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Sample records for hybrid poplar barely

  1. Biomass and nitrogen dynamics in an irrigated hybrid poplar plantation

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, R.A.

    1985-01-01

    A 3-year study measured the effects of ground cover treatments and nitrogen fertilization on biomass and nitrogen dynamics in an irrigated hybrid poplar (Populus deltoides Bartr. x P. trichocarpa Torr. and Gray, clone NC-9922) plantation in northern Wisconsin. Annually fertilized (112 kg N/ha/yr) and unfertilized plots were either maintained weed-free (bare soil), allowed to revegetate with native weeds, or seeded to birdsfoot trefoil (Lotus corniculatus L.). Trees in bare soil plots responded to fertilization primarily in the third growing season, but total biomass of 3-year-old trees was not increased by annual fertilization. High nitrate-nitrogen concentrations in the soil solution suggested significant leaching in both unfertilized and fertilized bare soil plots in the first growing season, and in fertilized plots the second season. Nitrate-nitrogen concentrations declined sharply in fertilized bare soil plots during the third growing season. Cover crop biomass was greatest in the second year and declined thereafter due to declines in below-ground components. Fertilization increased tree growth in these plots, but cover crop treatments had no effect. Results of this study suggest that, under irrigated conditions, a cover crop can substantially reduce leaching losses of nutrients and serve as a slow-release pool of nitrogen after the trees achieve crown closure. Fertilization is not recommended in these plantations until the second growing season if a cover crop is present and the third growing season if complete weed control is practiced.

  2. Use of Sulfometuron in Hybrid Poplar Energy Plantations

    Science.gov (United States)

    Daniel A. Netzer

    1995-01-01

    Reports that low rates of sulfometuron, 70 grams per hactare (1 ounce product or 0.75 ounces active ingredient per acre), applied when hybrid poplars are completely dormant, can provide season-long weed control and increase hybrid poplar growth. If plantation access is not possible before growth activity begins in the spring, late fall application of this herbicide...

  3. DIMENSIONAL STABILITY OF METHYL METHACRYLATE HARDENED HYBRID POPLAR WOOD

    Directory of Open Access Journals (Sweden)

    Wei-Dan Ding,

    2011-11-01

    Full Text Available This study examines the dimensional stability of fast-growing poplar clones wood after treatment by impregnation with methyl methacrylate (MMA. Six hybrid poplar clones from one plantation in Quebec were sampled. The effects of hardening with MMA on density as well as longitudinal, radial, tangential, and volumetric swelling properties (S, water uptake capacity (D, anti-swelling efficiency (ASE, and water repellent efficiency (WRE after soaking were investigated. Hardening treatment increased the density of all poplar woods by 1.2 to 1.6 and decreased the inner water migration rate during soaking. S and D values of hardened woods were significantly lower than those of controls, depending on the clone type. ASE and WRE values suggested that incorporating MMA effectively improved the dimensional stability of poplar wood at the early soaking stage, but was less effective in the long term.

  4. Co-pyrolysis of different type coals with hybrid poplar

    Energy Technology Data Exchange (ETDEWEB)

    Hanzade Haykiri-Acma; Serdar Yaman [Istanbul Technical University, Istanbul (Turkey). Dept. of Chemical Engineering

    2007-07-01

    The aim of this study is to investigate the co-pyrolysis characteristics of different rank coals such as peat, lignite, and anthracite in the presence of hybrid poplar. For this purpose, non-isothermal thermogravimetry technique was applied up to 900{sup o}C with a heating rate of 40{sup o}C/min under dynamic nitrogen flow of 40 mL/min. Hybrid poplar was added into each coal as much as 10 wt % of the coal sample and the experiments were repeated. Pyrolytic properties such as the char yields, gasification rates, and reactivity of the original samples and the blends were compared from the thermal analysis data, and interpreted. Addition of hybrid poplar to coal had some influences on the pyrolytic properties of coals that might be explained by the synergistic interaction approach. 15 refs., 3 figs., 4 tabs.

  5. Economic investigations of short rotation intensively cultured hybrid poplars

    Science.gov (United States)

    David C. Lothner

    1983-01-01

    The history of the economic analyses is summarized for short rotation intensively cultured hybrid poplar at the North Central Forest Experiment Station. Early break-even analyses with limited data indicated that at a price of $25-30 per dry ton for fiber and low to medium production costs, several systems looked profitable. Later cash flow analyses indicated that two...

  6. Summer is the best time to thin hybrid poplar plantations

    Science.gov (United States)

    Harold F. Ford; Albert G., Jr. Snow

    1954-01-01

    Hybrid poplar plantations are established by planting dormant cuttings in close spacing, usually 4 x 4 feet. They are cultivated during the first growing season to eliminate competition from grasses and weeds. After the first year, the more vigorous trees effectively shade out lower vegetation. But rapid tree growth often makes thinning necessary after 2 or 3 growing...

  7. Seedling test and genetic analysis of white poplar hybrid clones

    Institute of Scientific and Technical Information of China (English)

    LI Bo; JIANG Xi-bing; ZHANG You-hui; ZHANG Zhi-yi; LI Shan-wen; AN Xin-min

    2008-01-01

    Cross breeding strategies are very efficient for gaining new and superior genotypes. Ninety-eight new white poplar hybrid clones produced from 12 cross combinations within the Section Leuce Duby were studied using genetic analysis and seedling tests. We exploited the wide variation that exists in this population and found that the differences among diameter at breast height (DBH), root collar diameter (RCD) and height (H) were statistically extremely significant. The repeatability of clones of these measured traits ranged from 0.947-0.967, which indicated that these Waits were strongly controlled by genetic factors. Based on multiple comparisons, a total of 25 clones showed better performance in growth than the conlrol cultivar. These 25 clones were from six different cross combinations, which can guarantee a larger genetic background for future new clone promotion projects. This study provides a simple overview on these clones and can guide us to carry out subsequent selection plans.

  8. Aboveground dendromass allometry of hybrid black poplars for energy crops

    Directory of Open Access Journals (Sweden)

    Tatiana Stankova

    2016-06-01

    Full Text Available Cultivation of energy crops is concerned with estimation of the total lignified biomass (dendromass production, which is based on the plantation density and individual plant dendromass. The main objective of this study was to investigate the allometry of aboveground leafless biomass of juvenile black poplar hybrids (Populus deltoides x P. nigra , traditionally used for timber and cellulose production, and to derive generic allometric models for dendromass prediction, relevant to energy crop cultivation in Bulgaria. The study material comprised a variety of growth sites, tree ages and clones, specific to poplar plantings in Bulgaria. We used three principal quantitative predictors: diameter at breast height, total tree height and mean stand (stock height. The models were not differentiated by clone, because the black poplar hybrids tested were not equally represented in the data, and the inclusion of tree age as a predictor variable seemed unreliable, because of the significant, up to 3 years, variation, which was possible within the narrow age range investigated. We defined the mean stand (stock height as a composite quantitative variable, which reflected the interaction between the time since planting (age, site quality and the intrinsic growth potential. Stepwise and backward multiple regression analyses were applied to these quantitative variables and their products and sets of adequacy and goodnessof-fit criteria were used to derive individual biomass models for stem and branches. Then we developed compatible additive systems of models for stem, branch and total lignified biomass in log-transformed form. Finally, the prediction data were back-transformed, applying correction for bias, and were cross-validated. Three systems of generic equations were derived to enable flexible model implementation. Equation system M1 proposes a stem biomass model based on tree and stand heights and stem diameter, and a model for

  9. Aboveground dendromass allometry of hybrid black poplars for energy crops

    Directory of Open Access Journals (Sweden)

    Tatiana Stankova

    2016-06-01

    Full Text Available Cultivation of energy crops is concerned with estimation of the total lignified biomass (dendromass production, which is based on the plantation density and individual plant dendromass. The main objective of this study was to investigate the allometry of aboveground leafless biomass of juvenile black poplar hybrids (Populus deltoides x P. nigra , traditionally used for timber and cellulose production, and to derive generic allometric models for dendromass prediction, relevant to energy crop cultivation in Bulgaria. The study material comprised a variety of growth sites, tree ages and clones, specific to poplar plantings in Bulgaria. We used three principal quantitative predictors: diameter at breast height, total tree height and mean stand (stock height. The models were not differentiated by clone, because the black poplar hybrids tested were not equally represented in the data, and the inclusion of tree age as a predictor variable seemed unreliable, because of the significant, up to 3 years, variation, which was possible within the narrow age range investigated. We defined the mean stand (stock height as a composite quantitative variable, which reflected the interaction between the time since planting (age, site quality and the intrinsic growth potential. Stepwise and backward multiple regression analyses were applied to these quantitative variables and their products and sets of adequacy and goodnessof-fit criteria were used to derive individual biomass models for stem and branches. Then we developed compatible additive systems of models for stem, branch and total lignified biomass in log-transformed form. Finally, the prediction data were back-transformed, applying correction for bias, and were cross-validated. Three systems of generic equations were derived to enable flexible model implementation. Equation system M1 proposes a stem biomass model based on tree and stand heights and stem diameter, and a model for

  10. Genetic variation of hydraulic and wood anatomical traits in hybrid poplar and trembling aspen.

    Science.gov (United States)

    Schreiber, Stefan G; Hacke, Uwe G; Hamann, Andreas; Thomas, Barb R

    2011-04-01

    Intensive forestry systems and breeding programs often include either native aspen or hybrid poplar clones, and performance and trait evaluations are mostly made within these two groups. Here, we assessed how traits with potential adaptive value varied within and across these two plant groups. Variation in nine hydraulic and wood anatomical traits as well as growth were measured in selected aspen and hybrid poplar genotypes grown at a boreal planting site in Alberta, Canada. Variability in these traits was statistically evaluated based on a blocked experimental design. We found that genotypes of trembling aspen were more resistant to cavitation, exhibited more negative water potentials, and were more water-use-efficient than hybrid poplars. Under the boreal field test conditions, which included major regional droughts, height growth was negatively correlated with branch vessel diameter (Dv ) in both aspen and hybrid poplars and differences in Dv were highly conserved in aspen trees from different provenances. Differences between the hybrid poplars and aspen provenances suggest that these two groups employ different water-use strategies. The data also suggest that vessel diameter may be a key trait in evaluating growth performance in a boreal environment.

  11. Analysis of genetic and environmental effects on hybrid poplar rooting in Central and Northern Minnesota, USA

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Don Riemenschneider; Edmund Bauer

    2000-01-01

    We studied genetic and environmental effects on adventitious root initiation and growth because rooting is biologically prerequisite to the establishment of hybrid poplar plantations. Six clones from two pedigrees (pure Populus deltoides "cottonwoods" and P. deltoides x P. maximowiczii hybrids) were...

  12. Transgenic hybrid poplar for sustainable and scalable production of the commodity/specialty chemical, 2-phenylethanol.

    Directory of Open Access Journals (Sweden)

    Michael A Costa

    Full Text Available Fast growing hybrid poplar offers the means for sustainable production of specialty and commodity chemicals, in addition to rapid biomass production for lignocellulosic deconstruction. Herein we describe transformation of fast-growing transgenic hybrid poplar lines to produce 2-phenylethanol, this being an important fragrance, flavor, aroma, and commodity chemical. It is also readily converted into styrene or ethyl benzene, the latter being an important commodity aviation fuel component. Introducing this biochemical pathway into hybrid poplars marks the beginnings of developing a platform for a sustainable chemical delivery system to afford this and other valuable specialty/commodity chemicals at the scale and cost needed. These modified plant lines mainly sequester 2-phenylethanol via carbohydrate and other covalently linked derivatives, thereby providing an additional advantage of effective storage until needed. The future potential of this technology is discussed. MALDI metabolite tissue imaging also established localization of these metabolites in the leaf vasculature.

  13. Variation in the Growth Traits and Wood Properties of Hybrid White Poplar Clones

    Directory of Open Access Journals (Sweden)

    Huandi Ma

    2015-04-01

    Full Text Available The physical and chemical properties of poplar clones largely determine their suitability for different applications. The main objective of this study was to investigate clonal variation in four hybrid poplar clones grown at three sites in North China and identify the superior clone. Study materials were collected from four clones of hybrid white poplar: Populus tomentosa “LM50”, used as the control; two clones (Yiyang-1 and Yiyang-2, new hybrids of (P. tomentosa × P. bolleana × P. tomentosa “Truncata”; and Yiyang-3, a new hybrid of (P. tomentosa × P. bolleana × P. tomentosa “LM50”. In total, 192 individuals from four hybrid clones were randomly chosen for sampling. The growth traits of four 7-year-old clones were examined at three sites. We also measured the wood properties of four 6-year-old clones at the Fengfeng nursery. Variation in the growth traits and the ranking of stem volumes differed among sites. Fiber traits and wood chemical components showed significant interclonal variation. With regard to the comprehensive growth rate, cellulose content, holocellulose content, and fiber traits, Yiyang-1 exhibited the best performance among the four hybrid poplar clones, indicating its utility as a raw material for pulp and papermaking.

  14. PROPERTIES OF PARALLEL STRAND LUMBER FROM TWO HYBRID POPLAR CLONES USING MELAMINE UREA FORMALDEHYDE ADHESIVE

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    Ramazan Kurt,

    2012-06-01

    Full Text Available Experimental parallel strand lumbers (PSLs were manufactured from fast growing rotary peeled I-214 (Populus x euramericana and I-77/51 (Populus deltoides hybrid poplar clones veneer strands with melamine urea formaldehyde (MUF adhesive. The results showed that hybrid poplar clones can be used in PSLs manufacturing. Physical and mechanical properties of PSLs were affected by clone types. The I-77/51 clone had better properties and was found to be more suitable for PSLs manufacturing compared to the I-214 clone. PSLs properties were higher than those of solid woods (SWs and laminated veneer lumbers (LVLs of the same poplar clones. This increase may be due to materials, densification as a result of high pressure use, and the manufacturing techniques. The degree of contribution of SWs properties to the PSLs properties was lower than that of LVLs. This indicated that factors other than SWs properties played more important roles in the strength increase of PSLs.

  15. Efficient Agrobacterium-Mediated Transformation of Hybrid Poplar Populus davidiana Dode × Populus bollena Lauche

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    Xue Han

    2013-01-01

    Full Text Available Poplar is a model organism for high in vitro regeneration in woody plants. We have chosen a hybrid poplar Populus davidiana Dode × Populus bollena Lauche. By optimizing the Murashige and Skoog medium with (0.3 mg/L 6-benzylaminopurine and (0.08 mg/L naphthaleneacetic acid, we have achieved the highest frequency (90% for shoot regeneration from poplar leaves. It was also important to improve the transformation efficiency of poplar for genetic breeding and other applications. In this study, we found a significant improvement of the transformation frequency by controlling the leaf age. Transformation efficiency was enhanced by optimizing the Agrobacterium concentration (OD600 = 0.8–1.0 and an infection time (20–30 min. According to transmission electron microscopy observations, there were more Agrobacterium invasions in the 30-day-old leaf explants than in 60-day-old and 90-day-old explants. Using the green fluorescent protein (GFP marker, the expression of MD–GFP fusion proteins in the leaf, shoot, and root of hybrid poplar P. davidiana Dode × P. bollena Lauche was visualized for confirmation of transgene integration. Southern and Northern blot analysis also showed the integration of T-DNA into the genome and gene expression of transgenic plants. Our results suggest that younger leaves had higher transformation efficiency (~30% than older leaves (10%.

  16. Interpreting genotype‐by‐environment interaction for biomass production in hybrid poplars under short‐rotation coppice in Mediterranean environments

    National Research Council Canada - National Science Library

    Sixto, Hortensia; Gil, Paula M; Ciria, Pilar; Camps, Francesc; Cañellas, Isabel; Voltas, Jordi

    2016-01-01

    ...‐rotation coppice poplar plantations. Hybrid poplars are grown for biomass production under a wide range of climatic and edaphic conditions, but their adaptive performance in Mediterranean areas remains poorly characterized...

  17. Gaseous NO2 effects on stomatal behavior, photosynthesis and respiration of hybrid poplar leaves

    Science.gov (United States)

    In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (NO2, 4 microliter per liter) on stomatal conductance, photosynthesis, dark- and photorespiration of Populus alba x Populus berolinensis hybrid leaves using the photosynthesis system and scanning...

  18. Evaluating hybrid poplar rooting. I. genotype x environment interactions in three contrasting sites

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Don E. Riemenschneider; Richard B. Hall

    2002-01-01

    We need to learn more about environmental conditions that promote or hinder rooting of unrooted dormant hybrid poplar cuttings. Planting cuttings and recording survival after the growing season is not suitable to keep up with industrial demands for improved stock. This method does not provide information about specific genotype x environment interactions. We know very...

  19. Sapflow of hybrid poplar (Populus nigra L. x P. maximowiczii A. Henry 'NM6') during phytoremediation of landfill leachate

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Adam H. Wiese; Edmund O. Bauer; Don E. Riemenschneider

    2006-01-01

    Poplars are ideal for phytoremediation because of their high water usage, fast growth, and deep root systems. We measured in 2002 and 2003 the sapflow of hybrid poplars (Populus nigra L. x P. maximowiczii A. Henry 'NM6') planted in 1999 for phytoremediation of a landfill in Rhinelander, WI, USA (45.6?N, 89.4?W).

  20. The effect of mycorrhizal inoculation on hybrid poplar fine root dynamics in hydrocarbon contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, J.; Knight, J.D.; Van Rees, K.C.J. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Soil Science

    2006-07-01

    The biological remediation of contaminated soils using plants was discussed. Hybrid poplars are good candidates for phytoremediation because they root deeply, cycle large amounts of water and grow quickly. Their fine root system is pivotal in nutrient and water acquisition. Therefore, in order to maximize the phytoremediation potential, it is important to understand the response of the fine root system. In addition to degrading organic chemicals, ectomycorrhizal (ECM) fungi provide the host with greater access to nutrients. This study determined the relationship between residual soil hydrocarbons and soil properties at a field site. The effects of residual contamination on hybrid poplar fine root dynamics was also examined along with the effect of ectomycorrhizal colonization on hybrid poplar fine root dynamics when grown in diesel contaminated soil under controlled conditions. A minirhizotron camera inside a growth chamber captured images of mycorrhizal inoculation on hybrid poplar fine root production. Walker hybrid poplar seedlings were grown for 12 weeks in a control soil and also in a diesel contaminated soil. Seedlings were also grown in control and diesel contaminated, ectomycorrhizal inoculated soils. The inoculum was a mycorrhizal mix containing Pisolithus tinctorius and Rhizopogon spp. The images showed that colonization by ECM fungi increased hybrid poplar fine root production and aboveground biomass in a diesel contaminated soil compared to non-colonized trees in the same soil. Root:shoot ratios were much higher in the diesel contaminated/non-inoculated treatment than in either of the control soil treatments. Results of phytoremediation in diesel contaminated soil were better in the non-colonized treatment than in the colonized treatment. Both treatments removed more contaminants from the soil than the unplanted control. Much higher quantities of hydrocarbons were found sequestered in the roots from the inoculated treatment than from the non

  1. Comparing growth and fine root distribution in monocultures and mixed plantations of hybrid poplar and spruce

    Institute of Scientific and Technical Information of China (English)

    Lahcen Benomar; Annie DesRochers; Guy R.Larocque

    2013-01-01

    Disease prevention,biodiversity,productivity improvement and ecological considerations are all factors that contribute to increasing interest in mixed plantations.The objective of this study was to evaluate early growth and productivity of two hybrid poplar clones,P.balsamifera x trichocarpa (PBT) and P.maximowiczii x balsamifera (PMB),one improved family of Norway spruce (Picea glauca (PA)) and one improved family of white spruce (Picea abies (PG)) growing under different spacings in monocultures and mixed plots.The plantations were established in 2003 in Abitibi-Témiscamingue,Quebec,Canada,in a split plot design with spacing as the whole plot factor (1 × 1 m,3 × 3 m and 5 × 5 m) and mixture treatments as subplot factor (pure:PBT,PMB,PA and PG,and 1:1 mixture PBT:PA,PBT:PG,PMB:PA and PMB:PG).Results showed a beneficial effect of the hybrid poplar-spruce mixture on diameter growth for hybrid poplar clones,but not for the 5 × 5 m spacing because of the relatively young age of the plantations.Diameter growth of the spruces decreased in mixed plantings in the 1 × 1 m,while their height growth increased,resulting in similar aboveground biomass per tree across treatments.Because of the large size differences between spruces and poplars,aboveground biomass in the mixed plantings was generally less than that in pure poplar plots.Leaf nitrogen concentration for the two spruce families and hybrid poplar clone PMB was greater in mixed plots than in monocultures,while leaf nitrogen concentration of clone PBT was similar among mixture treatments.Because of its faster growth rate and greater soil resources demands,clone PMB was the only one showing an increase in leaf N with increased spacing between trees.Fine roots density was greater for both hybrid poplars than spruces.The vertical distribution of fine roots was insensitive to mixture treatment.

  2. Biomass and Volume Yield in Mature Hybrid Poplar Plantations on Temperate Abandoned Farmland

    Directory of Open Access Journals (Sweden)

    Benoit Truax

    2014-12-01

    Full Text Available In this study, we developed clone-specific allometric relationships, with the objective of calculating volume and biomass production after 13 years in 8 poplar plantations, located across an environmental gradient, and composed of 5 unrelated hybrid poplar clones. Allometry was found to be very similar for clones MxB-915311, NxM-3729 and DNxM-915508, all having P. maximoviczii parentage. Clones DxN-3570 and TxD-3230 also had a similar allometry; for a given DBH they have a lower stem volume, stem biomass and branch biomass than P. maximoviczii hybrids. Strong Site × Clone interactions were observed for volume and woody biomass growth, with DxN and TxD hybrids only productive on low elevation fertile sites, whereas P. maximovizcii hybrids were also very productive on higher elevation sites with moderate to high soil fertility. At the site level (5 clones mean, yield reached 27.5 and 22.7 m3/ha/yr. on the two best sites (high fertility and low elevation, confirming the great potential of southern Québec (Canada for poplar culture. The productivity gap between the most and least productive sites has widened from year 8 to year 13, highlighting the need for high quality abandoned farmland site selection in terms of climate and soil fertility. Although clone selection could optimize yield across the studied environmental gradient, it cannot fully compensate for inadequate site selection.

  3. Comparative Proteomic Analyses of the Hybrid Yellow-Poplar Stigma upon Pollination

    Institute of Scientific and Technical Information of China (English)

    Ming Li; Kun Wang; Pingfang Yang

    2012-01-01

    As basal angiosperm,Liriodendron chinense (Hemsl.) Sarg.and Liriodendron tulipifera Linn.are two species belong to Liriodendron genus.Hybrid yellowpoplar was obtained through crossing between Liriodendron tulipifera Linn.x L.chinense(Hemsl.) Sarg.Although hybrid yellow-poplar was strong in both growth and adaptation,its fruiting rate was as low as its parents.In this study,we profiled the proteome in hybrid yellow-poplar stigma before and after pollination.Comparative analyses of two dimensional gel electrophoresis maps from un-pollinated and pollinated stigmas showed that 30 proteins were increased and 27 proteins decreased after pollination.Functional categorization showed that most of them were metabolism-related,stress response related and protein biosynthesis,degradation and destinationrelated proteins.Also there were some redox-related and cell signaling-related proteins.All these changed proteins might involve in or affect the pollen and stigma interaction in hybrid yellow-poplar.This study will be helpful in understanding the regulation of Liriodendron genus sexual reproduction.

  4. Biochar as a substitute for vermiculite in potting mix for hybrid poplar

    Science.gov (United States)

    William L. Headlee; Catherine E. Brewer; Richard B. Hall

    2014-01-01

    The purpose of this study was to evaluate biochar as a substitute for vermiculite in potting mixes for unrooted vegetative cuttings of hybrid poplar as represented by the clone ‘NM6’ (Populus nigra L. × Populus suaveolens Fischer subsp. maximowiczii A. Henry). We compared three treatments (peat moss (control), peat moss mixed with vermiculite, and peat moss mixed with...

  5. Exploring the Role of Plant Genetics to Enhance Soil Carbon Sequestration in Hybrid Poplar Plantations

    Science.gov (United States)

    Wullschleger, S. D.; Garten, C. T.; Classen, A. T.

    2008-12-01

    Atmospheric CO2 concentrations have increased in recent decades and are projected to increase even further during the coming century. These projections have prompted scientists and policy-makers to consider how plants and soils can be used to stabilize CO2 concentrations. Although storing carbon in terrestrial ecosystems represents an attractive near-term option for mitigating rising atmospheric CO2 concentrations, enhancing the sequestration potential of managed systems will require advancements in understanding the fundamental mechanisms that control rates of carbon transfer and turnover in plants and soils. To address this challenge, a mathematical model was constructed to evaluate how changes in particular plant traits and management practices could affect soil carbon storage beneath hybrid poplar (Populus) plantations. The model was built from four sub-models that describe aboveground biomass, root biomass, soil carbon dynamics, and soil nitrogen transformations for trees growing throughout a user-defined rotation. Simulations could be run over one or multiple rotations. A sensitivity analysis of the model indicated changes in soil carbon storage were affected by variables that could be linked to hybrid poplar traits like rates of aboveground production, partitioning of carbon to coarse and fine roots, and rates of root decomposition. A higher ratio of belowground to aboveground production was especially important and correlated directly with increased soil carbon storage. Faster decomposition rates for coarse and fine dead roots resulted in a greater loss of carbon to the atmosphere as CO2 and less residual organic carbon for transfer to the fast soil carbon pool. Hence, changes in root chemistry that prolonged dead root decomposition rates, a trait that is under potential genetic control, were predicted to increase soil carbon storage via higher soil carbon inputs. Nitrogen limitation of both aboveground biomass production and soil carbon sequestration was

  6. Influence of Climate on the Growth of Hybrid Poplar in Michigan

    Directory of Open Access Journals (Sweden)

    Sophan Chhin

    2010-11-01

    Full Text Available This study examined the influence of climate on cumulative and interannual growth patterns of 18 full-sib families of hybrid poplars (Populus × smithii Boivin derived from different geographical locations (state counties of natural stands of aspen parents (trembling aspen (Populus tremuloides Michx. and bigtooth aspen (Populus grandidentata Michx.. The hybrids were subsequently planted in 1982 in southern mid-Michigan at Michigan State University (MSU Sandhill Research Area. Cumulative measures of hybrid poplar productivity (diameter, height, basal area, and stem volume in 2009 (28 years since plantation establishment were related via correlation analysis to geographical distances and climatic variables (temperature and precipitation between parental county locations and between parental locations and the plantation site. Tree-ring analysis methods (dendrochronology were also used to quantify the influence of climate (i.e., mean temperature and total precipitation at monthly and 3-month seasonal scales on interannual basal area growth rates of hybrid poplars. Analyses of cumulative measures of growth indicated a maternal effect: full-sib families had higher productivity if they had a maternal parent originating from a state county that was close to or had higher temperature (annual and summer and summer precipitation than corresponding parameters of the planting site. Principal component analysis indicated that 17 of the 18 full-sib families shared a large amount of common growth variation. Dendrochronological analyses of interannual growth-climate relationships indicated that growth was mainly affected by the degree of late summer to fall moisture stress in both the current and previous growth season, and the degree of winter harshness.

  7. Hybrid poplar plantations are suitable habitat for reintroduced forest herbs with conservation status.

    Science.gov (United States)

    Boothroyd-Roberts, Kathleen; Gagnon, Daniel; Truax, Benoit

    2013-01-01

    Plantations of fast-growing tree species may be of use in conservation by accelerating the restoration of forest habitat on abandoned farmland and increasing connectivity in fragmented landscapes. The objective of this study was to determine if hybrid poplar plantations can be suitable habitats for the reintroduction of native forest plant species and, if so, which abiotic factors predict successful reintroduction. Four species of forest herb species (Trillium grandiflorum, Sanguinaria canadensis, Maianthemum racemosum, Asarum canadense), of which three have legal conservation status, were transplanted into experimental plantations of two hybrid poplar clones and nearby second-growth woodlots at six sites in southern Quebec, Canada. The transplanted individuals were protected from deer browsing with exclusion cages. After two years, the plant responses of all four species were stable or increased over two years in both types of hybrid poplar plantations. Sanguinaria showed a better response in the plantations than in the woodlots, preferring the rich post-agricultural soils of the plantations with low C:N ratios. Asarum and Maianthemum showed no significant difference between stand types, while Trillium grew better in the woodlots than in the plantations. Much of the variability in the response of the latter three species was unexplained by the measured environmental variables. These results suggest that certain forest herb species can be reintroduced as juvenile plants into plantations, knowing that their spontaneous recolonization is often limited by dispersal and/or seedling establishment. Plantations could also contribute to the conservation of biodiversity by providing an environment for the cultivation of forest herb species as an alternative to their destructive harvest from natural populations.

  8. Land use and wind direction drive hybridization between cultivated poplar and native species in a Mediterranean floodplain environment.

    Science.gov (United States)

    Paffetti, Donatella; Travaglini, Davide; Labriola, Mariaceleste; Buonamici, Anna; Bottalico, Francesca; Materassi, Alessandro; Fasano, Gianni; Nocentini, Susanna; Vettori, Cristina

    2018-01-01

    Deforestation and intensive land use management with plantations of fast-growing tree species, like Populus spp., may endanger native trees not only by eliminating or reducing their habitats, but also by diminishing their species integrity via hybridization and introgression. The genus Populus has persistent natural hybrids because clonal and sexual reproduction is common. The objective of this study was to assess the effect of land use management of poplar plantations on the spatial genetic structure and species composition in poplar stands. Specifically, we studied the potential breeding between natural and cultivated poplar populations in the Mediterranean environment to gain insight into spontaneous hybridization events between exotic and native poplars; we also used a GIS-based model to evaluate the potential threats related to an intensive land use management. Two study areas, both near to poplar plantations (P.×euramericana), were designated in the native mixed stands of P. alba, P. nigra and P.×canescens within protected areas. We found that the spatial genetic structure differed between the two stands and their differences depended on their environmental features. We detected a hybridization event with P.×canescens that was made possible by the synchrony of flowering between the poplar plantation and P.×canescens and facilitated by the wind intensity and direction favoring the spread of pollen. Taken together, our results indicate that natural and artificial barriers are crucial to mitigate the threats, and so they should be explicitly considered in land use planning. For example, our results suggest the importance of conserving rows of trees and shrubs along rivers and in agricultural landscapes. In sum, it is necessary to understand, evaluate, and monitor the spread of exotic species and genetic material to ensure effective land use management and mitigation of their impact on native tree populations. Copyright © 2017 Elsevier B.V. All rights

  9. SUITABILITY OF THREE HYBRID POPLAR CLONES FOR LAMINATED VENEER LUMBER MANUFACTURING USING MELAMINE UREA FORMALDEHYDE ADHESIVE

    Directory of Open Access Journals (Sweden)

    Ramazan Kurt

    2010-07-01

    Full Text Available Experimental laminated veneer lumbers (LVLs from rotary peeled I-214 (Populus x Euramericana and two Populus deltoides I-77/51 and S.307-26 fast growing hybrid poplar clones were manufactured with a melamine urea formaldehyde (MUF adhesive successfully. Two Populus deltoides clones that are grown in Turkey were used for the first time in LVLs manufacturing. The results showed that clone types affected physical and mechanical properties of LVLs. Populus deltoides clones had better physical and mechanical properties compared to Populus x Euramericana clone due to their higher density and fiber length values. S.307-26 clone had the highest and I-214 had the lowest properties among three hybrid poplar clones. The physical and mechanical properties of LVLs were higher than those of solid woods. This increase may be due to compaction factor (densification, manufacturing techniques, and the use of adhesives. The degree of contribution of solid wood properties to the LVLs’ properties was explained by using a contribution factor. Two Populus deltoides clones were found to be more suitable for LVLs manufacturing compared to Populus x Euramericana clone.

  10. Effects of apical meristem loss on sylleptic branching and growth of hybrid poplar

    Energy Technology Data Exchange (ETDEWEB)

    Zeleznik, Joseph D. [North Dakota State University, Fargo, ND (United States). Plant Sciences Department

    2007-07-15

    The effects of apical meristem loss on the growth and development of hybrid poplar trees was investigated. This was done by clipping back either the apical meristem alone (dividing cells), or the apical meristem plus a small amount of additional stem tissue (expanding cells, <1 cm), at various times during the first growing season. Two clones (NM6-nonsylleptic habit, and DN34-slightly sylleptic habit) were tested at close spacing (0.6 m) in the nursery. Clipping generally increased the number of sylleptic branches formed. Clipping 69 days after planting resulted in the largest number of sylleptic branches while clipping 4 weeks later gave no increase in syllepsis. Clipping temporarily reduced height growth of both clones but total height at the end of the first growing season was not affected by any treatment. There were some slight differences in growth during the second growing season; despite these differences, total stem biomass and total tree biomass after 2 years were not affected by temporary loss of the apical meristem in the first growing season. Results suggest that death or removal of hybrid poplar apical meristems by tip borers or ungulates has no long-term effects on aboveground growth as measured by height or biomass. (author)

  11. Predicting yields of short-rotation hybrid poplar (Populus spp.) for the United States through model-data synthesis.

    Science.gov (United States)

    Wang, Dan; LeBauer, David; Dietze, Michael

    2013-06-01

    Hybrid poplar (Populus spp.) is an important biomass crop being evaluated for cellulosic ethanol production. Predictions of poplar growth, rotation period, and soil carbon sequestration under various growing conditions, soils, and climates are critical for farmers and managers planning to establish short-rotation forestry (SRF) plantations. In this study, we used an ecoinformatics workflow, the Predictive Ecosystem Analyzer (PEcAn), to integrate literature data and field measurements into the Ecosystem Demography 2 (ED2) model to estimate yield potential of poplar plantations. Within PEcAn 164 records of seven different traits from the literature were assimilated using a Bayesian meta-analysis. Next, variance decomposition identified seven variables for further constraint that contributed > 80% to the uncertainty in modeled yields: growth respiration, dark respiration, quantum efficiency, mortality coefficient, water conductance, fine-root allocation, and root turnover rate. Assimilation of observed yields further constrained uncertainty in model parameters (especially dark respiration and root turnover rate) and biomass estimates. Additional measurements of growth respiration, mortality, water conductance, and quantum efficiency would provide the most efficient path toward further constraint of modeled yields. Modeled validation demonstrated that ED2 successfully captured the interannual and spatial variability of poplar yield observed at nine independent sites. Site-level analyses were conducted to estimate the effect of land use change to SRF poplar on soil C sequestration compared to alternate land uses. These suggest that poplar plantations became a C sink within 18 years of conversion from corn production or existing forest. Finally, poplar yields were estimated for the contiguous United States at a half degree resolution in order to determine potential productivity, estimate the optimal rotation period, and compare poplar to perennial grass yields. This

  12. Soil Carbon Stocks in Two Hybrid Poplar-Hay Crop Systems in Southern Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Kiara Winans

    2014-08-01

    Full Text Available Tree-based intercropping (TBI systems, consisting of a medium to fast-growing woody species planted in widely-spaced rows with crops cultivated between tree rows, are a potential sink for atmospheric carbon dioxide (CO2. TBI systems contribute to farm income in the long-term by improving soil quality, as indicated by soil carbon (C storage, generating profits from crop plus tree production and potentially through C credit trading. The objectives of the current study were: (1 to evaluate soil C and nitrogen (N stocks in soil depth increments in the 0–30 cm layer between tree rows of nine-year old hybrid poplar-hay intercropping systems, to compare these to C and N stocks in adjacent agricultural systems; and (2 to determine how hay yield, litterfall and percent total light transmittance (PTLT were related to soil C and N stocks between tree rows and in adjacent agricultural systems. The two TBI study sites (St. Edouard and St. Paulin had a hay intercrop with alternating rows of hybrid poplar clones and hardwoods and included an adjacent agricultural system with no trees (i.e., the control plots. Soil C and N stocks were greater in the 0–5 cm depth increment of the TBI system within 1 m of the hardwood row, to the west of the poplar row, compared to the sampling point 1 m east of poplar at St. Edouard (p = 0.02. However, the agricultural system stored more soil C than the nine-year old TBI system in the 20–30 cm and 0–30 cm depth increments. Accumulation of soil C in the 20–30 cm depth increment could be due to tillage-induced burial of non-harvested crop residues at the bottom of the plow-pan. Soil C and N stocks were similar at all depth increments in TBI and agricultural systems at St. Paulin. Soil C and N stocks were not related to hay yield, litterfall and PTLT at St. Paulin, but hay yield and PTLT were significantly correlated (R = 0.87, p < 0.05, n = 21, with lower hay yield in proximity to trees in the TBI system and similar hay

  13. Clone-Specific Response in Leaf Nitrate Reductase Activity among Unrelated Hybrid Poplars in relation to Soil Nitrate Availability

    Directory of Open Access Journals (Sweden)

    Julien Fortier

    2012-01-01

    Full Text Available In this field study, we used in vivo NRA activity in hybrid poplar leaves as an indicator of NO3- assimilation for five unrelated hybrid poplar clones. We also examined if leaf NRA of these clones is influenced to the same extent by different levels of soil NO3- availability in two riparian agroforestry systems located in pastures. Leaf NRA differences of more than one order of magnitude were observed between the clones, clearly showing their different abilities to reduce NO3- in leaves. Clone DxN-3570, a P. deltoides x P. nigra hybrid (Aigeiros intrasectional hybrid, always had the highest leaf NRA during the field assays. This clone was also the only one to increase its leaf NRA with increasing NO3- soil availability, which resulted in a significant Site x Clone interaction and a positive relationship between soil NO3- concentration and NRA. All of the four other clones studied had one or both parental species from the Tacamahaca section. They had relatively low leaf NRA and they did not increase their leaf NRA when grown on the NO3- rich site. These results provide evidence that NO3- assimilation in leaves varies widely among hybrid poplars of different parentages, suggesting potential preferences for N forms.

  14. Hybrid poplar and forest soil response to municipal and industrial by-products: a greenhouse study.

    Science.gov (United States)

    Cavaleri, Molly A; Gilmore, Daniel W; Mozaffari, Morteza; Rosen, Carl J; Halbach, Thomas R

    2004-01-01

    Little research has been conducted in the Lake States (Minnesota, Wisconsin, and Michigan) to evaluate the effects of municipal and industrial by-product applications on the early growth of short rotation woody crops such as hybrid poplar. Anticipated shortages of harvestable-age aspen in the next decade can be alleviated and rural development can be enhanced through the application of by-products to forest soils. This study was conducted to evaluate the effects of inorganic fertilizer, boiler ash, biosolids, and the co-application of ash and biosolids application on tree growth and soil properties by measuring hybrid poplar clone NM-6 (Populus nigra L. x P. maximowiczii A. Henry) yield, nutrient uptake, and select post-harvest soil properties after 15 wk of greenhouse growth. Treatments included a control of no amendment; agricultural lime; inorganic N, P, and K; three types of boiler ash; biosolids application rates equivalent to 70, 140, 210, and 280 kg available N ha(-1); and boiler ash co-applied with biosolids. All of the by-products treatments showed biomass production that was equal to or greater than inorganic fertilizer and lime treatments. A trend of increased biomass with increasing rates of biosolids was observed. Soil P concentration increased with increasing rates of biosolids application. None of the by-products treatments resulted in plant tissue metal concentrations greater than metal concentrations of plant tissue amended with inorganic amendments. Biosolids, boiler ash, and the co-application of biosolids and boiler ash together on forest soils were as beneficial to plant growth as inorganic fertilizers.

  15. Uptake and Translocation of Lesser-Chlorinated Polychlorinated Biphenyls (PCBs) in Whole Hybrid Poplar Plants after Hydroponic Exposure

    Science.gov (United States)

    Liu, Jiyan; Schnoor, Jerald L.

    2009-01-01

    Mono-, di-, tri-, and tetra-chlorinated polychlorinated biphenyls (PCBs) are congeners with greater volatility which remain in air, soils and sediments requiring treatment. In this study, the fate of these PCBs was investigated within whole poplar plants (Populus deltoides x nigra, DN34) with application for a treatment system such as a confined disposal facility for dredged material. Whole hybrid poplars were exposed hydroponically to a mixture of five congeners, common in the environment, having one to four chlorine atoms per molecule. Results indicated that PCB 3, 15, 28, 52, and 77 were initially sorbed to the root systems. The Root Concentration Factor (RCF) of PCBs during the exposure was calculated and correlated with Kow. PCB congeners were taken up by the roots of hybrid poplar, and the translocation of PCBs to stems was inversely related to congener hydrophobicity (Log Kow). PCB 3 and 15 were translocated to the upper stem at small but significant rates. PCB 28 was translocated to the wood of the main stem but no farther; translocation from the roots was not detected for PCB 52 and 77. The distribution of PCBs within poplars was determined, and mass balances were completed to within 15% for each chemical except for PCB 3, the most volatile congener. This is the first report on the transport of PCBs through whole plants designed for use in treatment at disposal facilities. PMID:18793792

  16. Potential for Hybrid Poplar Riparian Buffers to Provide Ecosystem Services in Three Watersheds with Contrasting Agricultural Land Use

    Directory of Open Access Journals (Sweden)

    Julien Fortier

    2016-02-01

    Full Text Available In temperate agricultural watersheds, the rehabilitation of tree vegetation in degraded riparian zones can provide many ecosystem services. This study evaluated ecosystem service provision potential following the conversion of non-managed herbaceous buffers to hybrid poplar (Populus spp. buffers in three watersheds (555–771 km2 of southern Québec (Canada, with contrasting agricultural land uses. To extrapolate services at the watershed level, total stream length where hybrid poplars could be established was calculated using GIS data from hydrological and land cover maps. After nine years, a 100% replacement of herbaceous buffers by hybrid poplar buffers along farm streams could lead to the production of 5280–76,151 tons of whole tree (stems + branches biomass, which could heat 0.5–6.5 ha of greenhouses for nine years, with the potential of displacing 2–29 million litres of fuel oil. Alternatively, the production of 3887–56,135 tons of stem biomass (fuelwood could heat 55–794 new farmhouses or 40–577 old farmhouses for nine years. Producing fuelwood in buffers rather than in farm woodlots could create forest conservation opportunities on 300–4553 ha. Replacing all herbaceous buffers by poplar buffers could provide potential storage of 2984–42,132 t C, 29–442 t N and 3–56 t P in plant biomass, if woody biomass is not harvested. The greatest potential for services provision was in the Pike River watershed where agriculture is the dominant land use. A review of the potential services of poplar buffers is made, and guidelines for managing services and disservices are provided.

  17. Investigating the drought-stress response of hybrid poplar genotypes by metabolite profiling.

    Science.gov (United States)

    Barchet, Genoa L H; Dauwe, Rebecca; Guy, Robert D; Schroeder, William R; Soolanayakanahally, Raju Y; Campbell, Malcolm M; Mansfield, Shawn D

    2014-11-01

    Drought stress is perhaps the most commonly encountered abiotic stress plants experience in the natural environment, and it is one of the most important factors limiting plant productivity. Here, we employed untargeted metabolite profiling to examine four drought-stressed hybrid poplar (Populus spp.) genotypes for their metabolite content, using gas chromatography coupled to mass spectrometry. The primary objective of these analyses was to characterize the metabolite profile of poplar trees to assess relative drought resistance and to investigate the underlying biochemical mechanisms employed by the genotypes to combat drought. Metabolite profiling identified key metabolites that increased or decreased in relative abundance upon exposure to drought stress. Overall, amino acids, the antioxidant phenolic compounds catechin and kaempferol, as well as the osmolytes raffinose and galactinol exhibited increased abundance under drought stress, whereas metabolites involved in photorespiration, redox regulation and carbon fixation showed decreased abundance under drought stress. One clone in particular, Okanese, displayed unique responses to the imposed drought conditions. This clone was found to have higher leaf water potential, but lower growth rate relative to the other clones tested. Okanese also had lower accumulation of osmolytes such as raffinose, galactinol and proline, but higher overall levels of antioxidants such as catechin and dehydroascorbic acid. As such, it was proposed that osmotic adjustment as a mechanism for drought avoidance in this clone is not as well developed in comparison with the other clones investigated in this study, and that a possible alternative mechanism for the enhanced drought avoidance displayed by Okanese may be due to differential allocation of resources or better retention of water.

  18. Efficient Agrobacterium-mediated transformation of commercial hybrid poplar Populus nigra L. x P. maximowiczii A. Henry.

    Science.gov (United States)

    Yevtushenko, Dmytro P; Misra, Santosh

    2010-03-01

    Many economically important species of Populus, especially those in sections Aigeiros and Tacamahaca, remain recalcitrant to genetic transformation. In this study, a simple and reliable protocol was developed for the efficient Agrobacterium-mediated transformation of a difficult-to-transform, but commercially viable, hybrid poplar Populus nigra L. x P. maximowiczii A. Henry (NM6). A plant transformation vector designed to express the beta-glucuronidase (GUS) gene was used to detect transformation events at early stages of plant regeneration and to optimize parameters affecting poplar transformation. The use of zeatin riboside in shoot-induction medium, regeneration of shoots via indirect organogenesis, and early selection pressure were the major modifications that drastically improved the efficiency of poplar transformation and minimized the number of untransformed regenerants. Transgenic shoots were routinely obtained 4-10 weeks after co-culture with A. tumefaciens, with a greater than 90% rate of plant recovery. Stable transgene integration, ranging from a single insertion to ten copies per genome, was confirmed by Southern blot analysis. The mean transformation frequency was 36.3% and about two-thirds of the lines had 1-2 transgene copies. Among the explants, petioles and leaves had a higher transformation frequency than did stem segments. Growth characteristics and the morphology of transgenic poplar plants were identical to untransformed controls. These findings will accelerate the development of P. nigra x P. maximowiczii plants with novel traits, and may also be useful to improve transformation procedures for other Populus species.

  19. Early differentiation in biomass production and carbon sequestration of white poplar and its two hybrids in Central Iran

    Institute of Scientific and Technical Information of China (English)

    Hormoz Sohrabi; Mohammad Kazem Parsapour; Ali Soltani; Yaghoub Iranmanesh

    2015-01-01

    We assessed the potential of white poplar (Populus alba L.) and its inter-sectional hybridization with euphrates poplar (P. euphratica Oliv.) for carbon storage and sequestration in central Iran. Trials were established at planting density of 2,500 trees per hectare in block ran-domized design with three replicates. After 6 years, we measured the above-ground biomass of tree components (trunk, branch, bark, twig and leaf), and assessed soil carbon at three depths. P. alba × euphratica plantation stored significantly more carbon (22.3 t ha-1) than P. alba (16.7 t ha-1) and P. euphratica × alba (13.1 t ha-1). Most of the carbon was accumulated in the above-ground biomass (61.1%in P. alba, 72.4%in P. alba × euphra-tica and 56.0% in P. euphratica × alba). There was no significant difference in soil carbon storage. Also, biomass allocation was different between white poplar P. alba and its inter-sectional hybridization. Therefore, there was a yield difference due to genomic imprinting, which increased the possibility that paternally and maternally inherited wood production alleles would be differentially expressed in the new crossing.

  20. Allometric Biomass, Biomass Expansion Factor and Wood Density Models for the OP42 Hybrid Poplar in Southern Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Anders Tærø; Nord-Larsen, Thomas; Stupak, Inge

    2015-01-01

    Biomass and biomass expansion factor functions are important in wood resource assessment, especially with regards to bioenergy feedstocks and carbon pools. We sampled 48 poplar trees in seven stands with the purpose of estimating allometric models for predicting biomass of individual tree...... components, stem-to-aboveground biomass expansion factors (BEF) and stem basic densities of the OP42 hybrid poplar clone in southern Scandinavia. Stand age ranged from 3 to 31 years, individual tree diameter at breast height (dbh) from 1.2 to 41 cm and aboveground tree biomass from 0.39 to 670 kg. Models...... for predicting total aboveground leafless, stem and branch biomass included dbh and tree height as predictor variables and explained more than 97 % of the total variation. The BEF was approaching 2.0 for the smallest trees but declined with increasing tree size and stabilized around 1.2 for trees with dbh >10 cm...

  1. Post-treatment mechanical refining as a method to improve overall sugar recovery of steam pretreated hybrid poplar.

    Science.gov (United States)

    Dou, Chang; Ewanick, Shannon; Bura, Renata; Gustafson, Rick

    2016-05-01

    This study investigates the effect of mechanical refining to improve the sugar yield from biomass processed under a wide range of steam pretreatment conditions. Hybrid poplar chips were steam pretreated using six different conditions with or without SO2. The resulting water insoluble fractions were subjected to mechanical refining. After refining, poplar pretreated at 205°C for 10min without SO2 obtained a 32% improvement in enzymatic hydrolysis and achieved similar overall monomeric sugar recovery (539kg/tonne) to samples pretreated with SO2. Refining did not improve hydrolyzability of samples pretreated at more severe conditions, nor did it improve the overall sugar recovery. By maximizing overall sugar recovery, refining could partially decouple the pretreatment from other unit operations, and enable the use of low temperature, non-sulfur pretreatment conditions. The study demonstrates the possibility of using post-treatment refining to accommodate potential pretreatment process upsets without sacrificing sugar yields.

  2. Enhancement of Lignin Biopolymer Isolation from Hybrid Poplar by Organosolv Pretreatments

    Directory of Open Access Journals (Sweden)

    Miao Wu

    2014-01-01

    Full Text Available Lignocellulosic biomass is an abundant renewable resource that has the potential to displace petroleum in the production of biomaterials and biofuels. In the present study, the fractionation of different lignin biopolymers from hybrid poplar based on organosolv pretreatments using 80% aqueous methanol, ethanol, 1-propanol, and 1-butanol at 220°C for 30 min was investigated. The isolated lignin fractions were characterized by Fourier transform infrared spectroscopy (FT-IR, high-performance anion exchange chromatography (HPAEC, 2D nuclear magnetic resonance (2D NMR, and thermogravimetric analysis (TGA. The results showed that the lignin fraction obtained with aqueous ethanol (EOL possessed the highest yield and the strongest thermal stability compared with other lignin fractions. In addition, other lignin fractions were almost absent of neutral sugars (1.16–1.46% though lignin preparation extracted with 1-butanol (BOL was incongruent (7.53%. 2D HSQC spectra analysis revealed that the four lignin fractions mainly consisted of β-O-4′ linkages combined with small amounts of β-β′ and β-5′ linkages. Furthermore, substitution of Cα in β-O-4′ substructures had occurred due to the effects of dissolvent during the autocatalyzed alcohol organosolv pretreatments. Therefore, aqueous ethanol was found to be the most promising alcoholic organic solvent compared with other alcohols to be used in noncatalyzed processes for the pretreatment of lignocellulosic biomass in biorefinery.

  3. In vitro shoot regeneration from leaf mesophyll protoplasts of hybrid poplar (Populus nigra x P. maximowiczii).

    Science.gov (United States)

    Park, Y G; Son, S H

    1992-02-01

    Protoplasts were isolated from leaf mesophyll of hybrid poplar (Populus nigra X P. maximowiczii) with a mean yield of 10.4 x 10(6) protoplasts per g fresh weight using 2.0% Cellulase 'Onozuka' R-10, 0.8% Macerozyme R-10, 1.2% Hemicellulase, 2.0% Driselase, and 0.05% Pectolyase Y-23 with CPW salts solution containing 0.6 M mannitol, 0.002 M DTT, 3 mM MES at pH 5.6. A liquid plating method produced the highest frequency of dividing protoplasts (48.6%) using an MS medium without NH4NO3. The highest percent of colony formation was 22.8%, produced with fabric supported semi-solid (0.5% w/v) agar plating method using the same culture medium. Growing cell colonies and/or micro-calli were transferred to a fresh semisolid agar medium containing 0.44 μM BAP and 9.0 μM 2,4-D. Multiple shoots were produced from protoplast-derived callus after culture on MS medium containing 6.8 μM zeatin. After root induction on half-strength MS medium that lacked growth regulators, shoots were transferred to pots containing artificial soil mix.

  4. Tree-based intercropping systems increase growth and nutrient status of hybrid poplar: a case study from two Northeastern American experiments.

    Science.gov (United States)

    Rivest, David; Cogliastro, Alain; Olivier, Alain

    2009-01-01

    Tree-based intercropping is considered to be a potentially useful land use system for mitigating negative environmental impacts from intensive agriculture such as nutrient leaching and greenhouse gas emissions. Rapid early growth of trees is critical for rapidly accruing environmental benefits provided by the trees. We tested the hypothesis that intercropping increases the growth and nutrient status of young hybrid poplars (Populus spp.), compared to a harrowing alley treatment (i.e., no intercrop), in two experimental sites (St-Rémi and St-Edouard) in southern Québec, Canada. Three hybrid poplar clones (TD3230, Populus trichocarpa x deltoides; DN3308, P. deltoides x nigra; and NM3729, P. nigra x maximowiczii) were planted at St-Rémi. Clones DN3333 and DN3570 were planted at St-Edouard. At St-Rémi, intercropping comprised a 4-year succession of three crops of soybean (Glycine max (L.) Merr.) and barley (Hordeum vulgare L.). At St-Edouard, intercropping comprised a 3-year succession of buckwheat (Fagopyrum esculentum Moench), winter rye (Secale cereale L.), and winter wheat (Triticum aestivum L.). At St-Rémi, four years after treatment began, leafless aboveground biomass of hybrid poplars in the intercropping treatment was 37% higher compared to that in the harrowing treatment. At St-Edouard, after the third growing season, leafless aboveground biomass of hybrid poplars in the intercropping treatment was significantly higher by 40%. Vector analysis of foliar nutrient concentrations and comparison with critical concentration values showed that N (both sites) and K (St-Edouard) were the most limiting nutrients. Hybrid poplar clones responded similarly to treatments, with no consistent differences in tree growth observed between clones. We conclude that tree-based intercropping systems may offer an effective means of improving the early growth of hybrid poplars planted to provide both environmental services and high-value timber.

  5. Histological characterization of gell formation and lesion development on leaves of Phaseolus vulgaris and clones of hybrid poplar after exposure to simulated sulfate acid rain

    Energy Technology Data Exchange (ETDEWEB)

    Dacosta, F.

    1978-01-01

    Histological investigations with leaves of several hybrid poplar clones illustrate gall formations in response to simulated acid rain that result from hyperplasia and hypertrophy of mesophyll cells. Similar experiments with phaseolus vulgaris and clones of hybrid poplar show a sequence of events that follow a general pattern of adaxial epidermis destruction, injury to palisade parenchyma and eventual destruction of more interior tissues after continued exposure to one, six-minute, rain event daily. Results show that most (95%) lesions on Phaseolus vulgaris developed near trichomes and stomata after exposure to the simulated acid rain.

  6. Influence of brick air scrubber by-product on growth and development of corn and hybrid poplar.

    Science.gov (United States)

    Thomas, Carla N; Bauerle, William L; Owino, Tom O; Chastain, John P; Klaine, Stephen J

    2007-03-01

    Studies were conducted to determine the effects of spent reagent from air pollution control scrubbers used at a brick manufacturing facility on emergence, growth, and physiological responses of corn and hybrid poplar plants. Scrubber by-product was obtained from General Shale Brick, Louisville, KY. Potting substrate was weighed and quantities of scrubber by-product were added to the substrate to obtain treatments of 0%, 6.25%, 12.5%, 25%, 50%, 75%, and 100% scrubber by-product (w:w) for the corn study. Each treatment mix was potted into nine replicate polyethylene pots and four corn seeds were sown per pot. The pots were randomized in a greenhouse at Clemson University and the number of seedlings emerging from each treatment, dark-adapted leaf chlorophyll a fluorescence, and shoot heights were measured at the end of a 21-day growth period. Then, dry shoot biomass was determined for plants from each treatment and plant tissues were analyzed for selected constituents. For the poplar study, nine-inch cuttings of hybrid poplar clone 15-29 (Populus trichocarpa x P. deltoides) and clone OP367 (P. deltoides x P. nigra) were planted in treatments of scrubber by-product-potting soil mixes of 0% , 5% , 10% , and 25% w:w. Leaf chlorophyll a fluorescence was measured over six weeks and cumulative leaf area, dry biomass, and nutrient content of tissues were determined upon harvest. Results of these studies indicate that percent seedling emergence for corn plants decreased with increasing scrubber by-product application rates. Application rates up to 12.5% scrubber by-product w:w had no adverse effect on corn seedling emergence. Shoot elongation, biomass production, and the status of the photosynthetic apparatus of the seedlings were also not severely impaired at applications below this level. A critical value of 58.2% w:w scrubber by-product was estimated to cause 25% inhibition of seedling emergence. Biomass production, cumulative leaf area, and chlorophyll a fluorescence of

  7. Spatial variability of soil carbon and nitrogen in two hybrid poplar-hay crop systems in southern Quebec, Canada

    Science.gov (United States)

    Winans, K. S.

    2013-12-01

    Canadian agricultural operations contribute approximately 8% of national GHG emissions each year, mainly from fertilizers, enteric fermentation, and manure management (Environment Canada, 2010). With improved management of cropland and forests, it is possible to mitigate GHG emissions through carbon (C) sequestration while enhancing soil and crop productivity. Tree-based intercropped (TBI) systems, consisting of a fast-growing woody species such as poplar (Populus spp.) planted in widely-spaced rows with crops cultivated between tree rows, were one of the technologies prioritized for investigation by the Agreement for the Agricultural Greenhouse Gases Program (AAGGP), because fast growing trees can be a sink for atmospheric carbon-dioxide (CO2) as well as a long-term source of farm income (Montagnini and Nair, 2004). However, there are relatively few estimates of the C sequestration in the trees or due to tree inputs (e.g., fine root turnover, litterfall that gets incorporated into SOC), and hybrid poplars grow exponentially in the first 8-10 years after planting. With the current study, our objectives were (1) to evaluate spatial variation in soil C and nitrogen (N) storage, CO2 and nitrogen oxide (N20), and tree and crop productivity for two hybrid poplar-hay intercrop systems at year 9, comparing TBI vs. non-TBI systems, and (2) to evaluate TBI systems in the current context of C trading markets, which value C sequestration in trees, unharvested crop components, and soils of TBI systems. The study results will provide meaningful measures that indicate changes due to TBI systems in the short-term and in the long-term, in terms of GHG mitigation, enhanced soil and crop productivity, as well as the expected economic returns in TBI systems.

  8. Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis

    Directory of Open Access Journals (Sweden)

    Beaulieu Carole

    2010-12-01

    Full Text Available Abstract Background Thaxtomin A (TA, a phytotoxin produced by the phytopathogen Streptomyces scabies, is essential for the development of potato common scab disease. TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides cell suspensions can activate a cellular program leading to cell death. In contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. The purpose of this study is to characterize TA-habituated cells and the mechanisms that may be involved in enhancing resistance to TA. Results Habituation to TA was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than three years. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition, with a reduction in cellulose and an increase in pectin levels. Remarkably, high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover, these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis, dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using an Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications. Conclusions We have shown that habituation to TA induced durable resistance to the bacterial toxin in poplar cells. TA-habituation also enhanced resistance to two other structurally

  9. Specific gravity of hybrid poplars in the north-central region, USA: within-tree variability and site × genotype effects

    Science.gov (United States)

    William L. Headlee; Ronald S. Jr. Zalesny; Richard B. Hall; Edmund O. Bauer; Bradford Bender; Bruce A. Birr; Raymond O. Miller; Jesse A. Randall; Adam H. Wiese

    2013-01-01

    Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most...

  10. Evaluation of two hybrid poplar clones as constructed wetland plant species for treating saline water high in boron and selenium, or waters only high in boron

    Science.gov (United States)

    Wetland mesocosms were constructed to assess two salt- and B-tolerant hybrid poplar clones (Populus trichocarpa ×P. deltoides×P. nigra '345-1' and '347-14') for treating saline water high in boron (B) and selenium (Se). In addition, a hydroponic experiment was performed to test the B tolerance and B...

  11. Reduced expression of the SHORT-ROOT gene increases the rates of growth and development in hybrid poplar and Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jiehua Wang

    Full Text Available SHORT-ROOT (SHR is a well characterized regulator of cell division and cell fate determination in the Arabidopsis primary root. However, much less is known about the functions of SHR in the aerial parts of the plant. In this work, we cloned SHR gene from Populus trichocarpa (PtSHR1 as an AtSHR ortholog and down-regulated its expression in hybrid poplar (Populus tremula×P. tremuloides Michx-clone T89 in order to determine its physiological functions in shoot development. Sharing a 90% similarity to AtSHR at amino acid level, PtSHR1 was able to complement the Arabidopsis shr mutant. Down regulation of PtSHR1 led to a strong enhancement of primary (height and secondary (girth growth rates in the transgenic poplars. A similar approach in Arabidopsis showed a comparable accelerated growth and development phenotype. Our results suggest that the response to SHR could be dose-dependent and that a partial down-regulation of SHR could lead to enhanced meristem activity and a coordinated acceleration of plant growth in woody species. Therefore, SHR functions in plant growth and development as a regulator of cell division and meristem activity not only in the roots but also in the shoots. Reducing SHR expression in transgenic poplar was shown to lead to significant increases in primary and secondary growth rates. Given the current interest in bioenergy crops, SHR has a broader role as a key regulator of whole plant growth and development and SHR suppression has considerable potential for accelerating biomass accumulation in a variety of species.

  12. Cellulose and lignin biosynthesis is altered by ozone in wood of hybrid poplar (Populus tremula × alba).

    Science.gov (United States)

    Richet, Nicolas; Afif, Dany; Huber, Françoise; Pollet, Brigitte; Banvoy, Jacques; El Zein, Rana; Lapierre, Catherine; Dizengremel, Pierre; Perré, Patrick; Cabané, Mireille

    2011-06-01

    Wood formation in trees is a dynamic process that is strongly affected by environmental factors. However, the impact of ozone on wood is poorly documented. The objective of this study was to assess the effects of ozone on wood formation by focusing on the two major wood components, cellulose and lignin, and analysing any anatomical modifications. Young hybrid poplars (Populus tremula × alba) were cultivated under different ozone concentrations (50, 100, 200, and 300 l l(-1)). As upright poplars usually develop tension wood in a non-set pattern, the trees were bent in order to induce tension wood formation on the upper side of the stem and normal or opposite wood on the lower side. Biosynthesis of cellulose and lignin (enzymes and RNA levels), together with cambial growth, decreased in response to ozone exposure. The cellulose to lignin ratio was reduced, suggesting that cellulose biosynthesis was more affected than that of lignin. Tension wood was generally more altered than opposite wood, especially at the anatomical level. Tension wood may be more susceptible to reduced carbon allocation to the stems under ozone exposure. These results suggested a coordinated regulation of cellulose and lignin deposition to sustain mechanical strength under ozone. The modifications of the cellulose to lignin ratio and wood anatomy could allow the tree to maintain radial growth while minimizing carbon cost.

  13. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress

    Directory of Open Access Journals (Sweden)

    Anne eHennig

    2015-05-01

    Full Text Available Woody crops such as poplars (Populus can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested nine-month-old plants of four tetraploid Populus tremula (L. x P. tremuloides (Michx. lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites.

  14. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress.

    Science.gov (United States)

    Hennig, Anne; Kleinschmit, Jörg R G; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites.

  15. Organosolv ethanol lignin from hybrid poplar as a radical scavenger: relationship between lignin structure, extraction conditions, and antioxidant activity.

    Science.gov (United States)

    Pan, Xuejun; Kadla, John F; Ehara, Katsunobu; Gilkes, Neil; Saddler, Jack N

    2006-08-09

    Twenty-one organosolv ethanol lignin samples were prepared from hybrid poplar (Populus nigra xP. maximowiczii) under varied conditions with an experimental matrix designed using response surface methodology (RSM). The lignin preparations were evaluated as potential antioxidants. Results indicated that the lignins with more phenolic hydroxyl groups, less aliphatic hydroxyl groups, low molecular weight, and narrow polydispersity showed high antioxidant activity. Processing conditions affected the functional groups and molecular weight of the extracted organosolv ethanol lignins, and consequently influenced the antioxidant activity of the lignins. In general, the lignins prepared at elevated temperature, longer reaction time, increased catalyst, and diluted ethanol showed high antioxidant activity. Regression models were developed to enable the quantitative prediction of lignin characteristics and antioxidant activity based on the processing conditions.

  16. Tree and stand water fluxes of hybrid poplar clone (Populus nigra x P. maximowiczii) in short rotation coppice culture

    Science.gov (United States)

    Fischer, M.; Trnka, M.; Kucera, J.; Zalud, Z.

    2010-09-01

    This study reports on evapotranspiration and tree water use in short rotation coppice culture of hybrid poplar (Populus nigra x P. maximowiczii) for biomass energy in the Czech Republic. The high density poplar plantation (10 000 trees per ha) was established in 2003 on arable land in Czech-Moravian Highland (49°32´ N, 16°15´ E, 530 m a.s.l.) and has been coppiced in rotation period of 7 years. Firstly, evapotranspiration of the stand has been estimated by applying the Bowen ratio-energy budget method, which is considered as reliable, robust, quite simple and inexpensive technique with comparable results to eddy covariance and lysimeters. The gaps in evapotranspiration diurnal patterns caused by limitation of the bowen ratio method were filled with simple linear regression model based on relation between potential and actual evapotranspiration with regard to soil water availability and leaf area index and thus the daily, monthly and seasonal totals could be calculated. The amount of evapotranspiration during the growing season 2009 (1 March - 31 October) was 593 mm with highest monthly total 116 mm in June. Mean daily water loss over the season reached 2.43 mm per day. During the hot summer day, the maximal value 5.73 mm per day, which presented 89 % of potential evapotranspiration calculated by Penman equation, was recorded with a peak rate 0.94 mm per hour. Secondly, the transpiration was measured by sap flow tissue heat balance techniques on four individual trees with greatest stem diameters (11 - 12 cm d.b.h.) and height of 12 - 12.5 m. Relatively high transpiration values by the poplars were found during the measured part of growing season (18 June - 31 October), with maximum and mean daily transpiration of 44.41 dm3 and 16.69 dm3 per day, respectively. The seasonal transpiration of the most vigorous from the investigated individuals amounted 2542 dm3. Because in this study we didńt evaluate the transpiration of thinner trees (technical features of sap

  17. Phasing Variants in Poplar Trees using a Hybrid of Short & Long Read Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Schackwitz, Wendy; Martin, Joel; Lipzen, Anna; Pennacchio, Len; Tuskan, Gerald

    2013-03-26

    Poplar grow throughout the West coast & are adapted to extremely variable conditions. To examine what allows for this wide range of growth conditions, Jerry Tuskan's team has collected 1000 different individuals from British Columbia to California. In 2009, three Common Gardens were established where each individual was cloned in triplicate. Nearly all of these trees have been sequenced using short read technology, revealing a huge degree of variation in genotype. Correlating this genomic variation to phenotype would be greatly be strengthened if the variants could be phased into long haplotype blocks.

  18. Chemical responses to modified lignin composition in tension wood of hybrid poplar (Populus tremula x Populus alba).

    Science.gov (United States)

    Al-Haddad, Jameel M; Kang, Kyu-Young; Mansfield, Shawn D; Telewski, Frank W

    2013-04-01

    The effect of altering the expression level of the F5H gene was investigated in three wood tissues (normal, opposite and tension wood) in 1-year-old hybrid poplar clone 717 (Populus tremula × Populus alba L.), containing the F5H gene under the control of the C4H promoter. Elevated expression of the F5H gene in poplar has been previously reported to increase the percent syringyl content of lignin. The wild-type and three transgenic lines were inclined 45° for 3 months to induce tension wood formation. Tension and opposite wood from inclined trees, along with normal wood from control trees, were analyzed separately for carbohydrates, lignin, cellulose crystallinity and microfibril angle (MFA). In the wild-type poplar, the lignin in tension wood contained a significantly higher percentage of syringyl than normal wood or opposite wood. However, there was no significant difference in the percent syringyl content of the three wood types within each of the transgenic lines. Increasing the F5H gene expression caused an increase in the percent syringyl content and a slight decrease in the total lignin in normal wood. In tension wood, the addition of a gelatinous layer in the fiber walls resulted in a consistently lower percentage of total lignin in the tissue. Acid-soluble lignin was observed to increase by up to 2.3-fold in the transgenic lines. Compared with normal wood and opposite wood, cell wall crystallinity in tension wood was higher and the MFA was smaller, as expected, with no evidence of an effect from modifying the syringyl monomer ratio. Tension wood in all the lines contained consistently higher total sugar and glucose percentages when compared with normal wood within the respective lines. However, both sugar and glucose percentages were lower in the tension wood of transgenic lines when compared with the tension wood of wild-type trees. Evaluating the response of trees with altered syringyl content to gravity will improve our understanding of the changes

  19. Green revolution trees: semidwarfism transgenes modify gibberellins, promote root growth, enhance morphological diversity, and reduce competitiveness in hybrid poplar.

    Science.gov (United States)

    Elias, Ani A; Busov, Victor B; Kosola, Kevin R; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W; Rood, Stewart B; Strauss, Steven H

    2012-10-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA(20) and GA(8), in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations.

  20. Specific Gravity of Hybrid Poplars in the North-Central Region, USA: Within-Tree Variability and Site × Genotype Effects

    Directory of Open Access Journals (Sweden)

    Jesse A. Randall

    2013-04-01

    Full Text Available Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees, with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars.

  1. Mycorrhizae of poplars

    Science.gov (United States)

    R. C. Schultz; J. G. Isebrands; P. P. Kormanik

    1983-01-01

    Poplar hybrids, being screened for short-rotation intensive culture, can form ecto-, endo-, or ectendo-mycorrhizae or may be autotrophic. Different sections of the genus Populus tend to be selective in the type of mycorrhizae formed. Knowledge of which types are formed influences the kinds of propagule production, site preparation, and herbicide...

  2. Biomass carbon, nitrogen and phosphorus stocks in hybrid poplar buffers, herbaceous buffers and natural woodlots in the riparian zone on agricultural land.

    Science.gov (United States)

    Fortier, Julien; Truax, Benoit; Gagnon, Daniel; Lambert, France

    2015-05-01

    In many temperate agricultural areas, riparian forests have been converted to cultivated land, and only narrow strips of herbaceous vegetation now buffer many farm streams. The afforestation of these riparian zones has the potential to increase carbon (C) storage in agricultural landscapes by creating a new biomass sink for atmospheric CO2. Occurring at the same time, the storage of nitrogen (N) and phosphorus (P) in plant biomass, is an important water quality function that may greatly vary with types of riparian vegetation. The objectives of this study were (1) to compare C, N and P storage in aboveground, belowground and detrital biomass for three types of riparian vegetation cover (9-year-old hybrid poplar buffers, herbaceous buffers and natural woodlots) across four agricultural sites and (2) to determine potential vegetation cover effects on soil nutrient supply rate in the riparian zone. Site level comparisons suggest that 9-year-old poplar buffers have stored 9-31 times more biomass C, 4-10 times more biomass N, and 3-7 times more biomass P than adjacent non managed herbaceous buffers, with the largest differences observed on the more fertile sites. The conversion of these herbaceous buffers to poplar buffers could respectively increase C, N and P storage in biomass by 3.2-11.9 t/ha/yr, 32-124 kg/ha/yr and 3.2-15.6 kg/ha/yr, over 9 years. Soil NO3 and P supply rates during the summer were respectively 57% and 66% lower in poplar buffers than in adjacent herbaceous buffers, potentially reflecting differences in nutrient storage and cycling between the two buffer types. Biomass C ranged 49-160 t/ha in woodlots, 33-110 t/ha in poplar buffers and 3-4 t/ha in herbaceous buffers. Similar biomass C stocks were found in the most productive poplar buffer and three of the four woodlots studied. Given their large and varied biomass C stocks, conservation of older riparian woodlots is equally important for C balance management in farmland. In addition, the

  3. Perturbed lignification impacts tree growth in hybrid poplar--a function of sink strength, vascular integrity, and photosynthetic assimilation.

    Science.gov (United States)

    Coleman, Heather D; Samuels, A Lacey; Guy, Robert D; Mansfield, Shawn D

    2008-11-01

    The effects of reductions in cell wall lignin content, manifested by RNA interference suppression of coumaroyl 3'-hydroxylase, on plant growth, water transport, gas exchange, and photosynthesis were evaluated in hybrid poplar trees (Populus alba x grandidentata). The growth characteristics of the reduced lignin trees were significantly impaired, resulting in smaller stems and reduced root biomass when compared to wild-type trees, as well as altered leaf morphology and architecture. The severe inhibition of cell wall lignification produced trees with a collapsed xylem phenotype, resulting in compromised vascular integrity, and displayed reduced hydraulic conductivity and a greater susceptibility to wall failure and cavitation. In the reduced lignin trees, photosynthetic carbon assimilation and stomatal conductance were also greatly reduced, however, shoot xylem pressure potential and carbon isotope discrimination were higher and water-use efficiency was lower, inconsistent with water stress. Reductions in assimilation rate could not be ascribed to increased stomatal limitation. Starch and soluble sugars analysis of leaves revealed that photosynthate was accumulating to high levels, suggesting that the trees with substantially reduced cell wall lignin were not carbon limited and that reductions in sink strength were, instead, limiting photosynthesis.

  4. Altering carbon allocation in hybrid poplar (Populus alba × grandidentata) impacts cell wall growth and development.

    Science.gov (United States)

    Unda, Faride; Kim, Hoon; Hefer, Charles; Ralph, John; Mansfield, Shawn D

    2016-12-20

    Galactinol synthase is a pivotal enzyme involved in the synthesis of the raffinose family of oligosaccharides (RFOs) that function as transport carbohydrates in the phloem, as storage compounds in sink tissues and as soluble metabolites that combat both abiotic and biotic stress in several plant species. Hybrid poplar (Populus alba × grandidentata) overexpressing the Arabidopsis thaliana GolS3 (AtGolS3) gene showed clear effects on development; the extreme overexpressing lines were stunted and had cell wall traits characteristic of tension wood, whereas lines with only moderate up-regulation grew normally and had moderately altered secondary cell wall composition and ultrastructure. Stem cross-sections of the developing xylem revealed a significant increase in the number of vessels, as well as the clear presence of a G-layer in the fibres. Furthermore, AtGolS3-OE lines possessed higher cellulose and lower lignin contents, an increase in cellulose crystallinity, and significantly altered hemicellulose-derived carbohydrates, notably manifested by their mannose and xylose contents. In addition, the transgenic plants displayed elevated xylem starch content. Transcriptome interrogation of the transgenic plants showed a significant up-regulation of genes involved in the synthesis of myo-inositol, along with genes involved in sucrose degradation. The results suggest that the overexpression of GolS and its product galactinol may serve as a molecular signal that initiates metabolic changes, culminating in a change in cell wall development and potentially the formation of tension wood.

  5. Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies.

    Science.gov (United States)

    Ayub, Suleman; Gentet, Luc J; Fiáth, Richárd; Schwaerzle, Michael; Borel, Mélodie; David, François; Barthó, Péter; Ulbert, István; Paul, Oliver; Ruther, Patrick

    2017-09-01

    This article reports on the development, i.e., the design, fabrication, and validation of an implantable optical neural probes designed for in vivo experiments relying on optogenetics. The probes comprise an array of ten bare light-emitting diode (LED) chips emitting at a wavelength of 460 nm and integrated along a flexible polyimide-based substrate stiffened using a micromachined ladder-like silicon structure. The resulting mechanical stiffness of the slender, 250-μm-wide, 65-μm-thick, and 5- and 8-mm-long probe shank facilitates its implantation into neural tissue. The LEDs are encapsulated by a fluropolymer coating protecting the implant against the physiological conditions in the brain. The electrical interface to the external control unit is provided by 10-μm-thick, highly flexible polyimide cables making the probes suitable for both acute and chronic in vivo experiments. Optical and electrical properties of the probes are reported, as well as their in vivo validation in acute optogenetic studies in transgenic mice. The depth-dependent optical stimulation of both excitatory and inhibitory neurons is demonstrated by altering the brain activity in the cortex and the thalamus. Local network responses elicited by 20-ms-long light pulses of different optical power (20 μW and 1 mW), as well as local modulation of single unit neuronal activity to 1-s-long light pulses with low optical intensity (17 μW) are presented. The ability to modulate neural activity makes these devices suitable for a broad variety of optogenetic experiments.

  6. Transcriptome profiles of hybrid poplar (Populus trichocarpa × deltoides) reveal rapid changes in undamaged, systemic sink leaves after simulated feeding by forest tent caterpillar (Malacosoma disstria).

    Science.gov (United States)

    Philippe, Ryan N; Ralph, Steven G; Mansfield, Shawn D; Bohlmann, Jörg

    2010-11-01

    Poplar has been established as a model tree system for genomic research of the response to biotic stresses. This study describes a series of induced transcriptome changes and the associated physiological characterization of local and systemic responses in hybrid poplar (Populus trichocarpa × deltoides) after simulated herbivory. • Responses were measured in local source (LSo), systemic source (SSo), and systemic sink (SSi) leaves following application of forest tent caterpillar (Malacosoma disstria) oral secretions to mechanically wounded leaves. • Transcriptome analyses identified spatially and temporally dynamic, distinct patterns of local and systemic gene expression in LSo, SSo and SSi leaves. Galactinol synthase was strongly and rapidly upregulated in SSi leaves. Genome analyses and full-length cDNA cloning established an inventory of poplar galactinol synthases. Induced changes of galactinol and raffinose oligosaccharides were detected by anion-exchange high-pressure liquid chromatography. • The LSo leaves showed a rapid and strong transcriptome response compared with a weaker and slower response in adjacent SSo leaves. Surprisingly, the transcriptome response in distant, juvenile SSi leaves was faster and stronger than that observed in SSo leaves. Systemic transcriptome changes of SSi leaves have signatures of rapid change of metabolism and signaling, followed by later induction of defense genes.

  7. Characterization of hemizygous deletions in citrus using array-comparative genomic hybridization and microsynteny comparisons with the poplar genome.

    Science.gov (United States)

    Ríos, Gabino; Naranjo, Miguel A; Iglesias, Domingo J; Ruiz-Rivero, Omar; Geraud, Marion; Usach, Antonio; Talón, Manuel

    2008-08-09

    Many fruit-tree species, including relevant Citrus spp varieties exhibit a reproductive biology that impairs breeding and strongly constrains genetic improvements. In citrus, juvenility increases the generation time while sexual sterility, inbreeding depression and self-incompatibility prevent the production of homozygous cultivars. Genomic technology may provide citrus researchers with a new set of tools to address these various restrictions. In this work, we report a valuable genomics-based protocol for the structural analysis of deletion mutations on an heterozygous background. Two independent fast neutron mutants of self-incompatible clementine (Citrus clementina Hort. Ex Tan. cv. Clemenules) were the subject of the study. Both mutants, named 39B3 and 39E7, were expected to carry DNA deletions in hemizygous dosage. Array-based Comparative Genomic Hybridization (array-CGH) using a Citrus cDNA microarray allowed the identification of underrepresented genes in these two mutants. Subsequent comparison of citrus deleted genes with annotated plant genomes, especially poplar, made possible to predict the presence of a large deletion in 39B3 of about 700 kb and at least two deletions of approximately 100 and 500 kb in 39E7. The deletion in 39B3 was further characterized by PCR on available Citrus BACs, which helped us to build a partial physical map of the deletion. Among the deleted genes, ClpC-like gene coding for a putative subunit of a multifunctional chloroplastic protease involved in the regulation of chlorophyll b synthesis was directly related to the mutated phenotype since the mutant showed a reduced chlorophyll a/b ratio in green tissues. In this work, we report the use of array-CGH for the successful identification of genes included in a hemizygous deletion induced by fast neutron irradiation on Citrus clementina. The study of gene content and order into the 39B3 deletion also led to the unexpected conclusion that microsynteny and local gene colinearity in

  8. Characterization of hemizygous deletions in Citrus using array-Comparative Genomic Hybridization and microsynteny comparisons with the poplar genome

    Directory of Open Access Journals (Sweden)

    Usach Antonio

    2008-08-01

    Full Text Available Abstract Background Many fruit-tree species, including relevant Citrus spp varieties exhibit a reproductive biology that impairs breeding and strongly constrains genetic improvements. In citrus, juvenility increases the generation time while sexual sterility, inbreeding depression and self-incompatibility prevent the production of homozygous cultivars. Genomic technology may provide citrus researchers with a new set of tools to address these various restrictions. In this work, we report a valuable genomics-based protocol for the structural analysis of deletion mutations on an heterozygous background. Results Two independent fast neutron mutants of self-incompatible clementine (Citrus clementina Hort. Ex Tan. cv. Clemenules were the subject of the study. Both mutants, named 39B3 and 39E7, were expected to carry DNA deletions in hemizygous dosage. Array-based Comparative Genomic Hybridization (array-CGH using a Citrus cDNA microarray allowed the identification of underrepresented genes in these two mutants. Subsequent comparison of citrus deleted genes with annotated plant genomes, especially poplar, made possible to predict the presence of a large deletion in 39B3 of about 700 kb and at least two deletions of approximately 100 and 500 kb in 39E7. The deletion in 39B3 was further characterized by PCR on available Citrus BACs, which helped us to build a partial physical map of the deletion. Among the deleted genes, ClpC-like gene coding for a putative subunit of a multifunctional chloroplastic protease involved in the regulation of chlorophyll b synthesis was directly related to the mutated phenotype since the mutant showed a reduced chlorophyll a/b ratio in green tissues. Conclusion In this work, we report the use of array-CGH for the successful identification of genes included in a hemizygous deletion induced by fast neutron irradiation on Citrus clementina. The study of gene content and order into the 39B3 deletion also led to the unexpected

  9. The low fertility of Chinese white poplar: dynamic changes in anatomical structure, endogenous hormone concentrations, and key gene expression in the reproduction of a naturally occurring hybrid.

    Science.gov (United States)

    Ma, Kaifeng; Song, Yuepeng; Huang, Zhen; Lin, Liyuan; Zhang, Zhiyi; Zhang, Deqiang

    2013-03-01

    KEY MESSAGE : We report that low fertility during intraspecific hybridization in Chinese white poplar was caused by prefertilization barriers, reduced ovules, and embryonic abortion. Hormone concentrations and gene expression patterns were also evaluated during the fertilization process. Hybrid vigor holds tremendous potential for yield increases and trait improvement; however, some hybridization combinations within Populus show very low fertility. To explore the causes of this low fertility in intraspecific hybridization of Chinese white poplar, we examined anatomical structure, hormone levels and expression of key genes in two unique crossing combinations of Populus × tomentosa "Pt02" × P. × tomentosa "LM50", and (P. × tomentosa × P. alba cv. bolleana "Ptb") × P. × tomentosa "LM50". The seed set potential in the intraspecific hybridization P. × tomentosa "Pt02" × P. × tomentosa "LM50" was quite low, which was likely caused by prefertilization barriers, reduced ovule numbers, and embryonic abortion in ovaries. During intraspecific hybridization, we found reduced indoleacetic acid (IAA) in pistils, which may cause pollen tube deformations and increased IAA in heart-stage embryos, which may affect embryo development. Gibberellin A3 (GA3) decreased from the zygote dormancy stage to globular-stage embryos, which may be caused by failure of fertilization in specific embryos. The maximum zeatin (Z) concentration was found in heart-stage embryos, but Z concentrations quickly decreased, which may affect endosperm development. Increasing concentrations of abscisic acid (ABA) during zygote dormancy and eight-cell proembryo stages likely induced abscission of the infructescence. High ABA concentrations also regulated embryo maturity. Measurement of genes expression showed that high expression of SRK and/or SLG may result in rejection of pollen by stigmatic papillae through a mechanism, reminiscent of self-incompatibility. Also, low expression of

  10. Improvement of controlled pollination techniques of poplar

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhong-cheng; LIU Zong-you; HOU Kai-ju; SUN Xian-meng; ZHANG Ji-he; SHEN Bao-xian

    2008-01-01

    Over a number of years, in order to find substitutes for two traditional poplar pollination techniques: outdoor bridging trees and indoor cutting with water culture, research into two new pollination methods of uprooted outdoor seed trees and outdoor cutting branches was carried out. The advantages of two new and improved techniques were of efficiency, economy, safety and ease of operation. The methods can be applied in hybridization and breeding of poplar and other easy-to-root trees.

  11. 混栽模式下转基因741杨抗虫性的初步研究%Studies on the insect resistance of mixed cultivating model of transgenic insect- resistance hybrid poplar 741

    Institute of Scientific and Technical Information of China (English)

    李超丽; 刘军侠; 姜文虎

    2011-01-01

    采用随机取样的方法,对河北省保定市大激店混栽模式下不同株系的转基因741杨pb29、pb00、pb17及对照741杨试验林进行了节肢动物群落调查,并初步分析了其群落组成、物种数量随时间的变化及优势种的发生发展规律.结果表明:混栽模式F的转基因741杨pb29、pb11和pb17的节肢动物种类组成基本一致,其群落多样性、均匀性均高于对照杨树,优势集中性均低于对照杨树,稳定性较好.混栽转基因741杨林内的优势种异色瓢虫、白毛蚜和杨白潜叶蛾在不同株系卜发生趋势基本一致,且在对照杨树上虫口数量较高.%The arthropod community structure was investigated in different transgenic hybrid poplar 741 varieties including pb29,pbll,pb17 and check741 using random sampling method in the paper. The purpose of this study is to analysis the changes over time about the structure of the arthropod community and the species quantity , the law of development of dominant species. The results showed that eompositive species were similar among the different transgenic hybrid poplar 741 varieties in this mixed cultivating model, the diversity indexes and evenness indexes of arthropod community in transgenic 741 poplar were higher than the control 741 poplar. The dominant value indexes were lower than the control 741 poplar,and the stability was better. The dominant species in this arthropod connunity including Harmonia axyridis Pallas, Chaitophoms populialbae Boyer de Fonscolombe and Leucoptera susinella Herrich- Sch ffer had similarly changing tendency, though they had a large quantity in the control 741 poplar.

  12. Effects of mechanical damage and herbivore wounding on H2O2 metabolism and antioxidant enzyme activities in hybrid poplar leaves

    Institute of Scientific and Technical Information of China (English)

    AN Yu; SHEN Ying-bai; ZHANG Zhi-xiang

    2009-01-01

    The changes of hydrogen peroxide (H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar (Populus simonii ×P. pyramidalis ‘Opera 8277') in response to mechanical damage (MD) and herbivore wounding (HW) were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance. Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves. The activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were also enhanced. However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI (which is a specific inhibitor of NADPH oxidase). The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities. A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.

  13. Ozone sensitivity in hybrid poplar correlates with insensitivity to both salicylic acid and jasmonic acid. The role of programmed cell death in lesion formation.

    Science.gov (United States)

    Koch, J R; Creelman, R A; Eshita, S M; Seskar, M; Mullet, J E; Davis, K R

    2000-06-01

    Our earlier studies demonstrated that the ozone-sensitive hybrid poplar clone NE-388 displays an attenuated level of ozone-, wound-, and phytopathogen-induced defense gene expression. To determine if this reduced gene activation involves signal transduction pathways dependent on salicylic acid (SA) and/or jasmonic acid (JA), we compared the responses of NE-388 and an ozone-tolerant clone, NE-245, to these signal molecules. JA levels increased in both clones in response to ozone, but only minimal increases in SA levels were measured for either clone. Treatment with SA and methyl jasmonate induced defense gene expression only in NE-245, indicating that NE-388 is insensitive to these signal molecules. DNA fragmentation, an indicator of programmed cell death (PCD), was detected in NE-245 treated with either ozone or an avirulent phytopathogen, but was not detected in NE-388. We conclude that these clones undergo two distinct mechanisms of ozone-induced lesion formation. In NE-388, lesions appear to be due to toxic cell death resulting from a limited ability to perceive and subsequently activate SA- and/or JA-mediated antioxidant defense responses. In NE-245, SA-dependent PCD precedes lesion formation via a process related to the PCD pathway activated by phytopathogenic bacteria. These results support the hypothesis that ozone triggers a hypersensitive response.

  14. Ozone-induced changes in photosynthesis and photorespiration of hybrid poplar in relation to the developmental stage of the leaves.

    Science.gov (United States)

    Bagard, Matthieu; Le Thiec, Didier; Delacote, Emilien; Hasenfratz-Sauder, Marie-Paule; Banvoy, Jacques; Gérard, Joëlle; Dizengremel, Pierre; Jolivet, Yves

    2008-12-01

    Young poplar trees (Populus tremula Michx. x Populus alba L. clone INRA 717-1B4) were subjected to 120 ppb of ozone for 35 days in phytotronic chambers. Treated trees displayed precocious leaf senescence and visible symptoms of injury (dark brown/black upper surface stippling) exclusively observed on fully expanded leaves. In these leaves, ozone reduced parameters related to photochemistry (Chl content and maximum rate of photosynthetic electron transport) and photosynthetic CO(2) fixation [net CO(2) assimilation, Rubisco (ribulose-1,5-bisphosphate carboxylase oxygenase) activity and maximum velocity of Rubisco for carboxylation]. In fully expanded leaves, the rate of photorespiration as estimated from Chl fluorescence was markedly impaired by the ozone treatment together with the activity of photorespiratory enzymes (Rubisco and glycolate oxidase). Immunoblot analysis revealed a decrease in the content of serine hydroxymethyltransferase in treated mature leaves, while the content of the H subunit of the glycine decarboxylase complex was not modified. Leaves in the early period of expansion were exempt from visible symptoms of injury and remained unaffected as regards all measured parameters. Leaves reaching full expansion under ozone exposure showed potential responses of protection (stimulation of mitochondrial respiration and transitory stomatal closure). Our data underline the major role of leaf phenology in ozone sensitivity of photosynthetic processes and reveal a marked ozone-induced inhibition of photorespiration.

  15. Microarray and suppression subtractive hybridization analyses of gene expression in hybrid poplar (Populus alba × Populus tremula var. glandulosa) cell suspension cultures after exposure to NaCl.

    Science.gov (United States)

    Bae, Eun-Kyung; Lee, Hyoshin; Lee, Jae-Soon; Noh, Eun-Woon; Choi, Young-Im; Lee, Byung-Hyun; Choi, Dong-Woog

    2012-09-01

    The gene expression profiles of hybrid poplar (Populus alba × Populus tremula var. glandulosa) cells in suspension culture after exposure to salinity (NaCl) induced stress were examined by constructing two suppression subtractive hybridization (SSH) libraries. cDNA from non-treated cells was used as a driver and cDNA samples from cell suspension cultures exposed to 150 mM NaCl for 2 or 10 h were used as testers. Randomly selected clones from each SSH library were sequenced and 727 high-quality expressed sequence tags (ESTs) were obtained and analyzed. Four novel ESTs were identified. Between the two libraries, 542 unique SSH clones were selected for placement on a cDNA microarray. In total, 18 differentially expressed genes were identified with 4 and 12 genes being significantly differentially expressed 2 and 10 h after the treatment, respectively. Genes related to metabolism and protein synthesis and several genes whose protein products are implicated in salt or other abiotic stress-related responses were expressed in the salt-stressed cells.

  16. Responses of hybrid poplar clones and red maple seedlings to ambient O(3) under differing light within a mixed hardwood forest.

    Science.gov (United States)

    Wei, C; Skelly, J M; Pennypacker, S P; Ferdinand, J A; Savage, J E; Stevenson, R E; Davis, D D

    2004-07-01

    The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O(3)) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O(3) concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O(3) concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 micromol m(-2) s(-1), respectively. Ambient O(3) exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001 growing season. Percentage of total leaf area affected (%LAA) was positively correlated with cumulative O(3) exposures. More severe foliar injury was observed on plants grown within the full shade and partial shade plots than those observed on plants grown within the sun plot. Lower light availability within the partial shade and full shade plots significantly decreased net photosynthetic rate (Pn) and stomatal conductance (g(wv)). The reductions in Pn were greater than reductions in g(wv), which resulted in greater O(3) uptake per unit Pn in plants grown within the partial shade and full shade plots. Greater O(3) uptake per unit Pn was consistently associated with more severe visible foliar injury in all species and/or clones regardless of differences in shade tolerance. These studies suggest that plant physiological responses to O(3) exposure are likely complicated due to multiple factors under natural forest conditions.

  17. Transformation of spider neurotoxin gene with prospective insecticidal properties into hybrid poplar Populus simonii × P. nigra%向小黑杨转化蜘蛛杀虫毒素基因

    Institute of Scientific and Technical Information of China (English)

    林同; 王志英; 刘宽余; 景天忠; 张传溪

    2006-01-01

    In recent years, the pest insects on hybrid poplar Populus simonii × P. nigra broke out heavily, which caused great losses in forestry. In order to improve insect resistance of P. simonii × P. nigra and avoid pollution due to insecticides, the fused BGT gene consisting of the insecticidal toxin gene from the spider, Atrax robustus, and the C terminal of Cry Ⅰ A (b) gene from Bacillus thuringiensis was transferred into P. simonii × P. nigra by Agrobacteriumm-mediated transformation system. The results of PCR and Southern blotting analyses showed that the insecticidal gene of BGT was integrated into the genome of P. simonii × P. nigra. The corrected mortality of the second instar of Lymantria dispar in 6 days and 9 days after they were fed with the transgenic poplars was 37.0% and92.6% , respectively. Analysis of variance showed that there was significant difference in body weight between L. dispar larvae fed with the transformed poplars and those fed with untransformed poplars. The results indicated that the growth rate of L. dispar fed with the transgenic poplars was affected negatively.%近年来,危害小黑杨Populus simonii×P.nigra的害虫发生严重,给林业生产造成很大损失.为了提高小黑杨的抗虫能力,避免使用杀虫剂带来的污染,用农杆菌介导法将澳大利亚漏斗蛛Atrax robustus的毒蛋白基因和苏云金芽孢杆菌Cry Ⅰ A(b)基因C末端的融合基因BGT转化入小黑杨.PCR和Southern印记分析转基因植株,结果表明,BGT杀虫基因已经整合在小黑杨基因组上.活性实验表明,取食转基因杨树6天和9天后,舞毒蛾Lymantria dispar 2龄幼虫的校正死亡率分别是37.0%和92.6%.方差分析表明取食转基因和对照杨树的舞毒蛾幼虫体重差异显著.这些结果显示转基因杨树上的舞毒蛾的发育速率受到影响.

  18. Developing xylem-preferential expression of PdGA20ox1, a gibberellin 20-oxidase 1 from Pinus densiflora, improves woody biomass production in a hybrid poplar.

    Science.gov (United States)

    Jeon, Hyung-Woo; Cho, Jin-Seong; Park, Eung-Jun; Han, Kyung-Hwan; Choi, Young-Im; Ko, Jae-Heung

    2016-04-01

    Woody biomass has gained popularity as an environmentally friendly, renewable and sustainable resource for liquid fuel production. Here, we demonstrate biotechnological improvement of the quantity and quality of woody biomass by employing developing xylem (DX)-preferential production of gibberellin (GA), a phytohormone that positively regulates stem growth. First, for the proof of concept experiment, we produced transgenic Arabidopsis plants expressing GA20-oxidase, a key enzyme in the production of bioactive GAs, from Pinus densiflora (PdGA20ox1) under the control of either a constitutive 35S promoter, designated 35S::PdGA20ox1, or a DX-specific promoter (originated from poplar), designated DX15::PdGA20ox1. As we hypothesized, both transgenic Arabidopsis plants (35S::PdGA20ox1 and DX15::PdGA20ox1) exhibited an accelerated stem growth that resulted in a large increase of biomass, up to 300% compared to wild-type control plants, together with increased secondary wall thickening and elongation of fibre cells. Next, we applied our concept to the production of transgenic poplar trees. Both transgenic poplar trees (35S::PdGA20ox1 and DX15::PdGA20ox1) showed dramatic increases in biomass, up to 300%, with accelerated stem growth and xylem differentiation. Cell wall monosaccharide composition analysis revealed that in both Arabidopsis and poplar, glucose and xylose contents were significantly increased. However, undesirable phenotypes of 35S::PdGA20ox1 poplar, including poor root growth and leaf development, were found. Interestingly, DX15::PdGA20ox1 poplar resulted in a reduction of undesirable phenotypes. Our results indicate that the controlled production of GAs through a tissue-specific promoter can be utilized as an efficient biotechnological tool for producing enhanced plant biomass, minimizing unwanted effects.

  19. Effects of in vitro ozone treatment on proteolysis of purified rubisco from two hybrid poplar clones. [Populus maximowizii x trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    Landry, L.G.; Pell, E.J. (Pennsylvania State Univ., University Park (USA))

    1989-04-01

    Plants exposed to ozone (O{sub 3}) exhibited symptoms of premature senescence, including early decline in quantity of rubisco. O{sub 3}-induced oxidation may cause changes in protein conformation of rubisco, resulting in enhanced proteolysis. To test this hypothesis, rubisco was purified from two hybrid clones of Populus maximowizii x trichocarpa, clones 388 and 245, and treated in vitro with O{sub 3} or air. Rubisco was then challenged with bromelain, papain, chymotrypsin, carboxypeptidase A, or endoproteinase Glu-C and percent degradation measured by SDS-PAGE and densitometric scanning of the gels. Degree of rubisco sensitivity to oxidation may be related to available sulfhydryl (SH) groups on the protein. The number of SH groups in native and denatured rubisco was measured for purified rubisco of both clones by DTNB titration method. The relationship between sensitivity to proteolysis and number and availability of SH groups is discussed.

  20. Gaseous NO2 effects on epidermis and stomata related physiochemical characteristics of hybrid poplar leaves: chemical elements composition, stomatal functions, photosynthesis and respiration

    Science.gov (United States)

    Mechanisms controlling effects of gaseous nitrogen dioxide on epidermis and stomata dynamics, and photosynthesis and respirations processes are still not fully understood. In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (4 microliters per lite...

  1. Overexpression of gibberellin 20-oxidase1 from Pinus densiflora results in enhanced wood formation with gelatinous fiber development in a transgenic hybrid poplar.

    Science.gov (United States)

    Park, Eung-Jun; Kim, Hyun-Tae; Choi, Young-Im; Lee, Chanhui; Nguyen, Van Phap; Jeon, Hyung-Woo; Cho, Jin-Seong; Funada, Ryo; Pharis, Richard P; Kurepin, Leonid V; Ko, Jae-Heung

    2015-11-01

    Gibberellins (GAs) are important regulators of plant shoot biomass growth, and GA 20-oxidase (GA20ox) is one of the major regulatory enzymes in the GA biosynthetic pathway. Previously, we showed that the expression levels of a putative GA20ox1 (i.e., PdGA20ox1) in stem tissue of 3-month-old seedlings of 12 families of Pinus densiflora were positively correlated with stem diameter growth across those same families growing in an even-aged 32-year-old pine forest (Park EJ, Lee WY, Kurepin LV, Zhang R, Janzen L, Pharis RP (2015) Plant hormone-assisted early family selection in Pinus densiflora via a retrospective approach. Tree Physiol 35:86-94). To further investigate the molecular function of this gene in the stem wood growth of forest trees, we produced transgenic poplar lines expressing PdGA20ox1 under the control of the 35S promoter (designated as 35S::PdGA20ox1). By age 3 months, most of the 35S::PdGA20ox1 poplar trees were showing an exceptional enhancement of stem wood growth, i.e., up to fourfold increases in stem dry weight, compared with the nontransformed control poplar plants. Significant increases in endogenous GA1, its immediate precursor (GA20) and its catabolite (GA8) in elongating internode tissue accompanied the increased stem growth in the transgenic lines. Additionally, the development of gelatinous fibers occurred in vertically grown stems of the 35S::PdGA20ox1 poplars. An analysis of the cell wall monosaccharide composition of the 35S::PdGA20ox1 poplars showed significant increases in xylose and glucose contents, indicating a qualitative increase in secondary wall depositions. Microarray analyses led us to find a total of 276 probe sets that were upregulated (using threefold as a threshold) in the stem tissues of 35S::PdGA20ox1 poplars relative to the controls. 'Cell organization or biogenesis'- and 'cell wall'-related genes were overrepresented, including many of genes that are involved in cell wall modification. Several transcriptional

  2. Overexpression of PtrMYB119, a R2R3-MYB transcription factor from Populus trichocarpa, promotes anthocyanin production in hybrid poplar.

    Science.gov (United States)

    Cho, Jin-Seong; Nguyen, Van Phap; Jeon, Hyung-Woo; Kim, Min-Ha; Eom, Seok Hyun; Lim, You Jin; Kim, Won-Chan; Park, Eung-Jun; Choi, Young-Im; Ko, Jae-Heung

    2016-09-01

    Anthocyanins are a group of colorful and bioactive natural pigments with important physiological and ecological functions in plants. We found an MYB transcription factor (PtrMYB119) from Populus trichocarpa that positively regulates anthocyanin production when expressed under the control of the CaMV 35S promoter in transgenic Arabidopsis Amino acid sequence analysis revealed that PtrMYB119 is highly homologous to Arabidopsis PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT1), a well-known transcriptional activator of anthocyanin biosynthesis. Independently produced transgenic poplars overexpressing PtrMYB119 or PtrMYB120 (a paralogous gene to PtrMYB119) (i.e., 35S::PtrMYB119 and 35S::PtrMYB120, respectively) showed elevated accumulation of anthocyanins in the whole plants, including leaf, stem and even root tissues. Using a reverse-phase high-performance liquid chromatography, we confirmed that the majority of the accumulated anthocyanin in our transgenic poplar is cyanidin-3-O-glucoside. Gene expression analyses revealed that most of the genes involved in the anthocyanin biosynthetic pathway were highly upregulated in 35S::PtrMYB119 poplars compared with the nontransformed control poplar. Among these genes, expression of PtrCHS1 (Chalcone Synthase1) and PtrANS2 (Anthocyanin Synthase2), which catalyze the initial and last steps of anthocyanin biosynthesis, respectively, was upregulated by up to 350-fold. Subsequent transient activation assays confirmed that PtrMYB119 activated the transcription of both PtrCHS1 and PtrANS2 Interestingly, expression of MYB182, a repressor of both anthocyanin and proanthocyanidin (PA) biosynthesis, was largely suppressed in 35S::PtrMYB119 poplars, while expression of MYB134, an activator of PA biosynthesis, was not changed significantly. More interestingly, high-level accumulation of anthocyanins in 35S::PtrMYB119 poplars did not have an adverse effect on plant growth. Taken together, our results demonstrate that PtrMYB119 and PtrMYB120

  3. Dinamica şi caracteristicile creşterii a şase clone de plop hibrid pe parcursul unui ciclu de producţie într-o plantație comparativă din Depresiunea Rădăuţi [The dynamics and growth characteristics of six hybrid poplar clones during a production cycle in a comparative plantation from Rădăuți Depression

    Directory of Open Access Journals (Sweden)

    Dănilă Iulian

    2015-08-01

    Full Text Available The poplar (Populus spp. plays an important role in worldwide forest economy, responding to the necessities of obtaining high biomass production in a short time. Short rotation forests (SRF are developing continuously in Romania. Several studies have been undertaken to identify the clones with high productivity and suitable technologies. The aim of this study was to register the annual increments in diameter, height and volume in an experimental poplar crops with a short-term rotation of 5 years. The poplar cultures are composed from 6 types of hybrid poplar clones (AF2, AF6, Monviso, A4A, Pannonia and Max4 with a density of 2667 trees ha-1. The research results show a clear differentiation among clones’ increments. The highest increments were obtained with AF2 and AF6 clones in five years, with almost 0.038 m3 an-1. The lowest increment was observed for Max4 clone with 0.028 m3.

  4. Contrasting colonization and plant growth promoting capacity between wild type and gfp-derative of the endophyte Pseudomonas putida W619 in hybrid poplar

    Energy Technology Data Exchange (ETDEWEB)

    Weyens N.; van der Lelie D.; Boulet, J.; Adriaensen, D.; Timmermans, J.-P.; Prinsen, E.; Van Oevelen, S.; D" Haen, J.; Smeets, K.; Taghavi, S.; Vangronsveld, J.

    2011-06-09

    This study aims to investigate the colonization of poplar by the endophyte Pseudomonas putida W619 and its capacity to promote plant growth. Poplar cuttings were inoculated with P. putida W619 (wild-type or gfp-labelled). The colonization of both strains was investigated and morphological, physiological and biochemical parameters were analyzed to evaluate plant growth promotion. Inoculation with P. putida W619 (wild-type) resulted in remarkable growth promotion, decreased activities of antioxidative defence related enzymes, and reduced stomatal resistance, all indicative of improved plant health and growth in comparison with the non-inoculated cuttings. In contrast, inoculation with gfp-labelled P. putida W619 did not promote growth; it even had a negative effect on plant health and growth. Furthermore, compared to the wildtype strain, colonization by the gfp-labelled P. putida W619::gfp1 was much lower; it only colonized the rhizosphere and root cortex while the wild-type strain also colonized the root xylem vessels. Despite the strong plant growth promoting capacity of P. putida W619 (wild-type), after gfp labelling its growth promoting characteristics disappeared and its colonization capacity was strongly influenced; for these reasons gfp labelling should be applied with sufficient caution.

  5. On barely continuous functions

    Directory of Open Access Journals (Sweden)

    Richard Stephens

    1988-01-01

    Full Text Available The term barely continuous is a topological generalization of Baire-1 according to F. Gerlits of the Mathematical Institute of the Hungarian Academy of Sciences, and thus worthy of further study. This paper compares barely continuous functions and continuous functions on an elementary level. Knowing how the continuity of the identity function between topologies on a given set yields the lattice structure for those topologies, the barely continuity of the identity function between topologies on a given set is investigated and used to add to the structure of that lattice. Included are certain sublattices generated by the barely continuity of the identity function between those topologies. Much attention is given to topologies on finite sets.

  6. Efectul aplicării lucrărilor de întreținere a terenului asupra acumulărilor de biomasă din culturile de plop hibrid [The effect of harrowing and weed control on biomass yields of hybrid poplar crops

    Directory of Open Access Journals (Sweden)

    Avăcăriței D

    2016-12-01

    Full Text Available Intensive hybrid poplar crops can produce an important biomass if adequate measures of management are being used. During the last years, there is a constant involvement on refining poplar cultivation technology, regarding installation, maintenance and harvesting, in order to obtain superior production at lower costs. The present study has analysed the effect of an experimental maintaining treatment (TI (harrowing and weed control on poplar crops’ biomass yields. The results were obtained after two vegetation seasons and compared with the results recorded in a control plot where no maintaining practices (TN were used. The experimental crop was set up in the spring of 2013, in the vicinity of Dornești site (Suceava County. Three hybrid poplar clones were tested (AF2, AF8 and Pannonia in each plot, and there were installed by long rods, using the 3.0 x 1.5 m spacing. The biomass was assessed for all the harvested individuals and every tree component using the gravimetric method. The experimental maintaining treatment (TI led to important differences between the two plots. The total biomass in TI plot was nearly eight-times superior to the biomass obtained in the control plot. All the three clones reacted significantly to the experimental treatment TI, even though minor differences were observed between the clones’ productivity. The effect of TI treatment was also substantial to the biomass’ structure on tree components. It is considered that the massive biomass increase was encouraged by a consistent shift of biomass proportion in the favour of the crown proportion (branches biomass, rather than subterranean elements.

  7. 转抗虫基因杨树对土壤微生物影响分析%Effects of transgenic insect-resistance hybrid poplar 741 groves on soil microorganisms

    Institute of Scientific and Technical Information of China (English)

    甄志先; 王进茂; 杨敏生

    2011-01-01

    In order to evaluate ecologic safety of transgenic insect-resistance hybrid poplar 741,the diversity of soil microflora and Bt toxin protein were systematically studied in the growth season. 4-year-old transgenic poplar 741 in the Heneshui district and Baoding district were examined. The toxin protein was found in the soil of 4-year-old test groves, whose peak content appeared in rhizosphere, and the longer the distances off the roots, the lower the contents.The distribution of toxin protein showed a descending trend: root tissue> root surface soil>rhizosphere soil> surface soil. The concentration of toxin protein decreased by degree of 10 times among different parts of soil. No toxin protein was found in rhizosphere of non-transformed clones. In the rhizosphere and roots surface soil of 4-year-old test groves, the amount of bacteria and actinomycetes and fungi varied with the changes of season. In spring, their amount began to increase gradually, reaching the maximum in June and July, and then decreased gradually. Between different transgenic clones and nontransgenic controls, during different seasons there were differences but no significant difference of their amounts appeared in rhizosphere and roots surface soil. The existence of toxin protein in soil showed no significant influence on the amounts of fungi, bacteria and actinomycetes. The result showed that distribution of Bt toxin protein was not related to the amount of microorganism. Transgenic poplar is ecofriendly in the grittiness soil.%以4年生转双抗虫基因741杨试验林为对象,研究了土壤中Bt毒蛋白的分布,及其在生长季节中土壤微生物种群数量的变化.结果表明:试验林土壤中发现了毒蛋白的存在,在转基因植株根围含量最高,距根系越远,含量逐渐降低.其毒蛋白分布趋势是根组织>根际土壤>根围土壤>地表土,其浓度一般呈10倍的等级降低,在非转基因对照植株根系周围未检

  8. Sequencing the genome of Marssonina brunnea reveals fungus-poplar co-evolution

    Directory of Open Access Journals (Sweden)

    Zhu Sheng

    2012-08-01

    Full Text Available Abstract Background The fungus Marssonina brunnea is a causal pathogen of Marssonina leaf spot that devastates poplar plantations by defoliating susceptible trees before normal fall leaf drop. Results We sequence the genome of M. brunnea with a size of 52 Mb assembled into 89 scaffolds, representing the first sequenced Dermateaceae genome. By inoculating this fungus onto a poplar hybrid clone, we investigate how M. brunnea interacts and co-evolves with its host to colonize poplar leaves. While a handful of virulence genes in M. brunnea, mostly from the LysM family, are detected to up-regulate during infection, the poplar down-regulates its resistance genes, such as nucleotide binding site domains and leucine rich repeats, in response to infection. From 10,027 predicted proteins of M. brunnea in a comparison with those from poplar, we identify four poplar transferases that stimulate the host to resist M. brunnea. These transferas-encoding genes may have driven the co-evolution of M. brunnea and Populus during the process of infection and anti-infection. Conclusions Our results from the draft sequence of the M. brunnea genome provide evidence for genome-genome interactions that play an important role in poplar-pathogen co-evolution. This knowledge could help to design effective strategies for controlling Marssonina leaf spot in poplar.

  9. The Globe laid bare

    CERN Multimedia

    Fortunati, Lucien

    2015-01-01

    If you’re at CERN at the moment, you will certainly have noticed the work under way on the Globe. The structure, which has been in pride of place opposite the Laboratory for over ten years, has never been so completely laid bare. But, as we explained in a previous article (see here), it is all for a good cause. The Globe is built entirely from wood and certain parts of it need to be replaced.

  10. The Globe laid bare

    CERN Multimedia

    Fortunati, Lucien

    2015-01-01

    If you’re at CERN at the moment, you will certainly have noticed the work under way on the Globe. The structure, which has been in pride of place opposite the Laboratory for over ten years, has never been so completely laid bare. But, as we explained in a previous article (see here), it is all for a good cause. The Globe is built entirely from wood and certain parts of it need to be replaced.

  11. GROWTH AND PRODUCTIVITY OF POPLAR SPECIES IN SOUTHEASTERN KAZAKHSTAN

    Directory of Open Access Journals (Sweden)

    Dani Sarsekova

    2015-09-01

    Full Text Available A small area of forestation and an acute shortage of timber are reasons to seek ways to improve  productivity and the rational use of forests in the territory of Kazakhstan. A deficit in timber can be compensated, to some extent, by planting stands of fast-growing plantation species, including top and hybrid Populus spp, which are commonly referred to as “poplar”.There is an increased interest in poplar, globally, due to its organic traits and the economic value it provides, including:rapid growth and ability to produce wood that is technically suitable for cutting within 20 years of planting;a source of suitable timber for use in most industries;the ability to grow in soils that are not  generally suitable for agricultural use;a potential source of timber for widespread use in screening, landscape and recreational plantings; andthe ability of most poplar species and hybrids to asexually propagate.There has been extensive planting of poplar trees in Kazakhstan, especially in the south and south-east. Poplar trees have been planted in populated areas, along roads and in forest stands. However, these plantings are unsuitable as a source of timber for commercial or ornamental purposes. Hence, there is a need to establish plantations of poplar for timber supply in Kazakhstan.The  most common types of poplar in this country are the deltoid, Algerian, and Bolle, which were used in the extensive greenery planting of southeastern Kazakhstan. The main factors ensuring high productivity of poplar plantations are the soil conditions of fertility, good aeration and adequate moisture. Results of this study indicate that the greatest height increase occurs in these trees between the age of 5 and 10 years, and for trunk diameter, between the age of 4 and 9 years. After this age, the growth rate gradual declines, with a sharp fall off in the rate noticeable between years 14 and 16. Additionally, results of this study show the high productivity of poplar

  12. 杂交杨木纤维中碳水化合物的稀酸催化分离%Dilute Acid-catalyzed Fractionation of Carbohydrates in Hybrid Poplar Fibers

    Institute of Scientific and Technical Information of China (English)

    张春辉; Troy Runge; 詹怀宇

    2012-01-01

    In this paper, the acid-catalyzed fractionation of pentosans and hexosans from hybrid poplar fibers was studied using a circulation reactor. Kinetic models of both pentosan and hexosan hydrolysis/degradation were crea- ted to predict the hydrolysis yield of both substances. The extraction conditions were varied, including a tempera- ture range of 140 - 170℃ , a sulfuric acid concentration range of 0.1% - 0.9% wt with a constant liquor-to-wood ratio of 6: 1. The yields of both substances were favored at high acid concentration and temperature, while pentosan being considerable more reactive. Under optimal conditions, 91 percent of pentosan could be separated from the fi- ber, while more than 93 percent of hexosan was retained in the solids. This study demonstrates that pentosan and hexosans could be fractionated from poplar fibers using acid hydrolysis and converted into liquid fuel and valued chemicals separately.%本文采用循环式反应器研究了杂交杨木纤维中聚戊糖和聚己糖在稀酸条件下的催化分离,分别得出了聚戊糖和聚己糖稀酸水解/降解的动力学模型,以预测在不同反应条件下戊糖和己糖的水解得率。反应条件为温度140~170℃,硫酸浓度0.1%~0.9%wt,液比为6:1。研究发现,较高的酸浓和温度对提高戊糖和己糖的得率都有利,但相同条件下聚戊糖的反应活性更高。经动力学模型优化得出,在较佳条件下有91%的聚戊糖可以以单体、低聚体及其降解产物的形式从杨木纤维中分离出来,同时超过93%的聚己糖可以以固体的形式保留在纤维中。研究表明,在适宜的稀酸催化条件下杂交杨木纤维中的碳水化合物可以得到很好的分离,为下一步戊糖和聚己糖的分别单独转化打下了基础,不仅可以充分利用木材生物质资源,而且为反应提供了相对均一的条件,从而提高反应选择性和产物的纯度。

  13. Molecular Dissection of Xylan Biosynthesis during Wood Formation in Poplar

    Institute of Scientific and Technical Information of China (English)

    Chanhui Lee; Quincy Teng; Ruiqin Zhong; Zheng-Hua Ye

    2011-01-01

    Xylan, being the second most abundant polysaccharide in dicot wood, is considered to be one of the factors contributing to wood biomass recalcitrance for biofuel production. To better utilize wood as biofuel feedstock, it is crucial to functionally characterize all the genes involved in xylan biosynthesis during wood formation. In this report, we inves-tigated roles of poplar families GT43 and GT8 glycosyltransferases in xylan biosynthesis during wood formation. There exist seven GT43 genes in the genome of poplar (Populus trichocarpa), five of which, namely PtrGT43A, PtrGT43B,PtrGT43C, PtrGT43D, and PtrGT43E, were shown to be highly expressed in the developing wood and their encoded proteins were localized in the Golgi. Comprehensive genetic complementation coupled with chemical analyses demonstrated that overexpression of PtrGT43A/B/E but not PtrGT43C/D was able to rescue the xylan defects conferred by the Arabidopsis irx9mutant, whereas overexpression of PtrGT43C/D but not PtrGT43A/B/E led to a complementation of the xyian defects in the Arabidopsis irx14 mutant. The essential roles of poplar GT43 members in xylan biosynthesis was further substantiated by RNAi down-regulation of GT43B in the hybrid poplar (Populus alba x tremula)leading to reductions in wall thickness and xylan content in wood, and an elevation in the abundance of the xylan reducing end sequence. Wood digestibility analysis revealed that cellulase digestion released more glucose from the wood of poplar GT43B RNAi lines than the control wood, indicating a decrease in wood biomass recalcitrance. Furthermore, RNAi down-regulation of another poplar wood-associated glycosyltransferase, PoGT8D, was shown to cause decreases in wall thickness and xylan content as well as in the abundance of the xylan reducing end sequence. Together, these findings demonstrate that the poplar GT43 mem-bers form two functionally non-redundant groups, namely PtrGT43A/B/E as functional orthologs of Arabidopsis IRX9 and Ptr

  14. Hydroponic screening of poplar for trace element tolerance and accumulation.

    Science.gov (United States)

    Migeon, Aude; Richaud, Pierre; Guinet, Frédéric; Blaudez, Damien; Chalot, Michel

    2012-04-01

    Using the nutrient film technique, we screened 21 clones of poplar for growth in the presence of a mix of trace elements (TE) and for TE accumulation capacities. Poplar cuttings were exposed for four weeks to a multipollution solution consisting in 10 microM Cd, Cu, Ni, and Pb, and 200 microM Zn. Plant biomass and TE accumulation patterns in leaves varied greatly between clones. The highest Cd and Zn concentrations in leaves were detected in P. trichocarpa and P. trichocarpa hybrids, with the clone Skado (P. trichocarpa x P. maximowiczii) accumulating up to 108 mg Cd kg(-1) DW and 1510 mg Zn kg(-1) DW when exposed to a multipollution context. Our data also confirm the importance of pH and multipollution, as these factors greatly affect TE accumulation in above ground biomass. The NFT technique applied here to a large range of poplar clones also revealed the potential of the Rochester, AFO662 and AFO678 poplar clones for use in phytostabilization programs and bioenergy production, where production of less contaminated above ground biomass is suitable.

  15. The Globe laid bare

    CERN Multimedia

    Anaïs Schaeffer

    2015-01-01

    If you’re at CERN at the moment, you will certainly have noticed the work under way on the Globe. The structure, which has been in pride of place opposite the Laboratory for over ten years, has never been so completely laid bare. But, as we explained in a previous article (see here), it is all for a good cause. The Globe is built entirely from wood and certain parts of it need to be replaced.   The Globe after the removal of all the sun baffles. Image: Lucien Fortunati. Picture the general structure of the Globe. In simple terms, the building consists of two spheres, one inside the other. The inner sphere houses the Universe of Particles exhibition and the conference room and is connected to the outer sphere by two access ramps. “Each of these two spheres is made up of eighteen large supporting arcs,” explains Amaya Martínez García of the GS department, who is supervising the Globe renovation project. “These eighteen arcs are ...

  16. Control tactics of poplar diseases in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the present studies and literatures about the poplar diseases in China, the present study situation of poplar disease was introduced in this paper. 31 kinds of poplar diseases were collected of which there were 14 kinds of leaves disease, 11 kinds of branch disease, 4 kinds of root disease, 2 kinds of stand rot. Each poplar species was studied on the harm, distribution, symptom, pathogens, occurrence regulation and control measures. According to previously studies, the sustained control tactics of poplar disease were summarized in this paper.

  17. Solid Bare Strange Quark Stars

    CERN Document Server

    Xu, R X

    2003-01-01

    The reason, we need three terms of `strange', `bare', and `solid' before quark stars, is presented concisely though some fundamental issues are not certain. Observations favoring these stars are introduced.

  18. Progress and Strategies in Cross Breeding of Poplars in China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The advance in intrasection and intersection cross breeding of poplars in China over the past 50 years is reviewed. Great progress has been made in Sections Leuce and Aigeiros, and satisfactory results of intersection hybridization have been achieved in the crossing between Sections Tacamahaca and Aigeiros. The modes of hybridization include single cross, double cross, triple cross, backcross, etc. It is known that using hybrids as parents to cross with other species or hybrids is an effective and easy way to obtain heterosis. Fast growth, cold and drought tolerance, pest and disease resistance, narrow crowns and rootage, etc. are breeding goals. The conventional artificial crossing is still a major breeding method, and a combination of the conventional artificial crossing with physical radiation and chemical induction can create new triploid individuals that possess higher yield potential. The super clones cultivated have already displayed enormous socioeconomic and ecological benefits in practice. Finally, the problems that investigators have to face at present are discussed as well as some strategies in poplar cross breeding in China.

  19. Repeated unidirectional introgression towards Populus balsamifera in contact zones of exotic and native poplars

    NARCIS (Netherlands)

    Thompson, S.L.; Lamothe, M.; Meirmans, P.G.; Périnet, P.; Isabel, N.

    2010-01-01

    As the evolutionary significance of hybridization is largely dictated by its extent beyond the first generation, we broadly surveyed patterns of introgression across a sympatric zone of two native poplars (Populus balsamifera, Populus deltoides) in Quebec, Canada within which European exotic Populus

  20. Effects of irrigating poplar energy crops with landfill leachate on soil micro- and meso-fauna

    Science.gov (United States)

    Jill A. Zalesny; David R. Coyle; Ronald S. Jr. Zalesny; Adam H. Wiese

    2009-01-01

    Increased municipal solid waste generated worldwide combined with substantial demand for renewable energy has prompted testing and deployment of woody feedstock production systems that reuse and recycle wastewaters as irrigation and fertilization for the trees. Populus species and hybrids (i.e., poplars) are ideal for such systems given their fast...

  1. An efficient Agrobacterium-mediated transformation system for poplar.

    Science.gov (United States)

    Movahedi, Ali; Zhang, Jiaxin; Amirian, Rasoul; Zhuge, Qiang

    2014-06-13

    Poplar is a model system for the regeneration and genetic transformation of woody plants. To shorten the time required for studies of transgenic poplar, efforts have been made to optimize transformation methods that use Agrobacterium tumefaciens. In this study, an Agrobacterium infective suspension was treated at 4 °C for at least 10 h before infecting explants. By transforming the Populus hybrid clone "Nanlin895" (Populus deltoides×P. euramericana) with Agrobacterium harboring the PBI121:CarNAC6 binary vector, we showed that the transformation efficiency was improved significantly by multiple independent factors, including an Agrobacterium infective suspension with an OD600 of 0.7, an Agrobacterium infection for 120 min, an Agrobacterium infective suspension at a pH of 5.0, an acetosyringone concentration of 200 µM, a cocultivation at 28 °C, a cocultivation for 72 h and a sucrose concentration of 30 g/L in the cocultivation medium. We also showed that preculture of wounded leaf explants for two days increased the regeneration rate. The integration of the desired gene into transgenic poplars was detected using selective medium containing kanamycin, followed by southern blot analysis. The expression of the transgene in the transgenic lines was confirmed by northern blot analysis.

  2. An Efficient Agrobacterium-Mediated Transformation System for Poplar

    Directory of Open Access Journals (Sweden)

    Ali Movahedi

    2014-06-01

    Full Text Available Poplar is a model system for the regeneration and genetic transformation of woody plants. To shorten the time required for studies of transgenic poplar, efforts have been made to optimize transformation methods that use Agrobacterium tumefaciens. In this study, an Agrobacterium infective suspension was treated at 4 °C for at least 10 h before infecting explants. By transforming the Populus hybrid clone “Nanlin895” (Populus deltoides × P. euramericana with Agrobacterium harboring the PBI121:CarNAC6 binary vector, we showed that the transformation efficiency was improved significantly by multiple independent factors, including an Agrobacterium infective suspension with an OD600 of 0.7, an Agrobacterium infection for 120 min, an Agrobacterium infective suspension at a pH of 5.0, an acetosyringone concentration of 200 µM, a cocultivation at 28 °C, a cocultivation for 72 h and a sucrose concentration of 30 g/L in the cocultivation medium. We also showed that preculture of wounded leaf explants for two days increased the regeneration rate. The integration of the desired gene into transgenic poplars was detected using selective medium containing kanamycin, followed by southern blot analysis. The expression of the transgene in the transgenic lines was confirmed by northern blot analysis.

  3. Acquisition of Structure and Interpretation: Cases from Mandarin Bare and Non-Bare Noun Phrases

    Science.gov (United States)

    Chang, Hsiang-Hua

    2011-01-01

    Children's production of bare nominals is universal. When acquiring languages disallowing bare nominals, children will develop from the bare to the non-bare stage. However, Mandarin nominals may appear bare or non-bare in various positions with all kinds of interpretations. This dissertation conducts two acquisition studies to examine the…

  4. Response of transgenic poplar overexpressing cytosolic glutamine synthetase to phosphinothricin.

    Science.gov (United States)

    Pascual, María Belén; Jing, Zhong Ping; Kirby, Edward G; Cánovas, Francisco M; Gallardo, Fernando

    2008-01-01

    Glutamine synthetase (GS) is the main enzyme involved in ammonia assimilation in plants and is the target of phosphinothricin (PPT), an herbicide commonly used for weed control in agriculture. As a result of the inhibition of GS, PPT also blocks photorespiration, resulting in the depletion of leaf amino acid pools leading to the plant death. Hybrid transgenic poplar (Populus tremula x P. alba INRA clone 7171-B4) overexpressing cytosolic GS is characterized by enhanced vegetative growth [Gallardo, F., Fu, J., Cantón, F.R., García-Gutiérrez, A., Cánovas, F.M., Kirby, E.G., 1999. Expression of a conifer glutamine synthetase gene in transgenic poplar. Planta 210, 19-26; Fu, J., Sampalo, R., Gallardo, F., Cánovas, F.M., Kirby, E.G., 2003. Assembly of a cytosolic pine glutamine synthetase holoenzyme in leaves of transgenic poplar leads to enhanced vegetative growth in young plants. Plant Cell Environ. 26, 411-418; Jing, Z.P., Gallardo, F., Pascual, M.B., Sampalo, R., Romero, J., Torres de Navarra, A., Cánovas, F.M., 2004. Improved growth in a field trial of transgenic hybrid poplar overexpressing glutamine synthetase. New Phytol. 164, 137-145], increased photosynthetic and photorespiratory capacities [El-Khatib, R.T., Hamerlynck, E.P., Gallardo, F., Kirby, E.G., 2004. Transgenic poplar characterized by ectopic expression of a pine cytosolic glutamine synthetase gene exhibits enhanced tolerance to water stress. Tree Physiol. 24, 729-736], enhanced tolerance to water stress (El-Khatib et al., 2004), and enhanced nitrogen use efficiency [Man, H.-M., Boriel, R., El-Khatib, R.T., Kirby, E.G., 2005. Characterization of transgenic poplar with ectopic expression of pine cytosolic glutamine synthetase under conditions of varying nitrogen availability. New Phytol. 167, 31-39]. In vitro plantlets of GS transgenic poplar exhibited enhanced resistance to PPT when compared with non-transgenic controls. After 30 days exposure to PPT at an equivalent dose of 275 g ha(-1), growth

  5. Hydrologic Evaluation of a Humid Climate Poplar Phytoremediation Barrier

    Science.gov (United States)

    Swensen, K.; Rabideau, A. J.

    2016-12-01

    The emplacement of hybrid poplar trees to function as phytoremediation barriers is an appealing and sustainable groundwater management strategy because of low maintenance costs and the potential to extract large amounts of groundwater without pumping. While the effectiveness of poplar barriers has been assessed by groundwater quality monitoring, less attention has been given to physical hydrologic evaluations needed to improve barrier designs. In this research, a five year hydrologic evaluation was conducted at a poplar phytoremediation site in western NY, with the goal of quantifying ETg (evapotranspiration from groundwater) as a measure of the barrier's effectiveness in a humid climate. To consider transpiration from both vadose zone and groundwater, the hydrologic evaluation included four components: physical ET measurements, theoretical ET calculations, analysis of diurnal groundwater table fluctuations, and vadose zone modeling. The direct measurements of ETT (total) were obtained using sap flow meters installed on multiple trees within the barrier. These data were interpreted using a regression model that included theoretical ET calculations and site-specific measurements of weather parameters and poplar trunk area. Application of this model was challenged by the spatial variation in rooting depth as determined by tree excavations. To further quantify the removal of groundwater by the phytobarrier (ETg), the White Method was applied to interpret diurnal groundwater fluctuations from monitoring wells located within the barrier, in conjunction with a variably saturated-saturated flow model configured to confirm water extraction from ETg. Taken together, the results of this five year hydrologic evaluation highlight the complexity in quantifying humid climate groundwater extraction, as a large number of variables were found to influence these rates. Improved understanding of these controls will contribute to improved barrier designs that maximize ETg.

  6. Analysis of 4,664 high-quality sequence-finished poplar full-length

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, S. [University of British Columbia, Vancouver; Gunter, Lee E [ORNL; Tuskan, Gerald A [ORNL; Douglas, Carl [University of British Columbia, Vancouver; Holt, Robert A. [Genome Sciences Centre, Vancouver, BC, Canada; Jones, Steven [Genome Sciences Centre, Vancouver, BC, Canada; Marra, Marco [Genome Sciences Centre, Vancouver, BC, Canada; Bohlmann, J. [University of British Columbia, Vancouver

    2008-01-01

    The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL)-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa x P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones for genes that were differentially expressed in

  7. The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Seol Ah, E-mail: s6022029@korea.ac.kr; Choi, Young-Im, E-mail: yichoi99@forest.go.kr; Cho, Jin-Seong, E-mail: jinsung3932@gmail.com; Lee, Hyoshin, E-mail: hslee@forest.go.kr

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. - Highlights: • We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa). • We examine effects of overexpression of PagBEE3L on growth in poplar. • We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants. • BEE3L protein plays an important role in the development of plant stem.

  8. Poplar MYB115 and MYB134 Transcription Factors Regulate Proanthocyanidin Synthesis and Structure.

    Science.gov (United States)

    James, Amy Midori; Ma, Dawei; Mellway, Robin; Gesell, Andreas; Yoshida, Kazuko; Walker, Vincent; Tran, Lan; Stewart, Don; Reichelt, Michael; Suvanto, Jussi; Salminen, Juha-Pekka; Gershenzon, Jonathan; Séguin, Armand; Constabel, C Peter

    2017-05-01

    The accumulation of proanthocyanidins is regulated by a complex of transcription factors composed of R2R3 MYB, basic helix-loop-helix, and WD40 proteins that activate the promoters of biosynthetic genes. In poplar (genus Populus), MYB134 is known to regulate proanthocyanidin biosynthesis by activating key flavonoid genes. Here, we characterize a second MYB regulator of proanthocyanidins, MYB115. Transgenic poplar overexpressing MYB115 showed a high-proanthocyanidin phenotype and reduced salicinoid accumulation, similar to the effects of MYB134 overexpression. Transcriptomic analysis of MYB115- and MYB134-overexpressing poplar plants identified a set of common up-regulated genes encoding proanthocyanidin biosynthetic enzymes and several novel uncharacterized MYB transcriptional repressors. Transient expression experiments demonstrated the capacity of both MYB134 and MYB115 to activate flavonoid promoters, but only in the presence of a basic helix-loop-helix cofactor. Yeast two-hybrid experiments confirmed the direct interaction of these transcription factors. The unexpected identification of dihydromyricetin in leaf extracts of both MYB115- and MYB134-overexpressing poplar led to the discovery of enhanced flavonoid B-ring hydroxylation and an increased proportion of prodelphinidins in proanthocyanidin of the transgenics. The dramatic hydroxylation phenotype of MYB115 overexpressors is likely due to the up-regulation of both flavonoid 3',5'-hydroxylases and cytochrome b5 Overall, this work provides new insight into the complexity of the gene regulatory network for proanthocyanidin synthesis in poplar. © 2017 American Society of Plant Biologists. All Rights Reserved.

  9. Chloroplast parameters differ in wild type and transgenic poplars overexpressing gsh1 in the cytosol.

    Science.gov (United States)

    Ivanova, L A; Ronzhina, D A; Ivanov, L A; Stroukova, L V; Peuke, A D; Rennenberg, H

    2009-07-01

    Poplar mutants overexpressing the bacterial genes gsh1 or gsh2 encoding the enzymes of glutathione biosynthesis are among the best-characterised transgenic plants. However, this characterisation originates exclusively from laboratory studies, and the performance of these mutants under field conditions is largely unknown. Here, we report a field experiment in which the wild-type poplar hybrid Populus tremula x P. alba and a transgenic line overexpressing the bacterial gene gsh1 encoding gamma-glutamylcysteine synthetase in the cytosol were grown for 3 years at a relatively clean (control) field site and a field site contaminated with heavy metals. Aboveground biomass accumulation was slightly smaller in transgenic compared to wild-type plants; soil contamination significantly decreased biomass accumulation in both wild-type and transgenic plants by more than 40%. Chloroplasts parameters, i.e., maximal diameter, projection area and perimeter, surface area and volume, surface/volume ratio and a two-dimensional form coefficient, were found to depend on plant type, leaf tissue and soil contamination. The greatest differences between wild and transgenic poplars were observed at the control site. Under these conditions, chloroplast sizes in palisade tissue of transgenic poplar significantly exceeded those of the wild type. In contrast to the wild type, palisade chloroplast volume exceeded that of spongy chloroplasts in transgenic poplars at both field sites. Chlorophyll content per chloroplast was the same in wild and transgenic poplars. Apparently, the increase in chloroplast volume was not connected to changes in the photosynthetic centres. Chloroplasts of transgenic poplar at the control site were more elongated in palisade cells and close to spherical in spongy mesophyll chloroplasts. At the contaminated site, palisade and spongy cell chloroplasts of leaves from transgenic trees and the wild type were the same shape. Transgenic poplars also had a smaller chloroplast

  10. Effect of technological parameters and wood properties on cutting power in plane milling of juvenile poplar wood

    Directory of Open Access Journals (Sweden)

    Barcík Štefan

    2008-10-01

    Full Text Available This paper presents the results of experimental measurements aimed at observing the effect of technological parameters (cutting speed vc and feed speed vf , type of wood (juvenile wood and mature wood andwood species (aspen Populus tremula, L. and hybrid poplar Populus x Euramericana „Serotina“ on cutting power during plane milling of poplar wood. The results showed the reduction of cutting power with the decrease of cutting speed and feed speed. Lower cutting power was also measured in milling hybrid poplar than in milling aspen. The test also confirmed the effect of different anatomical and chemical structure of juvenile wood in relation to mature wood on different physical and mechanical properties of such wood and hence also on the cutting power in processing juvenile wood.

  11. Stomatal factors and vulnerability of stem xylem to cavitation in poplars.

    Science.gov (United States)

    Arango-Velez, Adriana; Zwiazek, Janusz J; Thomas, Barb R; Tyree, Melvin T

    2011-10-01

    The relationships between the vulnerability of stem xylem to cavitation, stomatal conductance, stomatal density, and leaf and stem water potential were examined in six hybrid poplar (P38P38, Walker, Okanese, Northwest, Assiniboine and Berlin) and balsam poplar (Populus balsamifera) clones. Stem xylem cavitation resistance was examined with the Cavitron technique in well-watered plants grown in the greenhouse. To investigate stomatal responses to drought, plants were subjected to drought stress by withholding watering for 5 (mild drought) and 7 (severe drought) days and to stress recovery by rewatering severely stressed plants for 30 min and 2 days. The clones varied in stomatal sensitivity to drought and vulnerability to stem xylem cavitation. P38P38 reduced stomatal conductance in response to mild stress while the balsam poplar clone maintained high leaf stomatal conductance under more severe drought stress conditions. Differences between the severely stressed clones were also observed in leaf water potentials with no or relatively small decreases in Assiniboine, P38P38, Okanese and Walker. Vulnerability to drought-induced stem xylem embolism revealed that balsam poplar and Northwest clones reached loss of conductivity at lower stem water potentials compared with the remaining clones. There was a strong link between stem xylem resistance to cavitation and stomatal responsiveness to drought stress in balsam poplar and P38P38. However, the differences in stomatal responsiveness to mild drought suggest that other drought-resistant strategies may also play a key role in some clones of poplars exposed to drought stress. Copyright © Physiologia Plantarum 2011.

  12. Impact of RAV1-engineering on poplar biomass production: a short-rotation coppice field trial.

    Science.gov (United States)

    Moreno-Cortés, Alicia; Ramos-Sánchez, José Manuel; Hernández-Verdeja, Tamara; González-Melendi, Pablo; Alves, Ana; Simões, Rita; Rodrigues, José Carlos; Guijarro, Mercedes; Canellas, Isabel; Sixto, Hortensia; Allona, Isabel

    2017-01-01

    Early branching or syllepsis has been positively correlated with high biomass yields in short-rotation coppice (SRC) poplar plantations, which could represent an important lignocellulosic feedstock for the production of second-generation bioenergy. In prior work, we generated hybrid poplars overexpressing the chestnut gene RELATED TO ABI3/VP1 1 (CsRAV1), which featured c. 80% more sylleptic branches than non-modified trees in growth chambers. Given the high plasticity of syllepsis, we established a field trial to monitor the performance of these trees under outdoor conditions and a SRC management. We examined two CsRAV1-overexpression poplar events for their ability to maintain syllepsis and their potential to enhance biomass production. Two poplar events with reduced expression of the CsRAV1 homologous poplar genes PtaRAV1 and PtaRAV2 were also included in the trial. Under our culture conditions, CsRAV1-overexpression poplars continued developing syllepsis over two cultivation cycles. Biomass production increased on completion of the first cycle for one of the overexpression events, showing unaltered structural, chemical, or combustion wood properties. On completion of the second cycle, aerial growth and biomass yields of both overexpression events were reduced as compared to the control. These findings support the potential application of CsRAV1-overexpression to increase syllepsis in commercial elite trees without changing their wood quality. However, the syllepsis triggered by the introduction of this genetic modification appeared not to be sufficient to sustain and enhance biomass production.

  13. Identification of CpTI Gene Integration for 2-year-old Transgenic Poplars at DNA Level

    Institute of Scientific and Technical Information of China (English)

    Zhang Qian; Lin Shanzhi; Lin Yuanzhen; Zhang Zhiyi; Liu Haijun; Zou Yening; Wang Zeliang

    2004-01-01

    The putative transgenic hybrid triploid poplars [(P. Tomentosa × P. Bolleana) × P. Tomentosa] with CpTI gene have been outplanted in test field for 2 years. Although the authors' previous studies have proved that they are highly resistant to 3 species of poplar-threatening insect pests and contain high content of CpTI protein in foliage, incorporation status of foreign CpTI gene in poplar genome is uncertain. In this present study, the incorporation of foreign CpTI gene in genome of 5 transgenic poplars was confirmed by PCR and Southern blotting analysis. DNA amplification showed that there were clear DNA bands of about 450bp specific to CpTI gene in transgenic lanes, while no corresponding band in non-transgenic lane was observed. Correspondingly, clear DNA hybridization signals and no signal were exhibited on film for DNA Southern blotting analysis in transgenic lanes and non-transgenic lane, respectively, which further confirmed the stable integration of foreign CpTI gene in genome of 2-year-old transgenic poplar.

  14. Continuous steam hydrolysis of tulip poplar

    Energy Technology Data Exchange (ETDEWEB)

    Fieber, C.A.; Roberts, R.S.; Faass, G.S.; Muzzy, J.D.; Colcord, A.R.; Bery, M.K.

    1982-01-01

    The continuous hydrolysis of poplar chips by steam at 300-350 psi resulted in the separation of hemicellulose (I) cellulose and lignin components. The I fraction was readily depolymerised by steam to acetic acid, furfural, methanol, and xylose.

  15. Antisense down-regulation of 4CL expression alters lignification, tree growth, and saccharification potential of field-grown poplar

    Science.gov (United States)

    Steven L. Voelker; Barbara Lachenbruch; Frederick C. Meinzer; Michael Jourdes; Chanyoung Ki; Ann M. Patten; Laurence B. Davin; Norman G. Lewis; Gerald A. Tuskan; Lee Gunter; Stephen R. Decker; Michael J. Selig; Robert Sykes; Michael E. Himmel; Peter Kitin; Olga Shevchenko; Steven H. Strauss

    2010-01-01

    Transgenic down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been reported as a means for reducing lignin content in cell walls and increasing overall growth rates, thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplar (Populus tremula...

  16. Effect of water regime on poplar cultivation

    Directory of Open Access Journals (Sweden)

    Letić Ljubomir

    2006-01-01

    Full Text Available The effect of water regime on the growth and development of plantations of hydrologically conditioned species, poplars was researched in the alluvial plain of the river Tamiš. The investigations were carried out during the period 2000-2003 on the area of FA "Opovo", KO Sakule, and the study results elucidate the very complex relationships between the hydrological conditions of the site and the growth and increment of the study poplar plantations, cl. I-214. .

  17. Study on Poplar Industrialization in Jiangsu:(3)Conclusions and Recommendations on Poplar Industrialization Management

    Institute of Scientific and Technical Information of China (English)

    SHEN Wenxing; ZHOU Dingguo; XU Xinping

    2006-01-01

    This article concludes that the creation of a new industrial management,including the innovation of management institution,operation system,industrial policies and industrial technology,is a solution to the management optimization of the poplar industry.The further development of the poplar industry is beneficial to the sustainable development of the society,economy and ecological environment in Jiangsu province.

  18. Nucleotide diversity among natural populations of a North American poplar (Populus balsamifera, Salicaceae).

    Science.gov (United States)

    Breen, Amy L; Glenn, Elise; Yeager, Adam; Olson, Matthew S

    2009-01-01

    Poplars (Populus spp.) comprise an important component of circumpolar boreal forest ecosystems and are the model species for tree genomics. In this study, we surveyed genetic variation and population differentiation in three nuclear genes among populations of balsam poplar (Populus balsamifera) in North America. We examined nucleotide sequence variation in alcohol dehydrogenase 1 (Adh1) and glyceraldehyde 3-phosphate dehydrogenase (G3pdh), two well-studied nuclear loci in plants, and abscisic acid insensitivity 1B (ABI1B), a locus coincident with timing of seasonal dormancy in quantitative trait locus (QTL) studies of hybrid poplars. We compared estimates of baseline population genetic parameters for these loci with those obtained in studies of other poplar species, particularly European aspen (Populus tremula). Average pairwise nucleotide diversity (pi(tot) = 0.00216-0.00353) was equivalent to that in Populus trichocarpa, but markedly less than that in P. tremula. Elevated levels of population structure were observed in ABI1B between the northern and southern regions (F(CT) = 0.184, P boreal plant species.

  19. Evaluation of safety and efficacy of NexGen – an ultrathin strut and hybrid cell design cobalt-chromium bare metal stent implanted in a real life patient population – the Polish NexGen Registry

    Directory of Open Access Journals (Sweden)

    Krzysztof Milewski

    2016-08-01

    Full Text Available Introduction : Despite the dominance of drug-eluting stents in modern interventional cardiology, there is still a niche for bare metal stents. Aim: The aim of the Polish NexGen registry was to evaluate the safety and efficacy of a new generation cobalt-chromium NexGen stent in a real life patient population. Material and methods : A prospective multi-center registry was conducted in five clinical sites of American Heart of Poland. Three hundred and eighty-three patients who underwent percutaneous coronary intervention (PCI with NexGen stent implantation were included. Clinical follow-up was performed at 1, 6 and 12 months. Additionally, a group of 42 randomly selected patients underwent control angiography at 6 months (10.96% of study population. The primary endpoint was occurrence of target vessel revascularization (TVR at 6-month follow-up. Angiographic endpoints included rates of binary restenosis and late lumen loss at 6-month follow-up based on QCA analysis. Multivessel disease was present in more than 70% of patients, and 52.4% of lesions were complex. The main indications for angiography were non-ST elevation acute coronary syndromes (54.8% and ST elevation myocardial infarction (34.99%. Results : At 6-month follow-up 47 (12.7% patients reached the primary endpoint of TVR. The composite of major acute cardiac event rates at 30-day and 6- and 12-month follow-up was 6.01% (n = 23, 18.5% (n = 69 and 25.21% (n = 92 respectively. Control angiography performed after 6 months showed in-stent late loss of 0.66 ±0.71 mm and a binary restenosis rate of 16.7%. Conclusions : Our study showed that PCI with the NexGen stent is safe and effective at 6- and 12-month follow-up. Angiographic results showed a satisfactory restenosis rate and low late lumen loss.

  20. Forest biorefinery: Potential of poplar phytochemicals as value-added co-products.

    Science.gov (United States)

    Devappa, Rakshit K; Rakshit, Sudip K; Dekker, Robert F H

    2015-11-01

    The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  1. Degradation of poplar bark by Panaeolus

    Energy Technology Data Exchange (ETDEWEB)

    Scurti, J.C.; Fiussello, N.; Gullino, M.L.; Ferrara, R.

    1978-01-01

    Pure cultures of 41 strains of Paneolus were tested for their ability to break down poplar bark with a view to their possible use for biodegradation of this waste product of paper manufacture. Most strains were able to grow (slowly) on sterilized poplar bark and showed high ligninolytic activity. Some strains also showed cellulolytic action. Almost all the strains showed phenol-oxidase activity, but there was no correlation between lignin decomposition and phenol-oxidase activity. The amounts of bark degraded by the fungi were relatively small (3.2 - 13.0% loss of dry weight after six months incubation).

  2. Matrix methods for bare resonator eigenvalue analysis.

    Science.gov (United States)

    Latham, W P; Dente, G C

    1980-05-15

    Bare resonator eigenvalues have traditionally been calculated using Fox and Li iterative techniques or the Prony method presented by Siegman and Miller. A theoretical framework for bare resonator eigenvalue analysis is presented. Several new methods are given and compared with the Prony method.

  3. Bare strange quark stars formation and emission

    CERN Document Server

    Xu, R X

    2002-01-01

    Recent achievements of bare strange stars are briefly reviewed. A nascent protostrange star should be bare because of strong mass ejection and high temperature after the supernova detonation flame, and a crust can also hardly form except for a super-Eddington accretion. The magnetosphere of a bare strange star is composed mainly of electron-positron pair plasma, where both inner and outer vacuum gaps work for radio as well as high energy nonthermal emission. A featureless thermal spectrum is expected since no ion is above the quark surface, whilst electron cyclotron lines could appear in some bare strange stars with suitable magnetic fields. Various astrophysical implications of bare strange stars are discussed.

  4. Mammalian cytochrome CYP2E1 triggered differential gene regulation in response to trichloroethylene (TCE) in a transgenic poplar.

    Science.gov (United States)

    Kang, Jun Won; Wilkerson, Hui-Wen; Farin, Federico M; Bammler, Theo K; Beyer, Richard P; Strand, Stuart E; Doty, Sharon L

    2010-08-01

    Trichloroethylene (TCE) is an important environmental contaminant of soil, groundwater, and air. Studies of the metabolism of TCE by poplar trees suggest that cytochrome P450 enzymes are involved. Using poplar genome microarrays, we report a number of putative genes that are differentially expressed in response to TCE. In a previous study, transgenic hybrid poplar plants expressing mammalian cytochrome P450 2E1 (CYP2E1) had increased metabolism of TCE. In the vector control plants for this construct, 24 h following TCE exposure, 517 genes were upregulated and 650 genes were downregulated over 2-fold when compared with the non-exposed vector control plants. However, in the transgenic CYP2E1 plant, line 78, 1,601 genes were upregulated and 1,705 genes were downregulated over 2-fold when compared with the non-exposed transgenic CYP2E1 plant. It appeared that the CYP2E1 transgenic hybrid poplar plants overexpressing mammalian CYP2E1 showed a larger number of differentially expressed transcripts, suggesting a metabolic pathway for TCE to metabolites had been initiated by activity of CYP2E1 on TCE. These results suggest that either the over-expression of the CYP2E1 gene or the abundance of TCE metabolites from CYP450 2E1 activity triggered a strong genetic response to TCE. Particularly, cytochrome p450s, glutathione S-transferases, glucosyltransferases, and ABC transporters in the CYP2E1 transgenic hybrid poplar plants were highly expressed compared with in vector controls.

  5. The Populus superoxide dismutase gene family and its responses to drought stress in transgenic poplar overexpressing a pine cytosolic glutamine synthetase (GS1a.

    Directory of Open Access Journals (Sweden)

    Juan Jesús Molina-Rueda

    Full Text Available BACKGROUND: Glutamine synthetase (GS plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4 expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during drought, members of the superoxide dismutase (SOD family were reciprocally regulated in GS poplar when compared with the wild-type control, in all tissues examined. SOD was the only gene family found to exhibit such patterns. RESULTS: In silico analysis of the Populus genome identified 12 SOD genes and two genes encoding copper chaperones for SOD (CCSs. The poplar SODs form three phylogenetic clusters in accordance with their distinct metal co-factor requirements and gene structure. Nearly all poplar SODs and CCSs are present in duplicate derived from whole genome duplication, in sharp contrast to their predominantly single-copy Arabidopsis orthologs. Drought stress triggered plant-wide down-regulation of the plastidic copper SODs (CSDs, with concomitant up-regulation of plastidic iron SODs (FSDs in GS poplar relative to the wild type; this was confirmed at the activity level. We also found evidence for coordinated down-regulation of other copper proteins, including plastidic CCSs and polyphenol oxidases, in GS poplar under drought conditions. CONCLUSIONS: Both gene duplication and expression divergence have contributed to the expansion and transcriptional diversity of the Populus SOD/CCS families. Coordinated down-regulation of major copper proteins in drought-tolerant GS poplars supports the copper cofactor economy model where copper supply is preferentially allocated for plastocyanins to sustain photosynthesis during drought. Our results also extend previous findings on the compensatory regulation between chloroplastic CSDs and FSDs, and suggest that this

  6. Diversity of arthropod community in transgenic poplar-cotton ecosystems.

    Science.gov (United States)

    Zhang, D J; Lu, Z Y; Liu, J X; Li, C L; Yang, M S

    2015-12-02

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of plain cotton fields in China. Here, we performed a systematic survey of the diversity and population of arthropod communities in four different combination of poplar-cotton eco-systems, including I) non-transgenic poplar and non-transgenic cotton fields; II) non-transgenic poplar and transgenic cotton fields [Bacillus thuringiensis (Bt) cotton]; III) Bt transgenic poplar (high insect resistant strain Pb29) and non-transgenic cotton; and IV) transgenic poplar and transgenic cotton fields, over a period of 3 years. Based on the statistical methods used to investigate community ecology, the effects of transgenic ecosystems on the whole structure of the arthropod community, on the structure of arthropods in the nutritive layer, and on the similarity of arthropod communities were evaluated. The main results were as follows: the transgenic poplar-cotton ecosystem has a stronger inhibitory effect on insect pests and has no impact on the structure of the arthropod community, and therefore, maintains the diversity of the arthropod community. The character index of the community indicated that the structure of the arthropod community of the transgenic poplar-cotton ecosystem was better than that of the poplar-cotton ecosystem, and that system IV had the best structure. As for the abundance of nutritional classes, the transgenic poplar-cotton ecosystem was also better than that of the non-transgenic poplar-cotton ecosystem. The cluster analysis and similarity of arthropod communities between the four different transgenic poplar-cotton ecosystems illustrated that the structure of the arthropod community excelled in the small sample of the transgenic poplar-cotton ecosystems.

  7. 采用一种混合骨干微粒群优化算法的感应电机转子断条故障诊断%Broken Rotor Bar Fault Diagnosis of Induction Motors Using a Hybrid Bare-bones Particle Swarm Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    王攀攀; 史丽萍; 张勇; 韩丽

    2012-01-01

    在传统定子电流频谱分析中,感应电机转子断条故障特征经常被基波分量淹没而无法准确检测.针对该问题,提出一种基于混合骨干微粒群优化算法的转子断条故障诊断新方法.该方法首先根据电流信号与单位余弦基函数的内积最大准则,利用混合骨干微粒群算法强大的全局搜索能力,准确估计出基波波形参数;然后利用波形参数构造出基波表达式,并将其从原电流信号中剔除,达到突出故障特征的目的.针对微粒群算法在进化后期收敛缓慢的缺点,通过K-均值聚类方式,引入单纯形法对其进行改进,使整个算法的广度探索与深度开发能力得到了有效均衡.最后,对模拟数据和实测信号进行实验,结果验证了所提方法的有效性和优越性.%In the traditional motor current signature spectrum analysis, the characteristic components of broken rotor bar fault are often submerged by the fundamental component. In order to overcome this shortcoming, a novel method for fault diagnosis was proposed based on a hybrid bare-bones particle swarm optimization algorithm. According to the maximum inner product between the stator current signature and cosine basis functions, the method could estimate precisely the waveform parameters of the fundamental component by using the powerful global search capability of the hybrid optimization algorithm. Using these waveform parameters, the expression of the fundamental component was constructed to eliminate the fundamental component from the stator current signature and to highlight the fault characteristic components. For the slow convergence rate at the late evolution process of particle swarm optimization, the simplex method was introduced into the bare-bones particle swarm optimization by using a new hybrid strategy based on the K-means clustering. This made the hybrid optimization algorithm achieve a nice balance of exploitation and exploration capability. Finally

  8. Mycorrhizal formation of nine ectomycorrhizal fungi on poplar cuttings

    Institute of Scientific and Technical Information of China (English)

    Lei MA; Xiaoqin WU; Ling ZHENG

    2008-01-01

    In order to discover which ectomycorrhizal-(ECM) fungi have better growth-promoting effects on poplars, cuttings from four poplar species were inoculated with nine species of ECM fungi by three methods. We investigated the status of mycorrhizal formation and the effects of these fungi on the growth of the poplars. The results show that Xrocomus chrysentero (Xc), Boletus edu-lis (Be), Pisolithus tinctorius (Pt) and Laccaria amethystea (La) formed clear ectomycorrhizal symbiosis with the poplar seedlings. Among these four ECM fungi, Xc had the greatest ability to develop mycorrhizae with all four poplar species. Be shows a greater ability to form mycor-rhizae with Populus deltoides Bartr cv. 'Lux' (Poplar I-69). Pt and La had relatively weaker abilities of colonization. The other five ECM fungal species, i.e., Scleroderma luteus (S1), Leeeinum scabrum (Ls), Boletus speeiosus (Bs), Calvatia eraniiformis (Cc) and Rhizopogen luteous (RI) could not easily form mycorrhizae with poplar seed-lings grown in sterilized substrates, but could do so in non-sterilized soil. With the method of drilling and inject-ing liquid inoculum, a simple operation, the mycorrhizal infection rates were higher than with the other two meth-ods, applying solid inoculum as fertilizer at the bottom of the pots and dipping roots in the inoculum slurry. P. simonii Carr. formed mycorrhizae with most of the nine ECM fungi. P. × euramericana (Dode) Guinier cv. 'San Martino' (Poplar 1-72) and P. deltoids Harvard × P. del-toids Lux (Poplar NL-351) had the highest compatibility with Pt. Poplar I-69 shows the highest compatibility with Xc. The study indicates that the optimal ECM fungi for poplars I-69, I-72 and NL-351 were Be, Xc and Pt, respectively. The optimal fungi for P. simonii Carr. were Xc and Be. These ECM fungi promoted the growth of the poplar seedlings significantly.

  9. Genetics Home Reference: bare lymphocyte syndrome type I

    Science.gov (United States)

    ... Home Health Conditions bare lymphocyte syndrome type I bare lymphocyte syndrome type I Enable Javascript to view ... boxes. Download PDF Open All Close All Description Bare lymphocyte syndrome type I (BLS I) is an ...

  10. ADVANCING PROTOCOLS FOR POPLARS in vitro PROPAGATION, REGENERATION AND SELECTION OF TRANSFORMANTS

    Directory of Open Access Journals (Sweden)

    Nataliia Kutsokon

    2013-02-01

    Full Text Available Poplars (genus Populus have emerged as a model organism for forest biotechnology, and genetic modification is more advanced for this genus than for any other tree. So far several protocols for microclonal propagation and regeneration for Populus species have been developed. However it is well known that these protocols differ for various species and need to be adapted even for different clones of the same species. This work was focused on developing of protocols for propagation, regeneration and putative transformant´s selection of aspen Populus tremula L. and other two fast-growing Populus species (P. nigra L., P. x canadensis Moench. The regeneration ability for black poplar explants was demonstrated to be three times higher compared to those for aspen and hybrid poplar. It was found that concentration 1 mg/L of phosphinothricin and 25 mg/L of kanamycin is toxic for non- transgenic plant tissues of P. x canadensis and can be applied in transformation experiments when genes of resistance to the corresponding selective agents into the plant genome are introduced.

  11. Study on Poplar Industrialization in Jiangsu: (2) Present Status and Problems of Poplar Industrialization

    Institute of Scientific and Technical Information of China (English)

    SHEN Wenxing; ZHOU Dingguo; XU Xinping

    2006-01-01

    This paper lists the existing main problems that poplar industry faces in Jiangsu and analyses the causes and the activities of different industry related to management institution and system according to the factors of knowledge infrastructure, institutional setups, government policies and production structure.

  12. Bare-Bones Teaching-Learning-Based Optimization

    Directory of Open Access Journals (Sweden)

    Feng Zou

    2014-01-01

    Full Text Available Teaching-learning-based optimization (TLBO algorithm which simulates the teaching-learning process of the class room is one of the recently proposed swarm intelligent (SI algorithms. In this paper, a new TLBO variant called bare-bones teaching-learning-based optimization (BBTLBO is presented to solve the global optimization problems. In this method, each learner of teacher phase employs an interactive learning strategy, which is the hybridization of the learning strategy of teacher phase in the standard TLBO and Gaussian sampling learning based on neighborhood search, and each learner of learner phase employs the learning strategy of learner phase in the standard TLBO or the new neighborhood search strategy. To verify the performance of our approaches, 20 benchmark functions and two real-world problems are utilized. Conducted experiments can been observed that the BBTLBO performs significantly better than, or at least comparable to, TLBO and some existing bare-bones algorithms. The results indicate that the proposed algorithm is competitive to some other optimization algorithms.

  13. High-performance, bare silver nanowire network transparent heaters.

    Science.gov (United States)

    Ergun, Orcun; Coskun, Sahin; Yusufoglu, Yusuf; Unalan, Husnu Emrah

    2016-11-04

    Silver nanowire (Ag NW) networks are one of the most promising candidates for the replacement of indium tin oxide (ITO) thin films in many different applications. Recently, Ag-NW-based transparent heaters (THs) showed excellent heating performance. In order to overcome the instability issues of Ag NW networks, researchers have offered different hybrid structures. However, these approaches not only require extra processing, but also decrease the optical performance of Ag NW networks. So, it is important to investigate and determine the thermal performance limits of bare-Ag-NW-network-based THs. Herein, we report on the effect of NW density, contact geometry, applied bias, flexing and incremental bias application on the TH performance of Ag NW networks. Ag-NW-network-based THs with a sheet resistance and percentage transmittance of 4.3 Ω sq(-1) and 83.3%, respectively, and a NW density of 1.6 NW μm(-2) reached a maximum temperature of 275 °C under incremental bias application (5 V maximum). With this performance, our results provide a different perspective on bare-Ag-NW-network-based transparent heaters.

  14. Interaction of Hg Atom with Bare Si(111) Surface

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-Jun; LIU Ying

    2006-01-01

    To evaluate the interaction between Hg atom and bare Si(111) surface, three types of silicon cluster models of Si4H7, Si7H10 and Si16H20 together with their Hg complexes were studied by using hybrid (U)B3LYP density functional theory method. Optimized geometries and energies for Hg atom on different adsorption sites indicate that: 1) the binding energies at different adsorption sites are small (ranging from ~3 to 8 kJ/mol dependent on the adsorption sites), suggesting a weak interaction between Hg atom and silicon surface; 2) the most favorable adsorption site is the on top (T) site. By analyzing their natural bonding orbitals, the possible reason of this difference is suggested.

  15. Genetic Modification of Short Rotation Poplar Biomass Feedstock for Efficient Conversion to Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Dinus, R.J.

    2000-08-30

    The Bioenergy Feedstock Development Program, Environmental Sciences Division, Oak Ridge National Laboratory is developing poplars (Populus species and hybrids) as sources of renewable energy, i.e., ethanol. Notable increases in adaptability, volume productivity, and pest/stress resistance have been achieved via classical selection and breeding and intensified cultural practices. Significant advances have also been made in the efficiencies of harvesting and handling systems. Given these and anticipated accomplishments, program leaders are considering shifting some attention to genetically modifying feedstock physical and chemical properties, so as to improve the efficiency with which feedstocks can be converted to ethanol. This report provides an in-depth review and synthesis of opportunities for and feasibilities of genetically modifying feedstock qualities via classical selection and breeding, marker-aided selection and breeding, and genetic transformation. Information was collected by analysis of the literature, with emphasis on that published since 1995, and interviews with prominent scientists, breeders, and growers. Poplar research is well advanced, and literature is abundant. The report therefore primarily reflects advances in poplars, but data from other species, particularly other shortrotation hardwoods, are incorporated to fill gaps. An executive summary and recommendations for research, development, and technology transfer are provided immediately after the table of contents. The first major section of the report describes processes most likely to be used for conversion of poplar biomass to ethanol, the various physical and chemical properties of poplar feedstocks, and how such properties are expected to affect process efficiency. The need is stressed for improved understanding of the impact of change on both overall process and individual process step efficiencies. The second part documents advances in trait measurement instrumentation and methodology

  16. Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

    Science.gov (United States)

    Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

    2016-10-01

    The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality.

  17. Electron beam control for barely separated beams

    Science.gov (United States)

    Douglas, David R.; Ament, Lucas J. P.

    2017-04-18

    A method for achieving independent control of multiple beams in close proximity to one another, such as in a multi-pass accelerator where coaxial beams are at different energies, but moving on a common axis, and need to be split into spatially separated beams for efficient recirculation transport. The method for independent control includes placing a magnet arrangement in the path of the barely separated beams with the magnet arrangement including at least two multipole magnets spaced closely together and having a multipole distribution including at least one odd multipole and one even multipole. The magnetic fields are then tuned to cancel out for a first of the barely separated beams to allow independent control of the second beam with common magnets. The magnetic fields may be tuned to cancel out either the dipole component or tuned to cancel out the quadrupole component in order to independently control the separate beams.

  18. Hvorfor siger vi ikke bare ugh?!

    DEFF Research Database (Denmark)

    Pálfi, Loránd-Levente

    2009-01-01

    Det danske sprog er ramt af en flerdobbelt katastrofe: De unge i folkeskolerne og gymnasierne taler og skriver et stadigt dårligere dansk, og forskningen i dansk sprog går i stå. Og Dansk Sprognævn, som burde stå vagt om sproget, lader ikke bare stå til, men ophæver forfaldet til lov. Er en "B-fi...

  19. Fishbone Instability Excited by Barely Trapped Electrons

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-Tian; LONG Yong-Xing; DONG Jia-Qi; WANG Long; Fulvio Zonca

    2006-01-01

    Fishbone instability excited by barely trapped suprathermal electrons (BTSEs) in tokamaks is investigated theoretically. The frequency of the mode is found to close to procession frequency of BTSEs. The growth rate of the mode is much smaller than that of the ideal magnetohytrodynamic (MHD) internal kink mode that is in contrast to the case of trapped ion driven fishbone instability. The analyses also show that spatial density gradient reversal is necessary for the instability. The correlation of the results with experiments is discussed.

  20. Water Accommodation on Bare and Coated Ice

    Science.gov (United States)

    Kong, Xiangrui

    2015-04-01

    A good understanding of water accommodation on ice surfaces is essential for quantitatively predicting the evolution of clouds, and therefore influences the effectiveness of climate models. However, the accommodation coefficient is poorly constrained within the literature where reported values vary by up to three orders of magnitude. In addition, the complexity of the chemical composition of the atmosphere plays an important role in ice phase behavior and dynamics. We employ an environmental molecular beam (EMB) technique to investigate molecular water interactions with bare and impurity coated ice at temperatures from 170 K to 200 K. In this work, we summarize results of water accommodation experiments on bare ice (Kong et al., 2014) and on ice coated by methanol (Thomson et al., 2013), butanol (Thomson et al., 2013) and acetic acid (Papagiannakopoulos et al., 2014), and compare those results with analogous experiments using hexanol and nitric acid coatings. Hexanol is chosen as a complementary chain alcohol to methanol and butanol, while nitric acid is a common inorganic compound in the atmosphere. The results show a strong negative temperature dependence of water accommodation on bare ice, which can be quantitatively described by a precursor model. Acidic adlayers tend to enhance water uptake indicating that the system kinetics are thoroughly changed compared to bare ice. Adsorbed alcohols influence the temperature dependence of the accommodation coefficient and water molecules generally spend less time on the surfaces before desorbing, although the measured accommodation coefficients remain high and comparable to bare ice for the investigated systems. We conclude that impurities can either enhance or restrict water uptake in ways that are influenced by several factors including temperature and type of adsorbant, with potential implications for the description of ice particle growth in the atmosphere. This work was supported by the Swedish Research Council and

  1. Dinamica şi caracteristicile creşterii a şase clone de plop hibrid pe parcursul unui ciclu de producţie într-o plantație comparativă din Depresiunea Rădăuţi [The dynamics and growth characteristics of six hybrid poplar clones during a production cycle in a comparative plantation from Rădăuți Depression

    OpenAIRE

    Dănilă Iulian; Avăcăriței Daniel; Savin Alexei; Roibu Cătălin Constantin; Bouriaud Olivier; Duduman Mihai-Leonard; Bouriaud Laura

    2015-01-01

    The poplar (Populus spp.) plays an important role in worldwide forest economy, responding to the necessities of obtaining high biomass production in a short time. Short rotation forests (SRF) are developing continuously in Romania. Several studies have been undertaken to identify the clones with high productivity and suitable technologies. The aim of this study was to register the annual increments in diameter, height and volume in an experimental poplar crops with a short-term rotation of...

  2. Yield physiology of short rotation intensively cultured poplars

    Science.gov (United States)

    J. G. Isebrands; N. D. Nelson; D. I. Dickmann; D. A. Michael

    1983-01-01

    An integrated research approach is described for studying yield physiology of short rotation intensively cultured (SRIC) poplar plantations. Branch architecture differs with clone and stand density, but the clonal ranking of important branch characteristics does not change with spacing.

  3. Preliminary Functional-Structural Modeling on Poplar (Salicaceae)

    CERN Document Server

    Liu, Dongxiang; Letort, Véronique; Xing, Meijun; Gang, Yang; Huang, Xinyuan; Cao, Weiqun

    2010-01-01

    Poplar is one of the best fast-growing trees in the world, widely used for windbreak and wood product. Although architecture of poplar has direct impact on its applications, it has not been descried in previous poplar models, probably because of the difficulties raised by measurement, data processing and parameterization. In this paper, the functional-structural model GreenLab is calibrated by using poplar data of 3, 4, 5, 6 years old. The data was acquired by simplifying measurement. The architecture was also simplified by classifying the branches into several types (physiological age) using clustering analysis, which decrease the number of parameters. By multi-fitting the sampled data of each tree, the model parameters were identified and the plant architectures at different tree ages were simulated.

  4. Poplar: A Java Extension for Evolvable Component Integration

    CERN Document Server

    Nyström-Persson, Johan

    2011-01-01

    The Java programming language contains many features that aid component-based software development (CBSD), such as interfaces, visibility levels, and strong support for encapsulation. However, component evolution often causes so-called breaking changes, largely because of the rigidity of component interconnections in the form of explicit method calls and field accesses. We present a Java extension, Poplar, which we are currently developing. In Poplar, inter-component dependencies are expressed using declarative queries; concrete linking code, generated using a planning algorithm, replaces these at compile time. Poplar includes a minimal specification language based on typestate-like protocols and labels, and a lightweight effect system, which ensures the absence of unwanted interference between hand-written code and generated code. We give several examples of fully automatic component integration using Poplar, and demonstrate its potential to simplify object-oriented software development greatly through evolv...

  5. 30 CFR 57.12080 - Bare conductor guards.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work...

  6. 30 CFR 57.12012 - Bare signal wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

  7. 30 CFR 56.12012 - Bare signal wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Bare signal wires. The potential on bare signal wires accessible to contact by persons shall not exceed...

  8. Study of enhanced bare land index using Landsat ETM+ image

    Science.gov (United States)

    Dou, P.; Chen, Y.

    2016-12-01

    For most bare land index without considering the spectrum similarity between high reflectivity buildings and bare land on the ETM+ remote sensing image, this paper has proposed bareness area index(BAI) and short bareness area index(SBAI) by analysing the spectrum characteristics of high reflectivity buildings and bare land. The impact of vegetation and water body to BAI and SBAI was decreased by using SAVI(Soil Adjusted Vegetation Index) and MNDWI(Modified Normalized Difference Water Index). Based on BAI and SBAI, we also used IBI(Index-based Built-up Index) to build enhanced bare land index. Bare land differences between BAI and IBI, SBAI and IBI were stretched by using an exponential function. Imitating NDVI, EBAI(Enhanced Bareness Area Index) and ESBAI(Enhanced Short Bareness Area Index) was constructed. And finally a statistical analysis indicates that EBAI and ESBAI can make bare land positive and background object negative, and comparing most other bare land index, these tow index have higher accuracy and are more easier to find a threshold to separate bare land and other land use type while effectively suppressing noise.

  9. Field test of new poplar clone in Shangdong Province

    Institute of Scientific and Technical Information of China (English)

    QIN Guang-hua; JIANG Yue-zhong; QIAO Yu-ling; B.Nottola

    2003-01-01

    Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province. Eighteen poplar clones belonging to Populus aigeiros section were introduced from Italy, Turkey and domestic regions. Populus deltoides cv. 'Lux' I-69/55 (I-69), which was widely used in Shandong Province, China, was taken as control clone (I-69). Following a randomized complete block design, seedling test and controlled afforestation trials were carried out at Juxian County, Caoxian County and Laiyang City. The results showed that the poplar clone (Populus × euramericana cv. '102/74'), namely 102/74, performed well both in terms of adaptability and growth rate. The mean height of 13.9 m (H), diameter at breast height of 18.0 cm (DBH) and volume growth of 0.1445 m3 (V) were 2.2 %, 21.6% and 52.9 % higher than those of I-69 (CK), respectively, at the age of 5 years at three experimental sites. Moreover, the clone can be propagated easily and showed high resistance to poplar disease, pest as well as salinity and had longer growing period. Furthermore, wood basic density and fiber length of new poplar clone (102/74) were as same as I-69 (CK). It was concluded that the selected clone (102/74) was ideal for the establishment of fast-growing poplar plantations, especially for the pulpwood plantations in Shandong Province.

  10. Poplar and its bacterial endophytes: coexistence and harmony

    Energy Technology Data Exchange (ETDEWEB)

    van der Lelie, D.; Taghavi, S.; Monchy, S.; Schwender, J.; Miller, L.; Ferrieri, R.; Rogers, A.; Zhu, W.; Weyens, N.; Vangronsveld, J.; Newman, L.

    2009-09-01

    Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an improved understanding of the interaction between poplar and its endophytic bacteria has the potential to provide major breakthroughs that will improve the productivity of poplar. Endophytic bacteria can improve plant growth and development in a direct or indirect way. Direct plant growth promoting mechanisms may involve nitrogen fixation, production of plant growth regulators such as auxins, cytokinins and gibberellins, and suppression of stress ethylene synthesis by 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Endophytic bacteria can indirectly benefit the plant by preventing the growth or activity of plant pathogens through competition for space and nutrients, antibiosis, production of hydrolytic enzymes, inhibition of pathogen-produced enzymes or toxins, and through systemic induction of plant defense mechanisms. Examples of applications for custom endophyte-host partnerships include improved productivity and establishment of poplar trees on marginal soils and the phytoremediation of contaminated soils and groundwater. A systems biology approach to understand the synergistic interactions between poplar and its beneficial endophytic bacteria represents an important field of research, which is facilitated by the recent sequencing of the genomes of poplar and several of its endophytic bacteria.

  11. Ikke bare porno på mobilen

    DEFF Research Database (Denmark)

    Andersen, Tem Frank

    2013-01-01

    Den britiske børne- og ungdomsforsker professor Sonia Livingstone ved London School of Economics viser gennem en række interviews, at billeder af eksplicitte sexhandlinger er en velkendt del af den ungdommelige cirkulation af ’hverdagspornografisk’ materiale (Ringrose et al. 2012). ’Sexting’ er...... altså ikke bare porno på en mobilplatform. Det er handlinger og værgestrategier, som unge piger er nødt til at forholde sig til i hverdagen, mens drengene umiddelbart ser ud til at slippe relativt let udenom den chikane, der kan ligge i ’sexting’....

  12. Chirality in Bare and Passivated Gold Nanoclusters

    CERN Document Server

    Garzon, I L; Rodrigues-Hernandez, J I; Sigal, I; Beltran, M R; Michaelian, K

    2002-01-01

    Chiral structures have been found as the lowest-energy isomers of bare (Au$_{28}$ and Au$_{55}) and thiol-passivated (Au$_{28}(SCH$_{3})$_{16}$ and Au$_{38}$(SCH$_{3}$)$_{24}) gold nanoclusters. The degree of chirality existing in the chiral clusters was calculated using the Hausdorff chirality measure. We found that the index of chirality is higher in the passivated clusters and decreases with the cluster size. These results are consistent with the observed chiroptical activity recently reported for glutahione-passivated gold nanoclusters, and provide theoretical support for the existence of chirality in these novel compounds.

  13. Continuous steam hydrolysis of tulip poplar

    Energy Technology Data Exchange (ETDEWEB)

    Fieber, C.; Colcord, A.R.; Faass, S.; Muzzy, J.D.; Roberts, R.S.

    1982-08-01

    To produce ethanol from hardwood it is desirable to fractionate the hardwood in order to produce a relatively pure cellulosic pulp for dilute acid hydrolysis. An experimental investigation of continuous steam hydrolysis of tulip poplar wood chips indicates that over 90% of the lignin present can be extracted by 0.1N sodium hydroxide, resulting in a cellulose pulp containing over 90% hexosan. The study was performed using a Stake Technology, Ltd., continuous digester rated at one oven dry ton per hour of wood chips. The yields of hexosans, hexoses, xylan, xylose, lignin, furfural, acetic acid and methanol were determined as a function of residence time and steam pressure in the digester. The information provides a basis for establishing a material and energy balance for a hardwood to ethanol plant.

  14. Comparing growth rate in a mixed plantation (walnut, poplar and nurse trees with different planting designs: results from an experimental plantation in northern Italy

    Directory of Open Access Journals (Sweden)

    Francesco Pelleri

    2013-12-01

    Full Text Available 800x600 Results of a mixed plantation with poplar, walnut and nurse trees established in winter 2003 in Northern Italy, are reported. Main tree species (poplar and walnut were planted according to a rectangular design (10 x 11m, with different spacings and alternate lines. The experimental trial was carried out to verify the following working hypotheses: (i possibility to combine main trees with different growth levels (common walnut, hybrid walnut, and different poplar clones and test two different poplar and walnut spacings (5.0 and 7.4 m in the same plantation; (ii opportunity to reduce cultivation’s workload, in comparison with poplar monoculture, using mixtures with different poplar clones and N-fixing nurse trees; (iii verifying the growth pattern of two new poplar clones in comparison with the traditional clones cultivated for different purposes in Italy.The use of different valuable crop trees’ mixtures intercropped with nurse trees and shrubs (including N-fixing trees allows to decrease the cultivation’s workload. In fact, a heavy reduction of cultural practices - fertilizers, weed control, irrigation and pesticides applications (-61% are the main concurrent, supplementary benefits. The best growth performances (DBH and tree height, associated with the higher competition towards walnuts, were recorded with the new clones Lena and Neva in comparison with the I214 and Villafranca. The closer spacing (5 m between poplar and walnut trees was found to be unsuited to get merchantable poplars sized 30 cm without developing a heavy competition towards walnut trees. The wider spacing (7.4 m resulted vice versa suitable to get poplar trees sized as requested by veneer factories and to maintain an acceptable competitive level with walnut. Within this plantation design, a shorter rotation (8 yrs is needed for Lena and Neva clones in comparison with I214 and Villafranca (10 yrs. Walnut intercropped with poplar showed cone-shaped crowns, light

  15. Analysis of 4,664 high-quality sequence-finished poplar full-length cDNA clones and their utility for the discovery of genes responding to insect feeding

    Directory of Open Access Journals (Sweden)

    Douglas Carl J

    2008-01-01

    Full Text Available Abstract Background The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. Results As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa × P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones

  16. Investigation of Carbohydrate Compositions for Poplar Ⅰ-214 and Chinese Fir

    Institute of Scientific and Technical Information of China (English)

    HUANG Luohua; QIN Tefu; MAGARA Kengo

    2006-01-01

    The carbohydrate compositions of poplar Ⅰ-214 and Chinese fir were investigated by the methods of hydrolysis and HPLC.The result showed that the contents of glucose,xylose and arabinose in poplar Ⅰ-214 are higher than those in Chinese fir,while contents of rhamnose and mannose in poplar Ⅰ-214 are lower than those in Chinese fir.

  17. Do Bare Rocks Exist on the Moon?

    Science.gov (United States)

    Allen, Carlton; Bandfield, Joshua; Greenhagen, Benjamin; Hayne, Paul; Leader, Frank; Paige, David

    2017-01-01

    Astronaut surface observations and close-up images at the Apollo and Chang'e 1 landing sites confirm that at least some lunar rocks have no discernable dust cover. However, ALSEP (Apollo Lunar Surface Experiments Package) measurements as well as astronaut and LADEE (Lunar Atmosphere and Dust Environment Explorer) orbital observations and laboratory experiments possibly suggest that a fine fraction of dust is levitated and moves across and above the lunar surface. Over millions of years such dust might be expected to coat all exposed rock surfaces. This study uses thermal modeling, combined with Diviner (a Lunar Reconnaissance Orbiter experiment) orbital lunar eclipse temperature data, to further document the existence of bare rocks on the lunar surface.

  18. Investigating the Role of Extensin Proteins in Poplar Biomass Recalcitrance

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Margaret Brigham; Decker, Stephen R.; Bedinger, Patricia A.

    2016-04-13

    The biological conversion of cellulosic biomass to biofuel is hindered by cell wall recalcitrance, which can limit the ability of cellulases to access and break down cellulose. The purpose of this study was to investigate whether hydroxyproline-rich cell wall proteins (extensins) are present in poplar stem biomass, and whether these proteins may contribute to recalcitrance. Three classical extensin genes were identified in Populus trichocarpa through bioinformatic analysis of poplar genome sequences, with the following proposed names: PtEXTENSIN1 (Potri.001G019700); PtEXTENSIN2 (Potri.001G020100); PtEXTENSIN3 (Potri.018G050100). Tissue print immunoblots localized the extensin proteins in poplar stems to regions near the vascular cambium. Different thermochemical pretreatments reduced but did not eliminate hydroxyproline (Hyp, a proxy for extensins) from the biomass. Protease treatment of liquid hot water-pretreated poplar biomass reduced Hyp content by a further 16% and increased subsequent glucose yield by 20%. These data suggest that extensins may contribute to recalcitrance in pretreated poplar biomass, and that incorporating protease treatment into pretreatment protocols could result in a small but significant increase in the yield of fermentable glucose.

  19. Growing poplars for research with and without mycorrhizas

    Directory of Open Access Journals (Sweden)

    Anna eMüller

    2013-08-01

    Full Text Available During the last decades the importance of the genus Populus increased because the poplar genome has been sequenced and molecular tools for basic research are available. Furthermore, poplar species occur in different habitats and harbour large genetic variation, which can be exploited for economic applications and for increasing our knowledge on the basic molecular mechanisms of the woody life style. Poplars are, therefore, employed to unravel the molecular mechanisms of wood formation, stress tolerance, tree nutrition and interaction with other organisms such as pathogens or mycorrhiza. The basis of these investigations is the reproducible production of homogeneous plant material. In this method paper we describe techniques and growth conditions for the in vitro propagation of different poplar species (Populus × canescens, P. trichocarpa, P. tremula and P. euphratica and ectomycorrhizal fungi (Laccaria bicolor, Paxillus involutus as well as for their co-cultivation for ectomycorrhizal synthesis. Maintenance and plant preparation require different multiplication and rooting media. Growth systems to cultivate poplars under axenic conditions in agar and sand cultures with and without mycorrhizal fungi are described. Transfer of the plants from in vitro to in situ conditions is critical and hardening is important to prevent high mortality. Growth and vitality of the trees in vitro and outdoors with and without ectomycorrhizas are reported.

  20. Proteome Analysis of Poplar Seed Vigor.

    Science.gov (United States)

    Zhang, Hong; Wang, Wei-Qing; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Seed vigor is a complex property that determines the seed's potential for rapid uniform emergence and subsequent growth. However, the mechanism for change in seed vigor is poorly understood. The seeds of poplar (Populus × Canadensis Moench), which are short-lived, were stored at 30 °C and 75 ± 5% relative humidity for different periods of time (0-90 days) to obtain different vigor seeds (from 95 to 0% germination). With decreasing seed vigor, the temperature range of seed germination became narrower; the respiration rate of the seeds decreased markedly, while the relative electrolyte leakage increased markedly, both levelling off after 45 days. A total of 81 protein spots showed a significant change in abundance (≥ 1.5-fold, P seeds with different vigor. Of the identified 65 proteins, most belonged to the groups involved in metabolism (23%), protein synthesis and destination (22%), energy (18%), cell defense and rescue (17%), and storage protein (15%). These proteins accounted for 95% of all the identified proteins. During seed aging, 53 and 6 identified proteins consistently increased and decreased in abundance, respectively, and they were associated with metabolism (22%), protein synthesis and destination (22%), energy (19%), cell defense and rescue (19%), storage proteins (15%), and cell growth and structure (3%). These data show that the decrease in seed vigor (aging) is an energy-dependent process, which requires protein synthesis and degradation as well as cellular defense and rescue.

  1. The growth process of natural poplar-birch forests

    Institute of Scientific and Technical Information of China (English)

    LAN Shibo; LUO Xu; LUO Yuliang

    2006-01-01

    With a combination of permanent and temporary sample plots,we investigated the growth conditions of natural poplar-birch forests.The forests were divided into four site classes,using statistical and analytical techniques in a quantitative model,in descending order where site class I was the best.On this basis,the growth of natural poplar-birch forests in the different site classes was studied.The growth processes of height and diameter at breast height were divided into three stages:a fast growing period,a stable growing period and a slow growing period.Results of this study provide a theoretical basis for the directive cultivation of natural poplar-birch forests.

  2. Hydrothermal pretreatment conditions to enhance ethanol production from poplar biomass.

    Science.gov (United States)

    Negro, Maria José; Manzanares, Paloma; Ballesteros, Ignacio; Oliva, Jose Miguel; Cabañas, Araceli; Ballesteros, Mercedes

    2003-01-01

    Pretreatment has been recognized as a key step in enzyme-based conversion processes of lignocellulose biomass to ethanol. The aim of this study is to evaluate two hydrothermal pretreatments (steam explosion and liquid hot water) to enhance ethanol production from poplar (Populus nigra) biomass by a simultaneous saccharification and fermentation (SSF) process. The composition of liquid and solid fractions obtained after pretreatment, enzymatic digestibility, and ethanol production of poplar biomass pretreated at different experimental conditions was analyzed. The best results were obtained in steam explosion pretreatment at 210 C and 4 min, taking into account cellulose recovery above 95%, enzymatic hydrolysis yield of about 60%, SSF yield of 60% of theoretical, and 41% xylose recovery in the liquid fraction. Large particles can be used for poplar biomass in both pretreatments, since no significant effect of particle size on enzymatic hydrolysis and SSF was obtained.

  3. Stem taper equations for poplars growing on farmland in Sweden

    Institute of Scientific and Technical Information of China (English)

    Birger Hjelm

    2013-01-01

    We developed a simple polynomial taper equation for poplars growing on former farmland in Sweden and also evaluated the performance of some well-known taper equations.In Sweden there is an increasing interest in the use of poplar.Effective management of poplar plantations for high yield production would be facilitated by taper equations providing better predictions of stem volume than currently available equations.In the study a polynomial stem taper equation with five parameters was established for individual poplar trees growing on former farmland.The outputs of the polynomial taper equation were compared with five published equations.Data for fitting the equations were collected from 69 poplar trees growing at 37 stands in central and southern Sweden (lat.55-60° N).The mean age of the stands was 21 years (range 14-43),the mean density 984 stemsha-1 (198-3,493),and the mean diameter at breast height (outside bark) 25 cm (range 12-40).To verify the tested equations,performance of accuracy and precision diameter predictions at seven points along the stem was closely analyzed.Statistics used for evaluation of the equations indicated that the variable exponent taper equation presented by Kozak (1988) performed best and can be recommended.The stem taper equation by Kozak (1988) recommended in the study is likely to be beneficial for optimising the efficiency and profitability of poplar plantation management.The constructed polynomial equation and the segmented equation presented by Max & Burkhart (1976) were second and third ranked.Due to the statistical complexity of Kozak's equation,the constructed polynomial equation is alternatively recommended when a simple model is requested and larger bias is accepted.

  4. Sulfate Metabolites of 4-Monochlorobiphenyl in Whole Poplar Plants

    OpenAIRE

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2012-01-01

    4-Monochlorobiphenyl (PCB3) has been proven to be transformed into hydroxylated metabolites of PCB3 (OH-PCB3s) in whole poplar plants in our previous work. However, hydroxylated metabolites of PCBs, including OH-PCB3s, as the substrates of sulfotransferases have not been studied in many organisms including plants in vivo. Poplar (Populus deltoides × nigra, DN34) was used to investigate the further metabolism from OH-PCB3s to PCB3 sulfates because it is a model plant and one that is frequently...

  5. Effect of different biochars on Nitrogen uptake in poplar trees

    Science.gov (United States)

    George, Elizabeth; Tonon, Giustino; Scandellari, Francesca

    2014-05-01

    Influence of biochar on soil nitrogen transformation and plant uptake has been reported. This paper presents preliminary results of plant N uptake in poplars by using 15N isotope tracer approach Two types of biochar were applied to two sets of pots containing only sand and each pot received a pre-rooted poplar cutting. Half of the pots were inoculated with commercial mycorrhizal gel and the other half were left without. It is intended to provide information on how biochar, mycorrhiza and root interaction mediate nitrogen uptake and organ allocation.

  6. Selection of black poplars for water use efficiency

    Directory of Open Access Journals (Sweden)

    Orlović Saša S.

    2002-01-01

    Full Text Available Photosynthesis, transpiration, water use efficiency (WUE and biomass production have been investigated in nine black poplar clones (section Aigeiros in three field experiments. Eastern cottonwood clones (Populus deltoides had the highest net photosynthesis and water use efficiency. European black poplar clones had the highest transpiration intensity. Correlation analysis showed that net photosynthesis was in a high positive correlation with biomass. Medium negative correlations existed between WUE and net photosynthesis, transpiration and biomass and WUE and biomass. The study showed a pronounced interclonal variability of the physiological and growth characters under study.

  7. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Rige, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  8. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  9. Role of water in the tribochemical removal of bare silicon

    Science.gov (United States)

    Chen, Cheng; Xiao, Chen; Wang, Xiaodong; Zhang, Peng; Chen, Lei; Qi, Yaqiong; Qian, Linmao

    2016-12-01

    Nanowear tests of bare silicon against a SiO2 microsphere were conducted in air (relative humidity [RH] = 0%-89%) and water using an atomic force microscope. Experimental results revealed that the water played an important role in the tribochemical wear of the bare silicon. A hillock-like wear trace with a height of 0.7 nm was generated on the bare silicon surface in dry air. As the RH increased, the wear depth increased and reached the maximum level in water. Analysis of frictional dissipated energy suggested that the wear of the bare silicon was not dominated by mechanical interactions. High-resolution transmission electron microscopy detection demonstrated that the silicon atoms and crystal lattice underneath the worn area maintained integral perfectly and thus further confirmed the tribochemical wear mechanism of the bare silicon. Finally, the role of water in the tribochemical wear of the bare silicon may be explained by the following three aspects: the hydroxylation by hydroxyl ions auto-ionized in water, the hydrolytic reaction of water molecules, and the dissolution of the tribochemical product SiOmHn in liquid water. With increasing RH, a greater water amount would adsorb to the Si/SiO2 interface and induce a more serious tribochemical wear on the bare silicon surface. The results of this paper may provide further insight into the tribochemical removal mechanism of bare monocrystalline silicon and furnish the wider reaction cognition for chemical mechanical polishing.

  10. The Semantics of Proper Names and Other Bare Nominals

    Science.gov (United States)

    Izumi, Yu

    2012-01-01

    This research proposes a unified approach to the semantics of the so-called bare nominals, which include proper names (e.g., "Mary"), mass and plural terms (e.g., "water," "cats"), and articleless noun phrases in Japanese. I argue that bare nominals themselves are monadic predicates applicable to more than one…

  11. Application of pre-emergence herbicides in poplar nursery production

    Institute of Scientific and Technical Information of China (English)

    Verica Vasic; Sasa Orlovic; Predrag Pap; Branislav Kovacevic; Milan Drekic; Leopold Poljakovic Pajnik; Zoran Galic

    2015-01-01

    In addition to pests and diseases, weeds are a major problem in poplar nursery production. The possibili-ties of herbicide application in juvenile poplar growth were researched, taking into account that weeds are one of the main limiting factors. The following pre-emergence herbi-cides were tested: acetochlor, S-metolachlor, metribuzin, oxifluorfen, and dimethenamid during two vegetation sea-sons at two locations, which differed by the soil physico-chemical characteristics. The study results show that the number of weeds on sample plots was significantly reduced by the tested herbicides when compared to control plots. The highest reduction in the number of weeds was achieved using the herbicides acetochlor and metribuzin. However, me-tribuzin showed a phytotoxic effect on sandy soil. Metribu-zin application is recommended only on the soils with higher contents of organic matter, where the phytotoxic effect was absent. Acetochlor, S-metolachlor, oxifluorfen, and dime-thenamid were not phytotoxic to poplars and can be used for weed suppression in the production of poplar plants.

  12. Transgenic manipulation of the metabolism of polyamines in poplar cells

    Science.gov (United States)

    Pratiksha Bhatnagar; Bernadette M. Glasheen; Suneet K. Bains; Stephanie L. Long; Rakesh Minocha; Christian Walter; Subhash C. Minocha

    2001-01-01

    The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra 3 maximowiczii) expressing a...

  13. Enhanced Built-Up and Bareness Index (EBBI for Mapping Built-Up and Bare Land in an Urban Area

    Directory of Open Access Journals (Sweden)

    I Wayan Arthana

    2012-10-01

    Full Text Available Remotely sensed imagery is a type of data that is compatible with the monitoring and mapping of changes in built-up and bare land within urban areas as the impacts of population growth and urbanisation increase. The application of currently available remote sensing indices, however, has some limitations with respect to distinguishing built-up and bare land in urban areas. In this study, a new index for transforming remote sensing data for mapping built-up and bare land areas is proposed. The Enhanced Built-Up and Bareness Index (EBBI is able to map built-up and bare land areas using a single calculation. The EBBI is the first built-up and bare land index that applies near infrared (NIR, short wave infrared (SWIR, and thermal infrared (TIR channels simultaneously. This new index was applied to distinguish built-up and bare land areas in Denpasar (Bali, Indonesia and had a high accuracy level when compared to existing indices. The EBBI was more effective at discriminating built-up and bare land areas and at increasing the accuracy of the built-up density percentage than five other indices.

  14. Investment appraisal of a poplar plantation aged 42 years

    Directory of Open Access Journals (Sweden)

    Keča Ljiljana

    2013-01-01

    Full Text Available Commercial profitability of poplar cultivation was analyzed in an artificial poplar plantation in Serbia. The aim of this study was to validate the invested financial means in the artificial poplar plantation, on the basis of the analysis of costs and receipts during a 42-year rotation, on alluvial semigley, at a discount rate of 12%. Methods of dynamic investment calculation (net present value - NPV, internal rate of return - IRR, benefit-cost method - B/C and payback period - PBP were used. The investigated plantations were established from Populus x euramericana cl. I-214, with a planting spacing of 6 x 3 m. At the calculation discount rate of 12%, the project for the production cycle of 42 years was not cost-effective from the economic aspect. The discount rate of 6% can be accepted in the studied plot because of the better site (alluvial semigley, but the oldness of the stand is unfavourable. For the studied sample plot, IRR was 5.51 %. B/C at r=12% in the study compartment was 0.24. The analysis shows that PBP is practically unacceptable for the investor at the discount rate of 6%. In practice, it is necessary to improve the position of producers in getting financial means for investment in poplar cultivation, so as to stimulate the establishment of artificial poplar plantations, especially in the private sector (on private land. [Projekat Ministarstva nauke Republike Srbije, br. TR 37008, TR 31041 and Value chain of non-wood forest products and its role in development of forestry sector in Serbia

  15. Isoprene emission-free poplars--a chance to reduce the impact from poplar plantations on the atmosphere.

    Science.gov (United States)

    Behnke, Katja; Grote, Rüdiger; Brüggemann, Nicolas; Zimmer, Ina; Zhou, Guanwu; Elobeid, Mudawi; Janz, Dennis; Polle, Andrea; Schnitzler, Jörg-Peter

    2012-04-01

    • Depending on the atmospheric composition, isoprene emissions from plants can have a severe impact on air quality and regional climate. For the plant itself, isoprene can enhance stress tolerance and also interfere with the attraction of herbivores and parasitoids. • Here, we tested the growth performance and fitness of Populus × canescens in which isoprene emission had been knocked down by RNA interference technology (PcISPS-RNAi plants) for two growing seasons under outdoor conditions. • Neither the growth nor biomass yield of the PcISPS-RNAi poplars was impaired, and they were even temporarily enhanced compared with control poplars. Modelling of the annual carbon balances revealed a reduced carbon loss of 2.2% of the total gross primary production by the absence of isoprene emission, and a 6.9% enhanced net growth of PcISPS-RNAi poplars. However, the knock down in isoprene emission resulted in reduced susceptibility to fungal infection, whereas the attractiveness for herbivores was enhanced. • The present study promises potential for the use of non- or low-isoprene-emitting poplars for more sustainable and environmentally friendly biomass production, as reducing isoprene emission will presumably have positive effects on regional climate and air quality. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  16. Conservation status of white poplar (Populus alba L. and black poplar (Populus nigra L. in the territory of Great War Island

    Directory of Open Access Journals (Sweden)

    Šijačić-Nikolić Mirjana

    2014-01-01

    Full Text Available T he paper describes t he conservation status of white poplar (Populus alba L. and black poplar (Populus nigra L. in the territory of Great War Island. The activities of in situ and ex situ gene pool conservation have been defined in order to preserve and expand the populations of the above species, as carriers of complex wetland forest ecosystems.

  17. A Syntactic Study on Bare Infinitive and Infinitival to

    Institute of Scientific and Technical Information of China (English)

    LIU Jing

    2014-01-01

    Infinitives which consist of bare infinitive and infinitival to are imperative in linguistic studies. And both of the two kinds of infinitives do not indicate person, tense and number. This research aims to analyze the properties, similarities and differ-ences between bare infinitive and infinitival to from the perspective of syntax. Thus, it enables us to attain a uniform characteriza-tion of the infinitival to and bare infinitive on the syntactic level and help us to understand these two kinds of infinitives better.

  18. Relationship between trophic component of different poplar strains and occurrence of Saperda poplnea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An experimental area of poplar was established in Songyuan of Jilin Province in 1999 for testing the resistance of different poplar stains to Saperda poplnea. Incidence of S. poplnea on ten poplar strains were investigated, and the main trophic component of branches of these poplar trees were measured and analyzed in April 2001. The results showed that there existed significant difference in population size of S. poplnea on different poplar strains, and the branches of these poplar strains have significant difference in nutrient component and content of amino acids. The population size of this pest had a significantly posi-tive correlation with dissolvable total sugar and water content but had no significant correlation with content of total nitrogen and protein nitrogen.

  19. EAARL Coastal Topography--Pearl River Delta 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Pearl River Delta in Louisiana and Mississippi was produced from remotely sensed,...

  20. EAARL Coastal Topography--Northeast Barrier Islands 2007: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northeast coastal barrier islands in New York and New Jersey was produced from...

  1. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  2. EAARL Coastal Topography--Pearl River Delta 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Pearl River Delta in Louisiana and Mississippi was produced from remotely sensed,...

  3. EAARL Coastal Topography--Chandeleur Islands, Louisiana, 2010: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the Chandeleur Islands, Louisiana, was produced from remotely...

  4. EAARL Bare Earth Topography-Fire Island National Seashore

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model or DEM) of Fire Island National Seashore was produced from remotely-sensed,...

  5. EAARL Coastal Topography--Northeast Barrier Islands 2007: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northeast coastal barrier islands in New York and New Jersey was produced from...

  6. EAARL Topography-Vicksburg National Millitary Park 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Vicksburg National Military Park in Mississippi was produced from remotely...

  7. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  8. Temporal construals of bare predicates in Mandarin Chinese

    NARCIS (Netherlands)

    Sun, Hongyuan

    2014-01-01

    This dissertation contributes to the research on tense and eventualities across languages. It presents the first systematic investigation and detailed theoretical analysis of the temporal interpretations of sentences with bare (aspectually unmarked) predicates in Mandarin. Traditionally considered

  9. EAARL Coastal Topography--Chandeleur Islands, Louisiana, 2010: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the Chandeleur Islands, Louisiana, was produced from remotely...

  10. EAARL Bare Earth Topography-Fire Island National Seashore

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model or DEM) of Fire Island National Seashore was produced from remotely-sensed,...

  11. EAARL Topography-Vicksburg National Millitary Park 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Vicksburg National Military Park in Mississippi was produced from remotely...

  12. Genome Enabled Discovery of Carbon Sequestration Genes in Poplar

    Energy Technology Data Exchange (ETDEWEB)

    Filichkin, Sergei; Etherington, Elizabeth; Ma, Caiping; Strauss, Steve

    2007-02-22

    The goals of the S.H. Strauss laboratory portion of 'Genome-enabled discovery of carbon sequestration genes in poplar' are (1) to explore the functions of candidate genes using Populus transformation by inserting genes provided by Oakridge National Laboratory (ORNL) and the University of Florida (UF) into poplar; (2) to expand the poplar transformation toolkit by developing transformation methods for important genotypes; and (3) to allow induced expression, and efficient gene suppression, in roots and other tissues. As part of the transformation improvement effort, OSU developed transformation protocols for Populus trichocarpa 'Nisqually-1' clone and an early flowering P. alba clone, 6K10. Complete descriptions of the transformation systems were published (Ma et. al. 2004, Meilan et. al 2004). Twenty-one 'Nisqually-1' and 622 6K10 transgenic plants were generated. To identify root predominant promoters, a set of three promoters were tested for their tissue-specific expression patterns in poplar and in Arabidopsis as a model system. A novel gene, ET304, was identified by analyzing a collection of poplar enhancer trap lines generated at OSU (Filichkin et. al 2006a, 2006b). Other promoters include the pGgMT1 root-predominant promoter from Casuarina glauca and the pAtPIN2 promoter from Arabidopsis root specific PIN2 gene. OSU tested two induction systems, alcohol- and estrogen-inducible, in multiple poplar transgenics. Ethanol proved to be the more efficient when tested in tissue culture and greenhouse conditions. Two estrogen-inducible systems were evaluated in transgenic Populus, neither of which functioned reliably in tissue culture conditions. GATEWAY-compatible plant binary vectors were designed to compare the silencing efficiency of homologous (direct) RNAi vs. heterologous (transitive) RNAi inverted repeats. A set of genes was targeted for post transcriptional silencing in the model Arabidopsis system; these include the floral

  13. Bare and effective fluid description in brane world cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Norman [Universidad de Santiago, Departamento de Fisica, Facultad de Ciencia, Casilla 307, Santiago (Chile); Lepe, Samuel; Saavedra, Joel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Casilla 4950, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile)

    2010-03-15

    An effective fluid description, for a brane world model in five dimensions, is discussed for both signs of the brane tension. We found several cosmological scenarios where the effective equation differs widely from the bare equation of state. For universes with negative brane tension, with a bare fluid satisfying the strong energy condition, the effective fluid can cross the barrier {omega} {sub eff}=-1. (orig.)

  14. Impact of Biofuel Poplar Cultivation on Ground-Level Ozone and Premature Human Mortality Depends on Cultivar Selection and Planting Location.

    Science.gov (United States)

    Ashworth, Kirsti; Wild, Oliver; Eller, Allyson S D; Hewitt, C Nick

    2015-07-21

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. The cultivation of biofuel feedstocks will contribute to future land use change, altering the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 commercially available poplar hybrids to assess the impact that the large-scale cultivation of poplar for use as a biofuel feedstock will have on air quality, specifically ground-level ozone concentrations, in Europe. We show that the increases in ground-level ozone across Europe will increase the number of premature deaths attributable to ozone pollution each year by up to 6%. Substantial crop losses (up to ∼9 Mt y(-1) of wheat and maize) are also projected. We further demonstrate that these impacts are strongly dependent on the location of the poplar plantations, due to the prevailing meteorology, the population density, and the dominant crop type of the region. Our findings indicate the need for a concerted and centralized decision-making process that considers all aspects of future land use change in Europe, and not just the effect on greenhouse gas emissions.

  15. An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation.

    Science.gov (United States)

    Hu, Jianjun; Zhang, Jin; Chen, Xingling; Lv, Jinhui; Jia, Huixia; Zhao, Shutang; Lu, Mengzhu

    2017-01-01

    To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar) and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0%) compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture) after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations.

  16. The arbuscular mycorrhizal status of poplar clones selected for phytoremediation of soils contaminated with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, T.; Radimszky, L.; Nemeth, T. [Research Inst. for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Budapest (Hungary)

    2005-04-01

    The aim of this work was to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) species in fine-roots of poplar clones. Roots of 7 poplar clones were sampled from a 1-year-old trial established at an industrial site strongly polluted with heavy metals at Balatonfuezfoe, Hungary. The poplar clones have shown variable degrees of colonization by AMF, suggesting differential host susceptibility or mycorrhizal dependency. After outplanting the percentage of poplar survival was strongly correlated with the frequency of AMF infection. Two clones that survived at the lowest ratio after outplanting had not been colonized by AMF in contrast to those which survived to a much higher extent. (orig.)

  17. Poplar maintains zinc homeostasis with heavy metal genes HMA4 and PCS1

    Science.gov (United States)

    Adams, Joshua P.; Adeli, Ardeshir; Hsu, Chuan-Yu; Harkess, Richard L.; Page, Grier P.; dePamphilis, Claude W.; Schultz, Emily B.; Yuceer, Cetin

    2011-01-01

    Perennial woody species, such as poplar (Populus spp.) must acquire necessary heavy metals like zinc (Zn) while avoiding potential toxicity. Poplar contains genes with sequence homology to genes HMA4 and PCS1 from other species which are involved in heavy metal regulation. While basic genomic conservation exists, poplar does not have a hyperaccumulating phenotype. Poplar has a common indicator phenotype in which heavy metal accumulation is proportional to environmental concentrations but excesses are prevented. Phenotype is partly affected by regulation of HMA4 and PCS1 transcriptional abundance. Wild-type poplar down-regulates several transcripts in its Zn-interacting pathway at high Zn levels. Also, overexpressed PtHMA4 and PtPCS1 genes result in varying Zn phenotypes in poplar; specifically, there is a doubling of Zn accumulation in leaf tissues in an overexpressed PtPCS1 line. The genomic complement and regulation of poplar highlighted in this study supports a role of HMA4 and PCS1 in Zn regulation dictating its phenotype. These genes can be altered in poplar to change its interaction with Zn. However, other poplar genes in the surrounding pathway may maintain the phenotype by inhibiting drastic changes in heavy metal accumulation with a single gene transformation. PMID:21504875

  18. Killing, letting die and the bare difference argument.

    Science.gov (United States)

    Perrett, Roy W

    1996-04-01

    I believe that there is no intrinsic moral difference between killing and letting die. That is, there is no difference that depends solely on the distinction between an act and an omission. I also believe that we can reasonably establish this thesis by appeal to the Bare Difference Argument. The form of this argument involves considering two imaginary cases in which there are no morally relevant differences present, save the bare difference that one is a case of killing and one a case of letting die. But in the pair of cases under consideration this bare difference makes no moral difference. Hence it cannot be that the bare difference between killing and letting die is in itself a morally important difference. Winston Nesbitt has recently argued that the Bare Difference Argument fails because "the examples produced typically possess a feature which makes their use in this context illegitimate, and that when modified to remove this feature, they provide support for the view which they were designed to undermine". I argue that Nesbitt misunderstands the logic of the Bare Difference Argument and that accordingly his objections are mistaken.

  19. Biomass production and carbon sequestration of a short-rotation forest with different poplar clones in northwest China.

    Science.gov (United States)

    Meifang, Yan; Lu, Wang; Honghui, Ren; Xinshi, Zhang

    2017-05-15

    Short Rotation Forestry (SRF) is of interest as producers of biomass for bio-energy, but also as carbon (C) sinks to mitigate CO2 emission. To investigate biomass production and C sequestration of SRF, ecosystem C stock (including C stored in tree biomass, litter and soil), NPP (net primary productivity), heterotrophic respiration (Rh) and NEP (net ecosystem productivity) of three poplar clone plantations were estimated by repeated field sampling in northwest China. Ecosystem C stock (105.62MgCha(-1)) was significantly lower in PB (P. balsamifera) stand than in PD (P. deltoids) and PE (P.×euramericana) stands (Pplantations all acted as C sinks, averagely absorbing 3.45MgCha(-1) during a year. Our results suggest that clone type is a main factor influencing C sequestration capacity of a plantation, along with determining the amount of biomass yield. The success of poplar plantations as a bio-energy resource largely depends on the selection of hybrid varieties. Copyright © 2017. Published by Elsevier B.V.

  20. Cadmium phytoextraction potential of poplar clones (Populus spp.)

    Energy Technology Data Exchange (ETDEWEB)

    Pilipovic, A.; Orlovic, S.; Petrovic, N. [Faculty of Agriculture, Inst. of Lowland Forestry and Environment, Novi Sad (Czechoslovakia); Nikolic, N.; Krstic, B. [Faculty of Natural Sciences, Dept. of Biology and Ecology, Novi Sad (Czechoslovakia)

    2005-04-01

    Biomass production, leaf number and area, photosynthetic and dark respiration rates, leaf concentration of photosynthetic pigments, nitrate reductase activity, as well as cadmium concentrations in leaves, stem, and roots were measured in poplar clones PE 4/68, B-229, 665, and 45/51. Plants were grown hydroponically under controlled conditions and treated with two different cadmium (Cd) concentrations (10{sup -5} and 10{sup -7} M) in the same background solution (Hoagland's solution). The presence of Cd did not cause serious disturbance of growth and physiological parameters in the studied poplar clones. Cd concentrations in plant tissues reflected external concentrations. In treated plants, root contents increased from 38.57 to 511.51 ppm, leaf contents from 0.91 to 7.50, while stem contents ranged from 1.37 to 9.50 ppm. (orig.)

  1. Nitrogen ion utilization by tulip poplar (Liriodendron tulipifera L. ) seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Mann, L.K.

    1982-01-01

    Growth responses of one-year-old tulip poplar seedlings were determined for different nitrogen sources (HN/sub 4/NO/sub 3/, NH+/sub 4/, NO-/sub 3/, no nitrogen) at 336 ppm N in nutrient culture. At the end of three months, there were no significant differences in growth observed among treatments in terms of stem elongation, leaf area, and leaf size. After four months, however, seedlings of the NH/sub 4/NO/sub 3/ treatment exhibited significantly (P<0.05) greater growth (final weight gain and stem elongation) than all other nitrogen sorces. Growth was slightly less for the NO-/sub 3/ treatment plants, but compared with NH+/sub 4/ and no nitrogen treatment, both NH/sub 4/NO/sub 3/ and NO-/sub 3/ treatments exhibited significantly greater growth responses. NO-/sub 3/ is recommended as the sole nitrogen source, especially for small seedlings of tulip poplar.

  2. Heat transfer mechanisms in poplar wood undergoing torrefaction

    Science.gov (United States)

    Sule, Idris O.; Mahmud, Shohel; Dutta, Animesh; Tasnim, Syeda Humaira

    2016-03-01

    Torrefaction, a thermal treatment process of biomass, has been proved to improve biomass combustible properties. Torrefaction is defined as a thermochemical process in reduced oxygen condition and at temperature range from 200 to 300 °C for shorter residence time whereby energy yield is maximized, can be a bridging technology that can lead the conventional system (e.g. coal-fired plants) towards a sustainable energy system. In efforts to develop a commercial operable torrefaction reactor, the present study examines the minimum input condition at which biomass is torrefied and explores the heat transfer mechanisms during torrefaction in poplar wood samples. The heat transfer through the wood sample is numerically modeled and analyzed. Each poplar wood is torrefied at temperature of 250, 270, and 300 °C. The experimental study shows that the 270 °C-treatment can be deduced as the optimal input condition for torrefaction of poplar wood. A good understanding of heat transfer mechanisms can facilitate the upscaling and downscaling of torrefaction process equipment to fit the feedstock input criteria and can help to develop treatment input specifications that can maximize process efficiency.

  3. Barcoding poplars (Populus L. from western China.

    Directory of Open Access Journals (Sweden)

    Jianju Feng

    Full Text Available BACKGROUND: Populus is an ecologically and economically important genus of trees, but distinguishing between wild species is relatively difficult due to extensive interspecific hybridization and introgression, and the high level of intraspecific morphological variation. The DNA barcoding approach is a potential solution to this problem. METHODOLOGY/PRINCIPAL FINDINGS: Here, we tested the discrimination power of five chloroplast barcodes and one nuclear barcode (ITS among 95 trees that represent 21 Populus species from western China. Among all single barcode candidates, the discrimination power is highest for the nuclear ITS, progressively lower for chloroplast barcodes matK (M, trnG-psbK (G and psbK-psbI (P, and trnH-psbA (H and rbcL (R; the discrimination efficiency of the nuclear ITS (I is also higher than any two-, three-, or even the five-locus combination of chloroplast barcodes. Among the five combinations of a single chloroplast barcode plus the nuclear ITS, H+I and P+I differentiated the highest and lowest portion of species, respectively. The highest discrimination rate for the barcodes or barcode combinations examined here is 55.0% (H+I, and usually discrimination failures occurred among species from sympatric or parapatric areas. CONCLUSIONS/SIGNIFICANCE: In this case study, we showed that when discriminating Populus species from western China, the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions. Meanwhile, combining the ITS region with chloroplast regions may improve the barcoding success rate and assist in detecting recent interspecific hybridizations. Failure to discriminate among several groups of Populus species from sympatric or parapatric areas may have been the result of incomplete lineage sorting, frequent interspecific hybridizations and introgressions. We agree with a previous proposal for constructing a tiered barcoding system in

  4. Evaluation of Lower East Fork Poplar Creek Mercury Sources

    Energy Technology Data Exchange (ETDEWEB)

    Watson, David B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brooks, Scott C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mathews, Teresa J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevelhimer, Mark S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeRolph, Chris [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ketelle, Richard [East Tennessee Technology Park (ETTP), Oak Ridge, TN (United States)

    2016-06-01

    This report summarizes a 3-year research project undertaken to better understand the nature and magnitude of mercury (Hg) fluxes in East Fork Poplar Creek (EFPC). This project addresses the requirements of Action Plan 1 in the 2011 Oak Ridge Reservation-wide Comprehensive Environmental Response, Compensation, and Liability Act Five Year Review (FYR). The Action Plan is designed to address a twofold 2011 FYR issue: (1) new information suggests mobilization of mercury from the upper and lower EFPC streambeds and stream banks is the primary source of mercury export during high-flow conditions, and (2) the current Record of Decision did not address the entire hydrologic system and creek bank or creek bed sediments. To obtain a more robust watershed-scale understanding of mercury sources and processes in lower EFPC (LEFPC), new field and laboratory studies were coupled with existing data from multiple US Department of Energy programs to develop a dynamic watershed and bioaccumulation model. LEFPC field studies for the project focused primarily on quantification of streambank erosion and an evaluation of mercury dynamics in shallow groundwater adjacent to LEFPC and potential connection to the surface water. The approach to the stream bank study was innovative in using imagery from kayak floats’ surveys from the headwaters to the mouth of EFPC to estimate erosion, coupled with detailed bank soil mercury analyses. The goal of new field assessments and modeling was to generate a more holistic and quantitative understanding of the watershed and the sources, flux, concentration, transformation, and bioaccumulation of inorganic mercury (IHg) and methylmercury (MeHg). Model development used a hybrid approach that dynamically linked a spreadsheet-based physical and chemical watershed model to a systems dynamics, mercury bioaccumulation model for key fish species. The watershed model tracks total Hg and MeHg fluxes and concentrations by examining upstream inputs, floodplain

  5. Contribution factor of wood properties of three poplar clones to strength of laminated veneer lumber

    Science.gov (United States)

    Fucheng Bao; Feng Fu; Elvin Choong; Chung-Yun Hse

    2001-01-01

    The term "Contribution Factor" (c.) was introduced in this paper to indicate the contribution ratio of solid wood properties to laminated veneer lumber (LVL) strength. Three poplar (Populus sp.) clones were studied, and the results showed that poplar with good solid wood properties has high Contribution Factor. The average Contribution...

  6. Key factors for causing poplar Ice Nucleation Active bacterial canker and its control techniques

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The isolation, culture and the active determination of poplar ice nucleation active (INA) bacteria and the inoculation tests in laboratory and field were conducted, and the varieties, distribution and number of poplar INA bacteria and its pathogenicity and freezing injury property were determined. The study results showed that the INA bacteria widely spread on poplar in Northeast China and caused the frozen injury for poplar under the frost condition in Spring or Autumn, which was the key factor to induce INA bacterial canker. Through evaluation and investigation of different poplar varieties and inoculation tests, fine disease-resistant varieties and strains of poplar suitable for Northeast China were selected. Further tests for strong seedling showed that burying cuttings in sand and covering with plastic film could effectively avoid the frostbite, frozen and drought damage, reduce INA bacteria infection, and promote poplar growth. INA bacterial canker was detected early by highly specialized antiserums of INA bacteria and the agglutinated test of ring-shaped boundary surface. The inducers such as streptomycin, phenylmercuric acetae, salicylic acid and heat-killed bacteria to immerse cuttings, have obvious induced disease-resistant effect. Before poplar sprouted in early spring, through spraying the solution of frostbite agent, the control effect also was obvious.

  7. WUS and STM-based reporter genes for studying meristem development in poplar

    Science.gov (United States)

    We describe the development of a reporter system for monitoring meristem initiation in poplar using promoters of poplar homologs to the meristem-active regulatory genes WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM). When ~3 kb of the 5’ flanking regions of close homologs were used to drive expression o...

  8. Semantic coherence in English accusative-with-bare-infinitive constructions

    DEFF Research Database (Denmark)

    Jensen, Kim Ebensgaard

    2013-01-01

    Drawing on usage-based cognitively oriented construction grammar, this paper investigates the patterns of coattraction of items that appear in the two VP positions (the VP in the matrix clause, and the VP in the infinitive subordinate clause) in the English accusative-with-bare-infinitive constru......Drawing on usage-based cognitively oriented construction grammar, this paper investigates the patterns of coattraction of items that appear in the two VP positions (the VP in the matrix clause, and the VP in the infinitive subordinate clause) in the English accusative......-with-bare-infinitive construction. The main methodological framework is that of covarying collexeme analysis, which, through statistical corpus analysis, allows for the analyst to address the semantics of a construction. Using this method on data from the BNC, the ultimate purpose of the paper is to address the underlying semantic...... relations of English accusatives-with-bare-infinitives through the relations of semantic coherence between the two VPs....

  9. Pulping performance of transgenic poplar with depressed Caffeoyl-CoA O-methyltransferase

    Institute of Scientific and Technical Information of China (English)

    WEI JianHua; WANG YanZhen; WANG HongZhi; LI RuiFen; LIN Nan; MA RongCai; QU LeQing; SONG YanRu

    2008-01-01

    This paper evaluated pulping performance of 3-year-old field-grown transgenic poplar (Populus tremula × Populus alba). The transgenic poplar with anti-sense CCoAOMT had an about 13% decreased lignin content, in which a slight increment was found in S/G ratio. Chemical analysis showed that the trans-genic poplar had significantly less benezene-ethanol extractive than that of control wood, but no sig-nificant differences were found in contents of ash, cold water extractive, hot water extractive, 1% NaOH extractive, holocellulose, pentosans and cellulose. Fiber assay demonstrated that down-regulation of CCoAOMTexpression improved the fiber quality in transgenic poplar. Kraft pulping showed that lower lignin in transgenic poplar led to remarkable improved pulp quality and increased pulp yield.

  10. Effects of climate factors on the height increment of poplar protection forest in the riverbank field

    Institute of Scientific and Technical Information of China (English)

    LIHai-mei; HEXing-yuan; WANGKui-ling

    2004-01-01

    Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by stepwise regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height increment of poplar protection forest and climatic factors was developed. The order of grey relevance for the effect of climatic factors on the height increment of poplar protection forest is" light>water>heat, and it could be interpreted that the poplar increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis for the intensive cultivation and regeneration of the poplar protection forest in riverbank field in similar regions in China.

  11. The use of the white poplar (Populus alba L.) biomass as fuel

    Institute of Scientific and Technical Information of China (English)

    Tatiana Griu; Aurel Lunguleasa

    2016-01-01

    We determined the calorific value of white poplar (Populus alba L.) woody biomass to use it as fire-wood. The value of 19.133 MJ kg-1 obtained experimen-tally shows that the white poplar can be quite successfully used as firewood. Being of a lower quality in comparison with usual beech firewood, the white poplar has similar calorific value. The white poplar has a calorific density of 30.7%lower than that of current firewood. That is why the price of this firewood from white poplar is lower accord-ingly. Also, the prognosis of calorific value on the basis of the main chemical elements, being very close to the experimental value (?2.6%), indicates an appropriate value can be achieved to be used for investigation with the chemical element analysis.

  12. Progress in the Study of Molecular Genetic Improvements of Poplar in China

    Institute of Scientific and Technical Information of China (English)

    Shan-Zhi Lin; Zhi-Yi Zhang; Qian Zhang; Yuan-Zhen Lin

    2006-01-01

    The poplar is one of the most economically important and intensively studied tree species owing to its wide application in the timber industry and as a model material for the study of woody plants. The natural resource of poplars in China is replete. Over the past 10 years, the application of molecular biological techniques to genetic improvements in poplar species has been widely studied in China. Recent advances in molecular genetic improvements of poplar, including cDNA library construction, gene cloning and identification, genetic engineering, gene expression, genetic linkage map construction, mapping of quantitative trait loci (QTL) and molecular-assisted selection, are reviewed in the present paper. In addition, the application of modern biotechnology to molecular improvements in the genetic traits of the poplar and some unsolved problems are discussed.

  13. Semantic coherence in English accusative-with-bare-infinitive constructions

    DEFF Research Database (Denmark)

    Jensen, Kim Ebensgaard

    2013-01-01

    Drawing on usage-based cognitively oriented construction grammar, this paper investigates the patterns of coattraction of items that appear in the two VP positions (the VP in the matrix clause, and the VP in the infinitive subordinate clause) in the English accusative-with-bare-infinitive constru......Drawing on usage-based cognitively oriented construction grammar, this paper investigates the patterns of coattraction of items that appear in the two VP positions (the VP in the matrix clause, and the VP in the infinitive subordinate clause) in the English accusative...... relations of English accusatives-with-bare-infinitives through the relations of semantic coherence between the two VPs....

  14. Imparting Barely Visible Impact Damage to a Stitched Composite Large-Scale Pressure Box

    Science.gov (United States)

    Lovejoy, Andrew E.; Przekop, Adam

    2016-01-01

    The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration, which has been a focus of the NASA Environmentally Responsible Aviation Project. The NASA-Boeing structural development for the HWB aircraft culminated in testing of the multi-bay box, which is an 80%-scale representation of the pressurized center-body section. This structure was tested in the NASA Langley Research Center Combined Loads Test System facility. As part of this testing, barely visible impact damage was imparted to the interior and exterior of the test article to demonstrate compliance with a condition representative of the requirements for Category 1 damaged composite structure as defined by the Federal Aviation Regulations. Interior impacts were imparted using an existing spring-loaded impactor, while the exterior impacts were imparted using a newly designed, gravity-driven impactor. This paper describes the impacts to the test article, and the design of the gravitydriven guided-weight impactor. The guided-weight impactor proved to be a very reliable method to impart barely visible impact damage in locations which are not easily accessible for a traditional drop-weight impactor, while at the same time having the capability to be highly configurable for use on other aircraft structures.

  15. Phospholipid bilayer formation at a bare Si surface

    DEFF Research Database (Denmark)

    Gutberlet, T.; Steitz, R.; Fragneto, G.

    2004-01-01

    Neutron reflectivity was applied to monitor in situ the adsorption of small unilamellar phospholipid vesicles on a solid bare hydrophilic Si interface. The obtained reflectivity curves are consistent with the rupture and fusion model for the adsorption of phosphatidylcholine vesicles to solid...

  16. Het paracervicale block tijdens de baring

    NARCIS (Netherlands)

    P.K. Flu (Peter Kalev)

    1977-01-01

    textabstractDe baring is het enige fysiologische gebeuren dat met pijn gepaard gaat. Dit wordt reeds aangeduid door het Nederlandse woord 11wee" en equivalente woorden in vele andere talen (dolor, douleur, pains, Wehe e.a.). De pijn is aanvankelijk vooral gelocaliseerd in de onderbuik en onder in de

  17. BARE retrotransposons are translated and replicated via distinct RNA pools.

    Directory of Open Access Journals (Sweden)

    Wei Chang

    Full Text Available The replication of Long Terminal Repeat (LTR retrotransposons, which can constitute over 80% of higher plant genomes, resembles that of retroviruses. A major question for retrotransposons and retroviruses is how the two conflicting roles of their transcripts, in translation and reverse transcription, are balanced. Here, we show that the BARE retrotransposon, despite its organization into just one open reading frame, produces three distinct classes of transcripts. One is capped, polyadenylated, and translated, but cannot be copied into cDNA. The second is not capped or polyadenylated, but is destined for packaging and ultimate reverse transcription. The third class is capped, polyadenylated, and spliced to favor production of a subgenomic RNA encoding only Gag, the protein forming virus-like particles. Moreover, the BARE2 subfamily, which cannot synthesize Gag and is parasitic on BARE1, does not produce the spliced sub-genomic RNA for translation but does make the replication competent transcripts, which are packaged into BARE1 particles. To our knowledge, this is first demonstration of distinct RNA pools for translation and transcription for any retrotransposon.

  18. Basic science of nuclear medicine the bare bone essentials

    CERN Document Server

    Lee, Kai H

    2015-01-01

    Through concise, straightforward explanations and supporting graphics that bring abstract concepts to life, the new Basic Science of Nuclear Medicine—the Bare Bone Essentials is an ideal tool for nuclear medicine technologist students and nuclear cardiology fellows looking for an introduction to the fundamentals of the physics and technologies of modern day nuclear medicine.

  19. Comparative Physiological and Proteomic Analysis Reveals the Leaf Response to Cadmium-Induced Stress in Poplar (Populus yunnanensis.

    Directory of Open Access Journals (Sweden)

    Yunqiang Yang

    Full Text Available Excess amounts of heavy metals are important environmental pollutants with significant ecological and nutritional effects. Cdmium (Cd is of particular concern because of its widespread occurrence and high toxicity. We conducted physiological and proteomic analyses to improve our understanding of the responses of Populus yunnanensis to Cd stress. The plantlets experienced two apparent stages in their response to Cd stress. During the first stage, transiently induced defense-response molecules, photosynthesis- and energy-associated proteins, antioxidant enzymes and heat shock proteins (HSPs accumulated to enhance protein stability and establish a new cellular homeostasis. This activity explains why plant photosynthetic capability during this period barely changed. During the second stage, a decline of ribulose-1, 5-bisphosphate carboxylase (RuBisCO and HSP levels led to imbalance of the plant photosynthetic system. Additionally, the expression of Mitogen-activated protein kinase 3 (MPK3, Mitogen-activated protein kinase 6 (MPK6 and a homeobox-leucine zipper protein was higher in the second stage. Higher expression of caffeoyl-CoA O-methyltransferase (CCoAOMT may regulate plant cell wall synthesis for greater Cd storage. These genes may be candidates for further research and use in genetic manipulation of poplar tolerance to Cd stress.

  20. Wood Properties of Poplar from Stand Affected by Acid Rain

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Wood properties from 28 trees (Populus euramericana) selected from healthy and acid rain damaged forest were measured to evaluate the possible impacts on wood quality and utilization. On the heavily damaged location, the pH value of precipitation ranged from 3.7-5.0, and sulfate loading ranged from 20-40 kg·ha-2.y-1. Quantitative and qualitative studies on ring width, physical properties and mechanical properties indicated that changes of wood properties between diseased and healthy poplar occurred. Aci...

  1. Greenhouse gas balance of cropland conversion to bioenergy poplar short rotation coppice

    Science.gov (United States)

    Sabbatini, S.; Arriga, N.; Bertolini, T.; Castaldi, S.; Chiti, T.; Consalvo, C.; Njakou Djomo, S.; Gioli, B.; Matteucci, G.; Papale, D.

    2015-05-01

    The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. Soil organic carbon (SOC) of an older poplar plantation was used to estimate via a regression the SOC loss due to SRC establishment. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled and GHG emission offset due to fossil fuel substitution was credited to the SRC site considering the C intensity of natural gas. Emissions due to the use of the biomass (FEXP) were also considered. The suitability was finally assessed comparing the GHG budgets of the two sites. FCO2 was the higher flux in the SRC site (-3512 ± 224 g CO2 eq m-2 in two years), while in the REF site it was -1838 ± 107 g CO2 m-2 in two years. FEXP was equal to 1858 ± 240 g CO2 m-2 in 24 months in the REF site, thus basically compensating FCO2, while it was 1118 ± 521 g CO2 eq m-2 in 24 months in the SRC site. This latter could offset -379.7 ± 175.1 g CO2 eq m-2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN weighed 2 and 4% in the GHG budgets of SRC and REF sites respectively, while the SOC loss weighed 455 ± 524 g CO2 m-2 in two years. Overall, the REF site was close to neutrality in a GHG perspective (156 ± 264 g CO2 eq m-2), while the SRC site was a net sink of -2202 ± 792 g CO2 eq m-2. In conclusion the experiment led to a positive evaluation of the conversion of cropland to bioenergy SRC from a GHG viewpoint.

  2. Effect of drought on fine roots productivity in poplar-based short rotation coppice

    Science.gov (United States)

    Mani Tripathi, Abhishek; Fischer, Milan; Berhongaray, Gonzalo; Orság, Matěj; Trnka, Miroslav

    2015-04-01

    Short rotation woody crops (SRWC) are alternative source of bioenergy, which apart from their 'carbon neutrality' have potential to store carbon (C) into soil and mitigate the increasing CO2 emission. Studies of below ground biomass of trees are divided into two types according to root diameter - analysis of fine roots (less than 2 mm) and coarse roots (more than 2 mm). Trees roots are spatially highly heterogeneous and it requires large number of samples to obtain a representative estimate of belowground biomass. For this study we used hybrid poplar clone J-105 (Populus nigra x P. maximowiczii) grown under short rotation coppice system in the region of Bohemian-Moravian Highland (49o32'N, 16o15'E and altitude 530 m a.s.l.) since April 2000. The plantation with planting density of 9,216 trees ha-1 was established on the former agricultural land and the length of the rotation cycle was set to 6-8 years. While mean annual rainfall was 609 mm with mean annual temperature 7.2oC during 1981-2013 significant increase of temperature and more frequent droughts are expected. In 2011, we established drought experiment based on throughfall exclusion system, reducing up to 70 % of throughfall precipitation. Thus 2 treatments with normal and lowered soil moisture levels were introduced. In January and February 2014, we cored 18 places including drought and control using root bipartite auger. The main goal of the study is to assess the response of fine roots productivity and fine roots vertical distribution on the reduced soil water availability. Results will be presented at the conference. Acknowledgements: This study was funded by research project IGA Mendel University 2014 "Study of below ground biomass in short rotation poplar coppice (J-105) in the Czech-Moravian Highlands", project PASED (KONTAKT II LH12037 ʺDevelopment of models for the assessment of abiotic stresses in selected energy woody plantsʺ and "Building up a multidisciplinary scientific team focused on drought

  3. Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice

    Science.gov (United States)

    Sabbatini, S.; Arriga, N.; Bertolini, T.; Castaldi, S.; Chiti, T.; Consalvo, C.; Njakou Djomo, S.; Gioli, B.; Matteucci, G.; Papale, D.

    2016-01-01

    The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short-rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. This period corresponded to a single rotation of the SRC site. The REF site was a crop rotation between grassland and winter wheat, i.e. the same management of the SRC site before the conversion to short-rotation coppice. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. The measurements began 2 years after the conversion of arable land to SRC so that an older poplar plantation was used to estimate the soil organic carbon (SOC) loss due to SRC establishment and to estimate SOC recovery over time. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled. A GHG emission offset, due to the substitution of natural gas with SRC biomass, was credited to the GHG budget of the SRC site. Emissions generated by the use of biomass (FEXP) were also considered. Suitability was finally assessed by comparing the GHG budgets of the two sites. CO2 uptake was 3512 ± 224 g CO2 m-2 at the SRC site in 2 years, and 1838 ± 107 g CO2 m-2 at the REF site. FEXP was equal to 1858 ± 240 g CO2 m-2 at the REF site, thus basically compensating for FCO2, while it was 1118 ± 521 g CO2 m-2 at the SRC site. The SRC site could offset 379.7 ± 175.1 g CO2eq m-2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN made up 2 and 4 % in the GHG budgets of SRC and REF sites respectively, while the SOC loss was 455 ± 524 g CO2 m-2 in 2 years. Overall, the REF site was close to neutrality from a GHG perspective (156 ± 264 g CO2eq m-2), while the SRC site was a net sink of

  4. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral "Salicoid" Genome Duplication.

    Science.gov (United States)

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-06-27

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the "salicoid" duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants.

  5. Enhancement of Biogas Yield of Poplar Leaf by High-Solid Codigestion with Swine Manure.

    Science.gov (United States)

    Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

    2016-05-01

    The aim of this work was to examine the improvement of anaerobic biodegradability of organic fractions of poplar leaf from codigestion with swine manure (SM), thus biogas yield and energy recovery. When poplar leaf was used as a sole substrate, the cumulative biogas yield was low, about 163 mL (g volatile solid (VS))(-1) after 45 days of digestion with a substrate/inoculum ratio of 2.5 and a total solid (TS) of 22 %. Under the same condition, the cumulative biogas yield of poplar leaf reached 321 mL (g VS)(-1) when SM/poplar leaf ratio was 2:5 (based on VS). The SM/poplar leaf ratio can determine C/N ratio of the cosubstrate and thus has significant influence on biogas yield. When the SM/poplar leaf ratio was 2:5, C/N ratio was calculated to be 27.02, and the biogas yield in 45 days of digestion was the highest. The semi-continuous digestion of poplar leaf was carried out with the organic loading rate of 1.25 and 1.88 g VS day(-1). The average daily biogas yield was 230.2 mL (g VS)(-1) and 208.4 mL (g VS)(-1). The composition analysis revealed that cellulose and hemicellulose contributed to the biogas production.

  6. Phytoextraction of risk elements by willow and poplar trees.

    Science.gov (United States)

    Kacálková, Lada; Tlustoš, Pavel; Száková, Jiřina

    2015-01-01

    To characterize the phytoextraction efficiency of two clones of willow trees (Salix x smithiana Willd., Salix rubens) and two clones of poplar trees (Populus nigra x maximowiczii, Populus nigra Wolterson) were planted in contaminated soil (0.4-2.0 mg Cd.kg(-1), 78-313 mg Zn.kg(-1), 21.3-118 mg Cu.kg(-1)). Field experiment was carried out in Czech Republic. The study investigated their ability to accumulate heavy metals (Cd, Zn, and Cu) in harvestable plant parts. The poplars produced higher amount of biomass than willows. Both Salix clones accumulated higher amount of Cd, Zn and Cu in their biomass (maximum 6.8 mg Cd.kg(-1), 909 mg Zn.kg(-1), and 17.7 mg Cu.kg(-1)) compared to Populus clones (maximum 2.06 mg Cd.kg(-1), 463 mg Zn.kg(-1), and 11.8 mg Cu.kg(-1)). There were no significant differences between clones of individual species. BCs for Cd and Zn were greater than 1 (the highest in willow leaves). BCs values of Cu were very low. These results indicate that Salix is more suitable plant for phytoextraction of Cd and Zn than Populus. The Cu phytoextraction potential of Salix and Populus trees was not confirmed in this experiment due to low soil availability of this element.

  7. Enhancement of Enzymatic Saccharification of Poplar by Green Liquor Pretreatment

    Directory of Open Access Journals (Sweden)

    Xin Meng

    2014-04-01

    Full Text Available Green liquor (Na2S + Na2CO3, GL pretreatment is an effective pathway for improving the enzymatic digestibility of lignocellulosic biomass for the production of bioethanol. In this work, GL was employed as a pretreatment to enhance the enzymatic saccharification of poplar. During pretreatment, the increase of H-factor and TTA charge resulted in enhanced delignification and increased degradation of polysaccharides. The sugar yield of enzymatic hydrolysis increased rapidly with increasing TTA charge in GL pretreatment, while the effect of different H-factors (from 400 to 800 on sugar yield was unnoticeable. The pretreated solid recovery was 75.5% at a lignin removal rate of 29.2% under optimized conditions of total titratable alkali (TTA charge 20%, sulfidity 25%, and H-factor 400. The sugar yield of glucan, xylan, and total sugar of GL-pretreated poplar in enzymatic hydrolysis reached up to 89.9%, 65.5%, and 82.8%, respectively, at a cellulase loading of 40 FPU/g-cellulose.

  8. Soils organic C sequestration under poplar and willow agroforestry systems

    Science.gov (United States)

    Gunina, Anna; Tariq, Azeem; Lamersdorf, Norbert

    2015-04-01

    Short rotation coppices (SRC) as monocultures or as agroforestry (AF) applications (e.g. alley cropping) are two techniques to implement forest into agricultural practices. Despite afforestation promotes soil carbon (C) accumulation, age and type of the tree stand can affect the C accumulation in different degrees. Here, we studied the impact of afforestation on C accumulation for: i) pure SCR of willow (Salix viminalis x Salix schwerinii) and poplar (Populus nigra x Populus maximowiczii) and ii) AF cropping system with willow. Forest systems have been established within the BEST agroforestry project in Germany. Adjacent agricultural field have been used as a control. Soil samples were collected in 2014, three years after plantation establishment, from three soil depths: 0-3, 3-20, and 20-30 cm. Total organic C, labile C (incubation of 20 g soil during 100 days with measuring of CO2) and aggregate structure were analysed. Additionally, density fractionation of the samples from 0-3 cm was applied to separate particulate organic matter (POM) and mineral fractions. Aggregates and density fractions were analyzed for C content. High input of plant litter as well as root exudates have led to increases of organic C in AF and SRC plots compare to cropland, mainly in the top 0-3 cm. The highest C content was found for willow SRC (18.2 g kg-1 soil), followed by willow-AF (15.6 g kg-1 soil), and poplar SRC (13.7 g kg-1 soil). Carbon content of cropland was 12.5 g kg-1 soil. Absence of ploughing caused increase portion of macroaggregates (>2000 μm) under SRC and AF in all soil layers as well as the highest percentage of C in that aggregate size class (70-80%). In contrast, C in cropland soil was mainly accumulated in small macroaggregates (250-2000 μm). Intensive mineralisation of fresh litter and old POM, taking place during first years of trees development, resulted to similar portions of free POM for willow AF, willow SRC and cropland (8%), and even lower ones for poplar

  9. Assembling Bare Au Nanoparticles at Positively Charged Templates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

    2016-05-26

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the chargedinterfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits shortrange in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), display less in-plane regular packing compared to bare AuNPs.

  10. Low cost bare-plate solar air collector

    Energy Technology Data Exchange (ETDEWEB)

    Maag, W.L.; Wenzler, C.J.; Rom, F.E.; VanArsdale, D.R.

    1980-09-01

    The purpose of this project was to develop a low cost, bare-plate collector, determine its performance for a variety of climatic conditions, analyze the economics of this type of solar collector and evaluate specific applications. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60% or greater with air preheat temperature uses up to 20/sup 0/F for one of the prototypes. The economic analyses indicated that an installed cost of between $5 and $10 per square foot would make this type of solar system economically viable. For the materials of construction and the type of fabrication and installation perceived, these costs for the bare-plate solar collector are believed to be attainable. Specific applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

  11. Terrain classification of ladar data for bare earth determination

    Science.gov (United States)

    Neuenschwander, Amy L.; Magruder, Lori A.

    2011-06-01

    Terrain classification, or bare earth extraction, is an important component to LADAR data analysis. The terrain classification approach presented in this effort utilizes an adaptive lower envelope follower (ALEF) with an adaptive gradient operation for accommodations of local topography and roughness. In order to create a more robust capability, the ALEF was modified to become a strictly data driven process that facilitates a quick production of the data product without the subjective component associated with user inputs. This automated technique was tested on existing LADAR surveys over Wyoming's Powder River Basin and the John Starr Memorial Forest in Mississippi, both locations with dynamic topographic features. The results indicate a useful approach in terms of operational time and accuracy of the final bare earth recovery with the advantage of being fully data driven.

  12. Assembling Bare Au Nanoparticles at Positively Charged Templates

    Science.gov (United States)

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

    2016-05-01

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), display less in-plane regular packing compared to bare AuNPs.

  13. UAV-Based Thermal Imaging for High-Throughput Field Phenotyping of Black Poplar Response to Drought

    Directory of Open Access Journals (Sweden)

    Riccardo Ludovisi

    2017-09-01

    Full Text Available Poplars are fast-growing, high-yielding forest tree species, whose cultivation as second-generation biofuel crops is of increasing interest and can efficiently meet emission reduction goals. Yet, breeding elite poplar trees for drought resistance remains a major challenge. Worldwide breeding programs are largely focused on intra/interspecific hybridization, whereby Populus nigra L. is a fundamental parental pool. While high-throughput genotyping has resulted in unprecedented capabilities to rapidly decode complex genetic architecture of plant stress resistance, linking genomics to phenomics is hindered by technically challenging phenotyping. Relying on unmanned aerial vehicle (UAV-based remote sensing and imaging techniques, high-throughput field phenotyping (HTFP aims at enabling highly precise and efficient, non-destructive screening of genotype performance in large populations. To efficiently support forest-tree breeding programs, ground-truthing observations should be complemented with standardized HTFP. In this study, we develop a high-resolution (leaf level HTFP approach to investigate the response to drought of a full-sib F2 partially inbred population (termed here ‘POP6’, whose F1 was obtained from an intraspecific P. nigra controlled cross between genotypes with highly divergent phenotypes. We assessed the effects of two water treatments (well-watered and moderate drought on a population of 4603 trees (503 genotypes hosted in two adjacent experimental plots (1.67 ha by conducting low-elevation (25 m flights with an aerial drone and capturing 7836 thermal infrared (TIR images. TIR images were undistorted, georeferenced, and orthorectified to obtain radiometric mosaics. Canopy temperature (Tc was extracted using two independent semi-automated segmentation techniques, eCognition- and Matlab-based, to avoid the mixed-pixel problem. Overall, results showed that the UAV platform-based thermal imaging enables to effectively assess genotype

  14. Nuda vida y goce. // Bare life and jouissance.

    OpenAIRE

    Laura Arias.

    2010-01-01

    From the point of view that connects politics and psychoanalysis, the aim of this essay is to investigate the causes of the annihilation of the subject in the totalitarian regimes, making him a victim of power, reduced to a bare life. This question leads us to analyze the jouissance within the frame of a regime that proposes the unification of a universal jouissance. These questions are considered to be relevant in the field that makes possible the intersection between politics and subjectivi...

  15. The Political Animal: Species-Being and Bare Life

    Directory of Open Access Journals (Sweden)

    Laura Hudson

    2008-01-01

    Full Text Available Marxism has been justifiably skeptical of animal rights. Indeed, deep ecology and animal-rights discourse are, in their native habitats, deeply problematic and self-contradictory. But recent theories of “bare life,” when brought into dialogue with Marx’s concept of species-being, offer a perspective from which animal rights discourse and Marxism share a common political horizon.

  16. Evaluation of Lower East Fork Poplar Creek Mercury Sources

    Energy Technology Data Exchange (ETDEWEB)

    Watson, David B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brooks, Scott C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mathews, Teresa J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevelhimer, Mark S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DeRolph, Chris [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ketelle, Richard [East Tennessee Technology Park (ETTP), Oak Ridge, TN (United States)

    2016-06-01

    This report summarizes a 3-year research project undertaken to better understand the nature and magnitude of mercury (Hg) fluxes in East Fork Poplar Creek (EFPC). This project addresses the requirements of Action Plan 1 in the 2011 Oak Ridge Reservation-wide Comprehensive Environmental Response, Compensation, and Liability Act Five Year Review (FYR). The Action Plan is designed to address a twofold 2011 FYR issue: (1) new information suggests mobilization of mercury from the upper and lower EFPC streambeds and stream banks is the primary source of mercury export during high-flow conditions, and (2) the current Record of Decision did not address the entire hydrologic system and creek bank or creek bed sediments. To obtain a more robust watershed-scale understanding of mercury sources and processes in lower EFPC (LEFPC), new field and laboratory studies were coupled with existing data from multiple US Department of Energy programs to develop a dynamic watershed and bioaccumulation model. LEFPC field studies for the project focused primarily on quantification of streambank erosion and an evaluation of mercury dynamics in shallow groundwater adjacent to LEFPC and potential connection to the surface water. The approach to the stream bank study was innovative in using imagery from kayak floats’ surveys from the headwaters to the mouth of EFPC to estimate erosion, coupled with detailed bank soil mercury analyses. The goal of new field assessments and modeling was to generate a more holistic and quantitative understanding of the watershed and the sources, flux, concentration, transformation, and bioaccumulation of inorganic mercury (IHg) and methylmercury (MeHg). Model development used a hybrid approach that dynamically linked a spreadsheet-based physical and chemical watershed model to a systems dynamics, mercury bioaccumulation model for key fish species. The watershed model tracks total Hg and MeHg fluxes and concentrations by examining upstream inputs, floodplain

  17. Bare-Hand Volume Cracker for Raw Volume Data Analysis

    Directory of Open Access Journals (Sweden)

    Bireswar Laha

    2016-09-01

    Full Text Available Analysis of raw volume data generated from different scanning technologies faces a variety of challenges, related to search, pattern recognition, spatial understanding, quantitative estimation, and shape description. In a previous study, we found that the Volume Cracker (VC 3D interaction (3DI technique mitigated some of these problems, but this result was from a tethered glove-based system with users analyzing simulated data. Here, we redesigned the VC by using untethered bare-hand interaction with real volume datasets, with a broader aim of adoption of this technique in research labs. We developed symmetric and asymmetric interfaces for the Bare-Hand Volume Cracker (BHVC through design iterations with a biomechanics scientist. We evaluated our asymmetric BHVC technique against standard 2D and widely used 3D interaction techniques with experts analyzing scanned beetle datasets. We found that our BHVC design significantly outperformed the other two techniques. This study contributes a practical 3DI design for scientists, documents lessons learned while redesigning for bare-hand trackers, and provides evidence suggesting that 3D interaction could improve volume data analysis for a variety of visual analysis tasks. Our contribution is in the realm of 3D user interfaces tightly integrated with visualization, for improving the effectiveness of visual analysis of volume datasets. Based on our experience, we also provide some insights into hardware-agnostic principles for design of effective interaction techniques.

  18. Histone Acetylation Modifications Affect Tissue-Dependent Expression of Poplar Homologs of C4 Photosynthetic Enzyme Genes

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2017-06-01

    Full Text Available Histone modifications play important roles in regulating the expression of C4 photosynthetic genes. Given that all enzymes required for the C4 photosynthesis pathway are present in C3 plants, it has been hypothesized that this expression regulatory mechanism has been conserved. However, the relationship between histone modification and the expression of homologs of C4 photosynthetic enzyme genes has not been well determined in C3 plants. In the present study, we cloned nine hybrid poplar (Populus simonii × Populus nigra homologs of maize (Zea mays C4 photosynthetic enzyme genes, carbonic anhydrase (CA, pyruvate orthophosphate dikinase (PPDK, phosphoenolpyruvate carboxykinase (PCK, and phosphoenolpyruvate carboxylase (PEPC, and investigated the correlation between the expression levels of these genes and the levels of promoter histone acetylation modifications in four vegetative tissues. We found that poplar homologs of C4 homologous genes had tissue-dependent expression patterns that were mostly well-correlated with the level of histone acetylation modification (H3K9ac and H4K5ac determined by chromatin immunoprecipitation assays. Treatment with the histone deacetylase inhibitor trichostatin A further confirmed the role of histone acetylation in the regulation of the nine target genes. Collectively, these results suggest that both H3K9ac and H4K5ac positively regulate the tissue-dependent expression pattern of the PsnCAs, PsnPPDKs, PsnPCKs, and PsnPEPCs genes and that this regulatory mechanism seems to be conserved among the C3 and C4 species. Our findings provide new insight that will aid efforts to modify the expression pattern of these homologs of C4 genes to engineer C4 plants from C3 plants.

  19. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

    Directory of Open Access Journals (Sweden)

    Richard S. Winder

    2013-09-01

    Full Text Available The impacts of leaf litter from genetically-modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β–Proteobacteria were proportionally more numerous at high tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051. Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA partitioned the fungal communities into three groups: (i those with higher amounts of added tannin from both transformed and untransformed treatments, (ii those corresponding to soils without litter, and (iii those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase (GUS control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in tannin levels.

  20. Wettability of poplar leaves influences dew formation and infection by Melampsora larici-populina

    National Research Council Canada - National Science Library

    Pinon, Jean; Frey, Pascal; Husson, Claude

    2006-01-01

    .... The frequency and duration of dew on these clones were recorded in two nurseries. Black poplar leaves had the highest wettability, with relatively flat-shaped water droplets and a short drying time, in both the laboratory and nursery...

  1. Response of ecosystem carbon fluxes to drought events in a poplar plantation in Northern China

    Science.gov (United States)

    Jie Zhou; Zhiqiang Zhang; Ge Sun; Xianrui Fang; Tonggang Zha; Steve McNulty; Jiquan Chen; Ying Jin; Asko Noormets

    2013-01-01

    Poplar plantations are widely used for timber production and ecological restoration in northern China,a region that experiences frequent droughts and water scarcity. An open-path eddy-covariance (EC)system was used to continuously measure the carbon,water,and energy fluxes in a poplar plantation during the growing season (i.e., April–October)over the period 2006–2008...

  2. Evaluation of soil nutrient status in poplar forest soil by soil nutrient systematic approach

    Institute of Scientific and Technical Information of China (English)

    YUChang-bing; CHENFang; LUOZhi-jian; CHENWei-wen

    2004-01-01

    A study was conducted to evaluate the soil nutrient status of poplar plantation by Soil Nutrient Systematic Approach(SNSA) in Jianghan Plain, Hubei Province, China. Soil physiochemical properties were analyzed in laboratory through collection soil samples of study site. Ten treatments of application different fertilizers were designed such as CK, optimum treatment (N, P,K, Zn), -N(P, K, Zn), -P(N, K, Zn), -K(N, P, Zn), +Mg(N, P, K, Zn, Mg), -Zn (N,P,K), +2P(N, 2P, K, Zn), +2K(N, P, 2K, Zn), and 2N+2P+2K(2N, 2P, 2K, Zn) for field experiment to test the effect on tree height, diameter (DBH) growth, and dry weight of poplar.The results showed that there was no significant difference in tree heights between treatments with different fertilizers, diameter growth of poplar trees in treatments of lack of N and Zn was significantly slower than that of trees in optimum treatment, and dry weight of poplar dropped significantly for treatment of CK as well as treatments without application N and Zn. It is concluded that N and Zn were main limiting factor for poplar growth. Results from laboratory analysis and field experiment were uniform perfectly, which proved that SNSA was reliable in evaluating soil nutrient status of poplar plantation.

  3. Feasibility of poplar foliages as bio-monitors for organochlorine pesticides in air

    Institute of Scientific and Technical Information of China (English)

    DAI TianYou; ZHU XiaoHua; WANG Wei; MENG Wei; YU YunJiang; LI FaSheng; YANG YongLiang; LIU Feng

    2009-01-01

    The feasibility of poplar (P. tomentosa) foliages as passive biomonitors for organochlorine pesticides In air was explored. The accumulation patterns of poplar foliages for HCHs, DDTs and HCB were similar, the amount of HCHs, DDTs and HCB increased with foliage growth in spring, and decreased thereafter. There was no obvious distinction in the accumulation styles between the adult leaf and the leaf-litter. This accumulation pattern is likely related to the growing process of the poplar foliage, and was ob-served for the first time in our work, giving an evidence for the "bud burst effect" in plants. The tech-nical HCH and DDT were used largely in history and not used in recent years, but there was a little usage of lindane and new input of o,p'DDT in recent years, and dicofol usage may be the main source of o,p'-DDT. Concentrations of HCHs, DDTs and HCB in poplar foliages were similar to those in pine needles at the corresponding period, and there is a positive strong correlation between OCP concen-tration data of two kinds of trees. It presents no difference in the accumulation style between two kinds of trees. The level of OCPs in the poplar foliage reflected the pollution status of OCPs in air. The result of this work showed that the poplar foliage can be used as the bio-monitor of OCPs in air.

  4. Dechlorination of PCBs in the rhizosphere of switchgrass and poplar.

    Science.gov (United States)

    Meggo, Richard E; Schnoor, Jerald L; Hu, Dingfei

    2013-07-01

    Polychlorinated biphenyl (PCB) congeners (PCB 52, 77, and 153) singly and in mixture were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks. There was evidence of reductive dechlorination in both planted and unplanted systems, but the planted microcosms with fully developed roots and rhizospheres showed greater biotransformation than the unplanted reactors. These dechlorination products accounted for approximately all of the molar mass of parent compound lost. Based on the transformation products, reductive dechlorination pathways are proposed for rhizospheric biotransformation of PCB 52, 77, and 153. This is the first report of rhizosphere biotransformation pathways for reductive dechlorination in marginally aerobic, intermittently flooded soil as evidenced by a mass balance on transformation products.

  5. Wood Microstructure Effects on Chinese White Poplar Dyeing

    Institute of Scientific and Technical Information of China (English)

    DUANXinfang; BAOFucheng

    2004-01-01

    In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tornentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures,and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6-0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese whitep oplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.

  6. Quantification of carbon sources for isoprene emission in poplar leaves

    Science.gov (United States)

    Kreutzwieseer, J.; Graus, M.; Schnitzler, J. P.; Heizmann, U.; Rennenberg, H.; Hansel, A.

    2003-12-01

    Isoprene is the most abundant volatile organic compound emitted by plants and in particular by trees. Current interest in understanding its biosynthesis in chloroplasts is forced by the important role isoprene plays in atmospheric chemistry. Leaf isoprene formation is closely linked to photosynthesis by a dynamic use of recently fixed photosynthetic precursors in the chloroplast. Under steady state conditions in [13C]CO2 atmosphere approximately 75 % of isoprene became labeled within minutes. The source of unlabeled C is suggested to be of extra-chloroplastidic and/or from starch degradation. In order to test whether these alternative carbon sources - leaf internal C-pools and xylem-transported carbohydrates, contribute to leaf isoprene formation in poplar (Populus tremula x P. alba) on-line proton-transfer-reaction-mass spectrometry (PTR-MS) was used to follow 13C-labeling kinetics.

  7. Lead Tolerance and Accumulation in White Poplar Cultivated In Vitro

    Directory of Open Access Journals (Sweden)

    Branislav Kovačević

    2013-06-01

    Full Text Available Background and Purpose: This paper analyses the lead tolerance and accumulation in white poplar genotypes in vitro, in order to optimize genotype evaluation and other procedures in their implementation in phytoremediation projects and landscaping in areas endangered by lead accumulation. Material and Methods: The lead tolerance and accumulation of five white poplar genotypes after 35 days in vitro cultivation on media supplemented with lead was examined. The following Pb(NO32 concentrations were used: 0, 10-6, 10-5, 10-4 and 10-3 M. Tolerance analysis (described by tolerance indices was based on morphological parameters, biomass accumulation and the content of photosynthetic pigments, while lead accumulation was described by shoot lead accumulation and shoot lead content. Results and Conclusions: The chosen lead concentrations appeared not to be lethal. Moreover, the obtained results showed that the tested lead concentrations had a positive effect on: number of formed roots, shoot moisture content and shoot height. The best differentiation among the examined genotypes was gained by the tolerance index based on the shoot height on 10-4 M Pb(NO32. The shoot lead accumulation and shoot lead content significantly increased on 10-4 and 10-3 M Pb(NO32 media. Thus, the concentration of 10-4 M Pb(NO32 is recommended for further research. Two examined genotypes of horticultural value (LCM and LBM achieved a significantly higher lead shoot content compared to the wide spread genotype “Villafranca” (almost 200% and 125% higher, respectively.

  8. 30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

  9. 30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

  10. 30 CFR 77.515 - Bare signal or control wires; voltage.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

  11. Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984 - April 1, 1985

    Science.gov (United States)

    Smalley, R. E.

    1985-01-01

    There have been four major areas of concentration for the study of bare metal cluster beams: neutral cluster, chemical reactivity, cold cluster ion source development (both positive and negative), bare cluster ion ICR (ion cyclotron resonance) development, and photofragmentation studies of bare metal cluster ions.

  12. 30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Plans for insulation of existing bare power... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to...

  13. Wave energy resource in the Estaca de Bares area (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, G.; Carballo, R. [Univ. of Santiago de Compostela, EPS, Hydraulic Eng., Campus Univ. s/n, 27002 Lugo (Spain)

    2010-07-15

    The area around Cape Estaca de Bares (the northernmost point of Iberia) presents a great potential for wave energy exploitation owing to its prominent position, with average deepwater wave power values exceeding 40 kW/m. The newly available SIMAR-44 dataset, composed of hindcast data spanning 44 years (1958-2001), is used alongside wave buoy data and numerical modelling to assess this substantial energy resource in detail. Most of the energy is provided by waves from the IV quadrant, generated by the prevailing westerlies blowing over the long Atlantic fetch. Combined scatter and energy diagrams are used to characterise the wave energy available in an average year in terms of the sea states involved. The lion's share is shown to correspond to significant wave heights between 2 and 5 m and energy periods between 11 and 14 s. The nearshore energy patterns are then examined using a coastal wave model (SWAN) with reference to four situations: average wave energy, growing wave energy (at the approach of a storm), extreme wave energy (at the peak of the storm) and decaying wave energy (as the storm recedes). The irregular bathymetry is found to produce local concentrations of wave energy in the nearshore between Cape Prior and Cape Ortegal and in front of Cape Estaca de Bares, with similar patterns (but varying wave power) in the four cases. These nearshore areas of enhanced wave energy are of the highest interest as prospective sites for a wave energy operation. The largest of them is directly in the lee of a large underwater mount west of Cape Ortegal. In sum, the Estaca de Bares area emerges as one of the most promising for wave energy exploitation in Europe. (author)

  14. Rethinking biopower: posthumanism, bare life, and emancipatory work.

    Science.gov (United States)

    Cloyes, Kristin G

    2010-01-01

    This article answers a call, recently published in Advances in Nursing Science, to more fully explore the use of Italian political philosopher Giorgio Agamben's theory of biopower in nursing research and scholarship. Giorgio Agamben argues that biopower is not a modern phenomenon, and critical analysis of the historical origins of Western political practice shows how humanist discourse has been complicit in a long tradition of marginalization and violence, accomplished in each era by designating certain classes of human beings as "bare life." I discuss how I have used Agamben's theory to frame my own research, and the challenges of applying this theory in emancipatory work.

  15. Phospholipid bilayer formation at a bare Si surface

    DEFF Research Database (Denmark)

    Gutberlet, T.; Steitz, R.; Fragneto, G.;

    2004-01-01

    Neutron reflectivity was applied to monitor in situ the adsorption of small unilamellar phospholipid vesicles on a solid bare hydrophilic Si interface. The obtained reflectivity curves are consistent with the rupture and fusion model for the adsorption of phosphatidylcholine vesicles to solid...... interfaces. The results show details of the adsorbed bilayer system at ångström resolution and indicate the presence of a thin ∼6 Å thick water leaflet that separates the bilayer from the Si surface. The resolved structural details provide the basis for further investigation of processes such as adsorption...

  16. Evaporation Dynamics of Moss and Bare Soil in Boreal Forests

    Science.gov (United States)

    Dempster, S.; Young, J. M.; Barron, C. G.; Bolton, W. R.

    2013-12-01

    Evaporation dynamics of mosses is a critical process in boreal and arctic systems and represents a key uncertainty in hydrology and climate models. At this point, moss evaporation is not well quantified at the plot or landscape scale. Relative to bare soil or litter evaporation, moss evaporation can be challenging to predict because the water flux is not isolated to the moss surface. Evaporation can originate from nearly 10 cm below the surface. Some mosses can wick moisture from even deeper than 10 cm, which subsequently evaporates. The goal of this study was to use field measurements to quantify the moss evaporation dynamics in a coniferous forest relative to bare ground or litter evaporation dynamics in a deciduous forest in Interior Alaska. Measurements were made in two ecosystem types within the boreal forest of Interior Alaska: a deciduous forest devoid of moss and a coniferous forest with a thick moss layer. A small clear chamber was attached to a LiCor 840 infrared gas analyzer in a closed loop system with a low flow rate. Water fluxes were measured for ~ 90 seconds on each plot in dry and wet soil and moss conditions. Additional measurements included: soil temperature, soil moisture, air temperature, barometric pressure, dew point, relative humidity, and wind speed. Thermal infrared images were also captured in congruence with water flux measurements to determine skin temperature. We found that the moss evaporation rate was over 100% greater than the soil evaporation rate (0.057 g/min vs. 0.024 g/min), and evaporation rates in both systems were most strongly driven by relative humidity and surface temperature. Surface temperature was lower at the birch site than the black spruce site because trees shade the surface beneath the birch. High fluxes associated with high water content were sustained for a longer period of time over the mosses compared to the bare soil. The thermal IR data showed that skin temperature lagged the evaporation flux, such that the

  17. Isolation and analysis of a TIR-specific promoter from poplar

    Institute of Scientific and Technical Information of China (English)

    Zheng Hui-quan; Lin Shan-zhi; Zhang Qian; Zhang Zhen-zhen; Zhang Zhi-yi; Lei Yang; Hou Lu

    2007-01-01

    A 5'flanking region of the well-conserved Toll/interleukin-1 receptor domain (TIR)-encoding sequence was isolated from the genomic DNA of Melampsora magnusiana Wagner resistant clones of hybrid triploid poplars [(Populus tomentosa × P. bolleana)× P. tomentosa]. Sequencing results and alignment analysis show that the obtained TIR-specific promoter (named as PtTIRp01) was 1,732 bp in length; moreover 3'region of the PtTIRp01 contains a 398 bp complete TIR-encoding sequence, which significantly corresponds to the 5'composition of TIR-NBS type gene PtDRG02, indicating that the obtained TIR-specific promoter region consists of 747 bp long 5'region of TIR-NBS type gene PtDRG02 and its upstream region of promoter (985 bp). It was found that the 5'region of TIR-NBS type gene PtDRG02 was characterized in the downstream region of the transcriptional start, named as 5'-untranslated region (5'UTR), consisting of one 93 bp 5'-untranslation exon, one 213 bp intron and one 441 bp TIR-encoding open reading frame (ORF). In addition, several putative cis-acting motifs were present in the obtained TIR-specific promoter of PtDRG02,including one TATA box, one GC-rich, one AT-rich, one P-box, one 3-AF1 binding site, two CAAT boxes, two GT-1 motifs, three typical W-boxes, four Ⅰ-boxes, and one multi-cis-acting fragment (MCF). The latter contains five types of regulatory elements (E4,G-box, ABRE motif, boxl and HVAls), most of which were homologous to the cis-acting regulatory elements involved in the activation of defense genes in plants. Thus, it can be suggested that TIR-specific promoter might be a pathogen-inducible promoter and be necessary for the inducible expression of defense-related genes.

  18. Ovipositional preference and larval performance of poplar defoliator,Clostera restitura on different poplar clones in north-western India

    Institute of Scientific and Technical Information of China (English)

    Gurmail Singh; K.S. Sangha

    2012-01-01

    We evaluated ten poplar clones (G-3,G-48,L-50/88,L154/84,L-156/89,S7C8,S7C15.WSL-22,WSL-29 and Uday) for ovipositional preference and larval performance of Clostera restitura.Female moths did not show any preference with respect to clones for oviposition.Significant differences were observed for number of eggs laid on different plant parts.C.restitura laid eggs in clusters,preferably on upper surface of leaf and size of the egg cluster varied from 15 to 167 eggs.Clones varied for their relative resistance and susceptibility to C.restitura.L-50/88; L-156/89 were identified as most resistant clone based on minimum leaf consumption,whereas S7C15 was found to be most susceptible clone to C.restitura.In multiple choice experiments,no feeding preference by C restitura larvae was detected amongst different poplar clones.After initial settlement of larvae on a particular clone,the larvae remained confined to that clone and negligible inter-clonal movement was noticed subsequently.The fresh pupal weight was correlated negatively (r =-0.37) with percentage surface leaf area eaten and positively (r =0.47) with length of larval period,measured on different clones.Relationship between percentage leaf area eaten and length of larval period was negative (r =-0.23).Owing to relative resistance of L50/88 and L-156/89 against C.restitura,these clones can be recommended for plantation in defoliator prone areas in north-western India.

  19. Laser impingement on bare and encased high explosives: safety limits

    Energy Technology Data Exchange (ETDEWEB)

    Roeske, F

    1999-03-15

    During the course of experiments involving high explosives, (HE), alignment lasers are often employed where the laser beam impinges upon a metal encased HE sample or on the bare HE itself during manned operations. While most alignment lasers are of low enough power so as not to be of concern, safety questions arise when considering the maximum credible power output of the laser in a failure mode, or when multiple laser spots are focused onto the experiment simultaneously. Safety questions also arise when the focused laser spot size becomes very small, on the order of 100 {micro}m or less. This paper addresses these concerns by describing a methodology for determining safety margins for laser impingement on metal encased HE as well as one for bare HE. A variety of explosives encased in Al, Cu, Ta and stainless steel were tested using the first of these techniques. Additional experiments were performed using the second method where the laser beam was focused directly on eight different samples of pressed-powder HE.

  20. Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, Andreas H., E-mail: mahnken@med.uni-marburg.de [University Hospital Giessen and Marburg, Philipps University of Marburg, Department of Diagnostic Radiology (Germany); Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M., E-mail: anneke.damberg@rwth-aachen.de [University Hospital RWTH Aachen, Department of Thoracic, Cardiac and Vascular Surgery (Germany)

    2013-08-01

    BackgroundAortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described.MethodsWe report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case.ResultsBoth procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence.ConclusionTreating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

  1. Iron line profiles in Suzaku spectra of bare Seyfert galaxies

    CERN Document Server

    Patrick, A R; Porquet, D; Markowitz, A G; Lobban, A P; Terashima, Y

    2010-01-01

    We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG-02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of bare Seyferts allows a consistent and physical modelling of AGN due to a weak amount of any intrinsic warm absorption, removing the degeneracy between the spectral curvature due to warm absorption and the red-wing of the Fe K region. Through effective modelling of the broad-band spectrum and investigating the presence of narrow neutral or ionized emission lines and reflection from distant material, we obtain an accurate and detailed description of the Fe K line region using models such as laor, kerrdisk and kerrconv. Results suggest that ionized emission lines at 6.7 keV and 6.97 keV (particularly Fe XXVI) are relatively common and the inclusion of these lines can greatly affect the parameters obtained with relativistic models i.e. spin, emissivity, inner radius of emission and inclination. Moderately broad components...

  2. Nutrient Dynamics of Fine Roots in the Mixed Plantation of Poplar and Black Locust

    Institute of Scientific and Technical Information of China (English)

    Zhai Mingpu; Jiang Sannai; Jia Liming

    2006-01-01

    The mixed plantation of poplar (Populus spp.)and black locust (Robinia pseudoacacia) is one of the typical mixed stands with nitrogen-fixing and non-nitrogen-fixing species.Interaction between the two species in the mixed stand is harmonious and productivity is high,making this kind of mixed plantation a very successful pattern on poor sandy sites in north China.In this study,the fine root decomposition of the two species was investigated in the mixed plantation of 27-year-old Canadian poplar (P.canadansis)and 22-year-old black locust on sandy sites along the Chaobai River in Beijing.Mechanism of harmonious interaction between the two species was observed in the view of the nutrient cycle of fine roots.Results showed that:(1) the fine root decomposition of Canadian poplar and black locust trees was different.Concentrations of N,Ca and Mg gradually increased and those of P and K gradually decreased in the fine roots of poplar during the period of decomposition.Concentrations of N,P and K gradually decreased in the fine roots of black locust during decomposition.The speed of nutrient decomposition in mixed fine roots of the two species fell between the speed of the two pure samples.(2) During decomposition,the annual return amount of N,K and Mg in fine roots of black locust was highest,followed by the mixed fine roots of the two species,and then the fine roots of poplar.(3) The increased return amount of N in mixed fine roots could improve the N nutrient condition of poplar trees.The return amount of P in poplar Fine roots was greater than that of black locust,which could improve the P nutrient of black locust trees.The interaction of mutual supplements of N and P nutrient cycle of fine roots between these two species formed.

  3. COMPARISON OF APMP PULP CHARACTERISTICS OF JUVENILE TRIPLOID CHINESE WHITE POPLAR IN SALINE SOIL WITH THAT OF NORMAL 5-YEAR POPLAR

    Institute of Scientific and Technical Information of China (English)

    Hongchun Zou; Guomin Tan; Qun Li; Zimin Zhang

    2004-01-01

    In the paper, differences between the juvenile Triploid Chinese White Poplar TCWP in saline soil and 5-year TCWP in normal soil are compared in terms of their APMP-pulping properties. The results show that the saline planting environment does not show obvious effects on pulping properties of juvenile TCWP.

  4. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    Science.gov (United States)

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-07-27

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects.

  5. Fertilization effects on biomass production, nutrient leaching and budgets in four stand development stages of short rotation forest poplar

    DEFF Research Database (Denmark)

    Georgiadis, Petros; Nielsen, Anders Tærø; Stupak, Inge

    2017-01-01

    Abstract Dedicated energy poplar plantations have a high biomass production potential in temperate regions, which may be further increased by improved management practices. The aim of this study was to investigate the effects of fertilization on short rotation forest poplar established on former...

  6. [Canopy conductance characteristics of poplar in agroforestry system in west Liaoning Province of Northeast China].

    Science.gov (United States)

    Li, Zheng; Niu, Li-Hua; Yuan, Feng-Hui; Guan, De-Xin; Wang, An-Zhi; Jin, Chang-Jie; Wu, Jia-Bing

    2012-11-01

    By using Granier' s thermal dissipation probe, the sap flow of poplar in a poplar-maize agroforestry system in west Liaoning was continuously measured, and as well, the environmental factors such as air temperature, air humidity, net radiation, wind speed, soil temperature, and soil moisture content were synchronically measured. Based on the sap flow data, the canopy conductance of poplar was calculated with simplified Penman-Monteith equation. In the study area, the diurnal variation of poplar' s canopy conductance showed a "single peak" curve, whereas the seasonal variation showed a decreasing trend. There was a negative logarithm relationship between the canopy conductance and vapor pressure deficit, with the sensitivity of canopy conductance to vapor pressure deficit change decreased gradually from May to September. The canopy conductance had a positive relationship with solar radiation. In different months, the correlation degree of canopy conductance with environmental factors differed. The vapor pressure deficit in the whole growth period of poplar was the most significant environmental factor correlated with the canopy conductance.

  7. Obtaining the transgenic poplars with low lignin content through down-regulation of 4CL

    Institute of Scientific and Technical Information of China (English)

    JIA Caihong; ZHAO Huayan; WANG Hongzhi; XING Zhifeng; DU Kejiu; SONG Yanru; WEI Jianhua

    2004-01-01

    The antisense 4CL (4-coumarate: CoA ligase) gene was transformed into triploid Chinese white poplar (Populus tomentosa) mediated by Agrobacterium tumefaciens. PCR and Southern blot analysis indicated that antisense 4CL gene had been integrated into the genome of the transgenic Chinese white poplars. The antisense gene had also been expressed, which was indicated by RT-PCR and Western analysis. Klason lignin content assay showed that repression of 4CL expression could result in remarkable reduction of lignin content in transgenic poplars, with most reduction of 41.73% compared with that of wild type in this paper. But there is no significant difference in holocellulose content between trans- genic and wild poplars. We considered that 4CL might not be the metabolism control point between lignin and carbohy- drate biosynthesis. The stems of transgenic poplars displayed red-brown color with different levels after the bark was peeled, while those of untransformed plants were white. No visible differences in growth and development were observed between transgenic and wild plants. Wiesner reaction analysis of the transgenic plant stems with reduced lignin content exhibited red color, while that of untransformed plant was typically purple-red.

  8. In Silico Identification and Characterization of N-Terminal Acetyltransferase Genes of Poplar (Populus trichocarpa

    Directory of Open Access Journals (Sweden)

    Hang-Yong Zhu

    2014-01-01

    Full Text Available N-terminal acetyltransferase (Nats complex is responsible for protein N-terminal acetylation (Nα-acetylation, which is one of the most common covalent modifications of eukaryotic proteins. Although genome-wide investigation and characterization of Nat catalytic subunits (CS and auxiliary subunits (AS have been conducted in yeast and humans they remain unexplored in plants. Here we report on the identification of eleven genes encoding eleven putative Nat CS polypeptides, and five genes encoding five putative Nat AS polypeptides in Populus. We document that the expansion of Nat CS genes occurs as duplicated blocks distributed across 10 of the 19 poplar chromosomes, likely only as a result of segmental duplication events. Based on phylogenetic analysis, poplar Nat CS were assigned to six subgroups, which corresponded well to the Nat CS types (CS of Nat A–F, being consistent with previous reports in humans and yeast. In silico analysis of microarray data showed that in the process of normal development of the poplar, their Nat CS and AS genes are commonly expressed at one relatively low level but share distinct tissue-specific expression patterns. This exhaustive survey of Nat genes in poplar provides important information to assist future studies on their functional role in poplar.

  9. Two Highly Similar Poplar Paleo-subgenomes Suggest an Autotetraploid Ancestor of Salicaceae Plants.

    Science.gov (United States)

    Liu, Yinzhe; Wang, Jinpeng; Ge, Weina; Wang, Zhenyi; Li, Yuxian; Yang, Nanshan; Sun, Sangrong; Zhang, Liwei; Wang, Xiyin

    2017-01-01

    As a model plant to study perennial trees in the Salicaceae family, the poplar (Populus trichocarpa) genome was sequenced, revealing recurrent paleo-polyploidizations during its evolution. A comparative and hierarchical alignment of its genome to a well-selected reference genome would help us better understand poplar's genome structure and gene family evolution. Here, by adopting the relatively simpler grape (Vitis vinifera) genome as reference, and by inferring both intra- and inter-genomic gene collinearity, we produced a united alignment of these two genomes and hierarchically distinguished the layers of paralogous and orthologous genes, as related to recursive polyploidizations and speciation. We uncovered homologous blocks in the grape and poplar genomes and also between them. Moreover, we characterized the genes missing and found that poplar had two considerably similar subgenomes (≤0.05 difference in gene deletion) produced by the Salicaceae-common tetraploidization, suggesting its autotetraploid nature. Taken together, this work provides a timely and valuable dataset of orthologous and paralogous genes for further study of the genome structure and functional evolution of poplar and other Salicaceae plants.

  10. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    Science.gov (United States)

    Foster, Adam J; Pelletier, Gervais; Tanguay, Philippe; Séguin, Armand

    2015-01-01

    Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen.

  11. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    Directory of Open Access Journals (Sweden)

    Adam J Foster

    Full Text Available Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen.

  12. Evapotranspiration and crop coefficient of poplar and willow short-rotation coppice used as vegetation filter.

    Science.gov (United States)

    Guidi, Werther; Piccioni, Emiliano; Bonari, Enrico

    2008-07-01

    Ten-day evapotranspiration (ETc) and crop coefficient (k(c)) of willow and poplar SRC used as vegetation filter and grown under fertilised (F) and unfertilised (NF) conditions, were determined for two successive growing seasons using volumetric lysimeters. During the first growing season, total ETc observed was, respectively, 620 (NF)-1190 (F)mm in willow and 590 (NF)-725 (F) in poplar. During the second growing season, ETc showed a general increase, mainly in fertilised lysimeters where it ranged between 890 (NF)-1790 mm (F) in willow and 710 (NF)-1100 mm (NF) in poplar. kc reached in both years its maximum between the end of August and the beginning of September. In 2004 maximum kc ranged from 1.25-2.84 in willow and 1.06-1.90 in poplar, whereas in 2005 it ranged from 1.97-5.30 in willow and 1.71-4.28 in poplar. ETc seemed to be strongly correlated to plant development and mainly dependent on its nutritional status rather than on the differences between the species.

  13. Relationship between plant hormone level excreted by ectomycorrhizal fungi and growth of poplar NL-895

    Institute of Scientific and Technical Information of China (English)

    Lei MA; Xiaoqin WU; Ling ZHENG

    2009-01-01

    To explore the effects of plant hormones levels excreted by ectomycorrhizal (ECM) fungi on the growth of poplars, Populus x euramericana cv. NL-895 seedlings were inoculated with nine species of ECM fungi. We investigated the status of ectomycorrhizal formation and the effects of these fungi on poplar growth, and using the HPLC method, we measured the contents of four kinds of plant hormones, indole acetic acid (IAA), zeatin (Z), gibberellin (GA) and abscisic acid (ABA) in both the culture filtrate and the mycelium of these fungi. The results showed that the effects of nine ECM fungi on the growth of poplar NL-895 varied. The inoculated seedlings, whether or not obvious mycorrhizas were developed, grew better than those non-inoculated ones. All nine ectomycorrhizal fungi excreted the four plant hormones, but at different levels. The hormone contents in culture filtrate were higher than that in mycelium, which showed a definite relationship with poplar growth. Significantly, correlation analysis suggested the height and stem diameter of the poplar were positively correlated with zeatin contents in the mycelium, and were negatively correlated with the levels of ABA or IAA in the mycelium.

  14. Corrosion of bare and galvanized steel in gypsum

    Directory of Open Access Journals (Sweden)

    Gómez, Mercedes

    1988-12-01

    Full Text Available Gypsum is a relatively low-cost building material much abounding in our country. When it is put in contact with steel, it may produce high corrosion rates due to its pH value (close to 7. This work reports the results obtained in studying the corrosion rates of bare and galvanized steel in contact with gypsum and plaster, as well as the influence curing thermal treatment applied to gypsum, enviromental relative humidity and addition of compounds with different natures and purposes may have in such process. In-situ observations, as well as the measurement of the Polarization Resistance and the weight loss have been used as measurement technics. From the results obtained it has been possible to deduce that galvanized steel has better behaviour in dry enviroments than bare steel in the same conditions and moist atmosphere induces proportionally more corrosion in galvanized steel than in bare one. Additions to gypsum do not modified these conclusions, though it may be pointed out that addition of nitrites or lime improves the behaviour of bare steel, while galvanized behaviour is not modified. The addition of lime is not recommended because phenomena of dilated along time expansion may take place.

    El yeso es un material de construcción de relativo bajo coste y que, además, es muy abundante en nuestro país. Debido a su pH cercano a la neutralidad, cuando entra en contacto con el acero, este puede corroerse a elevadas velocidades. En esta comunicación se presentan los resultados de un estudio sobre la velocidad de corrosión del acero desnudo y galvanizado en contacto con yeso y escayola y la influencia que tienen: el tratamiento térmico del curado del yeso, la humedad relativa ambiental y la adición de aditivos de diversa naturaleza y finalidad. Como técnicas de medida se han utilizado la medida de la Resistencia de Polarización y de la pérdida de peso, así como observaciones visuales. De los resultados se puede deducir que en

  15. Achievement of a superpolish on bare stainless steel

    Science.gov (United States)

    Howells, Malcolm R.; Casstevens, John M.

    1997-11-01

    We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 angstroms, as measured by an optical profiler with a bandwidth 0.29 - 100 mm-1. The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufacturability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible reasons for its unusual stability and polishability.

  16. Radiative Capture of Twisted Electrons by Bare Ions

    CERN Document Server

    Matula, Oliver; Serbo, Valeriy G; Surzhykov, Andrey; Fritzsche, Stephan

    2014-01-01

    Recent advances in the production of twisted electron beams with a subnanometer spot size offer unique opportunities to explore the role of orbital angular momentum (OAM) in basic atomic processes. In the present work, we address one of these processes: radiative recombination of twisted electrons with bare ions. Based on the density matrix formalism and the non-relativistic Schr\\"odinger theory, analytical expressions are derived for the angular distribution and the linear polarization of photons emitted due to the capture of twisted electrons into the ground state of (hydrogen-like) ions. We show that these angular and polarization distributions are sensitive to both, the transverse momentum and the topological charge of the electron beam. To observe in particular the value of this charge, we propose an experiment that makes use of the coherent superposition of two twisted beams.

  17. Diurnal emissivity dynamics in bare versus biocrusted sand dunes

    Science.gov (United States)

    Rozenstein, O.

    2015-12-01

    Land surface emissivity (LSE) in the thermal infrared depends mainly on the ground cover and on changes in soil moisture. The LSE is a critical variable that affects the prediction accuracy of geophysical models requiring land surface temperature as an input, highlighting the need for an accurate derivation of LSE. The primary aim of this study was to test the hypothesis that diurnal changes in emissivity, as detected from space, are larger for areas mostly covered by biocrusts (composed mainly of cyanobacteria) than for bare sand areas. The LSE dynamics were monitored from geostationary orbit by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) over a sand dune field in a coastal desert region extending across both sides of the Israel-Egypt political borderline. Different land-use practices by the two countries have resulted in exposed, active sand dunes on the Egyptian side (Sinai), and dunes stabilized by biocrusts on the Israeli side (Negev). Since biocrusts adsorb more moisture from the atmosphere than bare sand does, and LSE is affected by the soil moisture, diurnal fluctuations in LSE were larger for the crusted dunes in the 8.7 μm channel. This phenomenon is attributed to water vapor adsorption by the sand / biocrust particles. The results indicate that LSE is sensitive to minor changes in soil water content caused by water vapor adsorption and can, therefore, serve as a tool for quantifying this effect, which has a large spatial impact. As biocrusts cover vast regions in deserts worldwide, this discovery has repercussions for LSE estimations in deserts around the globe, and these LSE variations can potentially have considerable effects on geophysical models from local to regional scales.

  18. Diurnal emissivity dynamics in bare versus biocrusted sand dunes.

    Science.gov (United States)

    Rozenstein, Offer; Agam, Nurit; Serio, Carmine; Masiello, Guido; Venafra, Sara; Achal, Stephen; Puckrin, Eldon; Karnieli, Arnon

    2015-02-15

    Land surface emissivity (LSE) in the thermal infrared depends mainly on the ground cover and on changes in soil moisture. The LSE is a critical variable that affects the prediction accuracy of geophysical models requiring land surface temperature as an input, highlighting the need for an accurate derivation of LSE. The primary aim of this study was to test the hypothesis that diurnal changes in emissivity, as detected from space, are larger for areas mostly covered by biocrusts (composed mainly of cyanobacteria) than for bare sand areas. The LSE dynamics were monitored from geostationary orbit by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) over a sand dune field in a coastal desert region extending across both sides of the Israel-Egypt political borderline. Different land-use practices by the two countries have resulted in exposed, active sand dunes on the Egyptian side (Sinai), and dunes stabilized by biocrusts on the Israeli side (Negev). Since biocrusts adsorb more moisture from the atmosphere than bare sand does, and LSE is affected by the soil moisture, diurnal fluctuations in LSE were larger for the crusted dunes in the 8.7 μm channel. This phenomenon is attributed to water vapor adsorption by the sand/biocrust particles. The results indicate that LSE is sensitive to minor changes in soil water content caused by water vapor adsorption and can, therefore, serve as a tool for quantifying this effect, which has a large spatial impact. As biocrusts cover vast regions in deserts worldwide, this discovery has repercussions for LSE estimations in deserts around the globe, and these LSE variations can potentially have considerable effects on geophysical models from local to regional scales.

  19. Design and Use of a Guided Weight Impactor to Impart Barely Visible Impact Damage

    Science.gov (United States)

    Lovejoy, Andrew E.; Przekop, Adam

    2016-01-01

    Aircraft structure is required to demonstrate satisfaction of the FAR requirements for Category 1, such as barely visible impact damage (BVID). Typical aircraft structure is impacted using a dropped weight impactor, which can impart BVID to the top surface of the structure. A recent test of a multi-bay box (MBB) composite test article, that represents an 80% scale center section of a hybrid wing body aircraft, required impact to be in a direction other than vertical from above, but still in an direction that is normal to the surface. This requirement eliminated the use of the conventional dropped weight impactor. Therefore, a design study was undertaken to determine the most effective way to efficiently and reliably impact the MBB. The chosen design was a guided weight impactor that is gravity driven. This paper describes the design of the guided weight impactor, and presents the results of its use for imparting BVID to the MBB. The guided weight impactor was seen to be a very reliable method to impart BVID, while at the same time having the capability to be highly configurable for use on other aircraft structure that is impacted at a variety of impact energies and from a variety of directions.

  20. MCP detector read out with a bare quad Timepix at kilohertz frame rates

    Science.gov (United States)

    Vallerga, J.; Raffanti, R.; Tremsin, A.; McPhate, J.; Siegmund, O.

    2011-01-01

    The existing Berkeley neutron sensitive MCP/Timepix hybrid detector has been very successful at demonstrating energy resolved spatial imaging with a single Timepix ASIC read out at a ~ 30 Hz frame rate where each neutron's position and time (energy) is determined (X,Y,E). By increasing the detector format using a quad arrangement of Timepix readouts and increasing the frame rate to 1 kHz, we can increase our total event throughput by a factor of 120, thereby taking full advantage of the high fluxes of modern pulsed neutron sources (106 n cm-2 s-1). The key to this conversion is a new design for the ASIC readout, called the Berkeley Quad Timepix detector, consisting of 3 major subsystems. The first is a quad (2 × 2) bare Timepix ASIC board mounted directly behind the neutron sensitive MCPs in a hermetic vacuum enclosure with a sapphire window. The data from the Timepix ASICs flow to the second subsystem called the Interface board whose field programmable gate array (FPGA) rearranges and converts the digital bit stream to LVDS logic levels before sending downstream to the third subsystem, the Roach board. The Roach board is also FPGA based, and takes the data from all the ASICs and analyses the frames to extract information on the input events to pass on to the host PC. This paper describes in detail the hardware and firmware designs to accomplish this task.

  1. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS, S.M.; BEATY, T.W.; BRANDT, C.C.; CHRISTENSEN, S.W.; CICERONE, D.S.

    1998-09-09

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  2. Genomics Mechanisms of Carbon Allocation and Partitioning in Poplar

    Energy Technology Data Exchange (ETDEWEB)

    Kirst, Matias; Peter, Gary; Martin, Timothy

    2009-07-30

    The genetic control of carbon allocation and partitioning in woody perennial plants is poorly understood despite its importance for carbon sequestration. It is also unclear how environmental cues such as nitrogen availability impact the genes that regulate growth, and biomass allocation and wood composition in trees. To address these questions we phenotyped 396 clonally replicated genotypes of an interspecific pseudo-backcross pedigree of Populus for wood composition and biomass traits in above and below ground organs. The loci that regulate growth, carbon allocation and partitioning under two nitrogen conditions were identified, defining the contribution of environmental cues to their genetic control. Fifty-seven quantitative trait loci (QTL) were identified for twenty traits analyzed. The majority of QTL are specific to one of the two nitrogen treatments, demonstrating significant nitrogen-dependent genetic control. A highly significant genetic correlation was observed between plant growth and lignin/cellulose composition, and QTL co-localization identified the genomic position of potential pleiotropic regulators. Gene expression analysis of all poplar genes was also characterized in differentiating xylem, whole-roots and developing leaves of 192 of the segregating population. By integrating the QTL and gene expression information we identified genes that regulate carbon partitioning and several biomass growth related properties. The work developed in this project resulted in the publication of three book chapters, four scientific articles (three others currently in preparation), 17 presentations in international conferences and two provisional patent applications.

  3. Soil Investigation of Lower East Fork Poplar Creek

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Johnbull O [ORNL; Mayes, Melanie [ORNL; Earles, Jennifer E [ORNL; Mehlhorn, Tonia L [ORNL; Lowe, Kenneth Alan [ORNL; Peterson, Mark J [ORNL; Pierce, Eric M [ORNL

    2017-03-01

    Mercury is regarded by the US Department of Energy (DOE) Oak Ridge Office of Environmental Management as a priority contaminant on the Oak Ridge Reservation because of the environmental risks associated with substantial losses from buildings, soils, and surface waters at the Y-12 National Security Complex (Y-12). As a result of historical releases of mercury from Y-12 primarily in the 1950s and early 1960s, the lower East Fork Poplar Creek (LEFPC) stream channel and bank soil margins are contaminated with mercury (Brooks and Southworth 2011; Tennessee Valley Authority 1985b, a). A Mercury Remediation Technology Development project is underway to evaluate the nature of downstream mercury contamination and to develop targeted site-specific remedial technologies that can mitigate mercury release and biological uptake. It is known that mercury concentration varies longitudinally and with depth in LEFPC bank soils; however, soil types and soil physical properties are not well known, especially relative to the zones of mercury contamination. Moreover, there are no soil maps for the downstream reaches of LEFPC in Roane County (i.e. from the Chestnut Hill Road downstream) and this work represents the first ever soil mapping along this section of LEFPC.

  4. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS, S.M.; ASHWOOD, T.L.; BEATY, T.W.; BRANDT, C.C.

    1997-10-24

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y- 12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  5. Surface Characterization of Plasma-modified Poplar Veneer: Dynamic Wettability

    Directory of Open Access Journals (Sweden)

    Lijuan Tang

    2014-11-01

    Full Text Available The dynamic wettability of plasma-modified poplar veneer was investigated with sessile adhesive droplets using a wetting model. Dynamic contact angle, instantaneous and equilibrium contact angles, and their rates of change (K-value were used to illustrate the dynamic wetting process. The experiment consisted of selecting treatment parameters (type of gas, power that would lead to the increased wettability of wood. Three resin systems, urea-formaldehyde (UF, phenol-formaldehyde (PF, and diphenylmethylene diisocyanate (MDI, were evaluated. Based on the wetting model, the K-value was used to interpret the kinetics of wetting. The higher the K-value, the faster the contact angle reaches equilibrium, and the faster the liquid penetrates and spreads. Therefore, the model was helpful for characterizing the dynamic wettability of wood surfaces modified with different plasma treatments. The K-values of plasma-treated veneer surfaces at different plasma power levels and with different gases (such as O2, N2, Ar, air, and NH3 were 458% to 653% and 332% to 528% higher than those of untreated veneer surfaces, respectively. In addition, the K-values of the three resins on the oxygen plasma-treated veneer surfaces were 38% to 1204% higher than those on the untreated veneer surfaces. Therefore, this method was helpful for characterizing the dynamic wettability of veneer surfaces modified with plasma treatment.

  6. Effect of autohydrolysis on the wettability, absorbility and further alkali impregnation of poplar wood chips.

    Science.gov (United States)

    Xu, Ningpan; Liu, Wei; Hou, Qingxi; Wang, Peiyun; Yao, Zhirong

    2016-09-01

    Autohydrolysis with different severity factors was performed on poplar wood chips prior to pulping, and the wettability, absorbility and the following impregnation of NaOH solution for the poplar wood chips were then investigated. The results showed that after autohydrolysis pretreatment the porosity, shrinkage and fiber saturation point (FSP) of the poplar wood chips were increased, while the surface contact angle decreased as the severity factor was increased. The autohydrolyzed chips absorbed more NaOH in impregnation that resulted in a low NaOH concentration in the bulk impregnation liquor (i.e., the impregnation liquor outside wood chips), while the concentration in the entrapped liquor (i.e., the impregnation liquor inside wood chips) was increased. Autohydrolysis substantially improved the effectiveness of alkali impregnation.

  7. Daytime and nighttime wind differentially affects hydraulic properties and thigmomorphogenic response of poplar saplings.

    Science.gov (United States)

    Huang, Ping; Wan, Xianchong; Lieffers, Victor J

    2016-05-01

    This study tested how wind in daytime and nighttime affects hydraulic properties and thigmomorphogenic response of poplar saplings. It shows that wind in daytime interrupted water balance of poplar plants by aggravating cavitation in the stem xylem under high xylem tension in the daytime, reducing water potential in midday and hence reducing gas exchange, including stomatal conductance and CO2 assimilation. The wind blowing in daytime significantly reduced plant growth, including height, diameter, leaf size, leaf area, root and whole biomass, whereas wind blowing in nighttime only caused a reduction in radial and height growth at the early stage compared with the control but decreased height:diameter ratios. In summary, the interaction between wind loading and xylem tension exerted a negative impact on water balance, gas exchanges and growth of poplar plants, and wind in nighttime caused only a small thigmomorphogenic response.

  8. Physical and chemical characterizations of corn stover and poplar solids resulting from leading pretreatment technologies.

    Science.gov (United States)

    Kumar, Rajeev; Mago, Gaurav; Balan, Venkatesh; Wyman, Charles E

    2009-09-01

    In order to investigate changes in substrate chemical and physical features after pretreatment, several characterizations were performed on untreated (UT) corn stover and poplar and their solids resulting pretreatments by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid, flowthrough, lime, and SO(2) technologies. In addition to measuring the chemical compositions including acetyl content, physical attributes determined were biomass crystallinity, cellulose degree of polymerization, cellulase adsorption capacity of pretreated solids and enzymatically extracted lignin, copper number, FT-IR responses, scanning electron microscopy (SEM) visualizations, and surface atomic composition by electron spectroscopy of chemical analysis (ESCA). Lime pretreatment removed the most acetyl groups from both corn stover and poplar, while AFEX removed the least. Low pH pretreatments depolymerized cellulose and enhanced biomass crystallinity much more than higher pH approaches. Lime pretreated corn stover solids and flowthrough pretreated poplar solids had the highest cellulase adsorption capacity, while dilute acid pretreated corn stover solids and controlled pH pretreated poplar solids had the least. Furthermore, enzymatically extracted AFEX lignin preparations for both corn stover and poplar had the lowest cellulase adsorption capacity. ESCA results showed that SO(2) pretreated solids had the highest surface O/C ratio for poplar, but for corn stover, the highest value was observed for dilute acid pretreatment with a Parr reactor. Although dependent on pretreatment and substrate, FT-IR data showed that along with changes in cross linking and chemical changes, pretreatments may also decrystallize cellulose and change the ratio of crystalline cellulose polymorphs (Ialpha/Ibeta).

  9. Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment.

    Science.gov (United States)

    Dimitrova, Tsvetelina; Repmann, Frank; Raab, Thomas; Freese, Dirk

    2015-04-01

    Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg(-1) for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l(-1). The maximum cyanide content in willow and poplar leaves was 518 mg kg(-1) fresh weight (FW) and 148 mg kg(-1) FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l(-1) and for willow after 8 weeks of exposure-768 mg l(-1). Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides.

  10. Apoplast proteome reveals that extracellular matrix contributes to multistress response in poplar

    Directory of Open Access Journals (Sweden)

    Lawrence Amanda M

    2010-11-01

    Full Text Available Abstract Background Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development. Results We report that poplar (Populus spp. has evolved a systems level "stress proteome" in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from P. deltoides, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen Melampsora. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast. Conclusion These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.

  11. Changes in sulphur metabolism of grey poplar (Populus x canescens) leaves during salt stress: a metabolic link to photorespiration.

    Science.gov (United States)

    Herschbach, Cornelia; Teuber, Markus; Eiblmeier, Monika; Ehlting, Barbara; Ache, Peter; Polle, Andrea; Schnitzler, Jörg-Peter; Rennenberg, Heinz

    2010-09-01

    The poplar hybrid Populus x canescens (syn. Populus tremula x Populus alba) was subjected to salt stress by applying 75 mM NaCl for 2 weeks in hydroponic cultures. Decreasing maximum quantum yield (Fv/Fm) indicated damage of photosystem II (PS II), which was more pronounced under nitrate compared with ammonium nutrition. In vivo staining with diaminobenzidine showed no accumulation of H(2)O(2) in the leaf lamina; moreover, staining intensity even decreased. But at the leaf margins, development of necrotic tissue was associated with a strong accumulation of H(2)O(2). Glutathione (GSH) contents increased in response to NaCl stress in leaves but not in roots, the primary site of salt exposure. The increasing leaf GSH concentrations correlated with stress-induced decreases in transpiration and net CO(2) assimilation rates at light saturation. Enhanced rates of photorespiration could also be involved in preventing reactive oxygen species formation in chloroplasts and, thus, in protecting PS II from damage. Accumulation of Gly and Ser in leaves indeed indicates increasing rates of photorespiration. Since Ser and Gly are both immediate precursors of GSH that can limit GSH synthesis, it is concluded that the salt-induced accumulation of leaf GSH results from enhanced photorespiration and is thus probably restricted to the cytosol.

  12. Can we use short rotation coppice poplar for sugar based biorefinery feedstock? Bioconversion of 2-year-old poplar grown as short rotation coppice.

    Science.gov (United States)

    Dou, Chang; Marcondes, Wilian F; Djaja, Jessica E; Bura, Renata; Gustafson, Rick

    2017-01-01

    Feedstock cost is a substantial barrier to the commercialization of lignocellulosic biorefineries. Poplar grown using a short rotation coppice (SRC) system has the potential to provide a low-cost feedstock and economically viable sugar yields for fuels and chemicals production. In the coppice management regime, poplars are harvested after 2 years' growth to develop the root system and establish the trees. The biomass from these 2-year-old trees is very heterogeneous, and includes components of leaf, bark, branch, and wood chip. This material is quite different than the samples that have been used in most poplar bioconversion research, which come from mature trees of short rotation forestry (SRF) plantations. If the coppice management regime is to be used, it is important that feedstock growers maximize their revenue from this initial harvest, but the heterogeneous nature of the biomass may be challenging for bioconversion. This work evaluates bioconversion of 2-year-old poplar coppice and compares its performance to whitewood chips from 12-year-old poplar. The 2-year-old whole tree coppice (WTC) is comprised of 37% leaf, 9% bark, 12% branch, and 42% wood chip. As expected, the chemical compositions of each component were markedly different. The leaf has a low sugar content but is high in phenolics, ash, and extractives. By removing the leaves, the sugar content of the biomass increased significantly, while the phenolic, ash, and extractives contents decreased. Leaf removal improved monomeric sugar yield by 147 kg/tonne of biomass following steam pretreatment and enzymatic hydrolysis. Bioconversion of the no-leaf coppice (NLC) achieved a 67% overall sugar recovery, showing no significant difference to mature whitewood from forestry plantation (WWF, 71%). The overall sugar yield of NLC was 135 kg/tonne less than that of WWF, due to the low inherent sugar content in original biomass. An economic analysis shows the minimum ethanol selling price required to cover the

  13. Study on Drying Characteristic of Chinese Fir and Poplar Plantation Wood

    Institute of Scientific and Technical Information of China (English)

    ZHOUYongdong; LIXiaoling

    2004-01-01

    The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through lO0-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.

  14. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare Earth

    Science.gov (United States)

    Smith, Kathryn E.L.; Nayegandhi, Amar; Wright, C. Wayne; Bonisteel, Jamie M.; Brock, John C.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. The purpose of this project is to provide highly detailed and accurate datasets of select barrier islands and peninsular regions of Louisiana, Mississippi, Alabama, and Florida, acquired on June 27-30, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using

  15. EAARL Coastal Topography - Northeast Barrier Islands 2007: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Sallenger, A.H.; Wright, C. Wayne; Yates, Xan; Bonisteel, Jamie M.

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the northeast coastal barrier islands in New York and New Jersey, acquired April 29-30 and May 15-16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom

  16. EAARL Topography - Vicksburg National Military Park 2008: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Segura, Martha; Yates, Xan

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the Vicksburg National Military Park in Mississippi, acquired on March 6, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed

  17. EAARL Coastal Topography-Chandeleur Islands, Louisiana, 2010: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Bonisteel-Cormier, Jamie M.; Brock, John C.; Sallenger, A.H.; Wright, C. Wayne; Nagle, David B.; Vivekanandan, Saisudha; Yates, Xan; Klipp, Emily S.

    2010-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived bare-earth (BE) and submerged topography datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Chandeleur Islands, acquired March 3, 2010. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color-infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom

  18. EAARL Coastal Topography-Pearl River Delta 2008: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Miner, Michael D.; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the University of New Orleans (UNO), Pontchartrain Institute for Environmental Sciences (PIES), New Orleans, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Pearl River Delta in Louisiana and Mississippi, acquired March 9-11, 2008. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the

  19. Growth and carbohydrate status of coppice shoots of hybrid poplar following shoot pruning.

    Science.gov (United States)

    Tschaplinski, T J; Blake, T J

    1995-05-01

    Fifteen, 1-year-old Populus maximowiczii Henry x P. nigra L. 'MN9' trees were decapitated and allowed to sprout. After 8 weeks, all had 6 to 10 coppice shoots. All shoots, except the tallest (dominant) shoot, were removed from five of the trees (pruned treatment), and shoot growth, gas exchange and carbohydrate status were compared in the pruned and unpruned trees. Although photosynthetic rate of recently mature leaves of pruned trees was approximately 50% greater than that of leaves on the dominant shoot of unpruned trees, and the dry weight of leaves of pruned trees was 37% greater than that of the leaves on the dominant shoot of unpruned trees, the shoot dry matter relative growth rate did not differ between treatments. Concentrations of water-soluble carbohydrates and starch in the uppper stem and leaves of the dominant shoot were similar in pruned and unpruned trees. However, relative to that of the dominant shoot in unpruned trees, the lower stem in pruned trees was depleted in both soluble carbohydrates and starch. Starch deposition, assessed as the quantity of (14)C-starch in tissues 24 h after a fully expanded source leaf was labeled with (14)CO(2), was 3.9 times greater in roots of pruned trees than in roots of unpruned trees. We conclude that early removal of all but the dominant shoot reduces the carbohydrate status of the roots and the lower portion of the stem by eliminating the excised shoots as a source of photosynthate.

  20. Expression of multiple resistance genes enhances tolerance to environmental stressors in transgenic poplar (Populus × euramericana 'Guariento'.

    Directory of Open Access Journals (Sweden)

    Xiaohua Su

    Full Text Available Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana 'Guariento' harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although

  1. A Density Functional Study of Bare and Hydrogenated Platinum Clusters

    CERN Document Server

    Sebetci, A

    2006-01-01

    We perform density functional theory calculations using Gaussian atomic-orbital methods within the generalized gradient approximation for the exchange and correlation to study the interactions in the bare and hydrogenated platinum clusters. The minimum-energy structures, binding energies, relative stabilities, vibrational frequencies and the highest occupied and lowest unoccupied molecular-orbital gaps of Pt_nH_m (n=1-5, m=0-2) clusters are calculated and compared with previously studied pure platinum and hydrogenated platinum clusters. We investigate any magic behavior in hydrogenated platinum clusters and find that Pt_4H_2 is more stable than its neighboring sizes. Our results do not agree with a previous conclusion that 3D geometries of Pt tetramer and pentamer are unfavored. On the contrary, the lowest energy structure of Pt_4 is found to be a distorted tetrahedron and that of Pt_5 is found to be a bridge site capped tetrahedron which is a new global minimum for Pt_5 cluster. The successive addition of H ...

  2. AMQ Protocol Based Performance Analysis of Bare Metal Hypervisors

    Directory of Open Access Journals (Sweden)

    Dr Deepak Arora

    2014-06-01

    Full Text Available Cloud computing is one of the most exciting technology because of its cost-reducing approach, flexibility, and scalability. Hypervisor is the essential part of cloud technology; it is a component of software that provides a virtualized hardware environment to support running multiple operating systems concurrently using one physical server. In this paper we took KVM, XEN, Hyper-V and ESXi as hypervisors. We have compared the performance of Virtual Machines (VMs by RabbitMQ message broker server that uses Advanced Message Queuing Protocol(AMQP for breaking messages. We establish the setup on bare metal hypervisor that is installed directly on the hardware of the system. We took SAN (Shared Storage Network server for maintaining the storage of all VMs. By the evaluation of these hyperviosrs we got a brief idea about their performance on different parameters. These results will be beneficial to small enterprise, social group or any private IT firm which is choosing to build small cloud infrastructure with optimal benefits. Experiment results of checking the performance of VMs for all the hypervisors shows that there is performance variation on different applications and workloads of the hypervisors. None of the hypervisors outperform another at every aspect of our comparison.

  3. Late thrombosis of coronary bare-metal stent: Case report

    Directory of Open Access Journals (Sweden)

    Apostolović Svetlana

    2006-01-01

    Full Text Available Stent thrombosis remains the primary cause of death after percutaneous coronary interventions (PCI. Despite modern concepts of PCI, stent thrombosis occurs in 0.5% -2% of elective procedures and even 6% of patients with the acute coronary syndrome (ACS. Stent thrombosis most often develops within the first 48 hours after the PCI, and rarely after a week of stent implantation. Angiographically documented late (>6 months thrombosis of coronary bare-metal stent (BMS is rare, because the stent endothelialization is considered to be completed after four weeks of the intervention. Our patient is a 41 year old male and he had BMS thrombosis 345 days after the implantation, which was clinically manifested as an acute myocardial infarction in the inferoposterolateral localization. Stent Clinical Centre of Serbia, Belgrade thrombosis occurred despite a long term dual antiplatelet therapy and control of known risk factors. Thrombolytic therapy (Streptokinase in a dose of 1 500 000 IU was not successful in reopening the occluded vessel, so the flow through the coronary artery was achieved by rescue balloon angioplasty, followed by implantation of drug eluting stent in order to prevent restenosis.

  4. Electron capture by bare ions on water molecules

    Science.gov (United States)

    Rivarola, Roberto; Montenegro, Pablo; Monti, Juan; Fojón, Omar

    2016-05-01

    Single electron capture from water molecules by impact of bare ions is theoretically investigated at intermediate and high collision energies. This reaction is of fundamental importance to determine the deposition of energy in biological matter irradiated with ion beams (hadrontherapy), dominating other ionizing processes of the target at low-intermediate impact velocities and giving principal contributions to the energetic region where electronic stopping power maximizes. The dynamics of the interaction between the aggregates is described within the one active-electron continuum distorted wave-eikonal initial state theory. The orbitals of the target in the ground state are represented using the approximate self-consistent complete neglect of differential orbitals (SC-CNDO) model. The contribution of different molecular orbitals on the partial cross sections to selected n-principal quantum number projectile states is discriminated as well as the collaboration of these n-states on total cross sections. The latter ones are dominated by capture to n=1 states at high enough energies decreasing their contribution as n increases.

  5. Fortissimo: A Japanese Space Test Of Bare Wire Anode Tethers

    Science.gov (United States)

    Johnson, Les; Fujii, H. A.; Sanmartin, J. R.

    2008-01-01

    A Japanese led international team is developing a suborbital test of orbital-motion-limited (OML) bare wire anode current collection for application to electrodynamic tether (EDT) propulsion. The tether is a tape with a width of 25 mm, thickness of 0.05 mm, and is 300 m in length. This will be the first space test of OML theory. The mission will launch in the summer of 2009 using an S520 Sounding Rocket. During ascent, and above approx. 100 km in attitude, the tape tether will be deployed at a rate of approx. 8 m/s. Once deployed, the tape tether will serve as an anode, collecting ionospheric electrons. The electrons will be expelled into space by a hollow cathode device, thereby completing the circuit and allowing current to flow. The total amount of current collected will be used to assess the validity of OML theory. This paper will describe the objectives of the proposed mission, the technologies to be employed, and the application of the results to future space missions using EDTs for propulsion or power generation.

  6. Analysis of thermionic bare tether operation regimes in passive mode

    Science.gov (United States)

    Sanmartín, J. R.; Chen, Xin; Sánchez-Arriaga, G.

    2017-01-01

    A thermionic bare tether (TBT) is a long conductor coated with a low work-function material. In drag mode, a tether segment extending from anodic end A to a zero-bias point B, with the standard Orbital-motion-limited current collection, is followed by a complex cathodic segment. In general, as bias becomes more negative in moving from B to cathodic end C, one first finds space-charge-limited (SCL) emission covering up to some intermediate point B*, then full Richardson-Dushman (RD) emission reaching from B* to end C. An approximate analytical study, which combines the current and voltage profile equations with results from asymptotic studies of the Vlasov-Poisson system for emissive probes, is carried out to determine the parameter domain covering two limit regimes, which are effectively controlled by just two dimensionless parameters involving ambient plasma and TBT material properties. In one such limit regime, no point B* is reached and thus no full RD emission develops. In an opposite regime, SCL segment BB* is too short to contribute significantly to the current balance.

  7. Effect of soil property on evaporation from bare soils

    Science.gov (United States)

    Zhang, Chenming; Li, Ling; Lockington, David

    2015-04-01

    Quantifying the actual evaporation rate from bare soils remains a challenging task as it not only associates with the atmospheric demand and liquid water saturation on the soil surface, but also the properties of the soils (e.g., porosity, pore size distribution). A physically based analytical model was developed to describe the surface resistance varying with the liquid water saturation near the soil surface. This model considers the soil pore size distribution, hydraulic connection between the main water cluster and capillary water in the soil surface when the soil surface is wet and the thickness of the dry soil layer when the soil surface is dry. The surface resistance model was then integrated to a numerical model based on water balance, heat balance and surface energy balance equations. The integrated model was validated by simulating water and heat transport processes during six soil column drying experiments. The analysis indicates that the when soil surface is wet, the consideration of pore size distribution in the surface resistance model offers better estimation of transient evaporation among different soil types than the estimations given by empirically based surface resistance models. Under fixed atmospheric boundary condition and liquid water saturation, fine sand has greater evaporation rate than coarse sand as stronger capillary force devlivers more water from the main water cluster. When the soil surface becomes dry, the impact of soil property to evaporation becomes trivial as the thickness of the dry soil layer turns to be the key factor to determine the evaporation rate.

  8. Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings▿†

    Science.gov (United States)

    Hur, Moonsuk; Kim, Yongho; Song, Hae-Ryong; Kim, Jong Min; Choi, Young Im; Yi, Hana

    2011-01-01

    The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizosphere of genetically modified (GM) versus wild-type (WT) poplar was conducted on trees at different growth stages (i.e., the rhizospheres of 1.5-, 2.5-, and 3-year-old poplars) that were cultivated on contaminated soils together with nonplanted control soil. Based on the results of DNA pyrosequencing, poplar type and growth stages were associated with directional changes in the structure of the microbial community. The rate of change was faster in GM poplars than in WT poplars, but the microbial communities were identical in the 3-year-old poplars. This phenomenon may arise because of a higher rate and greater extent of metal accumulation in GM poplars than in naturally occurring plants, which resulted in greater changes in soil environments and hence the microbial habitat. PMID:21890678

  9. Effect of Barely flour on jaundice in full-term neonates

    Directory of Open Access Journals (Sweden)

    azam Mohsenzadeh

    2005-08-01

    Conclusions: Our study indicated that phototherapy in conjuction with barely flour therapy is more effective than phototherapy alone. But, people must be informed that affected neonates have to be underwent medical therapy, and barely flour therapy alone is not a reliable treatment.

  10. Association analysis identifies Melampsora ×columbiana poplar leaf rust resistance SNPs.

    Directory of Open Access Journals (Sweden)

    Jonathan La Mantia

    Full Text Available Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05 with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca²⁺/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism.

  11. Effects of Direct Application of Fertilizers and Hydrogel on the Establishment of Poplar Cuttings

    Directory of Open Access Journals (Sweden)

    Henrik Böhlenius

    2014-12-01

    Full Text Available The aim of poplar plantations is to achieve high biomass production over a short rotation period. This requires low mortality and fast development of the transplants. The experiment described in this paper examines methods aimed at enhancing survival and development of Populus trichocarpa plants by application of fertilizers, a hydrogel or a combination of both to dormant cuttings just before planting. The experiment was carried out at two agricultural sites with different soil characteristics, a loamy sand and a silty loam. It was demonstrated that none of the treatments influenced survival or early growth at the silty loam soil site, and plant development was delayed by the solid fertilizer. At the site with loamy sand, the solid fertilizer negatively affected both survival and early growth. Hydrogel and the combination of hydrogel and the solid fertilizer also hampered early growth. Overall, treatments of poplar cuttings with hydrogel or fertilizers alone, or in combination, may not be a method to reduce poplar cutting mortality or to enhance early plant development on agricultural land. However, our results demonstrate that establishing poplar with cuttings as transplants can be used on both loamy sand and silty loam soils.

  12. Soil respiration in apple orchards, poplar plantations and adjacent grasslands in Artvin, Turkey.

    Science.gov (United States)

    Tufekcioglu, Aydin; Ozbayram, Ali Kemal; Kucuk, Mehmet

    2009-09-01

    In this study influence of land-use type on soil respiration was investigated in poplar plantation, apple orchard (apple trees with understory grasses) and adjacent grassland sites in Seyitler Area, Artvin, Turkey. Soil respiration was measured approximately monthly in three sampling plots in each land use type from January 2005 to November 2005 using the soda-lime technique. Mean daily soil respiration ranged from 0.63-3.59 g Cm(-2) d(-1). Mean soil respiration in apple orchard, poplar plantation and grassland sites were 1.98, 1.45 and 1.12 g C m(-2) d(-1), respectively. Mean soil respiration was significantly greater in apple orchard than in poplar plantations and grasslands. Seasonal changes in soil respiration were related to soil moisture and temperature changes. Mean soil respiration rate correlated strongly with subsurface soil (15-35cm) pH (R = -0,73; p biomass. Overall, our results indicate that apple orchards with understory grasses have higher soil biological activity compared to poplar and grassland sites.

  13. Environmental controls on ozone fluxes in a poplar plantation in Western Europe

    DEFF Research Database (Denmark)

    Zona, D.; Gioli, B.; Fares, S.

    2014-01-01

    Tropospheric O-3 is a strong oxidant that may affect vegetation and human health. Here we report on the O-3 fluxes from a poplar plantation in Belgium during one year. Surprisingly, the winter and autumn O-3 fluxes were of similar magnitude to ones observed during most of the peak vegetation deve...

  14. The use of short rotation willows and poplars for the recycling of saline waste waters

    Science.gov (United States)

    Jaconette Mirck; Ronald S. Jr. Zalesny; Ioannis Dimitriou; Jill A. Zalesny; Timothy A. Volk; Warren E. Mabee

    2009-01-01

    The production of high-salinity waste waters by landfills and other waste sites causes environmental concerns. This waste water often contains high concentrations of sodium and chloride, which may end up in local ground and surface waters. Vegetation filter systems comprised of willows and poplars can be used for the recycling of saline waste water. These vegetation...

  15. Poplar trees for phytoremediation of high levels of nitrate and applications in bioenergy.

    Science.gov (United States)

    Castro-Rodríguez, Vanessa; García-Gutiérrez, Angel; Canales, Javier; Cañas, Rafael A; Kirby, Edward G; Avila, Concepción; Cánovas, Francisco M

    2016-01-01

    The utilization of high amounts of nitrate fertilizers for crop yield leads to nitrate pollution of ground and surface waters. In this study, we report the assimilation and utilization of nitrate luxuriant levels, 20 times more than the highest N fertilizer application in Europe, by transgenic poplars overexpressing a cytosolic glutamine synthetase (GS1). In comparison with the wild-type controls, transgenic plants grown under high N levels exhibited increased biomass (171.6%) and accumulated higher levels of proteins, chlorophylls and total sugars such as glucose, fructose and sucrose. These plants also exhibited greater nitrogen-use efficiency particularly in young leaves, suggesting that they are able to translocate most of the resources to the above-ground part of the plant to produce biomass. The transgenic poplar transcriptome was greatly affected in response to N availability with 1237 genes differentially regulated in high N, while only 632 genes were differentially expressed in untransformed plants. Many of these genes are essential in the adaptation and response against N excess and include those involved in photosynthesis, cell wall formation and phenylpropanoid biosynthesis. Cellulose production in the transgenic plants was fivefold higher than in control plants, indicating that transgenic poplars represent a potential feedstock for applications in bioenergy. In conclusion, our results show that GS transgenic poplars can be used not only for improving growth and biomass production but also as an important resource for potential phytoremediation of nitrate pollution.

  16. Identification of differentially expressed proteins in poplar leaves induced by Marssonina brunnea f. Sp. Multigermtubi

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Black spot disease in poplar is a disease of the leaf caused by fungus. The major pathogen is Marssonina brunnea f. sp. multigermtubi.To date, little is known about the molecular mechanism of poplar (M. brunnea) interaction. In order to identify the proteins related to disease resistance and understand its molecular basis, the clone "NL895" (P. euramericana CL"NL895"), which is highly resistant to M.brunnea f. sp. multigermtubi, was used in this study. We used two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to identify the proteins in poplar leaves that were differentially expressed in response to black spot disease pathogen, M. brunnea f. sp. multigermtubi. Proteins extracted from poplar leaves at 0, 12, 24, 48, and 72 h after pathogen-inoculation were separated by 2-DE. About 500 reproducible protein spots were detected, of which 40 protein spots displayed differential expression in levels and were subjected to Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) followed by database searching. According to the function, the identified proteins were sorted into five categories, that is, protein synthesis, metabolism, defense response and unclassified proteins.

  17. Effector-mining in the poplar rust fungus Melampsora larici populina secretome

    Directory of Open Access Journals (Sweden)

    Cecile eLorrain

    2015-12-01

    Full Text Available The poplar leaf rust fungus, Melampsora larici-populina has been established as a tree-microbe interaction model. Understanding the molecular mechanisms controlling infection by pathogens appears essential for durable management of tree plantations. In biotrophic plant parasites, effectors are known to condition host cell colonization. Thus, investigation of candidate secreted effector proteins is a major goal in the poplar-poplar rust interaction. Unlike oomycetes, fungal effectors do not share conserved motifs and candidate prediction relies on a set of a priori criteria established from reported bona fide effectors. Secretome prediction, genome-wide analysis of gene families and transcriptomics of M. larici-populina have led to catalogues of more than a thousand secreted proteins. Automatized effector mining pipelines hold great promise for rapid and systematic identification and prioritization of candidate secreted effector proteins for functional characterization. In this review, we report on and discuss the current status of the poplar rust fungus secretome and prediction of candidate effectors in this species.

  18. Arbuscular mycorrhizal fungi differentially affect the response to high zinc concentrations of two registered poplar clones

    Energy Technology Data Exchange (ETDEWEB)

    Lingua, Guido [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy)], E-mail: guido.lingua@mfn.unipmn.it; Franchin, Cinzia [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Todeschini, Valeria [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy); Castiglione, Stefano [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Biondi, Stefania [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Burlando, Bruno [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy); Parravicini, Valerio [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Torrigiani, Patrizia [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Berta, Graziella [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy)

    2008-05-15

    The effects of a high concentration of zinc on two registered clones of poplar (Populus alba Villafranca and Populus nigra Jean Pourtet), inoculated or not with two arbuscular mycorrhizal fungi (Glomus mosseae or Glomus intraradices) before transplanting them into polluted soil, were investigated, with special regard to the extent of root colonization by the fungi, plant growth, metal accumulation in the different plant organs, and leaf polyamine concentration. Zinc accumulation was lower in Jean Pourtet than in Villafranca poplars, and it was mainly translocated to the leaves; the metal inhibited mycorrhizal colonization, compromised plant growth, and, in Villafranca, altered the putrescine profile in the leaves. Most of these effects were reversed or reduced in plants pre-inoculated with G. mosseae. Results indicate that poplars are suitable for phytoremediation purposes, confirming that mycorrhizal fungi can be useful for phytoremediation, and underscore the importance of appropriate combinations of plant genotypes and fungal symbionts. - Inoculation with arbuscular mycorrhizal fungi can improve poplar tolerance to heavy metals in phytoremediation programmes.

  19. Energy partitioning and surface resistance of a poplar plantation in northern China

    Science.gov (United States)

    M. Kang; Z. Zhang; A. Noormets; X. Fang; T. Zha; J. Zhou; G. Sun; S. G. McNulty; J. Chen

    2015-01-01

    Poplar (Populus sp.) plantations have been, on the one hand, broadly used in northern China for urban greening, combating desertification, as well as for paper and wood production. On the other hand, such plantations have been questioned occasionally for their possible negative impacts on water availability due to the higher water-use nature of...

  20. Genetic manipulation of the metabolism of polyamines in poplar cells. The regulation of putrescine catabolism

    Science.gov (United States)

    Pratiksha Bhatnagar; Rakesh Minocha; Subhash C. Minocha

    2002-01-01

    We investigated the catabolism of putrescine (Put) in a non-transgenic (NT) and a transgenic cell line of poplar (Populus nigra x maximowiczii) expressing a mouse (Mus musculus) ornithine (Orn) decarboxylase (odc) cDNA. The transgenic cells produce 3- to 4-fold higher amounts of Put than the NT...

  1. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.

    Science.gov (United States)

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-02-23

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement.

  2. Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure.

    Science.gov (United States)

    Barrès, Benoît; Dutech, Cyril; Andrieux, Axelle; Halkett, Fabien; Frey, Pascal

    2012-10-01

    Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungus Melampsora larici-populina using a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analysed using nine microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). Moreover, we observed an erosion of clonal structure through time, with an increase in both gene and genotypic diversity. New genotypes contributed to host infection over time, which demonstrates the importance of allo-infection in the epidemic process in this host-pathogen system. Compared with the wild stands, the nearly lack of detection of clonal structure in the cultivated stands reflects the higher infection level on cultivated poplars. More generally, this genetic analysis illustrates the utility of population genetics approach for elucidating the proportion of asexual reproduction in the multiplication of isolates during an epidemic, and for proper quantification of asexual dispersal in plant pathogens.

  3. Phytotoxicity of fresh and weathered diesel and gasoline to willow and poplar trees

    DEFF Research Database (Denmark)

    Trapp, Stefan; Köhler, A.; Larsen, L.C.

    2001-01-01

    The toxicity of fresh and weathered gasoline and diesel fuel to willow and poplar trees was studied using a tree transpiration toxicity test. Soils were taken from an abandoned filling station. Concentrations in the samples were measured as the sum of hydrocarbons from C5 to C10 (gasoline) and C1...

  4. Hydrodynamic behavior of a bare rod bundle. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Bartzis, J.G.; Todreas, N.E.

    1977-06-01

    The temperature distribution within the rod bundle of a nuclear reactor is of major importance in nuclear reactor design. However temperature information presupposes knowledge of the hydrodynamic behavior of the coolant which is the most difficult part of the problem due to complexity of the turbulence phenomena. In the present work a 2-equation turbulence model--a strong candidate for analyzing actual three dimensional turbulent flows--has been used to predict fully developed flow of infinite bare rod bundle of various aspect ratios (P/D). The model has been modified to take into account anisotropic effects of eddy viscosity. Secondary flow calculations have been also performed although the model seems to be too rough to predict the secondary flow correctly. Heat transfer calculations have been performed to confirm the importance of anisotropic viscosity in temperature predictions. All numerical calculations for flow and heat have been performed by two computer codes based on the TEACH code. Experimental measurements of the distribution of axial velocity, turbulent axial velocity, turbulent kinetic energy and radial Reynolds stresses were performed in the developing and fully developed regions. A 2-channel Laser Doppler Anemometer working on the Reference mode with forward scattering was used to perform the measurements in a simulated interior subchannel of a triangular rod array with P/D = 1.124. Comparisons between the analytical results and the results of this experiment as well as other experimental data in rod bundle array available in literature are presented. The predictions are in good agreement with the results for the high Reynolds numbers.

  5. Sense and nonsense of bare metal stents below the knee.

    Science.gov (United States)

    Caradu, Caroline; Brizzi, Vincenzo; Auque, Heloise; Midy, Dominique; Ducasse, Eric

    2016-10-01

    Critical limb ischemia (CLI) is increasingly present in daily practice, and diabetes is responsible for a preferential below the knee (BTK) localization of the disease. The objective was to determine if there is still a sense to BTK implantation of bare metal stents (BMSs) in CLI patients in the era of drug eluting strategies. An extensive review of the literature was carried out over the last 15 years on the use of BMSs in BTK revascularization based on a PubMed (Medline), EMBASE and PubMed Central search. The Chromis Deep® (Invatec, Roncadelle, Italy) was the first dedicated stent in BTK lesions, followed by passive coated BMSs developed in an attempt to inhibit platelets deposition. Comparative results showed no advantage of primary BMS implantation over peripheral transluminal angioplasty (PTA) in improving primary patency rates, Rutherford classification or wound healing and the place of BMSs was restricted to bailout spot stenting. The fear of patency loss in connection with possible stent fractures led to an interest towards nitinol stents, but results were disappointing, especially in patients with severely calcified lesions. Drug-eluting stents (DESs) were then developed and showed better long-term primary patency, restenosis and freedom from target lesion revascularization (TLR) rates, even in long calcified lesions against BMS or drug eluting balloons (DEB). However, limb salvage and wound healing rates were not significantly improved. Primary BMS implantation showed no advantage over PTA and as of today DES trials have not shown enough clinical or economic benefit. Thus, BMSs are recommended over DESs, and only as a bailout strategy in case of flow limiting dissection or recoil. Quality trials assessing long-term clinically relevant outcomes, evolution in stents designs and vessel preparation could lead to a change in those recommendations.

  6. Wutun Poplar growth in South of Xinjiang%吴屯杨在南疆的生长状况研究

    Institute of Scientific and Technical Information of China (English)

    丁晓丽; 易海艳; 杨盼盼

    2015-01-01

    Determination of annual Xinjiang poplar Wutun poplar under the same conditions, the growth indica-tors, the results show that the Wutun poplar implanted in 4436, 342 died, Wutun poplar's survival rate was 92.3%, while Xinjiang poplar implanted in 4399, 513 died, Xinjiang poplar survival rate was 88.3%.Through the investi-gation of Wutun poplar, and Xinjiang poplar plant height, diameter, diameter at breast height and found that Wutun poplar both plant height, basal diameter, diameter at breast height of these growth indicators are excellent and the Xinjiang poplar, so it can be concluded in the same habitatunder Wutun poplar faster than Xinjiang poplar growth rate, the overall growth is relatively stable, the resistance of fast-growing Wutun poplar introduction to the southern border is feasible.%通过对一年生的新疆杨与吴屯杨在同一条件下的生长指标测定,结果表明,吴屯杨共植入4436株,死亡342株,吴屯杨的成活率为92.3%;而新疆杨共植入4399株,死亡513株,新疆杨的成活率为88.3%.通过调查吴屯杨和新疆杨的株高、地径、胸径,发现吴屯杨无论是株高、地径、胸径这些生长指标都优与新疆杨,因此在同一生境下吴屯杨比新疆杨生长速率更快,整体生长比较稳定,抗逆性速生吴屯杨引种至南疆具有可行性.

  7. Abaxial Greening Phenotype in Hybrid Aspen

    Directory of Open Access Journals (Sweden)

    Julia S. Nowak

    2013-04-01

    Full Text Available The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial and bottom (abaxial surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively. Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the “abaxial greening” phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1 as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa and hybrid aspen (P. tremula x tremuloides, representative of each leaf type (bifacial and isobilateral, respectively. Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening.

  8. Abaxial Greening Phenotype in Hybrid Aspen.

    Science.gov (United States)

    Nowak, Julia S; Douglas, Carl J; Cronk, Quentin C B

    2013-04-24

    The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial) and bottom (abaxial) surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively). Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the "abaxial greening" phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1) as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all) putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa) and hybrid aspen (P. tremula x tremuloides), representative of each leaf type (bifacial and isobilateral, respectively). Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS) ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening.

  9. [The bare area of the proximal ulna : An anatomical study on optimizing olecranon osteotomy].

    Science.gov (United States)

    Hackl, M; Lappen, S; Neiss, W F; Scaal, M; Müller, L P; Wegmann, K

    2016-10-01

    Olecranon osteotomy is an established approach for the treatment of distal humerus fractures. It should be performed through the bare area of the proximal ulna to avoid iatrogenic cartilage lesions. The goal of this study was to analyze the anatomy of the proximal ulna with regard to the bare area and, thereby, to optimize the hitting area of the bare area when performing olecranon osteotomy. The bare areas of 30 embalmed forearm specimens were marked with a radiopaque wire and visualized three-dimensionally with a mobile C‑arm. By means of 3D reconstructions of the data sets, the following measurements were obtained: height of the bare area; span of the bare area-hitting area in transverse osteotomy; ideal angle for olecranon osteotomy to maximize the hitting area of the bare area; distance of the posterior olecranon tip to the entry point of the transverse osteotomy and the ideal osteotomy. The height of the bare area was 4.92 ± 0.81 mm. The hitting area of the transverse osteotomy averaged 3.73 ± 0.89 mm. The "ideal" angle for olecranon osteotomy was 30.7° ± 4.19°. The distance of the posterior olecranon tip to the entry point was 14.08 ± 2.75 mm for the transverse osteotomy and 24.21 ± 3.15 mm for the ideal osteotomy. The hitting area of the bare area in the ideal osteotomy was enhanced significantly when compared to the transverse osteotomy (p osteotomy of the olecranon. Moreover, a 30° angulation of the osteotomy can significantly increase the hitting area of the bare area.

  10. Biomass productivity and water use relation in short rotation poplar coppice (Populus nigra x P. maximowiczii in the conditions of Czech Moravian Highlands

    Directory of Open Access Journals (Sweden)

    Milan Fischer

    2011-01-01

    Full Text Available The plantations of short rotation coppice (SRC usually based on poplar or willow species are promising source of biomass for energy use. To contribute to decision-making process where to establish the plantations we evaluated the water consumption and its relation to biomass yields of poplar hybrid clone J-105 (Populus nigra x P. maximowiczii in representative conditions for Czech-Moravian Highlands. Water availability is usually considered as one of the main constraints of profitable SRC culture and therefore we focused on analyzing of the linkage between the aboveground biomass increments and the total stand actual evapotranspiration (ETa and on water use efficiency of production (WUEP. During the seasons 2008 and 2009 the total stand ETa measured by Bowen ratio energy balance system constructed above poplar canopy and the stem diameter increments of randomly chosen sample trees were examined. The stem diameters were subsequently converted to total aboveground biomass (AB by allometric equation obtained by destructive analysis at the beginning of 2010. The biomass volume and its increment of particular trees were subsequently converted to the whole canopy growth and correlated with the ETa values. Our results revealed that there was a statistically significant relation between water lost and biomass growth with coefficients of determination r2 0.96 and 0.51 in 2008 and 2009 respectively. By using multiple linear regression analysis additionally accounting for effect of precipitation events and thermal time (sums of effective temperatures above +5 °C the AB growth was explained from 98 and 87% in 2008 and 2009, respectively. Therefore for further analysis the multiple linear regression model was applied. The dynamic of seasonal WUEP (expressed as gram of AB dry matter per thousand grams of water reached up to 6.2 and 6.8 g kg−1 with means 3.13 and 3.54 g kg−1 in both executed years respectively. These values are situated in higher

  11. Responses of energy partitioning and surface resistance to drought in a poplar plantation in northern China

    Science.gov (United States)

    Kang, M.; Zhang, Z.; Noormets, A.; Fang, X.; Zha, T.; Zhou, J.; Sun, G.; McNulty, S.; Chen, J.

    2015-01-01

    Poplar (Populus sp.) plantations have been used broadly for combating desertification, urban greening, and paper and wood production in northern China. However, given the high water use by the species and the regional dry environment, the long-term sustainability of these plantations needs to be evaluated. Currently, the understanding of energy partitioning and canopy resistance to water vapor and CO2 in poplar plantations is limited, impeding an accurate assessment of their true ecosystem functions. This study examined the variability of canopy bulk resistance parameters and energy partitioning over a four-year period encompassing both dry and wet conditions in a poplar (Populus euramericana CV. "74 / 76") plantation ecosystem located in northern China. Available energy (Net radiation Rn minus Soil Heat Flux, G) partitioning to latent (LE) and sensible (H) heat was responsive to climatological drought, with LE/(Rn-G) ranging from 62% in wet years (e.g. 2007 and 2008) to 53% in dry years (e.g. 2006 and 2009), and H/(Rn-G) from 25 to 33% between wet and dry years. Correspondingly, the Bowen ratio (β=H/LE) were 0.83 and 1.57. Surface resistance (Rs) had the greatest response to drought (+43%), but the aerodynamic and climatological resistances did not change significantly (p > 0.05). Partial correlation analysis indicated that Rs was the dominant factor in controlling the Bowen ratio. Furthermore, Rs was the major factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively), and the LE / LEeq ratio ranged from 0.81 and 0.68 in wet and dry years, respectively. In general, the dry surface conditions dominated in this poplar plantation ecosystem regardless of soil water availability suggesting that fast-growing and water use-intensive species like poplar plantations are poorly adapted for the water limited region.

  12. Responses of energy partitioning and surface resistance to drought in a poplar plantation in northern China

    Directory of Open Access Journals (Sweden)

    M. Kang

    2015-01-01

    Full Text Available Poplar (Populus sp. plantations have been used broadly for combating desertification, urban greening, and paper and wood production in northern China. However, given the high water use by the species and the regional dry environment, the long-term sustainability of these plantations needs to be evaluated. Currently, the understanding of energy partitioning and canopy resistance to water vapor and CO2 in poplar plantations is limited, impeding an accurate assessment of their true ecosystem functions. This study examined the variability of canopy bulk resistance parameters and energy partitioning over a four-year period encompassing both dry and wet conditions in a poplar (Populus euramericana CV. "74 / 76" plantation ecosystem located in northern China. Available energy (Net radiation Rn minus Soil Heat Flux, G partitioning to latent (LE and sensible (H heat was responsive to climatological drought, with LE/(Rn-G ranging from 62% in wet years (e.g. 2007 and 2008 to 53% in dry years (e.g. 2006 and 2009, and H/(Rn-G from 25 to 33% between wet and dry years. Correspondingly, the Bowen ratio (β=H/LE were 0.83 and 1.57. Surface resistance (Rs had the greatest response to drought (+43%, but the aerodynamic and climatological resistances did not change significantly (p > 0.05. Partial correlation analysis indicated that Rs was the dominant factor in controlling the Bowen ratio. Furthermore, Rs was the major factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively, and the LE / LEeq ratio ranged from 0.81 and 0.68 in wet and dry years, respectively. In general, the dry surface conditions dominated in this poplar plantation ecosystem regardless of soil water availability suggesting that fast-growing and water use-intensive species like poplar plantations are poorly adapted for the water limited region.

  13. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level

    National Research Council Canada - National Science Library

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-01-01

    ...) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground...

  14. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  15. Clinical and angiographic outcomes after intracoronary bare-metal stenting.

    Directory of Open Access Journals (Sweden)

    I-Chang Hsieh

    Full Text Available BACKGROUND: Data from a large patient population regarding very long-term outcomes after BMS implantation are inadequate. This study aimed to evaluate the very long-term (8-17 years clinical and long-term (3-5 years angiographic outcomes after intracoronary bare-metal stenting (BMS. METHODS AND RESULTS: From the Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions (CAPTAIN registry, a total of 2391 patients with 2966 lesions treated with 3190 BMSs between November 1995 and May 2004 were evaluated. In total, 1898 patients with 2364 lesions, and 699 patients with 861 lesions underwent 6-month and 3- to 5- year angiographic follow-up, respectively. During a mean follow-up period of 149 ± 51 months, 18.6% of the patients died (including 10.8% due to cardiac death, 6.1% developed reinfarction, 16.2% had target lesion revascularization (including 81% of the patients within the first year, 14.5% underwent new lesion stenting (including 72% of the patients after 3 years, 2.4% underwent coronary bypass surgery, and 1.6% had definite stent thrombosis. The overall cardiovascular event-free survival rate was 58.5%. The 6-month angiographic study indicated a 20% restenosis rate. The minimal luminal diameter increased from 0.65 ± 0.44 mm to 3.02 ± 0.46 mm immediately after stenting, decreased to 2.06 ± 0.77 mm at the 6-month follow-up, and increased to 2.27 ± 0.68 mm at the 3- to 5-year follow-up. CONCLUSIONS: This study provides clinical and angiographic results from a large population of patients who underwent BMS implantations after a long-term follow-up period (149 ± 51 months. The progression of coronary atherosclerosis developed over time, and presented with new lesion required stent implantation. The follow-up angiographic findings reconfirmed the late and sustained improvement in luminal diameter between 6 months and 3-5 years.

  16. Nuda vida y goce. // Bare life and jouissance.

    Directory of Open Access Journals (Sweden)

    Laura Arias.

    2010-06-01

    Full Text Available From the point of view that connects politics and psychoanalysis, the aim of this essay is to investigate the causes of the annihilation of the subject in the totalitarian regimes, making him a victim of power, reduced to a bare life. This question leads us to analyze the jouissance within the frame of a regime that proposes the unification of a universal jouissance. These questions are considered to be relevant in the field that makes possible the intersection between politics and subjectivity. The direct proposal of this essay is related to thought, by trying to bring thought into play, in conjunction with the concepts of jouissance and the annihilation of the subject in the totalitarian regimes. It deals with the articulation between thought and jouissance and uses these ideas like conceptual tools, with the aim of considering the subjectivity of the time. // Desde el punto de vista que relaciona la política con el psicoanálisis, la propuesta de este ensayo trata de interrogar qué produce la aniquilación del sujeto en los regímenes totalitarios, al convertirlo en víctimas del poder, reducido a nuda vida. Este cuestionamiento nos conduce a preguntarnos sobre el goce en el marco de un régimen que propone la unificación de un goce universal. Consideramos pertinentes estos cuestionamientos en la vertiente que posibilita el cruce entre política y subjetividad. La propuesta expresa de este ensayo se relaciona con el pensar; con la posibilidad de recuperar una reflexión sobre el pensar, tratando de ponerlo en escena, en conjunción con el goce y la aniquilación del sujeto en los regímenes totalitarios. Se trata de una articulación entre pensar y goce y toma estas nociones como herramientas conceptuales, en el interés por considerar la subjetividad de la época.

  17. Evaluation of interspecific DNA variability in poplars using AFLP and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... markers. The AFLP and SSR markers polymorphism and its power of discrimination were determined ... clones, cultivars and hybrids on molecular basis. .... Means for SSR DNA variability and informative parameters over the 13 SSR loci for ... specific range, number of monomorphic and polymorphic bands ...

  18. Analyzing the impact of climate and management factors on the productivity and soil carbon sequestration of poplar plantations.

    Science.gov (United States)

    Wang, Dan; Fan, Jiazhi; Jing, Panpan; Cheng, Yong; Ruan, Honghua

    2016-01-01

    It is crucial to investigate how climate and management factors impact poplar plantation production and soil carbon sequestration interactively. We extracted above-ground net primary production (ANPP), climate and management factors from peer-reviewed journal articles and analyzed impact of management factor and climate on the mean annual increment (MAI) of poplar ANPP statistically. Previously validated mechanistic model (ED) is used to perform case simulations for managed poplar plantations under different harvesting rotations. The meta-analysis indicate that the dry matter MAI was 6.3 Mg ha(-1) yr(-1) (n=641, sd=4.9) globally, and 5.1 (n=292, sd=4.0), 8.1 (n=224, sd=4.7) and 4.4 Mg ha(-1) yr(-1) (n=125, sd=3.2) in Europe, the US and China, respectively. Poplar MAI showed a significant response to GDD, precipitation and planting density and formed a quadratic relationship with stand age. The low annual production for poplar globally was probably caused by suboptimal water availability, rotation length and planting density. SEM attributes the variance of poplar growth rate more to climate than to management effects. Case simulations indicated that longer rotation cycle significantly increased soil carbon storage. Findings of this work suggests that management factor of rotation cycle alone could have dramatic impact on the above ground growth, as well as on the soil carbon sequestration of poplar plantations and will be helpful to quantify the long-term carbon sequestration through short rotation plantation. The findings of this study are useful in guiding further research, policy and management decisions towards sustainable poplar plantations. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Bacterial microflora isolated from the bark surface of poplars growing in areas where air pollution is very high

    Directory of Open Access Journals (Sweden)

    Krystyna Przybył

    2015-05-01

    Full Text Available In the autumn of 1976 bacteria of the genera Bacillus, Pseudomonas, Flavobacterium, Erwinia and Cellulomonas were isolated from the bark surface of poplars growing in protective belts around several industrial plants. It was found that the qualitative and quantitative composition of the surface bacterial microflora changes in dependence on the degree of resistance of the poplars to the action of the dust emitted by the industrial establishment and containing high amounts of heavy metals.

  20. Impact of 40 years poplar cultivation on soil carbon stocks and greenhouse gas fluxes

    Directory of Open Access Journals (Sweden)

    C. Ferré

    2005-08-01

    Full Text Available Within the JRC Kyoto Experiment in the Regional Park and UN-Biosphere Reserve "Parco Ticino" (North-Italy, near Pavia, the soil carbon stocks and fluxes of CO2, N2O, and CH4 were measured in a poplar plantation in comparison with a natural mesohygrophilous deciduous forest nearby, which represents the pristine land cover of the area. Soil fluxes were measured using the static and dynamic closed chamber techniques for CH4 N2O, and CO2, respectively. We made further a pedological study to relate the spatial variability found with soil parameters.

    Annual emission fluxes of N2O and CO2 and deposition fluxes of CH4 were calculated for the year 2003 for the poplar plantation and compared to those measured at the natural forest site. N2O emissions at the poplar plantation were 0.15$plusmn;0.1 g N2O m-2 y-1 and the difference to the emissions at the natural forest of 0.07±0.06 g N2O m-2 y-1 are partly due to a period of high emissions after the flooding of the site at the end of 2002. CH4 consumption at the natural forest was twice as large as at the poplar plantation. In comparison to the relict forest, carbon stocks in the soil under the poplar plantation were depleted by 61% of surface (10 cm carbon and by 25% down the profile under tillage (45 cm. Soil respiration rates were not significant different at both sites with 1608±1053 and 2200±791 g CO2 m-2 y-1 at the poplar plantation and natural forest, respectively, indicating that soil organic carbon is much more stable in the natural forest. In terms of the greenhouse gas budget, the non-CO2 gases contributed minor to the overall soil balance with only 0.9% (N2O and -0.3% (CH4 of CO2-eq emissions in the

  1. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level

    Science.gov (United States)

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-09-01

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health.

  2. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level

    Science.gov (United States)

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-01-01

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health. PMID:27615148

  3. Epigenetic Diversity of Clonal White Poplar (Populus alba L. Populations: Could Methylation Support the Success of Vegetative Reproduction Strategy?

    Directory of Open Access Journals (Sweden)

    Francesco Guarino

    Full Text Available The widespread poplar populations of Sardinia are vegetatively propagated and live in different natural environments forming large monoclonal stands. The main goals of the present study were: i to investigate/measure the epigenetic diversity of the poplar populations by determining their DNA methylation status; ii to assess if and how methylation status influences population clustering; iii to shed light on the changes that occur in the epigenome of ramets of the same poplar clone. To these purposes, 83 white poplar trees were sampled at different locations on the island of Sardinia. Methylation sensitive amplified polymorphism analysis was carried out on the genomic DNA extracted from leaves at the same juvenile stage. The study showed that the genetic biodiversity of poplars is quite limited but it is counterbalanced by epigenetic inter-population molecular variability. The comparison between MspI and HpaII DNA fragmentation profiles revealed that environmental conditions strongly influence hemi-methylation of the inner cytosine. The variable epigenetic status of Sardinian white poplars revealed a decreased number of population clusters. Landscape genetics analyses clearly demonstrated that ramets of the same clone were differentially methylated in relation to their geographic position. Therefore, our data support the notion that studies on plant biodiversity should no longer be restricted to genetic aspects, especially in the case of vegetatively propagated plant species.

  4. 30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare..., and bare signal wires shall be adequately guarded: (a) At all points where men are required to work or...

  5. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. Trolley wires, trolley feeder wires, and bare signal wires shall be insulated...

  6. 2010 USGS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Chandeleur Islands, Louisiana (Bare-Earth)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the Chandeleur Islands, Louisiana, was produced from remotely...

  7. LiDAR Derived Bare Earth Digital Elevation Model: Camas National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset represents the Camas National Wildlife Refuge survey area in Jefferson and Clark County, ID. This bare earth digital elevation model (DEM) represent...

  8. LiDAR Derived Bare Earth Digital Elevation Model: Camas National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset represents the Camas National Wildlife Refuge survey area in Jefferson and Clark County, ID. This bare earth digital elevation model (DEM) represent the...

  9. EAARL Coastal Topography--Assateague Island National Seashore, 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth elevation map (also known as a Digital Elevation Model, or DEM) of the Assateague Island National Seashore in Virginia and Maryland was produced from...

  10. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  11. EAARL Coastal Topography--Western Florida, Post-Hurricane Charley, 2004: Seamless (Bare Earth and Submerged)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A seamless (bare-earth and submerged) elevation map (also known as a Digital Elevation Model, or DEM) of a portion of western Florida, post-Hurricane Charley, was...

  12. EAARL Coastal Topography--Assateague Island National Seashore, 2008: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth elevation map (also known as a Digital Elevation Model, or DEM) of the Assateague Island National Seashore in Virginia and Maryland was produced from...

  13. EAARL Coastal Topography--Assateague Island National Seashore, Maryland and Virginia, 2005: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Assateague Island National Seashore was produced from remotely sensed, geographically referenced...

  14. Galvanic effects on electrochemical behaviors of bare surface of 304 stainless steel

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The bare surface of 304 stainless steel is produced by the fast fracture method. The influence of the surfacegalvanic cell on the electrochemical behaviors of bare surface of 304 stainless steel has been investigated in H2SO4 solutionswith different concentrations. The results show that the solution corrosivity level and the area ratio influence the surfacegalvanic effects caused by the inhomogeneity between the free-film surface of alloy and the passive surface. The surfacegalvanic effects can speed up the dissolution rate of the bare surface of the alloy and will change the electrochemical behav-ior of bare surface. With the increase of the area ratio between passive surface and fractured surface, the galvanic potentialbecomes more positive and, in the range of passive potential, both galvanic current and the peak fracture current increase

  15. EAARL Coastal Topography--Western Florida, Post-Hurricane Charley, 2004: Seamless (Bare Earth and Submerged)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A seamless (bare-earth and submerged) elevation map (also known as a Digital Elevation Model, or DEM) of a portion of western Florida, post-Hurricane Charley, was...

  16. Assessing the adequacy of the bare optical potential in near-barrier fusion calculation

    Energy Technology Data Exchange (ETDEWEB)

    Canto, L.F. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, CP 68528, Rio de Janeiro (Brazil); Gomes, P.R.S.; Lubian, J. [Universidade Federal Fluminense, Instituto de Fisica, Niteroi, R.J. (Brazil); Hussein, M.S. [Universidade de Sao Paulo, Instituto de Estudos Avancados, C. P. 72012, Sao Paulo-SP (Brazil); Universidade de Sao Paulo, Instituto de Fisica, C. P. 66318, Sao Paulo (Brazil); Lotti, P. [INFN, Padova (Italy)

    2014-05-15

    We critically examine the differences among the different bare nuclear interactions used in near-barrier heavy-ion fusion analysis and coupled-channels calculations, and discuss the possibility of extracting the barrier parameters of the bare potential from above-barrier data. We show that the choice of the bare potential may be critical for the analysis of the fusion cross sections. Although this may seem trivial, several recent papers use different bare potentials and reach different conclusions, especially when weakly bound systems are considered and possible relatively small fusion cross section enhancements or suppressions are found. We show also that the barrier parameters taken from above-barrier data may be very wrong. (orig.)

  17. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  18. EAARL Coastal Topography--Northern Assateague Island National Seashore, Maryland and Virginia, 2003: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the northern half of Assateague Island National Seashore was produced from remotely sensed,...

  19. Short Rotation Woody Crops Program. Quarterly progress report, March 1-May 31, 1985. [Sycamore, alders, black locust, larch, poplars, saltbush

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L.L.; Perlack, R.D.; Wenzel, C.R.; Trimble, J.L.; Ranney, J.W.

    1985-08-01

    This report covers the progress of the Short Rotation Woody Crops Program (SRWCP) during the third quarter of fiscal year 1985. This report summarizes ORNL management activities, technical activities at ORNL and subcontract institutions, and the technology transfer that is occurring as a result of subcontractor and ORNL activities. Third-year results of a nutrient utilization study confirmed that there were no benefits to quarterly fertilization with urea nitrogen. Testing of one prototype short-rotation intensive culture harvester was conducted on a sycamore plantation on Scott Paper Company land in southern Alabama. Coppice yields of European black alder reported by Iowa State University indicate potential productivity of about 7.2 dry Mg . ha/sup -1/ . year/sup -1/ if the best trees are selected. Coppice yields were more than double first-rotation yields. About 31,000 black locust and larch trees were established in 12 genetic tests at 4 sites in Michigan. Seedling rotation productivity rates of 4-year-old hybrid poplar, based on harvest data, were reported by Pennsylvania State University. Rates varied from 4.8 dry Mg . ha/sup -1/ . year/sup -1/ to 10.7 dry Mg . ha/sup -1/ . year/sup -1/, depending on site, management strategy, and planting year. An efficient method for in vitro micropropagation of elite genotypes of fourwing saltbush was developed by Plant Resources Institute. A new study to evaluate yield/density relationships was established by the USDA Forest Service, Pacific Northwest Forest and Range Experiment Station. Dissertation research on the crown geometry of plantation-grown American sycamore was completed.

  20. Productivitatea clonelor de plop hibrid instalate în culturi intensive în nord-estul României [ Poplar clones productivity managed for biomass production in North-Eastern Romania

    Directory of Open Access Journals (Sweden)

    Dănilă I.C.

    2016-08-01

    Full Text Available Poplar (Populus spp. is a fast-growing species in temperate conditions, with potential to substitute fossil fuels by obtaining energy from biomass. The aim of this work was to study the productivity of 6 hybrid poplar clone from a hilly region of NE Romania, after a growing season of 4 and, respectively, 5 years. Rods were used as planting material, planted at a density of 2667 trees per ha, with between-row spacing of 3 m and interior-row distances of 1.25 m. Generally, significant differences appear between clones, for all analysed biometric characteristics (p≤0.05. Results show that, in the fifth growing season, diameter increases on average with 15.1%, reaching 11.89 cm, height increases in average with 13.9%, reaching 11.89 m, and volume increases with 33.3%, reaching 0.172 m3. The total biomass after 4 years vegetation varies from 32.8 t/ha to 39.4 t/ha, and after 5 years from 47.7 t/ha to 60.2 t/ha, having an average increase in the latest growing season of 35% and an average yield of 11.3 t/ha/year. The most productive clones in the given growing conditions and crop characteristics are the clone Pannonia after 4 growing seasons and the clone AF6 after 5 years.

  1. Biolimus-eluting stents with biodegradable polymer versus bare-metal stents in acute myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Kelbæk, Henning; Taniwaki, Masanori

    2014-01-01

    BACKGROUND: This study sought to determine whether the 1-year differences in major adverse cardiac event between a stent eluting biolimus from a biodegradable polymer and bare-metal stents (BMSs) in the COMFORTABLE trial (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Meta...... to improve cardiovascular events compared with BMS beyond 1 year. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NTC00962416....

  2. Phytotoxicity of fresh and weathered diesel and gasoline to willow and poplar trees

    DEFF Research Database (Denmark)

    Trapp, Stefan; Köhler, A.; Larsen, L.C.

    2001-01-01

    The toxicity of fresh and weathered gasoline and diesel fuel to willow and poplar trees was studied using a tree transpiration toxicity test. Soils were taken from an abandoned filling station. Concentrations in the samples were measured as the sum of hydrocarbons from C5 to C10 (gasoline) and C12...... to C28 (diesel). Concentrations ranged from 145 to 921 mg/kg gasoline and 143 to 18231 mg/kg diesel. The correlation between log soil concentration and toxicity to willows (Salix viminalis x schwerinii) was highly significant for the diesel fraction (r2=0.81, n=19) and for the sum of hydrocarbons (r2...... diesel and gasoline contaminated soils, and two willow and one poplar species (S. viminalis, S. alba and Populus nigra). Fresh diesel at about 1000 mg/kg showed no effect on S. alba, although P. nigra was more sensitive. 10000 mg/kg seriously affected the transpiration of all species, silver willow (S...

  3. Cometabolic degradation of trichloroethylene by Burkholderia cepacia G4 with poplar leaf homogenate.

    Science.gov (United States)

    Kang, Jun Won; Doty, Sharon Lafferty

    2014-07-01

    Trichloroethylene (TCE), a chlorinated organic solvent, is one of the most common and widespread groundwater contaminants worldwide. Among the group of TCE-degrading aerobic bacteria, Burkholderia cepacia G4 is the best-known representative. This strain requires the addition of specific substrates, including toluene, phenol, and benzene, to induce the enzymes to degrade TCE. However, the substrates are toxic and introducing them into the soil can result in secondary contamination. In this study, poplar leaf homogenate containing natural phenolic compounds was tested for the ability to induce the growth of and TCE degradation by B. cepacia G4. The results showed that the G4 strain could grow and degrade TCE well with the addition of phytochemicals. The poplar leaf homogenate also functioned as an inducer of the toluene-ortho-monooxygenase (TOM) gene in B. cepacia G4.

  4. Tree water use and rainfall partitioning in a mature poplar-pasture system.

    Science.gov (United States)

    Guevara-Escobar, A.; Edwards, W. R. N.; Morton, R. H.; Kemp, P. D.; Mackay, A. D.

    2000-01-01

    Traditionally, poplars (Populus) have been planted to control erosion on New Zealand's hill-slopes, because of their capacity to dry out and bind together the soil, by reducing effective rainfall and increasing evapotranspiration and soil strength. However, the effect of widely spaced poplars on the partitioning of soil water and rainfall has not been reported. This study determined rainfall partitioning for 18 mid-spring days in a mature P. deltoides (Bart. ex Marsh, Clone I78)-pasture association (37 stems per hectare, unevenly spaced at 16.4 +/- 0.4 m) and compared it with a traditional open pasture system in grazed areas of a hill environment. Tree transpiration was measured by the heat pulse technique. A time-driven mathematical model was used to set a zero offset, adjust anomalous values and describe simultaneous sap velocity time courses of trees. The model showed that daylight sap flow velocities can be represented with a nonlinear Beta function (R(2) > 0.98), and differences in the parameters representing the initiation, duration and conformation of the sap velocity can be tested statistically to discern tree transpiration differences during the day. Evapotranspiration was greater for the poplar-pasture association than for the open pasture (2.7-3.0 versus 2.2 mm day(-1)). The tree canopy alone contributed 0.92 mm day(-1) as transpiration and 1.37 mm day(-1) as interception, whereas evapotranspiration of the pasture understory was only 0.4-0.6 mm day(-1). Despite the higher water use of the poplar-pasture association, soil water in the 0-300 mm soil stratum was higher than, or similar to, that of the open pasture. Tree shading decreased evapotranspiration and pasture accumulation under the trees.

  5. Variation in Genomic Methylation in Natural Populations of Chinese White Poplar

    OpenAIRE

    Kaifeng Ma; Yuepeng Song; Xiaohui Yang; Zhiyi Zhang; Deqiang Zhang

    2013-01-01

    BACKGROUND: It is thought that methylcytosine can be inherited through meiosis and mitosis, and that epigenetic variation may be under genetic control or correlation may be caused by neutral drift. However, DNA methylation also varies with tissue, developmental stage, and environmental factors. Eliminating these factors, we analyzed the levels and patterns, diversity and structure of genomic methylcytosine in the xylem of nine natural populations of Chinese white poplar. PRINCIPAL FINDINGS: O...

  6. Environmental profile of ethanol from poplar biomass as transport fuel in Southern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, Sara; Moreira, M. Teresa; Feijoo, Gumersindo [Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Gasol, Carles M. [SosteniPrA (UAB-IRTA), Institute of Environmental Science and Technology (ICTA), Autonomous University of Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Gabarrell, Xavier; Rieradevall, Joan [SosteniPrA (UAB-IRTA), Institute of Environmental Science and Technology (ICTA), Autonomous University of Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Chemical Engineering Department, Autonomous University of Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain)

    2010-05-15

    Liquid biofuels provide one of the few options for fossil fuel substitution in the short to medium-term and they are strongly being promoted by the European Union as transport fuel (such as ethanol) since they have the potential to offer both greenhouse gas (GHG) savings and energy security. A ''well to wheel'' analysis has been conducted for poplar based ethanol by means of the Life Cycle Assessment (LCA) approach. The aim of the analysis is to assess the environmental performance of three ethanol applications (E10, E85 and E100) in comparison with conventional gasoline. To compare the environmental profiles, the study addressed the impact potentials per kilometre driven by a middle size passenger car, taking into account the performance difference between ethanol blends and gasoline. According to the results of this study, fuel ethanol derived from poplar biomass may help to reduce the contributions to global warming, abiotic resources depletion and ozone layer depletion up to 62%, 72% and 36% respectively. Reductions of fossil fuel extraction of up to 80% could be achieved when pure ethanol is used. On the contrary, contributions to other impact categories would be increased, specifically to acidification and eutrophication. In both categories, ethanol based blends are less environmentally friendly than conventional gasoline due to the higher impact from the upstream activities. Research focussed on the reduction of the environmental impacts should be pointed forward poplar cultivation as well as ethanol conversion plant (enzyme manufacturing, energy production and distillation). In this study poplar cultivation was really intensive in order to obtain a high yield. Strategic planning according to the location of the crops and its requirements should help to reduce these impacts from its cultivation. (author)

  7. Interaction of nitrogen nutrition and salinity in Grey poplar (Populus tremula x alba).

    Science.gov (United States)

    Ehlting, B; Dluzniewska, P; Dietrich, H; Selle, A; Teuber, M; Hänsch, R; Nehls, U; Polle, A; Schnitzler, J-P; Rennenberg, H; Gessler, A

    2007-07-01

    Salinity represents an increasing environmental problem in managed ecosystems. Populus spp. is widely used for wood production by short-rotation forestry in fertilized plantations and can be grown on saline soil. Because N fertilization plays an important role in salt tolerance, we analysed Grey poplar (Populus tremula x alba, syn. Populus canescens) grown with either 1 mM nitrate or ammonium subjected to moderate 75 mM NaCl. The impact of N nutrition on amelioration of salt tolerance was analysed on different levels of N metabolism such as N uptake, assimilation and N (total N, proteins and amino compounds) accumulation. Na concentration increased in all tissues over time of salt exposure. The N nutrition-dependent effects of salt exposure were more intensive in roots than in leaves. Application of salt reduced root increment as well as stem height increase and, at the same time, increased the concentration of total amino compounds more intensively in roots of ammonium-fed plants. In leaves, salt treatment increased concentrations of total N more intensively in nitrate-fed plants and concentrations of amino compounds independently of N nutrition. The major changes in N metabolism of Grey poplar exposed to moderate salt concentrations were detected in the significant increase of amino acid concentrations. The present results indicate that N metabolism of Grey poplar exposed to salt performed better when the plants were fed with nitrate instead of ammonium as sole N source. Therefore, nitrate fertilization of poplar plantations grown on saline soil should be preferred.

  8. RNA-SEQ reveals transcriptional level changes of poplar roots in different forms of nitrogen treatments

    Directory of Open Access Journals (Sweden)

    Chunpu eQu

    2016-02-01

    Full Text Available Poplar has emerged as a model plant for understanding molecular mechanisms of tree growth, development and response to environment. Long-term application of different forms of nitrogen (such as NO3--N and NH4+-N may cause morphological changes of poplar roots; however, the molecular level changes are still not well known. In this study, we analyzed the expression profiling of poplar roots treated by three forms of nitrogen: S1 (NH4+, S2 (NH4NO3 and S3 (NO3- by using RNA-SEQ technique. We found 463 genes significantly differentially expressed in roots by different N treatments, of which a total of 116 genes were found to differentially express between S1 and S2, 173 genes between S2 and S3, and 327 genes between S1 and S3. A cluster analysis shows significant difference in many transcription factor families and functional genes family under different N forms. Through an analysis of Mapman metabolic pathway, we found that the significantly differentially expressed genes are associated with fermentation, glycolysis and tricarboxylic acid cycle (TCA, secondary metabolism, hormone metabolism, and transport processing. Interestingly, we did not find significantly differentially expressed genes in N metabolism pathway, mitochondrial electron transport / ATP synthesis and mineral nutrition. We also found abundant candidate genes (20 transcription factors and 30 functional genes regulating morphology changes of poplar roots under the three N forms. The results obtained are beneficial to a better understanding of the potential molecular and cellular mechanisms regulating root morphology changes under different N treatments.

  9. Impact of Alkali Pretreatment on the Chemical Component Distribution and Ultrastructure of Poplar Cell Walls

    OpenAIRE

    Zhe Ji; Zhe Ling; Xun Zhang; Gui-Hua Yang; Feng Xu

    2014-01-01

    Alkali pretreatment is one of the leading pretreatment technologies for biofuel applications. The histochemical and structural characteristics of poplar cell walls were investigated before and after sodium hydroxide pretreatment (121 oC, 2%) to understand the alterations in biomass cellular structure, which were correlated with saccharification yield. Results showed that alkali pretreatment preferentially removed lignin from the S2 of fibers, which was similar to the behaviors of coniferyl al...

  10. The clonal root system of balsam poplar in upland sites of Quebec and Alberta.

    Science.gov (United States)

    Adonsou, Kokouvi E; DesRochers, Annie; Tremblay, Francine; Thomas, Barb R; Isabel, Nathalie

    2016-10-01

    Balsam poplar seeds are short-lived and require moist seedbeds soon after they are released to germinate. In addition to sexual reproduction, balsam poplar stands can regenerate clonally by root suckering. The origin of stands will in turn affect their genetic structure and root system architecture, which are poorly understood for upland forest stands. Three stands were hydraulically excavated in Quebec (moist) and Alberta (dry) to determine the origin of trees and to characterize root systems with respect to presence of parental roots and root grafts connections. Clones were identified using single-nucleotide polymorphism (SNPs), and all stems, roots and root grafts were aged using dendrochronology techniques. All 82 excavated trees were of sucker origin, and four of the six stands contained a single clone. Parental root connections were found between 22% and 25% of excavated trees, and 53% and 48% of trees were linked with a root graft between the same or different clones, in Alberta and Quebec, respectively. Mean distance between trees connected by parental root was significantly lower than the distance between unconnected trees (0.47 ± 0.25 m vs. 3.14 ± 0.15 m and 1.55 ± 0.27 m vs. 4.25 ± 0.13 m) in Alberta and in Quebec, respectively. The excavations also revealed many dead stumps with live roots, maintained through root connections with live trees. This research highlights that balsam poplar growing in upland stands is a clonal species that can maintain relatively high genotypic diversity, with frequent root connections between trees at maturity. Maintaining an extensive root system through root connections increases the chances of a clone surviving when the above ground tree is dead and may also enhance the resilience of balsam poplar stands after disturbance.

  11. Sexual dimorphism floral microRNA profiling and target gene expression in andromonoecious poplar (Populus tomentosa.

    Directory of Open Access Journals (Sweden)

    Yuepeng Song

    Full Text Available Although the molecular basis of poplar sex-specific flower development remains largely unknown, increasing evidence indicates an essential role for microRNAs (miRNAs. The specific miRNA types and precise miRNA expression patterns in dioecious plant flower development remain unclear. Here, we used andromonoecious poplar, an exceptional model system, to eliminate the confounding effects of genetic background of dioecious plants. This system, combined with high-throughput sequencing and computational analysis, allowed us to characterize sex-specific miRNAomes from female and male flowers. Comparative miRNAome analysis combined with quantitative real-time PCR revealed the expression patterns of 27 miRNAs in poplar flower and showed that the targets of these miRNAs are involved in flower organogenesis, Ca(2+ transport, phytohormone synthesis and metabolism, and DNA methylation. This paper describes a complex regulatory network consisting of these miRNAs expressed in sex-specific flower development in a dioecious plant. The conserved and novel miRNA locations were annotated in the Populus trichocarpa genome. Among these, miRNA Pto-F70 and 4 targets are located in the sex-determination regions of chromosome XIX. Furthermore, two novel miRNAs, Pto-F47 and Pto-F68, were shown for the first time to be regulatory factors in phytohormone interactions. To our knowledge, this report is the first systematic investigation of sex-specific flower-related miRNAs and their targets in poplar, and it deepens our understanding of the important regulatory functions of miRNAs in female and male flower development in this dioecious plant.

  12. Oxidative lime pretreatment of high-lignin biomass: poplar wood and newspaper.

    Science.gov (United States)

    Chang, V S; Nagwani, M; Kim, C H; Holtzapple, M T

    2001-04-01

    Lime (Ca[OH]2) and oxygen (O2) were used to enhance the enzymatic digestibility of two kinds of high-lignin biomass: poplar wood and newspaper. The recommended pretreatment conditions for poplar wood are 150 degrees C, 6 h, 0.1 g of Ca(OH)2/g of dry biomass, 9 mL of water/g of dry biomass, 14.0 bar absolute oxygen, and a particle size of -10 mesh. Under these conditions, the 3-d reducing sugar yield of poplar wood using a cellulase loading of 5 filter paper units (FPU)/g of raw dry biomass increased from 62 to 565 mg of eq. glucose/g of raw dry biomass, and the 3-d total sugar (glucose + xylose) conversion increased from 6 to 77% of raw total sugars. At high cellulase loadings (e.g., 75 FPU/g of raw dry biomass), the 3-d total sugar conversion reached 97%. In a trial run with newspaper, using conditions of 140 degrees C, 3 h, 0.3 g of Ca(OH)2/g of dry biomass, 16 mL of water/g of dry biomass, and 7.1 bar absolute oxygen, the 3-d reducing sugar yield using a cellulase loading of 5 FPU/g of raw dry biomass increased from 240 to 565 mg of eq. glucose/g of raw dry biomass. A material balance study on poplar wood shows that oxidative lime pretreatment solubilized 38% of total biomass, including 78% of lignin and 49% of xylan; no glucan was removed. Ash increased because calcium was incorporated into biomass during the pretreatment. After oxidative lime pretreatment, about 21% of added lime could be recovered by CO2 carbonation.

  13. Functional Divergence of Poplar Histidine-Aspartate Kinase HK1 Paralogs in Response to Osmotic Stress

    Directory of Open Access Journals (Sweden)

    François Héricourt

    2016-12-01

    Full Text Available Previous works have shown the existence of protein partnerships belonging to a MultiStep Phosphorelay (MSP in Populus putatively involved in osmosensing. This study is focused on the identification of a histidine-aspartate kinase, HK1b, paralog of HK1a. The characterization of HK1b showed its ability to homo- and hetero-dimerize and to interact with a few Histidine-containing Phosphotransfer (HPt proteins, suggesting a preferential partnership in poplar MSP linked to drought perception. Furthermore, determinants for interaction specificity between HK1a/1b and HPts were studied by mutagenesis analysis, identifying amino acids involved in this specificity. The HK1b expression analysis in different poplar organs revealed its co-expression with three HPts, reinforcing the hypothesis of partnership participation in the MSP in planta. Moreover, HK1b was shown to act as an osmosensor with kinase activity in a functional complementation assay of an osmosensor deficient yeast strain. These results revealed that HK1b showed a different behaviour for canonical phosphorylation of histidine and aspartate residues. These phosphorylation modularities of canonical amino acids could explain the improved osmosensor performances observed in yeast. As conserved duplicates reflect the selective pressures imposed by the environmental requirements on the species, our results emphasize the importance of HK1 gene duplication in poplar adaptation to drought stress.

  14. Effects of Cutting Density on Growth,Yield and Quality of Poplar Clone Seedlings

    Institute of Scientific and Technical Information of China (English)

    Fang Shengzuo; Tian Ye; Yuan Fayin

    2006-01-01

    In order to identify the optimum cutting density for producing the highest number of plantable seedlings of poplar clones,a split-plot randomized block design was used to establish four cutting densities in plots.Based on data on the survival,leaf area,seedling height,caliper,and biomass of 1-year-old seedlings of clones Nanlin-95,Nanlin-895,Nanlin-1388 and NL-80351,the growth characteristics and seedling quality under four cutting densities were analyzed.Results indicated that the leaf area,stern and leaf biomass,and caliper of seedlings of all four poplar clones increased with the decrease in cutting density.Leaf area index reached its highest level at the spacing of 40 cm×40 cm,while the aboveground biomass of the seedling on an area basis increased as the cutting density increased.Seedling quality at low cutting density was higher than that at closer cutting density.The quantity of first-grade seedlings (grade Ⅰ) for clones Nanlin-95 and Nanlin-895 was achieved at the spacing of 40 cm×50 cm;for NL-1388 and NL-80351,it was 50 cm×50 cm.According to the seedling quality and the number of plantable seedlings produced,the suggested cutting density for these four poplar clones was 50,000 stems/hm2.

  15. An In-Depth Understanding of Biomass Recalcitrance Using Natural Poplar Variants as the Feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xianzhi [Department of Chemical & Biomolecular Engineering, University of Tennessee Knoxville, Knoxville TN 37996 USA; Pu, Yunqiao [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Yoo, Chang Geun [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Li, Mi [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Bali, Garima [Renewable Bioproducts Institute, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta GA 30332 USA; Park, Doh-Yeon [Renewable Bioproducts Institute, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta GA 30332 USA; Gjersing, Erica [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; National Renewable Energy Laboratory, Golden CO 80401 USA; Davis, Mark F. [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; National Renewable Energy Laboratory, Golden CO 80401 USA; Muchero, Wellington [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Tuskan, Gerald A. [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Tschaplinski, Timothy J. [BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Ragauskas, Arthur J. [Department of Chemical & Biomolecular Engineering, University of Tennessee Knoxville, Knoxville TN 37996 USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Center for Renewable Carbon, Department of Forestry, Wildlife, and Fisheries, University Tennessee Institute of Agriculture, Knoxville TN 37996 USA

    2016-12-12

    In an effort to better understand the biomass recalcitrance, six natural poplar variants were selected as feedstocks based on previous sugar release analysis. Compositional analysis and physicochemical characterizations of these poplars were performed and the correlations between these physicochemical properties and enzymatic hydrolysis yield were investigated. Gel permeation chromatography (GPC) and 13C solid state NMR were used to determine the degree of polymerization (DP) and crystallinity index (CrI) of cellulose, and the results along with the sugar release study indicated that cellulose DP likely played a more important role in enzymatic hydrolysis. Simons' stain revealed that the accessible surface area of substrate significantly varied among these variants from 17.3 to 33.2 mg g-1/biomass as reflected by dye adsorption, and cellulose accessibility was shown as one of the major factors governing substrates digestibility. HSQC and 31P NMR analysis detailed the structural features of poplar lignin variants. Overall, cellulose relevant factors appeared to have a stronger correlation with glucose release, if any, than lignin structural features. Lignin structural features, such as a phenolic hydroxyl group and the ratio of syringyl and guaiacyl (S/G), were found to have a more convincing impact on xylose release. Low lignin content, low cellulose DP, and high cellulose accessibility generally favor enzymatic hydrolysis; however, recalcitrance cannot be simply judged on any single substrate factor.

  16. Leaf energy balance and transpirational relationships of tulip poplar (Liriodendron tulipifera)

    Energy Technology Data Exchange (ETDEWEB)

    McConathy, R.K.; McLaughlin, S.B.; Reichle, D.E.; Dinger, B.E.

    1976-10-01

    Relationships between several physiological parameters of in situ tulip poplar (Liriodendron tulipifera L.) foliage, and its surrounding forest environment were examined, with emphasis on the transpirational process. Objectives were to measure and compare stomatal relationships with environmental and plant morphological variables, determine and assess the relative importance of factors affecting transpiration and leaf energy balance of a mature tulip poplar, examine and describe the diurnal kinetics of transpiration and leaf energy balance under forest conditions, and examine and develop equations describing these processes and relationships. Tulip poplar leaves were examined at three crown heights. Stomatal distribution, density, and dimensions were measured, then these data were used to predict leaf diffusion layer resistance. Stomatal dimensions decreased with crowned height while stomatal density increased, but neither varied over individual leaf surfaces. Numbers of stomata per leaf were constant throughout the crown. Calculated transpiration rates were compared with stomatal diffusion resistance, leaf xylem water potential, and environmental parameters. Diurnal leaf heat loss, water stress, and stomatal resistance measurements followed the diurnal variation of the radiation absorbed by the leaf. Heat loss by radiation, evaporation, and convection varied with crown height in response to variations in stomatal diffusion resistance, transpiration, vapor pressure deficit, leaf temperature, and wind speed.

  17. Molecular evaluations of thirty one clones of poplar based on RAPD and SSR molecular markers

    Directory of Open Access Journals (Sweden)

    Singh M.K.

    2014-01-01

    Full Text Available Poplar is an important tree species valued all over the world for its wood importance. Despite limited knowledge of the levels of genetic diversity and relatedness, their cultivation as a source of plywood is widespread. In order to facilitate reasoned scientific decisions on its management and conservation and prepare for selective breeding programme, genetic analysis of 31 genotypes was performed using RAPD and SSR molecular markers. Twenty six RAPD primers and 14 SSR primers amplified a total of 236 and 85 scoreable bands of which 86.44% and 86.02% were polymorphic. The mean coefficient of gene differentiation (Gst was 0.388 and 0.341 indicating that 61.2% and 65.9% of the genetic variation resided within the populations. Analysis of molecular variance (AMOVA indicated that majority of genetic variation (94.6% using RAPD and 89% using SSR occurred among genotypes, while the variation between the three groups (categorized as tall, medium and small plants height was 5.4% (using RAPD and 11% (using SSR. The dendrogram obtained from NJ and STRUCTURE analysis revealed splitting of genotypes into four clusters with clear distinction between short, medium and tall height genotypes, indicated that genetic differentiations measure with respect to RAPD and SSR. However, both the markers were equally useful in providing some understanding about the genetic relationship of different genotypes of poplar that are important in the conservation and exploitation of poplar genetic resources.

  18. Investigation of horizontal gene transfer in poplar/Amanita muscaria ectomycorrhizas.

    Science.gov (United States)

    Zhang, Chi; Hampp, Rüdiger; Nehls, Uwe

    2005-01-01

    Fine roots of forest trees form together with certain soil fungi symbiotic structures (ectomycorrhizas), where fungal hyphae are in intimate contact with plant cells. Due to root cell degeneration, plant DNA is released and could be taken up by the fungus. The possibility that horizontal gene transfer might result in a risk for the environment should be evaluated before a massive release of genetically engineered trees into nature occurs, even though only a few convincing examples of horizontal gene transfer are known. Transgenic poplars containing a construct of the Streptomyces hygroscopicus bar gene under the control of the Cochliobolus heterostrophus GPD (glyceraldehyde-3-phosphate dehydrogenase) promoter were generated by Agrobacterium-mediated transformation. The functionality of this construct in the ectomycorrhizal model fungus Amanita muscaria was previously verified by protoplast-based fungal transformation. 35,000 ectomycorrhizas, formed between transgenic poplars and non-transgenic A. muscaria hyphae, were isolated and transferred to selective agar plates. Putative herbicide-resistant fungal colonies were obtained after the first round of selection. However, none of these colonies survived a transfer onto fresh selection medium, nor did they contain the bar gene, indicating that no horizontal gene transfer from poplar to A. muscaria occurred during symbiosis under axenic conditions. However, since ectomycorrhizas are associated under natural conditions with viruses, bacteria and other fungi, these additional associations should be evaluated in future.

  19. Dense poplar plantations as the raw material for the production of energy

    Directory of Open Access Journals (Sweden)

    Klašnja Bojana

    2006-01-01

    Full Text Available The higher heating value of wood and bark was determined for several poplar (Populus spp clones. The study included the juvenile one year old plants of the following clones: P.×euramericana cl. ostia, P. nigra cl.53/86, P. deltoides cl. PE 19/66, P.×euramericana cl. I-214, P. deltoides cl. S6-7 and P.×euramericana cv. robusta. By using FVI which takes into account ash content, wood bulk density, and moisture content, it was determined that poplar wood can be a significant energy raw material, primarily thanks to its short rotation cycle and a very high wood volume increment. Significant differences were determined in the values of wood basic density which affect the higher heating value of the study poplar clones, and consequently the yield (weight of biomass produced per unit area of dense plantations. This is reflected also on the estimated amount of energy that can be produced by the combustion of biomass of the whole one year old plants.

  20. Yield and spatial supply of bioenergy poplar and willow short-rotation coppice in the UK.

    Science.gov (United States)

    Aylott, Matthew J; Casella, E; Tubby, I; Street, N R; Smith, P; Taylor, Gail

    2008-01-01

    Limited information on likely supply and spatial yield of bioenergy crops exists for the UK. Here, productivities are reported of poplar (Populus spp.) and willow (Salix spp.) grown as short-rotation coppice (SRC), using data from a large 49-site yield trial network. A partial least-squares regression technique was used to upscale actual field trial observations across England and Wales. Spatial productivity was then assessed under different land-use scenarios. Mean modelled yields ranged between 4.9 and 10.7 oven-dry tonnes (odt) ha(-1) yr(-1). Yields were generally higher in willow than in poplar, reflecting the susceptibility of older poplar genotypes to rust and their tendency for single stem dominance. Replacing 10% of arable land, 20% of improved grassland and 100% of set-aside grassland in England and Wales with the three most productive genotypes would yield 13 Modt of biomass annually (supplying 7% of UK electricity production or 48% of UK combined heat and power (CHP) production). Results show existing SRC genotypes have the immediate potential to be an important component of a mixed portfolio of renewables and that, in future, as new and improved genotypes become available, higher yields could extend this potential further.

  1. Short rotation coppice culture of willows and poplars as energy crops on metal contaminated agricultural soils.

    Science.gov (United States)

    Ruttens, Ann; Boulet, Jana; Weyens, Nele; Smeets, Karen; Adriaensen, Kristin; Meers, Erik; Van Slycken, Stijn; Tack, Filip; Meiresonne, Linda; Thewys, Theo; Witters, Nele; Carleer, Robert; Dupae, Joke; Vangronsveld, Jaco

    2011-01-01

    Phytoremediation, more precisely phytoextraction, has been placed forward as an environmental friendly remediation technique, that can gradually reduce increased soil metal concentrations, in particular the bioavailable fractions. The aim of this study was to investigate the possibilities of growing willows and poplars under short rotation coppice (SRC) on an acid, poor, sandy metal contaminated soil, to combine in this way soil remediation by phytoextraction on one hand, and production of biomass for energy purposes on the other. Above ground biomass productivities were low for poplars to moderate for willows, which was not surprising, taking into account the soil conditions that are not very favorable for growth of these trees. Calculated phytoextraction efficiency was much longer for poplars than these for willows. We calculated that for phytoextraction in this particular case it would take at least 36 years to reach the legal threshold values for cadmium, but in combination with production of feedstock for bioenergy processes, this type of land use can offer an alternative income for local farmers. Based on the data of the first growing cycle, for this particular case, SRC of willows should be recommended.

  2. Overexpression of poplar cellulase accelerates growth and disturbs the closing movements of leaves in sengon.

    Science.gov (United States)

    Hartati, Sri; Sudarmonowati, Enny; Park, Yong Woo; Kaku, Tomomi; Kaida, Rumi; Baba, Kei'ichi; Hayashi, Takahisa

    2008-06-01

    In this study, poplar (Populus alba) cellulase (PaPopCel1) was overexpressed in a tropical Leguminosae tree, sengon (Paraserianthes falcataria), by the Agrobacterium tumefaciens method. PaPopCel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. The pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. When main veins from each genotype were excised and placed on a paper towel, however, the leaves of the transgenic plants closed more rapidly than those of the wild-type plant. Based on carbohydrate analyses of cell walls, the leaves of the transgenic plants contained less wall-bound xyloglucan than those of the wild-type plants. In situ xyloglucan endotransglucosylase activity showed that the incorporation of whole xyloglucan, potentially for wall tightening, occurred in the parenchyma cells (motor cells) of the petiolule pulvinus attached to the main vein, although the transgenic plant incorporated less whole xyloglucan than the wild-type plant. These observations support the hypothesis that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase, which loosens xyloglucan intercalation, resulting in an irreversible wall modification. This process could be the reason why the overexpression of poplar cellulase both promotes plant growth and disturbs the biological clock of the plant by altering the closing movements of the leaves of the plant.

  3. Investigating Mass Transport Limitations on Xylan Hydrolysis During Dilute Acid Pretreatment of Poplar

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh; Pilath, Heid M.; Parent, Yves; Chatterjee, Siddharth G.; Donohoe, Bryon S.; Yarbrough, John M.; Himmel, Michael E.; Nimlos, Mark R.; Johnson, David K.

    2014-04-28

    Mass transport limitations could be an impediment to achieving high sugar yields during biomass pretreatment and thus be a critical factor in the economics of biofuels production. The objective of this work was to study the mass transfer restrictions imposed by the structure of biomass on the hydrolysis of xylan during dilute acid pretreatment of biomass. Mass transfer effects were studied by pretreating poplar wood at particle sizes ranging from 10 micrometers to 10 mm. This work showed a significant reduction in the rate of xylan hydrolysis in poplar when compared to the intrinsic rate of hydrolysis for isolated xylan that is possible in the absence of mass transfer. In poplar samples we observed no significant difference in the rates of xylan hydrolysis over more than two orders of magnitude in particle size. It appears that no additional mass transport restrictions are introduced by increasing particle size from 10 micrometers to 10 mm. This work suggests that the rates of xylan hydrolysis in biomass particles are limited primarily by the diffusion of hydrolysis products out of plant cell walls. A mathematical description is presented to describe the kinetics of xylan hydrolysis that includes transport of the hydrolysis products through biomass into the bulk solution. The modeling results show that the effective diffusion coefficient of the hydrolysis products in the cell wall is several orders of magnitude smaller than typical values in other applications signifying the role of plant cell walls in offering resistance to diffusion of the hydrolysis products.

  4. Ectomycorrhizal colonization and diversity in relation to tree biomass and nutrition in a plantation of transgenic poplars with modified lignin biosynthesis.

    Science.gov (United States)

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R(2) = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  5. Extraction of two kinds of bare lands around cities and its significance to city development

    Science.gov (United States)

    Li, R.; Yue, Y. M.; Liu, Bo; Zhang, X.; Tian, X.

    2014-05-01

    In china, especially in the North and Northwest, many cities suffer sand-dust or sand-storm attacks in winter and spring. There are two sand sources forming the bad weather, local sand source and other source out of local area. The second kind source needs state level activities to control sand movement and recover local ecological environment. For the local government, it should pay much attention to decreasing its inner sand & dust source, because the sand-stormy or sand-dusty weather causing by the local sand source usually comes abruptly and brings much damage frequently, and it is also hard to forecast it. However, people always emphasize all-year bare land controlling and pay less attention to seasonal bare land (especially in winter and spring seasons) which caused by unreasonable agricultural pattern. In this paper, taking Beijing as the test area, using MODIS vegetation index time-series data, all-year and seasonal bare land had been classified. The data set used was 16-day composited EVI time-series with a 250m spatial resolution. After filtered and reconstructed, this paper applied the parallelepiped classification algorithm to the data set, and emphasized the all-year bare land with lower EVI value and seasonal bare land with lower EVI value just in spring and winter. Taking accord of local terrain, infield was the main part of seasonal bare land. The experiment result showed that all-year bare land mainly distributes in northwest Beijing, the joint area of Beijing, Shanxi and Inner Mongolia, especially in Inner Mongolia. Seasonal bare land mainly distributes in northwest and west Beijing, gathering in northwest Hebei, east Shanxi; there are also some ones in Daxing, fangshan, changpin, yanqing, miyun, shunyi, and tongzhou areas of Beijing. These two kind bare lands were all possible contributor to sand storm or sand dust weather in Beijing. Considering wind direction and terrain information of Beijing area, some possible sand source could be found

  6. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  7. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    Directory of Open Access Journals (Sweden)

    A. Kiendler-Scharr

    2012-01-01

    Full Text Available Stress-induced volatile organic compound (VOC emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m−2 s−1 in non-transgenic controls (wild type WT and nearly zero (<0.5 nmol m−2 s−1 in isoprene emission-repressed plants (line RA22, respectively. Nucleation rates of up to 3600 cm−3 s−1 were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8 was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  8. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    Directory of Open Access Journals (Sweden)

    A. Kiendler-Scharr

    2011-08-01

    Full Text Available Stress-induced volatile organic compound (VOC emissions from transgenic Grey poplar, modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA formation. Nucleation rates of up to 3600 cm−3 s−1 were observed in our experiments. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m−2 s−1 in non-transgenic controls (wild type WT and nearly zero (<0.5 nmol m−2 s−1 in isoprene emission-repressed lines (line RA22, respectively. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8 was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3 % of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  9. GHGs balance in a land use change process from grassland to short rotation coppice of poplar

    Science.gov (United States)

    Sabbatini, Simone; Arriga, Nicola; Baiocco, Andrea; Boschi, Alessio; Castaldi, Simona; Consalvo, Claudia; Gioli, Beniamino; Matteucci, Giorgio; Tomassucci, Michele; Zaldei, Alessandro; Papale, Dario

    2013-04-01

    At present one of the fastest spreading renewable energy sources are bioenergy cultivations. Millions of hectares of traditional crops all over the Europe are expected to be converted in energy crops in the near future, in order to produce green energy and contrast global warming. Last year, in the context of the GHG-Europe FP7 project we set up an experiment to verify the effects on the green-house gases balance of a land use change from traditional agriculture to short rotation coppice of poplar clones in central Italy. CO2 fluxes measured during the last growing season through three Eddy Covariance masts - two on poplar plantations of different ages and one over a reference site (grassland) - have been analysed. We also monitored CO2, CH4 and N2O fluxes from soil measured using chambers in order to better understand the contribution of other GHGs. The two poplar plantations showed a similar uptake of Carbon, 368 g C m-2 year-1 and 358 g C m-2 year-1, while the grassland absorbed 220 g C m-2 year-1 during the same period. Soil respiration in average was higher for the youngest plantation of poplar and for the grassland, lower for the oldest one, where soil is undisturbed from more time. In all the sites we measured low emissions during the winter (between 80 and 150 mg CO2 m-2 h-1), progressively higher in the spring and early summer with growing temperatures (up to 650 mg CO2 m-2 h-1), quite low during the summer because of a strong drought, while the highest values were recorded in September (ca. 1100 mg CO2 m-2 h-1 in the grassland and youngest poplar) after important rain events. Fluxes of N2O and CH4 from soil are very low: little absorption of CH4 in the grassland (values between 0 and -18.75 μg m-2 h-1), with peak after fertilization; in the SRC little absorption or emission with no clear seasonal pattern. Insignificant fluxes of N2O in all crops (even in the grassland after fertilization). The carbon fluxes measured are strongly related to the particular

  10. Conversion from cropland to short rotation coppice willow and poplar: Accumulation of soil organic carbon

    Science.gov (United States)

    Georgiadis, Petros; Stupak, Inge; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-04-01

    Increased demand for bioenergy has intensified the production of Short Rotation Coppice (SRC) willow and poplar in temperate zones. We used a combined chronosequence and paired plot approach to study the potential of SRC willow and poplar stands to increase the soil carbon stock compared to stocks of the previous arable land-use. The study focused on well-drained soils. We sampled soil from 30 SRC stands in Denmark and southern Sweden including soils from their adjacent arable fields. The 18 willow and 12 poplar stands formed a chronosequence ranging between 4 and 29 years after conversion. The soil was sampled both with soil cores taken by fixed depths of 0-5, 5-10, 10-15, 15-25, and 25-40 cm and by genetic horizons from soil pits to 1m depth. The aim of the study was to estimate the difference and the ratio between soil carbon contents of the SRC and annual crop land and analyze the results as a chronosequence to examine the effect of age after conversion on the difference. Covariates such as soil type, fertilization type and harvest frequency were also taken into account. Preliminary results suggest an overall increase in carbon stocks over time with average accumulation rates ranging from 0.25 to 0.4 Mg ha-1 yr-1 in willow and poplar stands. Poplar stands had higher rates of C gain, probably due to less frequent harvesting. The differences in carbon between the SRC and the paired cropland were initially negative but changed to positive over time, implying loss of carbon after conversion and a later gain in soil carbon with stand age. Pairwise differences ranged from -25 Mg C ha-1 to 37 Mg C ha-1 for the top 40 cm. The carbon stock ratio of the SRC stand to the arable land was estimated to minimize the effect of site-related factors. The results of this analysis suggested that the ratio increased significantly with age after conversion for the top 10 cm of the soil, both for poplar and willow. A slight increase with age was also noticed at the deeper depths, but

  11. Investigation on the Effect of Kenaf Core and Stalk Fiber on the Medium Density Fiber Board Properties Made of Poplar Fibers

    Directory of Open Access Journals (Sweden)

    Fahimeh SH.Alizadeh

    2012-01-01

    Full Text Available In order to optimize the use of material non-forest resources, in this study the possibility of using the kenaf stalk fibers mixed with poplar fibers in producing medium density fiber board was considered. Variable factors such as density at two levels (0.55, 0.75 g/cm3 and the percentage incorporation of fiber (%50 poplar fibers, - %50 kenaf core fiber, %50 poplar fiber, -% 50 kenaf stalk fiber and %100 poplar fibers were considered. Steaming time and temperature (175°C, 10min, press time and temperature (5 min, 175°C, Pressing pressure (30 kg/cm3, fiber cake moisture (%12 and urea-formaldehyde resin with Concentration of %50 of the study factors were fixed. Results show that adding kenaf core fibers to the poplar fibers increases modulus of elasticity and water absorption but thickness swelling reduces. Increased density in board made with kenaf core has caused increase in bending strength, modulus of elasticity and internal bond strength and their water absorption and thickness swelling after 2 and 24 hours were competitive with poplar (MDF. On the other hand Populus fiber– kenaf stalk board mechanical and physical properties were competitive with (MDF board made of %100 poplar fibers. Finally we can say that according to the statistical analysis, the best treatment in this study was using kenaf core fibers, in making poplar (MDF with 0.75 g/cm3 density.

  12. Coppicing shifts CO2 stimulation of poplar productivity to above-ground pools: a synthesis of leaf to stand level results from the POP/EUROFACE experiment

    NARCIS (Netherlands)

    Liberloo, M.; Lukac, M.; Calfapietra, C.; Hoosbeek, M.R.; Gielen, B.; Miglietta, F.; Mugnozza, G.S.; Ceulemans, R.

    2009-01-01

    A poplar short rotation coppice (SRC) grown for the production of bioenergy can combine carbon (C) storage with fossil fuel substitution. Here, we summarize the responses of a poplar (Populus) plantation to 6 yr of free air CO2 enrichment (POP/EUROFACE consisting of two rotation cycles). We show tha

  13. [Time lag effect between poplar' s sap flow velocity and microclimate factors in agroforestry system in West Liaoning Province].

    Science.gov (United States)

    Di, Sun; Guan, De-xin; Yuan, Feng-hui; Wang, An-zhi; Wu, Jia-bing

    2010-11-01

    By using Granier's thermal dissipation probe, the sap flow velocity of the poplars in agroforestry system in west Liaoning was continuously measured, and the microclimate factors were measured synchronously. Dislocation contrast method was applied to analyze the sap flow velocity and corresponding air temperature, air humidity, net radiation, and vapor pressure deficit to discuss the time lag effect between poplar' s sap flow velocity and microclimate factors on sunny days. It was found that the poplar's sap flow velocity advanced of air temperature, air humidity, and vapor pressure deficit, and lagged behind net radiation. The sap flow velocity in June, July, August, and September was advanced of 70, 30, 50, and 90 min to air temperature, of 80, 30, 40, and 90 min to air humidity, and of 90, 50, 70, and 120 min to vapor pressure deficit, but lagged behind 10, 10, 40, and 40 min to net radiation, respectively. The time lag time of net radiation was shorter than that of air temperature, air humidity, and vapor pressure. The regression analysis showed that in the cases the time lag effect was contained and not, the determination coefficients between comprehensive microclimate factor and poplar's sap flow velocity were 0.903 and 0.855, respectively, indicating that when the time lag effect was contained, the determination coefficient was ascended by 2.04%, and thus, the simulation accuracy of poplar's sap flow velocity was improved.

  14. Genome survey and characterization of endophytic bacteria exhibiting a beneficial effect on growth and development of poplar trees.

    Science.gov (United States)

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-02-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides x Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels.

  15. Recognition and rating of effecting indexes on consumption of different sites poplar wood production in Iran for paper making industries

    Directory of Open Access Journals (Sweden)

    ebrahim lashkarbolouki

    2016-12-01

    Full Text Available Considering the growth in population, the need for wood consumption also increases. The rapid progress of science and technology doubles the wood consumption. Supplying this need at a glance was focused on the forests. Forests for many reasons have faced decrease in production and this extreme need for wood, by planting fast growing trees (poplar, eucalypt, Paulownia … makes it possible. One of industries plenty of the wood is paper industry that needs to huge primary wood material. This industry can continue their production activities by using the wood of poplar. This research was found out with the aim of assessing the practical characteristics of poplar wood by nondestructive test method in paper production industry. Poplar sites were selected in areas of country that poplar trees were planted widely. For locating the production of different site in paper industry found out Analytic Hierarchy Process (AHP in Expert choice 11 software. For field studies of this research, the questionnaires were prepared and sent for expert and university professors with special expertise in this industry. The results showed that: Production of Pulp and paper industry: in this industry among of five main indexes influencing in pulp and paper production, fiber morphology trait recognized as first priority with weighting value (0.435. Production allocations with their weighting value are determined: Sari (0.240, Fouman (0.236, Lashtnasha (0.182, Abhar (0.174 and Zanjan (0.168, respectively.

  16. Electrochemical and Optical Evaluation of Noble Metal-and Carbon-ITO Hybrid Optically Transparent Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zudans, Imants; Paddock, Jean R.; Kuramitz, Hideki; Maghasi, Anne T.; Wansapura, Chamika M.; Conklin, Sean D.; Kaval, Necati; Shtoyko, Tanya; Monk, David J.; Bryan, Samuel A.; Hubler, Timothy L.; Richardson, John N.; Seliskar, Carl J.; Heineman, William R.

    2004-04-15

    Optically transparent hybrid electrodes were constructed by sputtering or thermally evaporating layers of varying thickness of Au, Pd, Pt, or C onto an existing conductive indium-tin oxide (ITO) layer on glass. These electrodes were characterized using UV-Vis spectroscopy and cyclic voltammetry; redox probes examined were potassium ferricyanide, tris-(2, 2'-bipyridyl)ruthenium(II) chloride, hydroquinone, and para-aminophenol (PAP). Each type of hybrid was evaluated and compared with other hybrids, as well as with bare ITO electrodes and commercially available Au, Pt, and glassy carbon disk electrodes. Our results indicated that these hybrid electrodes are reasonably robust, easy to prepare, and extend the capabilities of bare ITO surfaces with respect to the electrochemical response (especially for organic redox probes), while giving up little in the way of optical transparency. Because of these characteristics, hybrid electrodes should be especially suited to many spectroelectrochemical applications.

  17. Karst bare slope soil erosion and soil quality: a simulation case study

    Directory of Open Access Journals (Sweden)

    Q. Dai

    2015-06-01

    Full Text Available The influence on soil erosion by different bedrock bareness ratios, different rainfall intensities, different underground pore fissure degrees and rainfall duration are researched through manual simulation of microrelief characteristics of karst bare slopes and underground karst crack construction in combination with artificial simulation of rainfall experiment. The results show that firstly, when the rainfall intensity is small (30 and 50 mm h−1, no bottom load loss is produced on the surface, and surface and underground runoff and sediment production is increased with the increasing of rainfall intensity; secondly, surface runoff and sediment production reduced with increased underground pore fissure degree, while underground runoff and sediment production increased; thirdly, raindrops hit the surface, forming a crust with rainfall duration. The formation of crusts increases surface runoff erosion and reduces soil infiltration rate. Increasing of surface runoff erosion damaged crust and increased soil seepage rate. Raindrops continued to hit the surface, leading the formation of crust. Soil permeability showed volatility which were from reduction to increases and reduction, and so on. Surface and subsurface runoff were volatility with rainfall duration; fourthly, when rock bareness ratio is 50% and rainfall intensities are 30 and 50 mm h−1, runoff is not produced on the surface, and the slope runoff and sediment production presents a fluctuating change with increased rock bareness ratio; fifthly, the correlation degree between the slope runoff and sediment production and all factors are as follows: rainfall intensity > rainfall duration > underground pore fissure degree > bed rock bareness ratio.

  18. QTLs for Woolly Poplar Aphid (Phloeomyzus passerinii L. Resistance Detected in an Inter-Specific Populus deltoides x P. nigra Mapping Population.

    Directory of Open Access Journals (Sweden)

    Giorgia Carletti

    Full Text Available The genus Populus represents one of the most economically important groups of forest trees. It is composed by approximately 30 species used for wood and non-wood products, phytoremediation and biomass. Poplar is subjected to several biological and environmental threats although, compared to annual crops, we know far less about the genetic bases of biotic stress resistance. Woolly poplar aphid (Phloeomyzus passerinii is considered a main pest of cultivated poplars in European and American countries. In this work we present two high density linkage maps in poplar obtained by a genotyping by sequencing (GBS approach and the identification of QTLs involved in Ph. passerinii resistance. A total of 5,667 polymorphic markers (5,606 SNPs and 61 SSRs identified on expressed sequences have been used to genotype 131 plants of an F1 population P ×canadensis obtained by an interspecific mate between Populus deltoides (resistant to woolly poplar aphid and Populus nigra (susceptible to woolly poplar aphid. The two linkage maps, obtained following the two-way pseudo-testcross mapping strategy, have been used to investigate the genetic bases of woolly poplar aphid resistance. One major QTL and two QTLs with minor effects (mapped on LGV, LGXVI and LG XIX explaining the 65.8% of the genetic variance observed in the progeny in response to Ph. passerinii attack were found. The high density coverage of functional markers allowed the identification of three genes belonging to disease resistance pathway as putative candidates for P. deltoides resistance to woolly poplar aphid. This work is the first report on genetic of woolly poplar aphid genetic resistance and the resistant loci associated markers identified represent a valuable tool in resistance poplar breeding programs.

  19. The Comparison of Bare Sclera and Rotational Flap Methods in Primary Pterygium Surgery

    Directory of Open Access Journals (Sweden)

    N. Bazazi

    2005-01-01

    Full Text Available The objective of this study was the comparison of Bare Sclera and Rotational Flap methods in primary pterygium surgery. This study was retrospective Cohort and studied population were 80 patients (40 patients in each group with primary pterygium in stage II and III operated in Hamadan Emam Khomeini hospital , during 2001-2003. All of the patients followed up 48 hours , 1 week , 1,3 and 6 months after operative surgery. In this study , complications and recurrences of both methods (Bare Sclera and Rotational Flap were compared and the results were as follows : Recurrence rate in Bare Sclera method was 22.5% and in rotational flap method 11.1% , that obtained no significant relationship between two groups. Also there was not significant difference in complications.

  20. Patches of bare ground as a staple commodity for declining ground-foraging insectivorous farmland birds.

    Science.gov (United States)

    Schaub, Michael; Martinez, Nicolas; Tagmann-Ioset, Aline; Weisshaupt, Nadja; Maurer, Melanie L; Reichlin, Thomas S; Abadi, Fitsum; Zbinden, Niklaus; Jenni, Lukas; Arlettaz, Raphaël

    2010-10-06

    Conceived to combat widescale biodiversity erosion in farmland, agri-environment schemes have largely failed to deliver their promises despite massive financial support. While several common species have shown to react positively to existing measures, rare species have continued to decline in most European countries. Of particular concern is the status of insectivorous farmland birds that forage on the ground. We modelled the foraging habitat preferences of four declining insectivorous bird species (hoopoe, wryneck, woodlark, common redstart) inhabiting fruit tree plantations, orchards and vineyards. All species preferred foraging in habitat mosaics consisting of patches of grass and bare ground, with an optimal, species-specific bare ground coverage of 30-70% at the foraging patch scale. In the study areas, birds thrived in intensively cultivated farmland where such ground vegetation mosaics existed. Not promoted by conventional agri-environment schemes until now, patches of bare ground should be implemented throughout grassland in order to prevent further decline of insectivorous farmland birds.

  1. Enhanced enzymatic hydrolysis of poplar bark by combined use of gamma ray and dilute acid for bioethanol production

    Science.gov (United States)

    Chung, Byung Yeoup; Lee, Jae Taek; Bai, Hyoung-Woo; Kim, Ung-Jin; Bae, Hyeun-Jong; Gon Wi, Seung; Cho, Jae-Young

    2012-08-01

    Pretreatment of poplar bark with a combination of sulfuric acid (3%, w/w, H2SO4) and gamma irradiation (0-1000 kGy) was performed in an attempt to enhance enzymatic hydrolysis for bioethanol production. The yields of reducing sugar were slightly increased with an increasing irradiation dose, ranging from 35.4% to 51.5%, with a 56.1% reducing sugar yield observed after dilute acid pretreatment. These results clearly showed that soluble sugars were released faster and to a greater extent in dilute acid-pretreated poplar bark than in gamma irradiation-pretreated bark. When combined pretreatment was carried out, a drastic increase in reducing sugar yield (83.1%) was found compared with individual pretreatment, indicating the possibility of increasing the convertibility of poplar bark following combined pretreatment. These findings are likely associated with cellulose crystallinity, lignin modification, and removal of hemicelluloses.

  2. Wastewater and sewage sludge application to willows and poplars grown in lysimeters-Plant response and treatment efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, I.; Aronsson, P. [Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), Ecology building, P.O. Box 7043, SE 750 07 Uppsala (Sweden)

    2011-01-15

    Adding nutrient-rich residues such as municipal wastewater and sludge to willow and poplar short-rotation coppice gives more cost-effective and sustainable cultivation, but leaching to groundwater and disturbance to plant growth must be avoided. The effects of adding municipal wastewater irrigation to willows and poplars and sewage sludge to willows were compared in a two-year experiment. Wastewater irrigation enhanced plant growth. Near-zero nitrate-N concentrations occurred in drainage water when the root system of both species was well-established. The ability to retain N and P was satisfactory when poplars and willows were irrigated with wastewater. Thus relatively high additions of N and P with wastewater will probably not contaminate groundwater, but potential P leaching should not be underestimated. The same applies for sewage sludge applications to willow. (author)

  3. A Field Trial of TCE Phytoremediation by Genetically Modified Poplars Expressing Cytochrome P450 2E1.

    Science.gov (United States)

    Legault, Emily K; James, C Andrew; Stewart, Keith; Muiznieks, Indulis; Doty, Sharon L; Strand, Stuart E

    2017-06-06

    A controlled field study was performed to evaluate the effectiveness of transgenic poplars for phytoremediation. Three hydraulically contained test beds were planted with 12 transgenic poplars, 12 wild type (WT) poplars, or left unplanted, and dosed with equivalent concentrations of trichloroethylene (TCE). Removal of TCE was enhanced in the transgenic tree bed, but not to the extent of the enhanced removal observed in laboratory studies. Total chlorinated ethene removal was 87% in the CYP2E1 bed, 85% in the WT bed, and 34% in the unplanted bed in 2012. Evapotranspiration of TCE from transgenic leaves was reduced by 80% and diffusion of TCE from transgenic stems was reduced by 90% compared to WT. Cis-dichloroethene and vinyl chloride levels were reduced in the transgenic tree bed. Chloride ion accumulated in the planted beds corresponding to the TCE loss, suggesting that contaminant dehalogenation was the primary loss fate.

  4. Estimating Vegetation Height and Bare-Earth Topography from SRTM Data using Fourier Spectral Decomposition

    Science.gov (United States)

    Gangodagamage, C.; Liu, D.; Alsdorf, D.

    2010-12-01

    In this study, LiDAR vegetation topography (bare-earth + vegetation height), LiDAR bare-earth topography, the National Elevation Data (NED) set, and Shuttle Radar Terrain Mission (SRTM) measurements are used to develop a statistical model to explore the possibility of extracting vegetation height measurements and accurate high resolution bare-earth topography from SRTM data. The key innovation is to obtain the statistical signature of the vegetation height measurements in the Fourier domain by taking advantage of the well-known linearity in additive properties of the Fourier transform. We demonstrate that the power-law relationship, P(k) α k^(-β), as shown by the bare-earth topography, breaks down approximately at a cross-over wavenumber, k=k_c, due to the vegetation height effect using four different topographic and vegetation study locations in the United States. We document that the vegetation effect mainly dominates the high-frequency contents of the vegetation topography from 2-180 m, 1-60 m, and 1-70 m for the South Fork Eel River, California; Flathead Lake, Montana; and Tenderfoot Creek, Montana, LiDAR data, respectively, and from 1-240 m for 30 m SRTM data for the Jesup, Georgia site. Finally, we demonstrate our ability to obtain a high resolution bare-earth topography with RMSE of 9.6 m, 2.2 m, and 2.9 m and vegetation height with RMSE of 11.0 m (11% error), 4.5 m (12% error), and 1.6 m (8% error) for LiDAR data study sites, whereas for the SRTM data, bare-earth topography and vegetation height are obtained with RMSE values of 5.4 m and 3.1 m, respectively, for the Jesup site. Model Vegetation height

  5. Criticality analysis for weapon disassembly at the Pantex Plant - part I: Bare pits

    Energy Technology Data Exchange (ETDEWEB)

    Knief, R.A. [Ogden Environmental & Energy Services, Albuquerque, NM (United States)

    1997-06-01

    This paper briefly describes criticality investigations for weapon assembly and dismantlement at the Pantex Plant. Results are summarized for calculations performed for safety analyses, radiological hazards assessments, and a study to justify the criticality alarm exemption. Pits and pits in containers were modeled in their most reactive configuration. Criticality calculations were performed with the KENO and MCNP code packages. Configurations involving bare pits were subcritical by a substantial amount even with very conservative model assumptions. Thus, it is concluded that a critical configuration involving the bare pits is not credible.

  6. Bare PCB inspection system with SV-GMR sensor eddy-current testing probe

    OpenAIRE

    Chomsuwan, K.; Yamada, Sotoshi; Iwahara, Masayoshi

    2007-01-01

    This paper describes bare printed circuit board (PCB) inspection based on eddy-current testing (ECT) technique with high scanning speed. A high-frequency ECT probe composed of a meander coil as an exciting coil and the spin-valve giant magnetoresistance (SV-GMR) sensor was fabricated and is proposed. The ECT probe was designed based on crack inspection over flat surface, especially suitable for microdefect detection on high-density bare PCB. The ECT signal detected by the SV-GMR sensor was ac...

  7. Bare Fiber Bragg Gratings embedded into concrete buffer Supercontainer concept for nuclear waste storage

    Energy Technology Data Exchange (ETDEWEB)

    Kinet, Damien; Chah, Karima; Megret, Patrice; Caucheteur, Christophe [Electromagnetism and Telecommunications Department of the University of Mons, 31 Boulevard Dolez, 7000 Mons, (Belgium); Gusarov, Andrei [Belgian Nuclear Research Center, Boeretang 200, 2400 Mol, (Belgium); Faustov, Alexey [Belgian Nuclear Research Center, Boeretang 200, 2400 Mol, (Belgium); Electromagnetisme and Telecommunication Department of the University of Mons, 31 Boulevard Dolez, 7000 Mons, (Belgium); Areias, Lou [Mechanics of Materials and Constructions Department of the Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, (Belgium); European Underground Research Infrastructure for Disposal of nuclear waste In Clay Environment, Boeretang 200, 2400 Mol, (Belgium)

    2015-07-01

    We present the preliminary results obtained with bare fiber Bragg grating-based sensors embedded into half-scale Belgian Supercontainer concept. Being temperature and strain sensitive, some sensors were placed into aluminum tubes to monitor only temperature and results were compared with thermocouples data. The utility of using bare fiber Bragg gratings, knowing that these ones are very fragile, is to have a direct contact between the high alkaline environment of the concrete and silica fibers and to determine its impact over a very long time. (authors)

  8. Root proteome response to growth on tannery waste in three different poplar species with various adaptation abilities

    Directory of Open Access Journals (Sweden)

    Zemleduch-Barylska A.

    2013-04-01

    Full Text Available In our study we compared growth of three poplar clones (Populus tremula ×alba, P. alba ‘Villafranca” and P. nigra on chromium-containing solid tannery waste. Tolerance index of saplings ranged from only 25% for P. nigra up to 80% for P. tremula x alba. Standard morphological, chemical and biochemical analyses also confirmed significant differences in reaction of all tested clones to such growth conditions. Preliminary proteomic study showed an unequal level of changes in protein profiles from roots in different poplars.

  9. Challenging synergistic activity of poplar-bacteria association for the Cd phytostabilization.

    Science.gov (United States)

    C, Cocozza; D, Trupiano; G, Lustrato; G, Alfano; D, Vitullo; A, Falasca; T, Lomaglio; V, De Felice; G, Lima; G, Ranalli; S, Scippa; R, Tognetti

    2015-12-01

    The synergistic activity between plants and microorganisms may contribute to the implementation of proactive management strategies in the stabilization of contaminated sites, although heavy metals, such as cadmium (Cd), are potentially toxic to them. The aim of this study was to evaluate the degree of tolerance to Cd contamination (supplying twice 40 mg kg(-1) of Cd) in poplar cuttings [clone I-214, P. × euramericana (Dode) Guinier] inoculated or not with two concentrations of Serratia marcescens strain (1 × 10(7) CFU/g and 2 × 10(7) CFU/g of potting mix). The response of the plant-bacteria system to excess Cd was investigated with special reference to the structural traits of plants and the functional efficiency of bacteria. Bacterial colonization and substrate components were previously assessed in order to define the best solution for formulating the experimental plant growth media. The tested plant-bacteria association, especially when bacteria were provided in double concentration, stimulated specific tolerance mechanisms to Cd through the promotion of the poplar growth. Inoculated plants produced larger leaves and increased stem diameter, while roots grew longer and wider in Cd-treated plants. The effect of bacterial inoculum on plant growth traits and metal partitioning in plant organs was assessed in order to define the potential of this poplar clone to be a suitable candidate for phytostabilization of Cd-contaminated soil. The final effect of the inoculation with bacteria, which alleviated the metal load and Cd phytotoxicity due to their bioaccumulation ability, suggests promising phytostabilization potential of these plant-bacteria associations.

  10. Isolation and Identification of Phosphobacteria in Poplar Rhizosphere from Different Regions of China

    Institute of Scientific and Technical Information of China (English)

    LIU Hui; WU Xiao-Qin; REN Jia-Hong; YE Jian-Ren

    2011-01-01

    A few soil microorganisms can convert insoluble forms of phosphorus (P) to an accessible form to increase plant yields. The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., phosphate-solubilizing bacteria (PSB) and phosphate-mineralizing bacteria (PMB), in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants. Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797 colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute's phosphate growth medium (NBRIP) containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate, respectively. Then, based on the solubilization of Ca3(PO4)2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium, 15 PSB strains and 7 PMB strains were further determined for their abilities to solubilize Ca3(PO4)2 and to mineralize lecithin. The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L-1 and the 7 PMB strains exhibited organic P-mineralizing abilities varying from 0.32 to 1.56 mg L-1 three days after incubation. Three of PSB strains with the highest P-solubilizing ability, named JW-JS1, JW-JS2 and JW-SX2, were all preliminarily identified as Pseudomonas fluorescens,while two of PMB strains with the highest P-mineralizing ability, named JYZ-SD1 and JYT-JS2, were preliminarily identified as Bacillus cereus and Bacillus subtilis, respectively. All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.

  11. Hypoxia Affects Nitrogen Uptake and Distribution in Young Poplar (Populus × canescens Trees.

    Directory of Open Access Journals (Sweden)

    Bin Liu

    Full Text Available The present study with young poplar trees aimed at characterizing the effect of O2 shortage in the soil on net uptake of NO3- and NH4+ and the spatial distribution of the N taken up. Moreover, we assessed biomass increment as well as N status of the trees affected by O2 deficiency. For this purpose, an experiment was conducted in which hydroponically grown young poplar trees were exposed to hypoxic and normoxic (control conditions for 14 days. 15N-labelled NO3- and NH4+ were used to elucidate N uptake and distribution of currently absorbed N and N allocation rates in the plants. Whereas shoot biomass was not affected by soil O2 deficiency, it significantly reduced root biomass and, consequently, the root-to-shoot ratio. Uptake of NO3- but not of NH4+ by the roots of the trees was severely impaired by hypoxia. As a consequence of reduced N uptake, the N content of all poplar tissues was significantly diminished. Under normoxic control conditions, the spatial distribution of currently absorbed N and N allocation rates differed depending on the N source. Whereas NO3- derived N was mainly transported to the younger parts of the shoot, particularly to the developing and young mature leaves, N derived from NH4+ was preferentially allocated to older parts of the shoot, mainly to wood and bark. Soil O2 deficiency enhanced this differential allocation pattern. From these results we assume that NO3- was assimilated in developing tissues and preferentially used to maintain growth and ensure plant survival under hypoxia, whereas NH4+ based N was used for biosynthesis of storage proteins in bark and wood of the trees. Still, further studies are needed to understand the mechanistic basis as well as the eco-physiological advantages of such differential allocation patterns.

  12. Evaluation on Salt Tolerance of 25 Species of Poplar Cuttings in Lab

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The growth and morphological characteristics of 25 species of poplar were investigated. The cuttings were cultivated in Hoagland Nutrient Solution, which was made with sodium chloride (NaCl) solutions of concentration of 1.00, 3.00, 4.00, 5.00, 6.00, and 8.00 g/L, respectively. Under such salt stress, the new branch length and biomass accumulation of cuttings decreased as the salt concentration increased. The root/shoot ratio of most of species showed an escalation and then reduction tendency. Under low con...

  13. Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees

    DEFF Research Database (Denmark)

    Nielsen, Mette Algreen; Trapp, Stefan; Rein, Arno

    2014-01-01

    The main purpose of this study was to determine typical concentrations of heavy metals (HM) in wood from willows and poplars, in order to test the feasibility of phytoscreening and phytoextraction of HM. Samples were taken from one strongly, one moderately, and one slightly polluted site and from....... Concentrations in wood from the highly polluted site were significantly elevated, compared to references, in particular for willow. The conclusion from these results is that tree coring could be used successfully to identify strongly heavy metal-polluted soil for Cd, Cu, Ni, Zn, and that willow trees were...

  14. Remedial investigation/feasibility study of the Clinch River/Poplar Creek operable unit. Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This volume is in support of the findings of an investigation into contamination of the Clinch River and Poplar Creek near the Oak Ridge Reservation (for more than 50 years, various hazardous and radioactive substances have been released to the environment as a result of operations and waste management activities there). It addresses the quality assurance objectives for measuring the data, presents selected historical data, contains data from several discrete water characterization studies, provides data supporting the sediment characterization, and contains data related to several biota characterization studies.

  15. Three-dimensional (3D) structure model and its parameters for poplar shelterbelts

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The spatial functions of surface area density(vegetative surface area per unit canopy volume) and cubic density(vegetative volume per unit canopy volume) have been used as two three-dimensional(3D) structural descriptors for shelterbelt.The functions were defined by models as a general case.However,sub-models such as surface area,volume,and corresponding distributions were not explicitly defined for poplar trees,which are a dominant woody species in shelterbelts all over China,and this limits applications of the models in China and elsewhere.In order to define and develop these sub-models for shelterbelts,poplar trees were destructively sampled from multiple-row shelterbelts and then were measured for their surface area and volume.Using these measurements,we estimated parameters to define their equations explicitly.Based on the architecture and planting patterns of trees in shelterbelts,the distribution of the surface areas and volumes vertically and across the width for different tree heights were constructed for the three components of trunks,branches and leaves.Incorporating the defined equations into the models,we described the 3D structure of a multiple-row poplar shelterbelt.The results showed that,the spatial change in magnitude of surface area density(0.215-10.131 m2/m3) or cubic density(0.00007-0.04667 m3/m3) in shelterbelts is large and their distributions are not uniform.The assumption for boundary-layer flow modeling efforts that the 3D distribution of shelterbelt structure was uniform is not the case in field.The 3D structure model not only can be used to model the flow field as influenced by each tree component,but also can express the entire aerodynamic characteristics of a shelterbelt.The methodologies and equations that are developed in this study can be applied to estimate the 3D structure of a shelterbelt with a design similar to our studied poplar shelterbelts in terms of species composition and planting patterns.The fitted models can be used to

  16. Best management practices plan for the Lower East Fork Poplar Creek Operable Unit, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This plan was prepared in support of the Phase II Remedial Design Report (DOE/OR/01-1449&D1) and in accordance with requirements under CERCLA to present the plan for best management practices to be followed during the remediation. This document provides the Environmental Restoration Program with information about spill prevention and control, water quality monitoring, good housekeeping practices, sediment and erosion control measures, and inspections and environmental compliance practices to be used during Phase II of the remediation project for the Lower East Fork Poplar Creek Operable Unit.

  17. Biomass yield and fuel characteristics of short-rotation coppice (willow, poplar, empress tree)

    Energy Technology Data Exchange (ETDEWEB)

    Maier, J.; Vetter, R. [Institute for Land Management Compatible to Environmental Requirements, Muellheim (Germany)

    2004-07-01

    In two pedo-climatic different regions in the state of Baden-Wuerttemberg three shortrotation coppices willow, poplar and empress tree were tested with regard to their biomass productivity on arable land and to their properties for energetic use. Between 8 and 13 tons of dry matter per hectare and year could be produced under extensive cultivation conditions, over 15 tons with irrigation. Due to their composition, it can be assumed that their use as solid fuel in a biomass combustor is just as unproblematic as with forest timber. (orig.)

  18. Genome-wide analysis of eukaryote thaumatin-like proteins (TLPs with an emphasis on poplar

    Directory of Open Access Journals (Sweden)

    Duplessis Sébastien

    2011-02-01

    Full Text Available Abstract Background Plant inducible immunity includes the accumulation of a set of defense proteins during infection called pathogenesis-related (PR proteins, which are grouped into families termed PR-1 to PR-17. The PR-5 family is composed of thaumatin-like proteins (TLPs, which are responsive to biotic and abiotic stress and are widely studied in plants. TLPs were also recently discovered in fungi and animals. In the poplar genome, TLPs are over-represented compared with annual species and their transcripts strongly accumulate during stress conditions. Results Our analysis of the poplar TLP family suggests that the expansion of this gene family was followed by diversification, as differences in expression patterns and predicted properties correlate with phylogeny. In particular, we identified a clade of poplar TLPs that cluster to a single 350 kb locus of chromosome I and that are up-regulated by poplar leaf rust infection. A wider phylogenetic analysis of eukaryote TLPs - including plant, animal and fungi sequences - shows that TLP gene content and diversity increased markedly during land plant evolution. Mapping the reported functions of characterized TLPs to the eukaryote phylogenetic tree showed that antifungal or glycan-lytic properties are widespread across eukaryote phylogeny, suggesting that these properties are shared by most TLPs and are likely associated with the presence of a conserved acidic cleft in their 3D structure. Also, we established an exhaustive catalog of TLPs with atypical architectures such as small-TLPs, TLP-kinases and small-TLP-kinases, which have potentially developed alternative functions (such as putative receptor kinases for pathogen sensing and signaling. Conclusion Our study, based on the most recent plant genome sequences, provides evidence for TLP gene family diversification during land plant evolution. We have shown that the diverse functions described for TLPs are not restricted to specific clades but seem

  19. FTIR-ATR-based prediction and modelling of lignin and energy contents reveals independent intra-specific variation of these traits in bioenergy poplars

    Directory of Open Access Journals (Sweden)

    Taylor Gail

    2011-04-01

    Full Text Available Abstract Background There is an increasing demand for renewable resources to replace fossil fuels. However, different applications such as the production of secondary biofuels or combustion for energy production require different wood properties. Therefore, high-throughput methods are needed for rapid screening of wood in large scale samples, e.g., to evaluate the outcome of tree breeding or genetic engineering. In this study, we investigated the intra-specific variability of lignin and energy contents in extractive-free wood of hybrid poplar progenies (Populus trichocarpa × deltoides and tested if the range was sufficient for the development of quantitative prediction models based on Fourier transform infrared spectroscopy (FTIR. Since lignin is a major energy-bearing compound, we expected that the energy content of wood would be positively correlated with the lignin content. Results Lignin contents of extractive-free poplar wood samples determined by the acetyl bromide method ranged from 23.4% to 32.1%, and the calorific values measured with a combustion calorimeter varied from 17260 to 19767 J g-1. For the development of calibration models partial least square regression and cross validation was applied to correlate FTIR spectra determined with an attenuated total reflectance (ATR unit to measured values of lignin or energy contents. The best models with high coefficients of determination (R2 (calibration = 0.91 and 0.90; R2 (cross-validation = 0.81 and 0.79 and low root mean square errors of cross validation (RMSECV = 0.77% and 62 J g-1 for lignin and energy determination, respectively, were obtained after data pre-processing and automatic wavenumber restriction. The calibration models were validated by analyses of independent sets of wood samples yielding R2 = 0.88 and 0.86 for lignin and energy contents, respectively. Conclusions These results show that FTIR-ATR spectroscopy is suitable as a high-throughput method for lignin and energy

  20. Drug-eluting versus bare-metal stents in large coronary arteries

    DEFF Research Database (Denmark)

    Kaiser, Christoph; Galatius, Soeren; Erne, Paul

    2010-01-01

    Recent data have suggested that patients with coronary disease in large arteries are at increased risk for late cardiac events after percutaneous intervention with first-generation drug-eluting stents, as compared with bare-metal stents. We sought to confirm this observation and to assess whether...

  1. TARGET EXCITATION IN BARE ION XE/AR COLLISIONS STUDIED BY ELECTRON TARGET ION COINCIDENCES

    NARCIS (Netherlands)

    DENIJS, G; HOEKSTRA, R; MORGENSTERN, R

    We present electron spectra resulting from collisions of bare ions N-15(7+) and C-13(6+) on Ar and the charge state distribution of target ions resulting from C-13(6+)-Xe collisions. From both type of experiments we find evidence that electron capture accompanied by target excitation is an important

  2. Comparative measurements with seven rainfall simulators on uniform bare fallow land

    NARCIS (Netherlands)

    Iserloh, T.; Ries, J.B.; Cerda, A.; Echeverria, M.T.; Fister, W.; Geissler, C.; Kuhn, N.J.; Leon, F.J.; Peters, P.; Schindewolf, M.; Schmidt, J.; Scholten, T.; Seeger, K.M.

    2013-01-01

    To assess the influence of rainfall simulator type and plot dimensions on runoff and erosion, seven small portable rainfall simulators from Freiberg, Tubingen, Trier (all Germany), Valencia, Zaragoza (both Spain), Basel (Switzerland) and Wageningen (the Netherlands) were compared on a prepared bare

  3. A new notion of soundness in bare public-key model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yunlei; ZHU Hong

    2003-01-01

    A new notion of soundness in bare public-key (BPK) model is presented. This new notion just lies in between one-time soundness and sequential soundness and its reasonableness is justified in the context of resettable zero-knowledge when resettable zero-knowledge prover is implemented by smart card.

  4. Graph segmentation and support vector machines for bare earth classification from lidar

    Science.gov (United States)

    Shorter, Nicholas S.; Smith, O'Neil; Smith, Philip; Rahmes, Mark

    2014-06-01

    A novel approach using a support vector machine (SVM) is proposed to classify bare earth points in LiDAR point clouds. Using graph based segmentation, the LiDAR point cloud is segmented into a set of topological components. Several features establishing relationships from those components to their neighboring components are formulated. The SVM is then trained on the segment features to establish a model for the classification of bare earth and non bare earth points. Quantitative results are presented for training and testing the proposed SVM classifier on the ISPRS data set. Using the ISPRS data set as a training set, qualitative results are presented by testing the proposed SVM classifier on data downloaded from Open Topography; which covers a variety of different landscapes and building structures in Frazier Park, California. Despite the data being captured from different sensors, and collected from scenes with different terrain types and building structures, the results shown were processed with no parameter changes. Furthermore, a confidence value is returned indicating how well the unforeseen data fits the SVM's trained model for bare earth recognition.

  5. Patients' perceptions of doctors' clothing: should we really be 'bare below the elbow'?

    Science.gov (United States)

    Bond, L; Clamp, P J; Gray, K; Van Dam, V

    2010-09-01

    In September 2007, the Department of Health published Uniforms and Workwear: an Evidence Base for Guiding Local Policy. Following this, most National Health Service trusts imposed a 'bare below the elbow' dress code policy, with clinical staff asked to remove ties, wristwatches and hand jewellery and to wear short-sleeved tops. There is currently no evidence linking dress code to the transmission of hospital-acquired infection. We designed the current survey to assess patients' perceptions of doctors' appearance, with specific reference to the 'bare below the elbow' policy. A questionnaire showing photographs of a doctor in three different types of attire ('scrubs', formal attire and 'bare below the elbow') were used to gather responses from 80 in-patients and 80 out-patients in the ENT department. Patients were asked which outfit they felt was the most hygienic, the most professional and the easiest identification of the person as a doctor. They were also asked to indicate their overall preference. Formal attire was considered most professional and the easiest identification that the person was a doctor. Scrubs were considered most hygienic. Respondents' overall preference was divided between scrubs and formal clothes. 'Bare below the elbow' attire received the lowest votes in all categories. This finding raises significant questions about the Department of Health policy in question. The authors suggest that an alternative policy should be considered, with scrubs worn for in-patient situations and formal attire during out-patient encounters.

  6. EAARL-B coastal topography: Chandeleur Islands, Louisiana, 2012: seamless (bare earth and submerged)

    Science.gov (United States)

    Wright, C. Wayne; Klipp, Emily S.; Kranenburg, Christine J.; Troche, Rodolfo J.; Fredericks, Alexandra M.; Masessa, Melanie L.; Nagle, David B.

    2015-01-01

    These remotely sensed, geographically referenced elevation measurements of light detection and ranging (lidar)-derived seamless (bare-earth and submerged) topography datasets were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

  7. Bare Forms and Lexical Insertions in Code-Switching: A Processing-Based Account

    Science.gov (United States)

    Owens, Jonathan

    2005-01-01

    Bare forms (or [slashed O] forms), uninflected lexical L2 insertions in contexts where the matrix language expects morphological marking, have been recognized as an anomaly in different approaches to code-switching. Myers-Scotton (1997, 2002) has explained their existence in terms of structural incongruity between the matrix and embedded…

  8. Bare Pedagogy and the Scourge of Neoliberalism: Rethinking Higher Education as a Democratic Public Sphere

    Science.gov (United States)

    Giroux, Henry A.

    2010-01-01

    A new form of bare pedagogy is emerging in higher education focused on market-driven competitiveness and even militaristic goal-setting, while critical pedagogy, with its emphasis on the hard work of critical analysis, moral judgments, and social responsibility (critical pedagogy that goes to the very heart of what it means to address real…

  9. Characterization of diamond film and bare metal photocathodes as a function of temperature and surface preparation

    Energy Technology Data Exchange (ETDEWEB)

    Shurter, R.P.; Moir, D.C.; Devlin, D.J.

    1996-07-01

    High current photocathodes using bare metal and polycrystalline diamond films illuminated by ultraviolet lasers are being developed at Los Alamos for use in a new generation of linear induction accelerators. These photocathodes must be able to produce multiple 60 ns pulses separated by several to tens of nanoseconds. The vacuum environment in which the photocathodes must operate is 10{sup -5} torr.

  10. EAARL Coastal Topography—Northern Assateague Island National Seashore, Maryland and Virginia, 2003: Bare earth

    Science.gov (United States)

    Kranenburg, Christine; Fredericks, Alexandra M.; Nagle, David B.

    2017-01-01

    These datasets, prepared by the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in collaboration with the National Park Service, provide lidar-derived bare-earth topography for Northern Assateague Island National Seashore, Maryland and Virginia. Elevation measurements were acquired by the Experimental Advanced Airborne Research Lidar (EAARL) during February 2003.

  11. Bare Quark Stars or Naked Neutron Stars: The Case of RX J1856.5-3754

    CERN Document Server

    Turolla, R; Drake, J J; Turolla, Roberto; Zane, Silvia; Drake, Jeremy J.

    2004-01-01

    In a cool neutron star (T 10^13 G), a phase transition may occur in the outermost layers. As a consequence the neutron star becomes `bare', i.e. no gaseous atmosphere sits on the top of the crust. The surface of cooling, bare neutron stars not necessary gives off blackbody radiation because of the strong suppression in the emissivity at energies below the electron plasma frequency \\omega_p. Since \\omega_p~1 keV under the conditions typical of the dense electron gas in the condensate, the emission from a T~100 eV bare neutron star will be substantially depressed with respect to that of a perfect Planckian radiator at most energies. Here we present a detailed analysis of the emission properties of a bare neutron star. In particular, we derive the surface emissivity for a Fe composition in a range of magnetic fields and temperatures representative of cooling isolated neutron stars, like RX J1856.5-3754. We find that the emitted spectrum is strongly dependent on the electron conductivity in the solid surface lay...

  12. Drug-eluting versus bare-metal stents in large coronary arteries

    DEFF Research Database (Denmark)

    Kaiser, Christoph; Galatius, Soeren; Erne, Paul

    2010-01-01

    Recent data have suggested that patients with coronary disease in large arteries are at increased risk for late cardiac events after percutaneous intervention with first-generation drug-eluting stents, as compared with bare-metal stents. We sought to confirm this observation and to assess whether...... this increase in risk was also seen with second-generation drug-eluting stents....

  13. Long-Term Safety of Drug-Eluting and Bare-Metal Stents

    DEFF Research Database (Denmark)

    Palmerini, Tullio; Benedetto, Umberto; Biondi-Zoccai, Giuseppe;

    2015-01-01

    BACKGROUND: Previous meta-analyses have investigated the relative safety and efficacy profiles of different types of drug-eluting stents (DES) and bare-metal stents (BMS); however, most prior trials in these meta-analyses reported follow-up to only 1 year, and as such, the relative long-term safe...

  14. Introducing the Notion of Bare and Effective Mass via Newton's Second Law of Motion

    Science.gov (United States)

    Pinto, Marcus Benghi

    2007-01-01

    The concepts of bare and effective mass are widely used within modern physics. Their meaning is discussed in advanced undergraduate and graduate courses such as solid state physics, nuclear physics and quantum field theory. Here I discuss how these concepts may be introduced together with the discussion of Newton's second law of motion. The…

  15. Drug-eluting stents versus bare-metal stents for acute coronary syndrome

    DEFF Research Database (Denmark)

    Feinberg, Joshua; Nielsen, Emil Eik; Greenhalgh, Janette

    2017-01-01

    not included all relevant randomised clinical trials. OBJECTIVES: To assess the benefits and harms of drug-eluting stents versus bare-metal stents in people with acute coronary syndrome. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, SCI-EXPANDED...

  16. Analyses of protein corona on bare and silica-coated gold nanorods against four mammalian cells.

    Science.gov (United States)

    Das, Minakshi; Yi, Dong Kee; An, Seong Soo A

    2015-01-01

    The purpose of this study was to investigate the mechanisms responsible for the toxic effects of gold nanorods (AuNRs). Here, a comprehensive study was performed by examining the effects of bare (uncoated) AuNRs and AuNRs functionalized with silica (SiO2-AuNRs) against various mammalian cell lines, including cervical cancer cells, fibroblast cells, human umbilical vein endothelial cells, and neuroblastoma cells. The interactions between AuNRs and mammalian cells were investigated with cell viability and mortality assays. Dihydrorhodamine-123 assay was carried out for evaluating reactive oxygen species (ROS) generation, along with mass spectroscopy analysis for determining the composition of the protein corona. Our results suggest that even the lowest concentrations of AuNRs (0.7 μg/mL) induced ROS production leading to cell mortality. On the other hand, cellular viability and ROS production were maintained even at a higher concentration of SiO2-coated AuNRs (12 μg/mL). The increased production of ROS by AuNRs seemed to cause the toxicity observed in all four mammalian cell types. The protein corona on the bare AuNRs did not appear to reduce ROS generation; however, different compositions of the protein corona on bare and SiO2-coated AuNRs may affect cellular behavior differently. Therefore, it was determined that SiO2-coated AuNRs would be more advantageous than bare AuNRs for cellular applications.

  17. Validity of arthroscopic measurement of glenoid bone loss using the bare spot

    Directory of Open Access Journals (Sweden)

    Miyatake K

    2014-03-01

    Full Text Available Katsutoshi Miyatake, Yoshitsugu Takeda, Koji Fujii, Tomoya Takasago, Toshiyuki Iwame Department of Orthopaedic Surgery, Tokushima Red Cross Hospital, Komatsushima, Tokushima, Japan Purpose: Our aim was to test the validity of using the bare spot method to quantify glenoid bone loss arthroscopically in patients with shoulder instability. Methods: Twenty-seven patients with no evidence of instability (18 males, nine females; mean age 59.1 years were evaluated arthroscopically to assess whether the bare spot is consistently located at the center of the inferior glenoid. Another 40 patients with glenohumeral anterior instability who underwent shoulder arthroscopy (30 males, ten females; mean age 25.9 years were evaluated for glenoid bone loss with preoperative three-dimensional computed tomography (3D-CT and arthroscopic examination. In patients without instability, the distances from the bare spot of the inferior glenoid to the anterior (Da and posterior (Dp glenoid rim were measured arthroscopically. In patients with instability, we compared the percentage glenoid bone loss calculated using CT versus arthroscopic measurements. Results: Among patients without instability, the bare spot could not be identified in three of 27 patients. Da (9.5±1.2 mm was smaller than Dp (10.1±1.5 mm, but it was not significantly different. However, only 55% of glenoids showed less than 1 mm of difference between Da and Dp, and 18% showed more than 2 mm difference in length. The bare spot could not be identified in five of 40 patients with instability. Pearson's correlation coefficient showed significant (P<0.001 and strong (R2=0.63 correlation in percentage glenoid bone loss between the 3D-CT and arthroscopy method measurements. However, in ten shoulders (29%, the difference in percentage glenoid bone loss between 3D-CT and arthroscopic measurements was greater than 5%. Conclusion: The bare spot was not consistently located at the center of the inferior glenoid

  18. Differential expression profiles of poplar MAP kinase kinases in response to abiotic stresses and plant hormones, and overexpression of PtMKK4 improves the drought tolerance of poplar.

    Science.gov (United States)

    Wang, Lei; Su, Hongyan; Han, Liya; Wang, Chuanqi; Sun, Yanlin; Liu, Fenghong

    2014-07-15

    Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules that play essential roles in plant growth, development and stress response. MAPK kinases (MAPKKs), which link MAPKs and MAPKK kinases (MAPKKKs), are integral in mediating various stress responses in plants. However, to date few data about the roles of poplar MAPKKs in stress signal transduction are available. In this study, we performed a systemic analysis of poplar MAPKK gene family expression profiles in response to several abiotic stresses and stress-associated hormones. Furthermore, Populus trichocarpa MAPKK4 (PtMKK4) was chosen for functional characterization. Transgenic analysis showed that overexpression of the PtMKK4 gene remarkably enhanced drought stress tolerance in the transgenic poplar plants. The PtMKK4-overexpressing plants also exhibited much lower levels of H2O2 and higher antioxidant enzyme activity after exposure to drought stress compared to the wide type lines. Besides, some drought marker genes including PtP5CS, PtSUS3, PtLTP3 and PtDREB8 exhibited higher expression levels in the transgenic lines than in the wide type under drought conditions. This study provided valuable information for understanding the putative functions of poplar MAPKKs involved in important signaling pathways under different stress conditions.

  19. The influence of silane coupling agent and poplar particles on the wet-tability, surface roughness, and hardness of UF-bonded wheat straw (Triticum aestivum L.)/poplar wood particleboard

    Institute of Scientific and Technical Information of China (English)

    Seyedeh Masoumeh Hafezi; Kazem Doosthoseini

    2014-01-01

    We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties (wettability and surface roughness) and hardness of parti-cleboard made from UF-bonded wheat straw (Triticum aestivum L.) combined with poplar wood as affected by silane coupling agent content and straw/poplar wood particle ratios. We manufactured one-layered particleboard panels at four different ratios of straw to poplar wood par-ticles (0%, 15%, 30% and 45% wheat straw) and silane coupling agent content at three levels of 0, 5% and 10%. Roughness measurements, average roughness (Ra), mean peak-to-valley height (Rz), and root mean square roughness (Rq) were measured on unsanded samples by using a fine stylus tracing technique. We obtained contact angle measurements by using a goniometer connected to a digital camera and computer sys-tem. Boards containing greater amounts of poplar particles had superior hardness compared to control samples and had lower wettability. Panels made with higher amounts of silane had lower Rq values.

  20. The contribution of vegetation cover and bare soil to pixel reflectance in an arid ecosystem

    Science.gov (United States)

    Steele, C. M.; Smith, A.; Campanella, A.; Rango, A.

    2008-12-01

    The heterogeneity of vegetation and soils in arid and semi-arid environments complicates the analysis of medium spatial resolution remotely sensed imagery. A single pixel may contain several different types of vegetation, as well as a sizeable proportion of bare soil. We have used linear mixture modeling to explore the contribution of vegetation cover and bare soil to pixel reflectance. In October, 2006, aerial imagery (0.25 m spatial resolution) was acquired for our study sites in the Jornada Experimental Range, southern New Mexico. Imagery was also acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for June and November, 2006. These data corresponded with pre- and post monsoon conditions. Object-based feature extraction was used to classify the aerial imagery to shrub, grass and bare ground cover classes. Percent cover was then calculated for each cover class. Visible-near-infrared and shortwave infrared ASTER reflectance data from both dates were combined into a single 18-band dataset (30 m spatial resolution). A vector overlay from the classification results of the aerial imagery was used to define pure endmember pixels in the ASTER imagery. Estimates of the proportions of shrub, grass and bare ground cover from the linear mixture modeling approach were compared with cover calculated using feature extraction from the aerial imagery. The results indicate that reflectance in ASTER pixels is likely to be a linear combination of the cover proportions of the three main cover types (shrubs, grass, bare ground). However, noticeable outliers in the relationship between cover calculated from each method, indicate there may be other variables that affect the accuracy with which we can estimate cover using linear mixture modeling.

  1. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  2. EVALUATION AND IDENTIFICATION OF WALNUT HEARTWOOD EXTRACTIVES FOR PROTECTION OF POPLAR WOOD

    Directory of Open Access Journals (Sweden)

    Seyyed Khalil Hosseini Hashemi

    2011-02-01

    Full Text Available Walnut (Juglans regia L. heartwood extractives were identified and their potential for protection of poplar wood was evaluated. Test specimens were prepared from poplar wood (Populus nigra L. to meet BS 838:1961 requirements. Samples were impregnated with heartwood extractive solution (1.5, 2.5, and 3.5% w/w in ethanol-toluene, followed by 5 hours vacuum desiccator technique to reach complete saturation. Impregnated specimens were exposed to white-rot fungus (Trametes versicolor for 14 weeks according to BS 838:1961 applying the kolle-flask method. The weight loss of samples was determined after exposure to white-rot fungus. The highest weight loss (36.96% was observed for untreated control samples and the lowest weight loss (30.40% was measured in samples treated with 1.5% extractives solution. The analyses of the extracts using GC/MS indicated that major constituents are benzoic acid,3,4,5-tri(hydroxyl and gallic acid (44.57 %. The two toxic components in the heartwood are juglone (5.15 % and 2,7-dimethylphenantheren (5.81 %.

  3. A model of supplying poplar wood for Iranian paper & wood factories

    Institute of Scientific and Technical Information of China (English)

    Majid Azizi

    2008-01-01

    The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran.Due to the destruction of the forests and lack of proper plantation,replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories.A hierarchy was used to prioritize benefits,opportunities,costs and risks (BOCR) using the Analytic Hierarchy Process (AHP) ratings approach.To evaluate the "control criteria" of the system,a control hierarchy was also created and prioritized by applying the Analytic Network Process (ANP).A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANP.The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives (factory procurement,external procurement and mix procurement).

  4. Mycorrhizal Fungal Community of Poplars Growing on Pyrite Tailings Contaminated Site near the River Timok

    Directory of Open Access Journals (Sweden)

    Marina Katanić

    2015-06-01

    Full Text Available Background and Purpose: Mycorrhizal fungi are of high importance for functioning of forest ecosystems and they could be used as indicators of environmental stress. The aim of this research was to analyze ectomycorrhizal community structure and to determine root colonization rate with ectomycorrhizal, arbuscular mycorrhizal and endophytic fungi of poplars growing on pyrite tailings contaminated site near the river Timok (Eastern Serbia. Materials and Methods: Identification of ectomycorrhizal types was performed by combining morphological and anatomical characterization of ectomycorrhizae with molecular identification approach, based on sequencing of the nuclear ITS rRNA region. Also, colonization of poplar roots with ectomycorrhizal, arbuscular mycorrhizal and dark septated endophytic fungi were analysed with intersection method. Results and Conclusions: Physico-chemical analyses of soil from studied site showed unfavourable water properties of soil, relatively low pH and high content of heavy metals (copper and zinc. In investigated samples only four different ectomycorrhizal fungi were found. To the species level were identified Thelephora terrestris and Tomentella ellisi, while two types remained unidentified. Type Thelephora terrestris made up 89% of all ectomycorrhizal roots on studied site. Consequently total values of Species richness index and Shannon-Weaver diversity index were 0.80 and 0.43, respectively. No structures of arbuscular mycorrhizal fungi were recorded. Unfavourable environmental conditions prevailing on investigated site caused decrease of ectomycorrhizal types diversity. Our findings point out that mycorrhyzal fungal community could be used as an appropriate indicator of environmental changes.

  5. Insect-resistant mechanism of transgenic triploid of Chinese white poplar

    Institute of Scientific and Technical Information of China (English)

    Yuan Shengliang; Gao Baojia; Zhang Na

    2006-01-01

    The activities of antidotal enzymes and digestive enzymes of Clostera anachoreta (Fabricius) instar larvae,feeding on leaves of three kinds of insect-resistant clones of transgenic triploid of Chinese white poplar,after 4,12,24,48,72 and 96 h,were investigated.The results showed that,feeding on clone 7,the activity of esterase,carboxylesterase,and mixed-function oxidases in the midgut of the larvae was very much decreased.Feeding on clone 10,those results were less than those of clone 7 and there were few changes on the larvae,which fed on clone 26.The changes of the amylase in the midgut of larvae were the same as those described above.However,the activities of glutathione S-transferase and proteinase were complex,increased markedly after 24 h feeding on clone 7,and then declined rapidly.The same changes were taking place on the larvae feeding on clone 10.There were many slight changes in glutathione S-transferase of the larvae,feeding on clone 26;no changes occurred in the proteinases of the midgut.Thus,the antidotal enzymes and digestive enzymes in the midgut of the larvae were inhibited.This may be the main mechanism of the transgenic triploid of Chinese white poplar.

  6. Effect of Thermal Treatment of Veneer on Formaldehyde Emission of Poplar Plywood

    Directory of Open Access Journals (Sweden)

    Takato Nakano

    2013-01-01

    Full Text Available A large amount of poplar plywood is now being imported into Japan from China, and as a result, formaldehyde emitted from this plywood represents an undesirable chemical that must be controlled using a chemical catching agent. The aim of this study is to find an approach to reduce the formaldehyde emission of poplar plywood using thermal treatment without employing any chemicals. The experimental results obtained show that heating veneer sheets in the temperature range of 150 °C to 170 °C effectively reduced the formaldehyde emission of plywood, without diminishing the mechanical properties of the veneer. By applying Langmuir’s theory and Hailwood-Horrobin theory to the adsorption isotherm obtained in this study, the relationship between the formaldehyde emission of plywood and the adsorption properties of veneer as a material is discussed. When veneer sheets were heated in the temperature range of 150 °C to 170 °C, the amount of hydrated water (monomolecular layer decreased slightly and that of dissolved water (polymolecular layer did not change. It is hypothesized that the formaldehyde emission of plywood is related to the condition of the adsorption site of the wood.

  7. Chemical Profiles of Wood Components of Poplar Clones for Their Energy Utilization

    Directory of Open Access Journals (Sweden)

    Danica Kačíková

    2012-12-01

    Full Text Available Selected and tested poplar clones are very suitable biomass resources for various applications such as biofuels, the pulp and paper industry as well as chemicals production. In this study, we determined the content of lignin, cellulose, holocellulose, and extractives, syringyl to guaiacyl (S/G ratio in lignin, and also calculated higher heating values (HHV among eight examined clones of Populus grown on three different experimental sites. The highest lignin content for all the examined sites was determined in ‘I-214’ and ‘Baka 5’ clones, whereas the highest content of extractives was found in ‘Villafranca’ and ‘Baka 5’ clones. The highest S/G ratio for all the examined sites was determined in ‘Villafranca’ and ‘Agathe F’ clones. The chemical profiles of main wood components, extractives, and the S/G ratio in lignin were also influenced by both the experimental site and the clone × site interaction. Higher heating values, derived from calculations based on the contents of lignin and extractives (or lignin only, were in close agreement with the previously published data. The highest heating values were found for ‘Baka 5’ and ‘I-214’ clones. The optimal method of poplar biomass utilization can be chosen on basis of the lignocellulosics chemical composition and the S/G ratio in lignin.

  8. S-nitroso-proteome in poplar leaves in response to acute ozone stress.

    Directory of Open Access Journals (Sweden)

    Elisa Vanzo

    Full Text Available Protein S-nitrosylation, the covalent binding of nitric oxide (NO to protein cysteine residues, is one of the main mechanisms of NO signaling in plant and animal cells. Using a combination of the biotin switch assay and label-free LC-MS/MS analysis, we revealed the S-nitroso-proteome of the woody model plant Populus x canescens. Under normal conditions, constitutively S-nitrosylated proteins in poplar leaves and calli comprise all aspects of primary and secondary metabolism. Acute ozone fumigation was applied to elicit ROS-mediated changes of the S-nitroso-proteome. This treatment changed the total nitrite and nitrosothiol contents of poplar leaves and affected the homeostasis of 32 S-nitrosylated proteins. Multivariate data analysis revealed that ozone exposure negatively affected the S-nitrosylation status of leaf proteins: 23 proteins were de-nitrosylated and 9 proteins had increased S-nitrosylation content compared to the control. Phenylalanine ammonia-lyase 2 (log2[ozone/control] = -3.6 and caffeic acid O-methyltransferase (-3.4, key enzymes catalyzing important steps in the phenylpropanoid and subsequent lignin biosynthetic pathways, respectively, were de-nitrosylated upon ozone stress. Measuring the in vivo and in vitro phenylalanine ammonia-lyase activity indicated that the increase of the phenylalanine ammonia-lyase activity in response to acute ozone is partly regulated by de-nitrosylation, which might favor a higher metabolic flux through the phenylpropanoid pathway within minutes after ozone exposure.

  9. Drought-induced xylem pit membrane damage in aspen and balsam poplar.

    Science.gov (United States)

    Hillabrand, Rachel M; Hacke, Uwe G; Lieffers, Victor J

    2016-10-01

    Drought induces an increase in a tree's vulnerability to a loss of its hydraulic conductivity in many tree species, including two common in western Canada, trembling aspen (Populus tremuloides) and balsam poplar (Populus balsamifera). Termed 'cavitation fatigue' or 'air-seeding fatigue', the mechanism of this phenomenon is not well understood, but hypothesized to be a result of damage to xylem pit membranes. To examine the validity of this hypothesis, the effect of drought on the porosity of pit membranes in aspen and balsam poplar was investigated. Controlled drought and bench dehydration treatments were used to induce fatigue and scanning electron microscopy (SEM) was used to image pit membranes for relative porosity evaluations from air-dried samples after ethanol dehydration. A significant increase in the diameter of the largest pore was found in the drought and dehydration treatments of aspen, while an increase in the percentage of porous pit membranes was found in the dehydration treatments of both species. Additionally, the location of the largest pore per pit membrane was observed to tend toward the periphery of the membrane.

  10. Estimation of the yield of poplars in plantations of fast-growing species within current results

    Directory of Open Access Journals (Sweden)

    Martin Fajman

    2009-01-01

    Full Text Available Current results are presented of allometric yield estimates of the poplar short rotation coppice. According to a literature review it is obvious that yield estimates, based on measurable quantities of a growing stand, depend not only on the selected tree specie or its clone, but also on the site location. The Jap-105 poplar clone (P. nigra x P. maximowiczii allometric relations were analyzed by regression methods aimed at the creation of the yield estimation methodology at a testing site in Domanínek. Altogether, the twelve polynomial dependences of particular measured quantities approved the high empirical data conformity with the tested regression model (correlation index from 0.9033 to 0.9967. Within the forward stepwise regression, factors were selected, which explain best examined estimates of the total biomass DM; i.e. d.b.h. and stem height. Furthermore, the KESTEMONT’s (1971 mo­del was verified with a satisfying conformity as well. Approving presented yield estimation methods, the presented models will be checked in a large-scale field trial.

  11. Computer Simulation of Fiber Length and Width Distribution for Two Poplar Woods

    Institute of Scientific and Technical Information of China (English)

    ZHANGDongmei; HOUZhuqiang; GUANNing

    2004-01-01

    Computer simulation was carried out on fiber length and width for plantation-grown Chinese white poplar (Populus tomentosa Cart. clone) and plantation-grown poplar 1-72 (P. x eurumericana (Dode) Guiner cv.). Skewness and kurtosis of measured results exhibited that distributions of the fiber length and width departured from normal distribution. Three-parameter Weibull density function was used in this investigation and the corresponding program was written with Turbo C. The results showed that profiles of simulated length and width histograms were similar to ones of measured histograms, and that there was a pretty good agreement between simulated and measured means of fiber length and width. There was a little influence on the simulated means from seed used in random number generator and number of simulated variables. That indicated that the simulation was steady when the seed and the number were altered. Different histograms can be obtained with different values of the location, the shape, and the scale parameter corresponding to different values of the minimum, the mean, and the standard deviation for fiber length and width. The simulation presented here can be used as a tool for the studies on the variations in fiber morphology.

  12. Tulip-poplar leaf diffusion resistance calculated from stomatal dimensions and varying environmental parameters

    Energy Technology Data Exchange (ETDEWEB)

    McConathy, R.K.

    1983-03-01

    The study describes the gradients of stomatal size and density in the crown of a mature forest-grown tulip-poplar (Liriodendron tulipifera L.) in eastern Tennessee. These data are used to predict leaf resistance to vapor diffusion in relation to stomatal width and boundary layer resistance. Stomatal density on individual leaves did not vary, but density increased with increasing crown height. Stomatal size decreased with increasing height of leaves within the crown. Stomatal size and density variations interacted to result in a constant number of stomata per leaf at all crown heights. Stomatal diffusive resistance values calculated from stomatal measurements and varying environmental parameters indicated that stomatal resistance controlled transpiration water losses only at small apertures (<0.6 ..mu..m). Boundary layer resistance was controlling at large stomatal apertures (>0.6 ..mu..m) and at low wind speeds (approx.100 cm/s). Under normal forest conditions tulip-poplar stomatal resistance exercised more control over transpiration than did boundary layer resistance.

  13. Nonmicrobial aerobic methane emission from poplar shoot cultures under low-light conditions.

    Science.gov (United States)

    Brüggemann, Nicolas; Meier, Rudolf; Steigner, Dominik; Zimmer, Ina; Louis, Sandrine; Schnitzler, Jörg-Peter

    2009-06-01

    The aerobic formation of methane in plants has been reported previously, but has been questioned by a number of researchers. Recently, isotopic evidence demonstrated that ultraviolet irradiation and heating lead to photochemical or thermal aerobic methane formation mainly from plant pectin in the absence of microbial methane production. However, the origin of aerobic methane formation from plant material observed under low temperature and low-light/dark conditions is still unclear. Here we show that Grey poplar (Populus × canescens, syn. Populus tremula × Populus alba) plants derived from cell cultures under sterile conditions released 13C-labeled methane under low-light conditions after feeding the plants with 13CO2. Molecular biological analysis proved the absence of any microbial contamination with known methanogenic microorganisms and ruled out the possibility that methane emission from our poplar shoot cultures under aerobic low-light/dark and ambient temperature conditions could be of microbial origin. The CH4 release rates in our experiment were in the range of 0.16-0.7 ng g-1 DW h-1, adding evidence to the growing opinion that the quantitative role of aerobic methane emissions from plants in the global methane budget, at least from cold temperate or boreal regions, is only of minor importance.

  14. Physical and chemical characteristics of products from the torrefaction of yellow poplar (Liriodendron tulipifera).

    Science.gov (United States)

    Kim, Young-Hun; Lee, Soo-Min; Lee, Hyoung-Woo; Lee, Jae-Won

    2012-07-01

    We investigated the characteristics of torrefied yellow poplar (Liriodendron tulipifera) depending on reaction time (30 min) and temperature (240-280 °C). The thermogravimetric, grindability and calorific value of torrefied biomass were analyzed. As the torrefaction temperature increased, the carbon content of torrefied biomass increased from 49.50% to 54.42%, while the hydrogen and oxygen contents decreased from 6.09% to 5.65% and 28.71% to 26.61%, respectively. The highest calorific value was 1233 kJ/kg when torrefaction was performed at 280 °C for 30 min. An overall increase in energy density and decrease in mass and energy yield was observed with the increase in torrefaction temperature. The analysis of thermal decomposition demonstrated that the hemicelluloses contained in torrefied biomass decreased with increasing torrefaction temperature, whereas cellulose and lignin were only slightly affected. The grindability of torrefied biomass was significantly improved when torrefaction was performed at high temperature. Torrefaction of yellow poplar improved the chemical and physical fuel properties of the biomass.

  15. Genome-Wide Identification and in Silico Analysis of Poplar Peptide Deformylases

    Directory of Open Access Journals (Sweden)

    Chuan-Ping Yang

    2012-04-01

    Full Text Available Peptide deformylases (PDF behave as monomeric metal cation hydrolases for the removal of the N-formyl group (Fo. This is an essential step in the N-terminal Met excision (NME that occurs in these proteins from eukaryotic mitochondria or chloroplasts. Although PDFs have been identified and their structure and function have been characterized in several herbaceous species, it remains as yet unexplored in poplar. Here, we report on the first identification of two genes (PtrPDF1A and PtrPDF1B respectively encoding two putative PDF polypeptides in Populus trichocarpa by genome-wide investigation. One of them (XP_002300047.1 encoded by PtrPDF1B (XM_002300011.1 was truncated, and then revised into a complete sequence based on its ESTs support with high confidence. We document that the two PDF1s of Populus are evolutionarily divergent, likely as a result of independent duplicated events. Furthermore, in silico simulations demonstrated that PtrPDF1A and PtrPDF1B should act as similar PDF catalytic activities to their corresponding PDF orthologs in Arabidopsis. This result would be value of for further assessment of their biological activities in poplar, and further experiments are now required to confirm them.

  16. Herbivore-induced volatile emission in black poplar: regulation and role in attracting herbivore enemies.

    Science.gov (United States)

    Clavijo McCormick, Andrea; Irmisch, Sandra; Reinecke, Andreas; Boeckler, G Andreas; Veit, Daniel; Reichelt, Michael; Hansson, Bill S; Gershenzon, Jonathan; Köllner, Tobias G; Unsicker, Sybille B

    2014-08-01

    After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts.

  17. Effects of poplar buds as an alternative to propolis on postharvest diseases control of strawberry fruits.

    Science.gov (United States)

    Yang, Shuzhen; Zhou, Yefeng; Ye, Junli; Fan, Gang; Peng, Litao; Pan, Siyi

    2016-04-01

    Botrytis cinerea and Rhizopus stolonifer, two main postharvest pathogens, cause great loss of strawberry fruits. Here, the effects of poplar buds extracts, a main plant source for Chinese propolis, on disease control were investigated in vitro and in vivo. The HPLC profile of poplar buds ethanol extract (PBEE) was almost identical to that of propolis ethanol extract (PEE), with the active flavonoids identified as pinocembrin, chrysin and galangin. PBEE exhibited similar inhibitory activities on spore germination of both pathogens compared with PEE, and PBEE also strongly inhibited the mycelial growth of the pathogens. In vivo, PBEE could effectively reduce decay of strawberry fruits stored at 13 °C. Although the weight loss was slightly increased, the contents of total soluble solid, titritable acid, vitamin C and total anthocyanins were significantly higher in PBEE treated fruits than those of the control. PBEE had the similar antifungal activity with propolis and had great potential as an alternative to propolis to control strawberry fruits diseases. © 2015 Society of Chemical Industry.

  18. Superior supercapacitive performance of hollow activated carbon nanomesh with hierarchical structure derived from poplar catkins

    Science.gov (United States)

    Su, Xiao-Li; Cheng, Ming-Yu; Fu, Lin; Yang, Jing-He; Zheng, Xiu-Cheng; Guan, Xin-Xin

    2017-09-01

    The hollow activated carbon nanomesh (PCACM) with a hierarchical porous structure is derived from biowaste-poplar catkins by in-situ calcination etching with Ni(NO3)2·6H2O and KOH in N2 flow combined with an acid dissolution technique. This procedure not only inherits the natural tube morphology of poplar catkins, but also generates a fascinating nanomesh structure on the walls. PCACM possesses a large specific surface area (SBET = 1893.0 m2 g-1) and high total pore volume (Vp = 1.495 cm3 g-1), and displays an exciting meso-macoporous structure with a concentrated pore size distribution of 4.53 nm. The specific capacitance of PCACM is as high as 314.6 F g-1 at 1.0 A g-1 when used as the electrode materials for supercapacitor. Furthermore, the symmetric supercapacitor of PCACM with 1.0 M Na2SO4 solution as the electrolyte displays a high energy density of 20.86 Wh kg-1 at a power density of 180.13 W kg-1 within a wide voltage rage of 0-1.8 V, which is comparable or even obviously higher than those of other biomass derived carbon reported. It is noteworthy that PCACM also exhibits superior cycling stability and coulombic efficiency. The excellent electrochemical behaviors enable PCACM to be a promising electrode material for supercapacitors.

  19. Anaerobic digestion of poplar processing residues for methane production after alkaline treatment.

    Science.gov (United States)

    Yao, Yiqing; He, Mulan; Ren, Yubing; Ma, Liying; Luo, Yang; Sheng, Hongmei; Xiang, Yun; Zhang, Hua; Li, Qien; An, Lizhe

    2013-04-01

    Poplar processing residues were used for methane production by anaerobic digestion after alkaline treatment and methane production was measured. The highest methane production of 271.9 L/kg volatile solid (VS) was obtained at conditions of 35 g/L and 5.0% NaOH, which was 113.8% higher than non-alkaline treated samples, and 28.9% higher than that of corn straw, which is the conventional anaerobic digestion material in China. The maximal enhancement of 275.5% obtained at conditions of 50 g/L and 7.0% NaOH. Degradation of cellulose, hemicellulose and lignin after treatment increased by 4.0-9.0%, 3.3-6.2%, and 11.1-20.5%, respectively, with NaOH dose ranged from 3.0% to 7.0%. Scanning electron microscopy (SEM), FTIR spectra and Crystallinity measurements showed that the lignocellulosic structures were disrupted by NaOH. The results indicate poplar processing residues might be an efficient substrate for methane production after alkaline treatment.

  20. Assessment of the effect of quality factors on the assortment structure in poplar plantations

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2008-01-01

    Full Text Available Quality factors affecting the assortment quality structure in poplar plantations were researched on nine temporary sample plots in the period 1997-2004, from the aspect of the implementation of roundwood standards. Sample plots were selected depending on the factors, the effect of which was studied. The following factors were researched: clonal species, planting pattern, flood risk, pruning of branches, plantation position and age. The study was performed by the original methodology. Based on the study results, it is concluded that knots have the highest effect on the assortment quality structure in poplar plantations, regardless of the site and stand conditions. Their effect rises significantly with the increase of tree diameter. Also, the analyses show that the number of large and rotten knots on the tree trunk increases considerably with the older age. In the flooded area, the sweep of the lower part of the stem is more intensive and multiple curvatures are frequent on the trees growing immediately along the river, whereas curvature decreases with the distance from the river bank. Based on the study results, it is concluded that the percentage of best quality assortments is considerably reduced by the above wood defects.

  1. Non-destructive Analysis Chlorophyll Content of Different Genotypes of Poplars Based on Hyperspectral Reflectance Data

    Science.gov (United States)

    Jin, S.; Dian, Y.; Wang, R.; Peng, L.; Liu, X.; Zhou, Z.; Zhong, S.; Wang, Y.

    2016-11-01

    Leaf Chlorophyll content (Ct) indicates plant physiological status and can be detected by hyperspectral measurements. However, it is difficult to conclude that different genotypes of same species have the same relationship with the hyperspectral data. The aim of this paper was to test that whether the different genotypes of same species have the similar relationship with hyperspectral reflectance. First of all, spectral reflectance of populus simonii (Populus simonii Carr) and I-72 poplar (Populus euramericana cv. ‘San Martino I-72/58’) were collected by spectrometric meter, and then extract chlorophyll index (CI) and other 11 types of vegetation indices from the hyperspectral reflectance data. At last, relationships between different vegetation indices and Ct of the two genotypes of poplar were compared. Results show that (1) the relationships between SPAD value and Ct are different in the low and high Ct level, we can choose proper vegetation index, REPIG, mSR705 and SDr/SDb et al to predict the Ct value. (2) Meanwhile, we can use PSSRb and PRI to distinguish fine difference between different genotypes.

  2. Research on Poplar Leaf Rust%杨树叶锈病研究

    Institute of Scientific and Technical Information of China (English)

    肖婷; 邝海菊; 何香; 兰晓君; 艾尔肯·热合曼; 古丽斯玛依·艾拜都拉

    2009-01-01

    Leaf rust caused by Melampsora larici-populina was the most widespread and serious disease of poplars,led to timber volume loss and wood quality reduction,and badly restricted the development of commodity and ecology forest.Researching on Melampsora larici-populina was introduced in this paper from aspects of distribution and host varieties of plant pathogenic fungi,physiological differentiation,host poplar resistance and molecular markers,control measures and so on.%松杨栅锈菌(Melampsora larici-populina)导致的杨树叶锈病是杨树病害中分布最广、危害最大的一种病害,它造成杨树林的材积损失和材质下降,严重制约着杨树商品林和生态林的发展.该文从病原菌的分布和寄主种类、病原菌生理分化、寄主抗锈性及分子标记、防治措施等几方面介绍了杨树叶锈病的研究.

  3. Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees.

    Science.gov (United States)

    Algreen, Mette; Trapp, Stefan; Rein, Arno

    2014-01-01

    The main purpose of this study was to determine typical concentrations of heavy metals (HM) in wood from willows and poplars, in order to test the feasibility of phytoscreening and phytoextraction of HM. Samples were taken from one strongly, one moderately, and one slightly polluted site and from three reference sites. Wood from both tree species had similar background concentrations at 0.5 mg kg(-1) for cadmium (Cd), 1.6 mg kg(-1) for copper (Cu), 0.3 mg kg(-1) for nickel (Ni), and 25 mg kg(-1) for zinc (Zn). Concentrations of chromium (Cr) and lead (Pb) were below or close to detection limit. Concentrations in wood from the highly polluted site were significantly elevated, compared to references, in particular for willow. The conclusion from these results is that tree coring could be used successfully to identify strongly heavy metal-polluted soil for Cd, Cu, Ni, Zn, and that willow trees were superior to poplars, except when screening for Ni. Phytoextraction of HMs was quantified from measured concentration in wood at the most polluted site. Extraction efficiencies were best for willows and Cd, but below 0.5% over 10 years, and below 1‰ in 10 years for all other HMs.

  4. Variation of microfibril angle and its correlation to wood properties in poplars

    Institute of Scientific and Technical Information of China (English)

    FANGSheng-zuo; YANGWen-zhong; FUXiang-xiang

    2004-01-01

    The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle,wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8°to 28° between growth rings with cambial age and showed a consistent pith-to-bark trend of decline angles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (α=0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.

  5. Interclonal and within-tree variation in wood properties of poplar clones

    Institute of Scientific and Technical Information of China (English)

    FANGSheng-zuo; YANGWen-zhong

    2003-01-01

    The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively,for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.

  6. Immunolocalization of phenylalanine ammonia-lyase and cinnamate-4-hydroxylase in differentiating xylem of poplar.

    Science.gov (United States)

    Sato, Takahiko; Takabe, Keiji; Fujita, Minoru

    2004-01-01

    Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) and cinnamate-4-hydroxylase (C4H; EC 1.14.13.11) are pivotal enzymes involved in lignification. We synthesized peptides as the epitopes according to the amino acid sequences of these enzymes, coupled them with hemocyanin, and injected them into mice. The antiserums against peptides of PAL and C4H specifically detected PAL and C4H in the crude enzymes extracted from differentiating xylem of poplar, respectively. PAL and C4H were localized in differentiating xylem of poplar. PAL labeling was mainly localized in the cytosol, and somewhat localized on the rough-endoplasmic reticulum (r-ER) and the Golgi apparatus. In contrast, C4H was mainly observed on r-ER and the Golgi apparatus. These findings suggest that conversion of phenylalanine to cinnamic acid occurs in the cytosol and the following reaction occurs near the membrane of r-ER and the Golgi apparatus. The possibility of coordinated localization of PAL and C4H is discussed.

  7. The impact of calculation on the value of thermodynamic parameters of copper adsorption on poplar sawdust

    Directory of Open Access Journals (Sweden)

    Brdar Mirjana M.

    2011-01-01

    Full Text Available The adsorption of Cu(II onto poplar sawdust as an adsorbent is analyzed. The experimental data were fitted by the Langmuir isotherm using four linearized forms at the isotherm along with the original one. The least squares regression method was applied. Using the obtained Langmuir constants by each at methods, the enthalpy, entropy and Gibbs free energy at adsoption were calculated. A comparison of the used linear and non-linear regression methods in view at the goodness of the fit is presented. The coefficient of correlation was adopted as a criterionn to select the best method. The impact of the choice at regression model on the resulting estimates of the thermodynamic parameters is discussed. The best fit of the experimental data is obtained by the nonlinear regression. Thus, it is recommended to use the Langmuir parameters calculated by the nonlinear regression for estimating the thermodynamic parameters of adsorptin. The differences in the values obtained by different models are not so large to change the basic conclusion that the adsorption of copper ions on poplar sawdust is a spontaneous endothermic process i.e. that tested adsorbent has an affinity for copper ions.

  8. The Oak Ridge Y-12 Plant biological monitoring and abatement program for East Fork Poplar Creek

    Energy Technology Data Exchange (ETDEWEB)

    Loar, J.M.; Adams, S.M.; Allison, L.J.; Giddings, J.M.; McCarthy, J.F.; Southworth, G.R.; Smith, J.G.; Stewart, A.J. (Oak Ridge National Lab., TN (USA); Springborn Bionomics, Inc., Wareham, MA (USA); Oak Ridge National Lab., TN (USA))

    1989-10-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Y-12 Plant, a nuclear weapons components production facility located in Oak Ridge, Tennessee, and operated by Martin Marietta Energy Systems, Inc., for the US Department of Energy. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Oak Ridge Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek), in particular, the growth and propagation of fish and aquatic life, as designated by the Tennessee Department of Health and Environment. A second purpose for the BMAP is to document the ecological effects resulting from implementation of a water pollution control program that will include construction of nine new wastewater treatment facilities over the next 4 years. Because of the complex nature of the effluent discharged to East Fork Poplar Creek and the temporal and spatial variability in the composition of the effluent (i.e., temporal variability related to various pollution abatement measures that will be implemented over the next several years and spatial variability caused by pollutant inputs downstream of the Oak Ridge Y-12 Plant), a comprehensive, integrated approach to biological monitoring was developed for the BMAP. 39 refs., 5 figs., 8 tabs.

  9. Patterns of genomic variation in the poplar rust fungus Melampsora larici-populina identify pathogenesis-related factors

    Directory of Open Access Journals (Sweden)

    Antoine ePersoons

    2014-09-01

    Full Text Available Melampsora larici-populina is a fungal pathogen responsible for foliar rust disease on poplar trees, which causes damage to forest plantations worldwide, particularly in Northern Europe. The reference genome of the isolate 98AG31 was previously sequenced using a whole genome shotgun strategy, revealing a large genome of 101 megabases containing 16,399 predicted genes, which included secreted protein genes representing poplar rust candidate effectors. In the present study, the genomes of 15 isolates collected over the past 20 years throughout the French territory, representing distinct virulence profiles, were characterized by massively parallel sequencing to assess genetic variation in the poplar rust fungus. Comparison to the reference genome revealed striking structural variations. Analysis of coverage and sequencing depth identified large missing regions between isolates related to the mating type loci. More than 611,824 single-nucleotide polymorphism (SNP positions were uncovered overall, indicating a remarkable level of polymorphism. Based on the accumulation of non-synonymous substitutions in coding sequences and the relative frequencies of synonymous and non-synonymous polymorphisms (i.e. PN/PS, we identify candidate genes that may be involved in fungal pathogenesis. Correlation between non-synonymous SNPs in genes encoding secreted proteins and pathotypes of the studied isolates revealed candidate genes potentially related to virulences 1, 6 and 8 of the poplar rust fungus.

  10. Free-air CO2 enrichment (FACE) enhances biomass production in a short-rotation poplar plantation

    NARCIS (Netherlands)

    Calfapietra, C.; Gielen, B.; Galema, A.N.J.; Lukac, M.; Angelis, de P.; Moscatelli, M.C.; Ceulemans, R.; Scarascia-Mugnozza, G.

    2003-01-01

    This paper investigates the possible contribution of Short Rotation Cultures (SRC) to carbon sequestration in both current and elevated atmospheric CO2 concentrations ([CO2]). A dense poplar plantation (1 x 1 m) was exposed to a [CO2] of 550 ppm in Central Italy using the free-air CO2 enrichment (FA

  11. Plasmodesmatal Dynamics in Both Woody Poplar and Herbaceous Winter Wheat Under Controlled Short Day and in Field Winter Period

    Institute of Scientific and Technical Information of China (English)

    JIANLing-Cheng; WANGHong

    2004-01-01

    Electron microscopic observation revealed that poplar (Populus deltoides Marsh.) and winterwheat ( Triticum aestivum L. cv. Seward 80004) plasmodesmatal structures significantly changed undershort day (SD, 8 h light) and in winter period, and such changes differed also noticeably between these twowoody and herbaceous plants. Under long day (LD, 16 h light), many plasmodesmata with strong stainappeared in the cell wall of both poplar apical buds and winter wheat young leaf tissues, and connections ofcytoplasmic endoplasmic reticulum (ER) with the ER in some plasmodesmata were observed. In addition,the typical “neck type” plasmodesmata were observed in winter wheat young leaf tissues, and their centraldesmotubules (appressed-ER) could be clearly identified. Under SD, many poplar plasmodesmata showedonly a partial structure in the cell wall and appeared to be discontinued; some plasmodesmata swelled in themid-wall, forming the cavity, and no appressed-ER appeared, in winter wheat, however, no noticeablealterations of plasmodesmata occurred, and the plasmodesmatal structure essentially remained the sameas it was under LD. In winter period, poplar plasmodesmata had a similar morphology as those observedunder SD, however, winter wheat manifested at least two types of significant plasmodesmatal alterations:one plugged by electron-dense materials and the other of reduced neck region compared to those underLD. The above dynamic difference of the two species plasmodesmata under SD and winter period revealedthe difference of their dormancy development under those environmental conditions.

  12. Comparing Soil Carbon of Short Rotation Poplar Plantations with Agricultural Crops and Woodlots in North Central United States

    Science.gov (United States)

    Mark D. Coleman; J.G. Isebrands; David N. Tolsted; Virginia R. Tolbert

    2004-01-01

    We collected soil samples from 27 study sites across North Central United States to compare the soil carbon of short rotation poplar plantations to adjacent agricultural crops and woodlots. Soil organic carbon (SOC) ranged from 20 to more than 160 Mg/ha across the sampled sites. Lowest SOC levels were found in uplands and highest levels in riparian soils. We attributed...

  13. Using a combined hydrolysis factor to optimize high titer ethanol production from sulfite-pretreated poplar without detoxification

    Science.gov (United States)

    Jingzhi Zhang; Feng Gu; J.Y. Zhu; Ronald S. Zalesny Jr.

    2015-01-01

    Sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL) was applied to poplar NE222 chips in a range of chemical loadings, temperatures, and times. The combined hydrolysis factor (CHF) as a pretreatment severity accurately predicted xylan dissolution by SPORL. Good correlations between CHF and pretreated...

  14. A Valuable Biochar from Poplar Catkins with High Adsorption Capacity for Both Organic Pollutants and Inorganic Heavy Metal Ions.

    Science.gov (United States)

    Liu, Xia; Sun, Ju; Duan, Shengxia; Wang, Yanan; Hayat, Tasawar; Alsaedi, Ahmed; Wang, Chengming; Li, Jiaxing

    2017-08-30

    In this paper, biochar derived from poplar catkins was used as an economical and renewable adsorbent for adsorption organic and inorganic pollutants such as, dyes, organic compounds, and heavy metal ions from wastewater. Mesoporous activated carbonized poplar catkins (ACPCs) were produced from char as a by-product by carbonized poplar catkins (CPCs). With their high surface area, ACPCs exhibited the maximum adsorption capacities of 71.85 and 110.17 mg/g for the removal of inorganic U(VI) and Co(II). Compared other biochars adsorbents, ACPCs can also adsorb organic pollutants with the maximum adsorption capacities of 534, 154, 350, 148 and 384 mg/g for methylene blue (MB), methyl orange (MO), Congo red (CR), chloramphenicol (CAP) and naphthalene. The adsorption of organic pollutants was fitted with pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models figure out the kinetic parameters and adsorption mechanisms. Langmuir adsorption isotherm was found to be suitable for Co(II) and U(VI) adsorption and thermodynamic studies indicated adsorption processes to be endothermic and spontaneous. The adsorption process includes both outer-sphere surface complexes and hydrogen-bonding interactions. The results showed that biochar derived from poplar catkins was a potential material to remove pollutants in wastewater.

  15. Free-air CO2 enrichment (FACE) enhances biomass production in a short-rotation poplar plantation

    NARCIS (Netherlands)

    Calfapietra, C.; Gielen, B.; Galema, A.N.J.; Lukac, M.; Angelis, de P.; Moscatelli, M.C.; Ceulemans, R.; Scarascia-Mugnozza, G.

    2003-01-01

    This paper investigates the possible contribution of Short Rotation Cultures (SRC) to carbon sequestration in both current and elevated atmospheric CO2 concentrations ([CO2]). A dense poplar plantation (1 x 1 m) was exposed to a [CO2] of 550 ppm in Central Italy using the free-air CO2 enrichment (FA

  16. Impact of poplar-based phytomanagement on soil properties and microbial communities in a metal-contaminated site.

    Science.gov (United States)

    Foulon, Julie; Zappelini, Cyril; Durand, Alexis; Valot, Benoit; Blaudez, Damien; Chalot, Michel

    2016-10-01

    Despite a long history of use in phytomanagement strategies, the impacts of poplar trees on the structure and function of microbial communities that live in the soil remain largely unknown. The current study combined fungal and bacterial community analyses from different management regimes using Illumina-based sequencing with soil analysis. The poplar phytomanagement regimes led to a significant increase in soil fertility and a decreased bioavailability of Zn and Cd, in concert with changes in the microbial communities. The most notable changes in the relative abundance of taxa and operational taxonomic units unsurprisingly indicated that root and soil constitute distinct ecological microbial habitats, as exemplified by the dominance of Laccaria in root samples. The poplar cultivar was also an important driver, explaining 12% and 6% of the variance in the fungal and bacterial data sets, respectively. The overall dominance of saprophytic fungi, e.g. Penicillium canescens, might be related to the decomposition activities needed at the experimental site. Our data further highlighted that the mycorrhizal colonization of poplar cultivars varies greatly between the species and genotypes, which is exemplified by the dominance of Scleroderma under Vesten samples. Further interactions between fungal and bacterial functional groups stressed the potential of high-throughput sequencing technologies in uncovering the microbial ecology of disturbed environments. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Increased nitrogen use efficiency of a short-rotation poplar plantation is increased under elevated CO2

    NARCIS (Netherlands)

    Calfapietra, C.; Angelis, de P.; Gielen, B.; Lukac, M.; Moscatelli, M.C.; Avino, G.; Lagomarsino, A.; Polle, A.; Ceulemans, R.; Mugnozza, G.S.; Hoosbeek, M.R.; Cotrufo, M.F.

    2007-01-01

    We estimated nitrogen (N) use by trees of three poplar species exposed for 3 years to free air CO2 enrichment (FACE) and determined whether the CO2 treatment affected the future N availability of the plantation. Trees were harvested at the end of the first 3-year rotation and N concentration and con

  18. [Seasonal dynamics of quantitative and morphological traits of poplar fine roots and their differences between successive rotation plantations].

    Science.gov (United States)

    Wang, Yan-ping; Xu, Tan; Zhu, Wan-rui; Wang, Qi-tong; Liu, Meng-ling; Wang, Hua-tian; Li, Chuan-rong; Dong, Yu-feng

    2016-02-01

    Based on the fine root samples of the first and second generations of poplar (Populus x euramericana ' Neva'), this study examined the response of quantitative and morphological traits of fine roots of different orders and the difference between generations. The results showed that, the quantitative traits of fine roots, such as root length, root surface area and root biomass, presented obvious seasonal variation, and the fine root traits had obvious difference among root orders. The quantitative traits of lower-order fine roots showed significant seasonal difference, and the fine root biomass increased in the growing season and then decreased significantly. The specific root length (SRL) of higher-order roots also showed significant change with season, while the root length density (RLD) and root tissue density (RTD) changed a little. The successive rotation resulted in the significant increase of root length, root biomass, SRL and RLD of 1-2 orders in the growing season. The quantitative traits of first order root significantly positively correlated with soil temperature and moisture, and significantly negatively correlated with the soil organic matter and soil available nitrogen content. However, the quantitative traits of second order root only showed significant correlation with soil nutrient content. The seasonal dynamics of poplar fine roots and the difference between successive rotation plantations implied carbon investment change of poplar to roots. Soil nutrient deficiency induced more carbon investment into roots, and this carbon allocation pattern might affect the aboveground productivity of poplar plantation.

  19. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  20. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  1. Implications of climate change for evaporation from bare soils in a Mediterranean environment.

    Science.gov (United States)

    Aydin, Mehmet; Yano, Tomohisa; Evrendilek, Fatih; Uygur, Veli

    2008-05-01

    The purpose of this study was to predict quantitative changes in evaporation from bare soils in the Mediterranean climate region of Turkey in response to the projections of a regional climate model developed in Japan (hereafter RCM). Daily RCM data for the estimation of reference evapotranspiration (ETr) and soil evaporation were obtained for the periods of 1994--2003 and 2070--2079. Potential evaporation (Ep) from bare soils was calculated using the Penman-Monteith equation with a surface resistance of zero. Simulation of actual soil evaporation (Ea) was carried out using Aydin model (Aydin et al., Ecological Modelling 182:91-105, 2005) combined with Aydin and Uygur (2006, A model for estimating soil water potential of bare fields. In Proceedings of the 18th International Soil Meeting (ISM) on Soils Sustaining Life on Earth, Managing Soil and Technology, Sanliurfa, 477-480pp.) model of predicting soil water potential at the top surface layer of a bare soil, after performances of Aydin model (R2 = 94.0%) and Aydin and Uygur model (R2 = 97.6) were tested. The latter model is based on the relations among potential soil evaporation, hydraulic diffusivity, and soil wetness, with some simplified assumptions. Input parameters of the model are simple and easily obtainable such as climatic parameters used to compute the potential soil evaporation, average diffusivity for the drying soil, and volumetric water content at field capacity. The combination of Aydin and Aydin and Uygur models appeared to be useful in estimating water potential of soils and Ea from bare soils, with only a few parameters. Unlike ETr and Ep projected to increase by 92 and 69 mm (equivalent to 8.0 and 7.3% increases) due to the elevated evaporative demand of the atmosphere, respectively, Ea from bare soils is projected to reduce by 50 mm (equivalent to a 16.5% decrease) in response to a decrease in rainfall by 46% in the Mediterranean region of Turkey by the 2070s predicted by RCM, and consequently

  2. Effects of root pruning on the growth and rhizosphere soil characteristics of short-rotation closed-canopy poplar

    Energy Technology Data Exchange (ETDEWEB)

    Du, Z. Y.; Xing, S. J.; Ma, B. Y.; Liu, F. C.; Ma, H. L.; Wang, Q. H.

    2012-11-01

    When poplar trees planted at a high density are canopy-closed in plantation after 4-5 years of growth, the roots of adjacent trees will inevitably intermingle together, which possibly restricts the nutrient uptake by root system. Root pruning might stimulate the emergence of fine roots and benefit the tree growth of short-rotation poplar at the stage of canopy closing. The aim of this study is to evaluate the effects of root pruning on DBH (diameter at breast height, 1.3 m), tree height, nutrients (N, P and K) and hormones (indoleacetic acid and cytokinin) in poplar leaves, gas exchange variables (photosynthetic rate and stomatal conductance), and rhizosphere soil characteristics. Field experiment was carried out with four-yearold poplar (Populus × euramericana cv. ‘Neva’) planted in a fluvo-aquic loam soil in Shandong province, China in early April, 2008. Three root pruning treatments (severe, moderate and light degree) were conducted at the distances of 6, 8 and 10 times DBH on both inter-row sides of the trees to the depth of 30 cm, respectively. The results showed that the growth performance was obtained in the following order of treatments: moderate > light = control > severe. In the rhizophere soil, moderate and light pruning increased the microbial populations, enzymatic activities, and the concentrations of available N, P, K and organic matter. Generally, root pruning to improve tree growth and rhizosphere soil fertility can be recommended in canopy-closed poplar plantation. The appropriate selection of root pruning intensity is a pivotal factor for the effectiveness of this technique. (Author) 35 refs.

  3. Sub-pixel estimation of tree cover and bare surface densities using regression tree analysis

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Zangrando Toneli

    2011-09-01

    Full Text Available Sub-pixel analysis is capable of generating continuous fields, which represent the spatial variability of certain thematic classes. The aim of this work was to develop numerical models to represent the variability of tree cover and bare surfaces within the study area. This research was conducted in the riparian buffer within a watershed of the São Francisco River in the North of Minas Gerais, Brazil. IKONOS and Landsat TM imagery were used with the GUIDE algorithm to construct the models. The results were two index images derived with regression trees for the entire study area, one representing tree cover and the other representing bare surface. The use of non-parametric and non-linear regression tree models presented satisfactory results to characterize wetland, deciduous and savanna patterns of forest formation.

  4. Proposal to observe half-bare electrons on a 45-MeV linac

    Science.gov (United States)

    Trofymenko, S. V.; Shul'ga, N. F.; Delerue, N.; Jenzer, S.; Khodnevych, V.; Migayron, A.

    2017-07-01

    The experimental investigation of the transition radiation (TR) generated by a “half-bare” electron having the proper field different from the Coulomb one is proposed. The electrons in half-bare state are intended to be obtained in the result of their crossing of a conducting screen. We propose to investigate the influence of the half-bare state of electron in this process upon TR generated by such electron on a downstream OTR screen situated on some distance along the direction of the electron beam from the upstream screen which “undresses” the particle. Calculations are presented for the case of a 45 MeV linac and the distance between the screens in the region between 100 mm and 300 mm. The proposed experiment is expected to reveal new features of TR signal in such process comparing to previous measurements.

  5. Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sasscer, D.S.; Ernst, R.; Morgan, T.O.; Rivera, C.; Scott, A.C.; Summerson, T.J.

    1984-01-01

    In a cooperative research effort between The Puerto Rico Center of Energy and Environment Research, Kaiser Aluminum and Chemical Corporation and The Trane Company, a six month study was made of the seawater corrosion performance of various aluminum materials to test their suitability for use in seawater heat exchangers. The materials tested included bare 3004 tubes, 7072 Alclad 3004 tubes and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger extrusions from a brazed aluminium, plate-fin heat exchanger developed by The Trane Company. The test materials were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr).

  6. Effects of lidar point density on bare earth extraction and DEM creation

    Science.gov (United States)

    Puetz, Angela M.; Olsen, R. Chris; Anderson, Brian

    2009-05-01

    Data density has a crucial impact on the accuracy of Digital Elevation Models (DEMs). In this study, DEMs were created from a high point-density LIDAR dataset using the bare earth extraction module in Quick Terrain Modeler. Lower point-density LIDAR collects were simulated by randomly selecting points from the original dataset at a series of decreasing percentages. The DEMs created from the lower resolution datasets are compared to the original DEM. Results show a decrease in DEM accuracy as the resolution of the LIDAR dataset is reduced. Some analysis is made of the types of errors encountered in the lower resolution DEMs. It is also noted that the percentage of points classified as bare earth decreases as the resolution of the LIDAR dataset is reduced.

  7. Long-term continuous atmospheric CO2 measurements at Baring Head, New Zealand

    Directory of Open Access Journals (Sweden)

    S. E. Nichol

    2012-12-01

    Full Text Available We present descriptions of the in situ instrumentation, calibration procedures, intercomparison efforts, and data filtering methods used in a 39-yr record of continuous atmospheric carbon dioxide (CO2 observations made at Baring Head, New Zealand. Located on the southern coast of the North Island, Baring Head is exposed to extended periods of strong air flow from the south with minimal terrestrial influence resulting in low CO2 variability. The site is therefore well suited for sampling air masses that are representative of the Southern Ocean region. Instrumental precision is better than 0.015 ppm (1-σ on 1-Hz values. Comparisons to over 600 co-located flask samples, as well as laboratory based flask and cylinder comparison exercises, suggest that over recent decades compatibility with respect to the Scripps Institution of Oceanography (SIO and World Meteorological Organisation (WMO CO2 scales has been 0.3 ppm or better.

  8. Quantifying and isolating stable soil organic carbon using long-term bare fallow experiment

    DEFF Research Database (Denmark)

    Barré, P; Eglin, T; Christensen, Bent Tolstrup;

    2010-01-01

    The stability of soil organic matter (SOM) is a major source of uncertainty in predicting atmospheric CO2 concentration during the 21st century. Isolating the stable soil carbon (C) from other, more labile, C fractions in soil is of prime importance for calibrating soil C simulation models......, and gaining insights into the mechanisms that lead to soil C stability. Long-term experiments with continuous bare fallow (vegetation-free) treatments in which the decay of soil C is monitored for decades after all inputs of C have stopped, provide a unique opportunity to assess the quantity of stable soil C....... We analyzed data from six bare fallow experiments of long-duration (>30 yrs), covering a range of soil types and climate conditions, and sited at Askov (Denmark), Grignon and Versailles (France), Kursk (Russia), Rothamsted (UK), and Ultuna (Sweden). A conceptual three pool model dividing soil C...

  9. A comparison of various lignin-extraction methods to enhance the accessibility and ease of enzymatic hydrolysis of the cellulosic component of steam-pretreated poplar

    National Research Council Canada - National Science Library

    Dong Tian; Richard P Chandra; Jin-Suk Lee; Canhui Lu; Jack N Saddler

    2017-01-01

    ...% of the hemicellulose from poplar while limiting the acid-catalysed condensation of lignin. This potentially allowed for subsequent lignin extraction using various lignin solvents to produce a more accessible cellulosic substrate...

  10. Transportable Waste-to-Energy System (TWES) Energy Recovery From Bare Base Waste

    Science.gov (United States)

    2008-02-01

    removed and/or partially burned. Instead the furnace, coupled with a shredder , will completely burn the waste and provide heat for water or other...Photos from Ali Al Salem, AF bare base Nov 1998, FOUO-for official use only 8 8 TWES Fuel Processing Bulk Trash Shredder Shredded Fuel TWES Furnace...Program (FEMP) to initiate the conversion. • Will install and test electricity production at Tyndall AFB 15 15 TWES Process Diagram Shredders Useful

  11. Optical coupling of bare optoelectronic components and flexographically printed polymer waveguides in planar optronic systems

    Science.gov (United States)

    Wang, Yixiao; Wolfer, Tim; Lange, Alex; Overmeyer, Ludger

    2016-05-01

    Large scale, planar optronic systems allowing spatially distributed functionalities can be well used in diverse sensor networks, such as for monitoring the environment by measuring various physical quantities in medicine or aeronautics. In these systems, mechanically flexible and optically transparent polymeric foils, e.g. polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET), are employed as carrier materials. A benefit of using these materials is their low cost. The optical interconnections from light sources to light transmission structures in planar optronic systems occupy a pivotal position for the sensing functions. As light sources, we employ the optoelectronic components, such as edgeemitting laser diodes, in form of bare chips, since their extremely small structures facilitate a high integration compactness and ensure sufficient system flexibility. Flexographically printed polymer optical waveguides are deployed as light guiding structures for short-distance communication in planar optronic systems. Printing processes are utilized for this generation of waveguides to achieve a cost-efficient large scale and high-throughput production. In order to attain a high-functional optronic system for sensing applications, one of the most essential prerequisites is the high coupling efficiency between the light sources and the waveguides. Therefore, in this work, we focus on the multimode polymer waveguide with a parabolic cross-section and investigate its optical coupling with the bare laser diode. We establish the geometrical model of the alignment based on the previous works on the optodic bonding of bare laser diodes and the fabrication process of polymer waveguides with consideration of various parameters, such as the beam profile of the laser diode, the employed polymer properties of the waveguides as well as the carrier substrates etc. Accordingly, the optical coupling of the bare laser diodes and the polymer waveguides was simulated

  12. Bare-State Time-Evolving Operator Solution to Raman Model in A Configuration

    Institute of Scientific and Technical Information of China (English)

    WUYing; NIEYi-Zhen; YANGXiao-Xue

    2003-01-01

    We derive exact analytical expressions of time-evolving bare-state operators of level occupation numbers and the photon numbers for a composite system consisting of a three-level atom interacting with two modes ofa quantized electromagnetic field in A configuration. These results demonstrate the oscillations with three-family frequencies for a nonzero detuning, which dramatically differ from the previous results showing only single-family Rabi oscillations.

  13. Bare-State Time-Evolving Operator Solution to Raman Model in A Configuration

    Institute of Scientific and Technical Information of China (English)

    WU Ying; NIE Yi-Zhen; YANG Xiao-Xue

    2003-01-01

    We derive exact analytical expressions of time-evolving bare-state operators of level occupation numbers and the photon numbers for a composite system consisting of a three-level atom interacting with two modes of a quantized electromagnetic field in A configuration. These results demonstrate the oscillations with three-family frequencies for a nonzero detuning, which dramatically differ from the previous results showing only single-family Rabi oscillations.

  14. Towards new methodology for improvement of topographic and anisotropic correction of desert bare soil

    Science.gov (United States)

    Alomran, Ali

    Desert bare soil has been found in literature to exhibit anisotropic reflectance behaviour. Anisotropy is described by Bidirectional Reflectance Distribution function (BRDF). Literature studies have limited their investigations to the behaviour of the topographic corrections of Minnaert and C models (simple forms of the empirical type of BRDF) with terrain variables (slope and orientation). Yet, none of these studies, especially for desert bare soil, has investigated the behaviour of the coefficient values of Minnaert and C with terrain variables. The investigation in this study has revealed that the relation between terrain slope (derived from both DEM level-1 and level-2) of desert bare soil in Saudi Arabia and K and C values follow closely a 2nd order polynomial trend. K curves have taken convex shapes, whereas C curves were concave. The Minnaert (K) and C coefficients trends have shown that surface Lambertian behaviour is more pronounced on slopes facing away from the sun than on sun facing slopes. Unlike the Minnaert K and C coefficients derived from four spectral classes, this author's newly developed terrain slope, aspect and phase angle dependant's C and Minnaert coefficients produced promising results compared to the global K and C. Induced BRDF effects in the desert bare soil is found the more probable dominating cause for the scatter/jitter in the radiance/cos(i) regression plots that remained after radiometric correction. Though its high topographic correction efficiency and unlike Minnaert model, C model tends to maintain the uncorrected radiance values unchanged after correction (i.e. not amplified to compensate for low sun angle).

  15. Bare below elbows: does this policy affect handwashing efficacy and reduce bacterial colonisation?

    Science.gov (United States)

    Burger, A; Wijewardena, C; Clayson, S; Greatorex, R A

    2011-01-01

    UK Department of Health guidelines recommend that clinical staff are 'bare below the elbows'. There is a paucity of evidence to support this policy. One may hypothesise that absence of clothing around wrists facilitates more effective handwashing: this study aims to establish whether dress code affects bacterial colonisation before and after handwashing. Sixty-six clinical staff volunteered to take part in the study, noting whether they were bare below the elbows (BBE) or not bare (NB). Using a standardised technique, imprints of left and right fingers, palms, wrists and forearms were taken onto mini agar plates. Imprints were repeated after handwashing. After incubation, colonies per plate were counted, and subcultures taken. Thirty-eight staff were BBE and 28 were not. A total of 1112 plates were cultured. Before handwashing there was no significant difference in number of colonies between BBE and NB groups (Mann-Whitney, P < 0.05). Handwashing reduced the colony count, with greatest effect on fingers, palms and dominant wrists (t-test, P < 0.05). Comparing the two groups again after handwashing revealed no significant difference (Mann-Whitney, P < 0.05). Subcultures revealed predominantly skin flora. There was a large variation in number of colonies cultured. Handwashing resulted in a statistically significant reduction in colony count on fingers, palms and dominant wrist regardless of clothing. We conclude that handwashing produces a significant reduction in number of bacterial colonies on staff hands, and that clothing that is not BBE does not impede this reduction.

  16. Percutaneous Creation of Bare Intervascular Tunnels for Salvage of Thrombosed Hemodialysis Fistulas Without Recanalizable Outflow

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Matt Chiung-Yu, E-mail: jjychen@gmail.com [Yuan’s General Hospital, Department of Interventional Radiology (China); Wang, Yen-Chi [E-Da Hospital, Department of Radiology (China); Weng, Mei-Jui [Kaohsiung Veterans General Hospital, Department of Radiology (China)

    2015-08-15

    PurposeThis study aimed to retrospectively assess the efficacy of a bare intervascular tunnel for salvage of a thrombosed hemodialysis fistula. We examined the clinical outcomes and provided follow-up images of the bare intervascular tunnel.Materials and MethodsEight thrombosed fistulas lacked available recanalizable outflow veins were included in this study. These fistulas were salvaged by re-directing access site flow to a new outflow vein through a percutaneously created intervascular tunnel without stent graft placement. The post-intervention primary and secondary access patency rates were calculated using the Kaplan–Meier method.ResultsThe procedural and clinical success rates were 100 %. Post-intervention primary and secondary access patency at 300 days were 18.7 ± 15.8 and 87.5 ± 11.7 %, respectively. The mean follow-up period was 218.7 days (range 10–368 days). One patient died of acute myocardial infarction 10 days after the procedure. No other major complications were observed. Minor complications, such as swelling, ecchymosis, and pain around the tunnel, occurred in all of the patients.ConclusionsPercutaneous creation of a bare intervascular tunnel is a treatment option for thrombosed hemodialysis fistulas without recanalizable outflow in selected patients.

  17. Clinical utility of platinum chromium bare-metal stents in coronary heart disease

    Directory of Open Access Journals (Sweden)

    Jorge C

    2015-08-01

    Full Text Available Claudia Jorge,1 Christophe Dubois1,2 1Department of Cardiovascular Medicine, University Hospitals Leuven, 2Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium Abstract: Coronary stents represent a key development for the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. While drug-eluting stents gained wide acceptance in contemporary percutaneous coronary intervention practice, further developments in bare-metal stents remain crucial for patients who are not candidates for drug-eluting stents, or to improve metallic platforms for drug elution. Initially, stent platforms used biologically inert stainless steel, restricting stent performance due to limitations in flexibility and strut thickness. Later, cobalt chromium stent alloys outperformed steel as the material of choice for stents, allowing latest generation stents to be designed with significantly thinner struts, while maintaining corrosion resistance and radial strength. Most recently, the introduction of the platinum chromium alloy refined stent architecture with thin struts, high radial strength, conformability, and improved radiopacity. This review will provide an overview of the novel platinum chromium bare-metal stent platforms available for coronary intervention. Mechanical properties, clinical utility, and device limitations will be summarized and put into perspective. Keywords: bare metal stent, coronary stent alloys, coronary artery disease

  18. Charge-exchange cross sections and beam lifetimes for stored and decelerated bare uranium ions

    Energy Technology Data Exchange (ETDEWEB)

    Stoehlker, T. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Ludziejewski, T.; Reich, H.; Bosch, F.; Franzke, B.; Kozhuharov, C.; Menzel, G.; Mokler, P.H.; Nolden, F.; Steck, M. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik; Dunford, R.W. [Argonne National Lab., IL (United States). Physics Div.; Eichler, J. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Theoretische Physik]|[Freie Univ. Berlin (Germany). Fachbereich Physik; Rymuza, P. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland); Stachura, Z. [Institute of Nuclear Physics, Cracow (Poland); Swiat, P.; Warczak, A. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki; Winkler, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)

    1998-08-01

    Charge-exchange cross sections and beam lifetimes are studied for decelerated bare uranium ions at the ESR storage ring. By deceleration from the initial energy of 358 MeV/u down to various energies as low as 49 MeV/u, i.e. far below the production energy of bare ionic species, the electron pick-up cross sections were obtained for collisions with N{sub 2}, Ar, CH{sub 4} and Kr gaseous targets. The measured cross sections and beam lifetimes are compared with the theoretical results for radiative and non-radiative electron capture. The present data along with the theoretical approximations discussed, provide a solid basis for the estimation of beam lifetimes for decelerated bare high-Z ions. Moreover, a normalization procedure is proposed, in which absolute total charge-exchange cross sections are derived by normalizing the simultaneously measured yield of K-REC photons to rigorously calculated relativistic cross sections. This method along with the unprecedented beam conditions at the ESR storage ring, allows a significant improvement in the accuracy of cross section data. (orig.)

  19. Patches of bare ground as a staple commodity for declining ground-foraging insectivorous farmland birds.

    Directory of Open Access Journals (Sweden)

    Michael Schaub

    Full Text Available Conceived to combat widescale biodiversity erosion in farmland, agri-environment schemes have largely failed to deliver their promises despite massive financial support. While several common species have shown to react positively to existing measures, rare species have continued to decline in most European countries. Of particular concern is the status of insectivorous farmland birds that forage on the ground. We modelled the foraging habitat preferences of four declining insectivorous bird species (hoopoe, wryneck, woodlark, common redstart inhabiting fruit tree plantations, orchards and vineyards. All species preferred foraging in habitat mosaics consisting of patches of grass and bare ground, with an optimal, species-specific bare ground coverage of 30-70% at the foraging patch scale. In the study areas, birds thrived in intensively cultivated farmland where such ground vegetation mosaics existed. Not promoted by conventional agri-environment schemes until now, patches of bare ground should be implemented throughout grassland in order to prevent further decline of insectivorous farmland birds.

  20. Models for calculating phreatic water evaporation on bare and Tamarix-vegetated lands

    Institute of Scientific and Technical Information of China (English)

    HU Shunjun; TIAN Changyan; SONG Yudong; CHEN Xiaobing; LI Yuetan

    2006-01-01

    Groundwater is the main source of water consumption of natural vegetation in arid regions.It is an effective approach to study ecological water demand of natural vegetation by phreatic evaporation.In order to study the ecological water demand of Tarim river basin, based on the observation data of phreatic evaporation on bare lands at the Aksu Water Balance Experimental station from 1989 to 1996, by analyzing the relationship of phreatic evaporation,depth of phreatic surface and evaporation of water,taking the limit rate of phreatic evaporation as the control condition, and based on the objective law that the relation between phreatic evaporation and evaporation of water is nonlinear, we establish models for calculating phreatic evaporation on bare land,which can fully reflect the law of phreatic evaporation in the Tarim river basin. According to the data of depth of phreatic surface and soil moisture when pheratic level decline is caused just by evapotranspiration on Tamarix-vegetated land from 2003 to 2004, we calculate the amount of phreatic evaporation and set up models for calculating phreatic evaporation on Tamarix- vegetated land. Phreatic evaporation on bare land and Tamarix-vegetated land could be transformed each other by a Tamarix vegetation conversion coefficient. The test results show that the calculation accuracy of the models is high and the models are suitable for Tarim river basin.