strongest impact of pathogen-caused mortality was the potential shift in species composition, which will alter litterfall chemistry, patterns and dynamics of litterfall mass, and increase soil NO3 -N availability. Patterns of P. ramorum spread and consequent mortality are closely associated with bay laurel abundances, suggesting this species will drive both disease emergence and subsequent ecosystem function. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

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

    DEFF Research Database (Denmark)

    Li, Heng; Coghlan, Avril; Ruan, Jue

    2006-01-01

    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......, 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...

  20. 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.

  1. Optimal Monotone Drawings of Trees

    OpenAIRE

    He, Dayu; He, Xin

    2016-01-01

    A monotone drawing of a graph G is a straight-line drawing of G such that, for every pair of vertices u,w in G, there exists abpath P_{uw} in G that is monotone in some direction l_{uw}. (Namely, the order of the orthogonal projections of the vertices of P_{uw} on l_{uw} is the same as the order they appear in P_{uw}.) The problem of finding monotone drawings for trees has been studied in several recent papers. The main focus is to reduce the size of the drawing. Currently, the smallest drawi...

  2. Helping to increase tree crops

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1970-07-01

    Tree crops such as coffee, coconuts, palm oil, citrus fruits and cocoa are of major importance to the economies of countries in Africa, Asia and Latin America, and may be a prime source of foreign exchange earnings. The search for ways to improve efficiently the yields of crops like these - now being aided by the Division of Atomic Energy in Food and Agriculture operated jointly with the Food and Agriculture Organization - thus has a clearly defined practical goal. D. Nethsinghe deals here with some of the work. (author)

  3. Helping to increase tree crops

    International Nuclear Information System (INIS)

    1970-01-01

    Tree crops such as coffee, coconuts, palm oil, citrus fruits and cocoa are of major importance to the economies of countries in Africa, Asia and Latin America, and may be a prime source of foreign exchange earnings. The search for ways to improve efficiently the yields of crops like these - now being aided by the Division of Atomic Energy in Food and Agriculture operated jointly with the Food and Agriculture Organization - thus has a clearly defined practical goal. D. Nethsinghe deals here with some of the work. (author)

  4. Whole-tree distribution and temporal variation of non-structural carbohydrates in broadleaf evergreen trees.

    Science.gov (United States)

    Smith, Merryn G; Miller, Rebecca E; Arndt, Stefan K; Kasel, Sabine; Bennett, Lauren T

    2018-04-01

    Non-structural carbohydrates (NSCs) form a fundamental yet poorly quantified carbon pool in trees. Studies of NSC seasonality in forest trees have seldom measured whole-tree NSC stocks and allocation among organs, and are not representative of all tree functional types. Non-structural carbohydrate research has primarily focussed on broadleaf deciduous and coniferous evergreen trees with distinct growing seasons, while broadleaf evergreen trees remain under-studied despite their different growth phenology. We measured whole-tree NSC allocation and temporal variation in Eucalyptus obliqua L'Hér., a broadleaf evergreen tree species typically occurring in mixed-age temperate forests, which has year-round growth and the capacity to resprout after fire. Our overarching objective was to improve the empirical basis for understanding the functional importance of NSC allocation and stock changes at the tree- and organ-level in this tree functional type. Starch was the principal storage carbohydrate and was primarily stored in the stem and roots of young (14-year-old) trees rather than the lignotuber, which did not appear to be a specialized starch storage organ. Whole-tree NSC stocks were depleted during spring and summer due to significant decreases in starch mass in the roots and stem, seemingly to support root and crown growth but potentially exacerbated by water stress in summer. Seasonality of stem NSCs differed between young and mature trees, and was not synchronized with stem basal area increments in mature trees. Our results suggest that the relative magnitude of seasonal NSC stock changes could vary with tree growth stage, and that the main drivers of NSC fluctuations in broadleaf evergreen trees in temperate biomes could be periodic disturbances such as summer drought and fire, rather than growth phenology. These results have implications for understanding post-fire tree recovery via resprouting, and for incorporating NSC pools into carbon models of mixed

  5. TreeNetViz: revealing patterns of networks over tree structures.

    Science.gov (United States)

    Gou, Liang; Zhang, Xiaolong Luke

    2011-12-01

    Network data often contain important attributes from various dimensions such as social affiliations and areas of expertise in a social network. If such attributes exhibit a tree structure, visualizing a compound graph consisting of tree and network structures becomes complicated. How to visually reveal patterns of a network over a tree has not been fully studied. In this paper, we propose a compound graph model, TreeNet, to support visualization and analysis of a network at multiple levels of aggregation over a tree. We also present a visualization design, TreeNetViz, to offer the multiscale and cross-scale exploration and interaction of a TreeNet graph. TreeNetViz uses a Radial, Space-Filling (RSF) visualization to represent the tree structure, a circle layout with novel optimization to show aggregated networks derived from TreeNet, and an edge bundling technique to reduce visual complexity. Our circular layout algorithm reduces both total edge-crossings and edge length and also considers hierarchical structure constraints and edge weight in a TreeNet graph. These experiments illustrate that the algorithm can reduce visual cluttering in TreeNet graphs. Our case study also shows that TreeNetViz has the potential to support the analysis of a compound graph by revealing multiscale and cross-scale network patterns. © 2011 IEEE

  6. VC-dimension of univariate decision trees.

    Science.gov (United States)

    Yildiz, Olcay Taner

    2015-02-01

    In this paper, we give and prove the lower bounds of the Vapnik-Chervonenkis (VC)-dimension of the univariate decision tree hypothesis class. The VC-dimension of the univariate decision tree depends on the VC-dimension values of its subtrees and the number of inputs. Via a search algorithm that calculates the VC-dimension of univariate decision trees exhaustively, we show that our VC-dimension bounds are tight for simple trees. To verify that the VC-dimension bounds are useful, we also use them to get VC-generalization bounds for complexity control using structural risk minimization in decision trees, i.e., pruning. Our simulation results show that structural risk minimization pruning using the VC-dimension bounds finds trees that are more accurate as those pruned using cross validation.

  7. Geodesic atlas-based labeling of anatomical trees

    DEFF Research Database (Denmark)

    Feragen, Aasa; Petersen, Jens; Owen, Megan

    2015-01-01

    We present a fast and robust atlas-based algorithm for labeling airway trees, using geodesic distances in a geometric tree-space. Possible branch label configurations for an unlabeled airway tree are evaluated using distances to a training set of labeled airway trees. In tree-space, airway tree t...... equally complete airway trees, and comparable in performance to that of experts in pulmonary medicine, emphasizing the suitability of the labeling algorithm for clinical use....

  8. On the structure of path-like trees

    OpenAIRE

    Muntaner Batle, Francesc Antoni; Rius Font, Miquel

    2007-01-01

    We study the structure of path-like trees. In order to do this, we introduce a set of trees that we call expandable trees. In this paper we also generalize the concept of path-like trees and we call such generalization generalized path-like trees. As in the case of path-like trees, generalized path-like trees, have very nice labeling properties.

  9. The spectral dimension of random trees

    International Nuclear Information System (INIS)

    Destri, Claudio; Donetti, Luca

    2002-01-01

    We present a simple yet rigorous approach to the determination of the spectral dimension of random trees, based on the study of the massless limit of the Gaussian model on such trees. As a by-product, we obtain evidence in favour of a new scaling hypothesis for the Gaussian model on generic bounded graphs and in favour of a previously conjectured exact relation between spectral and connectivity dimensions on more general tree-like structures

  10. Reconciliation with non-binary species trees.

    Science.gov (United States)

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton; Durand, Dannie

    2008-10-01

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

  11. Nonbinary tree-based phylogenetic networks

    OpenAIRE

    Jetten, Laura; van Iersel, Leo

    2016-01-01

    Rooted phylogenetic networks are used to describe evolutionary histories that contain non-treelike evolutionary events such as hybridization and horizontal gene transfer. In some cases, such histories can be described by a phylogenetic base-tree with additional linking arcs, which can for example represent gene transfer events. Such phylogenetic networks are called tree-based. Here, we consider two possible generalizations of this concept to nonbinary networks, which we call tree-based and st...

  12. Transforming phylogenetic networks: Moving beyond tree space

    OpenAIRE

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

    2016-01-01

    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 transforme...

  13. Tank waste remediation system architecture tree

    International Nuclear Information System (INIS)

    PECK, L.G.

    1999-01-01

    The TWRS Architecture Tree presented in this document is a hierarchical breakdown to support the TWRS systems engineering analysis of the TWRS physical system, including facilities, hardware and software. The purpose for this systems engineering architecture tree is to describe and communicate the system's selected and existing architecture, to provide a common structure to improve the integration of work and resulting products, and to provide a framework as a basis for TWRS Specification Tree development

  14. Tank waste remediation system architecture tree; TOPICAL

    International Nuclear Information System (INIS)

    PECK, L.G.

    1999-01-01

    The TWRS Architecture Tree presented in this document is a hierarchical breakdown to support the TWRS systems engineering analysis of the TWRS physical system, including facilities, hardware and software. The purpose for this systems engineering architecture tree is to describe and communicate the system's selected and existing architecture, to provide a common structure to improve the integration of work and resulting products, and to provide a framework as a basis for TWRS Specification Tree development

  15. Maintenance of carbohydrate transport in tall trees

    DEFF Research Database (Denmark)

    Savage, Jessica A.; Beecher, Sierra D.; Clerx, Laura

    2017-01-01

    Trees present a critical challenge to long-distance transport because as a tree grows in height and the transport pathway increases in length, the hydraulic resistance of the vascular tissue should increase. This has led many to question whether trees can rely on a passive transport mechanism to ...... that reduce transport resistance. As a result, the key to the long-standing mystery of how trees maintain phloem transport as they increase in size lies in the structure of the phloem and its ability to change hydraulic properties with plant height.......Trees present a critical challenge to long-distance transport because as a tree grows in height and the transport pathway increases in length, the hydraulic resistance of the vascular tissue should increase. This has led many to question whether trees can rely on a passive transport mechanism...... in the leaves of a tall tree in situ. Across nine deciduous species, we find that hydraulic resistance in the phloem scales inversely with plant height because of a shift in sieve element structure along the length of individual trees. This scaling relationship seems robust across multiple species despite large...

  16. Breaking the fault tree circular logic

    International Nuclear Information System (INIS)

    Lankin, M.

    2000-01-01

    Event tree - fault tree approach to model failures of nuclear plants as well as of other complex facilities is noticeably dominant now. This approach implies modeling an object in form of unidirectional logical graph - tree, i.e. graph without circular logic. However, genuine nuclear plants intrinsically demonstrate quite a few logical loops (circular logic), especially where electrical systems are involved. This paper shows the incorrectness of existing practice of circular logic breaking by elimination of part of logical dependencies and puts forward a formal algorithm, which enables the analyst to correctly model the failure of complex object, which involves logical dependencies between system and components, in form of fault tree. (author)

  17. Modular representation and analysis of fault trees

    Energy Technology Data Exchange (ETDEWEB)

    Olmos, J; Wolf, L [Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Nuclear Engineering

    1978-08-01

    An analytical method to describe fault tree diagrams in terms of their modular compositions is developed. Fault tree structures are characterized by recursively relating the top tree event to all its basic component inputs through a set of equations defining each of the modulus for the fault tree. It is shown that such a modular description is an extremely valuable tool for making a quantitative analysis of fault trees. The modularization methodology has been implemented into the PL-MOD computer code, written in PL/1 language, which is capable of modularizing fault trees containing replicated components and replicated modular gates. PL-MOD in addition can handle mutually exclusive inputs and explicit higher order symmetric (k-out-of-n) gates. The step-by-step modularization of fault trees performed by PL-MOD is demonstrated and it is shown how this procedure is only made possible through an extensive use of the list processing tools available in PL/1. A number of nuclear reactor safety system fault trees were analyzed. PL-MOD performed the modularization and evaluation of the modular occurrence probabilities and Vesely-Fussell importance measures for these systems very efficiently. In particular its execution time for the modularization of a PWR High Pressure Injection System reduced fault tree was 25 times faster than that necessary to generate its equivalent minimal cut-set description using MOCUS, a code considered to be fast by present standards.

  18. Tritium concentrations in tree ring cellulose

    International Nuclear Information System (INIS)

    Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

    1989-01-01

    Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

  19. 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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Creating ensembles of decision trees through sampling

    Science.gov (United States)

    Kamath, Chandrika; Cantu-Paz, Erick

    2005-08-30

    A system for decision tree ensembles that includes a module to read the data, a module to sort the data, a module to evaluate a potential split of the data according to some criterion using a random sample of the data, a module to split the data, and a module to combine multiple decision trees in ensembles. The decision tree method is based on statistical sampling techniques and includes the steps of reading the data; sorting the data; evaluating a potential split according to some criterion using a random sample of the data, splitting the data, and combining multiple decision trees in ensembles.

  1. 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

    2016-01-01

    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 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. PMID:26802540

  2. Big data of tree species distributions

    DEFF Research Database (Denmark)

    Serra-Diaz, Josep M.; Enquist, Brian J.; Maitner, Brian

    2018-01-01

    are currently available in big databases, several challenges hamper their use, notably geolocation problems and taxonomic uncertainty. Further, we lack a complete picture of the data coverage and quality assessment for open/public databases of tree occurrences. Methods: We combined data from five major...... and data aggregation, especially from national forest inventory programs, to improve the current publicly available data.......Background: Trees play crucial roles in the biosphere and societies worldwide, with a total of 60,065 tree species currently identified. Increasingly, a large amount of data on tree species occurrences is being generated worldwide: from inventories to pressed plants. While many of these data...

  3. TreeScaper: Visualizing and Extracting Phylogenetic Signal from Sets of Trees.

    Science.gov (United States)

    Huang, Wen; Zhou, Guifang; Marchand, Melissa; Ash, Jeremy R; Morris, David; Van Dooren, Paul; Brown, Jeremy M; Gallivan, Kyle A; Wilgenbusch, Jim C

    2016-12-01

    Modern phylogenomic analyses often result in large collections of phylogenetic trees representing uncertainty in individual gene trees, variation across genes, or both. Extracting phylogenetic signal from these tree sets can be challenging, as they are difficult to visualize, explore, and quantify. To overcome some of these challenges, we have developed TreeScaper, an application for tree set visualization as well as the identification of distinct phylogenetic signals. GUI and command-line versions of TreeScaper and a manual with tutorials can be downloaded from https://github.com/whuang08/TreeScaper/releases TreeScaper is distributed under the GNU General Public License. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Computer aided fault tree synthesis

    International Nuclear Information System (INIS)

    Poucet, A.

    1983-01-01

    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

  5. SOFT TREE: Fault Tree Technique as Applied to Software. Revision.

    Science.gov (United States)

    1983-10-01

    13 12 - 16 03 - 18 09 - 19 01 - 19 02 - 19 03 - 19 05 18. Con’t Non- Nuclear Munition, Non- Nuclear Munition Safety, Fuze Safety, Microprocessor...costucin the’ V’Y wvSoft Tree be ver fam-’il~. iar-a’--. that te persnns conihhsutnge thoftd refec be very familia wthipeetino microprocessosor atd idotwee h...ro 7- qSf" fart~b -To WA0 IFu t TOC6Lf e aF ’t9 q-EN rNz Al fC1~ATOk -1- 1AP6AG $ LA ? To.~ Yujiif’ ToA4. IWOv~:EAii CI~t~J~13Lf ToP5M A~E F CAP Avrif

  6. Encoding phylogenetic trees in terms of weighted quartets.

    Science.gov (United States)

    Grünewald, Stefan; Huber, Katharina T; Moulton, Vincent; Semple, Charles

    2008-04-01

    One of the main problems in phylogenetics is to develop systematic methods for constructing evolutionary or phylogenetic trees. For a set of species X, an edge-weighted phylogenetic X-tree or phylogenetic tree is a (graph theoretical) tree with leaf set X and no degree 2 vertices, together with a map assigning a non-negative length to each edge of the tree. Within phylogenetics, several methods have been proposed for constructing such trees that work by trying to piece together quartet trees on X, i.e. phylogenetic trees each having four leaves in X. Hence, it is of interest to characterise when a collection of quartet trees corresponds to a (unique) phylogenetic tree. Recently, Dress and Erdös provided such a characterisation for binary phylogenetic trees, that is, phylogenetic trees all of whose internal vertices have degree 3. Here we provide a new characterisation for arbitrary phylogenetic trees.

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

    NARCIS (Netherlands)

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

    2011-01-01

    1. Tree architecture is thought to allow species to partition horizontal and vertical light gradients in the forest canopy. Tree architecture is closely related to light capture, carbon gain and the efficiency with which trees reach the canopy. Previous studies that investigated how light gradients

  8. Minimum variance rooting of phylogenetic trees and implications for species tree reconstruction.

    Science.gov (United States)

    Mai, Uyen; Sayyari, Erfan; Mirarab, Siavash

    2017-01-01

    Phylogenetic trees inferred using commonly-used models of sequence evolution are unrooted, but the root position matters both for interpretation and downstream applications. This issue has been long recognized; however, whether the potential for discordance between the species tree and gene trees impacts methods of rooting a phylogenetic tree has not been extensively studied. In this paper, we introduce a new method of rooting a tree based on its branch length distribution; our method, which minimizes the variance of root to tip distances, is inspired by the traditional midpoint rerooting and is justified when deviations from the strict molecular clock are random. Like midpoint rerooting, the method can be implemented in a linear time algorithm. In extensive simulations that consider discordance between gene trees and the species tree, we show that the new method is more accurate than midpoint rerooting, but its relative accuracy compared to using outgroups to root gene trees depends on the size of the dataset and levels of deviations from the strict clock. We show high levels of error for all methods of rooting estimated gene trees due to factors that include effects of gene tree discordance, deviations from the clock, and gene tree estimation error. Our simulations, however, did not reveal significant differences between two equivalent methods for species tree estimation that use rooted and unrooted input, namely, STAR and NJst. Nevertheless, our results point to limitations of existing scalable rooting methods.

  9. Forest FIRE and FIRE wood : tools for tree automata and tree algorithms

    NARCIS (Netherlands)

    Cleophas, L.G.W.A.; Piskorski, J.; Watson, B.W.; Yli-Jyrä, A.

    2009-01-01

    Pattern matching, acceptance, and parsing algorithms on node-labeled, ordered, ranked trees ('tree algorithms') are important for applications such as instruction selection and tree transformation/term rewriting. Many such algorithms have been developed. They often are based on results from such

  10. 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 or...

  11. How many trees are enough? Tree death and the urban canopy

    Science.gov (United States)

    Lara A. Roman

    2014-01-01

    Massive city tree planting campaigns have invigorated the urban forestry movement, and engaged politicians, planners, and the public in urban greening. Million tree initiatives have been launched in Los Angeles, CA; Denver, CO; New York City, NY; Philadelphia, PA, and other cities. Sacramento, CA even has a five million tree program. These...

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

    Science.gov (United States)

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

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

  13. 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

  14. 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.

  15. Injective Labeled Oriented Trees are Aspherical

    OpenAIRE

    Harlander, Jens; Rosebrock, Stephan

    2012-01-01

    A labeled oriented tree is called injective if each generator occurs at most once as an edge label. We show that injective labeled oriented trees are aspherical. The proof relies on a new relative asphericity test based on a lemma of Stallings.

  16. Tree root mapping with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available In this paper, the application of ground penetrating radar (GPR) for the mapping of near surface tree roots is demonstrated. GPR enables tree roots to be mapped in a non-destructive and cost-effective manner and is therefore a useful prospecting...

  17. Portraits of Non-Tree Families

    NARCIS (Netherlands)

    Balgooy, van M.M.J.

    2001-01-01

    This is the third and final volume of the series ‘Malesian Seed Plants’. It contains the ‘portraits’ of 124 non-tree families, i.e. families which are mainly herbaceous, climbing, shrubby, or trees with a stem diameter at breast height of less than 10 cm or a height of less than 10 m. Users of the

  18. Smoothed analysis of binary search trees

    NARCIS (Netherlands)

    Manthey, Bodo; Reischuk, Rüdiger

    2007-01-01

    Binary search trees are one of the most fundamental data structures. While the height of such a tree may be linear in the worst case, the average height with respect to the uniform distribution is only logarithmic. The exact value is one of the best studied problems in average-case complexity. We

  19. Tools for valuing tree and park services

    Science.gov (United States)

    E.G. McPherson

    2010-01-01

    Arborists and urban foresters plan, design, construct, and manage trees and parks in cities throughout the world. These civic improvements create walkable, cool environments, save energy, reduce stormwater runoff, sequester carbon dioxide, and absorb air pollutants. The presence of trees and green spaces in cities is associated with increases in property values,...

  20. A coinductive calculus of binary trees

    NARCIS (Netherlands)

    A.M. Silva (Alexandra); J.J.M.M. Rutten (Jan)

    2007-01-01

    htmlabstractWe study the set T_A of infinite binary trees with nodes labelled in a semiring A from a coalgebraic perspective. We present coinductive definition and proof principles based on the fact that T_A carries a final coalgebra structure. By viewing trees as formal power series, we develop a

  1. Structure of an urban Christmas tree market

    Science.gov (United States)

    Thomas H. Pendleton; Lawrence D. Garrett; Lawrence D. Garrett

    1973-01-01

    The retail Christmas tree market in Winston-Salem, N.C., was studied 3 years. Types of retailers and their sales are described. Best sales were made by dealers who had lots on heavily traveled streets in business districts, had ample parking facilities, advertised, and displayed their trees well.

  2. The production of homozygous tree material

    Science.gov (United States)

    Reinhard F. Stettler; George E. Howe

    1966-01-01

    Homozygous trees will never be the desired ultimate step in a forest tree improvement program. However, they will serve many purposes in forest genetics research: (1) in the detection of genetic markers; (2) in the isolation of traits under simple genetic control for the study of growth and differentiation phenomena; (3) as a tool as well as reference material in the...

  3. Improved Anonymity for Key-trees

    NARCIS (Netherlands)

    Veugen, P.J.M.; Beye, M.

    2013-01-01

    Randomized hash-lock protocols for Radio Frequency IDentification (RFID) tags offer forward untraceability, but incur heavy search on the server. Key trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags.

  4. Sprouting of dormant buds on border trees

    Science.gov (United States)

    G.R., Jr. Trimble; H. Clay Smith; H. Clay Smith

    1970-01-01

    As part of an evaluation of silvicultura1 systems used in managing Appalachian hardwoods, we are studying degrade of border trees surrounding harvest-cut openings made in the patch cutting and group selection systems. One facet of this research dealt with determining what portion of visually evident dormant buds on border tree boles sprouted when the openings were cut...

  5. Exploring connections between trees and human health

    Science.gov (United States)

    Geoffrey Donovan; Marie. Oliver

    2014-01-01

    Humans have intuitively understood the value of trees to their physical and mental health since the beginning of recorded time. A scientist with the Pacific Northwest Research Station wondered if such a link could be scientifically validated. His research team took advantage of an infestation of emerald ash borer, an invasive pest that kills ash trees, to conduct a...

  6. Environmental stress and whole-tree physiology

    Science.gov (United States)

    Peter L. Jr. Lorio

    1993-01-01

    Interactions among bark beetles, pathogens, and conifers constitute a triangle. Another triangle of interactions exist among the invading organism (bark beetles and pathogens), the trees, and the environment. How important, variable or constant, simple or complex, is the role of trees in these triangles? Understanding the wide range of interactions that take place...

  7. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2015-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  8. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2012-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  9. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2015-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant§ refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  10. Pulp quality from small-diameter trees.

    Science.gov (United States)

    G.C. Myers; S. Kumar; R.R. Gustafson; R.J. Barbour; S.M. Abubakr

    1997-01-01

    Kraft and thermomechanical (TMP) pulps were prepared and evaluated from lodgepole pine and mixed Douglas-fir/western larch sawmill residue chips; lodgepole pine, Douglas-fir, and western larch submerchantable logs; and lodgepole pine, Douglas-fir, and western larch small trees and tops. Kraft pulp from small trees and tops was identical to that from submerchantable...

  11. FAT-miner: mining frequent attribute trees

    NARCIS (Netherlands)

    Knijf, de J.; Cho, Y.; Wainwright, R.L.; Haddad, H.; Shin, S.Y.; Koo, Y.W.

    2007-01-01

    Data that can conceptually be viewed as tree structures abounds in domains such as bio-informatics, web logs, XML databases and multi-relational databases. Besides structural information such as nodes and edges, tree structured data also often contains attributes, that represent properties of nodes.

  12. The "Ride for Russia" Tree Lichen Survey

    Science.gov (United States)

    Young, Simon

    2013-01-01

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

  13. Naive Fault Tree : formulation of the approach

    NARCIS (Netherlands)

    Rajabalinejad, M

    2017-01-01

    Naive Fault Tree (NFT) accepts a single value or a range of values for each basic event and returns values for the top event. This accommodates the need of commonly used Fault Trees (FT) for precise data making them prone to data concerns and limiting their area of application. This paper extends

  14. Market-based approaches to tree valuation

    Science.gov (United States)

    Geoffrey H. Donovan; David T. Butry

    2008-01-01

    A recent four-part series in Arborist News outlined different appraisal processes used to value urban trees. The final article in the series described the three generally accepted approaches to tree valuation: the sales comparison approach, the cost approach, and the income capitalization approach. The author, D. Logan Nelson, noted that the sales comparison approach...

  15. Grading sugar pine saw logs in trees.

    Science.gov (United States)

    John W. Henley

    1972-01-01

    Small limbs and small overgrown limbs cause problems when grading saw logs in sugar pine trees. Surface characteristics and lumber recovery information for 426 logs from 64 sugar pine trees were examined. Resulting modifications in the grading specification that allow a grader to ignore small limbs and small limb indicators do not appear to decrease the performance of...

  16. How early ferns became trees.

    Science.gov (United States)

    Galtier, J; Hueber, F M

    2001-09-22

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

  17. Genealogical Trees of Scientific Papers.

    Science.gov (United States)

    Waumans, Michaël Charles; Bersini, Hugues

    2016-01-01

    Many results have been obtained when studying scientific papers citations databases in a network perspective. Articles can be ranked according to their current in-degree and their future popularity or citation counts can even be predicted. The dynamical properties of such networks and the observation of the time evolution of their nodes started more recently. This work adopts an evolutionary perspective and proposes an original algorithm for the construction of genealogical trees of scientific papers on the basis of their citation count evolution in time. The fitness of a paper now amounts to its in-degree growing trend and a "dying" paper will suddenly see this trend declining in time. It will give birth and be taken over by some of its most prevalent citing "offspring". Practically, this might be used to trace the successive published milestones of a research field.

  18. Structure theorems for game trees.

    Science.gov (United States)

    Govindan, Srihari; Wilson, Robert

    2002-06-25

    Kohlberg and Mertens [Kohlberg, E. & Mertens, J. (1986) Econometrica 54, 1003-1039] proved that the graph of the Nash equilibrium correspondence is homeomorphic to its domain when the domain is the space of payoffs in normal-form games. A counterexample disproves the analog for the equilibrium outcome correspondence over the space of payoffs in extensive-form games, but we prove an analog when the space of behavior strategies is perturbed so that every path in the game tree has nonzero probability. Without such perturbations, the graph is the closure of the union of a finite collection of its subsets, each diffeomorphic to a corresponding path-connected open subset of the space of payoffs. As an application, we construct an algorithm for computing equilibria of an extensive-form game with a perturbed strategy space, and thus approximate equilibria of the unperturbed game.

  19. Tree and nontree multiparticle amplitudes

    International Nuclear Information System (INIS)

    Goldberg, H.; Vaughn, M.T.

    1991-01-01

    We examine the behavior of the connected n-point function in a zero-dimensional scalar theory (scrL=-1/2m 2 φ 2 -1/4λφ 4 ). The problematic n exclamation point(√λ ) n behavior for large n, previously found for tree graphs in scalar field theory, is again obtained in saddle-point approximation in this model. However, a similar behavior, n exclamation point[f(λ)] n , persists in the full theory, where f∼ √λ for λ→0, f∼λ -1/4 for λ much-gt 1. This behavior can be traced to the existence of zeros in the complex J plane of the generating functional Z(J), which in turn is controlled by the asymptotic behavior in |J| of Z(J) calculated in saddle-point approximation. The application of these results to field theory is discussed

  20. Stand conditions and tree characteristics affect quality of longleaf pine for red-cockaded woodpecker cavity trees

    Science.gov (United States)

    W.G. Ross; D.L. Kulhavy; R.N. Conner

    1997-01-01

    We measured resin flow of longleaf (Pinus palustris Mill.) pines in red-cockaded woodpecker (Picoides borealis Vieillot) clusters in the Angelina National Forest in Texas, and the Apalachicola National Forest in Florida. Sample trees were categorized as active cavity trees, inactive cavity trees and control trees. Sample trees were further...

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

    OpenAIRE

    N. Price, Morgan

    2009-01-01

    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 i...

  2. Language distance and tree reconstruction

    International Nuclear Information System (INIS)

    Petroni, Filippo; Serva, Maurizio

    2008-01-01

    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

  3. 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.

  4. 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.

  5. Molecular basis of angiosperm tree architecture.

    Science.gov (United States)

    Hollender, Courtney A; Dardick, Chris

    2015-04-01

    The architecture of trees greatly impacts the productivity of orchards and forestry plantations. Amassing greater knowledge on the molecular genetics that underlie tree form can benefit these industries, as well as contribute to basic knowledge of plant developmental biology. This review describes the fundamental components of branch architecture, a prominent aspect of tree structure, as well as genetic and hormonal influences inferred from studies in model plant systems and from trees with non-standard architectures. The bulk of the molecular and genetic data described here is from studies of fruit trees and poplar, as these species have been the primary subjects of investigation in this field of science. No claim to original US Government works. New Phytologist © 2014 New Phytologist Trust.

  6. Tree growth studies on uranium mill tailings

    International Nuclear Information System (INIS)

    Murray, D.R.; Turcotte, M.

    1982-01-01

    Coniferous trees planted in 1974 and deciduous species that have volunteered since 1970 on uranium mill tailings that had been stabilized to varying degrees using limestone and vegetation were evaluated. Their survival and growth rates were compared with those from other investigations. Competition for light appears to be a major contributor to mortality. Differences in soil moisture conditions under a tree stand as compared to those under a grass sward are potentially significant enough to affect the tailings hydrology and effluent contamination. Recommendations include planting seeds of deciduous species or deciduous and coniferous seedlings on strips of freshly disturbed tailings. The disturbed strips would provide reduced competition for the initial year and assist in tree survival. The planting of block stands of coniferous or deciduous trees would be useful for evaluating the hydrological impact of the trees as compared to the present grass sward

  7. 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.

  8. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sören

    2017-11-22

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

  9. Phylogenetic search through partial tree mixing

    Science.gov (United States)

    2012-01-01

    Background Recent advances in sequencing technology have created large data sets upon which phylogenetic inference can be performed. Current research is limited by the prohibitive time necessary to perform tree search on a reasonable number of individuals. This research develops new phylogenetic algorithms that can operate on tens of thousands of species in a reasonable amount of time through several innovative search techniques. Results When compared to popular phylogenetic search algorithms, better trees are found much more quickly for large data sets. These algorithms are incorporated in the PSODA application available at http://dna.cs.byu.edu/psoda Conclusions The use of Partial Tree Mixing in a partition based tree space allows the algorithm to quickly converge on near optimal tree regions. These regions can then be searched in a methodical way to determine the overall optimal phylogenetic solution. PMID:23320449

  10. Success tree method of resources evaluation

    International Nuclear Information System (INIS)

    Chen Qinglan; Sun Wenpeng

    1994-01-01

    By applying the reliability theory in system engineering, the success tree method is used to transfer the expert's recognition on metallogenetic regularities into the form of the success tree. The aim of resources evaluation is achieved by means of calculating the metallogenetic probability or favorability of the top event of the success tree. This article introduces in detail, the source, principle of the success tree method and three kinds of calculation methods, expounds concretely how to establish the success tree of comprehensive uranium metallogenesis as well as the procedure from which the resources evaluation is performed. Because this method has not restrictions on the number of known deposits and calculated area, it is applicable to resources evaluation for different mineral species, types and scales and possesses good prospects of development

  11. Radioecological investigations on tree rings of spruce

    International Nuclear Information System (INIS)

    Haas, G.; Mueller, A.

    1995-01-01

    Tree ring analysis contributes essentially to the explanation of physiological and element-specific transport phenomena in trees. After the accident in Chernobyl the behaviour of Cs-134 and Cs-137 in trees is most informative for the prediction of the future development of the distribution of these elements. In this study the uptake and the long term behaviour of Cs-134, Cs-137, Pb-210, Ra-226, Ra-228, K-40, Th-228, Th-230, Th-232, U-234 and U-238 in tree rings of spruce are examined by α- and γ-spectrometry. All samples are dried at 105C and ashed at 450C in a muffle furnace. The distributions found in the tree rings vary for different radionuclides. A soil profile from the spruce stand provides additional information

  12. Seeing the forest for the trees

    DEFF Research Database (Denmark)

    Ribbons, Relena Rose

    Tree species influence soils above and belowground communities through leaf litter and root inputs. Soil microbial communities can directly influence tree growth and development through processes such as decomposition of leaves, and indirectly through chemical transformation of nutrients in soils...... as an influence of altered C:N ratios due to leaf litter inputs. This thesis aims to document some of the mechanisms by which trees influence soil microbial communities and nitrogen cycling processes like gross and net ammonification and nitrification. This thesis also aims to determine the role of site nitrogen...... status on modulating those tree species effects. The effects of tree species on ammonification and nitrification rates in forest floors and mineral soils were explored, and related to functional genetic markers for ammonia-oxidation by archaea and bacteria (amoA AOA and AOB), bacterial denitrification...

  13. Track treeing mechanism and its application

    International Nuclear Information System (INIS)

    Li Boyang

    1993-01-01

    Based on electrostriction and fracture mechanics, experiment observation and data-processing, two models (restriction among tree tracks and induction of tree track onto stress concentrated spots) and factors (restriction and induction) are proposed; The existence of four types of plastic zone (spot-block pz, single crack isolate pz, transition from isolate to block pz and crack-block pz) and two types of annex (plastic zone and crack zone) are pointed out. The development regularities of Gp (diameter of plastic zone), G(diameter of tree track), S(tree track density) and total areal of tree track (SG 2 ) in two basic experiments (H=H+dH, H=Hc H-field strength) are described by using four basic formulae. (author)

  14. Tree agency and urban forest governance

    DEFF Research Database (Denmark)

    Konijnendijk, Cecil Cornelis

    2016-01-01

    governance also involving businesses and civic society. However, governance theory usually does not consider the role of non-human agency, which can be considered problematic due to, for example, the important role of urban trees in place making. The purpose of this paper is to provide further insight...... into the importance of considering tree agency in governance. Design/methodology/approach – Taking an environmental governance and actor network theory perspective, the paper presents a critical view of current urban forest governance, extending the perspective to include not only a wide range of human actors......, but also trees as important non-human actors. Findings – Urban forest governance has become more complex and involves a greater range of actors and actor networks. However, the agency of trees in urban forest governance is seldom well developed. Trees, in close association with local residents, create...

  15. Design of data structures for mergeable trees

    DEFF Research Database (Denmark)

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

    2006-01-01

    merge operation can change many arcs. In spite of this, we develop a data structure that supports merges and all other standard tree operations in O(log2 n) amortized time on an n-node forest. For the special case that occurs in the motivating application, in which arbitrary arc deletions...... are not allowed, we give a data structure with an O(log n) amortized time bound per operation, which is asymptotically optimal. The analysis of both algorithms is not straightforward and requires ideas not previously used in the study of dynamic trees. We explore the design space of algorithms for the problem......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 single...

  16. Barking up the wrong tree: injuries due to falls from trees in Solomon Islands.

    Science.gov (United States)

    Negin, Joel; Vizintin, Pavle; Houasia, Patrick; Martiniuk, Alexandra L C

    2014-12-11

    To investigate tree-related injuries in Solomon Islands by the types of trees involved, who is affected and the types of injuries caused. Descriptive case series of all cases of injuries related to trees presenting to the National Referral Hospital in Honiara from 1994 to 2011. Data were collected by the attending clinician using a Trauma Epidemiology form, which provides information on age, sex, cause of injury and type of fracture. Number of injuries by tree type, sex and age. Of the 7651 injuries in the database, 1107 (14%) were caused by falls from trees. Falls from coconut trees led to the highest number of injuries, followed by falls from mango, guava, apple and nut trees. Overall, 85% of injuries occurred in individuals aged trees, 77% of patients were aged tree types. Overall, 71% of injuries occurred among males. Of all injuries, 92% were fractures, 3% were dislocations and 5% were non-fracture, non-dislocation injuries. The arm (including wrist, elbow and hand) was the most common location of injury across all tree types. Distal radius fractures in the forearm were particularly common, as were ulna fractures. While mangos and guavas are undeniably delicious, the quest for their flesh can be hazardous. Children will always climb trees, but the search for food among children in lower-income settings may lead to higher rates of injury.

  17. New perspectives on the ecology of tree structure and tree communities through terrestrial laser scanning.

    Science.gov (United States)

    Malhi, Yadvinder; Jackson, Tobias; Patrick Bentley, Lisa; Lau, Alvaro; Shenkin, Alexander; Herold, Martin; Calders, Kim; Bartholomeus, Harm; Disney, Mathias I

    2018-04-06

    Terrestrial laser scanning (TLS) opens up the possibility of describing the three-dimensional structures of trees in natural environments with unprecedented detail and accuracy. It is already being extensively applied to describe how ecosystem biomass and structure vary between sites, but can also facilitate major advances in developing and testing mechanistic theories of tree form and forest structure, thereby enabling us to understand why trees and forests have the biomass and three-dimensional structure they do. Here we focus on the ecological challenges and benefits of understanding tree form, and highlight some advances related to capturing and describing tree shape that are becoming possible with the advent of TLS. We present examples of ongoing work that applies, or could potentially apply, new TLS measurements to better understand the constraints on optimization of tree form. Theories of resource distribution networks, such as metabolic scaling theory, can be tested and further refined. TLS can also provide new approaches to the scaling of woody surface area and crown area, and thereby better quantify the metabolism of trees. Finally, we demonstrate how we can develop a more mechanistic understanding of the effects of avoidance of wind risk on tree form and maximum size. Over the next few years, TLS promises to deliver both major empirical and conceptual advances in the quantitative understanding of trees and tree-dominated ecosystems, leading to advances in understanding the ecology of why trees and ecosystems look and grow the way they do.

  18. Interactive Tree Of Life v2: online annotation and display of phylogenetic trees made easy.

    Science.gov (United States)

    Letunic, Ivica; Bork, Peer

    2011-07-01

    Interactive Tree Of Life (http://itol.embl.de) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. It is freely available and open to everyone. In addition to classical tree viewer functions, iTOL offers many novel ways of annotating trees with various additional data. Current version introduces numerous new features and greatly expands the number of supported data set types. Trees can be interactively manipulated and edited. A free personal account system is available, providing management and sharing of trees in user defined workspaces and projects. Export to various bitmap and vector graphics formats is supported. Batch access interface is available for programmatic access or inclusion of interactive trees into other web services.

  19. 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....

  20. An efficient and extensible approach for compressing phylogenetic trees

    KAUST Repository

    Matthews, Suzanne J; Williams, Tiffani L

    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

  1. Development of tree hollows in pedunculate oak (Quercus robur)

    OpenAIRE

    Ranius, Thomas; Niklasson, Mats; Berg, Niclas

    2009-01-01

    Many invertebrates, birds and mammals are dependent on hollow trees. For landscape planning that aims at persistence of species inhabiting hollow trees it is crucial to understand the development of such trees. In this study we constructed an individual-based simulation model to predict diameter distribution and formation of hollows in oak tree populations. Based on tree-ring data from individual trees, we estimated the ages when hollow formation commences for pedunculate oak (Quercus robur) ...

  2. 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...

  3. 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.

  4. An efficient and extensible approach for compressing phylogenetic trees.

    Science.gov (United States)

    Matthews, Suzanne J; Williams, Tiffani L

    2011-10-18

    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. 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. 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.

  5. Users' manual for the FTDRAW (Fault Tree Draw) code

    International Nuclear Information System (INIS)

    Oikawa, Tetsukuni; Hikawa, Michihiro; Tanabe, Syuichi; Nakamura, Norihiro

    1985-02-01

    This report provides the information needed to use the FTDRAW (Fault Tree Draw) code, which is designed for drawing a fault tree. The FTDRAW code has several optional functions, such as the overview of a fault tree output, fault tree output in English description, fault tree output in Japanese description and summary tree output. Inputs for the FTDRAW code are component failure rate information and gate information which are filed out by a execution of the FTA-J (Fault Tree Analysis-JAERI) code system and option control data. Using the FTDRAW code, we can get drawings of fault trees which is easy to see, efficiently. (author)

  6. Cafts: computer aided fault tree analysis

    International Nuclear Information System (INIS)

    Poucet, A.

    1985-01-01

    The fault tree technique has become a standard tool for the analysis of safety and reliability of complex system. In spite of the costs, which may be high for a complete and detailed analysis of a complex plant, the fault tree technique is popular and its benefits are fully recognized. Due to this applications of these codes have mostly been restricted to simple academic examples and rarely concern complex, real world systems. In this paper an interactive approach to fault tree construction is presented. The aim is not to replace the analyst, but to offer him an intelligent tool which can assist him in modeling complex systems. Using the CAFTS-method, the analyst interactively constructs a fault tree in two phases: (1) In a first phase he generates an overall failure logic structure of the system; the macrofault tree. In this phase, CAFTS features an expert system approach to assist the analyst. It makes use of a knowledge base containing generic rules on the behavior of subsystems and components; (2) In a second phase the macrofault tree is further refined and transformed in a fully detailed and quantified fault tree. In this phase a library of plant-specific component failure models is used

  7. Decision Tree Technique for Particle Identification

    International Nuclear Information System (INIS)

    Quiller, Ryan

    2003-01-01

    Particle identification based on measurements such as the Cerenkov angle, momentum, and the rate of energy loss per unit distance (-dE/dx) is fundamental to the BaBar detector for particle physics experiments. It is particularly important to separate the charged forms of kaons and pions. Currently, the Neural Net, an algorithm based on mapping input variables to an output variable using hidden variables as intermediaries, is one of the primary tools used for identification. In this study, a decision tree classification technique implemented in the computer program, CART, was investigated and compared to the Neural Net over the range of momenta, 0.25 GeV/c to 5.0 GeV/c. For a given subinterval of momentum, three decision trees were made using different sets of input variables. The sensitivity and specificity were calculated for varying kaon acceptance thresholds. This data was used to plot Receiver Operating Characteristic curves (ROC curves) to compare the performance of the classification methods. Also, input variables used in constructing the decision trees were analyzed. It was found that the Neural Net was a significant contributor to decision trees using dE/dx and the Cerenkov angle as inputs. Furthermore, the Neural Net had poorer performance than the decision tree technique, but tended to improve decision tree performance when used as an input variable. These results suggest that the decision tree technique using Neural Net input may possibly increase accuracy of particle identification in BaBar

  8. 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.

  9. 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.

  10. Nodal distances for rooted phylogenetic trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2010-08-01

    Dissimilarity measures for (possibly weighted) phylogenetic trees based on the comparison of their vectors of path lengths between pairs of taxa, have been present in the systematics literature since the early seventies. For rooted phylogenetic trees, however, these vectors can only separate non-weighted binary trees, and therefore these dissimilarity measures are metrics only on this class of rooted phylogenetic trees. In this paper we overcome this problem, by splitting in a suitable way each path length between two taxa into two lengths. We prove that the resulting splitted path lengths matrices single out arbitrary rooted phylogenetic trees with nested taxa and arcs weighted in the set of positive real numbers. This allows the definition of metrics on this general class of rooted phylogenetic trees by comparing these matrices through metrics in spaces M(n)(R) of real-valued n x n matrices. We conclude this paper by establishing some basic facts about the metrics for non-weighted phylogenetic trees defined in this way using L(p) metrics on M(n)(R), with p [epsilon] R(>0).

  11. Topological and categorical properties of binary trees

    Directory of Open Access Journals (Sweden)

    H. Pajoohesh

    2008-04-01

    Full Text Available Binary trees are very useful tools in computer science for estimating the running time of so-called comparison based algorithms, algorithms in which every action is ultimately based on a prior comparison between two elements. For two given algorithms A and B where the decision tree of A is more balanced than that of B, it is known that the average and worst case times of A will be better than those of B, i.e., ₸A(n ≤₸B(n and TWA (n≤TWB (n. Thus the most balanced and the most imbalanced binary trees play a main role. Here we consider them as semilattices and characterize the most balanced and the most imbalanced binary trees by topological and categorical properties. Also we define the composition of binary trees as a commutative binary operation, *, such that for binary trees A and B, A * B is the binary tree obtained by attaching a copy of B to any leaf of A. We show that (T,* is a commutative po-monoid and investigate its properties.

  12. 14C concentrations in tree stems, 1

    International Nuclear Information System (INIS)

    Kikata, Yoji; Yonenobu, Hitoshi; Morishita, Fumio; Hattori, Yoshiaki; Marsoen, S.N.

    1993-01-01

    The 14 C concentrations in trees sampled at various latitudes were measured with a Tandetron Accelerator Mass Spectrometer at Nagoya University. The growing periods of the parts for 14 C measurements were estimated by the relationship between meteorological conditions and the appearance of anatomical features of annual rings such as false rings, latewood formation, and so on. The following results were obtained: 1. The latitude dependence of the 14 C variation is found in tree stems as well as in the atmosphere. 2. The 14 C concentrations in tree stems are almost equal to those in the atmosphere at the latitude where the tree had grown and at the time when the sampled section is formed. Therefore the 14 C concentrations in the atmosphere are estimated by those of the tree stems. 3. The time when the 14 C concentration in the tree showed its maximum value has difference of 1 - 2 years with that of the latitude where the tree had grown. 4. This phenomena seemed to be related closely with the mechanism of global mixing of 14 CO 2 produced by atmospheric nuclear weapon tests. This mechanism causes a time lag of 14 C variation between northern and southern hemisphere. (author)

  13. Human reliability analysis using event trees

    International Nuclear Information System (INIS)

    Heslinga, G.

    1983-01-01

    The shut-down procedure of a technologically complex installation as a nuclear power plant consists of a lot of human actions, some of which have to be performed several times. The procedure is regarded as a chain of modules of specific actions, some of which are analyzed separately. The analysis is carried out by making a Human Reliability Analysis event tree (HRA event tree) of each action, breaking down each action into small elementary steps. The application of event trees in human reliability analysis implies more difficulties than in the case of technical systems where event trees were mainly used until now. The most important reason is that the operator is able to recover a wrong performance; memory influences play a significant role. In this study these difficulties are dealt with theoretically. The following conclusions can be drawn: (1) in principle event trees may be used in human reliability analysis; (2) although in practice the operator will recover his fault partly, theoretically this can be described as starting the whole event tree again; (3) compact formulas have been derived, by which the probability of reaching a specific failure consequence on passing through the HRA event tree after several times of recovery is to be calculated. (orig.)

  14. Benefits of tree mixes in carbon plantings

    Science.gov (United States)

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

    2013-10-01

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

  15. Atmospheric carbon reduction by urban trees

    International Nuclear Information System (INIS)

    Nowak, D.J.

    1993-01-01

    Trees, because they sequester atmospheric carbon through their growth process and conserve energy in urban areas, have been suggested as one means to combat increasing levels of atmospheric carbon. Analysis of the urban forest in Oakland, California (21% tree cover), reveals a tree carbon storage level of 11·0 metric tons/hectare. Trees in the area of the 1991 fire in Oakland stored approximately 14,500 metric tons of carbon, 10% of the total amount stored by Oakland's urban forest. National urban forest carbon storage in the United States (28% tree cover) is estimated at between 350 and 750 million metric tons. Establishment of 10 million urban trees annually over the next 10 years is estimated to sequester and offset the production of 363 million metric tons of carbon over the next 50 years-less than 1% of the estimated carbon emissions in the United States over the same time period. Advantages and limitations of managing urban trees to reduce atmospheric carbon are discussed. 36 refs., 2 figs., 3 tabs

  16. 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. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Comprehensive decision tree models in bioinformatics.

    Directory of Open Access Journals (Sweden)

    Gregor Stiglic

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

  18. Comprehensive decision tree models in bioinformatics.

    Science.gov (United States)

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

    2012-01-01

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

  19. IcyTree: rapid browser-based visualization for phylogenetic trees and networks.

    Science.gov (United States)

    Vaughan, Timothy G

    2017-08-01

    IcyTree is an easy-to-use application which can be used to visualize a wide variety of phylogenetic trees and networks. While numerous phylogenetic tree viewers exist already, IcyTree distinguishes itself by being a purely online tool, having a responsive user interface, supporting phylogenetic networks (ancestral recombination graphs in particular), and efficiently drawing trees that include information such as ancestral locations or trait values. IcyTree also provides intuitive panning and zooming utilities that make exploring large phylogenetic trees of many thousands of taxa feasible. IcyTree is a web application and can be accessed directly at http://tgvaughan.github.com/icytree . Currently supported web browsers include Mozilla Firefox and Google Chrome. IcyTree is written entirely in client-side JavaScript (no plugin required) and, once loaded, does not require network access to run. IcyTree is free software, and the source code is made available at http://github.com/tgvaughan/icytree under version 3 of the GNU General Public License. tgvaughan@gmail.com. © The Author(s) 2017. Published by Oxford University Press.

  20. 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.

  1. Using fuzzy arithmetic in containment event trees

    International Nuclear Information System (INIS)

    Rivera, S.S.; Baron, Jorge H.

    2000-01-01

    The use of fuzzy arithmetic is proposed for the evaluation of containment event trees. Concepts such as improbable, very improbable, and so on, which are subjective by nature, are represented by fuzzy numbers. The quantitative evaluation of containment event trees is based on the extension principle, by which operations on real numbers are extended to operations on fuzzy numbers. Expert knowledge is considered as state of the base variable with a normal distribution, which is considered to represent the membership function. Finally, this paper presents results of an example calculation of a containment event tree for the CAREM-25 nuclear power plant, presently under detailed design stage at Argentina. (author)

  2. 137Cs distribution in guava trees

    International Nuclear Information System (INIS)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M.

    2004-01-01

    This paper presents results of 137 Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the 137 Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of 137 Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  3. {sup 137}Cs distribution in guava trees

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica

    2004-09-15

    This paper presents results of {sup 137}Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the {sup 137}Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of {sup 137}Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  4. Fault tree analysis for vital area identification

    International Nuclear Information System (INIS)

    Varnado, G.B.; Ortiz, N.R.

    1978-01-01

    This paper discusses the use of fault tree analysis to identify those areas of nuclear fuel cycle facilities which must be protected to prevent acts of sabotage that could lead to sifnificant release of radioactive material. By proper manipulation of the fault trees for a plant, an analyst can identify vital areas in a manner consistent with regulatory definitions. This paper discusses the general procedures used in the analysis of any nuclear facility. In addition, a structured, generic approach to the development of the fault trees for nuclear power reactors is presented along with selected results of the application of the generic approach to several plants

  5. Random tree growth by vertex splitting

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  6. The decision tree approach to classification

    Science.gov (United States)

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

    1975-01-01

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

  7. IND - THE IND DECISION TREE PACKAGE

    Science.gov (United States)

    Buntine, W.

    1994-01-01

    A common approach to supervised classification and prediction in artificial intelligence and statistical pattern recognition is the use of decision trees. A tree is "grown" from data using a recursive partitioning algorithm to create a tree which has good prediction of classes on new data. Standard algorithms are CART (by Breiman Friedman, Olshen and Stone) and ID3 and its successor C4 (by Quinlan). As well as reimplementing parts of these algorithms and offering experimental control suites, IND also introduces Bayesian and MML methods and more sophisticated search in growing trees. These produce more accurate class probability estimates that are important in applications like diagnosis. IND is applicable to most data sets consisting of independent instances, each described by a fixed length vector of attribute values. An attribute value may be a number, one of a set of attribute specific symbols, or it may be omitted. One of the attributes is delegated the "target" and IND grows trees to predict the target. Prediction can then be done on new data or the decision tree printed out for inspection. IND provides a range of features and styles with convenience for the casual user as well as fine-tuning for the advanced user or those interested in research. IND can be operated in a CART-like mode (but without regression trees, surrogate splits or multivariate splits), and in a mode like the early version of C4. Advanced features allow more extensive search, interactive control and display of tree growing, and Bayesian and MML algorithms for tree pruning and smoothing. These often produce more accurate class probability estimates at the leaves. IND also comes with a comprehensive experimental control suite. IND consists of four basic kinds of routines: data manipulation routines, tree generation routines, tree testing routines, and tree display routines. The data manipulation routines are used to partition a single large data set into smaller training and test sets. The

  8. Least Squares Methods for Equidistant Tree Reconstruction

    OpenAIRE

    Fahey, Conor; Hosten, Serkan; Krieger, Nathan; Timpe, Leslie

    2008-01-01

    UPGMA is a heuristic method identifying the least squares equidistant phylogenetic tree given empirical distance data among $n$ taxa. We study this classic algorithm using the geometry of the space of all equidistant trees with $n$ leaves, also known as the Bergman complex of the graphical matroid for the complete graph $K_n$. We show that UPGMA performs an orthogonal projection of the data onto a maximal cell of the Bergman complex. We also show that the equidistant tree with the least (Eucl...

  9. A review of pruning fruit trees

    Science.gov (United States)

    Zhang, L.; Koc, A. B.; Wang, X. N.; Jiang, Y. X.

    2018-05-01

    The focus of this review is to present the results of studies and articles about ways to prune fruit trees. Pruning should be done in late winter or early spring so that the infection risk can be significantly decreased. This review will also offer an overview of methods to prevent infections and speed up recovery on the trees. The following is an interpretation of why high-power ultrasonic assisted pruning in the fruits trees is needed and will elaborate on the efficiency, labor costs, and safety, as well as space, location, and some environmental issues.

  10. 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.

  11. Diagnostic of dry rot in living trees

    International Nuclear Information System (INIS)

    Schaetzler, H.P.

    1978-01-01

    The γ-desorption method has been used in the early diagnosis of dry rot in trees. The attenuation of a 60 keV γ-beam ( 241 Am) has been measured on eleven healthy spruce disks. It is seen that early diagnostic of rotten trees is limited by natural density variation of the wood itself, but for a 95% confidence level that the wood is diseased, a tree must have an average of less than 0.59 g./cm 3 . (Auth/C.F.)

  12. Stratified B-trees and versioning dictionaries

    OpenAIRE

    Twigg, Andy; Byde, Andrew; Milos, Grzegorz; Moreton, Tim; Wilkes, John; Wilkie, Tom

    2011-01-01

    A classic versioned data structure in storage and computer science is the copy-on-write (CoW) B-tree -- it underlies many of today's file systems and databases, including WAFL, ZFS, Btrfs and more. Unfortunately, it doesn't inherit the B-tree's optimality properties; it has poor space utilization, cannot offer fast updates, and relies on random IO to scale. Yet, nothing better has been developed since. We describe the `stratified B-tree', which beats all known semi-external memory versioned B...

  13. Electroweak unification and tree unitarity

    International Nuclear Information System (INIS)

    Horejsi, J.

    1993-01-01

    The monograph is an unconventional introduction into the theory of unification of weak and electromagnetic interactions, which is conceptually different from the exposition presented in standard textbooks. A detailed explanation is given of the way to the standard model of electroweak interactions which is based on a straightforward application of the requirement of renormalizability of the perturbation series expansion. The procedure to derive the model is interesting as it demonstrates the necessity of introducing vector bosons and Yang-Mills type interactions and at least one elementary scalar boson to obtain a renormalizable theory of weak and electromagnetic interactions. The book is divided into 5 chapters: introduction, problems encountered in a Fermi type theory, the intermediate vector boson, electrodynamics of vector bosons, tree unitarity, and electroweak interactions. Each chapter is completed with exercise problems to be solved by the reader. The text is supplemented with a number of appendices. The monograph is aimed at undergraduate and postgraduate students as well as at physicists interested in the theory of elementary particles. (Z.J.)

  14. Heterogeneous Compression of Large Collections of Evolutionary Trees.

    Science.gov (United States)

    Matthews, Suzanne J

    2015-01-01

    Compressing heterogeneous collections of trees is an open problem in computational phylogenetics. In a heterogeneous tree collection, each tree can contain a unique set of taxa. An ideal compression method would allow for the efficient archival of large tree collections and enable scientists to identify common evolutionary relationships over disparate analyses. In this paper, we extend TreeZip to compress heterogeneous collections of trees. TreeZip is the most efficient algorithm for compressing homogeneous tree collections. To the best of our knowledge, no other domain-based compression algorithm exists for large heterogeneous tree collections or enable their rapid analysis. Our experimental results indicate that TreeZip averages 89.03 percent (72.69 percent) space savings on unweighted (weighted) collections of trees when the level of heterogeneity in a collection is moderate. The organization of the TRZ file allows for efficient computations over heterogeneous data. For example, consensus trees can be computed in mere seconds. Lastly, combining the TreeZip compressed (TRZ) file with general-purpose compression yields average space savings of 97.34 percent (81.43 percent) on unweighted (weighted) collections of trees. Our results lead us to believe that TreeZip will prove invaluable in the efficient archival of tree collections, and enables scientists to develop novel methods for relating heterogeneous collections of trees.

  15. Posbist fault tree analysis of coherent systems

    International Nuclear Information System (INIS)

    Huang, H.-Z.; Tong Xin; Zuo, Ming J.

    2004-01-01

    When the failure probability of a system is extremely small or necessary statistical data from the system is scarce, it is very difficult or impossible to evaluate its reliability and safety with conventional fault tree analysis (FTA) techniques. New techniques are needed to predict and diagnose such a system's failures and evaluate its reliability and safety. In this paper, we first provide a concise overview of FTA. Then, based on the posbist reliability theory, event failure behavior is characterized in the context of possibility measures and the structure function of the posbist fault tree of a coherent system is defined. In addition, we define the AND operator and the OR operator based on the minimal cut of a posbist fault tree. Finally, a model of posbist fault tree analysis (posbist FTA) of coherent systems is presented. The use of the model for quantitative analysis is demonstrated with a real-life safety system

  16. tree composition and distribution in federal university

    African Journals Online (AJOL)

    Tersor

    types. Data were analyzed using descriptive statistics. A total of 52 tree species in 48 ... the highest number of species, most of the species were juvenile species. ... sustainable use methods throughout Africa to ..... App. Biosc.67.5437-5448.

  17. Tree-grass interactions in savannas

    CSIR Research Space (South Africa)

    Scholes, RJ

    1997-01-01

    Full Text Available Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody and gramineous plants interact by many mechanisms, some negative (competition) and some positive (facilitation). The strength and sign...

  18. Multisites Coordination in Shared Multicast Trees

    National Research Council Canada - National Science Library

    Dommel, H-P; Garcia-Luna-Aceves, J. J

    1999-01-01

    .... The protocol supports Internet-wide coordination for large and highly interactive groupwork, relying on transmission of coordination directives between group members across a shared end-to-end multicast tree...

  19. Community assessment of tropical tree biomass

    DEFF Research Database (Denmark)

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

    2015-01-01

    Background REDD+ programs rely on accurate forest carbon monitoring. Several REDD+ projects have recently shown that local communities can monitor above ground biomass as well as external professionals, but at lower costs. However, the precision and accuracy of carbon monitoring conducted by local...... 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...... measurement, with special attention given to large and odd-shaped trees. A better understanding of traditional classification systems and concepts is required for local tree identifications and wood density estimates to become useful in monitoring of biomass and tree diversity....

  20. Constructing phylogenetic trees using interacting pathways.

    Science.gov (United States)

    Wan, Peng; Che, Dongsheng

    2013-01-01

    Phylogenetic trees are used to represent evolutionary relationships among biological species or organisms. The construction of phylogenetic trees is based on the similarities or differences of their physical or genetic features. Traditional approaches of constructing phylogenetic trees mainly focus on physical features. The recent advancement of high-throughput technologies has led to accumulation of huge amounts of biological data, which in turn changed the way of biological studies in various aspects. In this paper, we report our approach of building phylogenetic trees using the information of interacting pathways. We have applied hierarchical clustering on two domains of organisms-eukaryotes and prokaryotes. Our preliminary results have shown the effectiveness of using the interacting pathways in revealing evolutionary relationships.