WorldWideScience

Sample records for camaldulenis tree leaves

  1. Computer Vision Classification of Leaves from Swedish Trees

    OpenAIRE

    Söderkvist, Oskar

    2001-01-01

    The aim of this master thesis is to classify the tree class from an image of a leaf with a computer vision classiffication system. We compare different descriptors that will describe the leaves different features. We will also look at different classiffication models and combine them with the descriptors to build a system hat could classify the different tree classes.

  2. Expanding leaves of mature deciduous forest trees rapidly become autotrophic.

    Science.gov (United States)

    Keel, Sonja G; Schädel, Christina

    2010-10-01

    Emerging leaves in evergreen tree species are supplied with carbon (C) from the previous year's foliage. In deciduous trees, no older leaves are present, and the early phase of leaf development must rely on C reserves from other tissues. How soon developing leaves become autotrophic and switch from being C sinks to sources has rarely been studied in mature forest trees, and simultaneous comparisons of species are scarce. Using a canopy crane and a simple (13)CO(2)-pulse-labelling technique, we demonstrate that young leaves of mature trees in three European deciduous species (Fagus sylvatica L., Quercus petraea (Matt.) Liebl., Tilia platyphyllos Scop.) start assimilating CO(2) at a very early stage of development (10-50% expanded). One month after labelling, all leaves were still strongly (13)C enriched, suggesting that recent photosynthates had been incorporated into slow turnover pools such as cellulose or lignin and thus had contributed to leaf growth. In line with previous studies performed at the same site, we found stronger incorporation of recent photosynthates into growing tissues of T. platyphyllos compared with F. sylvatica and Q. petraea. Non-structural carbohydrate (NSC) concentrations analysed for one of the three study species (F. sylvatica) showed that sugar and starch pools rapidly increased during leaf development, suggesting that newly developed leaves soon produce more NSC than can be used for growth. In conclusion, our findings indicate that expanding leaves of mature deciduous trees become C autonomous at an early stage of development despite the presence of vast amounts of mobile carbohydrate reserves. PMID:20688879

  3. Iron in olive tree leaves in the Mediterranean area

    International Nuclear Information System (INIS)

    Technique of X-ray fluorescence by dispersion in energy was used in order to study a phytopathology named 'sooty mould' in olive tree layers in the Mediterranean area. Samples studied included leaves which were infected and non-infected by sooty mould. Energy depressive X-ray fluorescence showed a significant increase in the amount of Fe in the affected leaves when compared to leaves that don't have this pattern of black material. A treatment for this condition based on a method that deprives these organisms of the Fe that they apparently need to survive was suggested. The average Fe concentration obtained for the infected olive tree leaves was 80 ppm, while the non-infected ones showed no measurable Fe presence. (author)

  4. Seasonality of nutrients in leaves and fruits of apple trees

    Directory of Open Access Journals (Sweden)

    Nachtigall Gilmar Ribeiro

    2006-01-01

    Full Text Available The nutrient accumulation curves of apple trees are good indicators of plant nutrient demand for each developmental stage. They are also a useful tool to evaluate orchard nutritional status and to estimate the amount of soil nutrient removal. This research aimed at evaluating the seasonality of nutrients in commercial apple orchards during the agricultural years of 1999, 2000, and 2001. Therefore, apple tree leaves and fruits of three cultivars 'Gala', 'Golden Delicious' and 'Fuji' were weekly collected and evaluated for fresh and dry matter, fruit diameter and macronutrient (N, P, K, Ca and Mg and micronutrient (B, Cu, Fe, Mn, and Zn concentrations. Leaf and fruit sampling started one or two weeks after full bloom, depending on the cultivar, and ended at fruit harvest or four weeks later (in the case of leaf sampling. In general, leaf concentrations of N, P, K, Cu, and B decreased; Ca increased; and Mg, Fe, Mn, and Zn did vary significantly along the plant vegetative cycle. In fruits, the initial nutrient concentrations decreased quickly, undergoing slow and continuous decreases and then remaining almost constant until the end of fruit maturation, indicating nutrient dilution, once the total nutrient accumulation increased gradually with fruit growth. Potassium was the nutrient present in highest quantities in apple tree fruits and thus, the most removed from the soil.

  5. Stomatal control of water use in olive tree leaves

    OpenAIRE

    Fernández Luque, José Enrique; Moreno Lucas, Félix; Girón Moreno, Ignacio F.; Blázquez, O. M.

    1997-01-01

    Little is known about the strategies used by olive trees to overcome the long dry periods typical of the areas where they are cropped. This makes it difficult to optimize the water supply in orchards. To study the control of water consumption by olive trees, measurements of leaf water potential (Ψ) and stomatal conductance to H2O (g) were made on 26-year-old Manzanillo olive trees under three irrigation treatments. The first treatment provided enough water to cover the crop water demand, the ...

  6. Cultivation of Pleurotus floridaon Forest and Agricultural Wastes By Leaves of Tree and Wood Waste

    OpenAIRE

    Hüseyin SİVRİKAYA

    1999-01-01

    Some forest and agricultural wastes of Eastern Black Sea Region of Turkey were subjected to mushroom ( Pleurotus florida) cultivation in this study. 1:1, 1:3 and 3:1 (w:w) mixtures were prepared mainly by tree leaves wood wastes of timber work shops, cupola of nut trees (NC) and leaves (NL), corn stalks (CS), waste tea leaves (WTL) of tea factories, wheat straw (WS) and waste paper(WP). P.floridaof which the strain was numbered darmycel by Fungi Perfect co. (USA) was used in inoculations of p...

  7. CHEMICAL COMPOSITION AND IN VITRO GAS PRODUCTION KINETICS OF SOME TREE LEAVES OBTAINED IN THE MEDITERRANEAN REGION OF TURKEY

    OpenAIRE

    BOGA, Mustafa

    2014-01-01

    This study was carried out to determine the potential nutritive value and in vitro gas production (IVGP) kinetics of some tree leaves. In this study four different tree foliages (orchid tree -Bauhinia purpurea L. (Fabaceae), eucalyptus -Eucalyptus camaldulensis, yellow oleander tree -Thevetia peruviana and pepper tree -Schinus molle) were used. The gas production of leaves over time was recorded at 3, 6, 9, 12, 24, 48, 72 and 96 h after incubation. The results of the present study suggested t...

  8. Air pollution survey in Rome using magnetic properties of tree leaves

    Science.gov (United States)

    Moreno, E.; Sagnotti, L.; Winkler, A.; Dinarès Turell, J.; Cascella, A.

    2003-04-01

    We present the results of a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves from Platanus sp. and Quercus Ilex. A Platanus sp. sampling campaign was effectuated in October 2001 and 5 Quercus Ilex monthly sampling campaigns from April to August 2002. Comparison between different tree species from the same location pointed out that leaves of the evergreen oak Quercus Ilex, with an average life-span of 3 years, present much higher magnetic intensities that leaves from Platanus sp. and other deciduous species common in Rome, suggesting that leaves accumulate magnetic pollutants during their whole life-span. Low-coercivity minerals of sub-micron size constantly dominate the magnetic fraction of the dusts accumulated on leaves. However, concentration and size of magnetic particles on leaves appear to be controlled by vehicular traffic emissions. In fact, distribution maps of magnetic susceptibility and isothermal remanence (IRM) from leaves collected in selected study areas in the south of Rome show distinct patterns that follow the distribution of green areas and main roads. High concentration and relatively larger grain-sizes of magnetic particles were observed in trees located along roads with high vehicle traffic and in the vicinity of railways. We found that the values of susceptibility and IRM along the main roads were about 10 times higher than in parks. Moreover, we also observed a decrease in concentration and grain size of magnetic particles with distance from the roadside, reinforcing the conclusion that the main sources of fine magnetic dusts adsorbed and deposited on the tree leaves are vehicle emissions. The results indicate that a magnetic survey of tree leaves, which is relatively rapid and inexpensive, may be used in addition to the classical air quality monitoring systems to identify and delineate high-polluted areas in urban environments.

  9. Assessment of Tree Leaves Flakes Mixed with Crude Glycerol as a Bioenergy Source

    Science.gov (United States)

    Hilal-AlNaqbi, Ali; Al-Omari, Salah B.; Selim, Mohamed Y. E.

    2016-01-01

    The gasification and combustion of dry tree leaves and the cogasification of dry tree leaves soaking crude glycerol were studied experimentally. An updraft fixed bed gasification and combustion system was built. The operation was conducted at different air to fuel ratios. Results show more stable combustion and more effective heat transfer to furnace walls for the cases when tree leaves flakes are mixed with 20 percent (on mass basis) of crude glycerol, as compared with the case when only dry tree leaves are used as fuel. TGA analysis was also conducted for the two fuels used under both air and nitrogen environments. For the crude glycerol, four phases of pyrolysis and gasification were noticed under either of the two surrounding gaseous media (air or nitrogen). For the dry tree leaves, the pyrolysis under nitrogen shows only a simple smooth pyrolysis and gasification curve without showing the different distinct phases that were otherwise identified when the pyrolysis is conducted under air environment. Moreover, the air TGA results lead to more gasification due to the char oxidation at high temperatures. DTG results are also presented and discussed. PMID:27413749

  10. Assessment of Tree Leaves Flakes Mixed with Crude Glycerol as a Bioenergy Source

    Directory of Open Access Journals (Sweden)

    Ali Hilal-AlNaqbi

    2016-01-01

    Full Text Available The gasification and combustion of dry tree leaves and the cogasification of dry tree leaves soaking crude glycerol were studied experimentally. An updraft fixed bed gasification and combustion system was built. The operation was conducted at different air to fuel ratios. Results show more stable combustion and more effective heat transfer to furnace walls for the cases when tree leaves flakes are mixed with 20 percent (on mass basis of crude glycerol, as compared with the case when only dry tree leaves are used as fuel. TGA analysis was also conducted for the two fuels used under both air and nitrogen environments. For the crude glycerol, four phases of pyrolysis and gasification were noticed under either of the two surrounding gaseous media (air or nitrogen. For the dry tree leaves, the pyrolysis under nitrogen shows only a simple smooth pyrolysis and gasification curve without showing the different distinct phases that were otherwise identified when the pyrolysis is conducted under air environment. Moreover, the air TGA results lead to more gasification due to the char oxidation at high temperatures. DTG results are also presented and discussed.

  11. Biomonitoring of traffic air pollution in Rome using magnetic properties of tree leaves

    Science.gov (United States)

    Moreno, Eva; Sagnotti, Leonardo; Dinarès-Turell, Jaume; Winkler, Aldo; Cascella, Antonio

    We report a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves. In a first step, magnetic properties of leaves from different tree species from the same location were compared. It was observed that leaves of evergreen species, like Quercus ilex, present much higher magnetic intensities than those of deciduous species, like Platanus sp., suggesting that leaves accumulate magnetic pollutants during their whole lifespan. In a second step, leaves from Q. ilex and Platanus sp. trees, both very common in Rome, have been used to monitor traffic emission pollution in two different periods. A Platanus sp. sampling campaign was undertaken in October 2001, at the end of the seasonal vegetational cycle, and 5 Q. ilex monthly sampling campaigns from April to August 2002. The strong difference observed in the magnetic susceptibility from leaves collected in green areas and roads allowed the realization of detailed pollution distribution maps from the south of Rome. Magnetic properties indicate that high concentrations and relatively larger grain-sizes of magnetic particles are observed in trees located along roads with high vehicle traffic and in the vicinity of railways. The decrease in concentration and grain size of magnetic particles with distance from the roadside confirms that magnetic properties of leaves are related to air pollution from vehicle emissions. The results indicate that a magnetic survey of tree leaves, which is relatively rapid and inexpensive, may be used in addition to the classical air quality monitoring systems to identify and delineate high-polluted areas in urban environments.

  12. Dynamics of nitrogen nutrition of coexisting dominant trees in mixed broad-leaved/Korean pine forest

    Institute of Scientific and Technical Information of China (English)

    Li Yuwen

    1999-01-01

    Chemical analysis of ammonium, nitrate and total nitrogen in tree leaves and roots and an in-vivo bioassay for nitrate reductase activity (NRA) were used to monitor the seasonal variations in nitrogen assimilation among four coexisting dominant tree species, including Pinus koraiensis, Ti/ia amurensis, Fraxinus mandshurica and Acer mono, in a virgin mixed broad-leaved/Korean pine (Pinus koraiensis) forest. The soil study included individual horizons of L+F (0-5 cm), Ah (5-11 cm) and Aw (11-25 cm). All four species had nitrate and ammonium in their roots and leaves, and also NRA in leaves. This indicated that these coexisting species were adapted to ammonium + nitrate nutrition. A negative correlation existed between nitrate use and ammonium use. Ammonium concentration was higher than that of nitrate in tree leaves and roots, and also in soils, which indicated climax woody species had a relative preference for ammonium nutrition. There was a positive relationship between tree nitrogen nutrition use and soil nitrogen nutrient supply. Utilization of ammonium and nitrate as well as the seasonal patterns differed significantly between the species. Peaks of ammonium, nitrate, NRA and total nitrogen in one species were therefore not necessarily synchronous with peaks in other species, and which indicated a species-specific seasonal use of nitrogen. The species-specific temporal differentiation in nitrogen use might reduce the competition between co-existing species and may be an important mechanism promoting stability of virgin mixed broad-leaved∥Korean pine forest.

  13. Trace element content in urban tree leaves and SEM-EDAX characterization of deposited particles

    OpenAIRE

    Tomašević Milica; Aničić Mira

    2010-01-01

    Leaves of common deciduous trees: Aesculus hippocastanum and Tilia spp. from three parks within the urban area of Belgrade (Serbia) were studied as biomonitors of trace elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, and Pb) air pollution. Using a scanning SEM-EDAX, the size, size distribution, morphology and chemical composition of individual particles were examined on adaxial and abaxial surfaces of the leaves. Morphological and chemical composition indicated that the most abundant particles...

  14. [Tree uprooting of coniferous-broad leaved Korean pine mixed forest in Lesser Khingan Mountains, China].

    Science.gov (United States)

    Ge, Xiao-wen; Hou, Jie-jian; Wang, Li-hai; Wang, Xing-long; Rong, Bin-bin

    2016-02-01

    The morphological parameters, root wad indexes and site conditions of 127 uprooting trees from 76 plots (20 mx20 m) in Lesser Khingan coniferous-broad leaved Korean pine mixed forest were measured. Then the influencing factors of uprooting differences and the relationship between uprooting trees and disturbed soil were analyzed. Results showed that the number of uprooting trees varied significantly among species. Abies nephrolepis suffered the most serious uprooting damage, then Pinus koraiensis, and Ulmus spp. the least. Deciduous species had a stronger uprooting-resistant capacity than broad-leaved species. With the increase of tree DBH and height, tree' s uprooting resistance declined rapidly first and then was gradually enhanced, and finally reached the minimum at diameter class of 20 cm and height class of 14 m, respectively. The smaller the taper degree and projected area of crown were, the stronger the uprooting resistance was. Uprooting rate was negatively correlated with stand density. Trees lying in wet ground, flat terrain, medium low altitude area and windward slope had a greater risk of uprooting. There were significant positive correlation between the depth, area and volume of disturbed soil and the DBH, height, volume of uprooting trees. PMID:27396108

  15. Contribution to biomonitoring of some trace metals by deciduous tree leaves in urban areas.

    Science.gov (United States)

    Tomasević, M; Vukmirović, Z; Rajsić, S; Tasić, M; Stevanović, B

    2008-02-01

    Leaves of the deciduous tree species, horse chestnut (Aesculus hippocastanum L.) and Turkish hazel (Corylus colurna L.) were used as accumulative biomonitors of trace metal pollution in the urban area of Belgrade. Using differential pulse anodic stripping voltametry, trace metal concentrations (Pb, Cu, Zn, Cd) were determined at the single leaf level (ten leaves per species, per month), during two successive years with markedly different atmospheric level of trace metals. Increased trace metal concentrations in the leaves of A. hippocastanum reflected elevated atmospheric trace metal pollution, whereas C. colurna L. did not respond accordingly. The contents of Pb and Zn in soil over the same period also followed this trend. Anatomical analyses, in young as well as in old leaves of both species, indicated typical foliar injuries of plants exposed to stressful air conditions. Water relations that correspond to leaf age may have contributed to the considerable trace metal accumulation in leaves. PMID:17505898

  16. Preliminary study of elemental composition in tree leaves for using as bio monitor for air pollution

    International Nuclear Information System (INIS)

    The use of plant tissue as biological monitor of air pollution has been of interest world wild. The study on chemical composition of such biological monitor may provide important information on the levels and pathways of a variety of pollutants including heavy metals and trace toxic elements in atmosphere. The appropriate bio monitors are such as herbaceous plants, tree leaves, bryophytes and lichens, with their possible advantages and/or limitations. In this research an investigation of element composition in leaves was performed. The technique of Instrument Neutron Activation Analysis (INAA) was developed to determine heavy metal and trace elements in 8 species of tree leaves collected from 3 different locations. From the experiments, it was found that content of elements might vary depending on species and environment. Some specific elements are discussed and compared in this report

  17. Determination of feed value of cherry, apricot and almond tree leaves in ruminant using in situ method

    Directory of Open Access Journals (Sweden)

    S. Mahmoudi

    2012-09-01

    Full Text Available In the present study, chemical composition and in situ rumen dry matter degradability (DMD of some tree species (cherry, apricot and almond tree leaves were determined. Crude protein (CP concentration varied from 6.76% for almond tree to 2.76% for cherry tree, neutral detergent fiber (NDF and acid detergent fiber (ADF, from 29.2, 20.8% for apricot tree to 20.8 and 15.8% for almond tree leaves respectively. Polyphenol and tannin composition measured from 3.49, 1.2% for almond tree to 1.51 and 0.61% for apricot tree, respectively. In situ rumen degradability was carried out in three fistulaed Taleshi native male cattle which were incubated at times of 0, 4, 8, 16, 24, 48, 72 and 96-hour. Almond leaves had higher potential degradation (a+b for dry matter (92.37% and cherry leaves showed lower potential degradation (84.12%, respectively. Effective rumen degradable dry matter at rate of 0.05/h varied from 69.86% for almond tree to 52.20% for cherry leaves. Results showed that the almond leaves were higher in nutritive value than cherry and apricot leaves. Therefore, almond tree leaves could be used with forage in ruminant diets to reduce cost of animals feed requirements. Overall, it seemed that the tree leaves used in this study, had a higher nutritive value in ruminant’s nutrition, however more experiments are needed for an accurate determination of nutritional values of these resources.

  18. Optical solar energy adaptations and radiative temperature control of green leaves and tree barks

    Energy Technology Data Exchange (ETDEWEB)

    Henrion, Wolfgang; Tributsch, Helmut [Department of Si-Photovoltaik and Solare Energetik, Hahn-Meitner-Institut Berlin, 14109 Berlin (Germany)

    2009-01-15

    Trees have adapted to keep leaves and barks cool in sunshine and can serve as interesting bionic model systems for radiative cooling. Silicon solar cells, on the other hand, loose up to one third of their energy efficiency due to heating in intensive sunshine. It is shown that green leaves minimize absorption of useful radiation and allow efficient infrared thermal emission. Since elevated temperatures are detrimental for tensile water flow in the Xylem tissue below barks, the optical properties of barks should also have evolved so as to avoid excessive heating. This was tested by performing optical studies with tree bark samples from representative trees. It was found that tree barks have optimized their reflection of incoming sunlight between 0.7 and 2 {mu}m. This is approximately the optical window in which solar light is transmitted and reflected by green vegetation. Simultaneously, the tree bark is highly absorbing and thus radiation emitting between 6 and 10 {mu}m. These two properties, mainly provided by tannins, create optimal conditions for radiative temperature control. In addition, tannins seem to have adopted a function as mediators for excitation energy towards photo-antioxidative activity for control of radiation damage. The results obtained are used to discuss challenges for future solar cell optimization. (author)

  19. PIXE analysis of tree leaves as a possible comparative integral monitor of particulates in urban areas

    International Nuclear Information System (INIS)

    The possibility of obtaing integral comparative data for particulate distribution in urban areas from PIXE analysis of tree leaves is discussed in relation to the leaf gross anatomy, to the diffusion of selected tree species in such areas and to the implementation of experimental techniques necessary to make PIXE analysis effective. Multielemental scans were performed on a small set samples; results are compared to PIXE analysis of typical urban aerosols. The validity of the method and the criteria for yearly relative comparisons of different areas are discissed

  20. Nutritional value of tree leaves for livestock from a semi-hilly arid region of India

    International Nuclear Information System (INIS)

    Samples of 13 species of forest tree leaves growing in the semi-hilly arid zone of Punjab State in India were collected at 30 day intervals over 12 months, in order to assess their nutritional value for livestock. The ground samples were pooled for four seasons: dry hot, hot humid, fall, and winter. The data were arranged in a 13 x 4 factorial design for analysis. For tannin fractionation, leaves of 12 species containing more than 3.5% total phenols were selected and data were analysed within a 12 x 12 factorial design. The chemical composition, irrespective of the season, revealed that Leucaena had the highest crude protein (CP, 220 g/kg dry matter). Globulin was the major protein fraction in most of the leaves. The lowest concentration of neutral detergent fibre (NDF) was in Morus, Acacia and Grewea spp. Fibre and lignin content increased during the fall and winter. The leaves of Grewea, Morus, Leucaena, Carrisa and Acacia were rich in Ca, P and most of the trace elements. The total phenolics ranged between 38 (Toona) and 169 g/kg DM (Anogeisus). The leaves of Anogeisus had the highest concentration of hydrolysable tannins (16.9%) whereas those of Carrisa had highest condensed tannins (4.6%). The condensed tannins (>3%) were negatively correlated to the digestibility of dry matter (DM), NDF and CP. The digestion kinetic parameters for DM, NDF and CP revealed that leaves of Morus alba, Zizyphus and Ehretia were most degradable. The minimum rumen fill values also revealed that leaves of Grewea, Azadirachta, Morus, Ehretia and Leucaena had higher potential for voluntary DM intake, especially compared to leaves of Ougeinia, Zizyphus xylopyrus, Dodonea and Carrisa. During winter, most of the leaves had a low potentially degradable fraction, with a low rate of degradation. Screening leaves by the in vitro gas production technique suggested that leaves of Melia azedarach, Azadirachta indica, Morus alba and Leucaena leucocephala were potential feeds for ruminants

  1. Control of gaseous pollution via the leaves of non-edible trees

    Science.gov (United States)

    Al-Maliky, S. J. B.

    2015-11-01

    The accelerated increase of the use of various transportation means, industrial machinery and other power consuming technologies has led to tremendous degradation of outdoor air quality all around the world. Green solution was tested here as an innovative gas control mean via non edible Myrtus communis green leaves as natural sorption media. Statistical analyses were applied in order to examine the correlation between various parameters of this study. The tests of gas records around the tree that was targeted by a gas stream of 5 KW power generators have demonstrated an excellent gas control role of the green leaves, with average efficiencies of about 75% and 82% for the removal of Nitrogen Dioxide and Carbon Monoxide, respectively. An interesting finding of this research was that the sorption role of green leaves has promoted their sizes and Chlorophyll Content Index.

  2. Dissipation of excess excitation energy of the needle leaves in Pinus trees during cold winters

    Science.gov (United States)

    Zhang, AO; Cui, Zhen-Hai; Yu, Jia-Lin; Hu, Zi-Ling; Ding, Rui; Ren, Da-Ming; Zhang, Li-Jun

    2016-05-01

    Photooxidative damage to the needle leaves of evergreen trees results from the absorption of excess excitation energy. Efficient dissipation of this energy is essential to prevent photodamage. In this study, we determined the fluorescence transients, absorption spectra, chlorophyll contents, chlorophyll a/b ratios, and relative membrane permeabilities of needle leaves of Pinus koraiensis, Pinus tabulaeformis, and Pinus armandi in both cold winter and summer. We observed a dramatic decrease in the maximum fluorescence (F m) and substantial absorption of light energy in winter leaves of all three species. The F m decline was not correlated with a decrease in light absorption or with changes in chlorophyll content and chlorophyll a/b ratio. The results suggested that the winter leaves dissipated a large amount of excess energy as heat. Because the cold winter leaves had lost normal physiological function, the heat dissipation depended solely on changes in the photosystem II supercomplex rather than the xanthophyll cycle. These findings imply that more attention should be paid to heat dissipation via changes in the photosystem complex structure during the growing season.

  3. Trace element content in urban tree leaves and SEM-EDAX characterization of deposited particles

    Directory of Open Access Journals (Sweden)

    Tomašević Milica

    2010-01-01

    Full Text Available Leaves of common deciduous trees: Aesculus hippocastanum and Tilia spp. from three parks within the urban area of Belgrade (Serbia were studied as biomonitors of trace elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, and Pb air pollution. Using a scanning SEM-EDAX, the size, size distribution, morphology and chemical composition of individual particles were examined on adaxial and abaxial surfaces of the leaves. Morphological and chemical composition indicated that the most abundant particles were soot and dust with minor constituents such as Pb, Zn, Ni, V, Cd, Ti, As, and Cu. Total element concentrations in the leaves were determined by ICP-OES and ICP-MS. This investigation included spatial, seasonal, and temporal variations in leaves of the selected species. The leaves of A. hippocastanum showed a significantly higher elements concentration and more consistency in trend of element accumulation during the vegetation season in the period 2002-2006 than Tilia spp., so it may be considered as a more suitable species for the assessment of trace element atmospheric pollution, especially Pb and Cu which correlated with the bulk deposition data.

  4. ENVIRONMENTAL MONITORING USING LINDEN TREE LEAVES AS NATURAL TRAPS OF ATMOSPHERIC DEPOSITION: A PILOT STUDY IN TRANSILVANIA, ROMANIA

    OpenAIRE

    MIHÁLY BRAUN; ZITA MARGITAI; ALBERT TÓTH; MARTINE LEERMAKERS

    2007-01-01

    Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have been widely used as indicator of atmospheric pollutions and they are effective alternatives to the moreusual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition. Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate th...

  5. Framework for using deciduous tree leaves as biomonitors for intraurban particulate air pollution in exposure assessment.

    Science.gov (United States)

    Gillooly, Sara E; Shmool, Jessie L Carr; Michanowicz, Drew R; Bain, Daniel J; Cambal, Leah K; Shields, Kyra Naumoff; Clougherty, Jane E

    2016-08-01

    Fine particulate matter (PM2.5) air pollution, varying in concentration and composition, has been shown to cause or exacerbate adverse effects on both human and ecological health. The concept of biomonitoring using deciduous tree leaves as a proxy for intraurban PM air pollution in different areas has previously been explored using a variety of study designs (e.g., systematic coverage of an area, source-specific focus), deciduous tree species, sampling strategies (e.g., single day, multi-season), and analytical methods (e.g., chemical, magnetic) across multiple geographies and climates. Biomonitoring is a low-cost sampling method and may potentially fill an important gap in current air monitoring methods by providing low-cost, longer-term urban air pollution measures. As such, better understanding of the range of methods, and their corresponding strengths and limitations, is critical for employing the use of tree leaves as biomonitors for pollution to improve spatially resolved exposure assessments for epidemiological studies and urban planning strategies. PMID:27450373

  6. Small branches of olive tree: a source of biophenols complementary to olive leaves.

    Science.gov (United States)

    Japón-Lujan, R; Luque de Castro, M D

    2007-05-30

    The extraction of biophenols (BPs) from small branches (fibrous softwood) of olive tree accelerated by microwave assistance is proposed for the first time. Under optimal working conditions, no further extraction of the target analytes was achieved after 10 min, so complete removal of them within this interval was assumed (amounts ca. to 19000, 1000, 2000, 900, and 700 mg/kg of oleuropein, verbascoside, tyrosol, alpha-taxifolin, and hydroxytyrosol, respectively; the three last BPs are absent in branch-free olive leaves). The extracts required no cleanup or concentration prior to injection into a chromatograph-photodiode array detector assembly for individual separation-quantification. Extraction from this raw material was also implemented in continuous and discontinuous-continuous extractors using ultrasound assistance and superheated liquids, respectively, as auxiliary energies, and the results were compared with those obtained by microwave-assisted extraction. The simultaneous extraction of small branches and leaves from olive tree provided extracts with a higher variety of BPs, but either extracts richer in oleuropein and verbascoside without tyrosol, alpha-taxifolin, and hydroxytyrosol or rich in these three BPs can be obtained by separate extraction of leaves and branches, respectively. PMID:17488032

  7. Estimation of water content in the leaves of fruit trees using infra-red images

    International Nuclear Information System (INIS)

    A method was developed to evaluate water contents of fruit trees using infra-red photography. The irrigation of potted satsuma mandarin trees and grapevines was suppressed to induce water stress. During the drought treatment the leaf edges of basal parts of the shoots of grapevines became necrotic and the area of necrosis extended as the duration of stress increased. Necrosis was clearly distinguished from the viable areas on infra-red images. In satsuma mandarin, an abscission layer formed at the basal part of the petiole, then the leaves fell. Thus, detailed analysis was indispensable for detecting of the leaf water content. After obtaining infra-red images of satsuma mandarin leaves with or without water stress, a background treatment (subtraction of the background image) was performed on the images, then the average brightness of the leaf was determined using image analyzing software (Image Pro-plus). Coefficient correlation between the water status index using the infra-red camera and water content determined from dry weight and fresh weight of leaves was significant (r = 0.917 for adaxial surface data and r = 0.880 for abaxial surface data). These data indicate that infra-red photography is useful for detecting the degree of plant water stress

  8. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    Energy Technology Data Exchange (ETDEWEB)

    Olbrich, Maren, E-mail: maren.olbrich@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Gerstner, Elke; Bahnweg, Guenther [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Matyssek, Rainer [Technische Universitaet Muenchen, Ecophysiology of Plants, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Heller, Werner; Ernst, Dieter [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  9. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    International Nuclear Information System (INIS)

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  10. Frequency distribution of zinc in leaves with and without zinc-deficiency symptoms, all collected from a single orange tree

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, A. (Univ. of Caifornia, Los Angeles); Alexander, G.V.; Kinnear, J.; Procopiou, J.; Haritou-Andriotaki, A.; Papanicolaou, X.

    1982-07-01

    Leaves with zinc-deficiency symptoms had a lower Zn concentration than corresponding leaves without symptoms and of the same age from the same orange (Citrus senensis L.) tree on sour orange (C. aurantium L.) rootstock grown in Rhodes, Greece. There was considerable overlap, however, with the frequency distribution of each group approximating a normal curve. But both kinds of leaves combined showed a more normal distribution. Some leaves with symptoms had higher zinc concentrations than some without symptoms. There was a threefold range in Zn concentration for each group of leaves. Zinc-deficient leaves had less phosphorus, calcium, and manganese and more iron, aluminum, silicon, and titanium (the so-called dust elements) than did leaves with no deficiency symptoms. Some of these elements gave normal curves for both Zn-deficient and non-Zn-deficient leaves.

  11. Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2016-01-01

    Full Text Available Subtropical evergreen broad-leaved forest (EBLF is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

  12. Study of the anomalous presence of iron in olive trees leaves by energy dispersion X-ray fluorescence

    International Nuclear Information System (INIS)

    In this work, we made use of the technique of X-ray fluorescence for dispersion in energy, to study a phytopathology denominated 'sooty mould' on leaves of Olive trees of Mediterranean area. The Olive trees are quite common and of great economical value in that area,especially in the island of Sardegna in Italy, where this work was developed, for treating one of the income main sources of the local economy. We observed a correlation between the elements Fe and Ca among infected leaves of Olive trees and not infected that is: leaves infected by the sooty mould present a large concentration of Fe and a low concentration of Ca when compared to the leaves not infected by the sooty mould. The oxidation state of Fe was determined by Moessbauer spectroscopy that revealed that this was Fe3+. (author)

  13. Chemometrics in biomonitoring: Distribution and correlation of trace elements in tree leaves.

    Science.gov (United States)

    Deljanin, Isidora; Antanasijević, Davor; Bjelajac, Anđelika; Urošević, Mira Aničić; Nikolić, Miroslav; Perić-Grujić, Aleksandra; Ristić, Mirjana

    2016-03-01

    The concentrations of 15 elements were measured in the leaf samples of Aesculus hippocastanum, Tilia spp., Betula pendula and Acer platanoides collected in May and September of 2014 from four different locations in Belgrade, Serbia. The objective was to assess the chemical characterization of leaf surface and in-wax fractions, as well as the leaf tissue element content, by analyzing untreated, washed with water and washed with chloroform leaf samples, respectively. The combined approach of self-organizing networks (SON) and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) aided by Geometrical Analysis for Interactive Aid (GAIA) was used in the interpretation of multiple element loads on/in the tree leaves. The morphological characteristics of the leaf surfaces and the elemental composition of particulate matter (PM) deposited on tree leaves were studied by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) detector. The results showed that the amounts of retained and accumulated element concentrations depend on several parameters, such as chemical properties of the element and morphological properties of the leaves. Among the studied species, Tilia spp. was found to be the most effective in the accumulation of elements in leaf tissue (70% of the total element concentration), while A. hippocastanum had the lowest accumulation (54%). After water and chloroform washing, the highest percentages of removal were observed for Al, V, Cr, Cu, Zn, As, Cd and Sb (>40%). The PROMETHEE/SON ranking/classifying results were in accordance with the results obtained from the GAIA clustering techniques. The combination of the techniques enabled extraction of additional information from datasets. Therefore, the use of both the ranking and clustering methods could be a useful tool to be applied in biomonitoring studies of trace elements. PMID:26748000

  14. ENVIRONMENTAL MONITORING USING LINDEN TREE LEAVES AS NATURAL TRAPS OF ATMOSPHERIC DEPOSITION: A PILOT STUDY IN TRANSILVANIA, ROMANIA

    Directory of Open Access Journals (Sweden)

    MIHÁLY BRAUN

    2007-12-01

    Full Text Available Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have been widely used as indicator of atmospheric pollutions and they are effective alternatives to the moreusual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition. Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate the characteristics and sources of air pollutants. Tree leaves (Tilia tomentosa, Tilia cordata, Tilia platyphyllos were collected and used for the measurements. Elemental analyses were carried out by ICP-OES and ICP-MS. Principal component and discriminant analyses were used to characterizing and estimating the level of pollution. Settlements were grouped on the basis of discriminant function values. Multivariate comparison of chemical data ordered the settlements into 3 main groups, which showed a systematic geographic distribution.

  15. Indicating atmospheric sulfur by means of S-isotope in leaves of the plane, osmanthus and camphor trees

    International Nuclear Information System (INIS)

    Foliar δ34S values of three soil-growing plant species (Platanus Orientalis L., Osmanthus fragrans L. and Cinnamomum camphora) have been analyzed to indicate atmospheric sulfur. The foliar δ34S values of the three plant species averaged −3.11 ± 1.94‰, similar to those of both soil sulfur (−3.73 ± 1.04‰) and rainwater sulfate (−3.07 ± 2.74‰). This may indicate that little isotopic fractionation had taken place in the process of sulfur uptake by root or leaves. The δ34S values changed little in the transition from mature leaves to old/senescing leaves for both the plane tree and the osmanthus tree, suggestive of little isotope effect during sulfur redistribution in plant tissues. Significantly linear correlation between δ34S values of leaves and rainwater sulfate for the plane and osmanthus trees allowed the tracing of temporal variations of atmospheric sulfur by means of foliar sulfur isotope, while foliage δ34S values of the camphor is not an effective indicator of atmospheric sulfur. - Highlights: ► The δ34S values in plant leaves were similar to the average of rainwater. ► Little isotope effect was found during sulfur uptake by plant leaves. ► The foliage δ34S values are useful to indicate atmospheric sulfur. - Using foliage sulfur isotopes of soil growing plants to indicate atmospheric sulfur.

  16. Nitrogen content and nitrogen reserves in annual leaves and offshoots of apple trees undergoing foliar nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Gustavo Brunetto

    2012-11-01

    Full Text Available Foliar applications of nitrogen (N, when needed, have been used to supplement the fertilization of fruit trees through the soil. However, information on frequency effects, N amount to be applied, and the importance of increasing N content and N reserves in the leaves and offshoots are few. This paper aimed at evaluating the effect of foliar N applications on the N content and reserves in annual leaves and offshoots of apple trees. The study was carried out in an apple trees orchard (Eva cultivar, crop 2007/2008, in the experimental area of the Polytechnic College of Universidade Federal de Santa Maria (UFSM, in the town of Santa Maria, Rio Grande do Sul, Brazil, on a hydromorphic planosol. The treatments consisted of 1 and 2 foliar applications of 0; 1.11; 2.23; 3.31; 4.41; and 5.51g of N plant-1. The results showed that foliar N applications resulted in increased N contents in the whole leaves, especially up to the 8th day after application, but they do not affect N content in the annual offshoots. Nitrogen fertilization via the leaves did not increase the total content of amino acids and proteins in the annual whole leaves and offshoots

  17. Accumulation of sulfur and heavy metals in soil and tree leaves sampled from the surroundings of Tuncbilek Thermal Power Plant.

    Science.gov (United States)

    Cicek, A; Koparal, A S

    2004-11-01

    In this study, the quantities of sulfur and heavy metals, resulting from the Tuncbilek Thermal Power Plant (TPP) in Turkey, have been assessed in tree leaves and soil samples within a 10 km radius of the plant. Leaves of Salix alba L., Populus tremula L., Robinia pseudoacacia L., Quercus infectoria L., Pinus nigra Arn. ssp. pallasiana (Lamb) Holmboe. trees have been used with the aim of determining how far the gas and particles emitted from the TPP are carried, and for assessment of environmental impact. The results obtained from locations chosen at various distances to the TPP, indicate that the contaminating agents are very dense and effective; particularly in the prevailing wind direction and within 10 km of the plant. They gradually lose their density and effect beyond this distance. The sulfur and heavy metal analyses made in soils taken from these locations indicate a similarity with the data obtained from the leaves. PMID:15488593

  18. Measurement of tritiated water transpiration from tree leaves following root injection

    International Nuclear Information System (INIS)

    The Sydney Water Board were looking for a means of assessing the efficacy and practicality of using tritiated water (HTO) for the treatment of sewer systems infested by tree roots. After discussion, it was agreed that ANSTO would assess the use of tritiated water as a means of determining the water transport function in roots. The proposed method of assessment is based upon measuring the rate at which tritiated water is moved away from the root infesting the sewer by the normal transpiration stream. The method assumes that the treatment applied to the sewer drastically reduces, if not destroys, root function. This should be reflected in a significant increase in the delay of HTO arrival at the leaves following application to the affected root. Any significant flux from the affected root would indicate inadequate treatment as water flow from the affected root would encourage subsequent re-invasion of the sewer. If deemed suitable, this tracer would in turn be used to determine the efficacy of the treatment in inhibiting root function. Constraints on the study as well as the optimal conditions for using HTO are discussed. The method which involves injection of tritium into the xylem tissue of the tree followed by collection of transpirate to observe the pattern of tritium arrival, is amenable to the task of assessing the efficiency of the treatment process if the site of infestation can be excavate without damage to the roots and if HDO can be injected and sealed with a root of adequate dimensions. 2 refs., 1 tab., 7 figs

  19. Statistical topology of radial networks: a case study of tree leaves

    Science.gov (United States)

    Seong, Rak-Kyeong; Salafia, Carolyn M.; Vvedensky, Dimitri D.

    2012-01-01

    We describe a statistical method for characterizing the topological properties of radial networks based on the distribution of their 'energy' states, which are determined from the structural triangulation of the network. The partition function obtained from these energy states is used to calculate thermodynamic functions that embody the statistical properties of the network. The entropy, in particular, is a measure of the distribution of triangulated areas in the network, with a larger entropy corresponding to a higher symmetry in the branching structure. By varying the distribution parameter, which corresponds to an inverse 'temperature' in the statistical thermodynamic interpretation, we are able to vary the weight of the different generations of the network. This analysis identifies similar networks at their maturation state - the state when the system stops growing - as well as enabling the development of a network to be investigated. The latter feature is especially important for biological systems, where the details of the expansion of the network are not typically available. We illustrate our methodology with a model for the optimal transport of nutrients within tree leaves and show that statistical thermodynamic functions are capable of discriminating between various types of such radial networks. We conclude with a discussion about applications to the vasculature of the human placenta, which is our main motivation in developing this approach.

  20. Effect of the extraction process on yield and composition of selected extracts from maidenhair tree green and yellow leaves

    OpenAIRE

    Joanna Kobus-Cisowska; Ewa Flaczyk; Aleksander Siger; Dominik Kmiecik

    2015-01-01

    The aim of the study was to evaluate the effect of extraction process on the extraction efficiency and composition of selected extracts from the maidenhair tree (Ginkgo biloba L.) green and yellow leaves. Taken three-step extraction, where water, solution of acetone and water and ethyl alcohol were used, effectiveness by evaluating the content of total polyphenols was estimated. In the next step yield of selected extraction processes was estimated, then UV spectra of the obtained extracts and...

  1. Optimization and characterization of Tl(I) adsorption onto modified ulmus carpinifolia tree leaves

    Energy Technology Data Exchange (ETDEWEB)

    Zolgharnein, Javad; Asanjarani, Neda [Faculty of Science, Department of Chemistry, Arak University, Arak (Iran, Islamic Republic of); Mousavi, S. Norollah [Faculty of Science, Department of Mathematics, Arak University, Arak (Iran, Islamic Republic of)

    2011-03-15

    Ulmus carpinifolia tree leaves were successfully used to remove Tl(I) from aqueous solution in a batch system. In order to improve the uptake capacity of sorbent, it was modified by various chemical agents such as NaOH, HNO{sub 3}, NH{sub 3}, NaCl, NaHCO{sub 3}, and CaCl{sub 2}. Among the modifiers, NaCl was the best. Equilibrium behavior of sorbent with Tl(I) was examined by the several isotherms. Considering modified U. carpinifolia equilibrium data fitted well to the Langmuir model with maximum capacity of 54.6 mg/g. The other isotherms such as: Freundlich and Dubinin-Redushkevich (D-R) models were also examined. The central composite design (CCD) was successfully employed for optimization of biosorption process. An empirical model was given through using response surface methodology. Also its validation was recognized by using relevant statistical tests such as ANOVA. The optimum conditions of biosorption: pH, m (amount of sorbent) and C (initial concentration) were found to be 7.9, 11.4 g/L, and 8.8 mg/L, respectively. On the other hand thermodynamic parameters: {Delta}G, {Delta}H, and {Delta}S were evaluated: the obtained results show that biosorption process was spontaneous and exothermic. Eventually, FT-IR analysis confirmed that the main functional groups of sorbent have been involved through the biosorption process. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Determination of rare earth elements in dust deposited on tree leaves from Greater Cairo using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    This work aims at monitoring the rare earth elements (REEs) and Th in dust deposited on tree leaves collected inside and outside Greater Cairo (GC), Egypt. Inductively coupled plasma mass spectrometry (ICP-MS) was employed. The concentration of REEs in the collected dust samples was found to be in the range from 1 to 60 μg g−1. The highest concentration of REEs was found in dust samples collected outside GC, in the middle of the Nile Delta. This would refer to the availability of black sands, due to desert wind occurrence during the sample collection, and anthropogenic activities. The limits of detection of the REEs ranged from 0.02 ng g−1 for Tm to 3 ng g−1 for Yb. There was an obvious variation in the concentration of REEs inside and outside GC due to variations of natural and anthropogenic sources. Strong correlations among all the REEs were found. -- Highlights: •Rare earth elements (REEs) were determined in dust samples using ICP-MS. •The dusts were deposited on tree leaves and were collected at 19 sites. •REE concentrations were in the range from 1 to 60 μg g−1. •High concentration of REEs was found in the middle of Nile Delta. -- For the first time, rare earth elements (REEs) and Th were determined in dust deposited on tree leaves collected at 19 sites in the Greater Cairo

  3. Stem water storage in five coexisting temperate broad-leaved tree species: significance, temporal dynamics and dependence on tree functional traits.

    Science.gov (United States)

    Köcher, Paul; Horna, Viviana; Leuschner, Christoph

    2013-08-01

    The functional role of internal water storage is increasingly well understood in tropical trees and conifers, while temperate broad-leaved trees have only rarely been studied. We examined the magnitude and dynamics of the use of stem water reserves for transpiration in five coexisting temperate broad-leaved trees with largely different morphology and physiology (genera Fagus, Fraxinus, Tilia, Carpinus and Acer). We expected that differences in water storage patterns would mostly reflect species differences in wood anatomy (ring vs. diffuse-porous) and wood density. Sap flux density was recorded synchronously at five positions along the root-to-branch flow path of mature trees (roots, three stem positions and branches) with high temporal resolution (2 min) and related to stem radius changes recorded with electronic point dendrometers. The daily amount of stored stem water withdrawn for transpiration was estimated by comparing the integrated flow at stem base and stem top. The temporal coincidence of flows at different positions and apparent time lags were examined by cross-correlation analysis. Our results confirm that internal water stores play an important role in the four diffuse-porous species with estimated 5-12 kg day(-1) being withdrawn on average in 25-28 m tall trees representing 10-22% of daily transpiration; in contrast, only 0.5-2.0 kg day(-1) was withdrawn in ring-porous Fraxinus. Wood density had a large influence on storage; sapwood area (diffuse- vs. ring-porous) may be another influential factor but its effect was not significant. Across the five species, the length of the time lag in flow at stem top and stem base was positively related to the size of stem storage. The stem stores were mostly exhausted when the soil matrix potential dropped below -0.1 MPa and daily mean vapor pressure deficit exceeded 3-5 hPa. We conclude that stem storage is an important factor improving the water balance of diffuse-porous temperate broad-leaved trees in moist

  4. Leaves of Field-Grown Mastic Trees Suffer Oxidative Stress at the Two Extremes of their Lifespan

    Institute of Scientific and Technical Information of China (English)

    Marta Juvany; Maren Müller; Sergi Munné-Bosch

    2012-01-01

    Leaf senescence is a complex phenomenon occurring in all plant species,but it is still poorly understood in plants grown in Mediterranean field conditions and well-adapted to harsh climatic conditions.To better understand the physiological processes underlying leaf senescence in mastic trees (Pistacia lentiscus L.),we evaluated leaf growth,water and N content,photosystem Ⅱ (PSⅡ) photochemistry,lipid peroxidation and levels of photosynthetic pigments,antioxidants,abscisic acid,and salicylic acid and jasmonic acid during the complete leaf lifespan,from early expansion to late senescence in relation to natural climatic conditions in the field.While mature leaves suffered from water and N deficit during late spring and summer,both young (emerging) and old (senescing) leaves were most sensitive to photooxidative stress,as indicated by reductions in the Fv/Fm ratio and enhanced lipid peroxidation during late autumn and winter.Reductions in the Fv/Fm ratio were associated with low α-tocopherol (vitamin E) levels,while very old,senescing leaves additionally showed severe anthocyanin losses.We have concluded that both young (emerging) and old (senescing) leaves suffer oxidative stress in mastic trees,which may be linked in part to suboptimal temperatures during late autumn and winter as well as to low vitamin E levels.

  5. Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

    Science.gov (United States)

    We investigated the effects of nitrogen (N) availability and spraying trees with urea, copper chelate (CuEDTA), and phosphonate-containing fungicides on tree N status and susceptibility to infection by Phytophthora syringae. Increasing soil N availability increased susceptibility and increased N and...

  6. Effect of the extraction process on yield and composition of selected extracts from maidenhair tree green and yellow leaves

    Directory of Open Access Journals (Sweden)

    Joanna Kobus-Cisowska

    2015-03-01

    Full Text Available The aim of the study was to evaluate the effect of extraction process on the extraction efficiency and composition of selected extracts from the maidenhair tree (Ginkgo biloba L. green and yellow leaves. Taken three-step extraction, where water, solution of acetone and water and ethyl alcohol were used, effectiveness by evaluating the content of total polyphenols was estimated. In the next step yield of selected extraction processes was estimated, then UV spectra of the obtained extracts and their content of phenolic acids. The content of phenolic compounds in the following extracts showed high efficiency of the first extraction process. Analysis of UV spectra allowed to deduce the presence of phenolic compounds in all tested extracts. The absorption maxima were recorded at wavelengths between 290 nm and 350 nm. Analysed extracts showed high content of phenolic acids. The largest of the sum of phenolic acids was estimated in the acetone-water extract from green leaves and in water extract from yellow leaves. In green leaves extracts the predominant acid was protocatechuic, while in yellow leaves extracts the greatest amount of p-hydroxybenzoic acid was shown.

  7. Quantitative analysis of arbutin and hydroquinone in strawberry tree (Arbutus unedo L., Ericaceae) leaves by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Jurica, Karlo; Karačonji, Irena Brčić; Šegan, Sandra; Opsenica, Dušanka Milojković; Kremer, Dario

    2015-09-01

    The phenolic glycoside arbutin and its metabolite with uroantiseptic activity hydroquinone occur naturally in the leaves of various medicinal plants and spices. In this study, an extraction procedure coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine arbutin and hydroquinone content in strawberry tree (Arbutus unedo L., Ericaceae) leaves. The method showed good linearity (R2>0.9987) in the tested concentration range (0.5-200 μg mL(-1)), as well as good precision (RSDarbutin and hydroquinone, respectively). The results obtained by the validated GC-MS method corresponded well to those obtained by high performance liquid chromatography (HPLC) method. The proposed method was then applied for determining arbutin and hydroquinone content in methanolic leaf extracts. The amount of arbutin in the leaves collected on the island of Koločep (6.82 mg g(-1) dry weight) was found to be higher (tpaired=43.57, tc=2.92) in comparison to the amount of arbutin in the leaves collected on the island of Mali Lošinj (2.75 mg g(-1) dry weight). Hydroquinone was not detected in any of the samples. The analytical features of the proposed GC-MS method demonstrated that arbutin and hydroquinone could be determined alternatively by gas chromatography. Due to its wide concentration range, the method could also be suitable for arbutin and hydroquinone analysis in leaves of other plant families (Rosaceae, Lamiaceae, etc.). PMID:26444340

  8. Accuracy of LiDAR-based tree height estimation and crown recognition in a subtropical evergreen broad-leaved forest in Okinawa, Japan

    OpenAIRE

    Azita Ahmad Zawawi; Masami Shiba; Noor Janatun Naim Jemali

    2015-01-01

    Aim of study: To present an approach for estimating tree heights, stand density and crown patches using LiDAR data in a subtropical broad-leaved forest. Area of study: The study was conducted within the Yambaru subtropical evergreen broad-leaved forest, Okinawa main island, Japan. Materials and methods: A digital canopy height model (CHM) was extracted from the LiDAR data for tree height estimation and a watershed segmentation method was applied for the individual crown delineation....

  9. Correlation between air pollution and crystal pattern of calcium oxalate in plant leaves of street trees in Itami City. [Ginkgo biloba; Salix babylonica; Aphananthe aspera; Robinia pseudoacacia

    Energy Technology Data Exchange (ETDEWEB)

    Umemoto, K.; Tatsumi, S.

    1975-01-01

    A characteristic difference in calcium oxalate crystal patterns in leaves of roadside trees planted in relatively unpolluted northern parts of Itami City and in parts of the city polluted by automobile exhaust was discovered. The species of trees examined were Ginkgo biloba, Salix babylonica, Aphananthe aspera, Robinia pseudoacacia, and Poplar. The leaves of trees grown in relatively less air polluted areas displayed crystal aggregates of calcium oxalate (50-80 micron) that were arranged in rows on both sides of the central vein; some scattered crystal aggregates between veins were observed. Trees grown in air polluted areas showed irregular crystal patterns and more scattering of the crystals between veins. The cause of the observed differences in the pattern of crystal aggregates was attributed to the difference in metabolism of trees under different environmental conditions. Air pollutants disturb the normal metabolism of the tree and cause hyperproduction of calcium oxalate.

  10. IN VITRO RUMINAL PROTEIN DEGRADABILITY OF LEAVES FROM THREE TREE SPECIES HARVESTED AT TWO CUTTING INTERVALS

    Directory of Open Access Journals (Sweden)

    A. EDWARDS

    2012-05-01

    Full Text Available In vitro ruminal protein degradation characteristics of protein supplements represent an accurate measure of the quality of protein for ruminant animals. As such, crude protein disappearance of Gliricidia sepium, Leucaena leucocephala and Trichanthera gigantea leaves, which are potential sources of supplemental protein for ruminants, was determined using the ANKOM in vitro ruminal degradability technique. Dry matter (DM and crude protein (CP disappearance were measured after 0, 2, 4, 6, 12, 24, 36, 48 and 72 h of incubation. Degradation kinetics were described using the Ørskov and McDonald equation  cx  y a b e   1 . The degradable part of the insoluble DM fraction (b was highest (P<0.05 in G. sepium leaves (27% at the 12 week cutting interval. Effective dry matter degradability (EDMD was highest (P < 0.05 in the leaves of G. sepium (74.9% at the 12-week cutting interval. CP washing losses was highest (P < 0.05 in the leaves of L. leucocephala (46.8% and lowest in T. gigantea leaves (16.3% at the 6-week cutting interval. Crude protein disappearance was highest (P<0.05 in the leaves of G. sepium and lowest in T. gigantea leaves at both the 6 and 12-week cutting intervals after incubation at 48 h. It is concluded that in vitro ruminal protein degradability is more pronounced in the leaves of G. sepium and L. leucocephala. Approximately 50% of their protein is degraded in the rumen suggesting that they would be useful as sources of readily available nitrogen for rumen microbes challenged with low nitrogen, fibrous basal diets. Trichanthera gigantea leaves have higher levels of rumen undegradable protein suggesting that they can be used to supply by-pass protein for animal.

  11. Occurrence of tannins in leaves of beech trees (Fagus sylvatica) along an ecological gradient, detected by histochemical and ultrastructural analyses

    International Nuclear Information System (INIS)

    Sclerophylly and synthesis of phenolic compounds are active responses of plants subjected to environmental stress (drought, low nutrient supply, u.v.-B radiation, ozone). Here we describe the morphological and histochemical alterations occurring in field-grown leaves of Fagus sylvatica L. from three sites located along an ecological gradient: from a site in cool and protected conditions to one located on a mountain ridge, where the trees grow on a thin layer of soil and are exposed to the wind and to intense solar radiation in summer. The morphological data show that, as the ecological conditions of the stand worsen, individual leaf surface decreases, while the thickness of the leaves and their specific d. wt (i.e. d. wt per unit leaf area) increases. Histochemical and ultrastructural tests show a marked increase of phenolics during the course of the year. These substances, present primarily in the leaves of trees growing in stress conditions, have been identified mainly as tannins. They accumulate in the vacuoles, especially those of the upper epidermal layer and the palisade mesophyll; at a later stage they appear to be solubilized in the cytoplasm and retranslocated, eventually impregnating the outer wall of the epidermal cells amidst the cellulose fibrils, where they cluster together and form an electron-opaque layer between the wall and the cuticle. Observation of the epidermal cells also reveals that the outer cell wall is thicker. The paper discusses the roles of secondary metabolites in protection and detoxification processes; the possible ecological significance of these alterations in the ecophysiology of beech trees. (author)

  12. Ecophysiological and seasonal variations in Cd, Pb, Zn, and Ni concentrations in the leaves of urban deciduous trees in Istanbul

    International Nuclear Information System (INIS)

    The concentrations of Cd, Pb, Zn and Ni were measured in the leaves of 7 species of deciduous trees, from the urban sites of Istanbul, in both the Spring and Autumn seasons. We detected some differences in the heavy metal concentrations of the control and urban site samples of identical species. Highest concentrations of Cd were detected in Populus, Pb in Aesculus and Robinia, Zn in Populus, and Ni in Robinia and Fraxinus. Lowest chlorophyll content and highest peroxidase (POD) activity was found in the urban site samples of Acer. We have found a positive correlation between the increase in the POD activity and the Pb concentration in Populus. Generally, the tree species investigated in this study, are considered to have different tolerance levels to heavy metal pollution. The data obtained show that the chlorophyll content and the POD activity may be used as heavy metal stress biomarkers in the urban trees. - Ecophysiological changes in the urban trees may be used as heavy metal stress biomarkers

  13. Changes in laser induced fluorescence and sugar content of tree leaves with dark treatment

    International Nuclear Information System (INIS)

    Efficient tree diagnosis methods have been required for the improvement of maintenance techniques in indoor plants. Laser induced chlorophyll fluorescence induction kinetics have been shown to be one of the possible techniques to detect indoor tree conditions. In this study, changes in induction kinetics and leaf sugar content with the dark treatment were investigated using Myrica rubra and Ternstroemia gymnanthera. Measurements conducted during July and September (Japan) showed good correlation between the period of dark treatment and the induction kinetics/leaf sugar content, regardless of the kind of trees tested. Effects of the dark treatment were detected in the second time derivatives of the induction kinetics curves between 5-24s. However, results in the early spring and late fall did not show such correlation. These results showed that LIF application to detect low irradiance stress of indoor plants has high potential, but that its application season is restricted

  14. Effect of the air pollution by heavy metals in the tree leaves in the metropolitan area of Toluca Valley

    International Nuclear Information System (INIS)

    Leaves of two tree species: Juniperus sp and Ligustrum sp were studied as indicators of pollution heavy metals (Mn, Fe, Cu, Zn and Pb) in the atmosphere of the Metropolitan Area of the Toluca Valley. Bio markers of catalase, superoxide dismutase, ascorbate peroxidase, guaiacol, proteins and pigments were measured in order to determine the effects to atmospheric stress caused by heave metals during two periods in the year (December 2012 and May 2013). Metals were quantified in dry deposit and tissue on trees tissue leaves using the technique of Energy Dispersive X-ray Fluorescence Spectroscopy and Total Reflection X-ray Fluorescence Spectroscopy respectively. The results show greater response of enzyme inhibition in Juniperus sp. species, with decreased protein content and increased lipid peroxidation at sites with higher content of metals in tissue belonging to urban areas with increased industrial activity and traffic flow. In dry deposit bioavailability factor of metals was Fe>Mn> Zn> Cu>Pb for the first time of sampling and Fe>Mn> Cu> Zn>Pb for the second sampling period. (Author)

  15. Biomimicry of Palm Tree Leaves Form and Pattern on Building Form

    Directory of Open Access Journals (Sweden)

    Agus Salim N.A.

    2014-01-01

    Full Text Available This article is a study on biomimicry of palm tree towards a building form. It is to find a suitable form and pattern that can be applied to building shell to ease building maintenance operation beside to enhance the aesthetic value of a building architecture. The research has been carried out by observation and modeling on some various species of palm tree’s patterns and forms. The result expectation can be found at the end of this research by producing the best pattern of palm tree that can be adapted to building envelop as the whole form of a building.

  16. Biomimicry of Palm Tree Leaves Form and Pattern on Building Form

    OpenAIRE

    Agus Salim N.A.; Mydin M.A.O; Ulang N. H. Md.

    2014-01-01

    This article is a study on biomimicry of palm tree towards a building form. It is to find a suitable form and pattern that can be applied to building shell to ease building maintenance operation beside to enhance the aesthetic value of a building architecture. The research has been carried out by observation and modeling on some various species of palm tree’s patterns and forms. The result expectation can be found at the end of this research by producing the best pattern of palm tree that can...

  17. Urban deciduous tree leaves as biomonitors of trace element (As, V and Cd atmospheric pollution in Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    KATARINA M. ŠUĆUR

    2010-10-01

    Full Text Available Leaves of common deciduous trees: horse chestnut (Aesculus hippocastanum and linden (Tilia spp. from three parks within the urban area of Belgrade were studied as biomonitors of trace element (As, V, and Cd atmospheric pollution. The May–September trace element accumulation in the leaves, and their temporal trends, were assayed in a multi-year period (2002–2006. Significant accumulation in the leaves was evident for As and V, but not so regularly for Cd. Slightly decreasing temporal trends of V and As ac-cumulated in the leaf tissues were observed over the years. During the time span, the concentrations of Cd remained approximately on the same level, except in May 2002 and September 2005, when a rapid increase was observed. The May–September accumulations of As and V were higher in horse chestnut than in linden, although both may be used as biomonitors for these elements, and optionally for Cd in conditions of its high atmospheric loadings.

  18. Olive Tree (Olea europeae L.) Leaves: Importance and Advances in the Analysis of Phenolic Compounds

    OpenAIRE

    Leila Abaza; Amani Taamalli; Houda Nsir; Mokhtar Zarrouk

    2015-01-01

    Phenolic compounds are becoming increasingly popular because of their potential role in contributing to human health. Experimental evidence obtained from human and animal studies demonstrate that phenolic compounds from Olea europaea leaves have biological activities which may be important in the reduction in risk and severity of certain chronic diseases. Therefore, an accurate profiling of phenolics is a crucial issue. In this article, we present a review work on current treatment and analyt...

  19. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES.

    Science.gov (United States)

    Zeng, Jianrong; Zhang, Guilin; Bao, Liangman; Long, Shilei; Tan, Mingguang; Li, Yan; Ma, Chenyan; Zhao, Yidong

    2013-03-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmental biology. A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy was established to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs), which were sampled from 5 local fields in Shanghai, China. Annual SO2 concentration, SO4(2-) concentration in atmospheric particulate, SO4(2-) and sulfur concentration in soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs. Total sulfur concentration in mature camphor tree leaves was 766-1704 mg/kg. The mainly detected sulfur states and their corresponding compounds were +6 (sulfate, include inorganic sulfate and organic sulfate), +5.2 (sulfonate), +2.2 (suloxides), +0.6 (thiols and thiothers), +0.2 (organic sulfides). Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlation coefficient up to 0.977, which suggested that sulfur accumulated in CTLs as sulfate form. Reduced sulfur compounds (organic sulfides, thiols, thioethers, sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced level around 526 mg/kg. The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulate instead of soil contamination. From urban to suburb place, sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced, but a dramatic increase presented near the seashore, where the marine sulfate emission and maritime activity pollution were significant. The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmospheric sulfur pollution in local environment. PMID:23923435

  20. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

    Institute of Scientific and Technical Information of China (English)

    Jianrong Zeng; Guilin Zhang; Liangman Bao; Shilei Long; Mingguang Tan; Yan Li; Chenyan Ma

    2013-01-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmentalbiology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy wasestablished to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 localfields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentrationin soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Totalsulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their correspondingcompounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols andthiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlationcoefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced levelaround 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulateinstead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmosphericsulfur pollution in local environment.

  1. Assessment of the urban trees health status on the base of nutrient and pigment content in their leaves

    Directory of Open Access Journals (Sweden)

    SLAVEYA PETROVA

    2014-04-01

    Full Text Available Town settlements have different load level by emissions originated mostly from transport, industry and heating system. Their environmental and climate conditions are more or less changed that effect to growth, physiology and vigor of woody plants at the city public vegetation areas. Our study on determining the impact of urban environment on the tree health status was focused on the quantities of nutrients and main components of the pigment complex – chlorophyll a, chlorophyll b and carotenoids. Leaves of Acer platanoides L., Aesculus hippocastanum L. and Betula pendula Roth. were sampled from urban areas with different type of anthropogenic pressure in the town of Plovdiv (Bulgaria. Concentrations of the elements Ca, K, Mg, N, Na, P, and S were analyzed by ICP-MS. Health condition of trees in the city parks and suburban areas was acceptable, but in the central part and close to the industrial area it was non-satisfactory. This preliminary research pointed ecophysiological tools as useful to develop new criteria for sustainable urban arboriculture, including species selection (based on stress tolerance criteria, nursery hardening and preconditioning, and care after planting.

  2. Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

    Directory of Open Access Journals (Sweden)

    Leandro Fabrício Fiori

    2015-09-01

    Full Text Available Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet. The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl. Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

  3. Lead and cadmium in leaves of deciduous trees in Beijing, China: Development of a metal accumulation index (MAI)

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yanju [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China) and Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: liuyanju@hotmail.com; Zhu Yongguan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Ding Hui [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China)

    2007-01-15

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. - Catalpa speciosa had the highest MAI value.

  4. Isolation, Structural Characterization, and Valorization of Pectic Substances from Algerian Argan Tree Leaves (Argania spinosa (L. Skeels

    Directory of Open Access Journals (Sweden)

    Kadda Hachem

    2015-01-01

    Full Text Available Pectic polysaccharides were solubilized from Algerian argan tree leaves by sequential extraction with water at 100°C (water-soluble pectin; AL-WSP and EDTA solution at 80°C (chelating-soluble pectin; AL-CSP. Both AL-WSP and AL-CSP were rich in arabinose (28% and 74.5%, resp. and had a high content of uronic acid (38.5% and 21.5%, resp.. Pectic substances were deesterified and fractionated by anion exchange chromatography, giving five fractions for each extract. Most of the fractions were characterized by methylation analysis and then analyzed by 13C nuclear magnetic resonance spectroscopy. The results showed that AL-WSP consisted of rhamnogalacturonan type I, with arabinan and galactan branching at the O-4 position of the main rhamnose chain, while AL-CSP consisted of rhamnogalacturonan type I and a block of homogalacturonan. Antioxidant activities of AL-WSP and AL-CSP were evaluated by electronic spin resonance. The results showed that the antioxidant potential of AL-WSP (8.1% and AL-CSP (−1.2% was significantly lower than that of vitamin E.

  5. Lead and cadmium in leaves of deciduous trees in Beijing, China: development of a metal accumulation index (MAI).

    Science.gov (United States)

    Liu, Yan-Ju; Zhu, Yong-Guan; Ding, Hui

    2007-01-01

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. PMID:16797111

  6. Lead and cadmium in leaves of deciduous trees in Beijing, China: Development of a metal accumulation index (MAI)

    International Nuclear Information System (INIS)

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. - Catalpa speciosa had the highest MAI value

  7. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    Science.gov (United States)

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  8. Autoencoder Trees

    OpenAIRE

    İrsoy, Ozan; Alpaydın, Ethem

    2014-01-01

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

  9. Determination of mass attenuation coefficient in wood and leaves of typical trees by gamma-ray attenuation technique

    International Nuclear Information System (INIS)

    Using an 241 Am source the mass attenuation coefficient of different woods and leaves of typical species of the Atlantic Forest were measured. The results for natural wood, dry wood and dry leaves indicate that the variation is very small among different species. However, woods present a higher attenuation than leaves, both depending on their water content. (author). 10 refs., 3 figs., 1 tab

  10. Wybrane zagadnienia z morfogenezy liści drzew. II. Występowanie młodocianych form liści w koronach drzew buka zwyczajnego (Fagus silvatica L. [Studies on the mohprogenesis of tree-leaves. II. The occurrence of juvenile forms of leaves in the crowns of beech trees (Fagus silvatica L.

    Directory of Open Access Journals (Sweden)

    I. Więckowska

    2015-05-01

    Full Text Available It was fairly often observed that Fagus silvatica L. leafed twice during one vegetational season. This secondary growth occurred on all trees, when the first leaves underwent destruction, e.g. in consequence of late spring frost. The leaves of secondary growth differed pronouncedly from normally developed ones by their shape and irregular nervation and were similar to the juvenile leaves of one-year-old seedlings of beech. Observations of leaf buds showed that the nerves appeared in leaf-primordia of Fagus silvatica as late as the latter part of July and if the secondary leaves developed at the end of July, they were normal in shape and bad regular nervation. Leaf-primordia compelled to an earlier development gave leaves of different form and irregular nervation.

  11. Trees

    CERN Document Server

    Epstein, Henri

    2016-01-01

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

  12. ACCLIMATION OF PHOTOSYNTHESIS IN LEAVES OF SOUR ORANGE TREES GROWN AT ELEVATED CO2 FOR 14 YEARS.

    Science.gov (United States)

    Perennial trees are a major carbon sink on a global scale, accounting for approximately two-thirds of terrestrial carbon fixation. Understanding how slow-growing perennial trees will be affected by future increasing levels of carbon dioxide after a period of years or decades is crucial to understan...

  13. aLeaves facilitates on-demand exploration of metazoan gene family trees on MAFFT sequence alignment server with enhanced interactivity.

    Science.gov (United States)

    Kuraku, Shigehiro; Zmasek, Christian M; Nishimura, Osamu; Katoh, Kazutaka

    2013-07-01

    We report a new web server, aLeaves (http://aleaves.cdb.riken.jp/), for homologue collection from diverse animal genomes. In molecular comparative studies involving multiple species, orthology identification is the basis on which most subsequent biological analyses rely. It can be achieved most accurately by explicit phylogenetic inference. More and more species are subjected to large-scale sequencing, but the resultant resources are scattered in independent project-based, and multi-species, but separate, web sites. This complicates data access and is becoming a serious barrier to the comprehensiveness of molecular phylogenetic analysis. aLeaves, launched to overcome this difficulty, collects sequences similar to an input query sequence from various data sources. The collected sequences can be passed on to the MAFFT sequence alignment server (http://mafft.cbrc.jp/alignment/server/), which has been significantly improved in interactivity. This update enables to switch between (i) sequence selection using the Archaeopteryx tree viewer, (ii) multiple sequence alignment and (iii) tree inference. This can be performed as a loop until one reaches a sensible data set, which minimizes redundancy for better visibility and handling in phylogenetic inference while covering relevant taxa. The work flow achieved by the seamless link between aLeaves and MAFFT provides a convenient online platform to address various questions in zoology and evolutionary biology. PMID:23677614

  14. Carbonic anhydrase activity and photosynthetic rate in the tree species Paulownia tomentosa Steud. Effect of dimethylsulfoxide treatment and zinc accumulation in leaves.

    Science.gov (United States)

    Lazova, Galia N; Naidenova, Tsveta; Velinova, Katya

    2004-03-01

    The enzyme carbonic anhydrase (CA) (EC 4.2.1.1) catalyzes the reversible conversion of CO2 to HCO3- and has been shown to be involved in photosynthesis. The enzyme has been shown in animals, plants, eubacteria and viruses, but similar reports on the evidence for CA activity in tree plants does not be appear to be available. In the preliminary analyses of the work, the CA activity in leaf extracts from the tree species Paulownia tomentosa Steud. (introduced in Bulgaria) is described. A connection between CA activity and the rate of photosynthetic CO2 fixation is shown. In the second portion of the work, the effect of 10(-4) mol/L and 10(-2) mol/L dimethylsulfoxide (DMSO) on the zinc accumulation in leaves is demonstrated. It is suggested that CA activity is an indicator of the level of physiologically active zinc in leaves of P. tomentosa Steud. A connection between the process of zinc accumulation in leaves and the activity of the enzymes CA and glycolate oxidase (GO) (EC 1.1.3.1) is established. PMID:15077628

  15. Nitrogen storage and distribution and reuse of 15N-urea applied in autumn on different branch leaves of winter Jujube (Zizyphus jujuba Mill. var. inermis Rehd) trees

    International Nuclear Information System (INIS)

    The effectiveness of foliage spraying with urea to augment the seasonal internal cycling of N in winter Jujube was studied. Different branches leaves of 6-year-old trees were painted with 5% abundance of 15N-urea solution after fruit harvesting. Results showed that 15N was detected in all the tree organs during the dormant season. In the following year 15N was also detected in new growth organs (deciduous spurs, leaves and flowers). The treated branches and adjacent organs were the main sinks of Nitrogen in the dormant season. Ndff% in the treated branches was significantly decreased during dormant season. And a decrease of 59.13% was observed in the new growth branch treated and 60.05% in the perennial branches. Reserved nitrogen was reused for initial growth (leaves and deciduous spurs). 15N stored in perennial organs also remobilized to sustain new growth of treated branches. It is different from the treated new growth branch, 15N stored in the treated perennial branches is not only transported for new organs growth, but also for roots growth. (authors)

  16. Differences in secondary metabolites in leaves from orange trees (Citrus sinensis L.) affected with greening disease (Huanglongbing) (HLB)

    Science.gov (United States)

    Preliminary analyses by HPLC-MS of methanolic extracts of two sets of orange leaves that are symptomatic of the Greening Disease (HLB) have shown several consistent differences. The main flavonoids in symptomatic and nonsymptomatic leaves were monitored in the HPLC chromatograms at 330 nm, and signi...

  17. Synthesis, Characterization, and Catalytic Activity of Sulfonated Carbon-Based Catalysts Derived From Rubber Tree Leaves and Pulp and Paper Mill Waste

    Science.gov (United States)

    Janaun, J.; Sinin, E.; Hiew, S. F.; Kong, A. M. T.; Lahin, F. A.

    2016-06-01

    Sulfonated carbon-based catalysts derived from rubber tree leaves, and pulp and paper mill waste were synthesized and characterized. Three types of catalyst synthesized were sulfonated rubber tree leaves (S-RTL), pyrolysed sludge char (P-SC) and sulfonated sludge char (S-SC). Sulfonated rubber tree leaves (S-RTL) and sulfonated sludge char (S-SC) were prepared through pyrolysis followed by functionalization via sulfonation process whereas, P- SC was only pyrolyzed without sulfonation. The characterization results indicated sulfonic acids, hydroxyl, and carboxyl moieties were detected in S-RTL and S-SC, but no sulfonic acid was detected in P-SC. Total acidity test showed S-RTL had the highest value followed by S-SC and P-SC. The thermal stability of S-RTL and S-SC were up to 230oC as the loss was associated with the decomposition of sulfonic acid group, whereas, P-SC showed higher stability than the S-RTL and S-SC. Morphology analysis showed that S-RTL consisted of an amorphous carbon structure, and a crystalline structure for P-SC and S-SC. Furthermore, traces of metal components were also detected on all of the catalysts. The catalyst catalytic activity was tested through esterification of oleic acid with methanol. The results showed that the reaction using S-RTL catalyst produced the highest conversion (99.9%) followed by P-SC (88.4%) and lastly S-SC (82.7%). The synthesized catalysts showed high potential to be used in biodiesel production.

  18. Spatial distribution of anthropogoenic pollution acumulated on tree leaves, soil and street dust in the park area in the centre of Warsaw

    Science.gov (United States)

    Dytłow, Sylwia; Górka-Kostrubiec, Beata

    2015-04-01

    The magnetic method has been successfully used to evaluate and characterise the degree of air pollution. This method is based on investigation of properties of magnetic particles of pollution such as magnetic susceptibility, parameters of hysteresis loops and temperature-dependence of magnetic parameters etc. The motivation to undertake this study was to find the distribution of pollution emitted by traffic vehicles in a green area situated in urban environment. The investigated area is the oldest public park named Saxon Garden in the centre of Warsaw, Poland. The Saxon Garden is located between the very busy main road with tram line, two local streets (low traffic volume) and big plaza without car traffic and trees. In order to quantify the degree of pollution we measured magnetic susceptibility of pollution deposited on chestnut leaves (the most abundant tree species in the park), surface of the roads (street dust) and in soil from the park area. The highest values of magnetic susceptibility of pollution were observed on tree leaves located along the edges/borders of park area (190 [m3/kg]), directly adjacent to busy roads. The lowest values of magnetic susceptibility (20 [m3/kg]) were obtained for leave samples from the borders of park, directly adjacent to plaza and roads with low traffic volume. It was observed that the intensity of magnetic susceptibility decreases with the distance of pollution source i.e. main streets. A similar distribution of intensity of magnetic susceptibility was observed for the soil samples collected from park area. With the exception of a few samples, the magnetic susceptibility of soil samples were higher than for leave samples. Our study showed that the distribution of magnetic susceptibility of soil and leave samples correlate with the intensity of magnetic susceptibility of street dust taken from the road surfaces situated along the boundary of the park area. On the basis of the detailed research of the domain structure and

  19. Environmental Correlates of Distribution of the 25 Broad-leaved Tree Species Indigenous to Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    Su Zhiyao; Chen Beiguang; Chang Yong; Yang Jiazhi

    2004-01-01

    Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental factors were tabulated based on a digitized map of Guangdong Province gridded at 0.5° latitude × 0.5° longitude. Grid-based diversity was mapped using DMAP, a distribution mapping program, and horizontal patterns were assessed using Kruskal-Wallis tests. The diversity center of the indigenous tree species under study is located north of 23° N. These tree species exhibit significant latitudinal variation (P = 0.007 4), but no significant longitudinal difference (P = 0.052 2). Non-metric Multidimensional Scaling (NMS) identified five different ecological species groups, while Canonical Correspondence Analysis (CCA) showed the distribution of tree species along each of the five environmental gradients. An understanding of the environmental correlates of distribution patterns has great implication for the introduction of the indigenous tree species for afforestation.

  20. DIVERSITY AND ECOLOGICAL DETERMINANTS OF DEAD WOOD FUNGI IN TREE NATURAL RESERVES OF BROAD LEAVED FORESTS FROM SUCEAVA COUNTY

    Directory of Open Access Journals (Sweden)

    Ciprian BÎRSAN

    2014-12-01

    Full Text Available Dead wood fungi have a major importance for forests biodiversity as they produce wood degradation in forest habitats. In this paper are presented some aspects related to the diversity of dead wood fungi in tree deciduous forest types from tree natural reserves (Crujana, Dragomirna and Zamostea from Suceava County and the effect of some ecological factors (host tree, diameter and decomposition degree of the dead wood and some microclimatic characteristics of sites on their occurrence and diversity. Investigations carried out in 2013 resulted in the identification of 44 lignicolous fungi species. Analysis of similarities between lingnicolous fungi species from the investigated natural reserves (by hierarchical clustering shows a separation of three fungi groups, depending on the host-trees species. The effect of the tree host species was highlighted also by detrended correspondence analysis, which, in addition presented the existence of an altitudinal gradient and a weaker effect of site conditions (slope and aspect and microclimatic variables (solar radiation on dead wood fungi occurrence. The effect of diameter and decomposition degree of fallen trunks and branches on dead wood fungi species was investigated using the redundancy analysis showing that wood debris with large surfaces are more easily colonized by the fungi species developing large sporocarps compared to small branches with low diameters colonized only by few or a single fungus species.

  1. Influence of the slope altitude-associated microclimate and light conditions on the physiological and biochemical processes in leaves of coastal forest trees

    Directory of Open Access Journals (Sweden)

    N. A. Khromykh

    2015-09-01

    Full Text Available The problem of natural forests conservation is relevant in the Ukrainian steppe zone where the forest ecosystems develop in the unfavorable conditions of geographic mismatch; therefore, they suffer as a result of any environmental changes. The hypothesis of susceptibility of tree leaves’ metabolism even to slight changes of climatic parameters was tested. The study was conducted in more than 75 years-old natural mixed forest located on the right bank of the Samara river. The chlorophyll (Chl content, and catalase (CAT, benzidine-peroxidase (BPOD and guaiacol-peroxidase (GPOD activities in leaves of autochthonous maple species (Acer platanoides L. and adventive acacia species (Robinia pseudoacacia L. were investigated on the lower (52 m above see level, a.s.l., middle (74 m a.s.l. and upper (96 m a.s.l. coastal slope altitude. In maple leaves decreasing chlorophyll amount on the middle and upper plots (8.8% and 19.5% compared with the lower plot together with Chla/Chlb ratio decrease (from 4.7 on the lower to 4.4 on the middle and 4.0 on the upper plots was found. Chlorophyll content in acacia leaves decreased only on the upper plot (by 8.5% compared to the lower one, and Chla/Chlb ratio on the lower and upper plots reached 5.1. In maple leaves the increase in altitude was accompanied by the decrease in BPOD activity (by 26% and 63% on the middle and upper plots, accordingly, and GPOD and CAT (accordingly, by 31% and 37% on the upper plots compared to the lower plots. High correlation coefficients of light, temperature and humidity with activity of CAT (respectively, r = –0.98; r = –0.85; r = 0.83, BPOD (r = –0.96; r = –0.93; r = 0.90 and GPOD (r = –0.98; r = –0.82; r = 0.82 were estimated in A. platanoides leaves. Sharp decline in GPOD activity in R. pseudoacacia leaves was revealed on the upper plot (by 95% compared to the lower one, whereas BPOD activity increased by 47% on the middle plot but decreased by 74% on the upper one

  2. Holocene precipitation in the subtropical Pacific inferred from the carbon isotope composition of Melaleuca quinquenervia (The Broad-leaved Paper Bark tree) leaves

    Science.gov (United States)

    Tibby, John; Barr, Cameron; Henderson, Andrew; Leng, Melanie; Marshall, Jon; McGregor, Glenn

    2013-04-01

    Holocene records of the amounts of subtropical precipitation are rare, particularly in the Southern Hemisphere. Yet such information is vital for a comprehensive understanding of global climate system dynamics. We present a precipitation record inferred from the δ13C composition of Melaleuca quinquenervia leaves retrieved from the Holocene sediments of Swallow Lagoon, North Stradbroke Island, in the subtropics of Australia. The modern relationship between rainfall and δ13C was quantified using a collection of monthly leaf falls between 1992 and 2003 and climate data. We then used the calibration to reconstruct precipitation variability from 7500 to 600 cal. yr BP. Dry phases at Swallow Lagoon in the early to mid Holocene are correlated with cooling in the North Atlantic Ocean (i.e. "Bond" events). This relationship breaks down after ~3500 cal. yr BP. From 3500 cal. yr BP there is increased aridity (and variability) associated with the mid- to late Holocene establishment of modern El Niño Southern Oscillation conditions. Overall, these data show linkages between precipitation in the low latitudes of the Southern Hemisphere and Northern Hemisphere cooling events, with a shift to internal forcing of subtropical climate via the Pacific Ocean in the late Holocene.

  3. Assessment of the urban trees health status on the base of nutrient and pigment content in their leaves

    OpenAIRE

    SLAVEYA PETROVA; LILYANA YURUKOVA; ILIANA VELCHEVA

    2014-01-01

    Town settlements have different load level by emissions originated mostly from transport, industry and heating system. Their environmental and climate conditions are more or less changed that effect to growth, physiology and vigor of woody plants at the city public vegetation areas. Our study on determining the impact of urban environment on the tree health status was focused on the quantities of nutrients and main components of the pigment complex – chlorophyll a, chlorophyll b and carotenoi...

  4. Natural isotopes abundance of 15N and 13C in leaves of some N2-fixing and non N2-fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    Variability in the natural abundance isotopes of 15N and 13C in leaves of several legume and non-legume plant species grown at different sites of two areas in semi-arid regions of Syria was determined. In the first area (non-saline soil), the 15N values of a number of fixing and non-fixing reference plants ranged from -2.09 to +9.46, depending on plant species and studied site. 15N in a number of legume species including Acacia cyanopylla (-1.73), Acacia farnesiana (-0.55), Prosopis juliflora (-1.64) and Medicago arborea (+1.6) were close to the atmospheric value pointing to a major contribution of N2 fixing in these species; whereas, those of reference plants were highly positive (between +3.6 and +9.46%). In the actinorhizal tree, Elaeagnus angustifolia, the 15N abundance was far lower (-0.46 to -2.1%) strongly suggesting that the plant obtained large proportional contribution from BNF. In contrast, δ15N values in some other legumes and actinorhizal plants were relatively similar to those of reference plants, suggesting that the contribution of fixed N2 is negligible. On the other hand, δ13C% values in leaves of C3 plants were affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were the same within each plant species although they were grown at different sites. Moreover, dual stable isotope analysis in leaves of Prosopis juliflora and other non- legumes grown on a salt affected soil (second area) was also conducted. Results showed that salinity did not affect C assimilation in this woody legume since a higher carbon discrimination was obtained indicating that this plant is a salt tolerant species; whereas, N2-fixation was drastically affected (δ15N= +7.03). (Author)

  5. Irradiance in young stands of Picea abies (L.) Karst. and Pinus sylvestris L. and the possibilities to prevent suckers of broad-leaved trees

    International Nuclear Information System (INIS)

    Incoming shortwave global radiation (Qg) and photosynthetically active radiation (PAR;Qpa) as a fraction of full daylight, relative irradiance (%Q), were measured at the same time in young stands of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). Measurements were made on three levels above ground: 20 cm above ground and 50 and 75% of stand height. Stands of three heights (75, 150 and 300 cm) were studied during two months. The stands were created by arranging young trees cut from natural stands, in nine quadratic spacings: 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 1.0, 1.4, and 2.0 m. The leaf area index (L) was estimated. Differences in %Q-values for Qpa and Qg in the same species at the same stand height and level of light measurements above ground were significant only in 150 and 300 cm stands. In 75 cm high stands of Scots pine, the %Q was less than 60% at spacings less than 0.2 m and in 75 cm high stands of Norway spruce, the %Q was less than 60% at spacings less than 0.3 m. Only at 0.1 x 0.1-0.3 x 0.3 m, %Q was less than 20% in Norway spruce stands. In 150 cm stands %Q less than 20% was measured at spacings less than 0.7 m in Norway spruce and less than 0.5 in Scots pine. In 300 cm stands of Norway spruce it was measured up to 1.2 and in Scots pine less than 1.1 m. Light extinction coefficients, K and Kg for spruce and pine stands were 0.17-0.40 and 0.16-0.31 respectively. Some practical implications of the study are presented. Lack of light (%Q less than 10%) as a single factor of seriously suppressed growth and development of broad-leaved plants and suckers by competition in young stands of spruce and pine only occur in dense stands 0.3 x 0.3-1.1 x 1.1 m (8000-100000 stems per hectare). Competition by light on a regenerated area generally occurs in the level of 50% of tree height (150-300 cm) and higher due to the rapid growth of broad-leaved trees (sprouts) compared with planted conifers but the light intensity at these levels %Q greater

  6. Ethnobotany, phytochemistry and pharmacological potential ofVitex negundo L. (five-leaved chaste tree):An updated review

    Institute of Scientific and Technical Information of China (English)

    Lubna Abidin; Aftab Ahmad; Shokat Rasool Mir; Mohd Mujeeb; Shah Alam Khan

    2015-01-01

    In the past two decades, a shift in paradigm has been observed in the development of new drugs from the plants for the treatment of diseases. Many scientists are focusing on the evidence based use of medicinal plants to develop pharmacotherapy for various human ailments. An important medicinal plant that has caught the attention of researchers all over the globe is Vitex negundo Linn. This plant is commonly used in various traditional systems of medicine like Ayurveda, Chinese, Siddha and Unani to treat various diseases and has been the subject of extensive research studies lately. Its roots and leaves are widely used in various disorders and illnesses such as skin eczema, ringworm, liver disorders, spleen enlargement, rheumatic pain, gout, abscess, backache etc. Seeds are also used as folklore medicine in bronchitis, eye disorders, female reproductive disorders, cold, dropsy, malarial fever and as demulcent. The current article is an effort to compile an updated review to disseminate knowledge and information among the scientific fraternity covering the progress made in the pharmacology and phytochemistry of this useful medicinal plant. This review on a very important traditional medicine,Vitex negundo L. can serve as a reference to the scientific community for their future research on this plant.

  7. Effects of atmospheric CO{sub 2} enrichment and foliar methanol application on net photosynthesis of sour orange tree (Citrus Aurantium; Rutaceae) leaves

    Energy Technology Data Exchange (ETDEWEB)

    Idso, S.B.; Garcia, R.L.; Kimball, B.A. [Water Conservation Lab., Phoenix, AR (United States); Idso, K.E.; Hoober, J.K. [Arizona State Univ., Tempe, AR (United States)

    1995-01-01

    Foliar spray applications of 40% aqueous methanol were made to sunlit leaves of sour orange trees that had been grown continuously in clear-plastic-wall open-top enclosures maintained out-of-doors at Phoenix, Arizona, for over 5.5 years in ambient air of approximately 400 {mu}mol mol{sup -1} CO{sub 2} and in air enriched with CO{sub 2} to a concentration of approximately 700 {mu}mol mol{sup -1}. No unambiguous effects of the methanol applications were detected in photosynthesis measurements made on foliage in either of the two CO{sub 2} treatments. THe 75% increase in CO{sub 2}, however, raised the upper-limiting leaf temperature for positive net photosynthesis by approximately 7 C, which resulted in a 75% enhancement in net photosynthesis at a leaf temperature of 31 C, a 100% enhancement at a leaf temperature of 35 C, and a 200% enhancement at 42 C. 13 refs., 2 figs., 1 tab.

  8. The efficacy of Chondrostereum purpureum as a biological control agent : A comparative analysis of the decay fungus (Chondrostereum purpureum), a chemical herbicide and mechanical cutting to control sprouting of broad-leaved tree species.

    OpenAIRE

    Lemola, Jan

    2014-01-01

    In forestry, manual control of broad-leaved trees is tedious and costly. To reduce costs, chemicals have been applied to keep these species in control. However, some chemicals are not recommended to use because of possibly adverse effects on the environment. Instead of chemicals, biological alternatives, such as a fungus, Chondrostereum purpureum, might be used to prevent sprouting. C. purpureum is a common decay fungus in Finland; it has been investigated at Metla, to find out whether it cou...

  9. Diary of a Tree.

    Science.gov (United States)

    Srulowitz, Frances

    1992-01-01

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

  10. A Preliminary Research on Morphological Characteristics of Branches and Leaves Diversity of Ancient Camphor-trees in Jiangxi Province%江西古樟枝叶形态多样性初探

    Institute of Scientific and Technical Information of China (English)

    黄萌; 陈尚钘; 杨光耀; 王宗德; 季春峰

    2014-01-01

    10 morphologic characters of 151 ancient camphor-tree leaves samples in Anyi, Anfu, Ruijin, Wuyuan and Yanshan of Jiangxi province were studied with the numerical taxonomic methods. The Q cluster analysis method wa applied to classify the 151 samples, and the ten characters were analyzed by R cluster as well as principal components analysis method. The result indicated that the ancient camphor-trees can not be divided into different groups based on the present samples and condition because the leaves' shape of ancient camphor-trees has high similarity. However, the shapes of ancient camphor-trees showed two types:the edge of leaves is waved or non-waved. This character has a strong regularity in the ancient camphor-trees leaves. It providea a favorable basis for the future study of system classification and evolution manner of the plants in Lauraceae.%选取10个形态学性状,应用数量分类学方法对江西省安义、安福、瑞金、婺源、铅山5个地区共151株古樟标本进行研究。将数量分类学中的Q聚类应用于5个地区共151份样本的分类,对选取的10个性状进行了R型聚类分析,且对这10个性状进行主成分分析。结果表明:同一地区以及不同地区的古樟之间的差异性不明显,也即古樟在枝叶形态上的相似度很大,依据现有样本和条件暂时无法把古樟分出不同的类群。不过古樟从性状上有两大类型,叶片存在边缘波状和不波的两种情况,此性状在古樟叶片中表现出较强的规律性。本研究为今后利用枝叶形态探讨樟科植物的系统分类和演化方式提供有利的依据。

  11. 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....

  12. The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch grown in the field and sugar beet (Beta vulgaris L. grown in hydroponics

    Directory of Open Access Journals (Sweden)

    Hamdi eEl-Jendoubi

    2014-01-01

    Full Text Available Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch trees grown in the field and sugar beet (Beta vulgaris L. cv. ‘Orbis’ grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated and basal (untreated leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

  13. Inferring the chemical form of 137Cs deposited by the Fukushima Dai-ichi Nuclear Power Plant accident by measuring (137)Cs incorporated into needle leaves and male cones of Japanese cedar trees.

    Science.gov (United States)

    Kanasashi, Tsutomu; Takenaka, Chisato; Sugiura, Yuki

    2016-05-15

    We hypothesized that the water-soluble (ionic) and water-insoluble (stable) radiocesium from the initial fallout of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident was distributed in various proportions in the surrounding areas and that this distribution was reflected in the trees that suffered deposition from the initial fallout. This study attempted to evaluate local variations in the chemical form of (137)Cs derived from the initial fallout of the FDNPP accident and whether its chemical form affected the radiocesium concentration in the tissues currently growing in trees, even after the initial fallout ceased. For these estimations, the ratio between the (137)Cs concentration in Cryptomeria japonica needle leaves in the tree crown, which existed before the FDNPP accident and subsequently directly exposed to the initial fallout ((137)Cs pre-accident N), and the amount of (137)Cs in the initial fallout itself ((137)Cs fallout) was determined ((137)Cs pre-accident N/(137)Cs fallout) at 66 sites. In addition, the (137)Cs ratios between the male cones produced in 2012 ((137)Cs male cone) and needle leaves that had elongated in the spring of 2011 ((137)Cs 2011N) was determined at 82 sites ((137)Cs male cone/(137) Cs 2011N). Most of the sites with lower (137)Cs pre-accident N /(137)Cs fallout ratios were distributed in eastern Fukushima, relatively close to the Pacific Ocean coastline. Lower (137)Cs pre-accident N/(137)Cs fallout and higher (137)Cs malecone/(137)Cs 2011N were found to be associated with higher proportions of (137)Cs in ionic forms. These observations are consistent with the hypothesis, and likely reflect regional variations in the chemical form of the deposited radiocesium. PMID:26990074

  14. Antioxidant properties of various solvent extracts of total phenolic constituents from three different agroclimatic origins of drumstick tree (Moringa oleifera Lam.) leaves.

    Science.gov (United States)

    Siddhuraju, Perumal; Becker, Klaus

    2003-04-01

    Water, aqueous methanol, and aqueous ethanol extracts of freeze-dried leaves of Moringa oleifera Lam. from different agroclimatic regions were examined for radical scavenging capacities and antioxidant activities. All leaf extracts were capable of scavenging peroxyl and superoxyl radicals. Similar scavenging activities for different solvent extracts of each collection were found for the stable 1,1-diphenyl 2-picrylhydrazyl (DPPH(*)) radical. Among the three different moringa samples, both methanol and ethanol extracts of Indian origins showed the highest antioxidant activities, 65.1 and 66.8%, respectively, in the beta-carotene-linoleic acid system. Nonetheless, increasing concentration of all the extracts had significantly (P flavonoid groups such as quercetin and kaempferol. On the basis of the results obtained, moringa leaves are found to be a potential source of natural antioxidants due to their marked antioxidant activity. This is the first report on the antioxidant properties of the extracts from freeze-dried moringa leaves. Overall, both methanol (80%) and ethanol (70%) were found to be the best solvents for the extraction of antioxidant compounds from moringa leaves. PMID:12670148

  15. A rabies vaccine adjuvanted with saponins from leaves of the soap tree (Quillaja brasiliensis) induces specific immune responses and protects against lethal challenge.

    Science.gov (United States)

    Yendo, Anna Carolina A; de Costa, Fernanda; Cibulski, Samuel P; Teixeira, Thais F; Colling, Luana C; Mastrogiovanni, Mauricio; Soulé, Silvia; Roehe, Paulo M; Gosmann, Grace; Ferreira, Fernando A; Fett-Neto, Arthur G

    2016-04-29

    Quillaja brasiliensis (Quillajaceae) is a saponin producing species native from southern Brazil and Uruguay. Its saponins are remarkably similar to those of Q. saponaria, which provides most of the saponins used as immunoadjuvants in vaccines. The immunostimulating capacities of aqueous extract (AE) and purified saponin fraction (QB-90) obtained from leaves of Q. brasiliensis were favorably comparable to those of a commercial saponin-based adjuvant preparation (Quil-A(®)) in experimental vaccines against bovine herpesvirus type 1 and 5, poliovirus and bovine viral diarrhea virus in mice model. Herein, the immunogenicity and protection efficacy of rabies vaccines adjuvanted with Q. brasiliensis AE and its saponin fractions were compared with vaccines adjuvanted with either commercial Quil-A or Alum. Mice were vaccinated with one or two doses (on days 0 and 14) of one of the different vaccines and serum levels of total IgG, IgG1 and IgG2a were quantified over time. A challenge experiment with a lethal dose of rabies virus was carried out with the formulations. Viral RNA detection in the brain of mice was performed by qPCR, and RNA copy-numbers were quantified using a standard curve of in vitro transcribed RNA. All Q. brasiliensis saponin-adjuvanted vaccines significantly enhanced levels of specific IgG isotypes when compared with the no adjuvant group (P≤0.05). Overall, one or two doses of saponin-based vaccine were efficient to protect against the lethal rabies exposure. Both AE and saponin fractions from Q. brasiliensis leaves proved potent immunological adjuvants in vaccines against a lethal challenge with a major livestock pathogen, hence confirming their value as competitive or complementary sustainable alternatives to saponins of Q. saponaria. PMID:27032516

  16. Atividade de extrato aquoso de folhas de nim (Azadirachta indica sobre Spodoptera frugiperda Activity of neem tree (Azadirachta indica leaves aqueous extract on Spodoptera frugiperda

    Directory of Open Access Journals (Sweden)

    Hélio Teixeira Prates

    2003-03-01

    Full Text Available A lagarta-do-cartucho do milho (Spodoptera frugiperda (J. E. Smith tem sido controlada com inseticidas sintéticos. Uma das caracteristicas do nim (Azadirachta indica A. Juss é sua atividade inseticida contra pragas, como sucedâneo aos sintéticos. O objetivo deste trabalho foi avaliar a atividade inseticida do extrato aquoso das folhas do nim sobre a lagarta-do-cartucho do milho, em laboratório. Bioensaios com diferentes concentrações de extrato em dieta artificial, tendo o inseticida chlorpyrifos como testemunha, revelaram, 15 dias após infestação com larvas, eficiência equivalente entre as concen- trações 3,60 a 10,00 mg mL-1. A análise de Probit mostrou CL50 = 2,67 mg mL-1; o extrato aquoso das folhas de nim apresenta, portanto, efeito inseticida sobre a lagarta-do-cartucho do milho.The fall armyworm (Spodoptera frugiperda (J. E. Smith has been controlled with synthetic insecticides bringing risk to the environment. Neem (Azadirachta indica A. Juss is reported to be a natural alternative to synthetic insecticides against many insect species. The objective of this work was to evaluate the activity of neem leaves aqueous extract on fall armyworm, in laboratory. Bioassays carried out using artificial feed with various extract concentrations, and chlorpyrifos as control, indicated, 15 days after larvae infestation, similar efficiency in concentrations from 3.60 to 10.00 mg mL-1. Probit analysis showed LC50 = 2.67 mg mL-1. Hence, aqueous extract from neem leaves are active against fall armyworm.

  17. Natural abundances of 15N and 13C in leaves of some N2-fixing and non-N2-fixing trees and shrubs in Syria.

    Science.gov (United States)

    Kurdali, F; Al-Shamma'a, M

    2009-09-01

    A survey study was conducted on man-made plantations located at two different areas in the arid region of Syria to determine the variations in natural abundances of the (15)N and (13)C isotopes in leaves of several woody legume and non-legume species, and to better understand the consequence of such variations on nitrogen fixation and carbon assimilation. In the first study area (non-saline soil), the delta(15)N values in four legume species (Acacia cyanophylla,-1.73 per thousand Acacia farnesiana,-0.55 per thousand Prosopis juliflora,-1.64 per thousand; and Medicago arborea,+1.6 \\textperthousand) and one actinorhizal plant (Elaeagnus angustifolia,-0.46 to-2.1 per thousand) were found to be close to that of the atmospheric value pointing to a major contribution of N(2) fixing in these species; whereas, delta(15)N values of the non-fixing plant species were highly positive. delta(13)C per thousand; in leaves of the C3 plants were found to be affected by plant species, ranging from a minimum of-28.67 per thousand; to a maximum of-23 per thousand. However, they were relatively similar within each plant species although they were grown at different sites. In the second study area (salt affected soil), a higher carbon discrimination value (Delta(13)C per thousand) was exhibited by P. juliflora, indicating that the latter is a salt tolerant species; however, its delta(15)N was highly positive (+7.03 per thousand) suggesting a negligible contribution of the fixed N(2). Hence, it was concluded that the enhancement of N(2) fixation might be achieved by selection of salt-tolerant Rhizobium strains. PMID:20183233

  18. Natural abundances of 15N and 13C in leaves of some N2- fixing and non N2- fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    A survey study was conducted on man-made plantations located at two different areas in the arid region of Syria to determine the variations in natural abundances of the 12N and 13C isotopes in leaves of several woody legume and non-legume species, and to better understand the consequence of such variations on nitrogen fixation and carbon assimilation. In the first study area (non-saline soil), the δ15N values in four legume species (Acacia cyanopylla, -1.73 %; Acacia farnesiana, -0.55%; Prosopis juliflora, -1.64%, and Medicago arborea, +1.6%) and one actinorhizal plant (Elaeagnus angustifolia, -0.46 to -2.1%) were found to be close to that of the atmospheric value pointing to a major contribution of N2 fixing in these species; whereas, δ15N values of the non-fixing plant species were highly positive.δ13C% in leaves of the C3 plants were found to be affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were relatively similar within each plant species although they were grown at different sites. In the second study area (salt affected soil) a higher carbon discrimination value (Δ3C%) was exhibited by Prosopis juliflora indicating that the latter is a salt tolerant species; however, its δ 15N was highly positive (+7.03%) suggesting a negligible contribution of the fixed N2. Hence, it was concluded that the enhancement of N2 fixation might be achieved by selection of salt-tolerant rhizobium strains. (author)

  19. Taking Leave?

    CERN Document Server

    2000-01-01

    Planning a holiday? Then if you're a member of the personnel, you'll need to use the Laboratory's new leave system that will be put in place on 1 October. Leave allocations don't change - you are entitled to just as much holiday as before - but instead of being credited annually, your leave will be credited on a monthly basis, and this information will be communicated on your salary slip. The reason for the change is that with the various new leave schemes such as Recruitment by Saved Leave (RSL) and the Progressive Retirement Programme (PRP), a streamlined procedure was required for dealing with all kinds of leave. In the new system, each member of the personnel will have leave accounts to which leave will be credited monthly from the payroll and debited each time an absence is registered in the CERN Electronic Document Handling system (EDH). Leave balances will appear on monthly pay slips, and full details of leave transactions and balances will be available through EDH at all times. As the leave will be c...

  20. Effects of micro-topographies on stand structure and tree species diversity in an old-growth evergreen broad-leaved forest, southwestern Japan

    Directory of Open Access Journals (Sweden)

    Tran Van Do

    2015-07-01

    Full Text Available Stand structure and species diversity were studied in correspondence with micro-topographies in an old-growth forest in southwestern Japan. The study was conducted in a 200×200m2 permanent plot, which were divided into 400 subplots using grids of 10m×10m. Subplots were categorized to four micro-topographies as crest slope (CS, head hollow (HH, upper slope (US and lower slope (LS, basing on slope of forest floor and plot position, and to two elevational zones as below 450 m and above 450 m. Tree censuses for all individuals with diameter at breast height (DBH ⩾ 5 cm were conducted in 2009 and 2013. The results indicated that CS had subplot means of living stems, dead stems, DBH, basal area (G, and basal area increment (▵G significantly higher than that in LS. While, means of recruited stems and Shannon diversity index were significantly lower. Comparing between below and above 450 m elevational zones indicated the significantly higher parameters of stand structure and species diversity in above 450 m elevational zone. The differences of edaphic conditions led to difference of density of living stems, species density, DBH, G, and ▵G among micro-topographies. Therefore, crest slope, upper slope, and higher elevational zones should be encouraged for the purposes of carbon accumulation and storage. While, the lower elevational zones should be used for the purposes of species diversity conservation.

  1. Different Methods of Extracting Invertase from the Leaves of Hevea brasiliensis(Para Rubber Tree)%橡胶树叶片转化酶提取方法的比较

    Institute of Scientific and Technical Information of China (English)

    蓝基贤; 何慧; 戚继艳; 唐朝荣

    2012-01-01

    比较液氮研磨样品与蛋白抽提液研磨样品对6种提取橡胶树叶片转化酶方法的效果.结果表明:液氮研磨法对转化酶活性影响很大,特别是中性/碱性转化酶和细胞壁结合的酸性转化酶已基本失活,而可溶性酸性转化酶活性丧失也比较严重.利用蛋白抽提液研磨样品,用Hepes-NaOH法提取的可溶性转化酶的酶活性最高,达472.44 μmol (glucose)/[g (FW)·h];虽然磷酸-柠檬酸法获得的粗酶液的蛋白含量较低,但其酶活性高达441.61 μmol( glucose)/[g( FW)·h];Tris-HCl法提取的细胞壁结合酸性转化酶的酶活性最高,达35.83 μmol( glucose)/[g(FW)·h].从转化酶的比活力看,磷酸-柠檬酸法最佳,所提取的叮溶性转化酶比活力约为Hepes-NaOH法的4倍.本研究结果为进一步完善橡胶树叶片转化酶的提取方法提供重要的指导意义.%Six methods were investigated in extracting invertase from the leaves of rubber tree(Hevea brasiliensis Muell. Arg)by two ways of grinding leaves: liquid nitrogen and extraction buffer. Grinding leaves in liquid nitrogen seriously destroyed the activities of invertases, especially those of neutral/alkaline invertase and cell wall-bound invertase which were totally inactivated. In comparison, the way of grinding leaves in extraction buffers was suitable for extracting various types of invertase. After the leaves were ground in extraction buffers, the activity of crude soluble invertase extracted by Hepes -NaOH method revealed to be the highest, being 472.44 u.mol (glucose )/[g (FW) o h]. Despite low protein yields obtained by phosphate -citrate method, the resulting invertase activity was as high as 441.61 μmol (glucose)/[g(FW) ·h]. Regarding the cell wall-bound invertase, Tris-HCl method was the most suitable, resulting in invertase activity of 35.83 μmol (glucose )/[g (FW)·h]. With regard to specific enzymatic activity, the phosphate-citrate method was the most appropriate, with specific

  2. Comparison of heavy metal contents in their leaves by 17 road afforestation trees%17种道路绿化树木叶片重金属镉和铬含量的比较研究

    Institute of Scientific and Technical Information of China (English)

    刘冰

    2014-01-01

    The urban road green trees could absorb heavy metal pollutants in the atmosphere.The heavy metals Cd and Cr contents in leaves of 17 virescence trees in Xinxiang City are analysed.The results indicate that the same road afforestation trees show different heavy metal contents in their leaves,polluted area > clear area, Autumn > Spring, Cd > Cr; simultaneously different species show quite different contents to the same heavy metal element,the content of Cd is in the order of Populus alba >Acer mono >Populus tomentosa > Ligustrum quihoui Carr > Ligustrum lucidum > Prunus ceraifera > Euonymus j aponicus > Koelreuteria paniculata > P latanus acerifolia > Ailanthus altissima > Broussonetia papyrifera > Fraxinus chinensis > Sophora j aponica > Photinia frasery > Pittosporum tobira >Yucca gloriosa >Buxus microphylla;the content of Cr is in the order of Acer mono > Populus tomentosa >Populus alba > Prunus ceraifera > Buxus microphylla > Photinia frasery > P latanus acerifolia >Sophora j aponica >Yucca gloriosa >Broussonetia papyrifera >Ligustrum quihoui Carr >Pittosporum tobira >Koelreuteria paniculata >Ligustrum lucidum >Ailanthus altissima >Fraxinus chinensis >Buxus megistophylla .The afforest trees are classified three at the basis of the content of Cd and Cr,the first category includes Populus tomentosa and Acer mono ;Prunus ceraiferai ,P latanus acerifolia ,Populus alba ,Buxus microphylla and Photinia frasery belong to the second category;the third category includes Fraxinus chinensis ,Sophora j aponica ,Broussonetia papyrifera ,Ailanthus altissima ,Koelreuteria paniculata , Pittosporum tobira ,Yucca gloriosa , Euonymus j aponicus , Ligustrum lucidum and Ligustrum quihoui Carr . Heavy metal contents in road green trees leaves show markedly difference depending on function areas,seasons,heavy metal kinds and tree species.%对新乡市17种道路绿化树木叶片重金属镉和铬的含量进行了分析,结果表明,同种道路绿化树木叶片的重金属含

  3. Natural isotopes abundance of sup 1 sup 5 N and sup 1 sup 3 C in leaves of some N sub 2 -fixing and non N sub 2 -fixing trees and shrubs in Syria

    International Nuclear Information System (INIS)

    Varability in the natural abundance isotopes of sup 1 sup 5 N and sup 1 sup 3 C in leaves of several legume and non-legume plant species grown at different sites of two areas in semi-arid regions of Syria was determined. In the first area (non-saline soil), the sup 1 sup 5 N values of a number of fixing and non-fixing reference plants ranged from -2.09 to +9.46, depending on plant species and studied site. sup 1 sup 5 N in a number of legume species including Acacia cyanopylla (-1.73), Acacia farnesiana (-0.55), Prosopis juliflora (-1.64) and Medicago arborea (+1.6) were close to the atmospheric value pointing to a major contribution of N sub 2 fixing in these species; whereas, those of reference plants were highly positive (between +3.6 and +9.46%). In the actinorhizal tree, Elaeagnus angustifolia, the sup 1 sup 5 N abundance was far lower (-0.46 to -2.1%) strongly suggesting that the plant obtained large proportional contribution from BNF. In contrast, delta sup 1 sup 5 N values in some other legumes and actinorhizal plants were relatively similar to those of reference plants, suggesting that the contribution of fixed N sub 2 is negligible. On the other hand, delta sup 1 sup 3 C% values in leaves of C3 plants were affected by plant species, ranging from a minimum of -28.67% to a maximum of -23%. However, they were the same within each plant species although they were grown at different sites. Moreover, dual stable isotope analysis in leaves of Prosopis juliflora and other non- legumes grown on a salt affected soil (second area) was also conducted. Results showed that salinity did not affect C assimilation in this woody legume since a higher carbon discrimination was obtained indicating that this plant is a salt tolerant species; whereas, N2-fixation was drastically affected (delta sup 1 sup 5 N= +7.03). (Author)

  4. Tree sets

    OpenAIRE

    Diestel, Reinhard

    2015-01-01

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

  5. Misunderstanding sap ascent in trees

    OpenAIRE

    Cochard, Hervé; Delzon, Sylvain

    2013-01-01

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

  6. Gene tree correction for reconciliation and species tree inference

    Directory of Open Access Journals (Sweden)

    Swenson Krister M

    2012-11-01

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

  7. Impact of African weaver ant nests [Oecophylla longinoda Latreille (Hymenoptera: Formicidae)] on Mango [Mangifera indica L. (Sapindales: Anacardiaceae)] leaves

    OpenAIRE

    Anato, Florence; Sinzogan, Antonio; Adandonon, Appolinaire; Hounlidji, Xavier; Offenberg, Joachim; Kossou, Dansou; Vayssières, Jean-Francois

    2015-01-01

    Oecophylla ants are appreciated for their control of pests in plantation crops. However, the ants´ nest building may have negative impacts on trees. In this study we tested the effect of ant densities and nest building on the leaf performance of mango trees. Trees were divided into three groups: trees without ants, trees with low and trees with high ant densities. Subsequently, the total number of leaves, the proportion of leaves used for nest construction, and tree growth was compared betwee...

  8. Asymptotic analysis of Hoppe trees

    CERN Document Server

    Leckey, Kevin

    2012-01-01

    We introduce and analyze a random tree model associated to Hoppe's urn. The tree is built successively by adding nodes to the existing tree when starting with the single root node. In each step a node is added to the tree as a child of an existing node where these parent nodes are chosen randomly with probabilities proportional to their weights. The root node has weight $\\vartheta>0$, a given fixed parameter, all other nodes have weight 1. This resembles the stochastic dynamic of Hoppe's urn. For $\\vartheta=1$ the resulting tree is the well-studied random recursive tree. We analyze the height, internal path length and number of leaves of the Hoppe tree with $n$ nodes as well as the depth of the last inserted node asymptotically as $n\\to \\infty$. Mainly expectations, variances and asymptotic distributions of these parameters are derived.

  9. Tea tree oil.

    Science.gov (United States)

    Larson, David; Jacob, Sharon E

    2012-01-01

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

  10. Prospeção de inibidores de serinoproteinases em folhas de leguminosas arbóreas da floresta Amazônica Prospecting serine proteinase inhibitors in leaves from leguminous trees of the Amazon forest

    Directory of Open Access Journals (Sweden)

    Larissa Ramos Chevreuil

    2011-03-01

    , Leucaena leucocephala, Ormosia paraensis, Parkia multijuga, P. pendula, P. platycephala, Swartzia corrugata and S. polyphylla. Leaves were collected, dried at 30ºC for 48 h, crushed and subjected to extraction with NaCl (0.15 M, 10% w/v, resulting in the total extract. Tests were performed to determine the concentration of proteins and to detect of inhibitory activity against bovine trypsin and chymotrypsin. The content of crude and soluble protein in leaf extracts varied from 7.9 to 31.2% and 1.3 to 14.8%, respectively. The inhibitory activity on trypsin and chymotrypsin was observed in all leaf extracts. However, in extracts of E. maximum, L. leucocephala, P. pendula, S. corrugata and S. polyphylla, the inhibition was greater on trypsin, while extract of P. multijuga was more effective against chymotrypsin. We conclude that leaf extracts of leguminous trees have serine proteinase inhibitors and show potential biotecnological applications.

  11. Nutrient cycling in mango trees

    Directory of Open Access Journals (Sweden)

    Cinara Xavier de Almeida

    2014-02-01

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

  12. The Hill and the Trees

    Institute of Scientific and Technical Information of China (English)

    王燕文

    2007-01-01

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

  13. Planting Trees

    OpenAIRE

    Relf, Diane

    2009-01-01

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

  14. Simplifying gene trees for easier comprehension

    Directory of Open Access Journals (Sweden)

    Mundry Marvin

    2006-04-01

    Full Text Available Abstract Background In the genomic age, gene trees may contain large amounts of data making them hard to read and understand. Therefore, an automated simplification is important. Results We present a simplification tool for gene trees called TreeSimplifier. Based on species tree information and HUGO gene names, it summarizes "monophyla". These monophyla correspond to subtrees of the gene tree where the evolution of a gene follows species phylogeny, and they are simplified to single leaves in the gene tree. Such a simplification may fail, for example, due to genes in the gene tree that are misplaced. In this way, misplaced genes can be identified. Optionally, our tool glosses over a limited degree of "paraphyly" in a further simplification step. In both simplification steps, species can be summarized into groups and treated as equivalent. In the present study we used our tool to derive a simplified tree of 397 leaves from a tree of 1138 leaves. Comparing the simplified tree to a "cartoon tree" created manually, we note that both agree to a high degree. Conclusion Our automatic simplification tool for gene trees is fast, accurate, and effective. It yields results of similar quality as manual simplification. It should be valuable in phylogenetic studies of large protein families. The software is available at http://www.uni-muenster.de/Bioinformatics/services/treesim/.

  15. Environmental fate of emamectin benzoate after tree micro injection of horse chestnut trees.

    Science.gov (United States)

    Burkhard, Rene; Binz, Heinz; Roux, Christian A; Brunner, Matthias; Ruesch, Othmar; Wyss, Peter

    2015-02-01

    Emamectin benzoate, an insecticide derived from the avermectin family of natural products, has a unique translocation behavior in trees when applied by tree micro injection (TMI), which can result in protection from insect pests (foliar and borers) for several years. Active ingredient imported into leaves was measured at the end of season in the fallen leaves of treated horse chestnut (Aesculus hippocastanum) trees. The dissipation of emamectin benzoate in these leaves seems to be biphasic and depends on the decomposition of the leaf. In compost piles, where decomposition of leaves was fastest, a cumulative emamectin benzoate degradation half-life time of 20 d was measured. In leaves immersed in water, where decomposition was much slower, the degradation half-life time was 94 d, and in leaves left on the ground in contact with soil, where decomposition was slowest, the degradation half-life time was 212 d. The biphasic decline and the correlation with leaf decomposition might be attributed to an extensive sorption of emamectin benzoate residues to leaf macromolecules. This may also explain why earthworms ingesting leaves from injected trees take up very little emamectin benzoate and excrete it with the feces. Furthermore, no emamectin benzoate was found in water containing decomposing leaves from injected trees. It is concluded, that emamectin benzoate present in abscised leaves from horse chestnut trees injected with the insecticide is not available to nontarget organisms present in soil or water bodies. PMID:25363584

  16. The lattice dimension of a tree

    OpenAIRE

    Ovchinnikov, Sergei

    2004-01-01

    The lattice dimension of a graph G is the minimal dimension of a cubic lattice in which G can be isometrically embedded. We prove that the lattice dimension of a tree with n leaves is $\\lceil n/2 \\rceil$.

  17. Development and Leaf Consumption by Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) Reared on Leaves of Agroenergy Crops.

    Science.gov (United States)

    Cabezas, M F; Nava, D E; Geissler, L O; Melo, M; Garcia, M S; Krüger, R

    2013-12-01

    Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae) is a polyphagous pest that threatens more than 24 species of crop plants including those used for biodiesel production such as Ricinus communis (castor bean), Jatropha curcas (Barbados nut), and Aleurites fordii (tung oil tree). The development and leaf consumption by S. cosmioides reared on leaves of these three species were studied under controlled laboratory conditions. The egg-to-adult development time of S. cosmioides was shortest when reared on castor bean leaves and longest when reared on tung oil tree leaves. Larvae reared on castor bean and Barbados nut leaves had seven instars, whereas those reared on tung oil tree leaves had eight. Females originating from larvae reared on castor bean and Barbados nut leaves showed greater fecundity than did females originating from larvae reared on tung oil tree leaves. Insects fed on castor bean leaves had shorter life spans than those fed on tung oil tree and Barbados nut leaves although the oviposition period did not differ significantly. The intrinsic and finite rates of increase were highest for females reared on castor bean leaves. Total leaf consumption was highest for larvae reared on tung oil tree leaves and lowest for those reared on Barbados nut leaves. We conclude that castor bean is a more appropriate host plant for the development of S. cosmioides than are Barbados nut and tung oil tree. PMID:27193276

  18. Effect of the air pollution by heavy metals in the tree leaves in the metropolitan area of Toluca Valley; Efecto de la contaminacion atmosferica por metales pesados en las hojas de los arboles de la zona metropolitana del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Ledesma O, C. I.

    2014-07-01

    Leaves of two tree species: Juniperus sp and Ligustrum sp were studied as indicators of pollution heavy metals (Mn, Fe, Cu, Zn and Pb) in the atmosphere of the Metropolitan Area of the Toluca Valley. Bio markers of catalase, superoxide dismutase, ascorbate peroxidase, guaiacol, proteins and pigments were measured in order to determine the effects to atmospheric stress caused by heave metals during two periods in the year (December 2012 and May 2013). Metals were quantified in dry deposit and tissue on trees tissue leaves using the technique of Energy Dispersive X-ray Fluorescence Spectroscopy and Total Reflection X-ray Fluorescence Spectroscopy respectively. The results show greater response of enzyme inhibition in Juniperus sp. species, with decreased protein content and increased lipid peroxidation at sites with higher content of metals in tissue belonging to urban areas with increased industrial activity and traffic flow. In dry deposit bioavailability factor of metals was Fe>Mn> Zn> Cu>Pb for the first time of sampling and Fe>Mn> Cu> Zn>Pb for the second sampling period. (Author)

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

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.

    2010-01-01

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

  20. Características funcionais de folhas de sol e sombra de espécies arbóreas em uma mata de galeria no Distrito Federal, Brasil Leaf functional traits in sun and shade leaves of gallery forest trees in Distrito Federal, Brazil

    Directory of Open Access Journals (Sweden)

    Davi Rodrigo Rossatto

    2010-09-01

    nutritional aspects of shade and sun leaves, in ten tree species commonly found in gallery forests. Relative to shade leaves, sun leaves had higher values of CO2 assimilation rates on an area basis (Aarea, of stomatal conductance (gs, of quantum yield of Photosystem II (ΦPSIIL; and a larger fraction of PSII centers in the open state (qL, while shade leaves showed higher specific leaf area. However, shade and sun leaves did not differ in terms of leaf water potential, CO2 assimilation on a mass basis and in leaf concentrations of macronutrients. ΦPSII and gs were the main factors that influenced Aarea in sun leaves, while only ΦPSII significantly affected Aarea of shade leaves. The differences found here demonstrate that, like in other forest formations worldwide, gallery forest trees are able to acclimate to contrasting irradiance levels that typically occur in this type of environment.

  1. 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)…

  2. The Biology of Ageing in Leaves.

    Science.gov (United States)

    Gill, John; And Others

    1988-01-01

    Describes laboratory procedures for observing the progressive change deciduous leaves undergo prior to abscission. Outlines the starch test, sugar test, extraction and chromatography of pigments, and experimental results. States that obtained results enable the events of leaf senescence to be correlated with the carbohydrate economy of a tree in…

  3. A suffix tree or not a suffix tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    In this paper we study the structure of suffix trees. Given an unlabeled tree τ on n nodes and suffix links of its internal nodes, we ask the question “Is τ a suffix tree?”, i.e., is there a string S whose suffix tree has the same topological structure as τ? We place no restrictions on S, in...... particular we do not require that S ends with a unique symbol. This corresponds to considering the more general definition of implicit or extended suffix trees. Such general suffix trees have many applications and are for example needed to allow efficient updates when suffix trees are built online. Deciding...... if τ is a suffix tree is not an easy task, because, with no restrictions on the final symbol, we cannot guess the length of a string that realizes τ from the number of leaves. And without an upper bound on the length of such a string, it is not even clear how to solve the problem by an exhaustive...

  4. Watch out for the leaves!

    CERN Multimedia

    HSE Unit

    2013-01-01

    Now that autumn is here, dead leaves falling from the trees form a colourful carpet that is pleasing to the eye. However, the reality is less pleasant for pedestrians, since these leaves increase the risk of slipping and falling, especially when the ground is wet.   These conditions are also hazardous for two- and four-wheeled vehicles, whose grip on the ground can be severely reduced, thereby increasing the risk of them skidding out of control. Cyclists are among the most vulnerable road users when faced with these hazards. It is therefore essential to be alert to the dangers, which can be lessened by taking a few simple precautions such as moderating your speed and wearing suitable shoes. We also invite you to notify the Service Desk if you notice a road or pavement where there is a high concentration of dead leaves. The CERN Roads and Drainage Service will then ensure that the leaves are cleared in order to reduce the risk of accidents in the area.

  5. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

    Science.gov (United States)

    Madrigal-González, Jaime; Ruiz-Benito, Paloma; Ratcliffe, Sophia; Calatayud, Joaquín; Kändler, Gerald; Lehtonen, Aleksi; Dahlgren, Jonas; Wirth, Christian; Zavala, Miguel A.

    2016-01-01

    Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation. PMID:27571971

  6. Holy Trees

    OpenAIRE

    Elosua, Miguel

    2013-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

  8. Hevea Leaves Boundary Identification based on Morphological Transformation and Edge Detection Features

    Directory of Open Access Journals (Sweden)

    Sule Tekkesinoglu

    2014-03-01

    Full Text Available The goal of this study is to present a concept to identify overlapping rubber tree (Hevea brasiliensis-scientific name leaf boundaries. Basically rubber tree leaves show similarity to each other and they may contain similar information such as color, texture or shape of leaves. In fact rubber tree leaves are naturally in class of palmate leaves, it means that numbers of leaves are joining at their base. So it reflects the information of the position of the leaves whether the leaves are overlapped or separated. Therefore, this unique feature could be used to distinguish particular leaves from others clone to identify the type of trees. This study addresses the problem of identifying the overlapped leaves with complex background. The morphological transformation is often applied in order to obtain the foreground object and the background location as well. However, it does not yield satisfactory results in order to get boundaries information. This study, presents on improved approach to identify boundary of rubber tree leaves based on morphological operation and edge detection methods. The outcome of this fused algorithm exhibits promising results for identifying the leaf boundaries of rubber trees.

  9. Gas exchange characteristics in leaves of the Euphorbiacea Aleurites montana as consequence of growth under 700 ppm CO2 in air. A study on photosynthesis and photorespiration in the Chinese tung-oil tree

    International Nuclear Information System (INIS)

    Three months old plants of the Chinese tung-oil tree Aleurites montana (Euphorbiaceae) were cultivated for 4 months in air containing 700 ppm CO2. These plants, which grow substantially better in the CO2-enriched atmosphere, were analyzed by mass spectrometry for photosynthesis and photorespiration together with control plants grown all the time in normal (350 ppm CO2) air. Thereafter part of the plants was subjected for two weeks to 0.3 ppm SO2 in the atmosphere and again analyzed for photosynthesis and photorespiration. Gas exchange measurements carried out by mass spectrometry show that the ratio of O2 evolved to CO2 fixed is about 0.5. Apparently, part of the CO2 fixed is channelled into a metabolic path without concomitant O2-evolution. Although the plant has no succulent appearance, apparently a Crassulacean type metabolism is performed. When Aleurites plants grown all the time in normal air with 350 ppm, are exposed for two weeks to 0.3 ppm SO2 the treatment completely inhibits this CO2-fixing portion. When Aleurites plants, grown for 4 months in a CO2-enriched atmosphere of 700 ppm CO2, are subjected for two weeks to 0.3 ppm SO2, the features of control plants show up again. When these plants are tested under 350 ppm CO2 the Crassulacean type CO2-fixation apparently is not inhibited by SO2. Photorespiration, although low, is present in the same activity as in the controls. Seemingly, an increased level of CO2 in air trends to alleviate the impact of the SO2 at least in the Chinese tung-oil tree. (orig./MG)

  10. Gas exchange characteristics in leaves of the Euphorbiacea Aleurites montana as consequence of growth under 700 ppm CO{sub 2} in air. A study on photosynthesis and photorespiration in the Chinese tung-oil tree

    Energy Technology Data Exchange (ETDEWEB)

    He, P. [Central South Forestry Univ., Zhuzhou/Hunan (China); Bader, K.P.; Radunz, A.; Schmid, G.H. [Bielefeld Univ. (Germany). Lehrstuhl fuer Zellphysiologie; Kahmann, U.; Ruppel, G.H. [Bielefeld Univ. (Germany). Abt. fuer Morphologie der Pflanzen und Feinbau der Zelle

    1998-03-01

    Three months old plants of the Chinese tung-oil tree Aleurites montana (Euphorbiaceae) were cultivated for 4 months in air containing 700 ppm CO{sub 2}. These plants, which grow substantially better in the CO{sub 2}-enriched atmosphere, were analyzed by mass spectrometry for photosynthesis and photorespiration together with control plants grown all the time in normal (350 ppm CO{sub 2}) air. Thereafter part of the plants was subjected for two weeks to 0.3 ppm SO{sub 2} in the atmosphere and again analyzed for photosynthesis and photorespiration. Gas exchange measurements carried out by mass spectrometry show that the ratio of O{sub 2} evolved to CO{sub 2} fixed is about 0.5. Apparently, part of the CO{sub 2} fixed is channelled into a metabolic path without concomitant O{sub 2}-evolution. Although the plant has no succulent appearance, apparently a Crassulacean type metabolism is performed. When Aleurites plants grown all the time in normal air with 350 ppm, are exposed for two weeks to 0.3 ppm SO{sub 2} the treatment completely inhibits this CO{sub 2}-fixing portion. When Aleurites plants, grown for 4 months in a CO{sub 2}-enriched atmosphere of 700 ppm CO{sub 2}, are subjected for two weeks to 0.3 ppm SO{sub 2}, the features of control plants show up again. When these plants are tested under 350 ppm CO{sub 2} the Crassulacean type CO{sub 2}-fixation apparently is not inhibited by SO{sub 2}. Photorespiration, although low, is present in the same activity as in the controls. Seemingly, an increased level of CO{sub 2} in air trends to alleviate the impact of the SO{sub 2} at least in the Chinese tung-oil tree. (orig./MG)

  11. To leave or not to leave.

    Science.gov (United States)

    Buchan, James

    2016-06-22

    Lies, damned lies and Brexit statistics. It's not been a good month for anyone espousing evidence-based policy and politics after the chair of the Commons health committee switched from Leave to Remain, citing misuse of data by the Leave campaign. PMID:27332589

  12. The green-leaved variant of Eucalyptus largiflorens: a story involving hybridization and observant local people

    OpenAIRE

    Parsons, Robert F.; Zubrinich, Tatia M.

    2010-01-01

    Eucalyptus largiflorens (Black Box) is the most common tree in the Chowilla anabranch system on the Murray River floodplain. It typically has dull, glaucous, grey-green leaves. Occasional trees with smaller, glossy green leaves (Green Box) occur scattered amongst the Black Box. In areas with increasing salinity, they usually appear much healthier than adjacent, normal Black Box trees. Green Box plants are intermediate between normal Eucalyptus largiflorens plants and Eucalyptus gracilis plant...

  13. 果尔除草剂在阔叶树种育苗中应用试验%The application of oxyfluorfen herbicides in broad leaved tree species seedlings

    Institute of Scientific and Technical Information of China (English)

    王玲

    2014-01-01

    Weeding seeding process is an important link of production, artificial weeding cost high, in the rainy season often form a drunk, to solve this problem, the design of test fruit herbicide concentration, concentration by variance analysis to find out the goal herbicide in the Broadleaved Tree Species Seedlings in the best herbicidal effect. To solve the field in the nursery work weeding problems.%育苗过程中除草是一项重要的生产环节,人工除草成本高,在雨季往往会形成草荒,针对这一难题,此次设计不同浓度的果儿除草剂试验,通过方差分析找出果尔除草剂在阔叶树种育苗过程中最佳除草效果的浓度,以解决在育苗工作中的除草难题。

  14. Leaving home in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard

    2015-01-01

    The paper focuses on ethnic differences in the timing and patterns of leaving the parental home. Leaving home is a key transition in the life course of the individual, and extensive research has been conducted on the timing and patterns of leaving it. However, ethnic differences in these patterns...... of leaving home. Results showed that while some differences disappeared when controlling for covariates, others persisted, thus indicating ethnic differences in home-leaving patterns. A strong link between leaving home and marriage was substantiated for Turks, but not for Somalis. The home......-leaving patterns of Somalis were much more similar to those of Danes. Overall, Turkish descendants were similar to Turkish immigrants but with some differentiation. The analyses identified the existence of ethnic differences in home-leaving patterns but also found evidence of a shift towards less traditional...

  15. Producción de tilapia nilótica (Oreochromis niloticus L. utilizando hojas de chaya (Cnidoscolus chayamansa McVaugh como sustituto parcial del alimento balanceado Nile tilapia production (Oreochromis niloticus L. using tree spinach leaves (Cnidoscolus chayamansa McVaugh as a partial substitute for balanced feed

    Directory of Open Access Journals (Sweden)

    Gaspar R Poot-López

    2012-11-01

    with a limited food supply. In rural areas, the availability of alternative inputs is key to improving fish farming production, especially if these inputs are unprocessed. The leaves of tree spinach (Cnidoscolus chayamansa, a bush that grows in Mexico and Central and South America, are one such option. In this work, juvenile tilapia (7-4.5 g survival, growth rates, and food conversion rates were studied during two seasons (warm and cold, substituting 25 and 50% of the balanced feed rations with raw tree spinach leaves (ad libitum. The experimental design was completely random, with two treatments and one control (00% of the balanced feed ration; three replicates were done in each season. The densities were 36 fish m-per replica in the cold season and 44 fish m-3 per replica in the warm season. The weight gain in the treatments with 50 and 75% balanced feed and tree spinach leaves was similar to that of the control group in both seasons. The cold season adversely affected survival, weight gain, and feed conversion rates in all treatments, but the warm season did not. When tree spinach leaves were included in the tilapia diet, the feed conversion rate for the balanced feed was reduced from 9.7 to 33.62% in the cold season and from 5.38 to 40.23% in the warm season. The results show that the use of locally available complementary inputs such as tree spinach leaves may favor the development of small-scale tilapia cultures in the tropics.

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

    DEFF Research Database (Denmark)

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

    asymptotically optimal and significantly better than other R-tree variants, where a query may visit all N/B leaves in the tree even when T = 0. We also present an extensive experimental study of the practical performance of the PR-tree using both real-life and synthetic data. This study shows that the PR......We present the Priority R-tree, or PR-tree, which is the first R-tree variant that always answers a window query using O((N/B)1 1/d + T/B) I/Os, where N is the number of d-dimensional (hyper-) rectangles stored in the R-tree, B is the disk block size, and T is the output size. This is provably...

  17. Analyzing Coronas of Fruits and Leaves

    OpenAIRE

    Sadikov, Aleksander; Kononenko, Igor; Weibel, Franco

    2004-01-01

    We implemented a system GDV Assistant (Gas Discharge Visualisation Technique) for parameterization and visualization of coronas of humans and plants. Besides standard parameters, developed by the team of Prof. Korotkov, the program includes some additional numerical parameters. In last few years in several studies we recorded coronas of apple tree leaves and fruits in order to verify and compare their vitality under different conditions. We used GDV Assistant for preprocessing and for nu...

  18. Fault trees

    International Nuclear Information System (INIS)

    Fault trees are a method of deductive analysis and a means of graphic representation of the reliability and security of systems. The principles of the method are set out and the main points illustrated by many examples of electrical systems, fluids, and mechanical systems as well as everyday occurrences. In addition, some advice is given on the use of the method

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

    OpenAIRE

    Durzan Don J

    2009-01-01

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

  20. Breakpoint Distance and PQ-Trees

    Science.gov (United States)

    Jiang, Haitao; Chauve, Cedric; Zhu, Binhai

    The PQ-tree is a fundamental data structure that can encode large sets of permutations. It has recently been used in comparative genomics to model ancestral genomes with some uncertainty: given a phylogeny for some species, extant genomes are represented by permutations on the leaves of the tree, and each internal node in the phylogenetic tree represents an extinct ancestral genome, represented by a PQ-tree. An open problem related to this approach is then to quantify the evolution between genomes represented by PQ-trees. In this paper we present results for two problems of PQ-tree comparison motivated by this application. First, we show that the problem of comparing two PQ-trees by computing the minimum breakpoint distance among all pairs of permutations generated respectively by the two considered PQ-trees is NP-complete for unsigned permutations. Next, we consider a generalization of the classical Breakpoint Median problem, where an ancestral genome is represented by a PQ-tree and p permutations are given, with p ≥ 1, and we want to compute a permutation generated by the PQ-tree that minimizes the sum of the breakpoint distances to the p permutations. We show that this problem is Fixed-Parameter Tractable with respect to the breakpoint distance value. This last result applies both on signed and unsigned permutations, and to uni-chromosomal and multi-chromosomal permutations.

  1. 针阔混交林不同演替阶段表层土壤理化性质与优势林木生长的相关性%Correlation between the Growth of Dominant Trees and Surface Soil Physiochemical Properties of Conifer and Broad-Leaved Mixed Forest at Different Succession Stages

    Institute of Scientific and Technical Information of China (English)

    林文树; 穆丹; 王丽平; 邵立郡; 吴金卓

    2016-01-01

    论】毛管孔隙度、速效钾和全磷含量是影响不同演替阶段土壤质量的主要因子;经过不同演替阶段,表层土壤理化性质质量的综合得分表现为中龄林<成熟林<近熟林<老龄林;随着演替进行,针阔混交林的表层土壤理化性质基本呈现质量提高趋势,到老龄林时期达到最佳。本研究得到的不同演替阶段针阔混交林林木生长与表层土壤理化性质特征的相关性为进一步实现该地区森林可持续经营提供了科学依据。%[Objective]This study aims to analyze the relationship between surface soil physiochemical properties and the growth of dominant trees for mixed forest of conifer and broad-leaved species at different succession stages in order to explore the growth patterns of different stands and provide basis for sustainable forest management. [Method]The mixed forest conifers and broad-leaved trees at different succession stages ( middle-aged forest,near-mature forest,mature forest, and old growth forest) in Jiaohe Management Bureau of Forestry Experimental Area,Jilin Province were studied. The methods of comparison and principal component analysis were used to analyze physical and chemical properties of the surface soil,the growth of dominant trees,and the relationship between them.[Result]with the succession of forest,the average diameter at breast height ( DBH) of the dominant tree species increased,the average tree height varied slightly, the regeneration of Pinus koraiensis tended to be stable,and the number of Juglans mandshurica,Ulmus davidiana var. japonica ,and U. macrocarpa gradually decreased in the upper overstory. With respect to the soil physical properties,the soil density was not significantly different among middle-aged forest,near-mature forest and mature forest and it reached the minimum at the stage of old-growth forest. With the succession of forest,the non-capillary porosity gradually decreased and capillary porosity

  2. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  3. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  4. Unimodular Trees versus Einstein Trees

    CERN Document Server

    Alvarez, Enrique; Martin, Carmelo P

    2016-01-01

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

  5. Longevity of guard cell chloroplasts in falling leaves: implication for stomatal function and cellular aging

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, E.; Schwartz, A.

    1982-11-12

    Guard cell chloroplasts in senescing leaves from 12 species of perennial trees and three species of annual plants survived considerably longer than their mesophyll counterparts. In Ginkgo biloba, stomata from yellow leaves opened during the day and closed at night; guard cell chloroplasts from these leaves showed fluorescence transients associated with electron transport and photophosphorylation. These findings indicate that guard cell chloroplasts are highly conserved throughout the life-span of the leaf and that leaves retain stomatal control during senescence.

  6. Neutron radioactivation analysis of plant leaves. What are known from the contents of elements

    International Nuclear Information System (INIS)

    The contents of elements in plants are different according to parts, such as leaves, roots, stems, wooden part and so on. In the case of obtaining the information on the contents of elements in various kinds of plants, it is necessary to select mutually comparable parts. As such comparable parts, leaves which are common in trees and grasses seem useful, but the contents of elements in leaves are possible to change as the age of leaves advances, therefore, attention must be paid to the time of sampling and the age of leaves. It was decided to investigate first how the contents of elements change with the advance of the age of leaves. The objects were American dogwood growing in Kyoto Botanical Garden, and two adjoining trees and one tree at 150 m distance from them were selected. Leaves were sampled from the tree tops and side branches. The analyzed elements were K, Ca, Mg, Fe, Mn, Cu, Zn, B and Al. The contents of elements in leaves varied by seasons, and also the effects according to the parts of sampling and the places of growth were observed. July when leaves are ripe is suitable as the time of sampling leaves. The search for metal deposits by utilizing plants is mentioned. (K.I.)

  7. Combinatorics of distance-based tree inference.

    Science.gov (United States)

    Pardi, Fabio; Gascuel, Olivier

    2012-10-01

    Several popular methods for phylogenetic inference (or hierarchical clustering) are based on a matrix of pairwise distances between taxa (or any kind of objects): The objective is to construct a tree with branch lengths so that the distances between the leaves in that tree are as close as possible to the input distances. If we hold the structure (topology) of the tree fixed, in some relevant cases (e.g., ordinary least squares) the optimal values for the branch lengths can be expressed using simple combinatorial formulae. Here we define a general form for these formulae and show that they all have two desirable properties: First, the common tree reconstruction approaches (least squares, minimum evolution), when used in combination with these formulae, are guaranteed to infer the correct tree when given enough data (consistency); second, the branch lengths of all the simple (nearest neighbor interchange) rearrangements of a tree can be calculated, optimally, in quadratic time in the size of the tree, thus allowing the efficient application of hill climbing heuristics. The study presented here is a continuation of that by Mihaescu and Pachter on branch length estimation [Mihaescu R, Pachter L (2008) Proc Natl Acad Sci USA 105:13206-13211]. The focus here is on the inference of the tree itself and on providing a basis for novel algorithms to reconstruct trees from distances. PMID:23012403

  8. Stability of symplectic leaves

    OpenAIRE

    Crainic, M.; Fernandes, R.L.

    2008-01-01

    We find computable criteria for stability of symplectic leaves of Poisson manifolds. Using Poisson geometry as an inspiration, we also give a general criterion for stability of leaves of Lie algebroids, including singular ones. This not only extends but also provides a new approach (and proofs) to the classical stability results for foliations and group actions.

  9. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    Science.gov (United States)

    Lemessa, Debissa; Hambäck, Peter A; Hylander, Kristoffer

    2015-01-01

    Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests. PMID:25961306

  10. Arthropod but not bird predation in ethiopian homegardens is higher in tree-poor than in tree-rich landscapes.

    Directory of Open Access Journals (Sweden)

    Debissa Lemessa

    Full Text Available Bird and arthropod predation is often associated with natural pest control in agricultural landscapes, but the rates of predation may vary with the amount of tree cover or other environmental factors. We examined bird and arthropod predation in three tree-rich and three tree-poor landscapes across southwestern Ethiopia. Within each landscape we selected three tree-rich and three tree-poor homegardens in which we recorded the number of tree species and tree stems within 100 × 100 m surrounding the central house. To estimate predation rates, we attached plasticine caterpillars on leaves of two coffee and two avocado shrubs in each homegarden, and recorded the number of attacked caterpillars for 7-9 consecutive weeks. The overall mean daily predation rate was 1.45% for birds and 1.60% for arthropods. The rates of arthropod predation varied among landscapes and were higher in tree-poor landscapes. There was no such difference for birds. Within landscapes, predation rates from birds and arthropods did not vary between tree-rich and tree-poor homegardens in either tree-rich or tree-poor landscapes. The most surprising result was the lack of response by birds to tree cover at either spatial scale. Our results suggest that in tree-poor landscapes there are still enough non-crop habitats to support predatory arthropods and birds to deliver strong top-down effect on crop pests.

  11. Men on Parental Leave

    OpenAIRE

    Trutnovská, Aneta

    2014-01-01

    The aim of this thesis is based on the scientific literature related to the topic, and interviews with specific men on parental leave to point out, in particular, on the grounds that affect men, to the decision to become a full-time father, find out how these families work, and also to point out responses or opinions around which these men often encounter. The theoretical part is devoted to male parental leave in terms of its relation to the children, the themes taking on parental leave, the ...

  12. Modular Tree Automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

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

  13. Tree size as a factor influencing leaf emergence and leaf fall in Acacia nigrescens and Combretum apiculatum in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    P. Novellie

    1989-10-01

    Full Text Available In Acacia nigrescens and Combretum apiculatum saplings tended to retain leaves over the dry season, whereas the mature trees generally lost most of their leaves. In Acacia nigrescens the production of new leaves over the dry season was more commonly observed in saplings than in mature trees.

  14. Biomonitoring of air pollution in Prague using tree leaves

    Czech Academy of Sciences Publication Activity Database

    Soudek, Petr; Kinderman, Pavel; Maršík, Petr; Petrová, Šárka; Vaněk, Tomáš

    2012-01-01

    Roč. 10, č. 2 (2012), s. 810-817. ISSN 1459-0255 R&D Projects: GA MŽP(CZ) SP/1B7/129/08 Institutional research plan: CEZ:AV0Z50380511 Keywords : Dust particles * heavy metal * phytoremediation Subject RIV: DI - Air Pollution ; Quality Impact factor: 0.435, year: 2012 http://www.isfae.org/scientficjournal/2012/issue2/pdf/environment/149.pdf

  15. PHARMACOGNOSTICAL EVALUATIONS OF THE LEAVES OF ZIZIPHUS MAURITIANA

    Directory of Open Access Journals (Sweden)

    Ramesh Kumar Singh et al.

    2012-03-01

    Full Text Available Ziziphus mauritiana belongs to family Rhamnaceae and commonly known as Indian jujube or ber. The leaves are alternate and elliptic. Flowers are small and bisexual. The leaves are about 2.5 – 3.2 cm long. Commercially it is cultivated in China & India. Ziziphus mauritiana is small to medium sized spiny tree. The chemical compositions of the leaves are proteins & amino acids, flavonoids, alkaloids, glycosides, terpenoides, saponins, fibers, tannins and phenolic compounds. Leaves are used in the treatment of diarrhoea, gastric disorder, fever, liver damage and pulmonary disorders. The present work deals to summarize the Pharmacognostical studies like ash value, extractive value, moisture content, volatile matters, crude fibers, phytochemical test, fluorescence analysis and micro chemical test. The alcoholic and aqueous extract of Ziziphus mauritiana leave shows hepatoprotective, antioxidant and other important pharmacological activities. The results of above parameters show the clue for more medicinal properties of Ziziphus mauritiana.

  16. Bronchi, Bronchial Tree, & Lungs

    Science.gov (United States)

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

  17. Sofic Tree-Shifts

    OpenAIRE

    Aubrun, Nathalie; Béal, Marie-Pierre

    2013-01-01

    We introduce the notion of sofic tree-shifts which corresponds to symbolic dynamical systems of infinite ranked trees accepted by finite tree automata. We show that, contrary to shifts of infinite sequences, there is no unique reduced deterministic irreducible tree automaton accepting an irreducible sofic tree-shift, but that there is a unique synchronized one, called the Fischer automaton of the tree-shift. We define the notion of almost of finite type tree-shift which are sofic tree-shifts accepted...

  18. Flavonoids from leaves of Mauritia flexuosa

    OpenAIRE

    Djalma M. Oliveira; Ezequias P. Siqueira; Yule R. F. Nunes; Betania B Cota

    2013-01-01

    The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside), kaempferol-3-O-rutinoside (nicotiflorine), quercetin-3-O-rutinoside (rutin), luteolin-8-C-glucoside (orientin) and luteolin-6-C-glucoside (isoorientin). The flavonoids were found out and previously reported as constituents of the ...

  19. Image-Based Modeling of Plants and Trees

    CERN Document Server

    Kang, Sing Bang

    2009-01-01

    Plants and trees are among the most complex natural objects. Much work has been done attempting to model them, with varying degrees of success. In this book, we review the various approaches in computer graphics, which we categorize as rule-based, image-based, and sketch-based methods. We describe our approaches for modeling plants and trees using images. Image-based approaches have the distinct advantage that the resulting model inherits the realistic shape and complexity of a real plant or tree. We use different techniques for modeling plants (with relatively large leaves) and trees (with re

  20. Shapes of tree representations of spin-glass landscapes

    International Nuclear Information System (INIS)

    Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure - a barrier tree - the leaves and internal nodes of which represent, respectively, the local minima and the lowest energy saddles connecting those minima. Here we apply several statistics used in the study of phylogenetic trees to barrier trees that result from the energy landscapes of p-spin models. These statistics give information about the shape of these barrier trees, in particular about balance and symmetry. We then ask if they can be used to classify different types of landscapes, compare them with results obtained from random trees, and investigate the structure of subtrees of the barrier trees. We conclude that at least one of the used statistics is capable of distinguishing different types of landscapes, that the barrier trees from p-spin energy landscapes are quite different from random trees, and that subtrees of barrier trees do not reflect the overall tree structure, but their structure is correlated with their 'depth' in the tree

  1. TRAVEL AND HOME LEAVE

    CERN Multimedia

    Human Resources Division

    2002-01-01

    Administrative procedures for : Travel to the home station and home leave (hl) Additional travel to the home station (at) Travel to the home station and home leave for family reasons (hlf) As part of the process of simplifying administrative procedures, HR and AS Divisions have devised a new, virtually automatic procedure for payment of travel expenses to the home station. The changes are aimed at rationalising administrative procedures and not at reducing benefits. The conditions of eligibility are unchanged. The new procedure, which will be operational with effect from 1st June 2002, will greatly simplify the administrative processing of claims for travel expenses and the recording of home leaves. Currently, requests for payment are introduced manually into the Advances and Claims system (AVCL) by divisional secretariats. All travel to the home station starting prior to 1st June 2002 will be processed according to the existing system whereas that starting on 1st June and after will be processed accordi...

  2. Terpenoid Variations within and among Half-Sibling Avocado Trees, Persea americana Mill. (Lauraceae)

    OpenAIRE

    Niogret, Jerome; Epsky, Nancy D.; Schnell, Raymond J; Boza, Edward J.; Kendra, Paul E.; Heath, Robert R.

    2013-01-01

    Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemical...

  3. Dynamic maceration of Copaifera langsdorffii leaves: a technological study using fractional factorial design

    OpenAIRE

    Ana R. M. Costa-Machado; Jairo K. Bastos; Luís A. P. de Freitas

    2012-01-01

    The Copaifera langsdorffii Desf., Fabaceae, is a Brazilian native tree, known as copaiba, which oil is commonly used in folk medicine as muscle relaxant, wound healing, antiseptic and anti-inflammatory to respiratory and urinary tracts. Despite of the wide use of the oil of Copaifera species, scientific works related to the study of its leaves are rarely found. In fact, processes for flavonoid extraction from C. langsdorffii leaves have not been studied yet leaving a wide field to be investig...

  4. Effect of eucalyptus (Eucalyptus citriodora) fresh or residue leaves on methane emission in vitro

    OpenAIRE

    Adibe L. Abdalla; Mohamed E.A. Nasser; Sobhy M.A. Sallam; Ives C.S. Bueno

    2010-01-01

    Rumen fermentation and methane emission for eucalyptus (Eucalyptus citriodora) fresh leaves (FL) or residue leaves (RL), after essential oil extraction from eucalyptus leaves in comparison with alfalfa (Medicago sativa) hay, were investigated in vitro. Eucalyptus FL and RL were obtained from the Distillery Trees Barras Company, Torrinha City, Sao Paulo, Brazil. The semi-automatic system of gas production was used to measure gas production, methane emission and rumen fermentation after 24 h in...

  5. Morphological variability of leaves of Sorbus torminalis (L.) Crantz in Poland

    OpenAIRE

    Leszek Bednorz

    2011-01-01

    This paper presents the results of the study on morphological variability of leaves of a scattered tree species Sorbus torminalis (L.) Crantz) in Poland. The leaves from short- and long shoots were collected from 17 localities widespread within the range of the species in Poland. Leaves were measured according to 15 morphological traits. The biometric data were subjected to multivariate statistical analysis in attempt to define variability between local populations. Most of the leaf traits ar...

  6. The canary tree

    OpenAIRE

    Mekler, Alan H.; Shelah, Saharon

    1993-01-01

    A canary tree is a tree of cardinality the continuum which has no uncountable branch, but gains a branch whenever a stationary set is destroyed (without adding reals). Canary trees are important in infinitary model theory. The existence of a canary tree is independent of ZFC + GCH.

  7. Healthy,Happy trees

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

  8. Pebbles and Branching Programs for Tree Evaluation

    OpenAIRE

    Cook, Stephen; McKenzie, Pierre; Wehr, Dustin; Braverman, Mark; Santhanam, Rahul

    2010-01-01

    We introduce the Tree Evaluation Problem, show that it is in logDCFL (and hence in P), and study its branching program complexity in the hope of eventually proving a superlogarithmic space lower bound. The input to the problem is a rooted, balanced d-ary tree of height h, whose internal nodes are labeled with d-ary functions on [k] = {1,...,k}, and whose leaves are labeled with elements of [k]. Each node obtains a value in [k] equal to its d-ary function applied to the values of its d childre...

  9. X-tree

    OpenAIRE

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

    2008-01-01

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

  10. TreeDT

    OpenAIRE

    Sevon, Petteri; Toivonen, Hannu; Ollikainen, Vesa

    2006-01-01

    We describe TreeDT, a novel association-based gene mapping method. Given a set of disease-associated haplotypes and a set of control haplotypes, TreeDT predicts likely locations of a disease susceptibility gene. TreeDT extracts, essentially in the form of haplotype trees, information about historical recombinations in the population: A haplotype tree constructed at a given chromosomal location is an estimate of the genealogy of the haplotypes. TreeDT constructs these trees for all locations o...

  11. Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L. to Control Rice Weevil (Sitophilus oryzae L. Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L. en el gorgojo del arroz (Sitophilus oryzae L.

    Directory of Open Access Journals (Sweden)

    Verónica Benzi

    2009-06-01

    Full Text Available Rice weevil (Sitophilus oryzae L. is a primary insect pest of stored grain. The development of resistance resulted in the application of synthetic insecticides. In recent years many plant essential oils have provided potential alternatives to currently used insect control agents. The Brazilian pepper tree (Schinus molle L. var. areira (L. DC. (Anacardiaceae has different biological properties such as insecticidal activity. In this study, repellent, fumigant activity, nutritional indices, and feeding deterrent action were evaluated on S. oryzae adults. Filter paper impregnation was used to test fumigant toxicity, whereas treated whole wheat was used to evaluate repellent activity and a flour disk bioassay was done to evaluate feeding deterrent action and nutritional index alteration. Leaf essential oils showed repellent effects at both concentrations (0.04 and 0.4% w/w, while fruit essential oils lacked repellent activity. Both plant oils altered nutritional indices. Fruit essential oils had a strong feeding deterrent action (62% while leaves had a slight effect (40.6%. With respect to fumigant activity, neither of the essential oils was found to be toxic.El gorgojo del arroz (Sitophilus oryzae. L. es un insecto-plaga de infestación primaria de granos. El uso de insecticidas sintéticos ha desarrollado fenómenos de resistencia. En los últimos años los aceites esenciales se presentan como una alternativa en el control de insectos-plaga. El aguaribay (Schinus molle L. var. areira (L. DC. (Anacardiaceae es una planta con diferentes propiedades biológicas entre las que se destacan el uso como insecticida. El objetivo de este estudio fue evaluar la actividad fumigante, repelente, los índices nutricionales y la actividad antialimentaria de los aceites esenciales de hojas y frutos de S. molle var. areira en adultos de S. oryzae. Para la actividad fumigante se utilizó la técnica de impregnación de papeles de filtro; para la actividad repelente

  12. Leaves: Nature's Solar Collectors

    Science.gov (United States)

    Isabelle, Aaron D.; de Groot, Cornelis

    2009-01-01

    One of the most captivating things about plants is the way they capture the Sun's energy, but this can be a difficult topic to cover with elementary students. Therefore, to help students to make a concrete connection to this abstract concept, this series of solar-energy lessons focuses on leaves and how they act as "solar collectors." As students…

  13. REMINDER: Saved Leave Scheme (SLS)

    CERN Multimedia

    2003-01-01

    Transfer of leave to saved leave accounts Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'* annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that unused leave of all those taking part in the saved leave scheme at the closure of the leave year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2003 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they ar...

  14. Mitragyna speciosa, a psychoactive tree from Southeast Asia with opioid activity.

    Science.gov (United States)

    Adkins, Jessica E; Boyer, Edward W; McCurdy, Christopher R

    2011-01-01

    Mitragyna speciosa Korth. (Rubiaceae) is a tree that is commonly found in Southeast Asia. Leaves from this tree have been traditionally been used for both their stimulant properties as well as an opium substitute. The tree/leaves are currently illegal in four countries, but is currently legal and widely available in the United States. To date over 40 compounds have been isolated from the leaves. The major alkaloid found within the crude extract, mitragynine, has been the subject of many pharmacological studies. In addition to the pharmacological studies, two total syntheses of mitragynine have been published as well as general structure-activity relationships (SARs) with respect to opioid activity. PMID:21050173

  15. TreeRipper web application: towards a fully automated optical tree recognition software

    Science.gov (United States)

    2011-01-01

    Background Relationships between species, genes and genomes have been printed as trees for over a century. Whilst this may have been the best format for exchanging and sharing phylogenetic hypotheses during the 20th century, the worldwide web now provides faster and automated ways of transferring and sharing phylogenetic knowledge. However, novel software is needed to defrost these published phylogenies for the 21st century. Results TreeRipper is a simple website for the fully-automated recognition of multifurcating phylogenetic trees (http://linnaeus.zoology.gla.ac.uk/~jhughes/treeripper/). The program accepts a range of input image formats (PNG, JPG/JPEG or GIF). The underlying command line c++ program follows a number of cleaning steps to detect lines, remove node labels, patch-up broken lines and corners and detect line edges. The edge contour is then determined to detect the branch length, tip label positions and the topology of the tree. Optical Character Recognition (OCR) is used to convert the tip labels into text with the freely available tesseract-ocr software. 32% of images meeting the prerequisites for TreeRipper were successfully recognised, the largest tree had 115 leaves. Conclusions Despite the diversity of ways phylogenies have been illustrated making the design of a fully automated tree recognition software difficult, TreeRipper is a step towards automating the digitization of past phylogenies. We also provide a dataset of 100 tree images and associated tree files for training and/or benchmarking future software. TreeRipper is an open source project licensed under the GNU General Public Licence v3. PMID:21599881

  16. 长白山阔叶红松林中影响乔木幼苗存活的关键因素%Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    应用广义线性混合模型,对长白山阔叶红松林中影响幼苗存活的生物因素和非生物因素进行分析。结果表明:(1)在群落水平上,幼苗存活率和生物因素中同种幼苗邻居显著负相关,说明在阔叶红松林群落中存在负密度制约效应。(2)生物因子和非生物因子对不同年龄阶段的幼苗存活率影响不同。对于1年生的幼苗,幼苗存活率与异种大树邻居呈显著负相关,与同种大树邻居呈显著正相关;对于2—3年生的幼苗,其存活率和同种幼苗邻居、同种大树邻居均呈显著负相关,和非生物因子相关不显著;对于4年生以上的幼苗,其存活率和土壤主成分分析的PC1(低的有机质、速效钾、速效氮等比较贫瘠的土壤)显著负相关。(3)种子的传播方式不同,幼苗存活率的影响因子也不同。对于风传播的物种,存活率与同种幼苗邻居密度显著正相关。对于重力传播的物种,幼苗存活率与土壤PC3(高的全氮和速效氮,含氮较高的土壤)、异种大树邻居、草本密度呈负相关,与林冠开阔度和草本盖度成正相关。(4)对于不同的物种,影响幼苗存活的因素也不同。紫椴的幼苗存活率与土壤PC3、异种大树邻居、草本密度呈显著负相关,与土壤主成分PC2(高的有机质和全氮等养分比较好的土壤)呈显著正相关。%Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100

  17. Effects of biotic and abiotic factors on tree seedling survival in a broad-leaved Korean pine (Pinus koraiensis) mixed forest on Changbai Mountain%长白山阔叶红松林中影响乔木幼苗存活的关键因素

    Institute of Scientific and Technical Information of China (English)

    肖翠; 刘帅; 黄珍; 樊莹; 王均伟; 赵秀海; 唐景毅

    2015-01-01

    Seedling recruitment plays a key role in determining species composition and diversity. Exploring patterns of seedling dynamics can therefore provide crucial insights into the mechanisms that affect seedling recruitment. The broad-leaved Korean pine ( Pinus koraiensis) mixed forest is a temperate forest typical of northeast China. In 2007, we established a 1 hm2 plot in a broad-leaved Korean pine mixed forest on Changbai Mountain, northeast China. We identified, tagged, and mapped each tree with diameter at breast height ≥1 cm. At the same time, we set up 100 seedling quadrats of 1m × 1m which were censused every July. In total, we collected data on 1288 adult trees and 965 seedlings in the 1 hm2 plot between 2012 and 2013, and examined the importance of biotic and abiotic factors on seedling survival using a generalized mixed linear model. Biotic factors included presence of conspecific seedling neighbors and heterospecific seedling neighbors, presence of conspecific adult neighbors and heterospecific adult neighbors, and herb density and herb cover. Abiotic factors included soil organic matter, available soil phosphorus, available soil potassium, available soil nitrogen, total soil nitrogen, and canopy openness. Conspecific neighbors had a significant negative effect on seedling survival at the community level, indicating significant negative density-dependence effects. The effects of biotic and abiotic factors on seedlings differed with seedling age. Conspecific adult neighbors and canopy openness had significant positive effects on survival of, 1-year seedlings while heterospecific adult neighbors had a significant negative effect. In contrast, for 2- to 3-year-old seedlings, conspecific seedling neighbors and conspecific adult neighbors showed a significant negative effect on seedling survival, but abiotic factors had no significant effect. Moreover, for ≥4-year-old seedlings, soil PC axis 1 ( associated with low organic matter available K, available N

  18. Fault tree handbook

    International Nuclear Information System (INIS)

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

  19. Distribution of total nitrogen and N-15 labelled nitrogen applied to apple trees

    International Nuclear Information System (INIS)

    The efficiency of nitrogen fertilization from one year's application was studied in apple trees. Urea enriched with 1,5% N-15 a.e. was applied to 2 years old apple trees. Two irrigation treatments were studied, Al approx. 200mm/week and A2 approx. 100 mm/week. The distribution of N in the different parts of the trees was determined after 2 months of fertilization and after the experimental trees were excavated. The recovery of labelled fertilizer N was different in the trees in both treatments (Al = 1,2% and A2 = 3,1%). However, the distribution in the tree's parts was similar: 46% in leaves, 34% in branches and 20% in roots. We also determined that sampling only 20% of leaves at the beginning and the end of the experiment it is possible to know the quantity of nitrogen from fertilizer, without the excavation trees

  20. Covering tree with stars

    DEFF Research Database (Denmark)

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

    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...

  1. 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...

  2. 增补UV-B辐射下南亚热带森林建群树种叶片对UV-B辐射的防护%UV-B Screening in Leaves of Constructive Tree Species of Low Subtropical Forest under Supplementary UV-B Radiation

    Institute of Scientific and Technical Information of China (English)

    赵平; 孙谷畴; 曾小平

    2008-01-01

    of UV-B radiation absorbing materials, forming a functional protecting screen against UV-B radiation. However, Schima superba and Castanopsi fissa that contained relatively high alkali-extractable cell wall-bound phendics under natural sunlight exhibited a decrease in content of these compounds when exposed to supplementary UV-B radiation, suggesting that under supplementary UV-B radiation the cell wall-phendics in epidermal cell layers might be transformed into soluble compounds in vacuoles where there were lower contents of methanol soluble pigment. This fact assumes that a strategy for protection of photosynthetic apparatus hidden in mesophyll tissue was evolved. Chlorophyll a+b content (μg g-1) was not affected in the needles of P. massoniana and a decrease of 10.7% to 16.8% (mg m-1) occurred in the leaves of the other examined broad-leaved tree species under exposure of supplementary UV-B radiation. Response of carotenoids to supplementary UV-B radiation was variable: The decreased level of carotenoid was observed in C. hystrix and S. superba, and carotenoids were stimulated in P. massoniana, C. chinensis and C. fissa, which might be a functional increase in dissipation of excited energy. The results showed that different acclimation strategies were developed to protect against the increasing UV-B radiation in nature and flavoid screen in the acclimation to UV-B radiation was an important feature of adaptation process in the plants of low subtropical forest. Tab 4, Ref 29

  3. Using FEM to predict tree motion in a wind field

    Institute of Scientific and Technical Information of China (English)

    Xiao-yi HU; Wei-ming TAO; Yi-mu GUO

    2008-01-01

    In this paper we propose a finite element (FE) simulation method to predict tree motion in a wind field. Two FE tree models were investigated: One model was generated based on a realistic nature-looking geometric tree model, and the other was a symmetric model to investigate the influence of asymmetric material properties on tree motion. The vortex-induced vibration (VIV) theory is introduced to estimate the fluctuating wind force being exerted on tree stems and the fluid-structure interaction (FSI) analysis is also included in the simulation. The results indicate that asymmetric material properties result in the crosswind displacement of the investigated node and the main swaying direction deviation. The simulation reveals that under wind loading, a tree with leaves has much larger swaying amplitude along the wind direction and longer swaying period than a tree without leaves.However, the crosswind swaying amplitude is mainly due to branch interaction. The numerical simulation proved that the interaction of tree branches can prevent dangerous swaying motion developing.

  4. The results of fluorescence spectrums of oak and birch leaves investigation from the 30-km influenced zone of Chernobyl NPP

    International Nuclear Information System (INIS)

    The results of a long-term research of laser induced fluorescence of foliage tree' leaves (oak, birch) that grow in different conditions of radioactive pollution (30-km zone of Chernobyl NPP) are presented

  5. Evolution of tree nutrition.

    Science.gov (United States)

    Raven, John A; Andrews, Mitchell

    2010-09-01

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

  6. Fluorescence spectroscopy applied to orange trees

    Science.gov (United States)

    Marcassa, L. G.; Gasparoto, M. C. G.; Belasque, J., Jr.; Lins, E. C.; Dias Nunes, F.; Bagnato, V. S.

    2006-05-01

    In this work, we have applied laser-induced fluorescence spectroscopy to investigate biological processes in orange trees (Citrus aurantium L.). We have chosen to investigate water stress and Citrus Canker, which is a disease caused by the Xanthomonas axonopodis pv. citri bacteria. The fluorescence spectroscopy was investigated by using as an excitation source a 442-nm 15-mW HeCd gas multimode discharge laser and a 532-nm 10-mW Nd3+:YAG laser. The stress manifestation was detected by the variation of fluorescence ratios of the leaves at different wavelengths. The fluorescence ratios present a significant variation, showing the possibility to observe water stress by fluorescence spectrum. The Citrus Canker’s contaminated leaves were discriminated from the healthy leaves using a more complex analysis of the fluorescence spectra. However, we were unable to discriminate it from another disease, and new fluorescence experiments are planned for the future.

  7. REMINDER Saved Leave Scheme (SLS) : Transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2002-01-01

    Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'*) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22B) can be transferred to the saved leave account at the end of the leave year (30 September). We remind you that, since last year, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts is transferred automatically to the saved leave account on that date. Therefore, staff members have no administrative steps to take. In addition, the transfer, which eliminates the risk of omitting to request leave transfers and rules out calculation errors in transfer requests, will be clearly shown in the list of leave transactions that can be consulted in EDH from October 2002 onwards. Furthermore, this automatic leave transfer optimizes staff members' chances of benefiting from a saved leave bonus provided that they are still participants in the schem...

  8. Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2) annual and compensatory leave (excluding saved leave accumulated in accordance with the provisions of Administrative Circular No. 22 B) can be transferred to the saved leave account at the end of the leave year (30 September). Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the ...

  9. Uniform random spanning trees

    OpenAIRE

    Pemantle, Robin

    2004-01-01

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

  10. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  11. Interactive tree of life (iTOL) v3: an online tool for the display and annotation of phylogenetic and other trees

    OpenAIRE

    Letunic, I.; Bork, P.

    2016-01-01

    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. The current version was completely redesigned and rewritten, utilizing current web technologies for speedy and streamlined processing. Numerous new features were introduced and several new data types are now supported. Trees with up to 100,000 leaves can now be efficiently displayed. Full interactive control over pr...

  12. The Wish Tree Project

    Science.gov (United States)

    Brooks, Sarah DeWitt

    2010-01-01

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

  13. 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....

  14. 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...

  15. Litter Supply as a Driver of Microbial Activity and Community Structure on Decomposing Leaves: a Test in Experimental Streams

    OpenAIRE

    Frossard, Aline; Gerull, Linda; Mutz, Michael; Gessner, Mark O.

    2013-01-01

    Succession of newly created landscapes induces profound changes in plant litter supplied to streams. Grasses dominate inputs into open-land streams, whereas tree litter is predominant in forested streams. We set out to elucidate whether the activity and structure of microbial communities on decomposing leaves are determined by litter quality (i.e., grass or tree leaves colonized) or whether changes during riparian succession affecting litter standing stocks on the stream bed play an overridin...

  16. THE COMPARATIVE CHARACTERISTICS CELL OF LEAVES ANATOMY OF MOTOR VEHICLES LOCATION AND LESS POLLUTED IN MAKASSAR CITY INDONESIA

    OpenAIRE

    Tambaru, Elis

    2014-01-01

    This study aims to analyze the characteristics cell of cross-section comparative of leaves anatomy of regreening trees in a motor vehicles location polluted and less polluted. This study used the method of cross-section leaves of five trees species namely: Swietenia macrophylla King; Filicium decipiens (Wigh & Arn) Thwaites; Wodyetia bifurcata Irvine; Polyalthia longifolia Bent & Hook. var. pendula; and Bambusa vulgaris Schrad. var. vitata A & C Rivieria, analysed data by using descriptive. ...

  17. MORPHOLOGICAL ANALYSIS OF THE LEAVES OF Anacardium occidentale L.

    Directory of Open Access Journals (Sweden)

    Glenda Quaresma Ramos

    2016-03-01

    Full Text Available In morphological studies are analyzed various parameters, ranging from macro scale through the micro scale to the nanometer scale, which contribute to the study of taxonomy, pharmacognosy, ecology, among others. Among the structures found in plants, the leaves are most organs analyzed. This study aimed to analyze morphological features of the leaves of the cashew tree, which is a plant of great commercial importance in Brazil. In this work we observed sinuous epidermal cells in the adaxial and abaxial, characterize their stomata in paracytic surrounded subsidiaries cells. On the abaxial surface the presence of glandular trichomes was observed; and cross-sectional analysis showed a single-layered epidermis with compact mesophyll and several layers of parenchyma cells. Keywords: leaf anatomy; cashew tree; optical microscopy.

  18. Flavonoid Contents From Some Exotic Tree Species Growing In Rajasthan Desert

    OpenAIRE

    B.B.S. Kapoor* and Shelja Pandita

    2013-01-01

    Evaluation of flavonoid contents from four selected exotic tree species like Colophospermum mopane, Holopteleaintegrifolia, Kigelia pinnata and Putranjiva roxburghii growing in Rajasthan Desert was carried out. The leaves ofselected trees were analysed for flavonoid contents i.e. Quercetin and Kaempferol. Flavonoid contents likeQuercetin and Kaempferol were isolated and identified. The maximum total flavonoid contents (17.10mg./gdw) wasfound in leaves of Putranjiva roxburghii while minimum (9...

  19. Bioclimate and reproductive potential at the cold limit of European deciduous tree species

    OpenAIRE

    Kollas, Chris

    2013-01-01

    This thesis assessed factors that contribute to the explantion of the upper elevational and latitudinal limits of European broad-leaved tree species by using a set of ecological analysis, including in situ temperature measurements, a transplant experiment and a survey of the reproductive cycle and demography at the species limits. The following key questions were answered in five chapters: Do the elevational thermal limits of broad-leaved tree species correspond to their latitudinal t...

  20. Effects of Ozone and Sulfur Dioxide on Phyllosphere Fungi from Three Tree Species

    OpenAIRE

    Mark E. Fenn; Dunn, Paul H.; Durall, Daniel M.

    1989-01-01

    Short-term effects of ozone (O3) on phyllosphere fungi were studied by examining fungal populations from leaves of giant sequoia (Sequoiadendron giganteum (Lindl.) Buchholz) and California black oak (Quercus kelloggii Newb.). Chronic effects of both O3 and sulfur dioxide (SO2) were studied by isolating fungi from leaves of mature Valencia orange (Citrus sinensis L.) trees. In this chronic-exposure experiment, mature orange trees were fumigated in open-top chambers at the University of Califor...

  1. MEMORY ENHANCING ACTIVITIES OF FICUS RELIGIOSA LEAVES IN RODENTS

    OpenAIRE

    Wangkhem Bandana Devi; Sengottuvelu S.; Haja Shrief S.; Lalitha V; Sivakumar T.

    2011-01-01

    Ficus religiosa, a sacred tree to both Hindus and Buddhists, is recognized for its medicinal as well as religious purposes in India. The ethanolic extract prepared from the leaves of Ficus religiosa was studied for memory enhancing activities in Wistar albino rats and Swiss albino mice. The present study was carried out on five models such as Elevated-Plus Maze, Step through passive avoidance test, Sodium nitrite intoxication, Hebb-Williams Maze and Radial Arm Maze to evaluate learning and me...

  2. Trees in Lhasa

    Institute of Scientific and Technical Information of China (English)

    Degyi

    2008-01-01

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

  3. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

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

  4. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    2014-01-01

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...... and workplace in which they are employed. The paper focuses on fathers’ negotiations of parental leave in three large Danish work places, offering men different opportunities for leave. With a focus on the differences in the work place contexts/opportunities for leave, the aim of the paper is firstly...... to explore men’s negotiations of parental leave at work place level and secondly, to explore and discuss how Danish fathers construct leave practices – and individual male identities – in the workplace....

  5. Negotiating leave in the workplace

    DEFF Research Database (Denmark)

    Bloksgaard, Lotte

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch...... and workplace in which they are employed. The paper focuses on fathers’ negotiations of parental leave in three large Danish work places, offering men different opportunities for leave. With a focus on the differences in the work place contexts/opportunities for leave, the aim of the paper is firstly...... to explore men’s negotiations of parental leave at work place level and secondly, to explore and discuss how Danish fathers construct leave practices – and individual male identities – in the workplace....

  6. Maximum Leaf Spanning Trees of Growing Sierpinski Networks Models

    CERN Document Server

    Yao, Bing; Xu, Jin

    2016-01-01

    The dynamical phenomena of complex networks are very difficult to predict from local information due to the rich microstructures and corresponding complex dynamics. On the other hands, it is a horrible job to compute some stochastic parameters of a large network having thousand and thousand nodes. We design several recursive algorithms for finding spanning trees having maximal leaves (MLS-trees) in investigation of topological structures of Sierpinski growing network models, and use MLS-trees to determine the kernels, dominating and balanced sets of the models. We propose a new stochastic method for the models, called the edge-cumulative distribution, and show that it obeys a power law distribution.

  7. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

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

  8. Making the National Adaptation Programme of Action (NAPA) More Responsive to the Livelihood Needs of Tree Planting Farmers, Drawing on Previous Experience in Dryland Sudan

    OpenAIRE

    Markku Kanninen; Olavi Luukkanen; Fobissie Blese Kalame

    2011-01-01

    Recently, tree planting has become popular under NAPA. For decades, many tree planting projects were implemented to reduce the vulnerability of ecosystems and societies. Despite all of these, tree-dependent livelihoods remain vulnerable, which leaves doubt on the benefit of tree planting to enhance the resilience of livelihoods to climatic shocks. This suggests that much can be learned from the past to improve future tree planting adaptation projects. This paper draws on the experience of far...

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

    OpenAIRE

    Zhang, Louxin

    2010-01-01

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

  10. Quantitative Analysis of Tree Species Diversity in Different Oak (Quercus spp.) Dominated Forests in Garhwal Himalaya, India

    OpenAIRE

    Gajendra SINGH; Gopal S. RAWAT

    2012-01-01

    Himalayan broad-leaved forests are mainly dominated by oak (Quercus spp.) species. Oak species with other tree species provide numerous ecosystem services and serve as lifeline for local inhabitants. Overall tree diversity and their status in different oak dominated forests viz., Quercus leucotrichophora (1500-2200 m), Q. floribunda (2201-2700 m) and Q. semecarpifolia (2701-3300 m) were studied in Garhwal, Himalaya. A total of 54 tree species (40 genera) in Q. leucotrichophora, 43 tree specie...

  11. Green leaves as indicator for air pollution

    International Nuclear Information System (INIS)

    Green leaves of Ficus (Ficus penegalensis) and Neem (Azadirachta indica) were analyzed for their trace metals (Pb, Zn and Cd) contents. The samples were collected and washed according to metal analysis standardization. Solutions of the samples for analysis were obtained by wet-digestion method using nitric perchloric acid mixture. The trace elements lead, zinc and cadmium were determined by Atomic Absorption Spectroscopic technique (AAS) for the 18 samples collected from Khartoum (Sharia elneel), Omdurman (Ombadda) and Khartoum North (Kadaro) as heavy-traffic, low-traffic areas and distal area, respectively. The species Ficus and Neem samples were collected each randomly from such areas. The samples were taken from the tips, mids and bottoms of each tree. (Author)

  12. Detection of heavy metals in leaves of melia azedarach and eucalyptus citriodora as biomonitring tools in the region of Quetta valley

    International Nuclear Information System (INIS)

    The concentrations of heavy metals viz., Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in leaves of two tree species, Melia azedarach and Eucalyptus citriodora (Safeda) from different sampling sites at urban areas in Quetta city , were measured. Correlation between elements and the use of tree leaves as indicators of environmental pollution was investigated. The results show that the higher concentrations of heavy metals in Eucalyptus leaves of the areas of the Hudda, Barori and Mashraqi by Pass and in the areas with dense transportation activities are in function. So this preliminary study presents scientific basis to establish the applicability of the tree leaves as bio-monitoring tool for the rapid evaluation of the pollution status in the Quetta city by analyzing heavy metals concentration in the tree leaves. (author)

  13. Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance

    DEFF Research Database (Denmark)

    Liesche, Johannes; Windt, Carel; Bohr, Tomas;

    2015-01-01

    In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, sha...

  14. Water isotopologues in leaves

    Science.gov (United States)

    Cuntz, M.; Ogée, J.; Farquhar, G. D.; Cernusak, L. A.; Peylin, P.; Bariac, T.

    2007-12-01

    Leaf water isotope enrichment is a cornerstone of a variety of isotopic applications. It imprints on different substances such as atmospheric CO2, O2, and plant organic matter. But different applications use enrichment in different parts of the leaf and weighted by different fluxes. For example, leaf organic matter is determined by the assimilation-weighted average bulk water enrichment. Atmospheric CO2 and O2 are determined by the enrichment near the evaporating sites, either weighted by the one-way CO2 flux from the stomata to the atmosphere or by electron transport, resp. These applications of leaf water enrichment are used from the leaf level up to global scales. It is therefore essential to understand the time course of leaf water enrichment at both the evaporating sites and in the mesophyll but also to asses the suitability of simple models such as the Craig & Gordon (1965) steady-state prediction or the Dongmann et al. (1974) non-steady-state model. We describe here advection and diffusion of water isotopologues in leaves in the non-steady state. We first show how this relates to earlier non-steady state bulk leaf water enrichment models. The adv.-diff. model compares very well with observations of bulk mesophyll water during the whole diel cycle. It compares well with the enrichment at the evaporative sites during the day but shows some deviations at night. It is clear that night-time stomatal conductance should be measured in the future. However, varying mesophyll water volume did not seem critical for a good prediction. In addition, observations of single diurnal cycles do not constrain the effective length in the mesophyll. Finally, we show when simpler models of leaf water enrichment are suitable for applications of leaf water isotopes once weighted with the appropriate gas exchange flux. We then present a two-dimensional adv.-diff. description of leaf water enrichment along monocot leaves. The model reproduces well all published measurements along

  15. Further analysis on the total number of subtrees of trees

    CERN Document Server

    Li, Shuchao

    2012-01-01

    We study that over some types of trees with a given number of vertices, which trees minimize or maximize the total number of subtrees. Trees minimizing (resp. maximizing) the total number of subtrees usually maximize (resp. minimize) the Wiener index, and vice versa. Here are some of our results: (1) Let $\\mathscr{T}_n^k$ be the set of all $n$-vertex trees with $k$ leaves, we determine the maximum (resp. minimum) value of the total number of subtrees of trees among $\\mathscr{T}_n^k$ and characterize the extremal graphs. (2) Let $\\mathscr{P}_n^{p,q}$ be the set of all $n$-vertex trees, each of which has a $(p,q)$-bipartition, we determine the maximum (resp. minimum) value of the total number of subtrees of trees among $\\mathscr{P}_n^{p,q}$ and characterize the extremal graphs. (3) Let $\\mathscr{A}_n^q$ be the set of all $q$-ary trees with $n$ non-leaf vertices, we determine the minimum value of the total number of subtrees of trees among $\\mathscr{A}_n^q$ and identify the extremal graph.

  16. A Beta-splitting model for evolutionary trees.

    Science.gov (United States)

    Sainudiin, Raazesh; Véber, Amandine

    2016-05-01

    In this article, we construct a generalization of the Blum-François Beta-splitting model for evolutionary trees, which was itself inspired by Aldous' Beta-splitting model on cladograms. The novelty of our approach allows for asymmetric shares of diversification rates (or diversification 'potential') between two sister species in an evolutionarily interpretable manner, as well as the addition of extinction to the model in a natural way. We describe the incremental evolutionary construction of a tree with n leaves by splitting or freezing extant lineages through the generating, organizing and deleting processes. We then give the probability of any (binary rooted) tree under this model with no extinction, at several resolutions: ranked planar trees giving asymmetric roles to the first and second offspring species of a given species and keeping track of the order of the speciation events occurring during the creation of the tree, unranked planar trees, ranked non-planar trees and finally (unranked non-planar) trees. We also describe a continuous-time equivalent of the generating, organizing and deleting processes where tree topology and branch lengths are jointly modelled and provide code in SageMath/Python for these algorithms. PMID:27293780

  17. A Beta-splitting model for evolutionary trees

    Science.gov (United States)

    Sainudiin, Raazesh

    2016-01-01

    In this article, we construct a generalization of the Blum–François Beta-splitting model for evolutionary trees, which was itself inspired by Aldous' Beta-splitting model on cladograms. The novelty of our approach allows for asymmetric shares of diversification rates (or diversification ‘potential’) between two sister species in an evolutionarily interpretable manner, as well as the addition of extinction to the model in a natural way. We describe the incremental evolutionary construction of a tree with n leaves by splitting or freezing extant lineages through the generating, organizing and deleting processes. We then give the probability of any (binary rooted) tree under this model with no extinction, at several resolutions: ranked planar trees giving asymmetric roles to the first and second offspring species of a given species and keeping track of the order of the speciation events occurring during the creation of the tree, unranked planar trees, ranked non-planar trees and finally (unranked non-planar) trees. We also describe a continuous-time equivalent of the generating, organizing and deleting processes where tree topology and branch lengths are jointly modelled and provide code in SageMath/Python for these algorithms. PMID:27293780

  18. A Quadratic Time Algorithm for Computing the Quartet Distance between Two General Trees

    DEFF Research Database (Denmark)

    Mailund, Thomas; Nielsen, Jesper; Pedersen, Christian Storm

    2009-01-01

    We derive a quadratic time and space algorithm for computing the quartet distance between a pair of general trees, i.e. trees where inner nodes can have any degreeges3. The time and space complexity of our algorithm is quadratic in the number of leaves and does not depend on the degree of the inner...... nodes. This makes it the fastest algorithm for computing the quartet distance between general trees independent of the degree of the inner nodes....

  19. Multiscale model of a freeze-thaw process for tree sap exudation

    OpenAIRE

    Graf, Isabell; Ceseri, Maurizio; Stockie, John M.

    2015-01-01

    Sap transport in trees has long fascinated scientists, and a vast literature exists on experimental and modelling studies of trees during the growing season when large negative stem pressures are generated by transpiration from leaves. Much less attention has been paid to winter months when trees are largely dormant but nonetheless continue to exhibit interesting flow behaviour. A prime example is sap exudation, which refers to the peculiar ability of sugar maple (Acer saccharum) and related ...

  20. Functional traits of trees and effects on soil functions and ecosystem services

    OpenAIRE

    Marañón, Teodoro; Navarro-Fernández, Carmen M.; María T. Domínguez; Madejón, Paula; Murillo, José M.

    2015-01-01

    Tree-soil interactions are complex and depend on the site conditions. The functional diversity of trees will affect differently the soil functions and ecosystem services. Here we present results from the Guadiamar Green Corridor (Sevilla, Spain). A former cropland was affected by a mine-spill (in 1998), then the soil was cleaned-up, remediated and afforested with several native shrub and tree species. In 2014 we studied functional traits of leaves and roots in seven of the affo...

  1. Frost hardiness in walnut trees (Juglans regia L.): How to link physiology and modelling?

    OpenAIRE

    Charrier, Guillaume; Poirier, Magalie; Bonhomme, Marc; Lacointe, André; Ameglio, Thierry,

    2013-01-01

    In the literature, frost hardiness (FH) studies in trees have often been restricted to one organ (buds, leaves, needles or twigs). To extend our knowledge and gain a unified view, FH differences between organs and tissues or throughout the life of the tree have to be characterized in relation to physiological changes. In this study, different organs and tissues of young potted and mature orchard walnut trees (Juglans regia L.) were compared for seasonal changes in FH during different years. F...

  2. Theoretical and experimental determination of phloem translocation speeds in gymnosperm and angiosperm trees

    DEFF Research Database (Denmark)

    Liesche, Johannes; Jensen, K.; Minchin, P.; Bohr, Tomas; Schulz, Alexander

    2013-01-01

    In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Carbohydrate translocation in the phloem is a fundamental aspect of tree physiology with relevance for tree...... crop performance and climate change. In this paper, we present theoretical and experimental data on the carbohydrate transport speed inside the phloem....

  3. Spot Anthracnose Disease Caused by Colletotrichum gloeosporioides on Tulip Tree in Korea

    OpenAIRE

    Choi, Okryun; Choi, Okhee; Kwak, Youn-Sig; Kim, Jinwoo; Kwon, Jin-Hyeuk

    2012-01-01

    The tulip tree (Liriodendron chinense) has been widely cultivated in Korea as a street or garden tree for its large flowers, which have a superficial resemblance to tulips. Occurrence of anthracnose disease on the leaves of tulip trees growing on the campus of Gyeongsang National University, Jinju, Korea, has been observed. Based on mycological characteristics, pathogenicity, and internal transcribed spacer sequence, the causal fungus was identified as Colletotrichum gloeosporioides. This is ...

  4. Electrical signaling, stomatal conductance, ABA and Ethylene content in avocado trees in response to root hypoxia

    OpenAIRE

    Pilar M Gil; Gurovich, Luis; Schaffer, Bruce; García, Nicolás; Iturriaga, Rodrigo

    2009-01-01

    Avocado (Persea americana Mill.) trees are among the most sensitive of fruit tree species to root hypoxia as a result of flooded or poorly drained soil. Similar to drought stress, an early physiological response to root hypoxia in avocado is a reduction of stomatal conductance. It has been previously determined in avocado trees that an extracellular electrical signal between the base of stem and leaves is produced and related to reductions in stomatal conductance in response to drought stress...

  5. Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

    International Nuclear Information System (INIS)

    The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The Sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO42-. It can monitor the sulfur pollution in atmosphere. (authors)

  6. Determination of some tree parameters using terrestrial laser scanner in urban green areas

    Directory of Open Access Journals (Sweden)

    Mustafa Akgül

    2016-07-01

    Full Text Available The aim of this study is to measure the parameters for modelling individual and street trees in urban areas using Terrestrial Laser Scanner (TLS data. Breast height diameter (d1.30, tree height, crown base height, distance between trees were measured in the roadside trees which are composed of Narrow-leaved ash (Fraxinus angustifolia Vahl. in Istanbul University Faculty of Forestry Campus. In addition, tree zone models of the trees were formed in order to express development process of trees with time in an integrated way and to make connections among different parts of trees. As a result of measurements, d1.30valuesvaried between 24 cm and 45,6 cm both from ground measurement and TLS. Statistically there were not a significant difference between d1.30 values, even though ground measurement values were higher than TLS measurements. According to regression analysis, a significant correlation was found between ground and TLS mesurements (R2=0,971, p<0,05. Objective values were derived from TLS data related to tree crown forms, tree zone model and tree architecture. The ratio of static and dynamic mass of trees and their relations were showed on 3D tree models. 3D tree models and measurements on this models, which were carried out in this study, can be used in maintenance and pruning application of individual and forests of Urban areas.

  7. Trees in renorming theory

    OpenAIRE

    Haydon, Richard

    1995-01-01

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

  8. Annotated Stack Trees

    OpenAIRE

    Hague, Matthew; Penelle, Vincent

    2015-01-01

    Annotated pushdown automata provide an automaton model of higher-order recursion schemes, which may in turn be used to model higher-order programs for the purposes of verification. We study Ground Annotated Stack Tree Rewrite Systems -- a tree rewrite system where each node is labelled by the configuration of an annotated pushdown automaton. This allows the modelling of fork and join constructs in higher-order programs and is a generalisation of higher-order stack trees recently introduced by...

  9. From Fields to Trees

    OpenAIRE

    Hamze, Firas; De Freitas, Nando

    2012-01-01

    We present new MCMC algorithms for computing the posterior distributions and expectations of the unknown variables in undirected graphical models with regular structure. For demonstration purposes, we focus on Markov Random Fields (MRFs). By partitioning the MRFs into non-overlapping trees, it is possible to compute the posterior distribution of a particular tree exactly by conditioning on the remaining tree. These exact solutions allow us to construct efficient blocked and Rao-Blackwellised ...

  10. 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.

  11. Generalized Binomial Trees

    OpenAIRE

    Jackwerth, Jens Carsten

    1996-01-01

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

  12. [Applicability analysis of spatially explicit model of leaf litter in evergreen broad-leaved forests].

    Science.gov (United States)

    Zhao, Qing-Qing; Liu, He-Ming; Jonard, Mathieu; Wang, Zhang-Hua; Wang, Xi-Hua

    2014-11-01

    The spatially explicit model of leaf litter can help to understand its dispersal process, which is very important to predict the distribution pattern of leaves on the surface of the earth. In this paper, the spatially explicit model of leaf litter was developed for 20 tree species using litter trap data from the mapped forest plot in an evergreen broad-leaved forest in Tiantong, Zhejiang Pro- vince, eastern China. Applicability of the model was analyzed. The model assumed an allometric equation between diameter at breast height (DBH) and leaf litter amount, and the leaf litter declined exponentially with the distance. Model parameters were estimated by the maximum likelihood method. Results showed that the predicted and measured leaf litter amounts were significantly correlated, but the prediction accuracies varied widely for the different tree species, averaging at 49.3% and ranging from 16.0% and 74.0%. Model qualities of tree species significantly correlated with the standard deviations of the leaf litter amount per trap, DBH of the tree species and the average leaf dry mass of tree species. There were several ways to improve the forecast precision of the model, such as installing the litterfall traps according to the distribution of the tree to cover the different classes of the DBH and distance apart from the parent trees, determining the optimal dispersal function of each tree species, and optimizing the existing dispersal function. PMID:25898606

  13. IMPACT OF Global Warming on Trees

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-30

    trees have been found to dry from top to bottom in all the known cases in Pakistan. As the water stops reaching top branches due to insect attack at tree-ground interface or reduced water table or both the tree leaves start drying from the top.

  14. Parental Leave Policies and Parents' Employment and Leave-Taking

    Science.gov (United States)

    Han, Wen-Jui; Ruhm, Christopher; Waldfogel, Jane

    2009-01-01

    We describe trends in maternal employment and leave-taking after birth of a newborn and analyze the extent to which these behaviors are influenced by parental leave policies. Data are from the June Current Population Survey (CPS) Fertility Supplements, merged with other months of the CPS, and cover the period 1987 to 1994. This time span is one…

  15. The tree BVOC index

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

  16. Symmetric M-tree

    CERN Document Server

    Sexton, Alan P

    2010-01-01

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

  17. The tree BVOC index

    International Nuclear Information System (INIS)

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

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

    NARCIS (Netherlands)

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

    1996-01-01

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

  19. Characterization of fatty alcohol and sterol fractions in olive tree.

    Science.gov (United States)

    Orozco-Solano, Mara; Ruiz-Jimenez, José; Luque De Castro, María D

    2010-07-14

    The determination of sterols and fatty alcohols is a part of the study of the metabolomic profile of the unsaponifiable fraction in olive tree. Leaves and drupes from three varieties of olive tree (Arbequina, Picual, and Manzanilla) were used. The content of the target compounds was studied in five ripeness stages and three harvesting periods for olive drupes and leaves, respectively. A method based on ultrasound-assisted extraction and derivatization for the individual identification and quantitation of sterols and fatty alcohols, involving chromatographic separation and mass spectrometry detection by selected ion monitoring, was used. The concentrations of alcohols and sterols in the drupes ranged between 0.1 and 1086.9 mug/g and between 0.1 and 5855.3 mug/g, respectively, which are higher than in leaves. Statistical studies were developed to show the relationship between the concentration of the target analytes and variety, ripeness stage, and harvesting period. PMID:20550122

  20. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae).

    Science.gov (United States)

    Niogret, Jerome; Epsky, Nancy D; Schnell, Raymond J; Boza, Edward J; Kendra, Paul E; Heath, Robert R

    2013-01-01

    Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's) determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees. PMID:24039994

  1. Terpenoid variations within and among half-sibling avocado trees, Persea americana Mill. (Lauraceae.

    Directory of Open Access Journals (Sweden)

    Jerome Niogret

    Full Text Available Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae. The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedlings initiated from a single maternal tree. Two-way analysis of variance was conducted on 34 chemicals that comprised at least 3% of the total chemical content of at least one tree and/or location within a tree. There were significant interactions between genotype and location sampled for most chemicals. Parentage analysis using microsatellite molecular markers (SSR's determined that the four trees had three fathers and that they represented two full-siblings and two half-sibling trees. Descriptive discriminant analysis found that both genotype and location within a tree could be separated based on chemical content, and that the chemical content from full-siblings tended to be more similar than chemical content from half-siblings. To further explore the relationship between genetic background and chemical content, samples were analyzed from leaf material from 20 trees that included two sets of full-sibling seedling trees, the maternal tree and the surviving paternal tree. Descriptive discriminant analysis found good separation between the two full-sibling groups, and that the separation was associated with chemistry of the parental trees. Six groups of chemicals were identified that explained the variation among the trees. We discuss the results in relation to the discrimination process used by wood-boring insects for site-selection on host trees, for tree selection among potential host trees, and the potential use of terpenoid chemical content in chemotaxonomy of avocado trees.

  2. Starch metabolism in leaves.

    Science.gov (United States)

    Orzechowski, Sławomir

    2008-01-01

    Starch is the most abundant storage carbohydrate produced in plants. The initiation of transitory starch synthesis and degradation in plastids depends mainly on diurnal cycle, post-translational regulation of enzyme activity and starch phosphorylation. For the proper structure of starch granule the activities of all starch synthase isoenzymes, branching enzymes and debranching enzymes are needed. The intensity of starch biosynthesis depends mainly on the activity of AGPase (adenosine 5'-diphosphate glucose pyrophosphorylase). The key enzymes in starch degradation are beta-amylase, isoamylase 3 and disproportionating enzyme. However, it should be underlined that there are some crucial differences in starch metabolism between heterotrophic and autotrophic tissues, e.g. is the ability to build multiprotein complexes responsible for biosynthesis and degradation of starch granules in chloroplasts. The observed huge progress in understanding of starch metabolism was possible mainly due to analyses of the complete Arabidopsis and rice genomes and of numerous mutants with altered starch metabolism in leaves. The aim of this paper is to review current knowledge on transient starch metabolism in higher plants. PMID:18787712

  3. Flavonoids from the leaves of Iranian Linden; Tilia rubra subsp. caucasica

    OpenAIRE

    M.R. Delnavazi; M. Shahabi; N. Yassa

    2015-01-01

    Background and objectives: Plants belonging to the genus Tilia L. (Tiliaceae) are often tall beautiful trees which are considered for various medicinal potentials of their flowers and leaves. The present study was an attempt to investigate the phytochemical constituents of Tilia rubra subsp. caucasica leaves from the hyrcanian forests of north of Iran. Methods: Chromatography on Silica gel (normal and reversed-phase) and Sephadex LH20 was applied for isolation and purification of the compound...

  4. Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Fo rest

    Institute of Scientific and Technical Information of China (English)

    WenYuanguang; LiuShirong; ChenFang; HeTatping; LiangHongwen

    2005-01-01

    Evergreen broad-leaved forest is one of the most important vegetation types in China. Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China.tn this paper, the tendency and rate of species diversity restoration of the evergreen broad-lea ved forest in Darning Mountain has been studied. The main results are as follows:(a) in subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forest can be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad-leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest 178 species appeared in a 60Om2, sample area after 20 years"" natural recovering. Among these species, 58 were tree layer and the height of community reached 18m, The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of light demanding broad-leaved pioneer trees and rain-tolerance broad-leaved trees, and it need another 40-80 years to reach the stage consisting of min-tulerance evergreen broad-leaved trees, (c) Species number increased quickly at the early stage (2-20 years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years ), then maintained a relatively stable level at the late-stage (over 150 years).

  5. REMINDER Saved Leave Scheme (SLS) : Simplified procedure for the transfer of leave to saved leave accounts

    CERN Multimedia

    HR Division

    2001-01-01

    As part of the process of streamlining procedures, the HR and AS Divisions have jointly developed a system whereby annual and compensatory leave will henceforth be automatically transferred1) to saved leave accounts. Under the provisions of the voluntary saved leave scheme (SLS), a maximum total of 10 days'2)Previously, every person taking part in the scheme has been individually issued with a form for the purposes of requesting the transfer of leave to the leave account and the transfer has then had to be done manually by HR Division. To streamline the procedure, unused leave of all those taking part in the saved leave scheme at the closure of the leave-year accounts will henceforth be transferred automatically to the saved leave account on that date. This simplification is in the interest of all parties concerned. This automatic transfer procedure has a number of advantages for participants in the SLS scheme. First, staff members will no longer have to take any administrative steps. Secondly, the new proced...

  6. Direct and indirect contamination of tree crops with Cs-134

    International Nuclear Information System (INIS)

    A long term glasshouse pot experiment was established in 1994 to study the transfer factors of Cs-134 from soil to olive and orange trees for which no relevant data are available. A calcareous-heavy textured and an acid-light textured soil were used in this experiment. Results from two year's experimentation are considered in this study. The ability of the studied plant species for Cs-134 root uptake seems to be significantly influenced by soil type. The contamination of both tree species grown on calcareous and heavy soil was very low and did not change much with the time. On the contrary, trees grown on acid and light soil showed much higher Cs-134 concentration (up to 34 times for orange and 23 for olive trees) which significantly increased with the time. Both olive and orange trees showed a similar behaviour in the studied soils. Effort was also made to study the long term consequences of the direct contamination in a field experiment where an olive tree was contaminated by dry deposition with Cs-134. Six months after contamination 5 % of the Cs-134 deposited on the leaves was measured in the first olive production. However, very small quantities (= 0.5 %) of the olive Cs-134 was detected in the unprocessed olive oil. The following year 15 % of the Cs-134 remained in the leaves while extremely low quantities of Cs-134 were detected in either olives or olive oil. (author)

  7. 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...

  8. Searching informed game trees

    NARCIS (Netherlands)

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

    1992-01-01

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

  9. Pruning peach trees

    OpenAIRE

    Sagers, Larry A.

    1988-01-01

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

  10. The arithmetic of trees

    OpenAIRE

    Bruno, Adriano; Yasaki, Dan

    2008-01-01

    The arithmetic of the natural numbers can be extended to arithmetic operations on planar binary trees. This gives rise to a non-commutative arithmetic theory. In this exposition, we describe this arithmetree, first defined by Loday, and investigate prime trees.

  11. Tree damage and mycotrophy

    Energy Technology Data Exchange (ETDEWEB)

    Heyser, W.; Iken, J.; Meyer, F.H.

    1988-10-22

    Tree species that are particularly endangered in our forests are characterized by the fact that they live in an obligatory symbiosis with ectomycorrhiza fungii. In verifying which tree species appear to be more damaged or less severely damaged, a conspicuous phenomenon noted was that the tree species exhibiting slight symptoms of damage or none at all included such ones as form mycorrhizas facultatively or dispense with mycorrhizas, e.g. Acer, Aesculus, Fraxinus, Populus, Salix. Given that trees in municipal gardens reflect the development and extent of damage in a way similar to forests, and given also that much greater numbers of tree species are often cultured in parks of this type, the latter were considered particularly suited to examine the question of whether a relationship exists between mycotrophy and the severity of damage.

  12. Pebbles and Branching Programs for Tree Evaluation

    CERN Document Server

    Cook, Stephen; Wehr, Dustin; Braverman, Mark; Santhanam, Rahul

    2010-01-01

    We introduce the Tree Evaluation Problem, show that it is in logDCFL (and hence in P), and study its branching program complexity in the hope of eventually proving a superlogarithmic space lower bound. The input to the problem is a rooted, balanced d-ary tree of height h, whose internal nodes are labeled with d-ary functions on [k] = {1,...,k}, and whose leaves are labeled with elements of [k]. Each node obtains a value in [k] equal to its d-ary function applied to the values of its d children. The output is the value of the root. We show that the standard black pebbling algorithm applied to the binary tree of height h yields a deterministic k-way branching program with Theta(k^h) states solving this problem, and we prove that this upper bound is tight for h=2 and h=3. We introduce a simple semantic restriction called "thrifty" on k-way branching programs solving tree evaluation problems and show that the same state bound of Theta(k^h) is tight (up to a constant factor) for all h >= 2 for deterministic thrift...

  13. Accessibility percolation on n-trees

    OpenAIRE

    Nowak, Stefan; Krug, Joachim

    2013-01-01

    Accessibility percolation is a new type of percolation problem inspired by evolutionary biology. To each vertex of a graph a random number is assigned and a path through the graph is called accessible if all numbers along the path are in ascending order. For the case when the random variables are independent and identically distributed, we derive an asymptotically exact expression for the probability that there is at least one accessible path from the root to the leaves in an $n$-tree. This p...

  14. Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L.) to Control Rice Weevil (Sitophilus oryzae L.) Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L.) en el gorgojo del arroz (Sitophilus oryzae L.)

    OpenAIRE

    Verónica Benzi; Natalia Stefanazzi; Adriana A. Ferrero

    2009-01-01

    Rice weevil (Sitophilus oryzae L.) is a primary insect pest of stored grain. The development of resistance resulted in the application of synthetic insecticides. In recent years many plant essential oils have provided potential alternatives to currently used insect control agents. The Brazilian pepper tree (Schinus molle L. var. areira (L.) DC.) (Anacardiaceae) has different biological properties such as insecticidal activity. In this study, repellent, fumigant activity, nutritional indices, ...

  15. A sub-cubic time algorithm for computing the quartet distance between two general trees

    DEFF Research Database (Denmark)

    Nielsen, Jesper; Kristensen, Anders Kabell; Mailund, Thomas;

    2011-01-01

    derived a new algorithm for computing the quartet distance between a pair of general trees, i.e. trees where inner nodes can have any degree ≥ 3. The time and space complexity of our algorithm is sub-cubic in the number of leaves and does not depend on the degree of the inner nodes. This makes it the...... fastest algorithm so far for computing the quartet distance between general trees independent of the degree of the inner nodes. Conclusions We have implemented our algorithm and two of the best competitors. Our new algorithm is significantly faster than the competition and seems to run in close to......Background When inferring phylogenetic trees different algorithms may give different trees. To study such effects a measure for the distance between two trees is useful. Quartet distance is one such measure, and is the number of quartet topologies that differ between two trees. Results We have...

  16. PhySortR: a fast, flexible tool for sorting phylogenetic trees in R

    Science.gov (United States)

    Stephens, Timothy G.; Bhattacharya, Debashish; Ragan, Mark A.

    2016-01-01

    A frequent bottleneck in interpreting phylogenomic output is the need to screen often thousands of trees for features of interest, particularly robust clades of specific taxa, as evidence of monophyletic relationship and/or reticulated evolution. Here we present PhySortR, a fast, flexible R package for classifying phylogenetic trees. Unlike existing utilities, PhySortR allows for identification of both exclusive and non-exclusive clades uniting the target taxa based on tip labels (i.e., leaves) on a tree, with customisable options to assess clades within the context of the whole tree. Using simulated and empirical datasets, we demonstrate the potential and scalability of PhySortR in analysis of thousands of phylogenetic trees without a priori assumption of tree-rooting, and in yielding readily interpretable trees that unambiguously satisfy the query. PhySortR is a command-line tool that is freely available and easily automatable. PMID:27190724

  17. Cellulosic and hemicellulosic fractions dosage of Pistacia atlantica Desf. subsp. atlantica leaves in western Algeria.

    Science.gov (United States)

    A, El Zerey-Belaskri; Benhassaini, H; Naimi, W; Rahoui, S

    2013-01-01

    The aim of this study was to valorise a deciduous tree called Pistacia atlantica. Cell wall polysaccharides (cellulose and hemicelluloses) were isolated and dosed from mature and young pistachio leaves. The samples were collected from six different locations in the Sidi Bel Abbes region (western Algeria). The wall residue yield varied from 39.06% to 69.5%.The cellulose and the hemicellulose's cell wall yield varied from 21.25% to 40.6% and from 0.11% to 13.6%, respectively [corrected]. In the mature leaves, the cellulosic fraction is more important than the hemicellulosic fraction. The highest yield is noted in the young leaves. PMID:23323625

  18. New statement of leave format

    CERN Multimedia

    HR Department

    2009-01-01

    Following the communication of the Standing Concertation Committee published in Weekly Bulletin No. 18-19 of 27 April 2009, the current statement of leave on monthly pay slips has been replaced with the EDH Leave Transactions report that displays the up-to-date situation of individual leave balances at all times. The report is available on EDH. Additionally, the layout of the pay slip has been modernised. The new version of the pay slip will be send out from September 2009 onwards. Finance and Purchasing Department, Personnel Accounting Human Resources Department, Organisation and Procedures General Infrastructure Services Department, Administrative Information Services

  19. 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...

  20. 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.

  1. The saproxylic beetle assemblage associated with different host trees in Southwest China

    Institute of Scientific and Technical Information of China (English)

    Jie Wu; Xiao-Dong Yu; Hong-Zhang Zhou

    2008-01-01

    Dead wood is a habitat for many insects and other small animals,some of which may be rare or endangered and in need of effective protection.In this paper,saproxylic beetle assemblages associated with different host trees in the subtropical forests in southwestern China were investigated.A total of 277 species (1 439 specimens) in 36 beetle families were collected from 117 dead wood samples,of which 101 samples were identified and respectively belonged to 12 tree genera.The number of saproxylic beetle species varied greatly among logs of different tree genera,with the highest diversity on logs of Juglans.Generally,broad-leaved trees had a higher richness and abundance of saproxylic species than coniferous trees.Cluster analysis revealed that assemblages from broad-leaved tree genera were generally similar (except for Betula) and assemblages from coniferous trees formed another distinct cluster.The subsequent indicator analysis proposed that there are different characteristic species for different cluster groups of host tree genera.In our study,log diameter has no positive influence on beetle species density.Conversely,comparisons of individual-based rarefaction curves suggested that beetle species richness was highest in the small diameter class both in coniferous and broad-leaved tree genera.With increased wood decay,proportion of habitat specialists (saproxylic beetles living on one tree genus)decreased,whereas proportion of habitat generalists (living on more than three tree genera)increased.The beetle species density was found to be higher in early stages,and decreased in later stages as well.A negative influence of altitude on saproxylic beetle species richness and abundance was detected.It was indicated that different tree genera and altitudes possibly display cross effects in modulating the altitudinal distribution and host preference of the beetles.

  2. Compatible spanning trees

    OpenAIRE

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

    2014-01-01

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

  3. Counting trees using symmetries

    CERN Document Server

    Bernardi, Olivier

    2012-01-01

    We present a new approach for counting trees, and we apply it to count multitype Cayley trees and to prove the multivariate Lagrange inversion formula. The gist of our approach is to exploit the symmetries of refined enumerative formulas: proving these symmetries is easy, and once the symmetries are proved the formulas follow effortlessly. Somewhat surprisingly, our formula for the generating function of multitype Cayley trees appears to be new, and implies certain recent results by Bousquet-M\\'elou and Chapuy. We also adapt our approach to recover known enumerative formulas for cacti counted according to their degree distribution.

  4. The gravity apple tree

    Science.gov (United States)

    Espinosa Aldama, Mariana

    2015-04-01

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

  5. The TS-Tree

    DEFF Research Database (Denmark)

    Assent, Ira; Krieger, Ralph; Afschari, Farzad;

    2008-01-01

    -dimensional data in an overlap-free manner. During query processing, powerful pruning via quantized separator and meta data information greatly reduces the number of pages which have to be accessed, resulting in substantial speed-up. In thorough experiments on synthetic and real world time series data we......, the efficiency benefits of indexing are lost. In this paper, we propose the TS-tree (time series tree), an index structure for efficient time series retrieval and similarity search. Exploiting inherent properties of time series quantization and dimensionality reduction, the TS-tree indexes high...

  6. Evolutionary tree reconstruction

    Science.gov (United States)

    Cheeseman, Peter; Kanefsky, Bob

    1990-01-01

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

  7. Are leaves optimally designed for self-support? An investigation on giant monocots.

    Science.gov (United States)

    Tadrist, Loïc; Darbois-Texier, Baptiste

    2016-05-01

    Leaves are the organs that intercept light and create photosynthesis. Efficient light interception is provided by leaves oriented orthogonal to most of the sun rays. Except in the polar regions, this means orthogonal to the direction of acceleration due to gravity, or simply horizontal. The leaves of almost all terrestrial plants grow in a gravity field that tends to bend them downward and therefore may counteract light interception. Plants thus allocate biomass for self-support in order to maintain their leaves horizontal. To compete with other species (inter-species competition), as well as other individuals within the same species (intra-species competition), self-support must be achieved with the least biomass produced. This study examines to what extent leaves are designed to self-support. We show here that a basic mechanical model provides the optimal dimensions of a leaf for light interception and self-support. These results are compared to measurements made on leaves of various giant monocot species, especially palm trees and banana trees. The comparison between experiments and model predictions shows that the longer palms are optimally designed for self-support whereas shorter leaves are shaped predominantly by other parameters of selection. PMID:26920248

  8. Extractability of radiocesium from processed green tea leaves with hot water. The first emergent tea leaves harvested after the TEPCO's Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    In some tea tree planting areas within 300 km from the TEPCO's Fukushima Daiichi Nuclear Power Plant (FNPP), it was found that newly emerged tea plant leaves for green tea contained two radiocesium species (cesium-134 and cesium-137). In this study, using processed green tea leaves for drinking, extraction ratios of radiocesium under several brew conditions were observed. When 90 deg C water was used, 50-70% of radiocesium was extracted into the water, while 54-60% of radiocesium was extracted with 60 deg C water. A part of radiocesium would be removed from leaves if the leaves were washed with 20 and 60 deg C water before brewing, and the efficiencies were 11 and 32%, respectively. Newly emerged camellia leaves were used to simulate the radiocesium removal ratio from raw tea leaves by washing and boiling; radioactivity concentration was decreased to 60% of the original concentration with washing and 10 min boiling. From these results, it was found that almost half of the radiocesium would not be removed from raw or processed tea leaves. The values obtained in the present study could be used for internal radiation dose estimation from tea leaves. (author)

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

    OpenAIRE

    Debasis Mishra; Dolf Talman

    2009-01-01

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

  10. ControlTree: Navigating and Selecting in a Large Tree

    OpenAIRE

    Appert, Caroline; Fekete, Jean-Daniel

    2006-01-01

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

  11. Species-Level Differences in Hyperspectral Metrics among Tropical Rainforest Trees as Determined by a Tree-Based Classifier

    Directory of Open Access Journals (Sweden)

    Dar A. Roberts

    2012-06-01

    Full Text Available This study explores a method to classify seven tropical rainforest tree species from full-range (400–2,500 nm hyperspectral data acquired at tissue (leaf and bark, pixel and crown scales using laboratory and airborne sensors. Metrics that respond to vegetation chemistry and structure were derived using narrowband indices, derivative- and absorption-based techniques, and spectral mixture analysis. We then used the Random Forests tree-based classifier to discriminate species with minimally-correlated, importance-ranked metrics. At all scales, best overall accuracies were achieved with metrics derived from all four techniques and that targeted chemical and structural properties across the visible to shortwave infrared spectrum (400–2500 nm. For tissue spectra, overall accuracies were 86.8% for leaves, 74.2% for bark, and 84.9% for leaves plus bark. Variation in tissue metrics was best explained by an axis of red absorption related to photosynthetic leaves and an axis distinguishing bark water and other chemical absorption features. Overall accuracies for individual tree crowns were 71.5% for pixel spectra, 70.6% crown-mean spectra, and 87.4% for a pixel-majority technique. At pixel and crown scales, tree structure and phenology at the time of image acquisition were important factors that determined species spectral separability.

  12. Tree-Indexed Processes

    OpenAIRE

    Pemantle, Robin

    1995-01-01

    This article examines a recent body of work on stochastic processes indexed by a tree. Emphasis is on the application of this new framework to existing probability models. Proofs are largely omitted, with references provided.

  13. Tree-like tableaux

    CERN Document Server

    Aval, Jean-Christophe; Nadeau, Philippe

    2011-01-01

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

  14. Generalized constructive tree weights

    International Nuclear Information System (INIS)

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

  15. Value tree analysis

    International Nuclear Information System (INIS)

    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.)

  16. The tree BVOC index.

    Science.gov (United States)

    Simpson, J R; McPherson, E G

    2011-01-01

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

  17. 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...

  18. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

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

  19. Loops and trees

    Science.gov (United States)

    Caron-Huot, S.

    2011-05-01

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

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

    OpenAIRE

    Havet, Frédéric

    2002-01-01

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

  1. Multiscale singularity trees

    DEFF Research Database (Denmark)

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

    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....

  2. Tree-Level Formalism

    OpenAIRE

    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 sup...

  3. Minimum Error Tree Decomposition

    OpenAIRE

    Liu, L; Ma, Y.; Wilkins, D.; Bian, Z.; Ying, X

    2013-01-01

    This paper describes a generalization of previous methods for constructing tree-structured belief network with hidden variables. The major new feature of the described method is the ability to produce a tree decomposition even when there are errors in the correlation data among the input variables. This is an important extension of existing methods since the correlational coefficients usually cannot be measured with precision. The technique involves using a greedy search algorithm that locall...

  4. Visualisation of Regression Trees

    OpenAIRE

    Brunsdon, Chris

    2007-01-01

    he regression tree [1] has been used as a tool for exploring multivariate data sets for some time. As in multiple linear regression, the technique is applied to a data set consisting of a contin- uous response variable y and a set of predictor variables { x 1 ,x 2 ,...,x k } which may be continuous or categorical. However, instead of modelling y as a linear function of the predictors, regression trees model y as a series of ...

  5. 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....

  6. 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...... 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....

  7. Biased Range Trees

    CERN Document Server

    Dujmovic, Vida; Morin, Pat

    2008-01-01

    A data structure, called a biased range tree, is presented that preprocesses a set S of n points in R^2 and a query distribution D for 2-sided orthogonal range counting queries. The expected query time for this data structure, when queries are drawn according to D, matches, to within a constant factor, that of the optimal decision tree for S and D. The memory and preprocessing requirements of the data structure are O(n log n).

  8. Urban tree mortality

    OpenAIRE

    Roman, Lara Angelica

    2013-01-01

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

  9. Information flow on trees

    OpenAIRE

    Mossel, Elchanan; Peres, Yuval

    2003-01-01

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

  10. Tree Improvement Glossary

    DEFF Research Database (Denmark)

    Schmidt, Lars Holger

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

  11. 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

  12. Infrasonic wind noise under a deciduous tree canopy.

    Science.gov (United States)

    Webster, Jeremy; Raspet, Richard

    2015-05-01

    In a recent paper, the infrasonic wind noise measured at the floor of a pine forest was predicted from the measured wind velocity spectrum and profile within and above the trees [Raspet and Webster, J. Acoust. Soc. Am. 137, 651-659 (2015)]. This research studies the measured and predicted wind noise under a deciduous forest with and without leaves. A calculation of the turbulence-shear interaction pressures above the canopy predicts the low frequency peak in the wind noise spectrum. The calculated turbulence-turbulence interaction pressure due to the turbulence field near the ground predicts the measured wind noise spectrum in the higher frequency region. The low frequency peak displays little dependence on whether the trees have leaves or not. The high frequency contribution with leaves is approximately an order of magnitude smaller than the contribution without leaves. Wind noise levels with leaves are very similar to the wind noise levels in the pine forest. The calculated turbulence-shear contribution from the wind within the canopy is shown to be negligible in comparison to the turbulence-turbulence contribution in both cases. In addition, the effect of taller forests and smaller roughness lengths than those of the test forest on the turbulence-shear interaction is simulated based on measured meteorological parameters. PMID:25994698

  13. Maidenhair tree (Ginkgo biloba L.) and its wood

    OpenAIRE

    Torelli, Niko

    2015-01-01

    Ginkgo biloba (maidenhair tree) is the sole survivor of a genus that has changed little for more than 150 million years and is the only member of the phylum Ginkgophyta (Êliving fossilĚ). Ginkgo is dioecious and gimnospermous, but cones are not produced. It looks very much like a dicot tree except that its leaves have dichotomous veins and it bears naked ovules. Its unique feature amongst the seed plants is that fertilization is achieved by motile sperm. Its coniferoid wood lacks vessels. Ana...

  14. Can a fast­growing early­successional tree (Ochroma pyramidale, Malvaceae) accelerate forest succession?

    NARCIS (Netherlands)

    Vleut, I.; Levy-Tacher, S.I.; Boer, de W.F.; Galindo-Gonzalez, J.; Ramirez-Marcial, N.

    2013-01-01

    Species-specific traits of trees affect ecosystem dynamics, defining forest structure and understorey development. Ochroma pyramidale is a fast-growing tree species, with life-history traits that include low wood density, short-lived large leaves and a narrow open thin crown. We evaluated forest suc

  15. Determination of high molecular mass compounds from Amazonian plant's leaves

    International Nuclear Information System (INIS)

    The fractions of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuacu (Theobroma grandiflorum - Sterculiaceae), marupa (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data (1H and 13C NMR, IR). (author)

  16. PHYTOCHEMICAL SCREENING OF NERIUM OLEANDER LEAVES AND MOMORDICA CHARANTIA LEAVES

    Directory of Open Access Journals (Sweden)

    Santhi R

    2011-01-01

    Full Text Available The developing countries mostly rely on traditional medicines. The traditional medicine involves the use of different plant extracts or the bioactive constituents. This type of study provides the health application at affordable cost. This study such as ethnomedicine keenly represents one of the best avenues in searching new economic plants for medicine. In keeping this view in mind the present investigation is carried out in Nerium oleander and Momordica charantia leaves. Qualitative phytochemical analysis of these two plants confirms the presence of various phytochemicals like carbohydrates, cholesterol, protein, amino acid, alkaloid, flavonoids, tannins, saponins, cardiac glycosides, terpenoids, and phlobatinins in their aqueous leaf extracts leaves followed by ethanol, ethyl acetate, diethyl ether and chloroform. The results suggest that the phytochemical properties of the leaves for curing various ailments and possess potential antioxidant properties.

  17. Behavior Trees for Evolutionary Robotics.

    Science.gov (United States)

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

    2016-01-01

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

  18. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    This study documents variation of stable-carbon isotope ratios (13C/12C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  19. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    OpenAIRE

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal dif...

  20. Tree and tree-like species of Mexico: gymnosperms, monocotyledons, and tree ferns Especies arbóreas y arborescentes de México: gimnospermas, monocotiledóneas y helechos arborescentes

    OpenAIRE

    Martin Ricker; Hernández, Héctor M.

    2010-01-01

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

  1. Cisgenic apple trees; development, characterization, and performance.

    Science.gov (United States)

    Krens, Frans A; Schaart, Jan G; van der Burgh, Aranka M; Tinnenbroek-Capel, Iris E M; Groenwold, Remmelt; Kodde, Linda P; Broggini, Giovanni A L; Gessler, Cesare; Schouten, Henk J

    2015-01-01

    Two methods were developed for the generation of cisgenic apples. Both have been successfully applied producing trees. The first method avoids the use of any foreign selectable marker genes; only the gene-of-interest is integrated between the T-DNA border sequences. The second method makes use of recombinase-based marker excision. For the first method we used the MdMYB10 gene from a red-fleshed apple coding for a transcription factor involved in regulating anthocyanin biosynthesis. Red plantlets were obtained and presence of the cisgene was confirmed. Plantlets were grafted and grown in a greenhouse. After 3 years, the first flowers appeared, showing red petals. Pollination led to production of red-fleshed cisgenic apples. The second method used the pM(arker)F(ree) vector system, introducing the scab resistance gene Rvi6, derived from apple. Agrobacterium-mediated transformation, followed by selection on kanamycin, produced genetically modified apple lines. Next, leaves from in vitro material were treated to activate the recombinase leading to excision of selection genes. Subsequently, the leaf explants were subjected to negative selection for marker-free plantlets by inducing regeneration on medium containing 5-fluorocytosine. After verification of the marker-free nature, the obtained plants were grafted onto rootstocks. Young trees from four cisgenic lines and one intragenic line, all containing Rvi6, were planted in an orchard. Appropriate controls were incorporated in this trial. We scored scab incidence for three consecutive years on leaves after inoculations with Rvi6-avirulent strains. One cisgenic line and the intragenic line performed as well as the resistant control. In 2014 trees started to overcome their juvenile character and formed flowers and fruits. The first results of scoring scab symptoms on apple fruits were obtained. Apple fruits from susceptible controls showed scab symptoms, while fruits from cisgenic and intragenic lines were free of scab

  2. Cisgenic apple trees; development, characterization and performance

    Directory of Open Access Journals (Sweden)

    Frans A. Krens

    2015-04-01

    Full Text Available Two methods were developed for the generation of cisgenic apples. Both have been successfully applied producing trees. The first method avoids the use of any foreign selectable marker genes; only the gene-of-interest is integrated between the T-DNA border sequences. The second method makes use of recombinase-based marker excision. For the first method we used the MdMYB10 gene from a red-fleshed apple coding for a transcription factor involved in regulating anthocyanin biosynthesis. Red plantlets were obtained and presence of the cisgene was confirmed. Plantlets were grafted and grown in a greenhouse. After three years, the first flowers appeared, showing red petals. Pollination led to production of red-fleshed cisgenic apples. The second method used the pM(arkerF(ree vector system, introducing the scab resistance gene Rvi6, derived from apple. Agrobacterium-mediated transformation, followed by selection on kanamycin, produced genetically modified apple lines. Next, leaves from in vitro material were treated to activate the recombinase leading to excision of selection genes. Subsequently, the leaf explants were subjected to negative selection for marker-free plantlets by inducing regeneration on medium containing 5-fluorocytosine. After verification of the marker-free nature, the obtained plants were grafted onto rootstocks. Young trees from four cisgenic lines and one intragenic line, all containing Rvi6, were planted in an orchard. Appropriate controls were incorporated in this trial. We scored scab incidence for three consecutive years on leaves after inoculations with Rvi6-avirulent strains. One cisgenic line and the intragenic line performed as well as the resistant control. In 2014 trees started to overcome their juvenile character and formed flowers and fruits. The first results of scoring scab symptoms on apple fruits were obtained. Apple fruits from susceptible controls showed scab symptoms, while fruits from cisgenic and intragenic

  3. Determinação da matéria seca e teores de macronutrientes em folhas de frutíferas usando diferentes métodos de secagem Determination of dry matter and macronutrient content in leaves of fruit trees using different drying methods

    Directory of Open Access Journals (Sweden)

    Nericlenes Chaves Marcante

    2010-11-01

    Full Text Available O objetivo desse estudo foi avaliar diferentes métodos de secagem de folhas para três diferentes frutíferas (maracujá, pêssego e abacate, com relação à determinação da matéria seca e os teores foliares de macronutrientes. Foram coletadas amostras de folhas recém expandida de três culturas, do pomar da fazenda de ensino e pesquisa da FCAV-UNESP, câmpus de Jaboticabal, no mês de janeiro de 2010, coletando-se para cada cultura 12 amostras com 25 folhas cada. Os tratamentos constituíram-se por dois métodos de secagem, estufa de circulação de ar forçada regulada a uma temperatura de 70°C e o forno microondas (FMO. Avaliou-se a massa da matéria seca e os teores foliares de macronutrientes. Os resultados sugerem que os dois métodos de secagem testados se assemelham na determinação de matéria seca e nos teores foliares de macronutrientes para as culturas análisadas, exceto os teores de cálcio na cultura do pêssego.The objective of this study was to evaluate different methods of drying of leaves for three different fruit (passion fruit, peach and avocado, with respect to the determination of dry matter and foliar nutrients. Samples were collected from recently expanded leaves of three crops orchard Farm education and research FCAV-UNESP, Jaboticabal campus, in January 2010, by collecting 12 samples for each culture with 25 leaves. The treatments consisted of two drying methods, greenhouse circulation of air regulated to a temperature of 70°C and FMO. We evaluated the mass of dry matter and foliar nutrients. The results suggest that the two drying methods tested did not interfere in the determination of dry matter and foliar nutrients to crops analyzed, except the calcium levels in peach.

  4. Effects of water stress on the distribution of 14C-assimilates in young apple trees (mauls pumila mill.)

    International Nuclear Information System (INIS)

    Young apple trees were treated by water stress and 14CO2 was fed to leaves. Distribution of assimilates in source and sink organs was determined. The results show that plant water deficit increased the proportion of 14C-assimilates remained in source leaves, and decreased the proportion of 13C-assimilates exported into the developing fruits. Water stress also significantly decreased the photosynthetic rate of leaves and the growth rate of plants

  5. 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...

  6. Equiseparable chemical trees

    Directory of Open Access Journals (Sweden)

    BORIS FURTULA

    2003-07-01

    Full Text Available Let n1(e|T and n2(e|T denote the number of vertices of a tree T, lying on the two sides of the edge e. Let T1 and T2 be two trees with equal number of vertices, let e be an edge of T1 and f an edge of T2. Then e and f are said to be equiseparable if either n1(e|T1 = n1(e|T2 or n1(e|T1 = n2(e|T2. If all edges of T1 and T2 can be chosen so as to form equiseparable pairs, then T1 and T2 are equiseparable trees. A number of molecular structure-descriptors of equiseparable chemical trees coincide, implying that the corresponding alkane isomers must have similar physico-chemical properties. It is shown how equiseparable chemical trees can be constructed in a systematic manner.

  7. Odds-On Trees

    CERN Document Server

    Bose, Prosenjit; Douieb, Karim; Dujmovic, Vida; King, James; Morin, Pat

    2010-01-01

    Let R^d -> A be a query problem over R^d for which there exists a data structure S that can compute P(q) in O(log n) time for any query point q in R^d. Let D be a probability measure over R^d representing a distribution of queries. We describe a data structure called the odds-on tree, of size O(n^\\epsilon) that can be used as a filter that quickly computes P(q) for some query values q in R^d and relies on S for the remaining queries. With an odds-on tree, the expected query time for a point drawn according to D is O(H*+1), where H* is a lower-bound on the expected cost of any linear decision tree that solves P. Odds-on trees have a number of applications, including distribution-sensitive data structures for point location in 2-d, point-in-polytope testing in d dimensions, ray shooting in simple polygons, ray shooting in polytopes, nearest-neighbour queries in R^d, point-location in arrangements of hyperplanes in R^d, and many other geometric searching problems that can be solved in the linear-decision tree mo...

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

    Directory of Open Access Journals (Sweden)

    Durzan Don J

    2009-02-01

    Full Text Available Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors.

  9. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    Science.gov (United States)

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland. PMID:25588119

  10. Effect of mixing low palatable grasses and ipil ipil leaves on forage quality

    International Nuclear Information System (INIS)

    The study was conducted at the National Agricultural Research Centre, Islamabad, Pakistan to investigate the impact of mixing low palatable grasses namely Heteropogon contortus, Desmostachya bipinnata, Sorghum halepense and Chrysopogon aucheri with tree leaves of Leucaena leucocephala (Ipil ipil) in the ratio of 75:25, 50:50, 25:75, along with sole species on their chemical composition. Samples were analyzed for proximate parameters (crude protein (CP), crude fiber (CF), total ash and ether extract (EE)). The results revealed that there were significant differences in dry matter (DM) among different grasses. DM content of low palatable grasses was generally high (70-75%) as compared to Ipil ipil leaves (45-55%). DM content among mixtures was also variable. For the treatment grass 75% + Ipil ipil 25%, DM range was 65-70%, for grass 50% + Ipil ipil 50%, it was 60-65% and for grass 25% + Ipil ipil 75%, it was 55%. The CP value of the treatments showed significant variation ranging from less than 10% in grasses to almost 30% in pure Ipil ipil leaves. The mixtures had CP content corresponding to proportions of grasses and legume tree leaves. The CF values also varied significantly among the treatments. Grasses had in general higher CF content than legume leaves. It can be concluded that addition of Ipil ipil leaves to grasses improved overall nutrition especially CP of the feed. (author)

  11. The Urban Environment Can Modify Drought Stress of Small-Leaved Lime (Tilia cordata Mill. and Black Locust (Robinia pseudoacacia L.

    Directory of Open Access Journals (Sweden)

    Astrid Moser

    2016-03-01

    Full Text Available The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and are therefore advantageous over other, more susceptible species. However, the drought tolerance of urban trees in relation to the specific growth conditions in urban areas remains poorly researched. This study aimed to analyze the annual growth and drought tolerance of two common urban tree species, namely small-leaved lime (Tilia cordata Mill. (T. cordata and black locust (Robinia pseudoacacia L. (R. pseudoacacia, in two cities in southern Germany in relation to their urban growing conditions. Marked growth reductions during drought periods and subsequent fast recovery were found for R. pseudoacacia, whereas T. cordata exhibited continued reduced growth after a drought event, although these results were highly specific to the analyzed city. We further show that individual tree characteristics and environmental conditions significantly influence the growth of urban trees. Canopy openness and other aspects of the surrounding environment (water supply and open surface area of the tree pit, tree size, and tree species significantly affect urban tree growth and can modify the ability of trees to tolerate the drought stress in urban areas. Sustainable tree planting of well adapted tree species to their urban environment ensures healthy trees providing ecosystem services for a high quality of life in cities.

  12. An Evaluation of Paid Leave

    DEFF Research Database (Denmark)

    Albæk, Karsten

    This paper analyzes a labor market program which enables workers to leave employment temporarily with a compensation financed by the taxpayers. The main aim of the program was to increase the chances of the unemployed finding a job. However, the empirical analysis reveals a clear negative...... relationship between the unemployment rate and transition rates from employment into the paid leave scheme. Program participation is low, precisely in those labor market states, where the scheme has a potential to perform as a remedy by increasing the transition rate from unemployment to employment. Several...

  13. Active flows on trees

    CERN Document Server

    Forrow, Aden; Dunkel, Jörn

    2016-01-01

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

  14. Predictive Classification Trees

    Science.gov (United States)

    Dlugosz, Stephan; Müller-Funk, Ulrich

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

  15. 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...

  16. The gene tree delusion.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2016-01-01

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

  17. Estimation of Tree Lists from Airborne Laser Scanning Using Tree Model Clustering and k-MSN Imputation

    Directory of Open Access Journals (Sweden)

    Jörgen Wallerman

    2013-04-01

    Full Text Available Individual tree crowns may be delineated from airborne laser scanning (ALS data by segmentation of surface models or by 3D analysis. Segmentation of surface models benefits from using a priori knowledge about the proportions of tree crowns, which has not yet been utilized for 3D analysis to any great extent. In this study, an existing surface segmentation method was used as a basis for a new tree model 3D clustering method applied to ALS returns in 104 circular field plots with 12 m radius in pine-dominated boreal forest (64°14'N, 19°50'E. For each cluster below the tallest canopy layer, a parabolic surface was fitted to model a tree crown. The tree model clustering identified more trees than segmentation of the surface model, especially smaller trees below the tallest canopy layer. Stem attributes were estimated with k-Most Similar Neighbours (k-MSN imputation of the clusters based on field-measured trees. The accuracy at plot level from the k-MSN imputation (stem density root mean square error or RMSE 32.7%; stem volume RMSE 28.3% was similar to the corresponding results from the surface model (stem density RMSE 33.6%; stem volume RMSE 26.1% with leave-one-out cross-validation for one field plot at a time. Three-dimensional analysis of ALS data should also be evaluated in multi-layered forests since it identified a larger number of small trees below the tallest canopy layer.

  18. Tree domatic number in graphs

    OpenAIRE

    Xue-gang Chen

    2007-01-01

    A dominating set \\(S\\) in a graph \\(G\\) is a tree dominating set of \\(G\\) if the subgraph induced by \\(S\\) is a tree. The tree domatic number of \\(G\\) is the maximum number of pairwise disjoint tree dominating sets in \\(V(G)\\). First, some exact values of and sharp bounds for the tree domatic number are given. Then, we establish a sharp lower bound for the number of edges in a connected graph of given order and given tree domatic number, and we characterize the extremal graphs. Finally, we sh...

  19. How to leave your job.

    Science.gov (United States)

    Gurden, Dean

    2016-08-10

    'Leaving a job is never a decision you should take lightly,' says Nick Simpson, CEO of health recruitment agency MSI Group. 'Every nursing professional has things about their job they find frustrating and daily tasks they may not necessarily enjoy doing, but it's important to consider the positive aspects of your current role before you make a decision.' PMID:27507390

  20. A Suffix Tree Or Not a Suffix Tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    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...... particular we do not require that S ends with a unique symbol. This corresponds to considering the more general definition of implicit or extended suffix trees. Such general suffix trees have many applications and are for example needed to allow efficient updates when suffix trees are built online. We prove...... that r is a suffix tree if and only if it is realized by a string S of length n - 1, and we give a linear-time algorithm for inferring S when the first letter on each edge is known. This generalizes the work of I et al....

  1. Model Persamaan Massa Karbon Akar Pohon dan Root-Shoot Ratio Massa Karbon (Equation Models of Tree Root Carbon Mass and Root-Shoot Carbon Mass Ratio

    Directory of Open Access Journals (Sweden)

    Elias .

    2011-03-01

    Full Text Available The case study was conducted in the area of Acacia mangium plantation at BKPH Parung Panjang, KPH Bogor. The objective of the study was to formulate equation models of tree root carbon mass and root to shoot carbon mass ratio of the plantation. It was found that carbon content in the parts of tree biomass (stems, branches, twigs, leaves, and roots was different, in which the highest and the lowest carbon content was in the main stem of the tree and in the leaves, respectively. The main stem and leaves of tree accounted for 70% of tree biomass. The root-shoot ratio of root biomass to tree biomass above the ground and the root-shoot ratio of root biomass to main stem biomass was 0.1443 and 0.25771, respectively, in which 75% of tree carbon mass was in the main stem and roots of tree. It was also found that the root-shoot ratio of root carbon mass to tree carbon mass above the ground and the root-shoot ratio of root carbon mass to tree main stem carbon mass was 0.1442 and 0.2034, respectively. All allometric equation models of tree root carbon mass of A. mangium have a high goodness-of-fit as indicated by its high adjusted R2.Keywords: Acacia mangium, allometric, root-shoot ratio, biomass, carbon mass

  2. Uptake and Translocation of Manganese by Native Tree Species in a Constructed Wetland Treating Landfill Leachates

    Directory of Open Access Journals (Sweden)

    A. Snow

    2007-01-01

    Full Text Available A surface flow constructed wetland was used to treat stormwater runoff from surrounding watersheds which are comprised primarily of commercial properties and two former landfills. The uptake of manganese by red maple, white birch and red spruce trees growing under flooded soil conditions in the constructed wetland was compared to that of the same trees growing under well drained soil conditions in a nearby reference site. The seasonal variability of manganese and its distribution in different compartments of these trees (leaves, twigs, branches, trunk wood, trunk bark and roots were studied. The average manganese concentrations in the aboveground compartments of red maple, white birch and red spruce trees were within the range of manganese concentrations reported in the literature for these trees. The concentrations of manganese in the aboveground compartments of red maple, white birch and red spruce trees in the reference site were significantly greater than those in the constructed wetland (with the exception of manganese concentrations in the trunk wood of red maple trees because of the acidic soil conditions of the reference site. The percent distribution of manganese in the aboveground compartments of trees did not vary during the growing season. Higher concentrations of manganese were present in the trunk bark and either the leaves or twigs of species on both the constructed wetland and the reference site regardless of the sampling date.

  3. Nitrogen availability, leaf life span and nitrogen conservation mechanisms in leaves of tropical trees Disponibilidade de nitrogênio, longevidade foliar e mecanismos de conservação de nitrogênio em folhas de espécies arbóreas tropicais

    Directory of Open Access Journals (Sweden)

    Guilherme Nascimento Corte

    2009-12-01

    Full Text Available Evergreen species of temperate regions are dominant in low-nutrient soils. This feature is attributed to more efficient mechanisms of nutrient economy. Nevertheless, the cashew (Anacardium occidentale- Anacardiaceae, a deciduous species, is native to regions in Brazil with sandy soil, whilst the annatto (Bixa orellana- Bixaceae, classified as an evergreen species native to tropical America, grows spontaneously in regions with more humid soils. Evergreens contain robust leaves that can resist adverse conditions for longer. The physical aspects of the leaves and mechanisms of nutrient economy between the two species were compared, in order to verify whether the deciduous species had more efficient mechanisms that might explain its occurrence in regions of low soil fertility. The mechanisms of nitrogen economy were also compared for the two species at available concentrations of this nutrient. The following were analysed: (i leaf life span, (ii physical leaf characteristics (leaf mass per area, and rupture strain, (iii nitrogenous compounds (nitrogen, chlorophyll, and protein, (iv nitrogen conservation mechanisms (nitrogen resorption efficiency, resorption proficiency, and use efficiency, and (v nitrogen conservation mechanisms under different availability of this mineral. The higher values of leaf mass per area and leaf rupture strain found in A. occidentale were related to its longer leaf life span. A. occidentale showed lower concentrations of nitrogen and protein in the leaves than B. orellana. Under lower nitrogen availability, A. occidentale had higher nitrogen resorption proficiency, nitrogen use efficiency and leaf life span than B. orellana. These characteristics may contribute to the adaptation of this species to sandy soils with low nitrogen content.Perenifólias de clima temperado são dominantes em solos pouco férteis. Essa característica é atribuída a mecanismos mais eficientes de economia de nutrientes. O cajueiro (Anacardium

  4. Safety evaluation of Morinda citrifolia (noni) leaves extract: assessment of genotoxicity, oral short term and subchronic toxicity

    OpenAIRE

    Alicia Lagarto; Viviana Bueno; Nelson Merino; Janet Piloto; Odalys Valdes; Guillermo Aparicio; Addis Bellma; Micaela Couret; Yamile Vega

    2013-01-01

    Morinda citrifolia L (noni) is an evergreen or small tree that grows in many tropical regions of the world. The use of the noni leaves has not been so studied however; there are reports of its pharmacological benefits. Aims: The objective of this investigation was to assess the genotoxicity, short-term, and subchronic oral toxicity of Morinda citrifolia L leaves aqueous extract. Methods: The genotoxicity of the M. citrifolia extract was investigated by measuring the frequency of micr...

  5. The Effect of Giving Moringa Leaves Extract to Pregnant Women Working in Informal Sector on DNA Damage

    OpenAIRE

    Muis, Masyita; Hadju, Veni; S. Russeng, Syamsiar; Burhanuddin, Laode

    2015-01-01

    Moringa leaves are the leaves of the Moringa tree containing various macro and micro nutrients and active ingredients that act as antioxidants. We assess the effect of leaf extracts of Moringa in pregnant women informal workers to DNA damage This study design was randomized, double-blind, controlled trials. Pregnant women working in informal sector (generally the laborers and sellers). Statistical analysis using paired and independent t-tests. Characteristics of the subjects before t...

  6. Lead Accummulation Potential By Leaves With Abundant Trichomes (Muntingia Calabura L.) And Rare Trichomes (Mimusops Elengi L.) In Makassar, Indonesia

    OpenAIRE

    Suhadiyah, Sri

    2013-01-01

    A study of lead accumulation by leaves with abundant trichomes (Muntingia calabura L.) and leaves with rare trichomes (Mimusop elengi L.) in Makassar, Indonesia was conducted in August 2011 by using wet ashing method and Atomic Absorption Spectrophotometer. The objective of this study was to find out the influence of trichome abundance on lead accumulation in shade trees. Results from multiple regression analysis with interval level of 95% indicated a significant correlation between lead (Pb)...

  7. Photosynthesis in relation to radiation and leaf position in cashew trees

    International Nuclear Information System (INIS)

    In field grown cashew trees (Anacardium occidentale) net photosynthetic rate (PN) was maximum in leaves grown in all four directions (East - E, West - W, South - S and North - N) between 11 to 12 h. Between 15 to 16 h, photosynthetically active radiation (PAR) and PN were higher in W than in other directions, however stomatal conductance (gs) and transpiration rate (E) were similar in all the four directions. Maximum PN was found in the leaves of middle portion of the tree. Irradiance was more important for PN than gs, intercellular CO2, and E which did not exert significant differences at different directions and timings

  8. Christmas Tree Category Manual.

    Science.gov (United States)

    Bowman, James S.; Turmel, Jon P.

    This manual provides information needed to meet the standards for pesticide applicator certification. Pests and diseases of christmas tree plantations are identified and discussed. Section one deals with weeds and woody plants and the application, formulation and effects of herbicides in controlling them. Section two discusses specific diseases…

  9. 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 algebra s * base tree Subject RIV: BA - General Mathematics Impact factor: 0.621, year: 2014 http://link.springer.com/article/10.1007/s11083-013-9316-2

  10. The Sacred Tree.

    Science.gov (United States)

    Lethbridge Univ. (Alberta).

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

  11. Oklee Tree Project

    International Nuclear Information System (INIS)

    The Oklee Tree Project is a cooperative effort between the Agricultural Utilization Research Institute, University of Minnesota-Crookston (UMC), Natural Resources Research Institute (NRRI), Minnesota Power (MP), and local, state, and federal agencies designed to demonstrate the feasibility of growing hybrid poplar trees as cash crop in Minnesota. Local meetings were held to assess grower interest in a long-term commitment to growing trees as a crop. Most potential growers were concerned with annual payments, provisions for land reclamation if the contract length was less than 15 years, and a market with a fair price for the wood. Other concerns were availability of technical assistance and securing vendors for land preparation, planting stock, planting, and weed control. Features included in the program to plant 3,000 acres of trees on Conservation Reserve Program (CRP) land eligible for five-year contract extensions were cost sharing from the Consolidated Farm Service Agency, an $85/acre payment for establishment and maintenance from the Legislative Commission on Minnesota Resources (LCMR), and 25-year contracts with MP. Contracts with MP include guaranteed purchase of wood and annual payments to participating growers. Landowner interest and participation in this program, along with outreach activities such as newsletters, field days, information meetings, and media coverage has increased awareness and acceptance of hybrid poplar as a potential crop in the region. (author)

  12. Tree-string duality

    International Nuclear Information System (INIS)

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

  13. 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)

  14. Relations between behavior of HLB and Iron application to Citrus trees

    OpenAIRE

    Matsuyama, T.; Muraki, S.; Subandiyah, S.; Joko, T.; Ono, H.; Masaoka, Y

    2014-01-01

    Citrus Greening Disease or Huanglongbing (HLB) is one of the most serious citrus diseases in the world. There are no effective methods to cure this disease, and major countermeasures include detection of initial detection and cutting down  infected trees. Thus, HLB delivers serious impact to the agricultural economy. It is well known that an HLB infected tree shows specific symptoms like micronutrient deficiency. We revealed that iron (Fe) content of citrus leaves showing symptoms f...

  15. Tree cover and biomass increase in a southern African savanna despite growing elephant population

    OpenAIRE

    Kalwij, J. M.; De Boer, W.F.; L. Mucina; Prins, H.H.T.; Skarpe, Christina; Winterbach, C

    2010-01-01

    The growing elephant populations in many parts of southern Africa raise concerns of a detrimental loss of trees, resulting in overall reduction of biodiversity and ecosystem functioning. Elephant distribution and density can be steered through artificial water points (AWPs). However, this leaves resident vegetation no relief during dry seasons. We studied how the introduction of eight AWPs in 1996 affected the spatiotemporal tree-structure dynamics in central Chobe National Park, an unfenced ...

  16. Statistical Methods for Recovering 3D Models of Trees from Sensor Data

    OpenAIRE

    Binney, Jonathan; Sukhatme, Gaurav

    2007-01-01

    Measuring the biological parameters of trees can be a time consuming process. Currently, there are two main choices: painstakingly count leaves and measure hundreds of branches by hand, or use rough approximations obtained from sensors like hemispherical cameras or airborne laser scans. We hope to find ways of reconstructing models of trees in greater detail, by collecting large amounts of sensor data at relatively close range and fitting a model to this data. Once the model is created, param...

  17. An Assessment of Ecosystem Services Provided by Street Trees in Bangkok, Thailand

    OpenAIRE

    SOONSAWAD, NATTHANIJ

    2014-01-01

    This study focuses on the analysis of ecosystem services provided by green spaces in Bangkok, Thailand, as a potential tool to address urban and environmental problems there. The analyses are divided into two parts for achieving two objectives, 1) estimating the magnitude of ecosystem services provided by public street trees, and 2) examining the relationship between stable isotopic data of tree leaves and the environmental quality of Bangkok's streets. The findings could be used to identify ...

  18. Toxic hazards of the industrial atmospheric pollutant sulphur dioxide on tree crops

    OpenAIRE

    Rani, B Dr

    2009-01-01

    A study was conducted to assess the effect of the industrial atmospheric pollutant, sulphur dioxide on tree crops such as coconut. The area around the Travancore Titanium Products at Trivandrum district of Kerala State, India, concerned with the manufacture of titanium dioxide was selected as the experimental site. Coconut palm (Cocos nucifera L.)was selected as the test crop since it dominates the tree crops in the area. Chemical analysis of leaves and nuts were made to assess the extent of...

  19. Organic inputs from agroforestry trees on farms for improving soil quality and crop productivity in Ethiopia

    OpenAIRE

    Teklay, Tesfay

    2005-01-01

    Indigenous agroforestry trees and shrubs on farmlands are an under-utilized resource that can be used as green manures (GM) to alleviate declining soil fertility and productivity. The aims of studies described in this thesis were to investigate: (1) the seasonal dynamics in chemical contents of foliage from selected tree species potentially available as sources of GM, (2) rates and patterns of mineralization of nutrients during decomposition of leaves, (3) nutrient limitations for microbial p...

  20. A Proactive Tree Recovery Mechanism for Resilient Overlay Multicast

    Directory of Open Access Journals (Sweden)

    Poorna Satyanarayana B.

    2012-06-01

    Full Text Available Overlay multicast constructs a multicast delivery tree among end hosts. An important problem for making overlay multicast more dependable is how to recover from node departures in order to minimize the disruption of service to those affected nodes. In this paper, we propose a proactive tree recovery mechanism to make the overlay multicast resilient to these failures and unexpected events. The salient feature of the approach is that rescue plans for multiple non-leaf nodes can work together for their respective children when they fail or leave at the same time. Extensive simulations demonstrate that our proactive approach can recover from node departures much faster than reactive methods, while the quality of trees restored and the cost of recovery are reasonable

  1. Bounds On The Disjunctive Total Domination Number Of A Tree

    Directory of Open Access Journals (Sweden)

    Henning Michael A.

    2016-02-01

    . A leaf of G is a vertex of degree 1, while a support vertex of G is a vertex adjacent to a leaf. We show that if T is a tree of order n with ℓ leaves and s support vertices, then 2(n−ℓ+3/5≤γtd(T≤(n+s−1/2$2(n - \\ell + 3/5 \\le \\gamma _t^d (T \\le (n + s - 1/2$ and we characterize the families of trees which attain these bounds. For every tree T, we show have γt(T/γtd(T<2$\\gamma _t (T/\\gamma _t^d (T < 2$ and this bound is asymptotically tight.

  2. Carbon, cesium and iodine isotopes in Japanese cedar leaves from Iwaki, Fukushima

    DEFF Research Database (Denmark)

    Xu, Sheng; Cook, Gordon T.; Cresswell, Alan J.;

    2016-01-01

    Japanese cedar leaves from Iwaki, Fukushima were analyzed for carbon, cesium and iodine isotopic compositions before and after the 2011 nuclear accident. The Δ14C values reflect ambient atmospheric 14C concentrations during the year the leaves were sampled/defoliated, and also previous year(s). The...... elevated 129I and 134,137Cs concentrations are attributed to direct exposure to the radioactive fallout for the pre-fallout-expended leaves and to internal translocation from older parts of the tree for post-fallout-expended leaves. 134Cs/137Cs and 129I/137Cs activity ratios suggest insignificant isotopic...... and elemental fractionation during translocation. However, fractionation between radioiodine and radiocesium is significant during transportation from the source....

  3. Tree Formation Using Coordinate Method

    Directory of Open Access Journals (Sweden)

    Monika Choudhary

    2015-06-01

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

  4. 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.

  5. Learning Stochastic Tree Edit Distance

    OpenAIRE

    Bernard, Marc; Habrard, Amaury; Sebban, Marc

    2006-01-01

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

  6. Cover Tree Bayesian Reinforcement Learning

    OpenAIRE

    Tziortziotis, Nikolaos; Dimitrakakis, Christos; Blekas, Konstantinos

    2013-01-01

    This paper proposes an online tree-based Bayesian approach for reinforcement learning. For inference, we employ a generalised context tree model. This defines a distribution on multivariate Gaussian piecewise-linear models, which can be updated in closed form. The tree structure itself is constructed using the cover tree method, which remains efficient in high dimensional spaces. We combine the model with Thompson sampling and approximate dynamic programming to obtain effective exploration po...

  7. Connected searching of weighted trees

    CERN Document Server

    Dereniowski, Dariusz

    2010-01-01

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

  8. Nitrogen fixation in legume trees: Measurement based on 15N techniques

    International Nuclear Information System (INIS)

    A field experiment has been conducted to measure the N2-fixation in six legume trees, namely Gliricidia sepium(F1), Sesbania sesban(F2), Caliandra tetragona(F3), Flemengia conges-7ta(F4), Acacia mangium(F5), and Leucena leucocephala (F6), using 15N techniques, e.g. the isotope dilution method. For this technique a reference tress, that is a non N2--fixing trees has to be used. In this experiment three reference trees were planted, but only one was used, which above ground growth was equal to the legyme trees. The reference tree chosen was Eucalyptus alba (R1). Data obtained from this experiment show that in general the legume trees have growth then the reference trees expressed, in dray weight of various plant parts and plants and total-N uptake (TN). At harvest some of the legume and reference tree have reached a 2.5 m height. The percentage of N2-fixation(%-fix) ranges from 50-70%. The highest %N-Fix was shown by Leucena leucocephala (F6) (70%N-Fix). High %N-Fix does not necessarily mean hgh N-Fix uptake(gn/tree)too. The N-Fix appears to be determined by the TN (gn/tree). The highest N-Fix was contributed by the leaves, which also has the highest percentage of total -N(%TN) compare to the other plant parts, i.e. roots, stem, and branches

  9. A Class of Graceful Trees

    Institute of Scientific and Technical Information of China (English)

    孟凡洪; 苏耕; 杨继

    2000-01-01

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

  10. Quantitative estimates of uptake and internal cycling of 15N-depleted fertilizer in mature walnut trees

    International Nuclear Information System (INIS)

    In mature fruit trees, internal recycling is an important source of N for the growth of new wood, leaves and fruits. Using 15N-depleted fertilizer, i.e. 14N-enriched, N-uptake efficiency and the magnitude of internal N cycling were studied in mature walnut trees. Two kg of 14N-labelled ammonium sulfate N were applied per tree, and compartmentation of N was followed over a period of 6 years by analyzing catkins, pistillate flowers, leaves and fruits each year for total N content and isotopic composition. Subsequently, two of the six labelled trees were excavated and analyzed for labelled-N content. The data indicate that mature walnut uses most of the N accumulated from soil and fertilizer for storage purposes, to be remobilized for new growth within 2 years, and about half of the total-N pool in a mature tree is present as non-structural compounds, available for recycling. (author)

  11. Sick Leave and Subjective Health Complaints

    OpenAIRE

    2007-01-01

    The aims of this thesis were to identify risk factors for high levels of sick leave and investigate what – if anything – can be done to reduce sick leave. What is the role of “subjective health complaints”, coping, and psychosocial work factors in relation to sick leave, and to what extent do these factors and the sick leave relate to quality of life? Are there any interventions with a documented effect on sick leave in the literature? Is it possible to influence sick leave thr...

  12. 喀斯特山区9种常见树木叶片在防火期的阻火性分析%Fire Resistance of Leaves During Fire Prevention Period of Nine Common Tree Species in Karst Mountain Regions

    Institute of Scientific and Technical Information of China (English)

    梁琴; 陶建平; 邓锋; 王微; 方文; 何平

    2015-01-01

    Objective]Guizhou province of China is one of the most typical karst regions in the world,at the same time,its fire disturbance is highly representative in the national forest fires. With the fragile karst environment plus severe forest fire disturbance,the fire prevention is particularly important and urgent in the Karst mountain regions of Guizhou province. Among the many fire prevention measures,the biological firebreak with its versatile,and long-term advantage, has attracted much attention of scholars and managers. The primary task of biological firebreak is to select the appropriate pyrophyte ( the plants with good fire resistance) . However,there is few study focus on the pyrophyte selection for karst mountain regions. On the other hand,with regard to pyrophyte selection,there is no uniform evaluation method up to now. It’s necessary to select appropriate fire-resistant tree species which are also suitable for growing in karst mountain regions,[Method]we investigated 9 common tree species from karst mountain regions of northwest Guizhou. Based on the measurements of four leaf traits ( benzene -alcohol extract content,ash content,ignition time and heat value) during fire prevention period,we used the Principal Component Analysis ( PCA) ,combined with the Weighted-Technique for Order Preference by Similarity to an Ideal Solution ( W-TOPSIS) ,to analyze the fire resistance.[Result]The Viburnum foetidum var. ceanothoides’s and Castanea seguinii’s benzene-alcohol extractive content were 2. 12 and 1. 97 times higher than Murica nana’s; The ash content of M. nana’s and V. foetidum var. ceanothoides’were the highest,and Castanea seguinii’s,Vaccinium pseudorobustum ’s and Ligustrum quihoui ’s were the lowest; The ignition time of L. quihoui, Castanea seguinii and Cotoneaster glaucophyllus var. glaucophyllus were the longest, and Puracantha fortuneana, Cunninghamia lanceolata and Rhododendron simsii were the shortest;The highest heat value were

  13. Rituals, ceremonies and customs related to sacred trees with a special reference to the Middle East

    Directory of Open Access Journals (Sweden)

    Dafni Amots

    2007-07-01

    Full Text Available Abstract Tree worship is very common worldwide. This field study surveys the ceremonies and customs related to sacred trees in present-day Israel; it includes the results of interviews with 98 informants in thirty-one Arab, Bedouin, and Druze villages in the Galilee. The main results are: 1. Sacred trees were treated as another kind of sacred entity with all their metaphysical as well as physical manifestations. 2. There is not even one ceremony or custom that is peculiar only to a sacred tree and is not performed in other sacred places (such as a saint's grave or a mosque. 3. Few customs, such as: quarrel settling (= Sulkha, leaving objects to absorb the divine blessing and leaving objects for charity seem to be characteristic of this region, only. 4. In modern times, sacred trees were never recorded, in Israel, as centres for official religious ceremonies including sacrifices, nor as places for the performing of rites of passage. 5. There is some variation among the different ethnic groups: Kissing trees and worshipping them is more common among the Druze although carrying out burials under the tree, leaving water and rain-making ceremonies under them have not been recorded in this group. Passing judgments under the tree is more typical of the Bedouin in which the sacred trees were commonly used as a public social centre. Most of the customs surveyed here are known from other parts of the world. The differences between Muslims and Druze are related to the latter's belief in the transmigration of souls.

  14. Uptake and translocation of radiocesium in cedar leaves following the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Cryptomeria japonica trees in the area surrounding Fukushima, Japan, intercepted 137Cs present in atmospheric deposits soon after the Fukushima nuclear accident in March 2011. To study the uptake and translocation of 137Cs in C. japonica leaves, we analyzed activity concentrations of 137Cs and the concentration ratios of 137Cs to 133Cs (137Cs/133Cs) in old and new leaves of C. japonica collected from a forest on Mount Tsukuba between 9 and 15 months after the accident. Both isotopes were also analyzed in throughfall, bulk precipitation and soil extracts. Water of atmospheric and soil origin were used as proxies for deciphering the absorption from leaf surfaces and root systems, respectively. Results indicate that 20–40% of foliar 137Cs existed inside the leaf, while 60–80% adhered to the leaf surface. The 137Cs/133Cs ratios inside leaves that had sprouted before the accident were considerably higher than that of the soil extract and lower than that of throughfall and bulk precipitation. Additionally, more than 80% of 137Cs in throughfall and bulk precipitation was present in the dissolved form, which is available for foliar uptake, indicating that a portion of the 137Cs inside old leaves was presumably absorbed from the leaf surface. New leaves that sprouted after the accident had similar 137Cs/133Cs ratios to that of the old leaves, suggesting that internal 137Cs was translocated from old to new leaves. For 17 species of woody plants other than C. japonica, new leaves that sprouted after the accident also contained 137Cs, and their 137Cs/133Cs ratios were equal to or higher than that of the soil extract. These results suggested that foliar uptake and further translocation of 137Cs is an important vector of contamination in various tree species during or just after radioactive fallout. - Highlights: • 137Cs was absorbed into cedar leaves from the leaf surface. • 137Cs in new leaves of cedar trees was mainly supplied by translocation. • Over 80% of 137Cs

  15. 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. PMID:26356921

  16. Changes of main secondary metabolites in leaves of Ginkgo biloba in response to ozone fumigation

    Institute of Scientific and Technical Information of China (English)

    HE Xingyuan; HUANG Wei; CHEN Wei; DONG Tian; LIU Changbing; CHEN Zhenju; XU Sheng; RUAN Yanan

    2009-01-01

    To investigate the effect of elevated O3 on the accumulation of main secondary metabolites in leaves of Ginkgo biloba L., four-year-old trees were exposed in open-top chambers with ambient air and the air with twice ambient O3 concentration in Shenyang in 2006.Elevated O3 increased the concentrations of terpenes, but decreased the concentrations of phenolics in G.biloba leaves.The results showed that secondary compounds from G.biloba leaves responded to the elevated O3 exposure in a different way when compared to previous studies which showed elevated O3 increased the concentrations of phenolics but had no effect on the terpenes in leaves of other deciduous trees.Furthermore, reduced synthesis of phenolics may decrease the resistance of G.biloba to O3 and other environmental factors.On the other hand, the induced synthesis of terpenes may enhance the antioxidant abilities in G.biloba leaves at the end of O3 fumigation.

  17. Sequence Determination of a Novel Tripeptide Isolated from the Young Leaves of Azadirachta indica A. Juss

    Directory of Open Access Journals (Sweden)

    M. Rajeswari Prabha

    2013-01-01

    Full Text Available The neem tree has long been recognized for its unique properties, both against insects and in improving human health. Every part of the tree has been used as a traditional medicine for household remedy against various human ailments, from antiquity. Although the occurrence of various phytochemicals in neem has been studied, we have identified the presence of a novel tripeptide in the young leaves of neem using a simple and inexpensive paper chromatographic method, detected by Cu(II-ninhydrin reagent. The peptide nature of the isolated compound is confirmed by spectral studies. The sequence of the peptide is determined using de novo sequencing by tandem MS after purification.

  18. Ensemble of Causal Trees

    International Nuclear Information System (INIS)

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite. (author)

  19. Ensemble of Causal Trees

    Science.gov (United States)

    Bialas, Piotr

    2003-10-01

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite.

  20. Morphological variability of leaves of Sorbus torminalis (L. Crantz in Poland

    Directory of Open Access Journals (Sweden)

    Leszek Bednorz

    2011-04-01

    Full Text Available This paper presents the results of the study on morphological variability of leaves of a scattered tree species Sorbus torminalis (L. Crantz in Poland. The leaves from short- and long shoots were collected from 17 localities widespread within the range of the species in Poland. Leaves were measured according to 15 morphological traits. The biometric data were subjected to multivariate statistical analysis in attempt to define variability between local populations. Most of the leaf traits are significantly correlated and are characterised by moderate level of variation. The average among population component of variation was 32.82% and 27.46% for leaves on short- and long shoots, respectively. The differences between sampled populations are significant, but only a weak geographical pattern of this differentiation was detected. Clinal type of variation was ascertained in two traits. Leaf traits which discriminate best the studied populations are also indicated. It was proved that leaves on short shoots differ markedly in shape and size from those of long shoots. Leaves on long shoots are steadier, but morphological trait values are less correlated. The study also confirmed the occurrence of individuals with leaves characteristic for S. torminalis var. perincisa Borbas et Feck and S. torminalis f. mollis Beck in a few Polish populations.

  1. Tree Level Gauge Mediation

    OpenAIRE

    Nardecchia, Marco; Romanino, Andrea; Ziegler, Robert

    2009-01-01

    We propose a new scheme in which supersymmetry breaking is communicated to the MSSM sfermions by GUT gauge interactions at the tree level. The (positive) contribution of MSSM fields to $\\text{Str}(\\mathcal{M}^2)$ is automatically compensated by a (negative) contribution from heavy fields. Sfermion masses are flavour universal, thus solving the supersymmetric flavour problem. In the simplest SO(10) embedding, the ratio of different sfermion masses is predicted and differs from mSugra and other...

  2. Tree Interpolation in Vampire

    OpenAIRE

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

    2013-01-01

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

  3. Tree farming; Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-07-01

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

  4. Tree farming. Traedjordbruk

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-07-01

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

  5. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

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

  6. Fermilab Capacitor Tree

    International Nuclear Information System (INIS)

    The Fermilab Capacitor Tree is a capacitor bank used in series with the feeders carrying 3-phase, 13.8 kV power to the main ring power supply system. Its function is to reduce the voltage droop of the power supplies at high currents, by acting in series resonance with the leakage inductances of the system. A description is given of the electrical system and operational experience since May 1976

  7. Turgidity-dependent petiole flexibility enables efficient water use by a tree subjected to water stress.

    Science.gov (United States)

    Gonzalez-Rodriguez, David; Cournède, Paul-Henry; de Langre, Emmanuel

    2016-06-01

    Water stress is a major cause of tree mortality. In response to drought, leaves wilt due to an increase in petiole flexibility. We present an analytical model coupling petiole mechanics, thermal balance, and xylem hydraulics to investigate the role of petiole flexibility in protecting a tree from water stress. Our model suggests that turgidity-dependent petiole flexibility can significantly attenuate the minimal xylem pressure and thus reduce the risk of cavitation. Moreover, we show that petiole flexibility increases water use efficiency by trees under water stress. PMID:26992577

  8. Somatic Embryogenesis Induction and Plant Regeneration in Strawberry Tree (Arbutus unedo L.).

    Science.gov (United States)

    Martins, João F; Correia, Sandra I; Canhoto, Jorge M

    2016-01-01

    Somatic embryogenesis is a powerful tool both for cloning and studies of genetic transformation and embryo development. Most protocols for somatic embryogenesis induction start from zygotic embryos or embryonic-derived tissues which do not allow the propagation of elite trees. In the present study, a reliable protocol for somatic embryogenesis induction from adult trees of strawberry tree is described. Leaves from in vitro proliferating shoots were used to induce somatic embryo formation on a medium containing an auxin and a cytokinin. Somatic embryos germinated in a plant growth regulator-free medium. PMID:26619869

  9. Chemical constituents and antioxidant activity of the essential oil from leaves of Annona vepretorum Mart. (Annonaceae)

    OpenAIRE

    Camila de Souza Araújo; Ana Paula de Oliveira; Rafaely Nascimento Lima; Péricles Barreto Alves; Tâmara Coimbra Diniz; Jackson Roberto Guedes da Silva Almeida

    2015-01-01

    Background: Annona vepretorum (AV) is a native tree from Caatinga biome (semiarid region of Brazil) popularly known as “araticum” and “pinha da Caatinga.” Objective: This study was carried out to evaluate the chemical constituents and antioxidant activity (AA) of the essential oil from the leaves from AV (EO-Av) collected in Petrolina, Pernambuco, Brazil. Materials and Methods: Fresh leaves of AV were cut into pieces, and subjected to distillation for 2 h in a clevenger-type apparatus. Gas ch...

  10. Evaluation of antimicrobial activity of the crude ethanol extract of Eugenia uniflora L. leaves

    OpenAIRE

    F. C. PIMENTA; L.M.F. TRESVENZOL; J.R. Paula; S. M.T. SABóIA-MORAIS; T. S. FIúZA

    2009-01-01

    Eugenia unifl ora L. is a tree whose leaves are used in popular medicine as an antihypertensive, antimicrobial drug, in the treatment of bronchitis, infl uenza and as an antipyretic. This paper reports the antimicrobial activity of a crude ethanol extract of E. unifl ora L. leaves. The crude extract was prepared from material collected in Goiânia, Goiás (Brazil), dried, pulverized and subjected to phytochemical screening. The antimicrobial activity was tested against spore-forming and non-spo...

  11. Effect of N and NPK fertilizers on early field performance of narrow-leaved ash, Fraxinus angustifolia.

    Science.gov (United States)

    Cicek, Emrah; Yilmaz, Faruk; Yilmaz, Murat

    2010-01-01

    The effect of fertilization in the first growing season on early survival and growth of narrow-leaved ash (NLA) (Fraxinus angustifolia ssp. oxycarpa) was evaluated throughout the first 3 years of growth in Adapazari, Turkey. A randomized complete block design with four replications was established to investigate fertilization effects. Granular N urea [46%, (NH2)2CO, NH2-N] and NPK (15/15/15%; NH3-N, P2O5, K2O) fertilizers were applied in mid-May of the first growing season. Fertilization treatments per tree were control, 67 g NPK (equal to 10/10/10 g N/P2O5 /K2O tree(-1)), 133 g NPK (20/20/20 g N/P2O5 /K2O tree(-1)), 33 g urea N (15 g N tree(-1)) and 54 g urea N (25 g N tree(-1)). After three growing seasons under these fertilizer treatments, 98% of trees were still viable. Compared to the control treatment, fertilization had a large and positive effect on diameter and height growth during the first 3 years of growth. However, since there were no significant differences among the fertilized plots in terms of tree diameter and height growth, addition of P and K to the fertilizer regime was not beneficial. The results show that N fertilization in the first growing season has the potential to improve early field growth of narrow-leaved ash. PMID:20648820

  12. Pushdown machines for the macro tree transducer

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1986-01-01

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

  13. 24 Ways to Kill a Tree

    OpenAIRE

    Appleton, Bonnie Lee, 1948-2012

    2009-01-01

    Few residential trees die of old age. Mechanical damage and improper tree care kill more trees than any insects or diseases. This publication shows 24 ways to void making the tree-damaging mistake. Few of these items alone would kill a tree, but multiple problems will certainly stress, and could eventually kill, a tree.

  14. Evolutionarily stable strategy of carbon and nitrogen investments in forest leaves and its application in vegetation dynamic modeling

    Science.gov (United States)

    Weng, E.; Farrior, C.; Dybzinski, R.; Pacala, S. W.

    2015-12-01

    Leaf mass per area (LMA) and leaf lifespan (LL) are two highly correlated plant traits that are key to plant physiological and ecological properties. Usually, low LMA means short LL, high nitrogen (N) content per unit mass, and fast turnover rates of nutrients; high LMA leads to long LL, low N content, and slow turnover rates. Deciduous trees with low LMA and short lifespan leaves have low carbon cost but high nitrogen demand; and evergreen trees, with high LMA and long lifespan leaves, have high carbon cost but low nitrogen demand. These relationships lead to: 1) evergreen trees have higher leaf area index than deciduous trees; 2) evergreen trees' carbon use efficiency is lower than the deciduous trees' because of their thick leaves and therefore high maintenance respiration; 3) the advantage of evergreens trees brought by their extra leaves over deciduous trees diminishes with increase N in ecosystem. These facts determine who will win when trees compete with each other in a N-limited ecosystem. In this study, we formulate a mathematical model according to the relationships between LMA, LL, leaf nitrogen, and leaf building and maintenance cost, where LMA is the fundamental variable determining the other three. We analyze the evolutionarily stable strategies (ESSs) of LMA with this mathematical model by examining the benefits of carbon and nitrogen investments to leaves in ecosystems with different N. The model shows the ESS converges to low LMA at high N and high LMA at low N. At intermediate N, there are two ESSs at low and high ends of LMA, respectively. The ESS also leads to low forest productivity by outcompeting the possible high productive strategies. We design a simulation scheme in an individual-based competition model (LM3-PPA) to simulate forest dynamics as results of the competition between deciduous and evergreen trees in three different biomes, which are temperate deciduous forest, deciduous-evergreen mixed forest, and boreal evergreen forest. The

  15. 香樟在徐州地区的引种及前景%Prospect of Growing Camphor Tree in Xuzhou Region

    Institute of Scientific and Technical Information of China (English)

    何树川

    2009-01-01

    Camphor tree has been widely used due to its unique characteritics of large and tall trunk, dense branches and leaves, large and shady canopy,magnificent tree form, long life cycle and evergreen. With global warming,scientific and technological progress and the improvement of plant cultivation techniques, the scope of planting Camphor tree is expanded. In this paper,the conditions and prospect of growing Camphor tree in Xuzhou were illustrated from aspects of biological characteristics,feasibility of growing the trees in Xuzhou, critical techniques of planting and tending..

  16. Tree Canopy Characterization for EO-1 Reflective and Thermal Infrared Validation Studies: Rochester, New York

    Science.gov (United States)

    Ballard, Jerrell R., Jr.; Smith, James A.

    2002-01-01

    The tree canopy characterization presented herein provided ground and tree canopy data for different types of tree canopies in support of EO-1 reflective and thermal infrared validation studies. These characterization efforts during August and September of 2001 included stem and trunk location surveys, tree structure geometry measurements, meteorology, and leaf area index (LAI) measurements. Measurements were also collected on thermal and reflective spectral properties of leaves, tree bark, leaf litter, soil, and grass. The data presented in this report were used to generate synthetic reflective and thermal infrared scenes and images that were used for the EO-1 Validation Program. The data also were used to evaluate whether the EO-1 ALI reflective channels can be combined with the Landsat-7 ETM+ thermal infrared channel to estimate canopy temperature, and also test the effects of separating the thermal and reflective measurements in time resulting from satellite formation flying.

  17. Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment

    Directory of Open Access Journals (Sweden)

    Mahmoud Elhariri

    2016-01-01

    Full Text Available In Egypt, the River Red Gum (Eucalyptus camaldulensis is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%. Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment.

  18. Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment.

    Science.gov (United States)

    Elhariri, Mahmoud; Hamza, Dalia; Elhelw, Rehab; Refai, Mohamed

    2016-01-01

    In Egypt, the River Red Gum (Eucalyptus camaldulensis) is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%). Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment. PMID:26884765

  19. 1-Skeletons of the Spanning Tree Problems with Additional Constraints

    Directory of Open Access Journals (Sweden)

    V. A. Bondarenko

    2015-10-01

    Full Text Available In this paper, we study polyhedral properties of two spanning tree problems with additional constraints. In the first problem, it is required to find a tree with a minimum sum of edge weights among all spanning trees with the number of leaves less than or equal to a given value. In the second problem, an additional constraint is the assumption that the degree of all nodes of the spanning tree does not exceed a given value. The recognition versions of both problems are NP-complete. We consider polytopes of these problems and their 1-skeletons. We prove that in both cases it is a NP-complete problem to determine whether the vertices of 1-skeleton are adjacent. Although it is possible to obtain a superpolynomial lower bounds on the clique numbers of these graphs. These values characterize the time complexity in a broad class of algorithms based on linear comparisons. The results indicate a fundamental difference between combinatorial and geometric properties of the considered problems from the classical minimum spanning tree problem.

  20. The distribution of weaver ant pheromones on host trees

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2007-01-01

    The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for ...... leaves. Also there was a positive correlation between spot density and the likelihood of being detected by ants. Anal spots may thus function as reliable cues to interacting species and be an important factor in shaping the community around Oecophylla colonies.......The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for...... correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared to...

  1. MEMORY ENHANCING ACTIVITIES OF FICUS RELIGIOSA LEAVES IN RODENTS

    Directory of Open Access Journals (Sweden)

    Wangkhem Bandana Devi

    2011-03-01

    Full Text Available Ficus religiosa, a sacred tree to both Hindus and Buddhists, is recognized for its medicinal as well as religious purposes in India. The ethanolic extract prepared from the leaves of Ficus religiosa was studied for memory enhancing activities in Wistar albino rats and Swiss albino mice. The present study was carried out on five models such as Elevated-Plus Maze, Step through passive avoidance test, Sodium nitrite intoxication, Hebb-Williams Maze and Radial Arm Maze to evaluate learning and memory parameters. Scopolamine (1mg/kg, i.p was used as inducing agent in Elevated-plus maze, Step through passive avoidance test and sodium nitrite (95mg/kg, s.c was used as inducing agent in Sodium nitrite intoxication model. Piracetam (200mg/kg, i.p was used as standard nootropic agent for all the models except for Sodium nitrite intoxication; Mentat was used as positive control for Sodium nitrite intoxication model. The ethanolic extract of Ficus religiosa leaves significantly improved memory and reversed the amnesia induced by scopolamine and hypoxia induced by sodium nitrite. The ethanolic extract of Ficus religiosa leaves (100 mg/kg was comparable to that of piracetam (200 mg/kg and Mentat (100mg/kg. From the results of the present study it is concluded that the leaf extract of Ficus religiosa might possess anti-amnesic as well as nootropic properties. Also the major active constituents present in its leaves such as amino acids may be responsible for these activities.

  2. Morphometric characteristics of the leaves of Greek maple (Acer heldreichii Orph in central Serbia

    Directory of Open Access Journals (Sweden)

    Perović Marko

    2007-01-01

    Full Text Available The taxonomic characteristics of Greek maple (Acer heldreichii Orph were studied based on the analysis of leaf characteristics, by comparative-morphological method. The study was performed at three localities in central Serbia: Goč, Jastrebac and Rudnik. 30 normally developed trees were selected per each locality, and 30 leaves were selected from each tree for the analysis. The study includes 8 measured and 15 derived characteristics of leaves. The study results were statistically processed by correlation analysis, analysis of variance and cluster-analysis. It is concluded that there are two varieties, var. heldreichii and var. macropterum. Four forms are set aside in the variety macropterum: f. typicum f. dissectum, f. Equiloba and f. rotundiloba. The populations are relatively homogeneous, and both varieties occur at all three localities in significant numbers.

  3. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C-3 species

    NARCIS (Netherlands)

    Poorter, H; VanBerkel, Y; Baxter, R; DenHertog, J; Dijkstra, P; Gifford, RM; Griffin, KL; Roumet, C; Roy, J

    1997-01-01

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO2, These species comprised wild and agricultural herbaceous plants as well as tree seedlings, Both average responses a

  4. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  5. LAI based trees selection for mid latitude urban developments: A microclimatic study in Cairo, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Mohamad [School of Architecture, University of Sheffield, Sheffield (United Kingdom); Department of Architecture, Military Technical College, Cairo (Egypt); Sharples, Stephen [School of Architecture, University of Sheffield, Sheffield (United Kingdom); Yahiya, Mahmoud [Department of Mechanical Engineering, University of Sheffield, Sheffield (United Kingdom); Mechanical Engineering Branch, Military Technical College, Cairo (Egypt)

    2010-02-15

    To study the leaf area index, LAI, based thermal performance in distinguishing trees for Cairo's urban developments, ENVI-met plants database was used as platform for a foliage modeling parameter, the leaf area density, LAD. Two Egyptian trees; Ficus elastica, and Peltophorum pterocarpum were simulated in 2 urban sites with one having no trees, whilst the second is having Ficus nitida trees. Trees LAD values were calculated using flat leaves' trees LAI definition to produce maximum ground solid shadow at peak time. An empirical value of 1 for LAI is applied to numerically introduce LAD values for ENVI-met. Basically, different meteorological records showed improvements for pedestrian comfort and ambient microclimate of the building using F. elastica. About 40-50% interception of direct radiation, reductions in surfaces' fluxes around trees and in radiant temperature T{sub mrt} in comparison to base cases gave preferability to F. elastica. The lack of soil water prevented evapotranspiration to take place effectively and the reduced wind speeds concluded negligible air temperature differences from both base cases except slightly appeared with the F. elastica. Results show that a flat leaves tree if does not validate LAI of 1, the ground shading would not fulfill about 50% direct radiation interception and this value can be used as a reference for urban trees selection. Further simulations were held to investigate LAI value of maximum direct radiation interception. Performing additional simulations, F. elastica of LAI of 3 intercepted almost 84% of direct radiation and revealed implications about urban trees in practice and its actual LAI. (author)

  6. Water relations of evergreen and drought-deciduous trees along a seasonally dry tropical forest chronosequence.

    Science.gov (United States)

    Hasselquist, Niles J; Allen, Michael F; Santiago, Louis S

    2010-12-01

    Seasonally dry tropical forests (SDTF) are characterized by pronounced seasonality in rainfall, and as a result trees in these forests must endure seasonal variation in soil water availability. Furthermore, SDTF on the northern Yucatan Peninsula, Mexico, have a legacy of disturbances, thereby creating a patchy mosaic of different seral stages undergoing secondary succession. We examined the water status of six canopy tree species, representing contrasting leaf phenology (evergreen vs. drought-deciduous) at three seral stages along a fire chronosequence in order to better understand strategies that trees use to overcome seasonal water limitations. The early-seral forest was characterized by high soil water evaporation and low soil moisture, and consequently early-seral trees exhibited lower midday bulk leaf water potentials (Ψ(L)) relative to late-seral trees (-1.01 ± 0.14 and -0.54 ± 0.07 MPa, respectively). Although Ψ(L) did not differ between evergreen and drought-deciduous trees, results from stable isotope analyses indicated different strategies to overcome seasonal water limitations. Differences were especially pronounced in the early-seral stage where evergreen trees had significantly lower xylem water δ(18)O values relative to drought-deciduous trees (-2.6 ± 0.5 and 0.3 ± 0.6‰, respectively), indicating evergreen species used deeper sources of water. In contrast, drought-deciduous trees showed greater enrichment of foliar (18)O (∆(18)O(l)) and (13)C, suggesting lower stomatal conductance and greater water-use efficiency. Thus, the rapid development of deep roots appears to be an important strategy enabling evergreen species to overcome seasonal water limitation, whereas, in addition to losing a portion of their leaves, drought-deciduous trees minimize water loss from remaining leaves during the dry season. PMID:20658152

  7. Utilization of Biotechnology on Some Forest Trees in Turkey

    Directory of Open Access Journals (Sweden)

    Esra Nurten Yer

    2014-12-01

    Full Text Available Background and Purpose: Raw wood material requirements are increasing with rapid population growth both in Turkey and in the world. In order to supply deficit for closure of forest products, productivity and quality of production should be improved. Basic ways to increase efficiency in forest production involves silvicultural implementations and classical tree breeding studies. Genetic variation can be increased by utilizing the existing diversity. Thus, new combinations can be obtained and we can raise efficiency using some selection strategies. At this point, biotechnological methods are required to meet the genetic material. Studies of forest tree breeding are a slow process due to the size of the genome and the length of the tree life span. Biotechnological applications in forest trees provide many important benefits in terms of time saving and reducing cost when compared to classical breeding studies. Sustainable forestry practices are gaining rapid acceleration via biotechnology and modern sciences practices. In this study, for some forest tree species in Turkey, the evaluated biotechnology methods included; 1- tissue culture and clonal propagation, 2- molecular marker applications, 3- marker assisted selection and breeding, 4-genomic and proteomic studies, 5- genetic modification and genetic engineering applications. Conclusions: In this study, the works were carried out on forest tree breeding/propagation in Turkey and it was mainly focused on vegetative production techniques with 25 broadleaves and 9 conifer taxa, which were possible to express. Molecular genetic studies were carried out on 12 broad leaves taxa and 9 conifer taxa; genetic transformation studies were conducted on poplar species. Thus, it might be suggested that a combination of biotechnological tools and traditional propagation methods will ensure advantage for the development of forest-tree species.

  8. Completely Independent Spanning Trees in (Partial k-Trees

    Directory of Open Access Journals (Sweden)

    Matsushita Masayoshi

    2015-08-01

    Full Text Available Two spanning trees T1 and T2 of a graph G are completely independent if, for any two vertices u and v, the paths from u to v in T1 and T2 are internally disjoint. For a graph G, we denote the maximum number of pairwise completely independent spanning trees by cist(G. In this paper, we consider cist(G when G is a partial k-tree.

  9. Effect of tree-crop intercropping on a young Populus tomentosa plantation

    Institute of Scientific and Technical Information of China (English)

    JIANG Yuezhong; QIN Guanghua

    2007-01-01

    In order to study the effect of tree crop intercropping on a young plantation ofPopulus tomentosa in the plains along the Yellow River,field experiments were conducted by observing the growth of the plantation,the nutrient content in leaves,the nutrient and water content in the soil,and the output of crops.The relationship between forest growth and nutrient content in the tree leaves and the soil were analyzed.Results show that tree crop intercropping in young plantations can not only improve soil water content,but also enhance the contents of organic matter and the available nitrogen,phosphorus and potassium in soil resulting in the vigorous growth of the individual trees.Diameter at breast height (DBH) was positively related to the contents of organic matter in the soil,and the contents of N,P and K in the tree leaves had correlation coefficients of 0.967,0.955,0.988 and 0.972,respectively.Whole tree leaf area,crown width,number of branches and the mean length of branches in the intercropped plantation (intercropped with watermelon and vegetables,peanut and winter wheat,and soybean) were,respectively,1.70-3.0 times,2.22-2.47 times,1.0-1.41 times and 1.70-2.32 times of those of CK (without intercropping).Diameter at breast height (DBH) and tree height in the intercropped plantation were 50.5%-136.7% and 27%-59.5% higher than those of the CK,respectively.The study also showed that intercropping with watermelon and vegetables proved to have the highest economic return among the treatments adopted.Tree crop intercropping in young plantations is an effective measure to increase forest growth and economic benefit.

  10. Optimization of DNA Extraction for RAPD and ISSR Analysis of Arbutus unedo L. Leaves

    OpenAIRE

    Paula Baptista; José Alberto Pereira; Olga Sá

    2011-01-01

    Genetic analysis of plants relies on high yields of pure DNA. For the strawberry tree (Arbutus unedo) this represents a great challenge since leaves can accumulate large amounts of polysaccharides, polyphenols and secondary metabolites, which co-purify with DNA. For this specie, standard protocols do not produce efficient yields of high-quality amplifiable DNA. Here, we present for the first time an improved leaf-tissue protocol, based on the standard cetyl trimethyl ammonium bromide protocol...

  11. Transcriptome analysis of Huanglongbing-infected sweet orange leaves using RNA sequencing and quantitative PCR

    OpenAIRE

    Parra, Cynthia C.; Kunta, Madhurababu; da Graça, John V; Louzada, Eliezer S.

    2014-01-01

    RNA sequencing (RNA-seq) methods provide a complete description of RNA transcripts including alternative splicing and small RNA characterization. RNA-seq performed in our laboratory on healthy and Huanglongbing (HLB)-infected young leaves revealed that 4,044 transcripts were up-regulated and 2,562 were down-regulated in the diseased trees. Moreover, a number of genes showed alternative splicing events including exon skipping, intron retention, and 5' and 3' alternative splicing. Furthermore, ...

  12. Dye-sensitized solar cells based on dyes extracted from dried plant leaves

    OpenAIRE

    Taya, Sofyan A.; Taher M. El-Agez; ELREFI, Kamal S.

    2015-01-01

    In this work, natural dyes were extracted from dried plant leaves of plant cream, apricot, figs, apples, sage, thyme, mint, Ziziphus jujuba, orange, shade tree, basil, berry, Mirabelle plum, Victoria plum, peach, mango, pomegranate, banana, guava, and fluoridation-treated plant. The extracts were used as photosensitizers for dye-sensitized solar cells (DSSCs). The cells were assembled using nanostructured TiO2 films. The best performance was observed for the DSSC sensitized with Ziziphus juju...

  13. PHARMACOGNOSTIC AND PHYSICO- CHEMICAL EVALUATION OF LEAVES OF TECOMA GAUDICHAUDI DC (BIGNONIACEAE)

    OpenAIRE

    Kedar K.A; S. R. CHAUDHARI; A. Srinivasa Rao

    2013-01-01

    Tecoma gaudichaudi DC (Family Bignoniaceae) is a small tree of height 9-12m. and various Tecoma species are attractive to bees, butterflies or birds. Present study focuses on determination of some quantitative microscopical factors of leaves of Tecoma gaudichaudi DC includes Stomatal no., vein islet no etc. Under physicochemical standards various parameters were checked, such as ash value, acid insoluble ash value and moisture content etc. It helps in to check purity of crude drug. Ultimately...

  14. Characteristics of element composition of aerosols adsorbed on leaves by radioactivation analysis and their effects on plants

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, Takejiro; Koshikawa, Masami [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan); Sase, Hiroyuki; Masuzawa, Toshiyuki; Kawashima, Munetsugu; Takada, Jitsuya; Matsushita, Rokuji

    1999-01-01

    Aerosol deposits on leaves of various trees, especially cedar in different regions of Japan were collected to characterize the elemental composition using neutron activation analysis, ICP-AES, etc. and also investigate the effects of deposit aerosols on plants and the efficacy as an indicator for air pollution. Compared with the elemental composition of the soil, Se, Cr, Au, Br, As, Sb, Ag, etc. were more abundant in aerosols on cedar leaves. Especially, Sb is thought to be mostly derived from combustion of fossil fuels (exhaust gas from cars, etc.). Since Sb was accumulated on leaves at high levels and the analytical precision for Sb by neutron radioactivation was very high, the element was thought useful as an indicator for air pollution. If the amounts of Sb on the leaves of cedar and pine trees, which are widely distributed in Japan are determined, the degrees of pollution in all regions of Japan would be determined. In cedar trees of Saitama Prefecture where the deposit amounts of aerosols were comparatively larger, 42% of stoma was covered with the deposits, resulting that the rate of cuticular transpiration was increased and the amounts of basic elements leached from the leave surface was also increased. Thus, it was suggested that these changes might be the cause of recent declining of cedars in Japanese urban regions. (M.N.)

  15. Characteristics of element composition of aerosols adsorbed on leaves by radioactivation analysis and their effects on plants

    International Nuclear Information System (INIS)

    Aerosol deposits on leaves of various trees, especially cedar in different regions of Japan were collected to characterize the elemental composition using neutron activation analysis, ICP-AES, etc. and also investigate the effects of deposit aerosols on plants and the efficacy as an indicator for air pollution. Compared with the elemental composition of the soil, Se, Cr, Au, Br, As, Sb, Ag, etc. were more abundant in aerosols on cedar leaves. Especially, Sb is thought to be mostly derived from combustion of fossil fuels (exhaust gas from cars, etc.). Since Sb was accumulated on leaves at high levels and the analytical precision for Sb by neutron radioactivation was very high, the element was thought useful as an indicator for air pollution. If the amounts of Sb on the leaves of cedar and pine trees, which are widely distributed in Japan are determined, the degrees of pollution in all regions of Japan would be determined. In cedar trees of Saitama Prefecture where the deposit amounts of aerosols were comparatively larger, 42% of stoma was covered with the deposits, resulting that the rate of cuticular transpiration was increased and the amounts of basic elements leached from the leave surface was also increased. Thus, it was suggested that these changes might be the cause of recent declining of cedars in Japanese urban regions. (M.N.)

  16. Tree Level Gauge Mediation

    CERN Document Server

    Nardecchia, Marco; Ziegler, Robert

    2009-01-01

    We propose a new scheme in which supersymmetry breaking is communicated to the MSSM sfermions by GUT gauge interactions at the tree level. The (positive) contribution of MSSM fields to $\\text{Str}(\\mathcal{M}^2)$ is automatically compensated by a (negative) contribution from heavy fields. Sfermion masses are flavour universal, thus solving the supersymmetric flavour problem. In the simplest SO(10) embedding, the ratio of different sfermion masses is predicted and differs from mSugra and other schemes, thus making this framework testable at the LHC. Gaugino masses are generated at the loop level but enhanced by model dependent factors.

  17. Optical Inspection and Morphological Analysis of Diospyros kaki Plant Leaves for the Detection of Circular Leaf Spot Disease

    Directory of Open Access Journals (Sweden)

    Ruchire Eranga Wijesinghe

    2016-08-01

    Full Text Available The feasibility of using the bio-photonic imaging technique to assess symptoms of circular leaf spot (CLS disease in Diospyros kaki (persimmon leaf samples was investigated. Leaf samples were selected from persimmon plantations and were categorized into three groups: healthy leaf samples, infected leaf samples, and healthy-looking leaf samples from infected trees. Visually non-identifiable reduction of the palisade parenchyma cell layer thickness is the main initial symptom, which occurs at the initial stage of the disease. Therefore, we established a non-destructive bio-photonic inspection method using a 1310 nm swept source optical coherence tomography (SS-OCT system. These results confirm that this method is able to identify morphological differences between healthy leaves from infected trees and leaves from healthy and infected trees. In addition, this method has the potential to generate significant cost savings and good control of CLS disease in persimmon fields.

  18. Transmission and Propagation of 'Candidatus Liberibacter asiaticus' by Grafting with Individual Citrus Leaves.

    Science.gov (United States)

    Hilf, Mark E; Lewis, Reid S

    2016-05-01

    Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with a systemic infection by the bacterium 'Candidatus Liberibacter asiaticus'. Transmission of the bacterium in the field is by the Asian citrus psyllid, Diaphorina citri Kuwayama. Experimental propagation of 'Ca. L. asiaticus' is done primarily by grafting pieces of bud wood from an infected plant. To produce a small-scale model system for investigation of pathogen biology, we investigated grafting single leaves from infected citrus plants as sources of inoculum for propagation of the bacterium. In total, 162 plants ranging in age from 3 to 18 months were grafted. Grafting with intact asymptomatic and HLB-symptomatic leaves resulted in 61 of 78 (78%) and 35 of 41 (85%) of the plants infected with 'Ca. L. asiaticus', respectively. Inoculum consisting of the leaf petiole only or only an inoculum tissue remnant under the bark of the receptor tree resulted in 6 of 12 (50%) and 7 of 31 (23%) infected trees, respectively. Real-time polymerase chain reaction (qPCR) assays verified the infection in plants, a majority of which developed the foliar blotchy mottle symptom considered diagnostic for HLB, while some plants also displayed the stunted, chlorotic shoots for which the disease is named. The qPCR data together with the symptoms displayed demonstrated that individual leaves from infected trees can serve as effective inoculum sources for transmission and propagation of 'Ca. L. asiaticus' via grafting. PMID:26807818

  19. Limit theorems for sequences of random trees

    OpenAIRE

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

    2004-01-01

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

  20. Barking up the Right Tree

    Science.gov (United States)

    Houston, Paul D.

    2006-01-01

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

  1. 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.

  2. 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.

  3. 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...

  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)

    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. Human decision error (HUMDEE) trees

    Energy Technology Data Exchange (ETDEWEB)

    Ostrom, L.T.

    1993-08-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision.

  7. NMR-Based Metabolomic Analysis of Huanglongbing-Asymptomatic and -Symptomatic Citrus Trees.

    Science.gov (United States)

    Freitas, Deisy dos Santos; Carlos, Eduardo Fermino; Gil, Márcia Cristina Soares de Souza; Vieira, Luiz Gonzaga Esteves; Alcantara, Glaucia Braz

    2015-09-01

    Huanglongbing (HLB) is one of the most severe diseases that affects citrus trees worldwide and is associated with the yet uncultured bacteria Candidatus Liberibacter spp. To assess the metabolomic differences between HLB-asymptomatic and -symptomatic tissues, extracts from leaf and root samples taken from a uniform 6-year-old commercial orchard of Valencia trees were subjected to nuclear magnetic resonance (NMR) and chemometrics. The results show that the symptomatic trees had higher sucrose content in their leaves and no variation in their roots. In addition, proline betaine and malate were detected in smaller amounts in the HLB-affected symptomatic leaves. The changes in metabolic processes of the plant in response to HLB are corroborated by the relationship between the bacterial levels and the metabolic profiles. PMID:26285838

  8. Estimating Single Tree Stem Volume of Pinus sylvestris Using Airborne Laser Scanner and Multispectral Line Scanner Data

    Directory of Open Access Journals (Sweden)

    Barbara Koch

    2011-05-01

    Full Text Available So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris in a study site in the south-west of Germany. First, tree crowns were automatically delineated using both multispectral and laser scanner data. Next, tree height, crown diameter and crown volume were derived for each crown segment. All combinations of the derived tree features were used as explanatory variables in allometric models to predict the stem volume. A model with tree height and crown diameter had the best performance with respect to the prediction accuracy determined by a leave-one-out cross-validation: Root Mean Square Error (RMSE = 24.02% and Bias = 1.36%.

  9. [Magnetic Response of Dust-loaded Leaves in Parks of Shanghai to Atmospheric Heavy Metal Pollution].

    Science.gov (United States)

    Liu, Fei; Chu, Hui-min; Zheng, Xiang-min

    2015-12-01

    To reveal the magnetic response to the atmospheric heavy metal pollution in leaves along urban parks, Camphor leaf samples, widely distributed at urban parks, were collected along the year leading wind direction of Shanghai, by setting two vertical and horizontal sections, using rock magnetic properties and heavy metal contents analysis. The results showed that the magnetic minerals of samples were predominated by ferromagnetic minerals, and both the concentration and grain size of magnetite particles gradually decreased with the winter monsoon direction from the main industrial district. A rigorous cleaning of leaves using ultrasonic agitator washer could remove about 63%-90% of low-field susceptibility values of the leaves, and this strongly indicated that the intensity of magnetic signal was mainly controlled by the PMs accumulated on the leaves surfaces. Moreover, there was a significant linear relationship between heavy metals contents (Fe, Mn, Zn, Cu, Cr, V and Pb) and magnetic parameters (0.442 ≤ R ≤ 0.799, P < 0.05), which suggested that magnetic parameters of urban park leaves could be used as a proxy for atmospheric heavy metal pollution. The results of multivariate statistical analysis showed that the content of magnetic minerals and heavy metal indust-loaded tree leaves was affected by associated pollution of industry and traffic. PMID:27011970

  10. Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.M.; Zhang, G.L.; Zhang, Y.X.; Li, Y.; Lin, J.; Liu, W.; Cao, Q.C.; Zhao, Y.D.; Ma, C.Y.; Han, Y. [Chinese Academy of Sciences, Shanghai (China). Shanghai Institute of Applied Physics

    2009-11-15

    The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO{sub 4}2{sup -}. It can monitor the sulfur pollution in atmosphere.

  11. Chemical composition and phytotoxicity of volatile essential oil from intact and fallen leaves of Eucalyptus citriodora.

    Science.gov (United States)

    Batish, Daizy R; Singh, Harminder P; Setia, Nidhi; Kaur, Shalinder; Kohli, Ravinder K

    2006-01-01

    A total of 23 volatile constituents was identified and characterized by GC and GC-MS in the volatile essential oil extracted from intact (juvenile and adult) and fallen (senescent and leaf litter) leaves of lemon-scented eucalyptus (Eucalyptus citriodora Hook.). The leaves differed in their pigment, water and protein content, and C/N ratio. The oils were, in general, monoterpenoid in nature with 18 monoterpenes and 5 sesquiterpenes. However, a great variability in the amount of essential oils and their individual constituents was observed in different leaf tissues. The amount was maximum in the senescent leaves collected from the floor of the tree closely followed by that from juvenile leaves. In all, 19 constituents were identified in oil from juvenile and senescent leaves compared to 23 in adult leaves and 20 in leaf litter, respectively. Citronellal, a characteristic monoterpene of the oil reported hitherto was found to be more (77-78%) in the juvenile and senescent leaves compared to 48 and 54%, respectively, in the adult leaves and leaf litter. In the adult leaves, however, the content of citronellol--another important monoterpene-- was very high (21.9%) compared to other leaf types (7.8-12.2%). Essential oil and its two major monoterpenes viz. citronellal and citronellol were tested for their phytotoxicity against two weeds (Amaranthus viridis and Echinochloa crus-galli) and two crops (Triticum aestivum and Oryza sativa) under laboratory conditions. A difference in the phytotoxicity, measured in terms of seedling length and dry weight, of oil from different leaves and major monoterpenes was observed. Oil from adult leaves was found to be most phytotoxic although it occurs in smaller amount (on unit weight basis). The different toxicity of different oil types was due to the relative amount of individual monoterpenes present in the oil, their solubility and interactive action. The study concludes that oil from senescent and juvenile leaves being rich in

  12. RECRUITMENT FINANCED BY SAVED LEAVE (RSL PROGRAMME)

    CERN Multimedia

    Division du Personnel; Tel. 73903

    1999-01-01

    Transfer to the saved leave account and saved leave bonusStaff members participating in the RSL programme may opt to transfer up to 10 days of unused annual leave or unused compensatory leave into their saved leave account, at the end of the leave year, i.e. 30 September (as set out in the implementation procedure dated 27 August 1997).A leave transfer request form, which you should complete, sign and return, if you wish to use this possibility, has been addressed you. To allow the necessary time for the processing of your request, you should return it without delay.As foreseen in the implementation procedure, an additional day of saved leave will be granted for each full period of 20 days remaining in the saved leave account on 31 December 1999, for any staff member participating in the RSL programme until that date.For part-time staff members participating in the RSL programme, the above-mentioned days of leave (annual, compensatory and saved) are adjusted proportionally to their contractual working week as...

  13. Tree Decomposition based Steiner Tree Computation over Large Graphs

    OpenAIRE

    Wei-Kleiner, Fang

    2013-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  15. Concentration change of radiocaesium in persimmon leaves and fruits. Observation results in 2011 Spring - 2013 Summer

    International Nuclear Information System (INIS)

    To make dried-fruits of persimmon (Diospyros kaki), its fresh fruits were generally processed to decrease their water-contents to about 30-50%. During this food process, their radiocaesium concentrations increased without any loss, and, occasionally, the dried-fruits may exceed the food standard level of 100 Bq/kg (edible form). Thus, it is necessary to estimate the radiocaesium concentrations in the products before the fresh fruit harvesting and processing. For this purpose, radiocaesium concentrations in leaves of persimmon trees were monitored with time. The 137Cs concentrations in the fruits were usually lower than those in the leaves and the concentration ratio was less than 0.4 on a fresh weight basis. The ratio became smaller when closer the harvest season. Thus the concentration of leaves could be a good indicator to estimate the processed persimmon fruits. (author)

  16. Tree Diametric Increment and Litterfall Production in an Eastern Amazonian Forest: the Role of Functional Groups

    Science.gov (United States)

    Camargo, P. B. D.; Ferreira, M. L.; Oliveira Junior, R. C.; Saleska, S. R.

    2014-12-01

    Tree growth is a biotic variable of great importance in understanding the dynamics of tree communities and may be used as a tool in studies of biological or climate modeling. Some climate models predict more recurrent climate anomalies in this century, which may alter the functioning of tropical forests with serious structural and demographic implications. The present study aimed to evaluate the profile of tree growth and litterfall production in an eastern Amazon forest, which has suffered recent climatic disturbances. We contrasted different functional groups based on wood density (stem with 0.55; 0.56-0.7; >0.7 g cm-3), light availability (crown illumination index; high illuminated crown - IIC1 until shaded crown - IIC5), and, size class (trees 10-22.5; 22.6-35; 35.1-55; 55,1-90; >90 cm dbh). Tree diameter increment was monthly measured from November 2011 to September 2013 by using dendrometer bands installed on 850 individuals from different families. Litterfall was collected in 64 circular traps, oven dried and weighed, separated into leaves, twigs, reproductive parts and miscellaneous. During the rainy season the sampled trees had the highest rates of tree diametric increment. When analyzing the data by functional groups, large trees had faster growth, but when grouped by wood density, trees with wood density up to 0.55 and between 0.56 and 0.7 g cm-3 had the fastest rates of growth. When grouped by crown illumination index, trees exposed to higher levels of light grew more in comparison to partially shaded trees. Maximum daily air temperature and precipitation were the most important environmental variables in determining the diametric increment profile of the trees. Litterfall production was estimated to be 7.1 Mg ha-1.year-1 and showed a strong seasonal pattern, with dry season production being higher than in the rainy season. Leaves formed the largest fraction of the litterfall, followed by twigs, reproductive parts, and finally miscellaneous. These

  17. Uptake and Translocation of Iron by Native Tree Species In A Constructed Wetland Treating Landfill Leachates

    Directory of Open Access Journals (Sweden)

    A. Snow

    2008-01-01

    Full Text Available A surface flow wetland was constructed in the Burnside Industrial Park, Dartmouth, Nova Scotia, to treat stormwater runoff from the surrounding watersheds which are comprised primarily of commercial properties and two former landfills. The objectives of this study were: (a to compare the uptake of iron by red maple, white birch and red spruce trees growing under flooded soil conditions in the constructed wetland and well drained soil conditions in a nearby reference site, (b to evaluate the seasonal variability of iron in these trees and (c to determine the distribution of iron in different compartments of these trees (leaves, twigs, branches, trunk wood, trunk bark and roots. The average iron concentrations in the aboveground compartments of red maple, white birch and red spruce trees were within the range of iron concentrations reported in the literature for these trees. Red maple, white birch and red spruce trees in the constructed wetland had significantly greater iron concentrations in their roots than the same species in the reference site. The average iron concentrations in the leaves of red maple trees in the constructed wetland and the reference site displayed an increasing trend towards the end of the growing season while the average iron concentrations in the twigs of red maple and white birch trees in the constructed wetland and the reference site displayed maximum concentrations at the beginning of the growing season. Red maple, white birch and red spruce trees in the constructed wetland retained a major portion of their overall iron concentration in their root systems.

  18. Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades

    International Nuclear Information System (INIS)

    Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings (105 μg kg−1) and plant leaves (53 μg kg−1). In addition, Hg concentrations and δ15N values displayed positive correlation in soils influenced by guano. During 1998–2010, estimated annual Hg deposition by guano was 148 μg m−2 yr−1 and ∼8 times the atmospheric deposition. Highlights: • Hg concentrations in the head region of tree islands were the highest. • Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings and plant leaves. • Hg concentrations and δ15N values showed positive correlation in soils influenced by guano. • Estimated annual Hg deposition by guano was 148 μg m−2 yr−1, ∼8 times the atmospheric deposition. -- The annual Hg deposition by bird guano to tree island soils in the Everglades was ∼8 times the atmospheric deposition

  19. Effect of automobile pollution on chlorophyll content of roadside urban trees

    Directory of Open Access Journals (Sweden)

    M. Iqbal

    2015-09-01

    Full Text Available The effect of automobile pollution was determined on chlorophyll content of four different tree species viz. Azadirachta indica L., Conocarpus erectus L., Guiacum officinale L.and Eucalyptus sp. growing along the roads of the city.  Significant changes in the level of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” were found in the leaves of four tree species (A. indica, C. erectus, G.officinale and Eucalyptus sp. collected from polluted sites (Airport, Malir Halt, Quaidabad as compared to control site (Karachi University Campus. Lowest concentration of chlorophyll “a”, chlorophyll “b” and chlorophyll “a+b” was recorded in the leaf samples of all tree species collected from Quaidabad site when compared with the leaf samples collected from control site. The highest levels of chlorophyll pigment were recorded in all tree species leave samples collected from Karachi University Campus.  Similarly, better levels of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” was observed in all tree species growing at Airport site as compared to plants growing at Malir Halt and Quaidabad sites.  This study clearly indicated that the vehicular activities induced air pollution problem and affected on the level of chlorophyll pigments in trees which were exposed to road side pollution.

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

    Science.gov (United States)

    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

  1. On aligning trees

    CERN Document Server

    Calder, J

    1997-01-01

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

  2. Fires on trees

    CERN Document Server

    Bertoin, Jean

    2010-01-01

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

  3. Sweet potato leaves for growing pigs

    OpenAIRE

    An, Le

    2004-01-01

    The aim of the present studies was to evaluate the potential of using sweet potato leaves (Ipomoea batatas (L.) Lam) as a protein source in diets for growing pigs. A number of sweet potato varieties were evaluated with respect to the biomass yield of the leaves, stems and tubers under different leaf harvesting intervals and defoliation techniques with the aim of selecting the best varieties for forage production. The biomass yields of leaves, stems and tubers were found to vary according to v...

  4. Pharmacological Activities of ‘Chandrakhya’ Leaves

    OpenAIRE

    Ashish Singhai; P K Singour; R S Pawar; U K Patil

    2009-01-01

    The herbal drug ‘Chandrakhya’ is commonly used in Indian traditional medicine for thousands of years. Various activities of its rhizome have been reported by several researchers but the studies on leaves are not yet reported. The aim of this study is to explore the analgesic, antibacterial and an antifungal activity of Zingiber officinale (ZO) [Chandrakhya] leaves on albino rats. Aqueous and alcoholic extracts of Zingiber officinale leaves were selected at different doses and analgesic activi...

  5. TREE DECOMPOSITIONS OF MULTIGRAPHS

    Institute of Scientific and Technical Information of China (English)

    SHI Minyong

    1999-01-01

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

  6. 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…

  7. Community tree nursery, Meru, Kenya.

    OpenAIRE

    2006-01-01

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

  8. 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 ...

  9. The supernatural characters and powers of sacred trees in the Holy Land

    Science.gov (United States)

    Dafni, Amots

    2007-01-01

    This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual. PMID:17319970

  10. 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

  11. Fathers on Parental Leave in Denmark

    DEFF Research Database (Denmark)

    Reinicke, Kenneth; Cybulski, Franz Wilhelm; Drews, Lea Vedel;

    2005-01-01

    In the article it is argued that contemporary fatherhood and masculinity differ increasingly from hegemonic masculinity according to which men are primarily responsible for ensuring the financial basis of the family. The article “Fathers on Parental Leave in Denmark”, based on interviews with 15 ......, parental leave and domestic affairs. The article also demonstrates that the issue of parental leave may cause a conflict of interest between an employer and en employee although the majority of employers in this study emphasize that parental leave is unproblematic for them....

  12. Microhabitat heterogeneity across leaves and flower organs promotes bacterial diversity.

    Science.gov (United States)

    Junker, Robert R; Keller, Alexander

    2015-09-01

    Eukaryote-associated microbiomes interact with their hosts in multiple manners, thereby affecting the hosts' phenotype, physical condition and behaviour. In plants, bacteria have numerous functions, with variable net effects, both in natural and agricultural systems. However, information about the composition and diversity of the bacterial communities associated with different aboveground plant organs, particularly flowers, is lacking. In addition, the relative effects of microhabitat and environmental conditions on community establishment require further attention. Here, using culture-independent methods, we determine that leaves and three floral microhabitats (nectar, stamina and styles) of Metrosideros polymorpha (Myrtaceae), a tree endemic to Hawai'i, host unique indicator communities composed of relatively abundant bacterial taxa. These indicator communities are accompanied by a large number of ubiquitous or rare bacteria with lower abundances. In our study system, the strong effect of microhabitat filtering on plant-associated community composition and bacterial richness and diversity strongly exceeds the influence of environmental effects such as precipitation, altitude, substrate age and geographic distance. Thus, the bacterial richness of aboveground plant organs is strongly underestimated when only one microhabitat, e.g. leaves, is considered. Our study represents a first step towards a comprehensive characterization of the distribution, composition and underlying factors, of plant bacterial communities, with implications for future basic and applied research on plant health, pollination and reproduction. PMID:26253507

  13. On the tree packing conjecture

    OpenAIRE

    Balogh, József; Palmer, Cory

    2012-01-01

    The Gy\\'arf\\'as tree packing conjecture states that any set of $n-1$ trees $T_{1},T_{2},..., T_{n-1}$ such that $T_i$ has $n-i+1$ vertices pack into $K_n$. We show that $t=1/10n^{1/4}$ trees $T_1,T_2,..., T_t$ such that $T_i$ has $n-i+1$ vertices pack into $K_{n+1}$ (for $n$ large enough). We also prove that any set of $t=1/10n^{1/4}$ trees $T_1,T_2,..., T_t$ such that no tree is a star and $T_i$ has $n-i+1$ vertices pack into $K_{n}$ (for $n$ large enough). Finally, we prove that $t=1/4n^{1/...

  14. Translocation of radiocesium from stems and leaves of plants and the effect on radiocesium concentrations in newly emerged plant tissues

    International Nuclear Information System (INIS)

    An accident occurred at the Fukushima Dai-ichi Nuclear Power Plant in March 2011 at which time large amounts of radionuclides were released into the atmosphere and the sea. In early May 2011, it was found that newly emerged tea (Camellia sinensis) leaves contained radiocesium, both 134Cs and 137Cs in some areas more than 300 km away from the Fukushima plant. To understand the mechanisms of radiocesium transfer to newly emerged tissues (shoots, leaves and fruits) of other plants in the future, radiocesium concentrations in newly emerged leaves of 14 plant species collected from the sampling areas in and near National Institute of Radiological Sciences in Chiba, Japan. The studied plant types were: (1) herbaceous plants, (2) woody plants with no old leaves at the time of the March accident, and (3) woody plants with old leaves out before the accident. About 40–50 d after the start of the accident, newly emerged leaves from woody plant with old leaves tended to show higher values than other woody or herbaceous plants. Concentrations of radiocesium in newly emerged tissues of trees decreased with time, but they did not decrease to the level of herbaceous plants. The type of the plant and presence of old leaves at the time of the heavy deposition period affected the radiocesium concentrations in newly emerged tissues.

  15. Comparative water relations of mature mahogany (Swietenia macrophylla) trees with and without lianas in a subhumid, seasonally dry forest in Bolivia.

    Science.gov (United States)

    Barker, Martin G.; Pérez-Salicrup, Diego

    2000-11-01

    Many evergreen mahogany (Swietenia macrophylla King) trees in the seasonally dry Bajo Paragua forest in northeast Bolivia carry substantial liana loads. Evergreen lianas may impede the growth of their host trees in various ways, including competition for water. Hypotheses tested were that water relations status differs (a) between lianas and their host trees, and (b) between trees infested with lianas that were cut 3.5 months previously (treated trees) and control trees with intact lianas. Diurnal measurements of stomatal conductance (g(s)) and leaf water potential (Psi) were made on canopy leaves of treated and control trees and lianas at the start and end of the dry season. Lianas had higher (less negative) Psi values (mean and predawn) and higher diurnal g(s) (expressed as mean or sum of diurnal values) than mahogany trees, indicating that lianas had a higher demand for, and ability to obtain, water than their host trees. Control and treated trees had a similar water relations status, suggesting that removal of lianas had no effect on the water relations of the trees, even at the end of the dry season. We conclude that either both life forms have conservative water relations that were unaffected by water availability in our study, or that the trees and lianas have access to sufficient and different sources of water because of differences in their rooting depths. Our data are consistent with studies of temperate species, indicating that lianas do not interfere with water availability to their host trees. PMID:12651492

  16. Ecophysiological studies on photosynthesis and pigment adaptation of light and shade leaves; Oekophysiologische Untersuchungen zur Photosynthese und Pigment-Adaptation bei Licht- und Schattenblaettern

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, M.

    2005-07-01

    Photosynthetic function and pigment adaptation, as well as several other leaf parameters of light and shade adapted leaves of trees were studied under different environmental conditions. These measurements were performed primarily on a solitary standing beech during a summer drought stress period and an autumnal partial regeneration of physiological activity. Mainly investigated were beech leaves, sun leaves growing at the south side of the tree and shade leaves from the interior of the crown, since beech leaves show the strongest physiological light and shade adaptation responses among all deciduous trees. Similar adaptation studies were also performed with red, light-exposed, anthocyanin-containing leaves of the herbaceous purple foliage plant Perilla (beefsteak plant, Chinese basil) and some other plant species with either slightly or more red leaves, in order to check whether the accumulation of anthocyanins in the upper leaf epidermis of sun exposed-leaves blocks the high-light induced formation of sun-type chloroplasts. The latter are known to possess a much higher photosynthetic capacity and a different pigment composition as compared to shade-type chloroplasts of shaded green leaves. Special consideration was given to the natural drought stress effects usually occurring in the summer period (ca. end of July to end of August), caused by a combination of unfavourable weather conditions, such as a longer heat stress, with strong solar radiation and a very low rain precipitation lying clearly below the annual mean. The obtained research results provided new facts for a better understanding of the physiology of photosynthesis in sun and shade leaves of beech at both normal physiological conditions (June) and at environmental stress conditions (July, August), as well as the effect of anthocyanins on the formation of sun-type chloroplasts and their photosynthetic pigments (chlorophylls and carotenoids) in light-exposed purple foliage. (orig.)

  17. Leaf-Associated Bacterial and Fungal Taxa Shifts in Response to Larvae of the Tree Hole Mosquito, Ochlerotatus triseriatus

    OpenAIRE

    Kaufman, Michael G.; Chen, Shicheng; Walker, Edward D

    2008-01-01

    Larvae of the eastern tree hole mosquito, Ochlerotatus triseriatus (Say), and related container-breeding species are known to feed upon substrate-associated microorganisms. Although the importance of these microbial resources to larval growth has been established, almost nothing is known about the taxonomic composition and dynamics of these critical microbial food sources. We examined bacterial and fungal community compositional changes on oak leaves tethered in natural tree hole habitats of ...

  18. Predicting tree crown defoliation using color-infrared orthophoto maps

    Directory of Open Access Journals (Sweden)

    Eigirdas M

    2013-01-01

    Full Text Available Orthophoto maps based on color-infrared aerial photography have been used by the Lithuanian forest inventory since 2001. This study aimed to investigate the opportunities for using these orthophoto maps to predict tree crown defoliation at the single tree and sample plot levels. The test area was located in the Aukstaitija National Park, eastern Lithuania, and it was photographed in the summer of 2008 using a Vexcel UltraCam D digital frame aerial camera to produce digital orthophoto maps with a 0.5 x 0.5 m ground sampling density. Some 1721 tree crowns (mainly pine, spruce and birch, located in 166 permanent sample plots, were identified and delineated on the orthophoto maps. Crown defoliation and other dendrometric characteristics were field-estimated for all of these trees in summer 2008. Judgments on the suitability of using color-infrared aerial photography based orthophotos to estimate tree crown defoliation were based on the accuracy of the defoliation prediction. Defoliation for each crown was predicted using the non-parametric k-Nearest Neighbor (k-NN method and characteristics extracted from the digital orthophoto maps as the auxiliary variables for prediction. Prediction accuracies were validated using the “Leave One Out” technique by comparing the predicted data with data from field-assessed crown defoliations. The lowest root mean square errors for the predicted tree crown defoliation values were 7.564 for pine trees, 9.166 for spruce and 7.712 for birch and the highest coefficients of correlation between field-estimated and predicted crown defoliations were 0.576, 0.600 and 0.386, respectively. However, there was no best performing solution for using the k-NN prediction found, as the best results were achieved using different approaches. Next, predicted and field estimated tree crown defoliation values were aggregated up to the sample plot level by taking an averaging of trees in the same sample plot. The root mean square error

  19. Random self-similar trees and a hierarchical branching process

    CERN Document Server

    Kovchegov, Yevgeniy

    2016-01-01

    We study self-similarity in random binary rooted trees. In a well-understood case of Galton-Watson trees, a distribution is called self-similar if it is invariant with respect to the operation of pruning, which cuts the tree leaves. This only happens in the critical case (a constant process progeny), which also exhibits other special symmetries. We extend the prune-invariance set-up to a non-Markov situation and trees with edge lengths. In this general case the class of self-similar processes becomes much richer and covers a variety of practically important situations. The main result is construction of the hierarchical branching processes that satisfy various self-similarity constraints (distributional, mean, in edge-lengths) depending on the process parameters. Taking the limit of averaged stochastic dynamics, as the number of trajectories increases, we obtain a deterministic system of differential equations that describes the process evolution. This system is used to establish a phase transition that separ...

  20. Recovery of trees from drought depends on belowground sink control.

    Science.gov (United States)

    Hagedorn, Frank; Joseph, Jobin; Peter, Martina; Luster, Jörg; Pritsch, Karin; Geppert, Uwe; Kerner, Rene; Molinier, Virginie; Egli, Simon; Schaub, Marcus; Liu, Jian-Feng; Li, Maihe; Sever, Krunoslav; Weiler, Markus; Siegwolf, Rolf T W; Gessler, Arthur; Arend, Matthias

    2016-01-01

    Climate projections predict higher precipitation variability with more frequent dry extremes(1). CO2 assimilation of forests decreases during drought, either by stomatal closure(2) or by direct environmental control of sink tissue activities(3). Ultimately, drought effects on forests depend on the ability of forests to recover, but the mechanisms controlling ecosystem resilience are uncertain(4). Here, we have investigated the effects of drought and drought release on the carbon balances in beech trees by combining CO2 flux measurements, metabolomics and (13)CO2 pulse labelling. During drought, net photosynthesis (AN), soil respiration (RS) and the allocation of recent assimilates below ground were reduced. Carbohydrates accumulated in metabolically resting roots but not in leaves, indicating sink control of the tree carbon balance. After drought release, RS recovered faster than AN and CO2 fluxes exceeded those in continuously watered trees for months. This stimulation was related to greater assimilate allocation to and metabolization in the rhizosphere. These findings show that trees prioritize the investment of assimilates below ground, probably to regain root functions after drought. We propose that root restoration plays a key role in ecosystem resilience to drought, in that the increased sink activity controls the recovery of carbon balances. PMID:27428669

  1. Accumulation of different metals in apple trees organs from an unfertilized orchard

    International Nuclear Information System (INIS)

    Working in an unfertilized apple orchard, planted on brown-reddish soil in Baneasa - Bucuresti, the accumulation of different metals in trees organs was studied: leaves, vegetative branches, fruit branches and fruits. The samples were taken from 'Golden delicious' variety, planted at 10 meters, 'Idared' variety, planted at 100 meters and 'Akane' variety, planted at 200 meters from the Bucuresti-Ploiesti motorway. Lead accumulation depended on the distance to the pollution source and organ type. In leaves, lead was found even at 100 m from the road border (11.7 ppm in 'Idared' variety). At 10 m the leaves content was much higher (306 ppm, 'Golden delicious'). Because of the specific metabolism selectivity apple trees didn't accumulate lead into fruit branches and fruits. Copper leaves content varied between 5.85 ppm ('Golden delicious') and 16.2 ppm ('Akane') being lower than the fruits content (8.36 ppm 'Idared' - 23.0 ppm 'Golden delicious'). In apple tree fruit branches the Cu accumulation was 2-3 times higher than in the vegetative branches. The same fruit branches accumulated the highest quantity of zinc (between 67.5 and 83.9 ppm). Fruit contents in zinc (10.0-16.9 ppm) were close to the normal value: 15 ppm, but leave contents (43.3-48.7 ppm) were more than doubled compared to the normal range: 15-20 ppm. The 'Idared' variety accumulated the lowest quantity of nickel in all analyzed organs. Iron accumulation was different in function of the analyzed organ, variety and ion type (Fe2+, Fe3+). The highest Fe3+ content was found in 'Golden delicious' leaves: 547 ppm and the highest Fe2+ content in 'Idared' leaves: 96.0 ppm. The lowest iron content was found in fruits. The manganese content of the analyzed organs varied from 8.32 to 130 ppm. Refs. 4 (author)

  2. Leaf morphology of 89 tree species from a lowland tropical rain forest (Atlantic forest) in South Brazil

    OpenAIRE

    Maria Regina Torres Boeger; Luiz Carlos Alves; Raquel Rejane Bonatto Negrelle

    2004-01-01

    We examined the leaf morphology and anatomy of 89 tree species growing in an area of coastal Atlantic Forest in South Brazil. The majority of the species (> 75%) had small (notophyll and microphyll) elliptical simple leaves with entire margins. These leaves presented a typical anatomical structure consisting of a single epidermal cell layer, single palisade parenchyma cell layer, and spongy parenchyma with 5 to 8 cell layers. The sclerenchyma was limited to the vascular bundles. The majority ...

  3. Associational resistance protects mangrove leaves from crab herbivory

    Science.gov (United States)

    Erickson, Amy A.; Bell, Susan S.; Dawes, Clinton J.

    2012-05-01

    While associational defenses have been well documented in many plant and algal ecosystems, this study is the first to document associational resistance in mangroves. Mangrove tree crab (Aratus pisonii) density and herbivory on three life-stages of the red mangrove (Rhizophora mangle) were documented in pure red versus mixed-species and predominantly non-red mangrove stands containing black (Avicennia germinans) and white (Laguncularia racemosa) mangroves in 1999-2000 in Tampa Bay, Florida. This study first established that R. mangle is the focal species in the context of associational resistance because it is damaged more than either of the other mangrove species. Next, it was hypothesized that crab density and leaf damage on R. mangle would be lower when in mixed-species and predominantly non-red versus red mangrove stands. A non-significant trend suggested that crab density varies among stands, and crab damage on R. mangle leaves was significantly lower in mixed-species and non-red stands. Mechanisms to explain associational resistance were examined. Positive Pearson correlations between the percent of adult R. mangle in a stand and both crab density and R. mangle leaf damage provided support for the resource concentration hypothesis. Limited support was found for the attractant-decoy hypothesis because the total amount of damaged leaves of all mangrove species combined typically differed among stands, suggesting that crabs were not shifting to alternative mangrove species to offset reduced availability of R. mangle leaves. Finally, while R. mangle seedlings were shorter in non-red stands compared to others, intra-specific differences in R. mangle leaf chemistry and sclerophylly among stands failed to explain associational patterns. These combined results argue for the need for additional experiments to elucidate mechanisms responsible for defensive plant associations in mangrove ecosystems and to determine whether such associations could be of use in mangrove

  4. Leaf-to-leaf distances in Catalan tree graphs

    OpenAIRE

    Goldsborough, Andrew M.; Fellows, Jonathan M; Bates, Matthew; Rautu, S. Alex; Rowlands, George; Römer, Rudolf A.

    2015-01-01

    We study the average leaf-to-leaf path lengths on ordered Catalan tree graphs with $n$ nodes and show that these are equivalent to the average length of paths starting from the root node. We give an explicit analytic formula for the average leaf-to-leaf path length as a function of separation of the leaves and study its asymptotic properties. At the heart of our method is a strategy based on an abstract graph representation of generating functions which we hope can be useful also in other con...

  5. Nitrogen mineralization in soils under grasses and under trees in a protected Venezuelan savanna

    Science.gov (United States)

    Sánchez, L. F.; García-Miragaya, J.; Chacón, N.

    Nitrogen mineralization was evaluated in soils beneath the most common woody species growing isolated within the grass matrix of a Venezuelan Trachypogon savanna, which has been protected from fire and cattle grazing since 1961. Adult trees of three evergreen species, Byrsonima crassifolia (L) H. B. K., Curatella americana L., and Bowdichia virgilioides H. B. K; and two deciduous, Godmania macrocarpa Hemsley and Cochlospermun vitifolium (Wild) Spreng were selected. The amount of N mineralized (NH 4+-N+NO 3--N) during 15 weeks of laboratory incubation of soils collected from beneath trees, was significantly higher ( p<0.01) than those from under grasses. Values of N mineralized on soil from under trees were from 21.28 to 82.65% greater than for soil from under grasses. A highly significant ( p<0.01) positive correlation, for all soils, was found between Nm and SOC, and between Nm and Nt. The higher N mineralization rates under trees would reflect a higher soil biological activity, due to higher SOC and Nt, of the soils under the tree canopies than those under grasses. The N availability values obtained under all species reveal the importance these trees have for creating enriched areas on generally oligotrophic soils. Nitrogen mineralized in the soil from beneath evergreen trees was significantly ( p<0.01) higher than from under deciduous trees, being 25.87% higher on average. Similarly to the relation found for all soils, a highly significant ( p<0.01) positive correlation between Nm and SOC and between Nm and Nt was also obtained for soils beneath all trees, indicating the importance of SOC and Nt for nitrogen mineralization processes in this savanna. The higher SOC and Nt contents found under evergreen trees are probably due to the longer time they have been established on the site as compared to the deciduous ones. The chemical quality of fresh fallen leaves (as measured by their lignin/nitrogen ratio) did not seem to influence the quality of the SOM (as

  6. Spanning Trees in Random Satisfiability Problems

    OpenAIRE

    Ramezanpour, A.; Moghimi-Araghi, S.

    2005-01-01

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

  7. Static terrestrial laser scanning of juvenile understory trees for field phenotyping

    Science.gov (United States)

    Wang, Huanhuan; Lin, Yi

    2014-11-01

    This study was to attempt the cutting-edge 3D remote sensing technique of static terrestrial laser scanning (TLS) for parametric 3D reconstruction of juvenile understory trees. The data for test was collected with a Leica HDS6100 TLS system in a single-scan way. The geometrical structures of juvenile understory trees are extracted by model fitting. Cones are used to model trunks and branches. Principal component analysis (PCA) is adopted to calculate their major axes. Coordinate transformation and orthogonal projection are used to estimate the parameters of the cones. Then, AutoCAD is utilized to simulate the morphological characteristics of the understory trees, and to add secondary branches and leaves in a random way. Comparison of the reference values and the estimated values gives the regression equation and shows that the proposed algorithm of extracting parameters is credible. The results have basically verified the applicability of TLS for field phenotyping of juvenile understory trees.

  8. Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades.

    Science.gov (United States)

    Zhu, Yingjia; Gu, Binhe; Irick, Daniel L; Ewe, Sharon; Li, Yuncong; Ross, Michael S; Ma, Lena Q

    2014-01-01

    Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg(-1)) were significantly higher than those in mammal droppings (105 μg kg(-1)) and plant leaves (53 μg kg(-1)). In addition, Hg concentrations and δ(15)N values displayed positive correlation in soils influenced by guano. During 1998-2010, estimated annual Hg deposition by guano was 148 μg m(-2) yr(-1) and ~8 times the atmospheric deposition. PMID:24080244

  9. Negotiating leave in the workplace:leave practices and masculinity constructions among Danish fathers

    OpenAIRE

    Bloksgaard, Lotte

    2014-01-01

    In Denmark leave entitlement is not only regulated by law but is also part of the various collective agreements established in the respective occupational sectors and at the local workplace level. Consequently, Danish fathers have very different leave entitlements, depending on the sector, branch and workplace in which they are employed. The paper focuses on fathers’ negotiations of parental leave in three large Danish work places, offering men different opportunities for leave. With a focus ...

  10. 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.

  11. Comparative analysis of antioxidant activity in leaves of different hosts infected by mistletoe (Viscum album L. subsp. album

    Directory of Open Access Journals (Sweden)

    Patykowski Jacek

    2013-01-01

    Full Text Available Studies were performed at different sites in the major city of Lodz (Poland, where mistletoe is particularly abundant. The occurrence of total antioxidant enzyme activities such as superoxide dismutase (SOD, guaiacol peroxidase (POD and the protein and phenol contents in leaves from different hosts infected by European mistletoe (Viscum album L. subsp. album were studied. Some elements may vary in samples from the same mistletoe species on different host trees and species. The most important are changes in the concentration of proteins, including enzyme and stress proteins, in the leaves of trees infected by mistletoe, may indirectly indicate an interaction between host and parasite. There were no important differences in the soluble phenolic content after infection. The change in POD after infection was not significant in comparison to control plants. The SOD activity was significantly higher in leaves from infected trees in comparison to control plants. The obtained data suggest that the increase in SOD and protein content depends mainly on the host taxa. Moreover, we suggest that the main increase in SOD activities in leaves is a consequence of the stress oxidation that caused infection and development of the parasite on the host plant. Chemical analyses of mistletoe from a large sample of host species provide evidence that this parasite may be extremely tolerant to air pollution.

  12. A new class of non-leaves

    CERN Document Server

    Souza, Fábio S

    2011-01-01

    We give examples of open smooth manifolds that cannot be leaves of any Riemannian foliation of arbitrary codimension on a compact manifold. We also present a new class of non-leaves of C^0 codimension one foliations, simply connected manifolds of dimension at least 5 that are non-periodic in homotopy, namely in their 2-dimensional homotopy groups.

  13. A Feminist Perspective on Parental Leave Policies

    Science.gov (United States)

    Sallee, Margaret W.

    2008-01-01

    This article focuses on the ways that three feminist theories--liberal feminism, cultural feminism, and feminist poststructuralism--might be used to craft parental leave policies. After examining each theory in detail, the article concludes by offering one example of an ideal parental leave policy that combines the best features of each theory to…

  14. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Multimedia

    HR Division

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programmes) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave.They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system 1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave...

  15. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Multimedia

    DIVISION HR; TEL. 74474

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programmes) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave. They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system 1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leav...

  16. INTRODUCTION OF A NEW LEAVE MANAGEMENT SYSTEM

    CERN Multimedia

    DIVISION HR

    2000-01-01

    The introduction of new leave rules (arising from the RSL, PRP and other programs) has made the present leave management system rather complicated and difficult to manage. It has therefore been decided to replace it with a more flexible and adaptable system, which will come into force on 1st October 2000. Henceforth, days of leave will be credited monthly instead of annually. Members of the personnel will have round-the-clock direct access to more detailed, confidential information regarding their various kinds of leave. They will also receive a personal monthly statement with their pay slips. The new system does not require any amendment of the regulations, except with respect to the frequency of leave calculations (monthly instead of annual). I. Main characteristics of the new leave system1. The main feature of the new system is the creation of accounts to which leave will be credited or debited as appropriate. Depending on their circumstances, members of the personnel may have up to four individual leave a...

  17. Tree ecophysiological traits related to tree drought mortality are linked to the aridity of the environment in eucalypts

    Science.gov (United States)

    Arndt, S. K.; Sanders, G.; Hirsch, M.

    2013-12-01

    Increases in tree drought mortality are observed in forest ecosystems in all continents but the actual mechanisms how trees succumb to drought are still controversial. Physiological traits and thresholds have often be proposed as possible tools to predict tree drought mortality but these traits and thresholds have only been studied in a few tree species in detail. We investigated the vulnerability to hydraulic cavitation in leaves (P50leaf), turgor loss point (TLP) and osmotic potential at full turgor (OPFT) in 16 different eucalypts species that occur in environments of differing aridity in south-eastern Australia (gradient from 300mm to 1500 mm of precipitation per year). The species were grown from seed, planted in an arboretum in Melbourne and measured under well-watered conditions as two-year old saplings. We observed strong correlations between all measured ecophysiological traits and the aridity of the environment of the origin of the species. P50leaf and TLP were more negative in the eucalypts from more arid environments and more positive in eucalypts from more mesic environments, indicating that eucalypts in arid environments lose turgor at lower water potentials and have a lower vulnerability to hydraulic cavitation in leaves. Eucalypts from arid environments also had a much more negative osmotic potential at full turgor than eucalypts from mesic environments and more rigid cell walls. The measured plants all grew in the same environmental conditions and were well watered at the time of measurement. The results therefore indicate a strong genetic control over these physiological traits in eucalypts - trees from more arid environments lose turgor and hydraulic conductivity at lower water potentials and achieve these lower water potentials by having more osmotically active substances, even if they are not drought stressed. This is the first time these strong correlations between physiological traits and aridity of the origin of the species have been

  18. 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...... 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...

  19. Counting spanning trees in graphs

    OpenAIRE

    Azarija, Jernej

    2012-01-01

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

  20. 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, dynam...... generated instances, approximately 4n FSTs are generated (where n is the number of terminals). The observed running time is quadratic and the FSTs for a 10,000 terminal instance can, on average, be generated within 5 minutes....

  1. Trees Are Useful to Man

    Institute of Scientific and Technical Information of China (English)

    赵明

    2005-01-01

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

  2. Trees as bioindicator of heavy metal pollution in three European cities

    Energy Technology Data Exchange (ETDEWEB)

    Sawidis, T. [Department of Botany, University of Thessaloniki, 54124 Thessaloniki (Greece); Breuste, J., E-mail: juergen.breuste@sbg.ac.at [Department of Geography and Geology, University of Salzburg, 5010 Salzburg (Austria); Mitrovic, M.; Pavlovic, P. [Department of Ecology, Institute for Biological Research ' Sinisa Stankovic' , University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade (Serbia); Tsigaridas, K. [Department of Botany, University of Thessaloniki, 54124 Thessaloniki (Greece)

    2011-12-15

    Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution. - Highlights: > Oriental plane and Austrian pine are suitable for comparative urban air quality biomonitoring of heavy metal pollution. > Pine tree is excellently suitable as urban bioindicator as it accumulates high concentrations of trace metals. > The highest heavy metal pollution was found in Belgrade followed by Thessaloniki and Salzburg. - Oriental plane (Platanus orientalis L.) and Austrian pine (Pinus nigra Arn.), widespread in urban northern and southern Europe, are suitable for comparative biomonitoring of urban air pollution.

  3. Trees as bioindicator of heavy metal pollution in three European cities

    International Nuclear Information System (INIS)

    Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution. - Highlights: → Oriental plane and Austrian pine are suitable for comparative urban air quality biomonitoring of heavy metal pollution. → Pine tree is excellently suitable as urban bioindicator as it accumulates high concentrations of trace metals. → The highest heavy metal pollution was found in Belgrade followed by Thessaloniki and Salzburg. - Oriental plane (Platanus orientalis L.) and Austrian pine (Pinus nigra Arn.), widespread in urban northern and southern Europe, are suitable for comparative biomonitoring of urban air pollution.

  4. Proximate composition and mineral content of two edible species of Cnidoscolus (tree spinach).

    Science.gov (United States)

    Kuti, J O; Kuti, H O

    1999-01-01

    Proximate composition and mineral content of raw and cooked leaves of two edible tree spinach species (Cnidoscolus chayamansa and C. aconitifolius), known locally as 'chaya', were determined and compared with that of a traditional green vegetable, spinach (Spinicia oleraceae). Results of the study indicated that the edible leafy parts of the two chaya species contained significantly (p0.05) differences were found in nutritional composition and mineral content between the chaya species, except minor differences in the relative composition of fatty acids, protein and amino acids. Cooking of chaya leaves slightly reduced nutritional composition of both chaya species. Cooking is essential prior to consumption to inactivate the toxic hydrocyanic glycosides present in chaya leaves. Based on the results of this study, the edible chaya leaves may be good dietary sources of minerals (Ca, K and Fe) and vitamins (ascorbic acid and beta-carotene). PMID:10540979

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

    OpenAIRE

    Pincetl, Stephanie

    2010-01-01

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

  6. The elm, tree of milk and wine

    Directory of Open Access Journals (Sweden)

    Heybroek HM

    2015-04-01

    Full Text Available Elm has played an important role in European culture for thousands of years, in many roles, with regional variation. In material culture, its wood has assisted in hunting and warfare for over seven thousand years; but more importantly, its leaves and bark were semi-indispensible for the production of milk and meat, and served as an emergency food for humans. In the Mediterranean, elm was the main tool for the production of a good quality wine by providing support for the grapevine, and it helped feeding the cattle. These functions sometimes found an echo in the non-material culture. The fact that in Germanic genesis stories the first woman was created out of an elm (the man out of an ash, as well as a severe local taboo on the use of elm wood for skis, threatening the offender with a place in hell, seem both connected to the superior feeding value of this tree. In England and in parts of continental Europe most sacred trees were elms, sometimes performing female functions such as the production of babies. In the Mediterranean, however, the elm was seen as the male partner in the “marriage of the vine to the elm”, which was the celebrated system of viticulture. That image has been used by poets and politicians over the ages to praise the effects of human marriage, cooperation and interdependence. It even forms the core of the apocryphal Bible book “The Shepherd”, where it is seen as a symbol and example for a kind of symbiosis between the rich and the poor. - In conclusion, the ultimate origin of the English elm or “Atinia”, as well as its discovery is discussed, which appears to be a question of milk and wine.

  7. Transpiration of urban trees and its cooling effect in a high latitude city

    Science.gov (United States)

    Konarska, Janina; Uddling, Johan; Holmer, Björn; Lutz, Martina; Lindberg, Fredrik; Pleijel, Håkan; Thorsson, Sofia

    2016-01-01

    An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m-2 s-1 ( B. pendula) to over 3 mmol m-2 s-1 ( Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68 % of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20 % of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m-2, tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m-2, a cooling effect of tree transpiration was not observed during the day.

  8. Independence of stem and leaf hydraulic traits in six Euphorbiaceae tree species with contrasting leaf phenology.

    Science.gov (United States)

    Chen, Jun-Wen; Zhang, Qiang; Li, Xiao-Shuang; Cao, Kun-Fang

    2009-08-01

    Hydraulic traits and hydraulic-related structural properties were examined in three deciduous (Hevea brasiliensis, Macaranga denticulate, and Bischofia javanica) and three evergreen (Drypetes indica, Aleurites moluccana, and Codiaeum variegatum) Euphorbiaceae tree species from a seasonally tropical forest in south-western China. Xylem water potential at 50% loss of stem hydraulic conductivity (P50(stem)) was more negative in the evergreen tree, but leaf water potential at 50% loss of leaf hydraulic conductivity (P50(leaf)) did not function as P50(stem) did. Furthermore, P50(stem) was more negative than P50(leaf) in the evergreen tree; contrarily, this pattern was not observed in the deciduous tree. Leaf hydraulic conductivity overlapped considerably, but stem hydraulic conductivity diverged between the evergreen and deciduous tree. Correspondingly, structural properties of leaves overlapped substantially; however, structural properties of stem diverged markedly. Consequently, leaf and stem hydraulic traits were closely correlated with leaf and stem structural properties, respectively. Additionally, stem hydraulic efficiency was significantly correlated with stem hydraulic resistance to embolism; nevertheless, such a hydraulic pattern was not found in leaf hydraulics. Thus, these results suggest: (1) that the evergreen and deciduous tree mainly diverge in stem hydraulics, but not in leaf hydraulics, (2) that regardless of leaf or stem, their hydraulic traits result primarily from structural properties, and not from leaf phenology, (3) that leaves are more vulnerable to drought-induced embolism than stem in the evergreen tree, but not always in the deciduous tree and (4) that there exists a trade-off between hydraulic efficiency and safety for stem hydraulics, but not for leaf hydraulics. PMID:19495788

  9. Comparison of emissions of biogenic volatile organic compounds from leaves of three tree species

    Czech Academy of Sciences Publication Activity Database

    Holišová, Petra; Večeřová, Kristýna; Pallozi, E.; Guidolotti, G.; Esposito, R.; Calfapietra, Carlo; Urban, Otmar

    Brno: Global Change Research Centre, The Czech Academy of Sciences, v. v. i., 2015 - (Urban, O.; Šprtová, M.; Klem, K.), s. 126-129 ISBN 978-80-87902-10-3. [Global Change: A Complex Challenge /4th/. Brno (CZ), 23.03.2015-24.03.2015] R&D Projects: GA MŠk(CZ) LD13031; GA MŠk(CZ) LO1415; GA MŠk EE2.3.20.0246; GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67179843 Keywords : emissions * chemical reactivity * plants * BVOC * Norway spruce Subject RIV: EF - Botanics

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

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

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

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

    Science.gov (United States)

    Pincetl, Stephanie

    2010-02-01

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

  12. Arrangement Analysis of Leaves Optimized on Photon Flux Density or Photosynthetic Rate

    Science.gov (United States)

    Obara, Shin'ya; Tanno, Itaru

    By clarifying a plant evolutive process, useful information may be obtained on engineering. Consequently, an analysis algorithm that investigates the optimal arrangement of plant leaves was developed. In the developed algorithm, the Monte Carlo method is introduced and sunlight is simulated. Moreover, the arrangement optimization of leaves is analyzed using a Genetic Algorithm (GA). The number of light quanta (photon flux density) that reaches leaves, or the average photosynthetic rate of the same was set as the objective function, and leaf models of a dogwood and a ginkgo tree were analyzed. The number of leaf models was set between two to four, and the position of the leaf was expressed in terms of the angle of direction, elevation angle, rotation angle, and the representative length of the branch of a leaf. The chromosome model introduced into GA consists of information concerning the position of the leaf. Based on the analysis results, the characteristics of the leaf of an actual plant could be simulated by ensuring the algorithm had multiple constrained conditions. The optimal arrangement of leaves differs in maximization of the photon flux density, and that of the average value of a photosynthetic rate. Furthermore, the leaf form affecting the optimal arrangement of leave and also having a significant influence also on a photosynthetic rate was shown.

  13. Elevated ozone negatively affects photosynthesis of current-year leaves but not previous-year leaves in evergreen Cyclobalanopsis glauca seedlings

    International Nuclear Information System (INIS)

    To assess the effects of leaf age/layer on the response of photosynthesis to chronic ozone (O3), Cyclobalanopsis glauca seedlings, a dominant evergreen broadleaf tree species in sub-tropical regions, were exposed to either ambient air (AA) or elevated O3 (AA + 60 ppb O3, E-O3) for two growing seasons in open-top chambers. Chlorophyll content, gas exchange and chlorophyll a fluorescence were investigated three times throughout the 2nd year of O3 exposure. Results indicated that E-O3 decreased photosynthetic parameters, particularly light-saturated photosynthesis rate, stomatal conductance and effective quantum yield of PSII photochemistry of current-year leaves but not previous-year leaves. Stomatal conductance of plants grown under ambient conditions partially contributed to the different response to E-O3 between leaf layers. Light radiation or other physiological and biochemical processes closely related to photosynthesis might play important roles. All suggested that leaf ages or layers should be considered when assessing O3 risk on evergreen woody species. -- Highlights: • Response of evergreen Cyclobalanopsis glauca to O3 was investigated. • Elevated O3 significantly reduced photosynthesis of current-year leaves. • Previous-year leaves showed little response to O3. • Stomatal conductance contributes to the response difference to O3 among leaf ages. -- Impacts of elevated O3 on photosynthesis of evergreen woody species depend on leaf ages

  14. Correlations between canopy gaps and species diversity in broad-leaved and Korean pine mixed forests

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiuhai; ZHANG Chunyu; ZHENG Jingming

    2006-01-01

    Regeneration of tree species associated with canopy gaps in broad-leaved Korean pine forests was investigated.Species diversity in gaps and under closed canopy was compared,the relationship between biodiversity and gap structure was analyzed.Results indicate that there were significant differences between tree species diversity in gaps and that under canopy (p<0.01).In terms of Shannon-Wiener index,evenness index,and abundance index,the biodiversity in gap community were higher than those under forest canopy in regeneration layer.In terms of Simpson's dominance index,the dominance of certain species in the regeneration layer increased from gaps to closed canopy (p<0.01).In contrast,trends of biodiversity changes of succession layer in gaps and under closed canopy were opposite.Tree species diversity of different layers reacted directly to the change of gap size class.For example,Shannon-Wiener index and abundance index is higher and Simpson's dominance index is the lowest in succession layer of medium-size gap (100-250 m2) in the broad-leaved Korean pine forest of Changbai Mountains.Shannon-Wiener index reached the highest in a size of≥250 m2 and<100 m2,reached the lowest in a size of 200-250 m2 in the regeneration layer.Simpson's dominance index reached its maximum when the gap size was between 200 and 250m2.Generally,species of different layers reacted differently to the changes of gap size classes.The gap size class with more seedlings did not correspond to size class containing more medium-size trees.Tree species diversity indices in the two layers behaved reciprocally during the development process of forest gaps.

  15. Changes in the delta 13C values of trees during a tropical rainy season: some effects in addition to diffusion and carboxylation by Rubisco?

    International Nuclear Information System (INIS)

    The delta 13C values of deciduous and evergreen tree leaves were compared in open and closed- canopy environments throughout a rainy season in Panama. Newly emerging leaves had higher delta 13C values than older leaves of all seedlings and trees al all dates sampled. This was apparently not caused by a decline in water use efficiency as leaves develop because instantaneous ci/ca was significantly higher in newly emerging than in expanded leaves on the same twigs of trees in the field as well as on seedlings growing in a controlled, unchanging environment. Higher delta 13C values in newly emerging leaves occurred across diverse environmental comparisons. For example, leaves emerging during the rainy season had higher delta 13C values than corresponding mature leaves that had emerged both during the dry season and when water was abundant. The early enrichment in 13C may thus reflect the translocation of carbon to initiate a new leaf. Furthermore, the lack of sensitivity of this enrichment to a microclimate suggests that it might be the result of processes that occur after carbon fixation by Rubisco. Other changes in delta 13C values as leaves developed may also have resulted from carbon translocation processes. Foliar delta 13C decreased significantly after most of the leaf biomass of the deciduous Apeiba membranacea had developed. The delta 13C values of the evergreen Cecropia insignia were lower in the open canopy than in closed-canopy forests at the end of the rainy season. These findings suggest that the delta 13C values of leaves can yield ecological information about the allocation of carbon within trees

  16. Evaluation of forest trees growth after sewage sludge application

    Science.gov (United States)

    Vaitkutä--, Dovilé; Balträ--Naitä--, Edita; Booth, Colin A.; Fullen, Michael A.; Pereira, Paulo

    2010-05-01

    Sewage sludge is extensively used in forest to improve soil properties. It is expected that sewage sludge rich in phosphorus, nitrogen and organic material enhance the germination of tree seedlings in poor soils. In Lithuania, the deforested soils are highly acid, and have a lack of nutrients, especially in exploited peat areas. Sewage sludge from industry contains beneficial components for the soils (such as organic matter, phosphorus, nitrogen, calcium, magnesium, etc.). However, it is also rich in heavy metals, especially Cd, Pb, Cu and Zn. High heavy metals concentrations in soil can be phytotoxic and cause reduced plant growth or plant death. The main objectives of this research was to determine the influence of industrial sewage sludge in the forestry and to highlight the idea that industrial sewage sludge containing metals does not favour development of birch and pine trees. The study was performed in Taruskos experimental plot in Panevezys region (Lithuania), amended with industrial sewage sludge ten years ago was afforestated with birch and pine seedlings. In order to observe the effects of the amendment in accumulation the mentioned metals and tree growth we collected data from trees in amended plot and control plot. The results showed that soil parameters were improved in the amended plot, in comparing with control site (higher pH, organic matter and cation exchange capacity). However, the growth of investigated trees was slower (e.g. birch roots, shoot, stem and leaves biomass was 40, 7.4, 18.6, 22% smaller than in control site. In pine case: 30, 1.2, 17, 36%, respectively; the stem height of birch was 16% and pine - 12% smaller than in control site). This reduced growth can be related with heavy metals concentration load on soil and accumulation in trees. Cu and Cd concentrations were higher in soil amended with sewage sludge comparing with control site (60 and 36%, respectively). Also, in contaminated trees Cu and Cd concentrations were higher (Cu

  17. 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...... and their knowledge bases. The paper is inspired by molecular biology, where phylogenies of biological life are reconstructed by means of extremely rich genomic data and powerful computer algorithms. The paper suggests that input-output data can be used as a first source of reconstructing industrial...... 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....

  18. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

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

  19. Efficient Frequent Pattern Tree Construction

    Directory of Open Access Journals (Sweden)

    D.Bujji Babu

    2014-03-01

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

  20. 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.

  1. Quantum Simulation of Phylogenetic Trees

    OpenAIRE

    Ellinas, Demosthenes; Jarvis, Peter

    2011-01-01

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

  2. Classifying melodies using tree grammars

    OpenAIRE

    Bernabeu Briones, José Francisco; CALERA RUBIO, JORGE; Iñesta Quereda, José Manuel

    2011-01-01

    Similarity computation is a difficult issue in music information retrieval, because it tries to emulate the special ability that humans show for pattern recognition in general, and particularly in the presence of noisy data. A number of works have addressed the problem of what is the best representation for symbolic music in this context. The tree representation, using rhythm for defining the tree structure and pitch information for leaf and node labeling has proven to be effective in melodic...

  3. Temperature profile in apricot tree canopies under the soil and climate conditions of the Romanian Black Sea Coast

    Science.gov (United States)

    Paltineanu, Cristian; Septar, Leinar; Chitu, Emil

    2016-03-01

    The paper describes the temperature profiles determined by thermal imagery in apricot tree canopies under the semi-arid conditions of the Black Sea Coast in a chernozem of Dobrogea Region, Romania. The study analyzes the thermal vertical profile of apricot orchards for three representative cultivars during summertime. Measurements were done when the soil water content (SWC) was at field capacity (FC) within the rooting depth, after intense sprinkler irrigation applications. Canopy temperature was measured during clear sky days at three heights for both sides of the apricot trees, sunlit (south), and shaded (north). For the SWC studied, i.e., FC, canopy height did not induce a significant difference between the temperature of apricot tree leaves (Tc) and the ambient air temperature (Ta) within the entire vertical tree profile, and temperature measurements by thermal imagery can therefore be taken at any height on the tree crown leaves. Differences between sunlit and shaded sides of the canopy were significant. Because of these differences for Tc-Ta among the apricot tree cultivars studied, lower base lines (LBLs) should be determined for each cultivar separately. The use of thermal imagery technique under the conditions of semi-arid coastal areas with low range of vapor pressure deficit could be useful in irrigation scheduling of apricot trees. The paper discusses the implications of the data obtained in the experiment under the conditions of the coastal area of the Black Sea, Romania, and neighboring countries with similar climate, such as Bulgaria and Turkey.

  4. 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

  5. Adaptive Responses of Birch-Leaved Pear (Pyrus betulaefolia Seedlings to Salinity Stress

    Directory of Open Access Journals (Sweden)

    Qiang Sheng WU

    2009-06-01

    Full Text Available One-year-old birch-leaved pear (Pyrus betulaefolia Bunge seedlings were subjected to 0, 50, 100, 150, and 200 mmol/L NaCl solutions for 27 days in order to study the effects of salinity stress on photosynthesis, ion accumulation and enzymatic and non-enzymatic scavenging of reactive oxygen species in the seedlings. The research was performed in a greenhouse using potted trees. Salinity stress reduced photosynthetic rates, stomatal conductance and water use efficiency of leaves of the pear seedlings, but increased transpiration rates and leaf temperature. Hydrogen peroxide and superoxide anion radical contents increased with increasing NaCl concentrations, a phenomena also observed for malondialdehyde, suggesting that leaves of the pear seedlings suffered from oxidative injury. Superoxide dismutase (SOD and catalase (CAT activities quickly responded by increasing when the pear seedlings were subjected to salinity stress. Total protein content in leaves of the seedlings was restrained by salinity stress, whereas ascorbate content increased. Salinity stress reduced glutathione content once the birch-leaved pear seedlings were exposed to a low level (50 or 100 mmol/L of NaCl, whereas a high level (150 or 200 mmol/L NaCl of salinity stress stimulated the accumulation of glutathione. Salinity stress increased the accumulation of Na+, Cl-, K+ and Mg2+ in the seedlings, but reduced Ca2+ levels and the ratio of other ions to Na+ except K+/Na+ under 50 mmol/L NaCl conditions. This suggests that leaves of birch-leaved pear seedlings possess the capacity for salt exclusion only under 50 mmol/L NaCl conditions, and Ca2+ does not play a fundamental role as a secondary messenger under salinity stress conditions.

  6. Methods of Foliar Surface Determination along the Ontogenetic Cycle on Apple Trees

    Directory of Open Access Journals (Sweden)

    Valerian BALAN

    2010-12-01

    Full Text Available This study aimed at determining the evolution of foliar surface in different types of annual branches of apple using different methods of foliar surface determination. The investigations were carried out in the intensive orchard of Didactic Experimental Station Criuleni, Moldavia. The observations were made on the cultivar Golden Delicious grafted on an M4 rootstock, and planted at 5 x 3 m distances, along the main four periods of ontogenetic cycle (growth, growth and fructification, fructification and growth, fructification. The trees were formed by the free growing palmette type. The leaf surface area was determined for all trees considered through measuring and numbering. In order to determine the dimension of the foliar surface, all types of annual shoots were measured. In addition, the quantity of leaves on the annual shoots and on the spurs was determined. Using the existing data, the leaf surface area for tree and area unit was calculated. Leaf area in the trees, during ontogenesis, was 3.26-29.9 m/tree, respectively 2.1-10.92 m/tree on the shoots and 1.16-23.7 m/tree on the spurs, spears and old spur systems.

  7. Generic physical protection logic trees

    International Nuclear Information System (INIS)

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

  8. 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.

  9. Objective consensus from decision trees

    International Nuclear Information System (INIS)

    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

  10. Layered Working-Set Trees

    CERN Document Server

    Bose, Prosenjit; Dujmović, Vida; Howat, John

    2009-01-01

    The working-set bound [Sleator and Tarjan, J. ACM, 1985] roughly states that searching for an element is fast if the element was accessed recently. Binary search trees, such as splay trees, can achieve this property in the amortized sense, while data structures that are not binary search trees are known to have this property in the worst case. We close this gap and present a binary search tree called a layered working-set tree that guarantees the working-set property in the worst case. The unified bound [Badoiu et al., TCS, 2007] roughly states that searching for an element is fast if it is near (in terms of rank distance) to a recently accessed element. We show how layered working-set trees can be used to achieve the unified bound to within a small additive term in the amortized sense while maintaining in the worst case an access time that is both logarithmic and within a small multiplicative factor of the working-set bound.

  11. Identification of major backscattering sources in trees and shrubs at 10 GHz

    Science.gov (United States)

    Zoughi, R.; Wu, L. K.; Moore, R. K.

    1986-01-01

    A short-range very-fine-resolution FM-CW radar scatterometer has been used to identify the primary contributors to 10-GHz radar backscatter from pine, pin oak, American sycamore and sugar maple trees, and from creeping juniper shrubs. This system provided a range resolution of 11 cm and gave a 16-cm diameter illumination area at the target range of about 4 m. For a pine tree, the needles caused the strongest backscatter as well as the strongest attenuation in the radar signal. Cones, although insignificant contributors to the total backscatter, were more important for backscattering than for attenuation. For the rest of the trees, leaves were the strongest cause of backscattering and attenuation. However, in the absence of leaves, the petioles, small twigs, and branches gave relatively strong backscatter. For American sycamore and sugar maple trees, the fruits did not affect the total backscatter unless they were packed in clusters. For creeping juniper the backscattered energy and attenuation in the radar signal were mainly due to the top two layers of the evergreen scales. The contribution of the tree trunks was not determined.

  12. Variability of morphometric characteristics of the leaves of European white elm from the area of Great War Island

    Directory of Open Access Journals (Sweden)

    Devetaković Jovana

    2013-01-01

    Full Text Available The European White Elm (Ulmus effusa Willd. is indicated as a rare and endangered species in the growing stock of the Republic of Serbia. In the area of Great War Island, its natural populations were reduced to 56 registered trees, which occur in three spatially isolated subpopulations. On the basis of the research conducted on the level of variability of adaptible morphometric characteristics of leaves from 14 selected test trees of European White Elm, it can be concluded that the degree of interpopulation variability is satisfactory, which is a good basis for the conservation of the available gene pool.

  13. Carbon isotope composition of latex does not reflect temporal variations of photosynthetic carbon isotope discrimination in rubber trees (Hevea brasiliensis).

    Science.gov (United States)

    Kanpanon, Nicha; Kasemsap, Poonpipope; Thaler, Philippe; Kositsup, Boonthida; Gay, Frédéric; Lacote, Régis; Epron, Daniel

    2015-11-01

    Latex, the cytoplasm of laticiferous cells localized in the inner bark of rubber trees (Hevea brasiliensis Müll. Arg.), is collected by tapping the bark. Following tapping, latex flows out of the trunk and is regenerated, whereas in untapped trees, there is no natural exudation. It is still unknown whether the carbohydrates used for latex regeneration in tapped trees is coming from recent photosynthates or from stored carbohydrates, and in the former case, it is expected that latex carbon isotope composition of tapped trees will vary seasonally, whereas latex isotope composition of untapped trees will be more stable. Temporal variations of carbon isotope composition of trunk latex (δ(13)C-L), leaf soluble compounds (δ(13)C-S) and bulk leaf material (δ(13)C-B) collected from tapped and untapped 20-year-old trees were compared. A marked difference in δ(13)C-L was observed between tapped and untapped trees whatever the season. Trunk latex from tapped trees was more depleted (1.6‰ on average) with more variable δ(13)C values than those of untapped trees. δ(13)C-L was higher and more stable across seasons than δ(13)C-S and δ(13)C-B, with a maximum seasonal difference of 0.7‰ for tapped trees and 0.3‰ for untapped trees. δ(13)C-B was lower in tapped than in untapped trees, increasing from August (middle of the rainy season) to April (end of the dry season). Differences in δ(13)C-L and δ(13)C-B between tapped and untapped trees indicated that tapping affects the metabolism of both laticiferous cells and leaves. The lack of correlation between δ(13)C-L and δ(13)C-S suggests that recent photosynthates are mixed in the large pool of stored carbohydrates that are involved in latex regeneration after tapping. PMID:26358051

  14. Urban warming drives insect pest abundance on street trees.

    Science.gov (United States)

    Meineke, Emily K; Dunn, Robert R; Sexton, Joseph O; Frank, Steven D

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer. PMID:23544087

  15. Urban warming drives insect pest abundance on street trees.

    Directory of Open Access Journals (Sweden)

    Emily K Meineke

    Full Text Available Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

  16. Effective Tree Scattering at L-Band

    Science.gov (United States)

    Kurum, Mehmet; ONeill, Peggy E.; Lang, Roger H.; Joseph, Alicia T.; Cosh, Michael H.; Jackson, Thomas J.

    2011-01-01

    For routine microwave Soil Moisture (SM) retrieval through vegetation, the tau-omega [1] model [zero-order Radiative Transfer (RT) solution] is attractive due to its simplicity and eases of inversion and implementation. It is the model used in baseline retrieval algorithms for several planned microwave space missions, such as ESA's Soil Moisture Ocean Salinity (SMOS) mission (launched November 2009) and NASA's Soil Moisture Active Passive (SMAP) mission (to be launched 2014/2015) [2 and 3]. These approaches are adapted for vegetated landscapes with effective vegetation parameters tau and omega by fitting experimental data or simulation outputs of a multiple scattering model [4-7]. The model has been validated over grasslands, agricultural crops, and generally light to moderate vegetation. As the density of vegetation increases, sensitivity to the underlying SM begins to degrade significantly and errors in the retrieved SM increase accordingly. The zero-order model also loses its validity when dense vegetation (i.e. forest, mature corn, etc.) includes scatterers, such as branches and trunks (or stalks in the case of corn), which are large with respect to the wavelength. The tau-omega model (when applied over moderately to densely vegetated landscapes) will need modification (in terms of form or effective parameterization) to enable accurate characterization of vegetation parameters with respect to specific tree types, anisotropic canopy structure, presence of leaves and/or understory. More scattering terms (at least up to first-order at L-band) should be included in the RT solutions for forest canopies [8]. Although not really suitable to forests, a zero-order tau-omega model might be applied to such vegetation canopies with large scatterers, but that equivalent or effective parameters would have to be used [4]. This requires that the effective values (vegetation opacity and single scattering albedo) need to be evaluated (compared) with theoretical definitions of

  17. Labour Supply Responses to Paid Parental Leave

    OpenAIRE

    Karimi, Arizo; Lindahl, Erica; Skogman Thoursie, Peter

    2012-01-01

    Women account for the majority of parental leave take-up, which is likely one of the major reasons for the gender gap in income and wages. Consequently, many countries exert effort to promote a more gender equal division of parental leave. Indeed, the last decades have seen an increase in fathers’ take-up of parental leave benefits, but the gender earnings gap has remained fairly constant. In this paper we re-evaluate the labour supply responses of both mothers and fathers to three major refo...

  18. Phenolic profile of Cydonia oblonga Miller leaves

    OpenAIRE

    Andreia P. Oliveira; Pereira, J.A.; Andrade, P.B.; Valentão, P.; Seabra, R.M.; B.M. Silva

    2007-01-01

    Cydonia oblonga Miller leaves phenolic compounds were analyzed by reversed-phase HPLC/DAD and HPLC/UV. Qualitative and quantitative analysis of phenolics were carried out in a total of 36 samples of quince leaves from three different geographical origins of Northern (Bragança and Carrazeda de Ansiães) and Central Portugal (Covilhã) and three collection months (June, August, and October of 2006). These leaves presented a common phenolic profile composed by nine compounds: 3-O-, 4-O...

  19. Laser induced fluorescence of some plant leaves

    International Nuclear Information System (INIS)

    Laser induced fluorescence (LIF) is successfully used as a technique for remote detection of spectral characteristics of some plants. A pulsed nitrogen laser at 337.1 nm is used to excite cotton, corn and rice leaves. The fluorescence spectrum is detected in the range from 340 nm to 820 nm. It is found that, these plant leaves have common fluorescence maxima at 440 nm, 685 nm and 740 nm. plant leaves are also found to be identifiable by the ratio of the fluorescence intensity at 440 nm to that at 685 nm. The present technique can be further used as a means of assessing, remotely, plant stresses. 5 fig

  20. 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 ...... complexity of our algorithm makes the method of refined Buneman trees computational competitive to methods based on neighbor joining....