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Sample records for absorption root

  1. Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots

    Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface area are also discussed. When normalizing the total, adsorption and absorption PAH fractions on a dry root weight basis to root biomass, root lipid, and surface area bases respectively, the differences between PAHs in the two types of roots diminished by 2 to 3 times on average. Results from sequential extraction indicated that PAHs were more easily absorbed by interior rice roots than adsorbed on the surface. In addition, more than 60% of total PAHs accumulated in root tissue for both lateral and nodal roots. However, the results were highly related to the solvent used, extraction time and methodology. Correlation analysis between bioconcentration factors (root over environment) and K OA, K OW showed water to be more significant for PAH adsorption in rice roots than other environmental media. - A sequential extraction method was applied to divide the PAHs accumulated on rice roots into PAHs in root exudates, PAHs adsorbed on root surfaces, and PAHs absorbed in root tissue

  2. Plant root absorption and metabolic fate of technetium in plants

    In this series of studies with TcO4-, root absorption characteristics and tissue distributions are discussed and the chemical fate of Tc in plants is described and compared with that of Selenium and Sulphur. Vegetable and agricultural species used included the carrot, cabbage, lettuce, pea, mustard, radish, leek, bunch and bulb onion, soybean, alfalfa and garlic. (UK)

  3. Absorption behavior of technetium and rhenium through plant roots

    The absorption behavior of technetium (Tc) and rhenium (Re) through plant roots was studied using nutrient solution culture. Radish samples, grown in culture solutions for 20-30 days in a green house, were transferred into plastic vessels containing nutrient solutions contaminated with multi-tracer solutions including Tc-95m and Re-183. The plant samples were grown individually for 1-7 days under laboratory conditions. The activities of radionuclides in nutrient solutions and oven-dried plant parts (roots, fleshy roots and leaves) were measured with Ge detecting systems. The concentrations of Tc-95m and Re-183 in the nutrient solutions after harvesting the plants were almost the same as those in the initial solution. Possibly, the radionuclides were taken up with water through plant roots. The distributions of Tc and Re in the plants showed no differences, thus, soluble Tc and Re absorption by plant samples were the same. It is suggested that Re could be used as a geochemical tracer of Tc in the soil environment. (author)

  4. Iron absorption by roots of fruit plants : some characteristics of the phenomena

    Using young plants of peach, plum and almond growing in water culture, study was undertaken on the absorption and translocation of labelled iron. When peach plants deficient in this element were supplied with it, they tended to absorb it very rapidly, especially during the first 30 minutes. This absorption was not a superficial adsorption. Iron absorption was found to be linked to the length of non-lignified roots. Of the three species, almond absorbed more iron than peach but less than olum. No significant varietal difference was found regarding the iron absorption capacity of roots of different varieties of peach. Removal of foliage did not influence the absorption of iron by roots of peach plants in the early stages. (auth.)

  5. Distribution of radiosodium in the various organs of Sorghum after root absorption

    The kinetics of Na22 migration corroborate the distribution pattern of the non-radioactive element after root absorption: the sodium content of the leaf laminae is very low whereas a building-up is observed in the conductive tissues, particularly in the roots. After absorption, sodium seems to be rapidly translocated to all the organs, then moves downwards to accumulate in the roots; this phenomenon may be a way, for the plant, to fight sodium intoxication. The absorption of radiosodium is independent of the specific activity of the nutrient solution and appears to be related to its volumic activity. Thus, sodium is not taken up selectively by the roots of Sorghum; its translocation mechanism is therefore of the passive type

  6. Irradiation seed treatment reduces scald, common root rot and increases phosphorus absorption of barley

    The effect of low doses of gamma irradiation on severity of barley to scald and common root rot diseases, and phosphorus absorption was studied seeds were exposed to doses of 0, 10, 15, 20, 30, 40 and 50 Gy. A stimulatory effect was observed at irradiation doses of 30 and 40 Gy, which decreased the severity of barley to scald by 34% and 31% respectively. On the other hand, doses 20 and 30 Gy decreased the severity to CRR by 54% and 49% respectively, whereas, phosphorus absorption was significantly increased at doses of 15 and 20 Gy

  7. Inhibition of white light of 86Rb+ absorption in the root apex of corn

    Measurements of cell lengths made at 0.5 millimeter intervals in median longitudinal sections of the primary roots of corn (Zea mays) were used to construct a growth curve. The region 1.5 to 4.0 millimeters from the apex contained the largest number of elongating cells. Absorption of 86Rb+ was measured using intact, dark-grown corn seedlings. Following uptake and exchange, the terminal 8.0 millimeters of each root was cut into four 2.0 millimeter segments. Maximum 86Rb+ uptake occurred in the region from 0.0 to 4.0 millimeter from the root tip. Washing the intact primary root in fresh 2.0 millimolar CaSO4 for 2 hours prior to uptake augmented the rate of 86Rb+ uptake in all regions. Illumination with white light during washing caused a reduction of 86Rb+ uptake as compared with controls washing in darkness, and the region of greatest light response was the region of elongation. Removal of the coleoptile prior to washing did not prevent the light inhibition of subsequent 86Rb+ uptake. Removal of the root cap prior to washing in light partially reversed the light-induced inhibition of the washing response

  8. Estimating the absorptive root area in Norway spruce by using the common direct and indirect earth impedance methods

    Čermák, J.; Cudlín, Pavel; Gebauer, R.; Borja, I.; Martinková, M.; Staněk, Z.; Koller, J.; Neruda, J.; Nadezhdina, N.

    2013-01-01

    Roč. 372, 1-2 (2013), s. 401-415. ISSN 0032-079X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk OC10023 Institutional support: RVO:67179843 Keywords : Active absorptive fine root area index * Fine root surface * Modified earth impedance * Picea abies * Root research methods Subject RIV: EH - Ecology, Behaviour Impact factor: 3.235, year: 2013

  9. Absorption, distribution and utilization of radioactive phosphorus in healthy and root (wilt) diseased coconut palms

    Radioactive KH2P32O4 was fed to coconut leaves and palms under laboratory and field conditions. In healthy palms the absorption of phosphorus by roots and its accumulation in spindle and first fully opened leaves was found to be significantly higher till 9th hr as compared to that of diseased palms, but at later stages the reverse pattern was observed. The time required for 32P to reach the spindle (top-most leaf) situated at 9.5 m height in both diseased and healthy palm was found to be 3 hr only. In contrast to the leaves, the activity of 32P differed insignificantly in stem and roots of healthy and diseased palms and also the native P remained higher in the stem and roots of former palms as compared to latter. The analysis of total different fractions of phosphorus and entry of 32P in the different forms of organic phosphorus indicated that although total P was more in the case of diseased palms but the organic phosphorus especially the nucleic acid P was significantly less as compared to healthy ones. This revealed less utilization of absorbed P in the synthesis of P-constituted organic substances in diseased palms. (auth.)

  10. Effects of arbuscular mycorrhizal fungi on leaf solutes and root absorption areas of trifoliate orange seedlings under water stress conditions

    WU Qiangsheng; XIA Renxue

    2006-01-01

    The effects of the arbuscular mycorrhizal (AM)fungus Glomus mosseae on plant growth,leaf solutes and root absorption area of trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings were studied in potted culture under water stress conditions.Inoculation with G.mosseae increased plant height,stem diameter,leaf area,shoot dry weight,root dry weight and plant dry weight,when the soil water content was 20%,16% and 12%.AM inoculation also promoted the active and total absorption area of root system and absorption of phosphorus from the rhizosphere,enhanced the content of soluble sugar in leaves and roots,and reduced proline content in leaves.AM seedlings had higher plant water use efficiency and higher drought tolerance than non-AM seedlings.Effects of G.mosseae inoculation on trifoliate orange seedlings under 20% and 16% soil water content were more significant than under 12% soil water content.AM infection was severely restrained by 12% soil water content.Thus,effects of AM fungi on plants were probably positively related to the extent of root colonization by AM fungi.The mechanism of AM fungi in enhancing drought resistance of host plants ascribed to greater osmotic adjustment and greater absorption area of root system by AM colonization.

  11. Effects of the soil aeration on nutrient absorption, 14C-assimilates distribution and storage root yield in sweet potato

    Using Ipomoea batatas (L.) Lam. cv Lushu7 and Xushu18 as materials, the effect of the soil aeration on mineral nutrition absorption, 14C-assimilates distribution in storage roots and storage root yield were studied. The results showed that the improved soil aeration could increase the content of potassium, calcium, manganese, boron and zinc in leaves, increase the content of potassium and calcium in storage roots, decrease the content of manganese, boron and zinc in storage roots, improve the transportation of 14C-assimilates, increase the starch content of storage roots and significantly increase the storage root yield. The role of mineral elements on improving the transportation of 14C-assimilates was discussed

  12. Evaluation of absorption of radionuclides via roots of plants at different growth stages

    Ambe, Shizuko [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1999-03-01

    For the environmental risk assessment of radionuclides and toxic elements which were released by nuclear power plants and factories, the absorption of trace elements by plants has been studied by a multitracer technique. The selective absorption coefficient, which is a parameter of an uptake model of radionuclides by plants, was determined for various radionuclides. The selective absorption coefficients of some elements varied greatly in experimental runs. Therefore, the selective absorption coefficients of radionuclides by komatsuna at different growth stages were determined. Moreover, the soil-to-plant transfer of radionuclides in komatsuna at different growth stages was studied. Extraction of the radionuclides from the soil was carried out in order to study the correlation between the transfer factor and the aging effect of the radionuclides in soil. The effect of soil acidity on the absorption of radionuclides in soybean and tomato was studied using the plants at different growth stages. (author)

  13. Root absorption of 222Rn and its transfer into above-ground plant organs

    Experimental data are given on the content of genetically related pairs of radionuclides (226Ra and 222Rn; 224Ra and 220Rn) in soils and the above-ground phytomass of plants growing on plots with differing genesis of the higher concentrations of natural radionuclides in soils. Methods for determining gaseous radionuclides in the above-ground phytomass are described. Different transport routes of 222Rn and 220Rn into above-ground plant organs are considered. The noted absence of balance between 222Rn and 226Ra in plants as well as higher 222Rn/226Ra ratios in the above-ground phytomass as compared to that of the root-containing soil layer (25- to 185-fold) appears to be accounted for by the root pathway of 222Rn uptake and transport of this radionuclide to above-ground plants organs. The existence of the root pathway for 222Rn uptake is proved by direct observations of daily radionuclide movement with bleeding sap in experiments on pumpkins. For the short-lived Rn isotopes, 220Rn and 218Rn, the root pathway of uptake and transport to the above-ground phytomass is less probable, and this causes a notable redistribution of gaseous radionuclides during their movement along the soil-plant route

  14. Absorption of Nickel, Chromium, and Iron by the Root Surface of Primary Molars Covered with Stainless Steel Crowns

    David Keinan

    2010-01-01

    Full Text Available Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ, was analyzed. An energy dispersive X-ray spectrometer (EDS was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (<.001. Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

  15. Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

    To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.)

  16. The kinetics of caesium absorption by roots of winter wheat and the possible consequences for the derivation of soil-to-plant transfer factors for radiocaesium

    Caesium (Cs) uptake in roots of winter wheat followed a dual pattern similar to that established for potassium uptake in barley roots. This suggests the operation of two discrete uptake systems for Cs. The 'System 1' (low concentration) uptake mechanism for caesium, however, can be resolved into two hyperbolic components which both obey Michaelis-Menten kinetics. The Michaelis-Menten equation was used to derive a function which describes the variation in solution-to-root transfer factor for any element for which the appropriate root uptake constants (Km and Vmax) can be determined. This function successfully described available data for root uptake of caesium and potassium, predicting that the solution-to-root transfer factor decreases in relation to an increase in the substrate concentration of each respective element. At substrate concentrations equivalent to carrier-free radiocaesium concentrations, however, the solution-to-root transfer factor predicted by the function and by empirical data suggests that the relationship between root uptake and solution concentration of caesium is linear. These findings are discussed in relation to the comparative physiology of caesium and potassium uptake by plant roots and with respect to radioecological studies. (author)

  17. Inductively coupled plasma-emission spectroscopy and atomic absorption for the use of elemental analysis of a root canal after lasing with a holmium:YAG laser.

    Deutsch, Allan S; Cohen, Brett I; Musikant, Barry Lee

    2003-06-01

    It has been reported in the literature that after lasing dentin the dentin surface has a glassy or globular appearance. Many authors believe this to be recrystallized hydroxyapatite. The purpose of this elemental analysis was to see if any of the silica fiber optic was melted and deposited as these globular structures on the canal wall. Two teeth were used. One was hand-instrumented with files and used as the control, the other was lased with a holmium:YAG laser. A 245-micro low OH- fiber was used with a power setting of 0.75 W, 5 Hz, 94.2 J, and 1134 V to lase the root. The roots were microanalyzed for oxygen, phosphorus, silicon, nitrogen, hydrogen, calcium, and carbon. The percentages for all elements tested were the same for both teeth. Therefore, there was no silicon deposited onto the canal wall of the tooth that was lased. It is concluded that the low OH- silica fiber optic was not melted and deposited onto the dentinal canal wall. PMID:12814225

  18. Roots Revisited.

    Hughes, Barnabas

    1998-01-01

    Offers historical information about square roots. Presents three different methods--Hero's method, visual method, and remainder method--which can be used to teach the finding of square roots and one method for determining cube roots. (ASK)

  19. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors

  20. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp.

    Ayub, J. Juri; Valverde, L. Rubio; Garcia-Sanchez, M. J.; Fernandez, J. A.; Velasco, R. H.

    2008-08-01

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors.

  1. Root fractures

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  2. Square Root +

    Frederiksen, John G.

    1969-01-01

    A rational presentation of the so-called long division method for extracting the square root of a number. Diagrams are used to show relationship of this technique to the binomial theorem. Presentation exposes student to many facets of mathematics in addition to the mechanics of funding square root and cube root. Geometry, algebraic statements,…

  3. Roots & Hollers

    Kollman, Patrick L; Gorman, Thomas A.

    2011-01-01

    Roots & Hollers, 2011 A documentary by Thomas Gorman & Patrick Kollman Master’s Project Abstract: Roots & Hollers uncovers the wild American ginseng trade, revealing a unique intersection between Asia and rural America. Legendary in Asia for its healing powers, ginseng helps sustain the livelihoods of thousands in Appalachia. A single root can sell for thousands of dollars at auction. Shot on-location in the mountains of Kentucky and West Virginia, this student doc...

  4. 有机酸与根表铁膜对茶树吸收和富集氟的影响%Effects of organic acids and iron plaque outside roots on absorption and accumulation of fluoride in tea plants

    刘腾腾; 赵强; 郜红建; 宛晓春; 张正竹

    2013-01-01

    The effects of Fe2+ concentration,Fe2+ incubation time,pH and organic acids including oxalic acid,malic acid and citric acid on iron plaque on root surfaces and fluoride absorption and accumulation in tea plants were investigated in the hydroponics condition. Results showed that most of the iron plaque induced on tea roots was concentrated between 0. 2 cm and 0. 5 cm from the root tip. As the Fe2+ concentration and incubation time increased, the amount of iron plaque increased, but negative relationships were found when pH as well as organic acids concentrations increased. When the amount of iron plaque was 2.40 to 13. 60 mg·g-1,there was a positive relationship between fluoride adsorption and accumulation in tea plants and the iron plaque. Compared with CK1 without iron plaque and organic acids treatment, the amount of fluoride accumulated in tea plants increased between 42. 3% and 103. 7% with only Fe2+ treated. And it increased from 101.7% to 243.0% as the organic acids and Fe2+were added into the hydroponics solution together.%采用溶液培养法,研究了Fe2+质量浓度、Fe2+诱导时间、pH值、外源有机酸(草酸、苹果酸、柠檬酸)对根表铁膜形成及茶树吸收、富集氟的影响.结果表明:茶树根表铁膜主要集中在离根尖0.2~0.5 cm区域;茶树根表铁膜含量随Fe2+诱导时间的延长呈现先升高后降低的趋势,随Fe2+质量浓度的增加显著升高,与溶液pH、有机酸浓度呈负相关.当铁膜含量为2.40 ~ 13.60 mg·g-1,根表铁膜含量与茶树吸收、富集氟的能力呈正相关.与根表无铁膜的茶树单加氟处理的对照(CK1)相比,加Fe2+诱导形成铁膜后,茶树体内氟的含量增加了42.3% ~ 103.7%;有机酸与Fe2+共同作用时,茶树体内氟含量显著增加了101.7% ~243.0%.

  5. Root resorption

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost......-an ectodermal tissue layer (Malassez′s epithelium), a middle layer-composed by the collagen-mesodermal tissue layer, and an innermost root-close innervation layer. Abnormalities in one of these tissue layers are thought to cause inflammatory processes in the periodontal membrane comparable to inflammatory...

  6. Automated Root Tracking with "Root System Analyzer"

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  7. Root canal

    Endodontic therapy ... the root of a tooth. Generally, there is pain and swelling in the area. The infection can ... You may have some pain or soreness after the procedure. An over-the-counter anti-inflammatory drug, such as ibuprofen or naproxen, can help relieve ...

  8. Studies on the functions of different unit-roots and the grouping of roots in winter wheat

    The characteristics and functions of different unit-roots and their effects on the yield components in wheat were studied by means of 15N tracing technique. The root grouping was made by cluster analysis according to the function of different unit roots. The results were as follows: The unit-roots characters (weight, length etc.) and 15N absorption decreased progressively downward. 15N absorbed by any unit roots could be transported from root to tiller and from tiller to tiller, but the transporting ratio was different. According to the function, the wheat roots could be divided into 3 groups: primary root group, lower seconddary root group and upper secondary root group. The ratio of 15N absorption to the total N absorption in each group was 26.7%, 31.4% and 41.9% respectively. The differences among the three groups were that the primary root group functioned throughout whole life of wheat, mainly promoting tillers and increasing root numbers before winter; the lower secondary root group played the major role in strenthening tillers and promoting ear development; the upper secondary root group had the main function in determining the floret number, kernel number and kernel weight

  9. Cinética de absorção de K+ na ausência e presença de Na+ em raízes de cajueiro Kinetics of K+ absorption in the absence and presence of Na+ in roots cashew tree

    Francisco Abel Lemos Alves

    2012-09-01

    Full Text Available Um dos efeitos da salinidade causado por excesso de Na+ nos solos é a redução dos níveis de K+ nos tecidos vegetais. O trabalho objetivou caracterizar as vias de absorção de K+ de alta e baixa afinidade em raízes de cajueiro na ausência e presença de concentrações de Na+. Os estudos de cinética de absorção de K+ na ausência e presença de NaCl foram realizados com raízes destacadas de plântulas de cajueiro cultivadas sob privação de K+. O excesso de Na+ no meio externo causou redução da absorção de K+ pelos sistemas de alta e de baixa afinidade. A redução da absorção de K+, causada pelo excesso de Na+ no meio, nas raízes de cajueiro ocorre por mecanismo competitivo. Esse tipo de competição foi evidenciado pelo aumento dos valores de Km para a absorção de K+ induzido pelo Na+ externo, sem alterar os valores de Vmáx. Os resultados mostram que a salinidade pode comprometer a aquisição e a utilização de K+ em plantas de cajueiro.One effect of the salinity caused by an excess of Na+ in soils, is the reduction in levels of K+ in plant tissue. The study aimed to characterize the process of high and low-affinity absorption of K+ in cashew roots, in both the absence and presence of concentrations of Na+. Studies of the kinetics of K+ absorption in the absence and presence of NaCl were carried out using detached roots from cashew seedlings grown under K+ deprivation. The excess of Na+ in the external environment caused a reduction in K+ absorption by both the high and low-affinity systems. The reduction in the absorption of K+ in the roots of the cashew tree, caused by the excess Na+ in the environment, happens through competitive means. This type of competition was evidenced by the increase in Km values for the K+ absorption induced by the external Na+, without changing the values of Vmax. The results show that salinity may affect the acquisition and use of K+ in cashew plants.

  10. Absorption studies

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  11. Locally Finite Root Supersystems

    YOUSOFZADEH, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  12. Absorção e infiltração de água por raízes de batata-doce, através de ferimentos durante a lavagem Water absorption and infiltration in sweet-potato wound roots during washing

    Adonai Gimenez Calbo

    2000-09-01

    changes of root volume. Partially submerged intact roots and segments were less subject to intercellular water infiltration than the completely submerged ones. The mass increase of submerged intact roots was caused mainly by water absorption, a process which is known to exclude molecules with a size larger than a few nanometers. In transversely segmented roots most water entered by intercellular volume infiltration, which may introduce fungi spores and bacteria and other particles inside the damaged organ.

  13. Afrokoko Roots

    2011-01-01

    Give us a little background information about Afrokoko Roots.How long have you been performing together?It's an international Afrobeat outfit that I founded in Beijing three years ago.I founded it in order to show Chinese people that Africa is beyond what they see and hear on TV.For the purpose of cultural exchange,I hope it can help the Chinese learn about African culture,music,fashion,history and much more.Our band features two dancers,two backup singers,two percussionists,four brass players,a keyboard player,a guitar player and a drummer- and me as the lead vocal,drummer and dancer,which makes for live performances that are equally exciting sonically as they are visually.We have been traveling around,and so far,we have toured and performed in many Chinese cities such as Dalian (Liaoning Province),Hohhot (Inner Mongolia Autonomous Region) and Haikou (Hainan Province).

  14. A Pharmacology Study on the Absorption of Lead and Zinc in Roots of Arabis alpinal var.Parviflora Franch%小花南芥根(Arabis alpinal var.parviflora Franch)对铅锌吸收的药理学研究

    王吉秀; 太光聪; 祖艳群; 李元; 陈海燕

    2011-01-01

    以药理学的方法进行水培试验,研究小花南芥根对铅锌的吸收机理.结果表明:小花南芥在50 μm01/L的解偶联剂DNP处理12 h、24 h和36 h后与对照相比根中铅的浓度分别增加了4.4倍,7.1倍和1.7倍,ATP酶抑制剂Na3VO4作用下,则下降了O.64倍,0.76倍和0.69倍;而小花南芥在50μmol/L的解偶联剂DNP处理24 h和36 h后与对照相比根中锌的浓度分别下降了8.8%和5.4%,ATP酶抑制剂Na3VO4处理对小花南芥根吸收锌不产生影响.钾离子通道抑制剂TEA处理,小花南芥根吸收铅受到明显的抑制作用,不同处理与对照相比下降范围在0.51~0.82倍之间,钙离子通道抑制剂LaC13处理,下降范围在0.50~0.97倍之间,而小、花南芥根吸收锌在TEA处理12 h和24 h后与对照相比下降了0.94倍和0.58倍,LaC13处理24 h和36 h后与对照相比下降了6.6%倍和9.4%.从上述分析知,能量代谢和离子通道抑制剂对于小花南芥根部铅的吸收产生的影响大于锌的吸收.%The water culture experiment is to study the mechanism of Arabis alpinal Var.parviflora Franch's absorption in Lead and Zinc with a pharmacological approach.The findings show that after the 50 μmol/L uncoupler DNP treatment 12 h, 24 h and 36 h, the concentration of lead of Arabis alpinal Var.panrviflora Franch' s roots increases by 4.4 times, 7.1 times and 1.7 times compared with the control ones.Under the action of ATP inhibitors Na3VO4, the concentration decreases 0.64 times, 0.76 times and 0.69 times.However,after the 50 μmol/L uncoupler DNP treatment 12 h, 24 h and 36 h, the concentration of zinc of Arabis alpinal Var.parviflora Franch' s roots decreases by 8.8 times and 5.4 times.The action of ATP inhibitors Na3VO4 has no impact on the zinc absorption of Arabis alpinal Var.parviflora Franch.Under the potassium channel inhibitor TEA treatment, Arabis alpinal Var.parviflora Franch' s root absorption of lead was significantly restrained.The decreased range is between

  15. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production. PMID:26499883

  16. Collection of gravitropic effectors from mucilage of electrotropically-stimulated roots of Zea mays L

    Fondren, W. M.; Moore, R.

    1987-01-01

    We placed agar blocks adjacent to tips of electrotropically stimulated primary roots of Zea mays. Blocks placed adjacent to the anode-side of the roots for 3 h induced significant curvature when subsequently placed asymmetrically on tips of vertically-oriented roots. Curvature was always toward the side of the root unto which the agar block was placed. Agar blocks not contacting roots and blocks placed adjacent to the cathode-side of electrotropically stimulated roots did not induce significant curvature when placed asymmetrically on tips of vertically-oriented roots. Atomic absorption spectrophotometry indicated that blocks adjacent to the anode-side of electrotropically-stimulated roots contained significantly more calcium than (1) blocks not contacting roots, and (2) blocks contacting the cathode-side of roots. These results demonstrate the presence of a gradient of endogenous Ca in mucilage of electrotropically-stimulated roots (i.e. roots undergoing gravitropic-like curvature).

  17. Root canal irrigants

    Kandaswamy Deivanayagam; Venkateshbabu Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

  18. Associating rice root morphology and physiological traits with grain mineral concentrations of 24 varieties with extreme mineral compositions

    The first step towards mineral accumulation in plant seeds is the absorption/uptake of minerals from the soil by roots. Root physiological activities, such as root respiration and metabolism, modify physical (soil temperature), chemical (soil pH, redox potential, root exudates, allelochemicals, and ...

  19. Investigation of VEGGIE Root Mat

    Subbiah, Arun M.

    2013-01-01

    VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve

  20. Identiifcation and validation of root-speciifc promoters in rice

    HUANG Li-yu; ZHANG Fan; QIN Qiao; WANG Wen-sheng; ZHANG Ting; FU Bin-ying

    2015-01-01

    Novel promoters that confer root-speciifc expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-speciifc expression in rice. The isolation and characterization of upstream promoter regions of ifve selected genes rice root-speciifc promoter (rRSP) 1 to 5 (rRSP1-rRSP5) and A2P (the promoter ofOsAct2) revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-speciifc activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-speciifc enhancement of target gene(s).

  1. Using Square Roots

    Wilson, William Wynne

    1976-01-01

    This article describes techniques which enable the user of a comparatively simple calculator to perform calculations of cube roots, nth roots, trigonometric, and inverse trigonometric functions, logarithms, and exponentials. (DT)

  2. WHY ROOTING FAILS.

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  3. Root canal irrigation

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  4. The Root Canal Biofilm

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  5. Auxin, the organizer of the hormonal/environmental signals for root hair growth

    Lee, Richard D.-W.; Cho, Hyung-Taeg

    2013-01-01

    The root hair development is controlled by diverse factors such as fate-determining developmental cues, auxin-related environmental factors, and hormones. In particular, the soil environmental factors are important as they maximize their absorption by modulating root hair development. These environmental factors affect the root hair developmental process by making use of diverse hormones. These hormonal factors interact with each other to modulate root hair development in which auxin appears ...

  6. Effects of Nitrogen of Different Forms on Sorghum Sudanense Root Morphology and Characteristics of Lead Absorption and Accumulation Under Lead Stress%不同氮形态对铅胁迫下苏丹草根系形态及铅吸收富集特征的影响

    袁菊红; 胡绵好; 殷乾亮; 陈祎

    2012-01-01

    Effect of nitrogen of different forms on Sorghum sudanense root morphology and lead(Pb) absorption and accumulation under Pb stress were studied using hydroponics experiment,addressing the interaction between the plant and different nitrogen forms and heavy metals for phytoremediation application.The results indicate that the different N forms had some insignificant effects on the root morphology of S.sudanense with Pb pollution level of 0.5 mmol/L.However,the MDA(Malon dialde hyde)contents of the roots and the biomass of each organ of S.sudanense were significantly(p0.05) influenced: the MDA content of S.sudanense root in the NH4—N culture solution was 4.6 and 1.6 times higher than those in NO3—N and NO2—N culture solutions,and the root,stem and leave biomasses in the NO3—N culture solution were higher than those in NH4—N culture solution by 28.7%,19.6% and 23.9%,and higher than those in NO2—N culture solution by 37.6%,30.9% and 36.7%,respectively.With Pb pollution level of 0.5 mmol/L,the root in NO3—N treatment had the largest enrichment coefficients and Pb concentration that was over 2 times higher than that in NH4—N culture solution,and Pb concentration of the stem in the NO2—N treatment was over 8 times higher than that of NH4—N treatment,indicating a high transport capability of Pb.This suggests that if the existence of different forms of nitrogen in the eutrophication water with heavy metal pollution may to some extent weaken the toxic effect of the heavy metal on the remediating plant,and increase the environment capacity of the water.%为进一步研究富营养化水体中不同氮形态和重金属对修复植物的交互作用,通过水培试验研究了水体中不同形态氮培养对铅胁迫下苏丹草根系形态及其对铅吸收富集的影响。结果表明,水体Pb(0.5mmol/L)污染时,不同氮形态培养虽然对苏丹草根系形态有一定的影响,但没达到显著性差异,然而对苏丹草根系

  7. Nitrogen uptake and assimilation by corn roots

    The site of nitrogen uptake in the apical root zone of corn was experimentally investigated. Two experiments were performed. The one is to see the assimilation of nitrate and ammonium and the effects of low temperature on it. The 4-day-old roots were treated with 15N-labelled inorganic nitrogen of 20 ppm N in 5 x 10-4M CaSO4 solution at 30 deg. C and 0 deg. C. The other is to see the nitrogen uptake at apical root zone and the utilization of newly absorbed nitrogen at the root top. The 4-day-old roots were transferred into 5 x 10-4M CaSO4 solution containing 15N-labelled ammonium nitrate of 40 ppm N. As a result, the effect of low temperature on the nitrogen uptake appeared to be more drastic in the case of nitrate than ammonium. The 15N content of amino acids indicates that ammonium is assimilated into amino acids even at 0 deg. C, but nitrate is not. The ammonium nitrogen seemed to be absorbed at both cell dividing and elongating zones. On the other hand, nitrate nitrogen seemed to be strongly absorbed at cell elongating zone. The nitrogen in the apical part may be supplied not only by direct absorption but also by translocation from the basal part. The clear difference was found in the utilization of nitrate and ammonium nitrogen at the root top when the root was elongating. This may be due to the difference of assimilation products of inorganic nitrogen. Newly absorbed ammonium nitrogen is more utilizable for the growth of root top than nitrate nitrogen. (Iwakiri, K.)

  8. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera)

    Kumar Ramesh R.; Reddy Anjaneya Prasanna L.; Subbaiah Chinna J.; Kumar Niranjana A.; Prasad Nagendra H.N.; Bhukya Balakishan

    2011-01-01

    Ashwagandha (Withania somnifera) is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes) and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant) and crude fiber content exhibited strong association among them and ...

  9. Root canal irrigants

    Kandaswamy Deivanayagam

    2010-01-01

    Full Text Available Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ′root canal irrigants′ and ′endodontic irrigants.′ The reference lists of each article were manually checked for additional articles of relevance.

  10. Roots and routes

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between the...... somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  11. Roots of Dehn twists

    McCullough, Darryl; Rajeevsarathy, Kashyap

    2009-01-01

    D. Margalit and S. Schleimer found examples of roots of the Dehn twist about a nonseparating curve in a closed orientable surface, that is, homeomorphisms whose nth power is isotopic to the Dehn twist. Our main theorem gives elementary number-theoretic conditions that describe the values of n for which an nth root exists, given the genus of the surface. Among its applications, we show that n must be odd, that the Margalit-Schleimer roots achieve the maximum value of n among the roots for a gi...

  12. Chromatic roots and hamiltonian paths

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result is...

  13. D-xylose absorption

    ... this page: //medlineplus.gov/ency/article/003606.htm D-xylose absorption To use the sharing features on this page, please enable JavaScript. D-xylose absorption is a laboratory test to determine ...

  14. D-xylose absorption

    D-xylose absorption is a laboratory test to determine how well the intestines absorb a simple sugar (D-xylose). The test ... test is primarily used to determine if nutrient absorption problems are due to a disease of the ...

  15. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium absorption was neither affected by soybean protein in the diet nor by supplemental phytate. The inhibitory influence of soybean protein and phytate on apparent magnesium absorption was found to be cau...

  16. Anomalous water absorption in porous materials

    Lockington, D A

    2003-01-01

    The absorption of fluid by unsaturated, rigid porous materials may be characterized by the sorptivity. This is a simple parameter to determine and is increasingly being used as a measure of a material's resistance to exposure to fluids (especially moisture and reactive solutes) in aggressive environments. The complete isothermal absorption process is described by a nonlinear diffusion equation, with the hydraulic diffusivity being a strongly nonlinear function of the degree of saturation of the material. This diffusivity can be estimated from the sorptivity test. In a typical test the cumulative absorption is proportional to the square root of time. However, a number of researchers have observed deviation from this behaviour when the infiltrating fluid is water and there is some potential for chemo-mechanical interaction with the material. In that case the current interpretation of the test and estimation of the hydraulic diffusivity is no longer appropriate. Kuentz and Lavallee (2001) discuss the anomalous b...

  17. Influence of Topography on Root Processes in the Shale Hills-Susquehanna Critical Zone Observatory

    Eissenstat, D. M.; Orr, A. S.; Adams, T. S.; Chen, W.; Gaines, K.

    2015-12-01

    Topography can strongly influence root and associated mycorrhizal fungal function in the Critical Zone. In the Shale Hills-Susquehanna Critical Zone Observatory (SSCZO), soil depths range from more than 80 cm deep in the valley floor to about 25 cm on the ridge top. Tree height varies from about 28 m tall at the valley floor to about 17 m tall at the ridge top. Yet total absorptive root length to depth of refusal is quite similar across the hillslope. We find root length density to vary as much at locations only 1-2 m apart as at scales of hundreds of meters across the catchment. Tree community composition also varies along the hillslope, including tree species that vary widely in thickness of their absorptive roots and type of mycorrhiza (arbuscular mycorrhizal and ectomycorrhizal). Studies of trees in a common garden of 16 tree species and in forests near SSCZO indicate that both root morphology and mycorrhizal type can strongly influence root foraging. Species that form thick absorptive roots appear more dependent on mycorrhizal fungi and thin-root species forage more by root proliferation. Ectomycorrhizal trees show more variation in foraging precision (proliferation in a nutrient-rich patch relative to that in an unenriched patch) of their mycorrhizal hyphae whereas AM trees show more variation in foraging precision by root proliferation, indicating alternative strategies among trees of different mycorrhizal types. Collectively, the results provide insight into how topography can influence foraging belowground.

  18. ROOT User Workshop 2013

    2013-01-01

    Since almost two decades, ROOT has established itself as the framework for HENP data processing and analysis. The LHC upgrade program and the new experiments being designed at CERN and elsewhere will pose even more formidable challenges in terms of data complexity and size. The new parallel and heterogeneous computing architectures that are either announced or already available will call for a deep rethinking of the code and the data structures to be exploited efficiently. This workshop, following from a successful series of such events, will allow you to learn in detail about the new ROOT 6 and will help shape the future evolution of ROOT.

  19. Quantitative measurements of root water uptake and root hydraulic conductivities

    Zarebanadkouki, Mohsen; Javaux, Mathieu; Meunier, Felicien; Couvreur, Valentin; Carminati, Andrea

    2016-04-01

    How is root water uptake distributed along the root system and what root properties control this distribution? Here we present a method to: 1) measure root water uptake and 2) inversely estimate the root hydraulic conductivities. The experimental method consists in using neutron radiography to trace deuterated water (D2O) in soil and roots. The method was applied to lupines grown aluminium containers filled with a sandy soil. When the lupines were 4 weeks old, D2O was locally injected in a selected soil regions and its transport was monitored in soil and roots using time-series neutron radiography. By image processing, we quantified the concentration of D2O in soil and roots. We simulated the transport of D2O into roots using a diffusion-convection numerical model. The diffusivity of the roots tissue was inversely estimated by simulating the transport of D2O into the roots during night. The convective fluxes (i.e. root water uptake) were inversely estimating by fitting the experiments during day, when plants were transpiring, and assuming that root diffusivity did not change. The results showed that root water uptake was not uniform along the roots. Water uptake was higher at the proximal parts of the lateral roots and it decreased by a factor of 10 towards the distal parts. We used the data of water fluxes to inversely estimate the profile of hydraulic conductivities along the roots of transpiring plants growing in soil. The water fluxes in the lupine roots were simulated using the Hydraulic Tree Model by Doussan et al. (1998). The fitting parameters to be adjusted were the radial and axial hydraulic conductivities of the roots. The results showed that by using the root architectural model of Doussan et al. (1998) and detailed information of water fluxes into different root segments we could estimate the profile of hydraulic conductivities along the roots. We also found that: 1) in a tap-rooted plant like lupine water is mostly taken up by lateral roots; (2) water

  20. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  1. Calcium absorption and achlorhydria

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  2. Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes.

    McCormack, M Luke; Dickie, Ian A; Eissenstat, David M; Fahey, Timothy J; Fernandez, Christopher W; Guo, Dali; Helmisaari, Heljä-Sisko; Hobbie, Erik A; Iversen, Colleen M; Jackson, Robert B; Leppälammi-Kujansuu, Jaana; Norby, Richard J; Phillips, Richard P; Pregitzer, Kurt S; Pritchard, Seth G; Rewald, Boris; Zadworny, Marcin

    2015-08-01

    Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine-root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine-root orders. Here, we demonstrate how order-based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter-lived absorptive pool and a longer-lived transport fine-root pool. Using these frameworks, we estimate that fine-root production and turnover represent 22% of terrestrial net primary production globally - a c. 30% reduction from previous estimates assuming a single fine-root pool. Future work developing tools to rapidly differentiate functional fine-root classes, explicit incorporation of mycorrhizal fungi into fine-root studies, and wider adoption of a two-pool approach to model fine roots provide opportunities to better understand below-ground processes in the terrestrial biosphere. PMID:25756288

  3. Variability of calcium absorption

    Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo. Fifty absorption tests were performed in 22 subjects. Each was done in the morning after an overnight fast with an identical standard breakfast containing a Ca load of approximately 250 mg. Individual fractional absorption values were normalized to permit pooling of the data. The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration. One other published study presenting replicate absorption values was analyzed in a similar fashion and was found to have a CV of absorption of 9.78%. From these data we estimate that when the standard double-isotope method is used to measure Ca absorption there is approximately 10% variability around any given absorption value within an individual human subject and that roughly two-thirds of this represents real biological variability in absorption

  4. The "Green" Root Beer Laboratory

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  5. Root development under drought stress

    Franco Leemhuis, José Antonio

    2011-01-01

    Serving as interfaces between plant and the soil, roots are much more exposed to drought stress than the upper plant parts. Therefore, the root system can be as affected, or even more affected, than the aerial parts of the plant for drought stress (Franco et al., 2011). Nevertheless, the influence of this stress on root activity and development has been much less studied. Undoubtedly, this is due to limitations on accessibility for root observations; being studies on root system dynamics espe...

  6. Discussion on Photoreceptor for Negative Phototropism in Rice Roots

    WANG Yue-xia; WANG Zhong; SUO Biao; GU Yun-jie; WANG Hui-hui; CHEN Yong-hui; DAI Yun-xia

    2007-01-01

    To properly explore the photoreceptor for the negative phototropism in rice (Oryza sativa L.) root, lights with different wavelengths were applied to investigate the effect of light quality on phototropic bending. The phototropic bending could be induced prominently by blue/ultraviolet light, whereas not by red or far-red light. The absorption spectrum of the extracted solution from rice root cap had two peaks at 350 nm and 450 nm, respectively, and the molecular weight of the 120 kD protein in the root cap under unilateral light was larger than that under the dark. It suggested that the blue light receptor might be the photoreceptor for the negative phototropism in rice root.

  7. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium abs

  8. Zeeman atomic absorption spectroscopy

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  9. Petawatt laser absorption bounded

    Levy, Matthew C; Tabak, Max; Libby, Stephen B; Baring, Matthew G

    2014-01-01

    The interaction of petawatt ($10^{15}\\ \\mathrm{W}$) lasers with solid matter forms the basis for advanced scientific applications such as table-top particle accelerators, ultrafast imaging systems and laser fusion. Key metrics for these applications relate to absorption, yet conditions in this regime are so nonlinear that it is often impossible to know the fraction of absorbed light $f$, and even the range of $f$ is unknown. Here using a relativistic Rankine-Hugoniot-like analysis, we show for the first time that $f$ exhibits a theoretical maximum and minimum. These bounds constrain nonlinear absorption mechanisms across the petawatt regime, forbidding high absorption values at low laser power and low absorption values at high laser power. For applications needing to circumvent the absorption bounds, these results will accelerate a shift from solid targets, towards structured and multilayer targets, and lead the development of new materials.

  10. Auxin, the organizer of the environmental/hormonal signals for root hair growth

    Hyung-Taeg eCho

    2013-11-01

    Full Text Available The root hair development is controlled by diverse factors such as fate-determining developmental cues, auxin-related environmental factors, and hormones. In particular, the soil environmental factors are important as they maximize their absorption by modulating root hair development. These environmental factors affect the root hair developmental process by making use of diverse hormones. These hormonal factors interact with each other to modulate root hair development in which auxin appears to form the most intensive networks with the pathways from environmental factors and hormones. Moreover, auxin action for root hair development is genetically located immediately upstream of the root hair-morphogenetic genes. These observations suggest that auxin plays as an organizing node for environmental/hormonal pathways to modulate root hair growth.

  11. Produção de matéria seca, crescimento radicular e absorção de cálcio, fósforo e alumínio por coffea canephora e coffea arabica sob influência da atividade do alumínio em solução Dry matter production, root growth and calcium, phosphorus and aluminum absorption by coffea canephora and coffea arabica under influence of aluminum activity in solution

    Edson Marcio Mattiello

    2008-02-01

    Full Text Available Este trabalho teve como objetivo avaliar a produção de matéria seca, o crescimento radicular e a absorção e distribuição do Ca, P e Al nas folhas, no caule e nas raízes de dois clones de café conilon (Coffea canephora (Mtl 25 e Mtl 27 e de uma variedade de café Catuaí Amarelo (Coffea arabica, cultivados em solução nutritiva com atividade crescente de Al3+. As plantas foram cultivadas em vasos com capacidade para 5 L, contendo solução nutritiva de Hoagland & Arnon, modificada. Após oito dias de adaptação, as plantas foram submetidas a concentrações de Al de 0, 500, 1.000 e 2.000 µmol L-1, que corresponderam a atividades de Al3+ em solução, estimadas pelo software GEOCHEM, de 20,68, 50,59, 132,9 e 330,4 µmol L-1, respectivamente. Foram determinados os teores de Ca, Al e P na planta. O sistema radicular foi separado, para determinação da área e do comprimento. A variedade Catuaí Amarelo (Coffea arabica apresentou-se menos sensível ao Al3+, quando comparada aos clones de conilon (Coffea canephora. O clone de conilon Mtl 25 foi menos sensível ao Al3+ em relação ao Mtl 27. O aumento da atividade de Al3+ promoveu redução nos teores de P e Ca nas folhas e raízes do cafeeiro, especialmente nos clones Mtl 25 e Mtl 27. O acúmulo de Al no sistema radicular e a restrição do transporte para a parte aérea são importantes fatores na tolerância de plantas ao Al3+.This study had the objective of evaluating the dry matter production, root growth, and the absorption and distribution of Ca, P and Al in the leaves, stem and roots of two Conilon (Coffea canephora coffee clones (Mtl 25 and Mtl 27 and the coffee variety Catuaí Amarelo (Coffea arabica grown in nutrient solution with increasing Al3+ activity. The plants were cultivated in 5 L pots, containing modified Hoagland & Arnold nutrient solution. After eight days of adaptation, the plants were subjected to Al concentrations of 0, 500, 1.000 and 2.000 mol L-1, which

  12. Complex Roots of Quaternion Polynomials

    Dospra, Petroula; Poulakis, Dimitrios

    2015-01-01

    The polynomials with quaternion coefficients have two kind of roots: isolated and spherical. A spherical root generates a class of roots which contains only one complex number $z$ and its conjugate $\\bar{z}$, and this class can be determined by $z$. In this paper, we deal with the complex roots of quaternion polynomials. More precisely, using B\\'{e}zout matrices, we give necessary and sufficient conditions, for a quaternion polynomial to have a complex root, a spherical root, and a complex is...

  13. Root canal medicaments.

    Kawashima, Nobuyuki; Wadachi, Reiko; Suda, Hideaki; Yeng, Thai; Parashos, Peter

    2009-02-01

    The ultimate goals of endodontic treatment are complete removal of bacteria, their byproducts and pulpal remnants from infected root canals and the complete seal of disinfected root canals. Intracanal medicaments have been thought an essential step in killing the bacteria in root canals; however, in modern endodontics, shaping and cleaning may be assuming greater importance than intracanal medicaments as a means of disinfecting root canals. Until recently, formocresol and its relatives were frequently used as intracanal medicaments, but it was pointed out that such bactericidal chemicals dressed in the canal distributed to the whole body from the root apex and so might induce various harmful effects including allergies. Furthermore, as these medicaments are potent carcinogenic agents, there is no indication for these chemicals in modern endodontic treatment. Today, biocompatibility and stability are essential properties for intracanal medicaments. The more modern meaning of intracanal dressing is for a blockade against coronal leakage from the gap between filling materials and cavity wall. Calcium hydroxide has been determined as suitable for use as an intracanal medicament as it is stable for long periods, harmless to the body, and bactericidal in a limited area. It also induces hard tissue formation and is effective for stopping inflammatory exudates. Single-visit endodontics, where intracanal medicaments are not used, is generally not now contraindicated and various reports have shown that the clinical outcomes between single- and multiple- visit endodontics are similar. There is no reason to counsel against single-visit endodontics: however, if multiple-visit endodontics is chosen, calcium hydroxide is recommended to be used as an intracanal medicament. PMID:19323305

  14. Hairy roots are more sensitive to auxin than normal roots

    Shen, Wen Hui; Petit, Annik; Guern, Jean; Tempé, Jacques

    1988-01-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exo...

  15. Bioremediation of phenolic compounds from water with plant root surface peroxidases

    Adler, P.R.; Arora, R.; El Ghaouth, A. [West Virginia Univ., Morgantown, WV (United States)] [and others

    1994-09-01

    Peroxidases have been shown to polymerize phenolic compounds, thereby removing them from solution by precipitation. Others have studied the role of root surface associated peroxidases as a defense against fungal root pathogens; however, their use in detoxification of organic pollutants in vivo at the root surface has not been studied. Two plant species, waterhyacinth [Eichhornia crassipes (C. Mart) Solms-Laub.] and tomato (Lycopersicon esculentum L.), were tested for both in vitro and in vivo peroxidase activity on the root surface. In vitro studies indicated that root surface peroxidase activities were 181 and 78 nmol tetraguaiacol formed min{sup -1} g{sup -1} root fresh wt., for tomato and waterhyacinth, respectively. Light microscope studies revealed that guaiacol was polymerized in vivo at the root surface. Although peroxidase was evenly distributed on tomato roots, it was distributed patchily on waterhyacinth roots. In vitro studies using gas chromatography-mass spectrometry (GC-MS) showed that the efficiency of peroxidase to polymerize phenols vary with phenolic compound. We suggest that plants may be utilized as a source of peroxidases for removal of phenolic compounds that are on the EPA priority pollutant list and that root surface peroxidases may minimize the absorption of phenolic compounds into plants by precipitating them at the root surface. In this study we have identified a new use for root-associated proteins in ecologically engineering plant systems for bioremediation of phenolic compounds in the soil and water environment. 25 refs., 2 figs., 2 tabs.

  16. Root Morphology and Zn2+ Uptake Kinetics of the Zn Hyperaccumulator of Sedum alfredii Hance

    Ting-Qiang LI; Xiao-E YANG; Zhen-Li HE; Jin-Yan YANG

    2005-01-01

    Root morphology and Zn2+ uptake kinetics of the hyperaccumulating ecotype (HE) and nonhyperaccumulating ecotype (NHE) of Sedum alfredii Hance were investigated using hydroponic methods and the radiotracer flux technique. The results indicate that root length, root surface area, and root volume of NHE decreased significantly with increasing Zn2+ concentration in growth media, whereas the root growth of HE was not adversely affected, and was even promoted, by 500 μmol/L Zn2+. The concentrations of Zn2+ in both ecotypes of S. alfredii were positively correlated with root length, root surface area and root volumes, but no such correlation was found for root diameter. The uptake kinetics for 65Zn2+ in roots of both ecotypes of S. alfredii were characterized by a rapid linear phase during the first 6 h and a slower linear phase during the subsequent period of investigation. The concentration-dependent uptake kinetics of the two ecotypes of S. alfredii could be characterized by the Michaelis-Menten equation, with the Vmax for 65Zn2+ influx being threefold greater in HE compared with NHE, indicating that enhanced absorption into the root was one of the mechanisms involved in Zn hyperaccumulation. A significantly larger Vmax value suggested that there was a higher density of Zn transporters per unit membrane area in HE roots.

  17. Quasar Absorption Studies

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  18. Root Uptake of Lipophilic Zinc−Rhamnolipid Complexes

    Stacey, Samuel P.; McLaughlin, Michael J.; Cakmak, Ismail; Hettiarachchi, Ganga M.; Scheckel, Kirk G.; Karkkainen, Michael (Sabanci); (EPA); (CSIRO/LW); (Adelaide)

    2009-06-16

    This study investigated the formation and plant uptake of lipophilic metal-rhamnolipid complexes. Monorhamnosyl and dirhamnosyl rhamnolipids formed lipophilic complexes with copper (Cu), manganese (Mn), and zinc (Zn). Rhamnolipids significantly increased Zn absorption by Brassica napus var. Pinnacle roots in {sup 65}Zn-spiked ice-cold solutions, compared with ZnSO{sub 4} alone. Therefore, rhamnolipid appeared to facilitate Zn absorption via a nonmetabolically mediated pathway. Synchrotron XRF and XAS showed that Zn was present in roots as Zn-phytate-like compounds when roots were treated with Zn-free solutions, ZnSO{sub 4}, or Zn-EDTA. With rhamnolipid application, Zn was predominantly found in roots as the Zn-rhamnolipid complex. When applied to a calcareous soil, rhamnolipids increased dry matter production and Zn concentrations in durum (Triticum durum L. cv. Balcali-2000) and bread wheat (Triticum aestivum L. cv. BDME-10) shoots. Rhamnolipids either increased total plant uptake of Zn from the soil or increased Zn translocation by reducing the prevalence of insoluble Zn-phytate-like compounds in roots.

  19. The Physiology of Adventitious Roots.

    Steffens, Bianka; Rasmussen, Amanda

    2016-02-01

    Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding. They are important economically (for cuttings and food production), ecologically (environmental stress response), and for human existence (food production). To improve sustainable food production under environmentally extreme conditions, it is important to understand the adventitious root development of crops both in normal and stressed conditions. Therefore, understanding the regulation and physiology of adventitious root formation is critical for breeding programs. Recent work shows that different adventitious root types are regulated differently, and here, we propose clear definitions of these classes. We use three case studies to summarize the physiology of adventitious root development in response to flooding (case study 1), nutrient deficiency (case study 2), and wounding (case study 3). PMID:26697895

  20. Variation in root wood anatomy

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  1. Zeeman atomic absorption spectrometry

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given

  2. Hairy roots are more sensitive to auxin than normal roots.

    Shen, W H; Petit, A; Guern, J; Tempé, J

    1988-05-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogenous auxin concentration. The sensitivity of hairy root tips or protoplasts to exogenous auxin was found to be 100-1000 times higher than that of untransformed material. PMID:16593928

  3. Root canal retained restorations: 3. Root-face attachments.

    Dummer, P M; Edmunds, D H; Gidden, J R

    1990-10-01

    It has been common practice for many years to use retained roots to provide support and stability for partial or full dentures. The retention of such overdentures is greatly enhanced if the remaining roots are modified and restored with posts and root-face attachments. The final article in this series on root canal retained restorations classifies and describes some of the root-face attachments currently available, and also describes a number of prefabricated post systems with integral overdenture attachments. Guidelines for clinical and laboratory procedures are given. PMID:2097234

  4. Root discrimination of closely related crop and weed species using FT MIR-ATR spectroscopy

    Catharina eMeinen

    2015-09-01

    Full Text Available Root discrimination of species is a pre-condition for studying belowground competition processes between crop and weed species. In this experiment, we tested Fourier transform mid-infrared (FT MIR-attenuated total reflection (ATR spectroscopy to discriminate roots of closely related crop and weed species grown in the greenhouse: maize/barnyard grass, barley/wild oat, wheat/blackgrass (Poaceae, and sugar beet/common lambsquarters (Chenopodiaceae. Fresh (moist and dried root segments as well as ground roots were analyzed by FT MIR-ATR spectroscopy. Root absorption spectra showed species specific peak distribution and peak height. A clear separation according to species was not possible with fresh root segments. Dried root segments (including root basis, middle section and root tip of maize/barnyard grass and sugar beet/common lambsquarters formed completely separated species clusters. Wheat and blackgrass separated in species specific clusters when root tips were removed from cluster analysis. A clear separation of dried root segments according to species was not possible in the case of barley and wild oat. Cluster analyses of ground roots revealed a 100 % separation of all tested crop and weed species combinations. Spectra grouped in Poaceae and Chenopodiaceae clusters. Within the Poaceae cluster, C3 and C4 species differed significantly in heterogeneity. Thus, root spectra reflected the degree of kinship. To quantify species proportion in root mixtures, a two- and a three-species model for species quantification in root mixtures of maize, barnyard grass, and wild oat was calculated. The models showed low standard errors of prediction (RMSEP and high residual predictive deviation (RPD values in an external test set validation. Hence, FT MIR-ATR spectroscopy seems to be a promising tool for root research even between closely related plant species.

  5. Auxins differentially regulate root system architecture and cell cycle protein levels in maize seedlings.

    Martínez-de la Cruz, Enrique; García-Ramírez, Elpidio; Vázquez-Ramos, Jorge M; Reyes de la Cruz, Homero; López-Bucio, José

    2015-03-15

    Maize (Zea mays) root system architecture has a complex organization, with adventitious and lateral roots determining its overall absorptive capacity. To generate basic information about the earlier stages of root development, we compared the post-embryonic growth of maize seedlings germinated in water-embedded cotton beds with that of plants obtained from embryonic axes cultivated in liquid medium. In addition, the effect of four different auxins, namely indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on root architecture and levels of the heat shock protein HSP101 and the cell cycle proteins CKS1, CYCA1 and CDKA1 were analyzed. Our data show that during the first days after germination, maize seedlings develop several root types with a simultaneous and/or continuous growth. The post-embryonic root development started with the formation of the primary root (PR) and seminal scutellar roots (SSR) and then continued with the formation of adventitious crown roots (CR), brace roots (BR) and lateral roots (LR). Auxins affected root architecture in a dose-response fashion; whereas NAA and IBA mostly stimulated crown root formation, 2,4-D showed a strong repressing effect on growth. The levels of HSP101, CKS1, CYCA1 and CDKA in root and leaf tissues were differentially affected by auxins and interestingly, HSP101 registered an auxin-inducible and root specific expression pattern. Taken together, our results show the timing of early branching patterns of maize and indicate that auxins regulate root development likely through modulation of the HSP101 and cell cycle proteins. PMID:25615607

  6. Negative phototropism of rice root

    2001-01-01

    @@It is often believed that the stem of higher plants has characteristics of positive phototropism, and the root shows no phototropism or no sensitivity to light though the root of Arabdopsis was reported possessing characteristics of negative phototropism. In this study, a distinct negative phototropism of the root system of rice seedlings was observed.

  7. Effect of drought on the absorption of phosphorus in maize seedlings

    The absorption and transportation of H232PO4- and the role of Brassinolide (BR) and Ca2+ in phosphorus nutrition in maize seedlings were studied under drought conditions caused by PEG-Knop nutrient solution of -0.3 and -1.1 MPa osmotic pressure. The results indicated that the quantities of phosphorus absorbed and transported to leaves in maize seedlings decreased with the increase of drought intensity; phosphorus transportation to leaves was more sensitive to drought than absorption by roots; BR and Ca2+ had the effects of promoting root growth, increasing the surface area of absorption, relative water content in plants and ATP content in roots, and enhancing absorption and transportation of phosphorus

  8. Diagravitropism in corn roots

    Leopold, A. C.; Wettlaufer, S. H.

    1988-01-01

    The diagravitropic behavior of Merit corn (Zea mays L.) roots grown in darkness provides an opportunity for comparison of two qualitatively different gravitropic systems. As with positive gravitropism, diagravitropism is shown to require the presence of the root cap, have a similar time course for the onset of curvature, and a similar presentation time. In contrast with positive gravitropism, diagravitropism appears to have a more limited requirement for calcium, for it is insensitive to the elution of calcium by EGTA and insensitive to the subsequent addition of a calcium/EGTA complex. These results are interpreted as indicating that whereas the same sensing system is shared by the two types of gravitropism, separate transductive systems are involved, one for diagravitropism, which is relatively independent of calcium, and one for positive gravitropism, which is markedly dependent on calcium.

  9. Mental Roots of Terror

    Saruhan, Müfit Selim

    2004-01-01

    In this article, I deal with mental and terror relationship. Mental roots of terror are being examined. Religion has nothing to do with terrorism. Terrorist tries to misuse religion. Mental with prejudice and lack of knowledge occupies the personality of individual and his ability to judge. Purification of mind from any external and internal prejudices is the unique solution of terrorism. Only within extensive education we can overcome terrorism. Terrorism could not apply to a religion or a n...

  10. Rooted in Movement

    The result of the synergy between four doctoral projects and an advanced MA-level course on Bronze Age Europe, this integrated assemblage of articles represents a variety of different subjects united by a single theme: movement. Ranging from theoretical discussion of the various responses to and ...... period of European prehistory. In so doing, the text not only addresses transmission and reception, but also the conceptualization of mobility within a world which was literally Rooted in Movement....

  11. Roots of Financial Literacy

    Grohmann, Antonia; Kouwenberg, Roy; Menkhoff, Lukas

    2014-01-01

    Our study aims to uncover the roots of financial literacy. Better financial literacy predicts more informed savings and borrowing decisions in our sample, covering the urban middle-class in an emerging economy. We then test education at school, family background, parental teaching, and childhood experiences with money as potential determinants of financial literacy. In addition to risk tolerance and having basic numeracy skills, we find that family variables matter most, in particular better ...

  12. Seven-effect absorption refrigeration

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  13. Do roots mind the gap?

    A. Carminati; Vetterlein, D; Koebernick, N.; Blaser, S; Weller, U; Vogel, H.-J.

    2012-01-01

    Roots need to be in good contact with the soil to take up water and nutrients. However, when the soil dries and roots shrink, air-filled gaps form at the root-soil interface. Do gaps actually limit the root water uptake, or do they form after water flow in soil is already limiting?Four white lupins were grown in cylinders of 20 cm height and 8 cm diameter. The dynamics of root and soil structure were recorded using X-ray CT at regular intervals during one drying/wetting cycle. Tensiometers we...

  14. Effects of Aeration on Root Physiology and Nitrogen Metabolism in Rice

    XU Chun-mei; WANG Dan-ying; CHEN Song; CHEN Li-ping; ZHANG Xiu-fu

    2013-01-01

    In order to clarify the effects of aeration on root nitrogen metabolism in rice seedlings,rice cultivars Guodao 6 (indica) and Xiushui 09 (japonica) were investigated for root growth,the activities of glutamine synthetase (GS),glutamic acid-pyruvic acid transaminase (GPT) and glutamic acid oxaloacetate transaminase (GOT),the nitrate (NO3-N) concertration,the contents of free amino acids and soluble sugar in root under hydroponics with continuous aeration treatment.The results showed that rice seedlings grown in oxygenation solutions had higher root dry matter,longer root length,stronger root activity and larger root absorption area compared with the control.In addition,the contents of soluble sugar,root vigor and the activities of GS,GOT and GPT in the aeration solutions were higher than those in the control.The results also indicated that the activities of enzymes involved in root nitrogen metabolism of Xiushui 09 were enhanced by aeration,however,there was no significant influence on root nitrogen metabolism of Guodao 6,which suggested that effect of oxygenation on rice root nitrogen metabolism might be genotype-specific.

  15. Adsorption of Eu(III) onto roots of water hyacinth

    Kelley, C.; Mielke, R.E.; Dimaquibo, D.; Curtis, A.J. [Northern Arizona Univ., Flagstaff, AZ (United States). Dept. of Chemistry; Dewitt, J.G. [San Francisco State Univ., San Francisco, CA (United States)

    1999-05-01

    The water hyacinth (Eichhornia crassipes) has drawn attention as a plant capable of removing pollutants, including toxic metals, from water. The authors are interested in the capacity of the water hyacinth to remediate aquatic environments that have been contaminated with the lanthanide metal, europium Eu(III). Using scanning electron microscopy (SEM) they have been able to determine that Eu(III) is adsorbed onto the surface of the roots from water and that the highest concentration of Eu(III) is on the root hairs. X-ray absorption spectroscopy (XAS) techniques were used to speciate the Eu(III) adsorbed onto the surface of the roots. The XAS data for Eu-contaminated water hyacinth roots provides evidence of a Eu-oxygen environment and establishes that Eu(III) is coordinated to 10--11 oxygen atoms at a distance of 2.44 {angstrom}. This likely involves binding of Eu(III) to the root via carboxylate groups and hydration of Eu(III) at the root surface.

  16. Vitamin A absorption

    Investigation of the absorption of vitamin A and related substances is complicated by the multiplicity of forms in which they occur in the diet and by the possibility that they may be subject to different mechanisms of absorption. Present knowledge of these mechanisms is inadequate, especially in the case of carotenoids. Numerous tests of absorption have been developed. The most common has been the biochemical measurement of the rise in plasma vitamin A after an oral dose of retinol or retinyl ester, but standardization is inadequate. Radioisotope tests based upon assay of serum or faecal activity following oral administration of tritiated vitamin A derivaties hold considerable promise, but again standardization is inadequate. From investigations hitherto performed it is known that absorption of vitamin A is influenced by several diseases, although as yet the consistency of results and the correlation with other tests of intestinal function have often been poor. However, the test of vitamin A absorption is nevertheless of clinical importance as a specialized measure of intestinal function. (author)

  17. Central cooling: absorptive chillers

    Christian, J.E.

    1977-08-01

    This technology evaluation covers commercially available single-effect, lithium-bromide absorption chillers ranging in nominal cooling capacities of 3 to 1,660 tons and double-effect lithium-bromide chillers from 385 to 1,060 tons. The nominal COP measured at operating conditions of 12 psig input steam for the single-effect machine, 85/sup 0/ entering condenser water, and 44/sup 0/F exiting chilled-water, ranges from 0.6 to 0.65. The nominal COP for the double-effect machine varies from 1.0 to 1.15 with 144 psig entering steam. Data are provided to estimate absorption-chiller performance at off-nominal operating conditions. The part-load performance curves along with cost estimating functions help the system design engineer select absorption equipment for a particular application based on life-cycle costs. Several suggestions are offered which may be useful for interfacing an absorption chiller with the remaining Integrated Community Energy System. The ammonia-water absorption chillers are not considered to be readily available technology for ICES application; therefore, performance and cost data on them are not included in this evaluation.

  18. Percutaneous absorption from soil.

    Andersen, Rosa Marie; Coman, Garrett; Blickenstaff, Nicholas R; Maibach, Howard I

    2014-01-01

    Abstract Some natural sites, as a result of contaminants emitted into the air and subsequently deposited in soil or accidental industrial release, have high levels of organic and non-organic chemicals in soil. In occupational and recreation settings, these could be potential sources of percutaneous exposure to humans. When investigating percutaneous absorption from soil - in vitro or vivo - soil load, particle size, layering, soil "age" time, along with the methods of performing the experiment and analyzing the results must be taken into consideration. Skin absorption from soil is generally reduced compared with uptake from water/acetone. However, the absorption of some compounds, e.g., pentachlorophenol, chlorodane and PCB 1254, are similar. Lipophilic compounds like dichlorodiphenyltrichloroethane, benzo[A]pyrene, and metals have the tendency to form reservoirs in skin. Thus, one should take caution in interpreting results directly from in vitro studies for risk assessment; in vivo validations are often required for the most relevant risk assessment. PMID:25205703

  19. Studies on the uptake of phosphorous by corn root system

    Phosphorous absorbed by root system of corn at different depth and its distribution to various organs are studied by using 32P tracing method. The preliminary results revealed that phosphorous utilization rate in shallow application was the highest one. The pulses of 32P in various organs have been measured at mature stage of corn. There is no difference between shallow and deep applications in phosphorous absorption by kernels

  20. Philosophical Roots of Cosmology

    Ivanovic, M.

    2008-10-01

    We shall consider the philosophical roots of cosmology in the earlier Greek philosophy. Our goal is to answer the question: Are earlier Greek theories of pure philosophical-mythological character, as often philosophers cited it, or they have scientific character. On the bases of methodological criteria, we shall contend that the latter is the case. In order to answer the question about contemporary situation of the relation philosophy-cosmology, we shall consider the next question: Is contemporary cosmology completely independent of philosophical conjectures? The answer demands consideration of methodological character about scientific status of contemporary cosmology. We also consider some aspects of the relation contemporary philosophy-cosmology.

  1. Ion competition effects on the selective absorption of radionuclides by komatsuna (Brassica rapa var. perviridis)

    The selective absorption coefficient, which is a parameter of an uptake model of radionuclides by plants, was determined for various radionuclides by a multitracer technique. Komatsuna, Brassica rapa var. perviridis, was hydroponically cultivated in a nutrient solution containing a multitracer for 1 day. Nutrient concentration dependence of the selective absorption coefficient of various elements from Be to Re was obtained separately for leaves and roots. The selective absorption coefficients of these elements were, in general, found to decrease with an increase in the concentration of nutrient solutions. Regression equations of the power function for the selective absorption coefficients and the concentration of nutrient solutions were obtained for the leaves and roots. The effects of photon flux and growth stage of plants on the selective absorption coefficients were also studied. It was found that the photon flux influenced the accumulation of radionuclides in the roots but had no significant effect on the selective absorption coefficients for the leaves in 1-day cultivation with the multitracer. The selective absorption coefficients of Mn and Zn in the leaves of the plants at the development stage were higher than those at the maturation stage. For the other elements, no significant effects of the growth stage on the selective absorption coefficients were observed. (author)

  2. Revisiting Absorptive Capacity

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...... processes, with emphasis on exploitative learning. Before concluding, the paper addresses implications for theory and practice and limitations of this study....

  3. ANALGESIC ACTIVITY OF ROOT EXTRACT OF SOLANUM MELONGENA LINN ROOT

    Srivastava Ashish; Sanjay Yadav

    2011-01-01

    The present study was aimed at Pharmacognostic study and biological evaluation of analgesic activity of plants roots. The roots of plants were studies for Pharmacognostic characteristics namely, morphology, microscopy, physicochemical parameters, which can be of utilized in identification/authentication of the plant and/or its roots in crude drug form. The preliminary phytochemical screening of the dry residue was carried out by the chemical test and thin layer chromatographic method. The p...

  4. Perennial roots to immortality.

    Munné-Bosch, Sergi

    2014-10-01

    Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation. PMID:24563283

  5. Absorption Spectra of Astaxanthin Aggregates

    Olsina, Jan; Durchan, Milan; Minofar, Babak; Polivka, Tomas; Mancal, Tomas

    2012-01-01

    Carotenoids in hydrated polar solvents form aggregates characterized by dramatic changes in their absorption spectra with respect to monomers. Here we analyze absorption spectra of aggregates of the carotenoid astaxanthin in hydrated dimethylsulfoxide. Depending on water content, two types of aggregates were produced: H-aggregates with absorption maximum around 390 nm, and J-aggregates with red-shifted absorption band peaking at wavelengths >550 nm. The large shifts with respect to absorption...

  6. Removal of root filling materials.

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  7. ROOT Tutorial for Summer Students

    CERN. Geneva; Piparo, Danilo

    2015-01-01

    ROOT is a "batteries-included" tool kit for data analysis, storage and visualization. It is widely used in High Energy Physics and other disciplines such as Biology, Finance and Astrophysics. This event is an introductory tutorial to ROOT and comprises a front lecture and hands on exercises. IMPORTANT NOTE: The tutorial is based on ROOT 6.04 and NOT on the ROOT5 series.  IMPORTANT NOTE: if you have ROOT 6.04 installed on your laptop, you will not need to install any virtual machine. The instructions showing how to install the virtual machine on which you can find ROOT 6.04 can be found under "Material" on this page.

  8. Speciation of uranium in plants upon root accumulation and root-to-shoot translocation: A XAS and TEM study

    Uranium mobilization in surface waters and soils is highly dependent on its speciation. Links between U speciation and in plants mobility remain unclear, although understanding this relationship is essential in a view to properly develop efficient phyto remediation strategies. To address this question, we used X-ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) to determine U speciation and distribution in plant roots and leaves when exposed to U in the form of different chemical species. Our results indicate that U complexation with endogenous phosphate residues leads to its precipitation and fixation in plant organs, avoiding translocation from roots to leaves. We also show that complexation with a strong ligand such as citrate in exposure solution circumvents this precipitation, and enhances root-to-shoot translocation, in a U-carboxylate complex form. These results highlight correlations between U speciation in the environment and its mobility pattern in plants, which would help for phyto remediation purposes. (authors)

  9. Chemical Absorption Materials

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  10. Two-Phonon Absorption

    Hamilton, M. W.

    2007-01-01

    A nonlinear aspect of the acousto-optic interaction that is analogous to multi-photon absorption is discussed. An experiment is described in which the second-order acousto-optically scattered intensity is measured and found to scale with the square of the acoustic intensity. This experiment using a commercially available acousto-optic modulator is…

  11. Chemical Absorption Materials

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...... are mentioned. References to review papers, papers with experimental data, and papers describing the thermodynamic modelling of the systems are given....

  12. Absorption driven focus shift

    Harrop, N.; Wolf, S.; Maerten, O.; Dudek, K.; Ballach, S.; Kramer, R.

    2016-03-01

    Modern high brilliance near infrared lasers have seen a tremendous growth in applications throughout the world. Increased productivity has been achieved by higher laser power and increased brilliance of lasers. Positive impacts on the performance and costs of parts are opposed to threats on process stability and quality, namely shift of focus position over time. A high initial process quality will be reduced by contamination of optics, eventually leading to a focus shift or even destruction of the optics. Focus analysis at full power of multi-kilowatt high brilliance lasers is a very demanding task because of high power densities in the spot and the high power load on optical elements. With the newly developed high power projection optics, the High-Power Micro-Spot Monitor High Brilliance (HP-MSM-HB) is able to measure focus diameter as low as 20 μm at power levels up to 10 kW at very low internal focus shift. A main driving factor behind thermally induced focus shift is the absorption level of the optical element. A newly developed measuring system is designed to determine the relative absorption level in reference to a gold standard. Test results presented show a direct correlation between absorption levels and focus shift. The ability to determine the absorption level of optical elements as well as their performance at full processing power before they are put to use, enables a high level of quality assurance for optics manufacturers and processing head manufacturers alike.

  13. ZINC ABSORPTION BY INFANTS

    Zinc is a vital mineral in human nutrition, and rare cases of overt zinc deficiency are well described in term and preterm infants. A variety of methods have been developed to assess zinc absorption, retention, and balance in humans, either using mass (metabolic) balance or stable isotope-based METH...

  14. Facilitative root interactions in intercrops

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more...

  15. CRECIMIENTO, ABSORCIÓN DE FÓSFORO Y MORFOLOGÍA DE LA RAÍZ EN ESPÁRRAGOS INOCULADOS CON HONGOS MICORRIZALES Y PSEUDOMONAS FLUORESCENTES GROWTH, PHOSPHORUS ABSORPTION AND ROOT MORPHOLOGY OF ASPARAGUS INOCCULATED WITH MYCORRHIZAL FUNGI AND FLUORESCENT PSEUDOMONAS

    Juan Carlos Pérez Naranjo

    2004-12-01

    Full Text Available En un experimento bajo invernadero se evaluaron los efectos de la aplicación de fósforo (P y la inoculación con Glomus fistulosum y Pseudomonas aeruginosa sobre el crecimiento, la longitud de la raíz y la absorción de P por plantas de espárrago sembradas en un Alic Melanudand. La inoculación con G. fistulosum incrementó significativamente la masa seca de la parte aérea y de raíces, la longitud de raíces primarias y secundarias y la absorción de P por las plantas. La aplicación de P aumentó significativamente el P disponible en el suelo (Bray II; sin embargo, a pesar de tal incremento no hubo aumento significativo del crecimiento de las plantas. La inoculación con P. aeruginosa no tuvo efecto significativo sobre las variables estudiadas, ni se encontraron interacciones significativas entre los factores.A greenhouse experiment evaluated the effects of phosphorus (P application and inoculation with Glomus fistulosum and Pseudomonas aeruginosa on growth, root length, and P uptake of Asparagus officinalis grown on Alic Melanudand. Inoculation with G. fistulosum significantly increased shoot and root dry weight, primary and secondary root lengths, and plant P uptake. Phosphorus application significantly increased extractable P in the soil (Bray II, but despite this increase, there was no significant increase in plant growth. Inoculation with P. aeruginosa had no significant effect on the variables studied, nor were there significant interactions among the factors.

  16. Root system in declining forests

    Meyer, F.H.

    1987-07-11

    Trees with obligate ectomycorrhiza are more sensitive to environmental stress than those without ectomycorrhiza or with facultative ectomycorrhiza. With spruce seedlings growing in humus material from a declining spruce forest an experimental proof was given, that reduction of the mineral nitrogen content by adding sawdust to the rooting substrate increases the share of root tips converted to ectomycorrhizas. A close correlation has been found between the mycorrhiza frequency and the number of root tips. This means, that the ramification of a root system is the more intense the better the conditions for mycorrhizal development are.

  17. On roots of Dehn twists

    Monden, Naoyuki

    2009-01-01

    Margalit and Schleimer constructed nontrivial roots of the Dehn twist about a nonseparating curve. We prove that the conjugacy classes of roots of the Dehn twist about a nonseparating curve correspond to the conjugacy classes of periodic maps with certain conditions. Futhermore, we give data set which determine the conjugacy class of a root. As a consequence, we can find the minimum degree and the maximum degree, and show that the degree must be odd. Also, we give Dehn twist expression of the root of degree 3.

  18. Feynman Diagrams and Rooted Maps

    Prunotto, A; Czerski, P

    2013-01-01

    The {\\em Rooted Maps Theory}, a branch of the Theory of Homology, is shown to be a powerful tool for investigating the topological properties of Feynman diagrams, related to the single particle propagator in the quantum many-body systems. The numerical correspondence between the number of this class of Feynman diagrams as a function of perturbative order and the number of rooted maps as a function of the number of edges is studied. A graphical procedure to associate Feynman diagrams and rooted maps is then stated. Finally, starting from rooted maps principles, an original definition of the {\\em genus of a Feynman diagram}, which totally differs from the usual one, is given.

  19. Study on the dynamics in absorption of 32P by hybrid wheat at elongate stage

    The dynamics of absorbing 32P of hybrid wheat at elongate stage is studied under pot culture conditions. The results show that the absorption capacity of hybrid wheat to 32P is in agreement with regression equation. The increased extent of absorption for them is greater than that for parent with time, and the reduction rate of absorption is lower than the parent significantly. Their root activity is much higher than that of the parent, too. The overall heterotic vigor of hybrid wheat on the absorption capacity to 32P is the sum of that of all organs

  20. Root cause analysis

    This article provides some fundamental techniques of evaluating human performance and equipment related events which are in use in Krsko NPP. Before the large industrial accidents the human factor was considered as very reliable and was not accepted as a possible source of errors. Today it is evident that safety is a proper combination of factors associated with people, technology and organization. Determining the cause of equipment failures is a much more enjoyable, exercise than doing the same for human errors. People are emotional: they can be angry, scared, defensive, not trustful. Because of all that the determination of causes for human errors is much more difficult.In many cases the definition of human factors relates to operators as the source of the human errors. Such an approach restricts the search for the true root cause of an event. In reality the human factor is associated with operators as well as with managers, designers, instructors, maintenance people etc. Operating experience and in-depth analysis with the resulting lessons learnt are all evidence of the relevance of human errors for safety. The nuclear power plant industry has estimated the risk due to human errors closing to 70%. It is therefore obvious that sophisticated techniques are needed to focus on human errors. The root cause analysis in NPP Krsko is based on the following methods: Event and Causal Factor Charting, Change Analysis, Barrier Analysis, MORT (Management Oversight and Risk Tree Analysis) and Human Performance Evaluation. Event and casual Factor Charting is used for investigation of complex problems which need to be visualized in the form of a chart so as to provide a better understanding of the chronology of an event. Change Analysis is usually used for a particular problem with the equipment failure by using key questions: what?, when?, where?, who? and how? to find a final answer to the question WHY something happened. Barrier Analysis is used for procedural and

  1. Relationship among root characteristics and differential potassium uptake and use efficiency of selected cotton genotypes under potassium deficiency stress

    Potassium (K) uptake and K use efficiency are the most important characters of plant genotypes that determine their biomass production under K deficiency stress. This study reports the influence of some important root characters on the K uptake and use efficiency of three pre-selected cotton genotypes under K deficiency stress. These genotypes included CIM-506, NIAB-78 and NIBGE-2, selected on the basis of their differential K use efficiency i.e., low, medium and high, respectively. Cotton genotypes significantly (p<0.01) differed for their K use efficiency, K uptake of shoot, root and on total basis, tap-root length, lateral root number and specific K absorption rate based on tap root length. While, K accumulation rate, K translocation efficiency, K transport rate and specific K absorption rate based on root dry weight were non-significant. The genotype NIBGE-2 was the most tolerant genotype to K deficiency stress and performed best for all the parameters studied followed by NIAB-78 and CIM-506. A significant correlation was observed between K use efficiency and K uptake of cotton genotypes. The root characteristics viz., tap root length, lateral root number, K accumulation rate and specific K absorption rate directly influence both K uptake and use efficiency of cotton under deficient K condition. K translocation rate and specific K absorption rate, based on root dry weight, directly influence total K uptake but not K use efficiency. These physio-morphological root traits of cotton are highly important while breeding for K-use-efficient cotton genotypes. (author)

  2. Effect of soil moisture deficit in the upper root zone on growth and yield of soybeans

    Anwar-ul-Haq; Brown, D.A.

    Soybean producers in Arkansas frequently are confronted with drought conditions which limit yields. These moisture deficit periods result in decreased water and nutrient absorption which adversely affects root growth and distribution within the soil profile, bloom set, and seed-pod retention. Producers have attempted to eliminate this problem by irrigation, by the use of drought tolerant cultivars, and by chiseling to provide for greater root penetration into the subsoil.

  3. Maximal rank root subsystems of hyperbolic root systems

    Tumarkin, P.

    2003-01-01

    A Kac-Moody algebra is called hyperbolic if it corresponds to a generalized Cartan matrix of hyperbolic type. We study root subsystems of root systems of hyperbolic algebras. In this paper, we classify maximal rank regular hyperbolic subalgebras of hyperbolic Kac-Moody algebras.

  4. Radiographing roots and shoots

    The effect of seed orientation on germination time and on shoot and root growth patterns is studied. Neutron radiography is used to observe the development of 4 types of plants, maize, greenpea, soya bean and padi. These plants were grown in varying orientations; sand sizes, sand thicknesses, and level of water content. Radiography of the seeds and plants were obtained for time exposure ranging from 3-12 hours and at reactor thermal power level, ranging from 500-750 kilowatts. Results obtained showed that seeds planted in varying orientations need different length of time for shoot emergence. Neutron radiography is now developed to other areas of non-industrial applications in Malaysia. (A.J.)

  5. Investigation of plant water relations with divided root systems of soybean.

    Michel, B E; Elsharkawi, H M

    1970-11-01

    Soybean (Glycine max) was grown with root systems divided between adjacent cartons containing nutrient solution or soil. By adding polyethylene glycol (Carbowax 6000) to reduce solute potential or withholding water to reduce soil matric potential until water absorption from that side stopped, the root xylem water potential could be ascertained. Carbowax appeared to increase root resistance. An imbalance technique is described with which soil moisture contents of adjacent containers were followed individually. The patterns of water absorption obtained following repeated additions of water or addition of CaCl(2) solutions to one side indicated soil hydraulic conductivity became limiting at a soil water potential of -2 bars. A high concentration of CaCl(2) added to one side greatly reduced transpiration and produced severe plant injury. With part of the root system developing in nutrient solution, growth of roots into and water absorption from soil were slow; however, reduction of solute potential in the solution side greatly increased water absorption from the soil side. PMID:16657537

  6. Compensatory Root Water Uptake of Overlapping Root Systems

    Agee, E.; Ivanov, V. Y.; He, L.; Bisht, G.; Shahbaz, P.; Fatichi, S.; Gough, C. M.; Couvreur, V.; Matheny, A. M.; Bohrer, G.

    2015-12-01

    Land-surface models use simplified representations of root water uptake based on biomass distributions and empirical functions that constrain water uptake during unfavorable soil moisture conditions. These models fail to capture the observed hydraulic plasticity that allows plants to regulate root hydraulic conductivity and zones of active uptake based on local gradients. Recent developments in root water uptake modeling have sought to increase its mechanistic representation by bridging the gap between physically based microscopic models and computationally feasible macroscopic approaches. It remains to be demonstrated whether bulk parameterization of microscale characteristics (e.g., root system morphology and root conductivity) can improve process representation at the ecosystem scale. We employ the Couvreur method of microscopic uptake to yield macroscopic representation in a coupled soil-root model. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model a one-hectare temperate forest stand under natural and synthetic climatic forcing. Our results show that as shallow soil layers dry, uptake at the tree and stand level shift to deeper soil layers, allowing the transpiration stream demanded by the atmosphere. We assess the potential capacity of the model to capture compensatory root water uptake. Further, the hydraulic plasticity of the root system is demonstrated by the quick response of uptake to rainfall pulses. These initial results indicate a promising direction for land surface models in which significant three-dimensional information from large root systems can be feasibly integrated into the forest scale simulations of root water uptake.

  7. Absorptive Capacity and Diversity

    Kristinsson, Kári

    One of the most influential contributions to neo-Schumpeterian economics is Cohen and Levinthal‘s papers on absorptive capacity. Since their publication in the late 1980s and early 1990s the concept absorptive capacity has had substantial impact on research in economics and management, including...... international business, organizational economics, strategic management, technology management and last but not least neo-Schumpeterian economics. The goal of this dissertation is to examine what many consider as neglected arguments from the work by Cohen and Levinthal and thereby illuminate an otherwise...... overlooked area of research. Although research based on Cohen and Levinthal‘s work has made considerable impact, there is scarcity of research on certain fundamental points argued by Cohen and Levinthal. Among these is the importance of employee diversity as well as the type and nature of interaction between...

  8. Quantum absorption refrigerator.

    Levy, Amikam; Kosloff, Ronnie

    2012-02-17

    A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold, and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified; the cooling power J(c) vanishes as J(c) ∝ T(c)(α), when T(c)→0, where α=d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath. PMID:22401189

  9. Properties of Estimated Characteristic Roots

    Nielsen, Bent; Nielsen, Heino Bohn

    Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...

  10. Tibial avulsion fracture of the posterior root of the medial meniscus in children

    Iversen, Jonas Vestergård; Krogsgaard, Michael Rindom

    2012-01-01

    Few reports have described avulsion fractures of the posterior root of the medial meniscus in skeletally immature patients. This lesion should not be overlooked as it damages the load absorptive (distributive) function of the meniscus, increasing the risk of cartilage degeneration. Two cases of...... displaced avulsion fractures of the posterior root of the medial meniscus in children are presented along with a concise report of the literature regarding avulsion fractures of the posterior root of the medial meniscus. Both avulsions were reattached arthroscopically by trans-tibial pull-out sutures with a...

  11. Medico-legal aspects of vertical root fractures in root filled teeth

    Rosen, E; Tsesis, I; Tamse, A;

    2012-01-01

    To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT).......To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT)....

  12. Converting Sabine absorption coefficients to random incidence absorption coefficients

    Jeong, Cheol-Ho

    2013-01-01

    Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a sample and non-uniform intensity in the reverberation chambers under test. In this study, conversion methods from Sabine absorption...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...

  13. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays)

    Chimungu, Joseph G.; Loades, Kenneth W.; Lynch, Jonathan P.

    2015-01-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength we...

  14. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  15. Nutritional regulation of root development.

    Ruiz Herrera, León Francisco; Shane, Michael W; López-Bucio, José

    2015-01-01

    Mineral nutrients such as nitrogen (N), phosphorus (P), and iron (Fe) are essential for plant growth, development, and reproduction. Adequate provision of nutrients via the root system impacts greatly on shoot biomass and plant productivity and is therefore of crucial importance for agriculture. Nutrients are taken up at the root surface in ionic form, which is mediated by specific transport proteins. Noteworthy, root tips are able to sense the local and internal concentrations of nutrients to adjust growth and developmental processes, and ultimately, to increase or decrease the exploratory capacity of the root system. Recently, important progress has been achieved in identifying the mechanisms of nutrient sensing in wild- and cultivated species, including Arabidopsis, bean, maize, rice, lupin as well as in members of the Proteaceae and Cyperaceae families, which develop highly sophisticated root clusters as adaptations to survive in soils with very low fertility. Major findings include identification of transporter proteins and transcription factors regulating nutrient sensing, miRNAs as mobile signals and peptides as repressors of lateral root development under heterogeneous nutrient supply. Understanding the roles played by N, P, and Fe in gene expression and biochemical characterization of proteins involved in root developmental responses to homogeneous or heterogeneous N and P sources has gained additional interest due to its potential for improving fertilizer acquisition efficiency in crops. PMID:25760021

  16. Absorption heat pumps

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  17. Pion absorption processes

    Proton and deuteron production from low-energy pion absorption in light nuclei leading to discrete and continuum states were measured. The LEP beam line at LAMPF was used with a stack of 8 intrinsic germanium crystals. The proton energy spectra are in general characterized by a broad bump at an energy approximately corresponding to π+d → pp reaction kinematics, suggestive of pion absorption on 2 nucleons. The energy-integrated cross-section for production of deuterons has an angular distribution similar to that for production of protons. The dependence of the total pion absorption cross-section on A is explained using a semi-classical model for pion transport in nuclei. The (π+,p) as well as (π+,d) reactions generally favor transitions involving larger angular momentum transfer to the residual nucleus when states of similar nuclear structure are considered. The low-energy excitation spectra from the (π+,p) reaction are similar to the spectra from (p,d) reaction on 12C and 13C. However, a calculation of the (π+,p) cross-section using the measured (p,d) reaction with the formulation of Wilkin to relate the two reactions is in moderate disagreement with the measured (π+,p) cross-sections. The excitation spectra from the (π+,p) reaction indicte the importance of two-step processes for the reaction. The (π+,d) reaction leading to the ground state of -- residual nucleus has been seen for 7Li, 12C, and 13C targets. The measured cross section for the 12C(π+,d)10C reaction to the 2+ state is much higher than that for the ground state. For the case of 18O, no counts were seen for excitation energy of +,d) reaction

  18. Absorption of selected radionuclides

    In October 1978, the Institut fuer Energie- und Umweltforschung Heidelberg e.V. published a contribution to part 26 of the model study of radio-ecology at Biblis under the title 'Estimation of the absorption of radionuclides from the gastrointestinal tract in the blood'. Using the example of this contribution, a critical analysis is made to show how a selection of the information contained in various scientific publications and other items of literature can give uncritical readers the impression that all statements made are scientifically well founded. (orig./HP)

  19. Scattering with absorptive interaction

    Cassing, W.; Stingl, M.; Weiguny, A.

    1982-07-01

    The S matrix for a wide class of complex and nonlocal potentials is studied, with special attention given to the motion of singularities in the complex k plane as a function of the imaginary coupling strength. Modifications of Levinson's theorem are obtained and discussed. Analytic approximations to the S matrix in the vicinity of narrow resonances are exhibited and compared to numerical results of resonating-group calculations. The problem of defining resonances in the case of complex interactions is discussed, making contact with the usual analysis of scattering in terms of Argand diagrams. NUCLEAR REACTIONS Scattering theory, S matrix for absorptive potentials.

  20. The Quantum Absorption Refrigerator

    Levy, Amikam

    2011-01-01

    A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power Jc vanishes as Jc proportional to Tc^{alpha}, when Tc approaches the absolute zero, where alpha = 2 for a bath with flat spectral density and alpha = 3 for an Ohmic spectral density.

  1. Effect of parameter choice in root water uptake models – the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

    Bechmann, M.; Schneider, C; Carminati, A.; Vetterlein, D.; Attinger, S.; Hildebrandt, A

    2014-01-01

    Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water...

  2. Comprehensive analysis of Panax ginseng root transcriptomes

    Jayakodi, Murukarthick; Lee, Sang-Choon; Lee, Yun Sun; Park, Hyun-Seung; Kim, Nam-Hoon; Jang, Woojong; Lee, Hyun Oh; Joh, Ho Jun; Yang, Tae-Jin

    2015-01-01

    Background Korean ginseng (Panax ginseng C.A. Meyer) is a highly effective medicinal plant containing ginsenosides with various pharmacological activities, whose roots are produced commercially for crude drugs. Results Here, we used the Illumina platform to generate over 232 million RNA sequencing reads from four root samples, including whole roots from one-year-old plants and three types of root tissue from six-year-old plants (i.e., main root bodies, rhizomes, and lateral roots). Through de...

  3. Geospatial Absorption and Regional Effects

    IOAN MAC

    2009-01-01

    Full Text Available The geospatial absorptions are characterized by a specific complexity both in content and in their phenomenological and spatial manifestation fields. Such processes are differentiated according to their specificity to pre-absorption, absorption or post-absorption. The mechanisms that contribute to absorption are extremely numerous: aggregation, extension, diffusion, substitution, resistivity (resilience, stratification, borrowings, etc. Between these mechanisms frequent relations are established determining an amplification of the process and of its regional effects. The installation of the geographic osmosis phenomenon in a given territory (a place for example leads to a homogenization of the geospatial state and to the installation of the regional homogeneity.

  4. INDUSTRIAL ENGINEERING : ROOTING FOR ROOTS, HANKERING FOR HEROES

    P.S. Kruger

    2012-01-01

    ENGLISH ABSTRACT: The “roots” of Industrial Engineering are certainly extensive, diverse and deep. Similarly, there are numerous historical “heroes” that made significant contributions to the development of the Industrial Engineering discipline. For the sake of argument, this article will assume that Industrial Engineering has at least two identifiable main roots, namely Determinism and Stochastism. The article attempts to trace the early history1 of the stochastic root which is very...

  5. Root pruning reduces root competition in living mulch cropping systems

    Båth, B.; Kristensen, Hanne Lakkenborg; Thorup-Kristensen, Kristian

    2009-01-01

    In intercropping systems with a cash crop and a living mulch intercrop, competition between the cash crop and the intercrop (the living mulch) often reduces the yield of the cash crop. This project investigated (1) the influence of root pruning of living mulches on aboveground biomass of white cabbage. Below-ground growth and competition were examined by measuring (2) root distribution in minirhizotrons and (3) uptake of 15N placed at different soil depths. Two field experiments were carried ...

  6. Hypocotyl adventitious root organogenesis differs from lateral root development

    Inge eVerstraeten

    2014-09-01

    Full Text Available Wound-induced adventitious root (AR formation is a requirement for plant survival upon root damage inflicted by pathogen attack, but also during the regeneration of plant stem cuttings for clonal propagation of elite plant varieties. Yet, adventitious rooting also takes place without wounding. This happens for example in etiolated Arabidopsis thaliana hypocotyls, in which AR initiate upon de-etiolation or in tomato seedlings, in which AR initiate upon flooding or high water availability. In the hypocotyl AR originate from a cell layer reminiscent to the pericycle in the primary root (PR and the initiated AR share histological and developmental characteristics with lateral roots (LR. In contrast to the PR however, the hypocotyl is a determinate structure with an established final number of cells. This points to differences between the induction of hypocotyl AR and LR on the PR, as the latter grows indeterminately. The induction of AR on the hypocotyl takes place in environmental conditions that differ from those that control LR formation. Hence, AR formation depends on differentially regulated gene products. Similarly to AR induction in stem cuttings, the capacity to induce hypocotyl AR is genotype-dependent and the plant growth regulator auxin is a key regulator controlling the rooting response. The hormones cytokinins, ethylene, jasmonic acid and strigolactones in general reduce the root-inducing capacity. The involvement of this many regulators indicates that a tight control and fine-tuning of the initiation and emergence of AR exists. Recently, several genetic factors, specific to hypocotyl adventitious rooting in Arabidopsis thaliana, have been uncovered. These factors reveal a dedicated signaling network that drives AR formation in the Arabidopsis hypocotyl. Here we provide an overview of the environmental and genetic factors controlling hypocotyl-born AR and we summarize how AR formation and the regulating factors of this organogenesis are

  7. Plant root-microbe communication in shaping root microbiomes

    Lareen, Andrew; Burton, Frances; Schäfer, Patrick

    2016-01-01

    A growing body of research is highlighting the impacts root-associated microbial communities can have on plant health and development. These impacts can include changes in yield quantity and quality, timing of key developmental stages and tolerance of biotic and abiotic stresses. With such a range of effects it is clear that understanding the factors that contribute to a plant-beneficial root microbiome may prove advantageous. Increasing demands for food by a growing human population increase...

  8. Towards a multidimensional root trait framework: a tree root review.

    Weemstra, Monique; Mommer, Liesje; Visser, Eric J W; van Ruijven, Jasper; Kuyper, Thomas W; Mohren, Godefridus M J; Sterck, Frank J

    2016-09-01

    Contents 1159 I. 1159 II. 1161 III. 1164 IV. 1166 1167 References 1167 SUMMARY: The search for a root economics spectrum (RES) has been sparked by recent interest in trait-based plant ecology. By analogy with the one-dimensional leaf economics spectrum (LES), fine-root traits are hypothesised to match leaf traits which are coordinated along one axis from resource acquisitive to conservative traits. However, our literature review and meta-level analysis reveal no consistent evidence of an RES mirroring an LES. Instead the RES appears to be multidimensional. We discuss three fundamental differences contributing to the discrepancy between these spectra. First, root traits are simultaneously constrained by various environmental drivers not necessarily related to resource uptake. Second, above- and belowground traits cannot be considered analogues, because they function differently and might not be related to resource uptake in a similar manner. Third, mycorrhizal interactions may offset selection for an RES. Understanding and explaining the belowground mechanisms and trade-offs that drive variation in root traits, resource acquisition and plant performance across species, thus requires a fundamentally different approach than applied aboveground. We therefore call for studies that can functionally incorporate the root traits involved in resource uptake, the complex soil environment and the various soil resource uptake mechanisms - particularly the mycorrhizal pathway - in a multidimensional root trait framework. PMID:27174359

  9. IAA transport in corn roots includes the root cap

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing 3H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 μ1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 μ1 of sorbitol or the Ca2+ chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap

  10. Absorption Spectra of Astaxanthin Aggregates

    Olsina, Jan; Minofar, Babak; Polivka, Tomas; Mancal, Tomas

    2012-01-01

    Carotenoids in hydrated polar solvents form aggregates characterized by dramatic changes in their absorption spectra with respect to monomers. Here we analyze absorption spectra of aggregates of the carotenoid astaxanthin in hydrated dimethylsulfoxide. Depending on water content, two types of aggregates were produced: H-aggregates with absorption maximum around 390 nm, and J-aggregates with red-shifted absorption band peaking at wavelengths >550 nm. The large shifts with respect to absorption maximum of monomeric astaxanthin (470-495 nm depending on solvent) are caused by excitonic interaction between aggregated molecules. We applied molecular dynamics simulations to elucidate structure of astaxanthin dimer in water, and the resulting structure was used as a basis for calculations of absorption spectra. Absorption spectra of astaxanthin aggregates in hydrated dimethylsulfoxide were calculated using molecular exciton model with the resonance interaction energy between astaxanthin monomers constrained by semi-e...

  11. Root hairs improve root penetration, root-soil contact, and phosphorus acquisition in soils of different strength.

    Haling, Rebecca E; Brown, Lawrie K; Bengough, A Glyn; Young, Iain M; Hallett, Paul D; White, Philip J; George, Timothy S

    2013-09-01

    Root hairs are a key trait for improving the acquisition of phosphorus (P) by plants. However, it is not known whether root hairs provide significant advantage for plant growth under combined soil stresses, particularly under conditions that are known to restrict root hair initiation or elongation (e.g. compacted or high-strength soils). To investigate this, the root growth and P uptake of root hair genotypes of barley, Hordeum vulgare L. (i.e. genotypes with and without root hairs), were assessed under combinations of P deficiency and high soil strength. Genotypes with root hairs were found to have an advantage for root penetration into high-strength layers relative to root hairless genotypes. In P-deficient soils, despite a 20% reduction in root hair length under high-strength conditions, genotypes with root hairs were also found to have an advantage for P uptake. However, in fertilized soils, root hairs conferred an advantage for P uptake in low-strength soil but not in high-strength soil. Improved root-soil contact, coupled with an increased supply of P to the root, may decrease the value of root hairs for P acquisition in high-strength, high-P soils. Nevertheless, this work demonstrates that root hairs are a valuable trait for plant growth and nutrient acquisition under combined soil stresses. Selecting plants with superior root hair traits is important for improving P uptake efficiency and hence the sustainability of agricultural systems. PMID:23861547

  12. The HI absorption 'Zoo'

    Gereb, K; Morganti, R; Oosterloo, T A

    2014-01-01

    We present an analysis of the HI absorption in a sample of 101 flux-selected radio AGN (S_1.4 GHz > 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). HI absorption is detected in 32 galaxies, showing a broad variety of widths, shapes and kinematical properties. We characterize the HI spectra of the individual detections using the busy function (Westmeier et al. 2014). With the goal of identifying different morphological structures of HI, we study the kinematical and radio source properties of the detections as function of their width. Narrow lines (FWHM = 500 km/s). These detections are good candidates for being HI outflows. The detection rate of HI outflows is 5 percent in the total radio AGN sample. This fraction represents a lower limit, however it could suggests that, if outflows are a characteristic phenomenon of all radio sources, they would have a short depletion timescale compared to the lifetime of the AGN. Blueshifted and broad/asymmetric lines are more often present among young...

  13. Roots of mappings from manifolds

    Brooks Robin

    2004-01-01

    Full Text Available Assume that is a proper map of a connected -manifold into a Hausdorff, connected, locally path-connected, and semilocally simply connected space , and has a neighborhood homeomorphic to Euclidean -space. The proper Nielsen number of at and the absolute degree of at are defined in this setting. The proper Nielsen number is shown to a lower bound on the number of roots at among all maps properly homotopic to , and the absolute degree is shown to be a lower bound among maps properly homotopic to and transverse to . When , these bounds are shown to be sharp. An example of a map meeting these conditions is given in which, in contrast to what is true when is a manifold, Nielsen root classes of the map have different multiplicities and essentialities, and the root Reidemeister number is strictly greater than the Nielsen root number, even when the latter is nonzero.

  14. Ultrasonic cleaning of root canals

    Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel

    2011-11-01

    A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.

  15. Root Patterns in Heterogeneous Soils

    Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

    2010-12-01

    Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the

  16. Root systems and generalized associahedra

    Fomin, Sergey; Reading, Nathan

    2005-01-01

    These lecture notes for the IAS/Park City Graduate Summer School in Geometric Combinatorics (July 2004) provide an overview of root systems, generalized associahedra, and the combinatorics of clusters. Lectures 1-2 cover classical material: root systems, finite reflection groups, and the Cartan-Killing classification. Lectures 3-4 provide an introduction to cluster algebras from a combinatorial perspective. Lecture 5 is devoted to related topics in enumerative combinatorics.

  17. Roots of unity in orders

    Lenstra Jr., H. W.; Silverberg, A.

    2015-01-01

    We give deterministic polynomial-time algorithms that, given an order, compute the primitive idempotents and determine a set of generators for the group of roots of unity in the order. Also, we show that the discrete logarithm problem in the group of roots of unity can be solved in polynomial time. As an auxiliary result, we solve the discrete logarithm problem for certain unit groups in finite rings. Our techniques, which are taken from commutative algebra, may have further potential in the ...

  18. Roots of Quaternion Standard Polynomials

    Chapman, Adam

    2011-01-01

    Here we present a reduction of any quaternion standard polynomial equation into an equation with two central variables and quaternion coefficients. If only pure imaginary roots are in demand, then the equation is with one central variable. As a result of this reduction we obtain formulas for the solutions of quadratic equations. Another result is a routine for analytically solving cubic quaternion equations assuming they have at least one pure imaginary root.

  19. Root hair mutants of barley

    Barley mutants without root hairs or with short or reduced root hairs were isolated among M2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M2 seeds were sown in the field the same day. Spikes, 4-6 per M1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

  20. Sabine absorption coefficients to random incidence absorption coefficients

    Jeong, Cheol-Ho

    2014-01-01

    Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a specimen and non-uniform intensity in the test chamber. In this study, several methods that convert Sabine absorption coefficients into...... random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...

  1. Diffuse interstellar absorption bands

    XIANG FuYuan; LIANG ShunLin; LI AiGen

    2009-01-01

    The diffuse interstellar bands (DIBs) are a large number of absorption bands that are superposed on the interstellar extinction curve and are of interstellar origin. Since the discovery of the first two DIBs in the 1920s, the exact nature of DIBs still remains unclear. This article reviews the history of the detec-tions of DIBs in the Milky Way and external galaxies, the major observational characteristics of DIBs, the correlations or anti-correlations among DIBs or between DIBs and other interstellar features (e.g. the prominent 2175 Angstrom extinction bump and the far-ultraviolet extinction rise), and the proposed candidate carriers. Whether they are also present in circumstellar environments is also discussed.

  2. The HI absorption "Zoo"

    Geréb, K.; Maccagni, F. M.; Morganti, R.; Oosterloo, T. A.

    2015-03-01

    We present an analysis of the H I 21 cm absorption in a sample of 101 flux-selected radio AGN (S1.4 GHz> 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). We detect H I absorption in 32 objects (30% of the sample). In a previous paper, we performed a spectral stacking analysis on the radio sources, while here we characterize the absorption spectra of the individual detections using the recently presented busy function. The H I absorption spectra show a broad variety of widths, shapes, and kinematical properties. The full width half maximum (FWHM) of the busy function fits of the detected H I lines lies in the range 32 km s-1 200 km s-1). We study the kinematical and radio source properties of each group, with the goal of identifying different morphological structures of H I. Narrow lines mostly lie at the systemic velocity and are likely produced by regularly rotating H I disks or gas clouds. More H I disks can be present among galaxies with lines of intermediate widths; however, the H I in these sources is more unsettled. We study the asymmetry parameter and blueshift/redshift distribution of the lines as a function of their width. We find a trend for which narrow profiles are also symmetric, while broad lines are the most asymmetric. Among the broadest lines, more lines appear blueshifted than redshifted, similarly to what was found by previous studies. Interestingly, symmetric broad lines are absent from the sample. We argue that if a profile is broad, it is also asymmetric and shifted relative to the systemic velocity because it is tracing unsettled H I gas. In particular, besides three of the broadest (up to FW20 = 825 km s-1) detections, which are associated with gas-rich mergers, we find three new cases of profiles with blueshifted broad wings (with FW20 ≳ 500 km s-1) in high radio power AGN. These detections are good candidates for being HI outflows. Together with the known cases of outflows already included in the sample (3C 293 and

  3. Plant root-microbe communication in shaping root microbiomes.

    Lareen, Andrew; Burton, Frances; Schäfer, Patrick

    2016-04-01

    A growing body of research is highlighting the impacts root-associated microbial communities can have on plant health and development. These impacts can include changes in yield quantity and quality, timing of key developmental stages and tolerance of biotic and abiotic stresses. With such a range of effects it is clear that understanding the factors that contribute to a plant-beneficial root microbiome may prove advantageous. Increasing demands for food by a growing human population increases the importance and urgency of understanding how microbiomes may be exploited to increase crop yields and reduce losses caused by disease. In addition, climate change effects may require novel approaches to overcoming abiotic stresses such as drought and salinity as well as new emerging diseases. This review discusses current knowledge on the formation and maintenance of root-associated microbial communities and plant-microbe interactions with a particular emphasis on the effect of microbe-microbe interactions on the shape of microbial communities at the root surface. Further, we discuss the potential for root microbiome modification to benefit agriculture and food production. PMID:26729479

  4. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster

    Danjon, Frédéric; Caplan, Joshua S.; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account ...

  5. Absorption intestinale des vitamines liposolubles

    Reboul Emmanuelle

    2011-03-01

    Full Text Available The molecular mechanisms of fat-soluble vitamin intestinal absorption remain partly unknown, despite the fact that a better understanding of this process would certainly allow to improve their bioavailability. If their digestion-absorption process follows the fate of lipids globally, the recent discovery of membranes proteins involved in their absorption questioned the established dogmas. These new data should be taken into account to avoid dietary or drug interactions that may limit some fatsoluble vitamin bioavailability.

  6. Absorption intestinale des vitamines liposolubles

    Reboul Emmanuelle

    2011-01-01

    The molecular mechanisms of fat-soluble vitamin intestinal absorption remain partly unknown, despite the fact that a better understanding of this process would certainly allow to improve their bioavailability. If their digestion-absorption process follows the fate of lipids globally, the recent discovery of membranes proteins involved in their absorption questioned the established dogmas. These new data should be taken into account to avoid dietary or drug interactions that may limit some fat...

  7. The absorption and transportation of ferric-salt in apple trees

    59Fe tracer technique was used to study the ferric-salt absorption, utilization and transportation in apple trees. The results indicated that absorption and utilization rate of ferric salt was 0.056%∼0.110% for roots and 30% for leaves, and that Fe is not easily to be transferred from one part to another. Fulvic acid iron had a better effect than ferrous sulfate. Ferric-salt absorption, utilization and transference were different among the cultivars. Intensive injections of ferrous salt into the apple trunks seemed to be more effective for correcting of chlorosis

  8. X-ray Absorption Spectroscopy

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  9. Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain

    Topa, M.A.

    1984-01-01

    Seedlings of pond, and loblolly pines were grown in a non-circulating, continuously-flowing solution culture under anaerobic (0.75 mg/1 O/sub 2/) conditions to determine the effects of anaerobiosis on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root was demonstrated via rhizosphere oxidation experiments using indigo-carmine dye solutions and polarography. Stem and root collar lenticels were found to be the major sites of atmospheric O/sub 2/ entry for submerged roots. Longitudinal and radial pathways for gas diffusion via intercellular spaces in the pericycle and ray parenchyma, respectively, were elucidated histologically. Lenticel and aerenchyma development, and rhizosphere oxidation in roots of anaerobically-grown sand pine seedlings were minimal. Elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term /sup 32/P uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass. Phosphorus absorption rates were negatively correlated with internal tissue phosphorus concentrations, and root and shoot biomass. 315 refs., 25 figs., 14 tabs.

  10. Minimal Nielsen Root Classes and Roots of Liftings

    Marcio Colombo Fenille

    2009-01-01

    Full Text Available Given a continuous map f:K→M from a 2-dimensional CW complex into a closed surface, the Nielsen root number N(f and the minimal number of roots μ(f of f satisfy N(f≤μ(f. But, there is a number μC(f associated to each Nielsen root class of f, and an important problem is to know when μ(f=μC(fN(f. In addition to investigate this problem, we determine a relationship between μ(f and μ(f˜, when f˜ is a lifting of f through a covering space, and we find a connection between this problems, with which we answer several questions related to them when the range of the maps is the projective plane.

  11. Advances in experimental methods for root system architecture and root development

    Jun-bang Wang; Xiu-juan Zhang; Chu Wu

    2015-01-01

    Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems, and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root resear-ches on root development and root system architecture, and summarized the advantages and shortages of these meth-ods. Based on the analyses, we proposed three new ways to more understand root processes: (1) new experimental materials for root development; (2) a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software, and automatic data transport devices; (3) new techniques used to analyze quantitatively functional roots.

  12. Radiopacity of root filling materials

    A method for measuring the radiopacity of root filling materials is described. Direct measurements were made of the optic density values of the materials in comparison with a standard curve relating optic density to the thickness of an aluminium step wedge exposed simultaneously. By proper selection of film and conditions for exposure and development, it was possible to obtain a near-linear standard curve which added to the safety and reproducibility of the method. The technique of radiographic assessment was modified from clinical procedures in evaluating the obturation in radiographs, and it was aimed at detecting slits or voids between the dental wall and the filling material. This radiographic assessment of potensial leakage was compared with actual in vitro lekage of dye (basic fuchsin) into the roots of filled teeth. The result of the investigation show that root filling materials display a very wide range of radiopacity, from less than 3 mm to more than 12 mm of aluminium. It also seem that tooth roots that appear to be well obturated by radiographic evaluation, stand a good chance of beeing resistant to leakage in vitro, and that the type of filling material rather than its radiographic appearance, determines the susceptibility of the filled tooth to leakage in vitro. As an appendix the report contains a survey of radiopaque additives in root filling materials

  13. Root status and future developments

    In this talk the authors review the major additions and improvements made to the ROOT system in the last 18 months and present their plans for future developments. The additions and improvements range from modifications to the I/O sub-system to allow users to save and restore objects of classes that have not been instrumented by special ROOT macros, to the addition of a geometry package designed for building, browsing, tracking and visualizing detector geometries. Other improvements include enhancements to the quick analysis sub-system (TTree::Draw()), the addition of classes that allow inter-file object references (TRef, TRefArray), better support for templates and STL classes, amelioration of the Automatic Script Compiler and the incorporation of new fitting and mathematical tools. Efforts have also been made to increase the modularity of the ROOT system with the introduction of more abstract interfaces and the development of a plug-in manager. In the near future, they intend to continue the development of PROOF and its interfacing with GRID environments. They plan on providing an interface between Geant3, Geant4 and Fluka and the new geometry package. The ROOT-GUI classes will finally be available on Windows and they plan to release a GUI inspector and builder. In the last year, ROOT has drawn the endorsement of additional experiments and institutions. It is now officially supported by CERN and used as key I/O component by the LCG project

  14. Role of Cytokinin and Auxin in Shaping Root Architecture: Regulating Vascular Differentiation, Lateral Root Initiation, Root Apical Dominance and Root Gravitropism

    Aloni, R; ALONI, E.; Langhans, M.; ULLRICH, C. I.

    2006-01-01

    • Background and Aims Development and architecture of plant roots are regulated by phytohormones. Cytokinin (CK), synthesized in the root cap, promotes cytokinesis, vascular cambium sensitivity, vascular differentiation and root apical dominance. Auxin (indole-3-acetic acid, IAA), produced in young shoot organs, promotes root development and induces vascular differentiation. Both IAA and CK regulate root gravitropism. The aims of this study were to analyse the hormonal mechanisms that induce ...

  15. Absorption of volatile ruthenium

    Phase equilibrium and mass transfer measurements for the absorption of ruthenium tetroxide (RuO4) in aqueous and nitric acid solutions have been completed. Low concentration phase equilibrium measurements confirm that the system obeys Henry's law across 4 orders of magnitude in concentration. Mass transfer measurements from turbulent gas flow indicate that the diffusivity of RuO4 in air may increase slightly as its concentration is reduced by 5-6 orders of magnitude. The reaction of RuO4 with nitrous acid and nitrites in solution results in precipitated or colloidal RuO2. Initial, immediate decomposition of ∼ 50% of the RuO4 occurs at RuO4: HNO2 mole ratios between 10:1 and 1:2, and does not vary systematically with mole ratio in this range. A mathematical model of the RuO4 decontamination performance of a packed bed scrubber has been developed, and validated experimentally with a laboratory QVF system. A survey of modelling approaches for predicting the ruthenium decontamination performance of off-gas condensers has been carried out. (author)

  16. Retention of Root Canal Posts

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other...... half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  17. Adventitious Roots and Secondary Metabolism

    Hosakatte Niranjana Murthy; Eun Joo Hahn; Kee Yoeup Paek

    2008-01-01

    Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.

  18. Phytases for improved iron absorption

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    Phytase enzymes present an alternative to iron supplements, because they have been shown to improve iron absorption by means of catalysing the degradation of a potent iron absorption inhibitor: phytic acid. Phytic acid is a hexaphosphate of inositol and is particularly prevalent in cereal grains...

  19. Multifunctional hybrids for electromagnetic absorption

    Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

  20. Hot tube atomic absorption spectrochemistry.

    Woodriff, R; Stone, R W

    1968-07-01

    A small, commercially available atomic absorption instrument is used with a heated graphite tube for the atomic absorption analysis of liquid and solid silver samples. Operating conditions of the furnace are described and a sensitivity of about 5 ng of silver is reported. PMID:20068797

  1. Efficient hydraulic properties of root systems

    Bechmann, Marcel; Schneider, Christoph; Carminati, Andrea; Hildebrandt, Anke

    2013-04-01

    Understanding the mechanisms of ecosystem root water uptake (RWU) is paramount for parameterizing hydrological models. With the increase in computational power it is possible to calculate RWU explicitly up to the single plant scale using physical models. However, application of these models for increasing our understanding of ecosystem root water uptake is hindered by the deficit in knowledge about the detailed hydraulic parameter distribution within root systems. However, those physical models may help us to identify efficient parameterizations and to describe the influence of these hydraulic parameters on RWU profiles. In this research, we investigated the combined influence of root hydraulic parameters and different root topologies on shaping efficient root water uptake. First, we use a conceptual model of simple branching structures to understand the influence of branching location and transitions in root hydraulic properties on the RWU patterns in typical sub root structures. Second, we apply a physical model called "aRoot" to test our conclusions on complex root system architectures of single plants. aRoot calculates the distribution of xylem potential within arbitrary root geometries to satisfy a given water demand depending on the available water in the soil. Redistribution of water within the bulk soil is calculated using the Richards equation. We analyzed results using a measure of uptake efficiency, which describes the effort necessary for transpiration. Simulations with the conceptual model showed that total transpiration in sub root structures is independent of root hydraulic properties over a wide range of hydraulic parameters. On the other hand efficiency of root water uptake depends crucially on distribution hydraulic parameters in line with root topology. At the same time, these parameters shape strongly the distribution of RWU along the roots, and its evolution in time, thus leading to variable individual root water uptake profiles. Calculating

  2. Sensitivity of the "Root Bundle Model" to root mechanical properties and root distribution: Implication for shallow landslide stability.

    Schwarz, Massimiliano; Giadrossich, Filippo; Cohen, Denis

    2015-04-01

    Root reinforcement is recognized as an important factor for shallow landslides stability. Due to the complexity of root reinforcement mechanisms and the heterogeneity of the root-soil system, the estimation of parameters used in root reinforcement models is difficult, time consuming, and often highly uncertain. For practical applications, it is necessary to focus on the estimation of the most relevant parameters. The objective of the present contribution is to review the state of the art in the development of root reinforcement models and to discuss the sensitivity of the "Root Bundle Model" (RBM) when considering the variability of root mechanical properties and the heterogeneity of root distributions. The RBM is a strain-step loading fiber bundle model extended to include the mechanical and geometrical properties of roots. The model allows the calculation of the force-displacement behavior of a root bundle. In view of new results of field pullout tests performed on coarse roots of spruce (Picea abies) and considering a consistent dataset of root distribution of alpine tree species, we quantify the sensitivity of the RBM and the uncertainty associated with the most important input parameters. Preliminary results show that the extrapolation of force-diameter values from incomplete datasets (i.e., when only small roots are tested and values for coarse roots are extrapolated) may result in considerable errors. In particular, in the case of distributions with root diameters larger than 5 mm, root reinforcement tends to be dominated by coarse roots and their mechanical properties need to be quantified. In addition to the results of the model sensitivity, we present a possible best-practice method for the quantification of root reinforcement in view of its application to slope stability calculations and implementations in numerical models.

  3. Detrending bootstrap unit root tests

    Smeekes, S.

    2009-01-01

    The role of detrending in bootstrap unit root tests is investigated. When bootstrapping, detrending must not only be done for the construction of the test statistic, but also in the first step of the bootstrap algorithm. It is argued that the two points should be treated separately. Asymptotic validity of sieve bootstrap ADF unit root tests is shown for test statistics based on full sample and recursive OLS and GLS detrending. It is also shown that the detrending method in the first step of t...

  4. New theories of root growth modelling

    Landl, Magdalena; Schnepf, Andrea; Vanderborght, Jan; Huber, Katrin; Javaux, Mathieu; Bengough, A. Glyn; Vereecken, Harry

    2016-04-01

    In dynamic root architecture models, root growth is represented by moving root tips whose line trajectory results in the creation of new root segments. Typically, the direction of root growth is calculated as the vector sum of various direction-affecting components. However, in our simulations this did not reproduce experimental observations of root growth in structured soil. We therefore developed a new approach to predict the root growth direction. In this approach we distinguish between, firstly, driving forces for root growth, i.e. the force exerted by the root which points in the direction of the previous root segment and gravitropism, and, secondly, the soil mechanical resistance to root growth or penetration resistance. The latter can be anisotropic, i.e. depending on the direction of growth, which leads to a difference between the direction of the driving force and the direction of the root tip movement. Anisotropy of penetration resistance can be caused either by microscale differences in soil structure or by macroscale features, including macropores. Anisotropy at the microscale is neglected in our model. To allow for this, we include a normally distributed random deflection angle α to the force which points in the direction of the previous root segment with zero mean and a standard deviation σ. The standard deviation σ is scaled, so that the deflection from the original root tip location does not depend on the spatial resolution of the root system model. Similarly to the water flow equation, the direction of the root tip movement corresponds to the water flux vector while the driving forces are related to the water potential gradient. The analogue of the hydraulic conductivity tensor is the root penetrability tensor. It is determined by the inverse of soil penetration resistance and describes the ease with which a root can penetrate the soil. By adapting the three dimensional soil and root water uptake model R-SWMS (Javaux et al., 2008) in this way

  5. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  6. Four cuspal maxillary second premolar with single root and three root canals: Case report.

    Bansal, Parul; Nikhil, Vineeta; Goyal, Ayush; Singh, Ritu

    2016-01-01

    Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps. PMID:27563190

  7. Comparative pharmacognostical variations in stem, true root and aerial root of Tinospora cordifolia willd

    Rohit Ajith Gokarn; Supriya Gokarn; Galib; Harisha, C. R.; Biswajyoti Patgiri

    2014-01-01

    Context: Amrita (Tinospora cordifolia Willd.) an often used perennial climber used in different clinical conditions and various researches are useful in understanding its potential, but comparative pharmacognostical study of stem, true root and aerial root is not available till date. Root of Amrita is often used in folklore medicine. As true root is not abundantly available, aerial roots may be considered in the place of true root. Objective: The present study was designed to evaluate the sim...

  8. Rhizoctonia root rot of lentil

    Rhizoctonia root rot is a soilborne disease of lentil caused by the fungal pathogen Rhizoctonia solani, and is favored by cool (11-19 C or 52 - 66 F) and wet soil conditions. The disease starts as reddish or dark brown lesions on lentil plants near the soil line, and develops into sunken lesions an...

  9. [Root arthrosis of the thumb].

    Hautefeuille, P; Duquesnoy, B

    1991-12-15

    Root arthrosis of the thumb results from a degenerative lesion of the trapezometacarpal joint. It is particularly frequent in menopausal women. The often prolonged pain it produces sometimes raises therapeutic problems. Treatment is always medical at first, but when it fails several surgical operations will ensure permanent painlessness. PMID:1808686

  10. Roots of mappings from manifolds

    Robin Brooks

    2004-12-01

    Full Text Available Assume that f:X→Y is a proper map of a connected n-manifold X into a Hausdorff, connected, locally path-connected, and semilocally simply connected space Y, and y0∈Y has a neighborhood homeomorphic to Euclidean n-space. The proper Nielsen number of f at y0 and the absolute degree of f at y0 are defined in this setting. The proper Nielsen number is shown to a lower bound on the number of roots at y0 among all maps properly homotopic to f, and the absolute degree is shown to be a lower bound among maps properly homotopic to f and transverse to y0. When n>2, these bounds are shown to be sharp. An example of a map meeting these conditions is given in which, in contrast to what is true when Y is a manifold, Nielsen root classes of the map have different multiplicities and essentialities, and the root Reidemeister number is strictly greater than the Nielsen root number, even when the latter is nonzero.

  11. Disease notes - Bacterial root rot

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  12. Contemporary root canal filling strategies

    A.T. Moinzadeh

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation proced

  13. Modeling the Influence of Vegetation Root Distribution for a Changed Climate

    Song, J.; Hatzis, J. J.

    2010-12-01

    Accurate modeling of the carbon and water budget requires a dynamic vegetation module that can link carbon and water belowground. Root distribution determines the capacity for water uptake and nutrient absorption. Vegetation development belowground in semi-arid regions can be especially sensitive to climate change due to its important role in vegetation survival. The authors have developed a fine root allocation scheme in response to the relative availabilities of soil water and nutrients. A global soil nitrogen and phosphorus data set has been interpolated spatially at each grid point and incorporated into the Community Land Model (CLM). For each plant functional type, its fine root carbon in each soil layer is updated with input from photosynthesis and output to respiration and turnover. The results show that the simulated root distribution is reasonable in comparison with the observed carbon distribution. Simulated fine root carbon will be shifted to the moist lower soil layers as climate becomes drier. Further,influences of the dynamic root distribution scheme to net primary productivity (NPP) and air temperature are evaluated for different climate periods (1990-2004 vs. 1950-1964), and are compared with the results using current static root schemes.

  14. Gastrointestinal citrate absorption in nephrolithiasis

    Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

  15. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  16. Effects of Rooting Substrates on In Vitro Rooting of Anthurium andraeanum L. cv. Avanti

    Wararat KEATMETHA

    2004-06-01

    Full Text Available A study was made of the effects of rooting substrates on in vitro rooting of Anthurium andraeanum L. cv. Avanti, orange flower. Initiation of root was attempted in several rooting substrates with modified ½ MS medium supplemented with 30 g/l sucrose. The cut end of the shoot was dipped in 2.5 g/l indole-3-butyric acid (IBA before insertion in substrates. After 4 weeks of culture, it was found that roots were markedly induced in 8 and 12 g/l agar with 86.67 and 73.33% in root induction rate, 14.62 and 12.41 mm in root length, with 3.54 and 3.91 roots in root number respectively. However, 93.33% of root induction rate with 3.00 roots, and 11.66 mm in root length were produced on medium containing 1.5 g/l phytagel while peat moss and vermiculite could induce rooting at 46.67% with 7.86 and 6.66 mm in length, with 1.00 and 1.86 roots respectively. Root could not be induced in sphagnum moss. Anatomical study of root showed no abnormality in all rooting substrates. The roots formed in high concentrations of agar at 12 and 16 g/l, 2.0 and 2.5 g/l phytagel, and peat moss were thicker than those formed in other rooting substrates. Especially, root formed in peat moss had the largest vascular diameter. However, roots formed in phytagel, peat moss, and vermiculite had more root hairs than those formed in agar substrate. Plantlets, rooted in peat moss and vermiculite, survived at 100% after acclimation in a mixture of soil and coconut husk.

  17. Secondary Metabolite Content in Roots and Callus of Paeonia Anomala L.

    A.A. ZARIPOVA

    2014-06-01

    Full Text Available Taking into account the fact that in the process of introduction in vitro culture the change of secondary metabolite content may take place we compared the chemical composition of plant material of wild-growing plants of Paeonia anomala introduced and produced using the methods of clonal micropropagation, callus tissue.The content of phenolic compounds, that is catechins and gallatos was compared. Paeoniflorin content was estimated by direct spectrophotometry of methanol extracts (λ = 231,7 nm, ε 1% 1 sm = 265.4. Integral characteristic of the obtained extracts was received by comparison of absorption spectra using spectrophotometer SP - 121 within wave diapason 300 - 460 nm.Light absorption curves of methanol extracts had two distinct peaks at λ = 232 nm and λ = 275 nm typical of paeoniflorin. Paeoniflorin content was 80 % higher in young peony roots than in control plant. This glycoside content in callus culture was 44 % higher than in wild-growing plant roots and 26 % lower than in plantlet roots.The use of ethanol as extragent showed a higher content of extracted substances in callus tissue. The comparison of the obtained spectra in the region corresponding to phenolic compound absorption shows the highest phenolic compound content in callus tissue and young plant roots. Judging by light absorption maximum it may be phenolic acids. The lowest phenolic compound content was determined in adult wild-growing plant roots, where a high phlobaphene content was visually observed.The conducted research confirms the fact that callus culture of Paeonia anomala L. is a perspective producer of monoterpene glycosides and phenolic compounds. Extracts from plantlets and callus culture exceed in biological active substance content rootstock extracts of open air plants.

  18. Measuring the efficacy of a root biobarrier with x-ray computed tomography

    Tollner, E.W.; Murphy, C.E. Jr. (Georgia Univ., Griffin, GA (USA). Dept. of Agricultural Engineering)

    1990-08-16

    X-ray computed tomography is a useful tool for investigating soil physical properties nondestructively. There is a need to develop proper calibration relationships between soil properties and the x-ray absorption coefficient. The objective of the work was to evaluate soil factors affecting the x-ray absorption coefficient. Based on a theoretical analysis, experimental data from five soils and on results of several other investigators, it was concluded that for many applications, one calibration relationship is applicable to a wide range of soils. The montmorillinitic clay used in the study required special handling due to the extreme shrinkage of this soil upon drying. Knowledge of chemical composition enables approximations but not exact predictions of the x-ray absorption coefficient. The results suggested some reasonable alternative to exhaustive calibration for each anticipated soil condition. Quantification of root activity in terms of root growth and indirectly through water uptake is necessary for understanding plant growth dynamics. X-ray computed tomography (CT) enables qualitative as well as two quantitative outputs, one of which can lead to conclusions regarding root activity. A greenhouse study involving soil columns (Lakeland sand, bulk density 1.4 Mg/m{sup 3}) planted to soybean, Bahiagras, and control (no vegetation) was conducted in 1989. A treflan based on chemical barrier was placed in half of the soil column of each species. The mean x-ray absorption correlated to water content. Results suggested that root presence can also be indirectly inferred based on water content drawn down during planned stress events. It was concluded that x-ray CT may have a niche in soil-water-plant relation studies, particularly when plant species have large roots. 35 refs., 13 figs., 8 tabs.

  19. The Arabidopsis thaliana CLAVATA3/EMBRYO-SURROUNDING REGION 26 (CLE26) peptide is able to alter root architecture of Solanum lycopersicum and Brassica napus.

    Czyzewicz, Nathan; De Smet, Ive

    2016-01-01

    Optimal development of root architecture is vital to the structure and nutrient absorption capabilities of any plant. We recently demonstrated that AtCLE26 regulates A. thaliana root architecture development, possibly by altering auxin distribution to the root apical meristem via inhibition of protophloem development. In addition, we showed that AtCLE26 application is able to induce a root architectural change in the monocots Brachypodium distachyon and Triticum aestivum. Here, we showed that application of the synthetic AtCLE26 peptide similarly affects other important agricultural species, such as Brassica napus and Solanum lycopersicum. PMID:26669515

  20. ANALGESIC ACTIVITY OF ROOT EXTRACT OF SOLANUM MELONGENA LINN ROOT

    Srivastava Ashish

    2011-05-01

    Full Text Available The present study was aimed at Pharmacognostic study and biological evaluation of analgesic activity of plants roots. The roots of plants were studies for Pharmacognostic characteristics namely, morphology, microscopy, physicochemical parameters, which can be of utilized in identification/authentication of the plant and/or its roots in crude drug form. The preliminary phytochemical screening of the dry residue was carried out by the chemical test and thin layer chromatographic method. The preliminary phytochemical screening of dry residue showed the presence of Saponins, Alkaloids, Glycoside, and Flavonoids in various extracts. However most of the medicinally potential phytoconstituents were present in methanolic and aqueous extracts. The Hydroalcoholic extract was selected for Biological screening due to high alcoholic-soluble extractive value, high yield of successive alcoholic extract and TLC results. The analgesic screening was done using Hot plate method, Tail immersion methods and acetic acid induced in rats and mice. Hydroalcoholic extract was administered orally at the acute doses of 200mg/kg and 400mg/kg b.w. Several activities on these doses have already been reported. Both the doses showed significant (p<0.05 analgesic activity.

  1. Inhibition of strigolactones promotes adventitious root formation.

    Rasmussen, Amanda; Beveridge, Christine A; Geelen, Danny

    2012-06-01

    Roots that form from non-root tissues (adventitious roots) are crucial for cutting propagation in the forestry and horticulture industries. Strigolactone has been demonstrated to be an important regulator of these roots in both Arabidopsis and pea using strigolactone deficient mutants and exogenous hormone applications. Strigolactones are produced from a carotenoid precursor which can be blocked using the widely available but broad terpenoid biosynthesis blocker, fluridone. We demonstrate here that fluridone can be used to promote adventitious rooting in the model species Pisum sativum (pea). In addition, in the garden species Plumbago auriculata and Jasminium polyanthum fluridone was equally as successful at promoting roots as a commercial rooting compound containing NAA and IBA. Our findings demonstrate that inhibition of strigolactone signaling has the potential to be used to improve adventitious rooting in commercially relevant species. PMID:22580687

  2. Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

    Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcollar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root + plaque' material in excess of 1000 mg kg-1, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcollar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. - Accumulation of metals with iron plaque on macrophyte roots in wetlands poses an ecotoxicological risk to certain herbivores

  3. Arsenic rich iron plaque on macrophyte roots - an ecotoxicological risk?

    Taggart, M.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom); Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain)], E-mail: mark.taggart@uclm.es; Mateo, R. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real (Spain); Charnock, J.M.; Bahrami, F. [Synchrotron Radiation Department, CCLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Green, A.J. [Department of Wetland Ecology, Estacion Biologica de Donana, CSIC, Pabellon del Peru, Avenida Maria Luisa s/n, 41013 Seville (Spain); Meharg, A.A. [School of Biological Sciences, University of Aberdeen, Cruickshank Bld, St Machar Drive, Aberdeen, AB24 3UU (United Kingdom)

    2009-03-15

    Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcollar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root + plaque' material in excess of 1000 mg kg{sup -1}, and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcollar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque. - Accumulation of metals with iron plaque on macrophyte roots in wetlands poses an ecotoxicological risk to certain herbivores.

  4. Reproducibility of The Random Incidence Absorption Coefficient Converted From the Sabine Absorption Coefficient

    Jeong, Cheol-Ho; Chang, Ji-ho

    2015-01-01

    Absorption coefficients measured in reverberation chambers, Sabine absorption coefficients, suffer from two major problems. Firstly, they sometimes exceed unity. Secondly, the reproducibility of the Sabine absorption coefficients is quite poor, meaning that the Sabine absorption coefficients vary...

  5. Rhizosphere biophysics and root water uptake

    Carminati, Andrea; Zarebanadkouki, Mohsen; Ahmed, Mutez A.; Passioura, John

    2016-04-01

    The flow of water into the roots and the (putative) presence of a large resistance at the root-soil interface have attracted the attention of plant and soil scientists for decades. Such resistance has been attributed to a partial contact between roots and soil, large gradients in soil matric potential around the roots, or accumulation of solutes at the root surface creating a negative osmotic potential. Our hypothesis is that roots are capable of altering the biophysical properties of the soil around the roots, the rhizosphere, facilitating root water uptake in dry soils. In particular, we expect that root hairs and mucilage optimally connect the roots to the soil maintaining the hydraulic continuity across the rhizosphere. Using a pressure chamber apparatus we measured the relation between transpiration rate and the water potential difference between soil and leaf xylem during drying cycles in barley mutants with and without root hairs. The samples were grown in well structured soils. At low soil moistures and high transpiration rates, large drops in water potential developed around the roots. These drops in water potential recovered very slowly, even after transpiration was severely decreased. The drops in water potential were much bigger in barley mutants without root hairs. These mutants failed to sustain high transpiration rates in dry conditions. To explain the nature of such drops in water potential across the rhizosphere we performed high resolution neutron tomography of the rhizosphere of the barleys with and without root hairs growing in the same soil described above. The tomograms suggested that the hydraulic contact between the soil structures was the highest resistance for the water flow in dry conditions. The tomograms also indicate that root hairs and mucilage improved the hydraulic contact between roots and soil structures. At high transpiration rates and low water contents, roots extracted water from the rhizosphere, while the bulk soil, due its

  6. EXERCISE ENHANCING CALCIUM ABSORPTION MECHANISM

    Muliani

    2013-01-01

    Calcium has important role in many biological processes therefore calcium homeostasis should be maintained. Imbalance in calcium homeostasis would affects the bone metabolism, neuromuscular function, blood coagulation, cell proliferation and signal transduction. Homeostasis of calcium is maintained by three major organs: gastrointestinal tract, bone and kidney. Intestinal calcium absorption is the sole mechanism to supply calcium to the body. Calcium absorption controlled by calcitropic hormo...

  7. Incomplete intestinal absorption of fructose.

    Kneepkens, C M; Vonk, R J; Fernandes, J.

    1984-01-01

    Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children ...

  8. Absorption Of Dietary Lipid Components

    Abdulkadir Hurşit

    2015-01-01

    Although the digestion and absorption of lipids that are necessary for the survival of living organisms are well known in general terms, nevertheless how different lipids to be digested, how it is distributed into the bloodstream, and how to be used by the cells, are unknown issues by most non specialist people. In recent years, knowledge of lipid digestion and absorption has expanded considerably. More insight has been gained in the mechanism of action of H + pump as a transport system in fa...

  9. Inhibition of strigolactones promotes adventitious root formation

    Rasmussen, Amanda; Beveridge, Christine A.; Geelen, Danny

    2012-01-01

    Roots that form from non-root tissues (adventitious roots) are crucial for cutting propagation in the forestry and horticulture industries. Strigolactone has been demonstrated to be an important regulator of these roots in both Arabidopsis and pea using strigolactone deficient mutants and exogenous hormone applications. Strigolactones are produced from a carotenoid precursor which can be blocked using the widely available but broad terpenoid biosynthesis blocker, fluridone. We demonstrate her...

  10. Maxillary First Molar with Two Root Canals

    2013-01-01

    Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Depar...

  11. Gaseous release of radioactive iodine from decaying plants. I. Release following foliar and root uptake

    Iodine uptake by plants is a significant link in the contamination of the food chain. Long half-live iodine was studied considering foliar and root uptake, loss by rain scavenging, residue decay or outgassing in order to assess two aspects of the problem: the importance of outgassing and the effect of the route of transfer on iodine losses. It appeared that iodine release was a function of the vegetal type, there were differences according to the pattern of absorption (via leaf or root) and the processes of iodine release were usually related to biochemical mechanisms

  12. A Novel Approach for Oral Delivery of Insulin via Desmodium gangeticum Aqueous Root Extract

    Kurian, GA; Seetharaman, AV; Subramanian, NR; Paddikkala, J.

    2010-01-01

    Many challenges are associated with the oral delivery of insulin, relating to the physical and chemical stability of the hormone, and its absorption and metabolism in the human body. The present study aims to demonstrate the oral delivery of insulin in both normal and steptozotocin (STZ)-induced diabetic rats with the help of the aqueous extract of Desmodium gangeticum (DG) root. Human insulin was mixed with the aqueous extract of DG root (0.1 mg/ml) with human insulin (40 IU/ml) in ratio 1:1...

  13. [Oat growth and cation absorption characteristics under salt and alkali stress].

    Fan, Yuan; Ren, Chang-Zhong; Li, Pin-Fang; Ren, Tu-Sheng

    2011-11-01

    This paper monitored the oat growth and cation absorption characteristics on a saline-alkali soil in the Baicheng region of Jilin Province under low, medium, and high levels of salt stress. No significant differences were observed in the shoot growth and yield components under the three levels of salt stress, but the root biomass and root/shoot ratio decreased significantly with increasing salt stress level. At maturing stage, the root/shoot ratio under medium and high salt stresses was 77.2% and 64.5% of that under low salt stress, respectively. Under the three levels of salt stress, the K+/Na+ and Ca2+/Na+ ratios in oat plant had significant differences at trefoil stage, but no significant differences at heading stage. With the increase of salt stress level, the cation absorption selectivity coefficient of oat at filling stage decreased significantly, but the transportation selectivity coefficient had no significant difference under the three levels of stress. It was concluded that oat could adapt to the salt and alkali stress of soda-alkaline soil to some extent, and the adaptation capability decreased with the increasing level of stress. The decrease of oat root biomass and the stronger ion selective absorption capacity at heading stage under salt and alkali stress could benefit the shoot growth and yield components of oat. PMID:22303664

  14. Automatic schema evolution in Root

    ROOT version 3 (spring 2001) supports automatic class schema evolution. In addition this version also produces files that are self-describing. This is achieved by storing in each file a record with the description of all the persistent classes in the file. Being self-describing guarantees that a file can always be read later, its structure browsed and objects inspected, also when the library with the compiled code of these classes is missing. The schema evolution mechanism supports the frequent case when multiple data sets generated with many different class versions must be analyzed in the same session. ROOT supports the automatic generation of C++ code describing the data objects in a file

  15. Automatic Schema Evolution in Root

    ReneBrun; FonsRademakers

    2001-01-01

    ROOT version 3(spring 2001) supports automatic class schema evolution.In addition this version also produces files that are self-describing.This is achieved by storing in each file a record with the description of all the persistent classes in the file.Being self-describing guarantees that a file can always be read later,its structure browsed and objects inspected.also when the library with the compiled code of these classes is missing The schema evolution mechanism supports the frequent case when multiple data sets generated with many different class versions must be analyzed in the same session.ROOT supports the automatic generation of C++ code describing the data objects in a file.

  16. Arbuscular mycorrhizal fungal colonization of Glycyrrhiza glabra roots enhances plant biomass, phosphorus uptake and concentration of root secondary metabolites

    HongLing LIU; Yong TAN; Monika NELL; Karin ZITTER-EGLSEER; Chris WAWSCRAH; Brigitte KOPP; ShaoMing WANG; Johannes NOVAK

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi penetrate the cortical cells of the roots of vascular plants, and are widely distributed in soil. The formation of these symbiotic bodies accelerates the absorption and utilization of min-eral elements, enhances plant resistance to stress, boosts the growth of plants, and increases the survival rate of transplanted seedlings. We studied the effects of various arbuscular mycorrhizae fungi on the growth and devel-opment of licorice (Glycyrrhiza glabra). Several species of AM, such as Glomus mosseae, Glomus intraradices, and a mixture of fungi (G. mosseae, G. intraradices, G. cladoideum, G. microagregatum, G. caledonium and G. etunica-tum) were used in our study. Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi, plant dry biomass, phosphorus concentration and concentration of secondary metabolites. We estab-lished two cloned strains of licorice, clone 3 (C3) and clone 6 (C6) to exclude the effect of genotypic variations. Our results showed that the AM fungi could in fact increase the leaf and root biomass, as well as the phosphorus con-centration in each clone. Furthermore, AM fungi significantly increased the yield of certain secondary metabolites in clone 3. Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants. There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.

  17. Evaluation of bacterial leakage of four root- end filling materials: Gray Pro Root MTA, White Pro Root MTA, Root MTA and Portland Cement (type I

    Zarabian M.

    2005-07-01

    Full Text Available Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA, Portland Cement (type I and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556. Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time of the four tested root- end filling materials (P=0.9958. Conclusion: Based on the results of this study, there were no significant differences in leakage among the four

  18. Contemporary root canal filling strategies

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation procedure. This alternative placement technique results in an increase and homogenization of the adhesion of the material to intraradicular dentin. Subsequent research should aim at developing sealers wi...

  19. Root finding with threshold circuits

    Jeřábek, Emil

    2012-01-01

    Roč. 462, Nov 30 (2012), s. 59-69. ISSN 0304-3975 R&D Projects: GA AV ČR IAA100190902; GA MŠk(CZ) 1M0545 Institutional support: RVO:67985840 Keywords : root finding * threshold circuit * power series Subject RIV: BA - General Mathematics Impact factor: 0.489, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304397512008006#

  20. Archimedes' calculations of square roots

    Davies, E B

    2011-01-01

    We reconsider Archimedes' evaluations of several square roots in 'Measurement of a Circle'. We show that several methods proposed over the last century or so for his evaluations fail one or more criteria of plausibility. We also provide internal evidence that he probably used an interpolation technique. The conclusions are relevant to the precise calculations by which he obtained upper and lower bounds on pi.

  1. Application of glutathione to roots selectively inhibits cadmium transport from roots to shoots in oilseed rape

    Nakamura, Shin-ichi

    2013-01-01

    Glutathione is a tripeptide involved in various aspects of plant metabolism. This study investigated the effects of the reduced form of glutathione (GSH) applied to specific organs (source leaves, sink leaves, and roots) on cadmium (Cd) distribution and behaviour in the roots of oilseed rape plants (Brassica napus) cultured hydroponically. The translocation ratio of Cd from roots to shoots was significantly lower in plants that had root treatment of GSH than in control plants. GSH applied to roots reduced the Cd concentration in the symplast sap of root cells and inhibited root-to-shoot Cd translocation via xylem vessels significantly. GSH applied to roots also activated Cd efflux from root cells to the hydroponic solution. Inhibition of root-to-shoot translocation of Cd was visualized, and the activation of Cd efflux from root cells was also shown by using a positron-emitting tracer imaging system (PETIS). This study investigated a similar inhibitory effect on root-to-shoot translocation of Cd by the oxidized form of glutathione, GSSG. Inhibition of Cd accumulation by GSH was abolished by a low-temperature treatment. Root cells of plants exposed to GSH in the root zone had less Cd available for xylem loading by actively excluding Cd from the roots. Consequently, root-to-shoot translocation of Cd was suppressed and Cd accumulation in the shoot decreased. PMID:23364937

  2. Comparative pharmacognostical variations in stem, true root and aerial root of Tinospora cordifolia willd

    Rohit Ajith Gokarn

    2014-01-01

    Full Text Available Context: Amrita (Tinospora cordifolia Willd. an often used perennial climber used in different clinical conditions and various researches are useful in understanding its potential, but comparative pharmacognostical study of stem, true root and aerial root is not available till date. Root of Amrita is often used in folklore medicine. As true root is not abundantly available, aerial roots may be considered in the place of true root. Objective: The present study was designed to evaluate the similarities between stem, true root, aerial root and to substantiate the use of aerial root in place of true root. Materials and Methods: Macroscopic, microscopic and histochemical study of fresh samples of stem, aerial root and true root of Amrita was carried out. Results: The distinctive character of stem shows dominant pericyclic fibre and pith. True root is devoid of pith where as aerial root has condensed pith consisting of lignified parenchyma. Conclusion: Specific individual characters of stem and true root and similar characters of aerial root were evident.

  3. Printing Values In Interactive ROOT

    Perovic, Boris

    2015-01-01

    This project report summarizes the work I have been performing during the past twelve weeks as a Summer Student intern working on ROOT project in the SFT group, PH department, under the supervision of Axel Naumann and Danilo Piparo. One of the widely requested features for ROOT was improved interactive shell experience as well as improved printing of object values. Solving this issue was the goal of this project. Primarily, we have enabled printing of the collections. Secondly, we have unified the printing interface, making it much more robust and extendible. Thirdly, we have implemented printing of nested collections in a flexible and user-friendly manner. Finally, we have added an interactive mode, allowing for paginated output. At the beginning of the report, ROOT is presented with examples of where it is used and how important it is. Then, the motivation behind the project is elaborated, by presenting the previous state of the software package and its potential for improvement. Further, the process in wh...

  4. ROOT Status and Future Developments

    Brun, R; Canal, P; Rademakers, Fons; Goto, Masaharu; Canal, Philippe; Brun, Rene

    2003-01-01

    In this talk we will review the major additions and improvements made to the ROOT system in the last 18 months and present our plans for future developments. The additons and improvements range from modifications to the I/O sub-system to allow users to save and restore objects of classes that have not been instrumented by special ROOT macros, to the addition of a geometry package designed for building, browsing, tracking and visualizing detector geometries. Other improvements include enhancements to the quick analysis sub-system (TTree::Draw()), the addition of classes that allow inter-file object references (TRef, TRefArray), better support for templated and STL classes, amelioration of the Automatic Script Compiler and the incorporation of new fitting and mathematical tools. Efforts have also been made to increase the modularity of the ROOT system with the introduction of more abstract interfaces and the development of a plug-in manager. In the near future, we intend to continue the development of PROOF and...

  5. Reconciling root plasticity and architectural ground rules in tree root growth models with voxel automata

    Mulia, Rachmat; Dupraz, Christian; van Noordwijk, Meine

    2010-01-01

    Dynamic models of tree root growth and function have to reconcile the architectural rules for coarse root topology with the dynamics of fine root growth (and decay) in order to predict the strategic plus opportunistic behaviour of a tree root system in a heterogeneous soil. We present an algorithm for a 3D model based on both local (soil voxel level) and global (tree level) controls of root growth, with development of structural roots as a consequence of fine root function, rather than as dri...

  6. Parametric modeling of root length density and root water uptake in unsaturated soil

    BESHARAT, Sina; NAZEMI, Amir Hossein; SADRADDINI, Ali Ashraf

    2010-01-01

    The problem of water movement through the root zone has attracted increasing interest during the last few decades. In this research, the spatial and temporal pattern of root water uptake in wetted soil was studied in the root zone of a 6-year-old apple tree. An important part of the root water uptake model is root length density, which was measured by sampling soil cores in one quarter of the root zone. The exponential model better described the observed apple root distribution. The measured ...

  7. A New Anatomically Based Nomenclature for the Roots and Root Canals—Part 1: Maxillary Molars

    Jojo Kottoor

    2012-01-01

    Full Text Available Numerous terminologies have been employed in the dental literature to describe the roots and root canal systems of maxillary molars. This multiplicity in naming of roots and canals makes the reader susceptible to misinterpretation and confusion. No consensus thus far has been arrived at for defining the names of roots and root canals in maxillary molars, including their various morphological aberrations. The anatomical relation of roots and their root canals were identified and were subsequently named based on definite sets of criteria. A new method for identification and naming of roots and root canal anatomy in maxillary molars, based on their root and canal relationship, was formulated and is presented in this paper. The nomenclature makes certain essential modifications to the traditional approach to accommodate naming of the various aberrations presented in the maxillary molars. A simple, yet extensive, nomenclature system has been proposed that appropriately names the internal and external morphology of maxillary molars.

  8. Asteroidal Quadruples in non Rooted Path Graphs

    Gutierrez Marisa

    2015-11-01

    Full Text Available A directed path graph is the intersection graph of a family of directed subpaths of a directed tree. A rooted path graph is the intersection graph of a family of directed subpaths of a rooted tree. Rooted path graphs are directed path graphs. Several characterizations are known for directed path graphs: one by forbidden induced subgraphs and one by forbidden asteroids. It is an open problem to find such characterizations for rooted path graphs. For this purpose, we are studying in this paper directed path graphs that are non rooted path graphs. We prove that such graphs always contain an asteroidal quadruple.

  9. Five Roots Pattern of Median Nerve Formation

    Konstantinos Natsis

    2016-04-01

    Full Text Available An unusual combination of median nerve’s variations has been encountered in a male cadaver during routine educational dissection. In particular, the median nerve was formed by five roots; three roots originated from the lateral cord of the brachial plexus joined individually the median nerve’s medial root. The latter (fourth root was united with the lateral (fifth root of the median nerve forming the median nerve distally in the upper arm and not the axilla as usually. In addition, the median nerve was situated medial to the brachial artery. We review comprehensively the relevant variants, their embryologic development and their potential clinical applications.

  10. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    Muralidhar Tummala; Veeramachaneni Chandrasekhar; A Shashi Rashmi; Kundabala, M; Vasudev Ballal

    2012-01-01

    Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Gro...

  11. Involvement of Arabidopsis thaliana phospholipase Dzeta2 in root hydrotropism through the suppression of root gravitropism.

    Taniguchi, Yukimi Y; Taniguchi, Masatoshi; Tsuge, Tomohiko; Oka, Atsuhiro; Aoyama, Takashi

    2010-01-01

    Root hydrotropism is the phenomenon of directional root growth toward moisture under water-deficient conditions. Although physiological and genetic studies have revealed the involvement of the root cap in the sensing of moisture gradients, and those of auxin and abscisic acid (ABA) in the signal transduction for asymmetric root elongation, the overall mechanism of root hydrotropism is still unclear. We found that the promoter activity of the Arabidopsis phospholipase Dzeta2 gene (PLDzeta2) wa...

  12. Fine-scale spatial structure of root-associated fungi within a single plant root system

    Thoen, Ella

    2014-01-01

    Ectomycorrhiza (ECM) is an ancient and prevalent symbiosis between plants and fungi, and is crucial for growth and survival for a number of plants. Host plants can form ECM with multiple fungi, yet little is known about the fine-scale structure of root associated fungi within single root systems. The motivation for this study was to increase our knowledge about the richness, diversity and spatial distribution of fungal root symbionts within single root systems. An entire root system of the EC...

  13. Optimal root arrangement of cereal crops

    Jung, Yeonsu; Park, Keunhwan; Kim, Ho-Young

    2015-11-01

    The plant root absorbs water from the soil and supplies it to the rest part of the plant. It consists of a number of root fibers, through whose surfaces water uptake occurs. There is an intriguing observation that for most of cereal crops such as maize and wheat, the volume density of root in the soil declines exponentially as a function of depth. To understand this empirical finding, we construct a theoretical model of root water uptake, where mass transfer into root surface is modeled just as heat flux around a fin. Agreement between the theoretically predicted optimal root distribution in vertical direction and biological data supports the hypothesis that the plant root has evolved to achieve the optimal water uptake in competition with neighbors. This study has practical implication in the agricultural industry as well as optimal design of water transport networks in both micro- and macroscales. Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826, Korea.

  14. Absorption and Metabolism of Xanthophylls

    Eiichi Kotake-Nara

    2011-06-01

    Full Text Available Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  15. Transcriptional profile of maize roots under acid soil growth

    Mattiello Lucia

    2010-09-01

    Full Text Available Abstract Background Aluminum (Al toxicity is one of the most important yield-limiting factors of many crops worldwide. The primary symptom of Al toxicity syndrome is the inhibition of root growth leading to poor water and nutrient absorption. Al tolerance has been extensively studied using hydroponic experiments. However, unlike soil conditions, this method does not address all of the components that are necessary for proper root growth and development. In the present study, we grew two maize genotypes with contrasting tolerance to Al in soil containing toxic levels of Al and then compared their transcriptomic responses. Results When grown in acid soil containing toxic levels of Al, the Al-sensitive genotype (S1587-17 showed greater root growth inhibition, more Al accumulation and more callose deposition in root tips than did the tolerant genotype (Cat100-6. Transcriptome profiling showed a higher number of genes differentially expressed in S1587-17 grown in acid soil, probably due to secondary effects of Al toxicity. Genes involved in the biosynthesis of organic acids, which are frequently associated with an Al tolerance response, were not differentially regulated in both genotypes after acid soil exposure. However, genes related to the biosynthesis of auxin, ethylene and lignin were up-regulated in the Al-sensitive genotype, indicating that these pathways might be associated with root growth inhibition. By comparing the two maize lines, we were able to discover genes up-regulated only in the Al-tolerant line that also presented higher absolute levels than those observed in the Al-sensitive line. These genes encoded a lipase hydrolase, a retinol dehydrogenase, a glycine-rich protein, a member of the WRKY transcriptional family and two unknown proteins. Conclusions This work provides the first characterization of the physiological and transcriptional responses of maize roots when grown in acid soil containing toxic levels of Al. The

  16. Effects of fine root length density and root biomass on soil preferential flow in forest ecosystems

    Yinghu Zhang

    2015-04-01

    Full Text Available Aim of study: The study was conducted to characterize the impacts of plant roots systems (e.g., root length density and root biomass on soil preferential flow in forest ecosystems. Area of study: The study was carried out in Jiufeng National Forest Park, Beijing, China. Material and methods: The flow patterns were measured by field dye tracing experiments. Different species (Sophora japonica Linn,Platycladus orientalis Franco, Quercus dentata Thunbwere quantified in two replicates, and 12 soil depth were applied. Plant roots were sampled in the sieving methods. Root length density and root biomass were measured by WinRHIZO. Dye coverage was implied in the image analysis, and maximum depth of dye infiltration by direct measurement. Main results: Root length density and root biomass decreased with the increasing distance from soil surface, and root length density was 81.6% higher in preferential pathways than in soil matrix, and 66.7% for root biomass with respect to all experimental plots. Plant roots were densely distributed in the upper soil layers. Dye coverage was almost 100% in the upper 5-10 cm, but then decreased rapidly with soil depth. Root length density and root biomass were different from species: Platycladus orientalis Franco > Quercus dentata Thunb > Sophora japonica Linn. Research highlights: The results indicated that fine roots systems had strong effects on soil preferential flow, particularly root channels enhancing nutrition transport across soil profiles in forest dynamics.

  17. [Extraction of plant root apoplast solution: a case study with polycyclic aromatic hydrocarbons].

    Zhu, Man-Dang; Du, Jiang-Xue; Yue, Le; Li, Jin-Feng; Yang, Qing-Qing; Lu, Shou-Kun; Zhan, Xin-Hua

    2015-02-01

    It is of great importance to investigate the extraction of polycyclic aromatic hydrocarbons (PAHs) in plant root apoplast solution for elucidating the mechanisms underlying root absorption and translocation of PAHs and their control. However, little information is available on the extraction of plant root apoplast solution to date. In this study, wheat was employed and phenanthrene was used as the representative of PAHs. Phenanthrene extracted from wheat root apoplast solution increased with increasing vaccum degree, vacuum time, centrifugal speed and centrifugal time. Glucose- 6-phosphate dehydrogenase (G6PGH) activity in wheat root apoplast solution was enhanced with increasing vacuum degree, vacuum time, centrifugal speed and centrifugal time. For the vacuum infiltration centrifugation extraction, the optimal vacuum degree was 70 kPa, the optimal vacuum time was 10 min, the optimal centrifugal speed was 3 068 r x min(-1), and the optimal centrifugal time was 15 min. Our results provide a more convenient and effective method for investigation on pollutant transport in plant root apoplast. PMID:26031101

  18. On the use of antibiotics to reduce rhizoplane microbial populations in root physiology and ecology investigations

    Smart, D. R.; Ferro, A.; Ritchie, K.; Bugbee, B. G.

    1995-01-01

    No straightforward method exists for separating the proportion of ion exchange and respiration due to rhizoplane microbial organisms from that of root ion exchange and respiration. We examined several antibiotics that might be used for the temporary elimination of rhizoplane bacteria from hydroponically grown wheat roots (Triticum aestivum cv. Veery 10). Each antibiotic was tested for herbicidal activity and plate counts were used to enumerate bacteria and evaluate antibiotic kinetics. Only lactam antibiotics (penicillins and cephalosporins) did not reduce wheat growth rates. Aminoglycosides, the pyrimidine trimethoprim, colistin and rifampicin reduced growth rates substantially. Antibiotics acted slowly, with maximum reductions in rhizoplane bacteria occurring after more than 48 h of exposure. Combinations of nonphytotoxic antibiotics reduced platable rhizoplane bacteria by as much as 98%; however, this was generally a reduction from about 10(9) to 10(6) colony forming units per gram of dry root mass, so that many viable bacteria remained on root surfaces. We present evidence which suggests that insufficient bacterial biomass exists on root surfaces of nonstressed plants grown under well-aerated conditions to quantitatively interfere with root nitrogen absorption measurements.

  19. Variation in root activity with season and soil moisture in coconut

    An experiment was conducted at the College of Horticulture, Vellanikkara to study the effect of season and soil moisture regime on the physiological activity of roots in coconut. The experiment has been laid out in CRD with two replications at two different depths (20 and 75 cm) and moisture regimes (irrigated and rain fed) round the year. The 32P uptake was higher during wet season as compared to dry season in monocrop of coconut. The absorption was more from the surface layers during wet season and roots explored deeper soil layers during dry season. Irrigation in general improved absorption of 32P in coconut and resulted in higher uptake from the surface soil compared to that under rainfed condition. (author)

  20. Absorption capacity and toxicity of paper points after sterilization

    Mirian Marubayashi Hidalgo

    2008-01-01

    Full Text Available Objective: To evaluate the influence of the sterilization process on paper cones as regards their absorption capacity, and consequently, root canal drying, in addition to the possible release of any antimicrobial or cytotoxic product. Methods: The cones used were of three of the brands found on the Brazilian market Dentsply (Dentsply Indústria e Comércio Ltda., Petrópolis, Brazil, Endopoints (Endopoints Indústria e Comércio Ltda., Paraíba do Sul, Brazil and Tanari (Tanari Industrial Ltda., São Paulo, Brazil. To evaluate the absorption capacity, the cones were submitted to four sterilization cycles, and the modified Holland technique was performed. The antimicrobial/cytotoxic capacity was verified by means of depositing the sterilized cones in Petri dishes containing Miller-Hinton Agar and Blood Agar, seeded with S.aureus and E. coli. Results: The Dentsply (Dentsply Indústria e Comércio Ltda., Petrópolis, Brazil and Tanari (Tanari Industrial Ltda., São Paulo, Brazilcones presented greater absorption after the first sterilization cycle, followed by a drop in the second and third cycles, and a new increase in the fourth cycle. For the Endopoints (Endopoints Indústria e Comércio Ltda., Paraíba do Sul, Brazil cones, the values were inverted, with a small drop in absorption after the first cycle, increase in the second and third cycles, and a new drop in the fourth cycle. None of the cones presented antimicrobial activity after the sterilization process. Conclusion: The sterilization process by damp heat does not alter the properties of absorption and there is no release of by-products from the tested paper cones.

  1. Absorption properties of identical atoms

    Sancho, Pedro, E-mail: psanchos@aemet.es

    2013-09-15

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions.

  2. Transdermic absorption of Melagenina II

    The transdermic absorption of Melagenina II (MII) was evaluated. MII was a labelled with 125I by the yodogen method and purified by column chromatography with Sephadex LH-20 in ethanol: water (7:3). In vitro absorption of (125I) - MII thought human skin was carried out in Keshary-Chien modified diffusion cells. Tape stripping method was applied after 24 hours to evaluate the accumulated activity in dermis and epidermis. In vivo assays were performed in Sprague Dawley rats to analyze absorption of MII until 24 hours after a single application and for five days a low penetrability of the drug while in vivo there were not found blood levels significantly greater than zero , nevertheless and important amount of radioactivity was found in feces and urine. The activity was concentrated mainly in the application site in both models

  3. Absorption characteristics of bacteriorhodopsin molecules

    H K T Kumar; K Appaji Gowda

    2000-03-01

    The bacteriorhodopsin molecule absorbs light and undergoes a series of structural transformation following a well-defined photocycle. The complex photocycle is transformed to an equivalent level diagram by considering the lifetime of the intermediate states. Assuming that only and states are appreciably populated at any instant of time, the level diagram is further simplified to two-level system. Based on the rate equations for two-level system, an analytic expression for the absorption coefficient of bacteriorhodopsin molecule is derived. It is applied to study the behaviour of absorption coefficient of bacteriorhodopsin film in the visible wavelength region of 514 nm. The dependence of absorption coefficient of bacteriorhodopsin film on the thickness of the film, total number density of active molecules and initial number density of molecules in -state is presented in the graphical form.

  4. Absorption of focused light by spherical plasmas

    For light focused on spherical plasmas, we obtain new results giving the power absorbed by inverse bremsstrahlung and resonance absorption as a function of the focusing scheme. For a given beam profile and lens, there is an optimum focus to maximize total absorption. Linearly polarized beams lead to asymmetric absorption. Good agreement with experimental absorption and scattered light data is obtained

  5. Solar powered absorption air conditioning

    Vardon, J. M.

    1980-04-01

    Artificial means of providing or removing heat from the building are discussed along with the problem of the appropriate building design and construction for a suitable heat climate inside the building. The use of a lithium bromide-water absorption chiller, powered by a hot water store heated by an array of stationary flat collectors, is analyzed. An iterative method of predicting the cooling output from a LiBr-water absorption refrigeration plant having variable heat input is described and a model allowing investigation of the performance of a solar collector and thermal storage system is developed.

  6. Absorption Efficiency of Receiving Antennas

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...... patterns. It can approach 100% as closely as desired, although in practice this may not be an attractive solution. An example with a small endfire array of dipoles shows an efficiency of 93%. Several examples of small conical horn antennas are also given, and they all have absorption efficiencies less than...

  7. Nitrate reductase and acid phosphatase activities as affected by inorganic phosphate in corn roots

    Marie Kummerova; Józef Buczek

    2014-01-01

    The deficieny of inorganic phosphate in nutrient solution reduces by about 50 per cent NO3- absorption in corn seedlings, it decreases both in vitro and in vivo nitrate reductase (NR) activity, as well the potential and actual NR level and has a very weak effect on NR induction. Acid phosphatases activities increase in corn roots when the plants are grown in nutrient solution without phosphorus. We suggest that inorganic phosphate is required mainly for maintenance of NR activity rather, than...

  8. Forgotten Relations: Revisiting Papergirl Vancouver’s Feminist and Social Practice Art Roots

    Leroux, Danielle

    2014-01-01

    Papergirl Vancouver is part of a global network of community art projects that redefine street and participatory art by combining philanthropy, bicycles, and the gifting of art. Papergirl is not alone in explicitly challenging the art market economy, but its simultaneous reaction against neoliberal and postfeminist discourses and absorption by them makes it the site of productive contradictions. Using interviews with participants and fieldwork, this thesis situates Papergirl’s roots in the Se...

  9. Xanthones from Garcinia propinqua Roots.

    Meesakul, Pornphimol; Pansanit, Acharavadee; Maneerat, Wisanu; Sripisut, Tawanun; Ritthiwigrom, Thunwadee; Machana, Theeraphan; Cheenpracha, Sarot; Laphookhieo, Surat

    2016-01-01

    Phytochemical investigation of Garcinia propinqua roots led to the isolation and identification of a new xanthone, doitunggarcinone D (1), together with 15 known compounds (2-16). Their structures were elucidated by intensive analysis of spectroscopic data. Compounds 3, 6, 7, 14, 15 and 16 exhibited strong antibacterial activity against Bacillus subtilis TISTR 088 with MIC values in the range of 1-4 µg/mL. Compounds 3, 7, 10 and 14 also showed good antibacterial activity against B. cereus TISTR 688 with MIC values ranging from 4-8 µg/mL. PMID:26996028

  10. Morphometric data of canine sacral nerve roots with reference to electrical sacral root stimulation.

    Rijkhoff, N J; Koldewijn, E L; d'Hollosy, W; Debruyne, F M; Wijkstra, H

    1996-01-01

    Experiments to investigate restoration of lower urinary tract control by electrical stimulation of the sacral nerve roots are mostly performed on dogs, yet little morphometric data (such as canine root and fiber diameter distributions) are available. The aim of this study was to acquire morphometric data of the intradural canine sacral dorsal and ventral roots (S1-S3). Cross-sections of sacral roots of two beagle dogs were analyzed using a light microscope and image processing software. The cross-sectional area of each root was measured. The diameters of the fibers and the axons in the cross-sections of the S2 and S3 roots were measured and used to construct nerve fiber diameter frequency distribution histograms. The results show a unimodal diameter distribution for the dorsal roots and a bimodal distribution for the ventral roots. In addition the average ratio g of the axon diameter to fiber diameter was calculated for each root. PMID:8732990