WorldWideScience

Sample records for cucurbit leaf crumple

  1. Confirmation of bean leaf beetle, Cerotoma trifurcata, feeding on cucurbits

    Directory of Open Access Journals (Sweden)

    R.L. Koch

    2004-02-01

    Full Text Available The objective of these studies was to assess the degree to which bean leaf beetle, Cerotoma trifurcata (Forster, will feed on cucurbits. In 2003, we documented an infestation of C. trifurcata in a commercial pumpkin field near Rosemount, MN, USA. To evaluate C. trifurcata feeding on cucurbits, we conducted laboratory no-choice and choice test feeding studies. In the laboratory, C. trifurcata fed most heavily on cotyledon-stage cucumber plants, followed by pumpkin and squash. With soybean plants present, C. trifurcata still fed on cucumber plants. However, C. trifurcata appeared to prefer soybeans until the quality of the soybean plants was diminished through feeding damage. This is the first known report of C. trifurcata feeding on cucurbits. The pest potential of C. trifurcata in cucurbit cropping systems should be further evaluated.

  2. Plant cells without detectable plastids are generated in the crumpled leaf mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Chen, Yuling; Asano, Tomoya; Fujiwara, Makoto T; Yoshida, Shigeo; Machida, Yasunori; Yoshioka, Yasushi

    2009-05-01

    Plastids are maintained in cells by proliferating prior to cell division and being partitioned to each daughter cell during cell division. It is unclear, however, whether cells without plastids are generated when plastid division is suppressed. The crumpled leaf (crl) mutant of Arabidopsis thaliana is a plastid division mutant that displays severe abnormalities in plastid division and plant development. We show that the crl mutant contains cells lacking detectable plastids; this situation probably results from an unequal partitioning of plastids to each daughter cell. Our results suggest that crl has a partial defect in plastid expansion, which is suggested to be important in the partitioning of plastids to daughter cells when plastid division is suppressed. The absence of cells without detectable plastids in the accumulation and replication of chloroplasts 6 (arc6) mutant, another plastid division mutant of A. thaliana having no significant defects in plant morphology, suggests that the generation of cells without detectable plastids is one of the causes of the developmental abnormalities seen in crl plants. We also demonstrate that plastids with trace or undetectable amounts of chlorophyll are generated from enlarged plastids by a non-binary fission mode of plastid replication in both crl and arc6.

  3. Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant

    KAUST Repository

    Hudik, Elodie

    2014-07-18

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants.

  4. Differential Cotton leaf crumple virus-VIGS-mediated gene silencing and viral genome localization in different Gossypium hirsutum genetic backgrounds

    KAUST Repository

    Idris, Ali

    2010-12-01

    A Cotton leaf crumple virus (CLCrV)-based gene silencing vector containing a fragment of the Gossypium hirsutum Magnesium chelatase subunit I was used to establish endogenous gene silencing in cotton of varied genetic backgrounds. Biolistic inoculation resulted in systemic and persistent photo-bleaching of the leaves and bolls of the seven cultivars tested, however, the intensity of silencing was variable. CLCrV-VIGS-mediated expression of green fluorescent protein was used to monitor the in planta distribution of the vector, indicating successful phloem invasion in all cultivars tested. Acala SJ-1, one of the cotton cultivars, was identified as a particularly optimal candidate for CLCrV-VIGS-based cotton reverse-genetics. © 2010 Elsevier Ltd.

  5. Contribuição das folhas cotiledonares para o crescimento e estabelecimento de plântulas de cucurbitáceas Cotyledonary leaf contribution for growth and establishment of cucurbit seedlings

    Directory of Open Access Journals (Sweden)

    Dilson Antônio Bisognin

    2004-06-01

    seedlings (with intact cotyledons. Initial growth was quantified at 3-day intervals, from emergence until 21 DAE, by assessing expansion rate of cotyledonary leaves, time from emergence to achieve equivalence between leaf and cotyledonary area, and total dry matter production. Squash showed the highest expansion rate of cotyledonary leaves, the shortest time to achieve equivalence between leaf and cotyledonary area, and the highest total dry matter production. Squash and cucumber seedlings showed higher dependence on cotyledonary leaves than watermelon and bottlegourd. Impairment of cotyledonary leaves, depending on species, cotiledon damage level and seedling physiological age, can drastically affect initial growth and establishment of seedlings, therefore leading to yield reductions in cucurbits.

  6. Plastic deformation of 2D crumpled wires

    International Nuclear Information System (INIS)

    Gomes, M A F; Donato, C C; Brito, V P; Coelho, A S O

    2008-01-01

    When a single long piece of elastic wire is injected through channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper this packing process is investigated but using plastic wires which give rise to completely irreversible structures of different morphology. In particular, the plastic deformation from circular to oblate configurations of crumpled wires is experimentally studied, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility and very large deformations, scaling is still observed.

  7. Differential Colonization Dynamics of Cucurbit Hosts by Erwinia tracheiphila.

    Science.gov (United States)

    Vrisman, Cláudio M; Deblais, Loïc; Rajashekara, Gireesh; Miller, Sally A

    2016-07-01

    Bacterial wilt is one of the most destructive diseases of cucurbits in the Midwestern and Northeastern United States. Although the disease has been studied since 1900, host colonization dynamics remain unclear. Cucumis- and Cucurbita-derived strains exhibit host preference for the cucurbit genus from which they were isolated. We constructed a bioluminescent strain of Erwinia tracheiphila (TedCu10-BL#9) and colonization of different cucurbit hosts was monitored. At the second-true-leaf stage, Cucumis melo plants were inoculated with TedCu10-BL#9 via wounded leaves, stems, and roots. Daily monitoring of colonization showed bioluminescent bacteria in the inoculated leaf and petiole beginning 1 day postinoculation (DPI). The bacteria spread to roots via the stem by 2 DPI, reached the plant extremities 4 DPI, and the plant wilted 6 DPI. However, Cucurbita plants inoculated with TedCu10-BL#9 did not wilt, even at 35 DPI. Bioluminescent bacteria were detected 6 DPI in the main stem of squash and pumpkin plants, which harbored approximately 10(4) and 10(1) CFU/g, respectively, of TedCu10-BL#9 without symptoms. Although significantly less systemic plant colonization was observed in nonpreferred host Cucurbita plants compared with preferred hosts, the mechanism of tolerance of Cucurbita plants to E. tracheiphila strains from Cucumis remains unknown.

  8. Cultivation and uses of cucurbits

    Science.gov (United States)

    Cultivated cucurbits have spread through trade and exploration from their respective Old and New World centers of origin to the six arable continents and are important in local, regional and world trade. Cucumber (Cucumis sativus L.), melon (Cucumis melo L.), pumpkin, squash and gourd (Cucurbita spp...

  9. Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

    Science.gov (United States)

    Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

    2014-10-01

    Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g-1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance.

  10. Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

    Science.gov (United States)

    Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

    2014-01-01

    Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretchable and high-performance electrodes for supercapacitors based on new crumpled-graphene papers. Electrolyte-mediated-graphene paper bonded on a compliant substrate can be crumpled into self-organized patterns by harnessing mechanical instabilities in the graphene paper. As the substrate is stretched, the crumpled patterns unfold, maintaining high reliability of the graphene paper under multiple cycles of large deformation. Supercapacitor electrodes based on the crumpled graphene papers exhibit a unique combination of high stretchability (e.g., linear strain ~300%, areal strain ~800%), high electrochemical performance (e.g., specific capacitance ~196 F g−1), and high reliability (e.g., over 1000 stretch/relax cycles). An all-solid-state supercapacitor capable of large deformation is further fabricated to demonstrate practical applications of the crumpled-graphene-paper electrodes. Our method and design open a wide range of opportunities for manufacturing future energy-storage devices with desired deformability together with high performance. PMID:25270673

  11. Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

    Science.gov (United States)

    Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

    2017-01-11

    Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

  12. Understanding crumpling lipid vesicles at the gel phase transition

    Science.gov (United States)

    Hirst, Linda; Ossowski, Adam; Fraser, Matthew

    2011-03-01

    Wrinkling and crumpling transitions in different membrane types have been studied extensively in recent years both theoretically and computationally. There has also been very interesting recent work on defects in liquid crystalline shells. Lipid bilayer vesicles, widely used in biophysical research can be considered as a single layer smectic shell in the liquid crystalline phase. On cooling the lipid vesicle a transition to the gel phase may take place in which the lipid chains tilt and assume a more ordered packing arrangement. We observe large scale morphological changes in vesicles close to this transition point using fluorescence microscopy and investigate the possible mechanisms for this transition. Confocal microscopy is used to map 3D vesicle shape and crumpling length-scales. We also employ the molecular tilt sensitive dye, Laurdan to investigate the role of tilt domain formation on macroscopic structure. Funded by NSF CAREER award (DMR - BMAT #0852791).

  13. Crumpling of graphene oxide through evaporative confinement in nanodroplets produced by electrohydrodynamic aerosolization

    Energy Technology Data Exchange (ETDEWEB)

    Kavadiya, Shalinee; Raliya, Ramesh; Schrock, Michael; Biswas, Pratim, E-mail: pbiswas@wustl.edu [Washington University in St. Louis, Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering (United States)

    2017-02-15

    Restacking of graphene oxide (GO) nanosheets results in loss of surface area and creates limitations in its widespread use for applications. Previously, two-dimensional (2D) GO sheets have been crumpled into 3D structures to prevent restacking using different techniques. However, synthesis of nanometer size crumpled graphene particles and their direct deposition onto a substrate have not been demonstrated under room temperature condition so far. In this work, the evaporative crumpling of GO sheets into very small size (<100 nm) crumpled structures using an electrohydrodynamic atomization technique is described. Systematic study of the effect of different electrohydrodynamic atomization parameters, such as (1) substrate-to-needle distance, (2) GO concentration in the precursor solution, and (3) flow rate (droplet size) on the GO crumpling, is explored. Crumpled GO (CGO) particles are characterized online using a scanning mobility particle sizer (SMPS) and off-line using electron microscopy. The relation between the confinement force and the factors affecting the crumpled structure is established. Furthermore, to expand the application horizons of the structure, crumpled GO–TiO{sub 2} nanocomposites are synthesized. The method described here allows a simple and controlled production of graphene-based particles/composites with direct deposition onto any kind of substrate for a variety of applications.

  14. Crumple zone design for pedestrian protection using impact analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Hyung Il; Jeon, Young Eun; Kim, Dae Young; Kim, Heon Young [Kangwon National Univ., Chuncheon si (Korea, Republic of); Kim, Yong Soo [Product Development Team, Gyeongsan si (Korea, Republic of)

    2012-08-15

    This paper describes the design process for an automobile crumple zone for pedestrian protection. The impact load and bending moments predicted by impact analysis were used to design a plastic structure that may help reduce pedestrian injuries to the thigh area. The fracture effect was incorporated into the model by calculating the damage to the plastic material during impact, and the analysis was conducted under the European New Car Assessment Program (Euro NCAP) test conditions, using the upper legform developed by ESI Corporation. In addition, the values predicted by the analysis were validated by comparison with results of actual impact tests.

  15. Crumple zone design for pedestrian protection using impact analysis

    International Nuclear Information System (INIS)

    Moon, Hyung Il; Jeon, Young Eun; Kim, Dae Young; Kim, Heon Young; Kim, Yong Soo

    2012-01-01

    This paper describes the design process for an automobile crumple zone for pedestrian protection. The impact load and bending moments predicted by impact analysis were used to design a plastic structure that may help reduce pedestrian injuries to the thigh area. The fracture effect was incorporated into the model by calculating the damage to the plastic material during impact, and the analysis was conducted under the European New Car Assessment Program (Euro NCAP) test conditions, using the upper legform developed by ESI Corporation. In addition, the values predicted by the analysis were validated by comparison with results of actual impact tests

  16. Cucurbits [Cucumber, melon, pumpkin and squash

    Science.gov (United States)

    The focus of this chapter is on the edible members of the Cucurbitaceae family. The three important food-grade cucurbit genera Citrullus, Cucumis, and Cucurbita include the species Citrullus lanatus watermelons), Cucumis melo (cantaloupes and other sweet melons), Cucumis sativa (cucumbers and pick...

  17. Highly crumpled solar reduced graphene oxide electrode for supercapacitor application

    Science.gov (United States)

    Mohanapriya, K.; Ahirrao, Dinesh J.; Jha, Neetu

    2018-04-01

    Highly crumpled solar reduced graphene oxide (CSRGO) was synthesized by simple and rapid method through freezing the solar reduced graphene oxide aqueous suspension using liquid nitrogen and used as electrode material for supercapacitor application. This electrode material was characterized by transmission electron microscope (TEM), X-Ray diffractometer (XRD) and Raman Spectroscopy techniques to understand the morphology and structure. The electrochemical performance was studied by cyclic voltammetry (CV), galvanostatic charge/discharge (CD) and electrochemical impedance spectroscopy (EIS) using 6M KOH electrolyte. The CSRGO exhibit high specifc capacitance of 210.1 F g-1 at the current density of 0.5 A g-1 and shows excellent rate capability. These features make the CSRGO material as promising electrode for high-performance supercapacitors.

  18. Self-dispersed crumpled graphene balls in oil for friction and wear reduction.

    Science.gov (United States)

    Dou, Xuan; Koltonow, Andrew R; He, Xingliang; Jang, Hee Dong; Wang, Qian; Chung, Yip-Wah; Huang, Jiaxing

    2016-02-09

    Ultrafine particles are often used as lubricant additives because they are capable of entering tribological contacts to reduce friction and protect surfaces from wear. They tend to be more stable than molecular additives under high thermal and mechanical stresses during rubbing. It is highly desirable for these particles to remain well dispersed in oil without relying on molecular ligands. Borrowing from the analogy that pieces of paper that are crumpled do not readily stick to each other (unlike flat sheets), we expect that ultrafine particles resembling miniaturized crumpled paper balls should self-disperse in oil and could act like nanoscale ball bearings to reduce friction and wear. Here we report the use of crumpled graphene balls as a high-performance additive that can significantly improve the lubrication properties of polyalphaolefin base oil. The tribological performance of crumpled graphene balls is only weakly dependent on their concentration in oil and readily exceeds that of other carbon additives such as graphite, reduced graphene oxide, and carbon black. Notably, polyalphaolefin base oil with only 0.01-0.1 wt % of crumpled graphene balls outperforms a fully formulated commercial lubricant in terms of friction and wear reduction.

  19. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Science.gov (United States)

    Khalaf, Eman M.; Raizada, Manish N.

    2018-01-01

    The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays) against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanideratum). The endophytes were also assayed in planta (leaf disk and detached leaf bioassays) for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs) known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR) proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169) exhibited antagonism to the five phytopathogens, of which 68% (50/73) of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169) of endophytes emitted host defense inducing VOCs (acetoin/diacetyl) and 62% (104/169) secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated cucurbits

  20. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Directory of Open Access Journals (Sweden)

    Eman M. Khalaf

    2018-02-01

    Full Text Available The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanideratum. The endophytes were also assayed in planta (leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169 exhibited antagonism to the five phytopathogens, of which 68% (50/73 of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169 of endophytes emitted host defense inducing VOCs (acetoin/diacetyl and 62% (104/169 secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated

  1. Bacterial Seed Endophytes of Domesticated Cucurbits Antagonize Fungal and Oomycete Pathogens Including Powdery Mildew

    Directory of Open Access Journals (Sweden)

    Eman M. Khalaf

    2018-02-01

    Full Text Available The cucurbit vegetables, including cucumbers, melons and pumpkins, have been cultivated for thousands of years without fungicides. However, their seed germination stage is prone to be infected by soil-borne fungal and oomycete pathogens. Endophytes are symbionts that reside inside plant tissues including seeds. Seed endophytes are founders of the juvenile plant microbiome and can promote host defense at seed germination and later stages. We previously isolated 169 bacterial endophytes associated with seeds of diverse cultivated cucurbits. We hypothesized that these endophytes can antagonize major fungal and oomycete pathogens. Here we tested the endophytes for in vitro antagonism (dual culture assays against important soil-borne pathogens (Rhizoctonia solani, Fusarium graminearum, Phytophthora capsici, Pythium aphanidermatum. The endophytes were also assayed in planta (leaf disk and detached leaf bioassays for antagonism against a foliar pathogen of global importance, Podosphaera fuliginea, the causative agent of cucurbit powdery mildew. The endophytes were further tested in vitro for secretion of volatile organic compounds (VOCs known to induce plant defense. Extracellular ribonuclease activity was also tested, as a subset of pathogenesis-related (PR proteins of plant hosts implicated in suppression of fungal pathogens, displays ribonuclease activity. An unexpected majority of the endophytes (70%, 118/169 exhibited antagonism to the five phytopathogens, of which 68% (50/73 of in vitro antagonists belong to the genera Bacillus and Paenibacillus. All Lactococcus and Pantoea endophytes exhibited anti-oomycete activity. However, amongst the most effective inoculants against Podosphaera fuliginea were Pediococcus and Pantoea endophytes. Interestingly, 67% (113/169 of endophytes emitted host defense inducing VOCs (acetoin/diacetyl and 62% (104/169 secreted extracellular ribonucleases in vitro, respectively. These results show that seeds of cultivated

  2. Microscopically crumpled indium-tin-oxide thin films as compliant electrodes with tunable transmittance

    International Nuclear Information System (INIS)

    Ong, Hui-Yng; Shrestha, Milan; Lau, Gih-Keong

    2015-01-01

    Indium-tin-oxide (ITO) thin films are perceived to be stiff and brittle. This letter reports that crumpled ITO thin films on adhesive poly-acrylate dielectric elastomer can make compliant electrodes, sustaining compression of up to 25% × 25% equi-biaxial strain and unfolding. Its optical transmittance reduces with crumpling, but restored with unfolding. A dielectric elastomer actuator (DEA) using the 14.2% × 14.2% initially crumpled ITO thin-film electrodes is electrically activated to produce a 37% areal strain. Such electric unfolding turns the translucent DEA to be transparent, with transmittance increased from 39.14% to 52.08%. This transmittance tunability promises to make a low-cost smart privacy window

  3. Microscopically crumpled indium-tin-oxide thin films as compliant electrodes with tunable transmittance

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Hui-Yng [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore); School of Engineering, Nanyang Polytechnic, Singapore 569830 (Singapore); Shrestha, Milan; Lau, Gih-Keong, E-mail: mgklau@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2015-09-28

    Indium-tin-oxide (ITO) thin films are perceived to be stiff and brittle. This letter reports that crumpled ITO thin films on adhesive poly-acrylate dielectric elastomer can make compliant electrodes, sustaining compression of up to 25% × 25% equi-biaxial strain and unfolding. Its optical transmittance reduces with crumpling, but restored with unfolding. A dielectric elastomer actuator (DEA) using the 14.2% × 14.2% initially crumpled ITO thin-film electrodes is electrically activated to produce a 37% areal strain. Such electric unfolding turns the translucent DEA to be transparent, with transmittance increased from 39.14% to 52.08%. This transmittance tunability promises to make a low-cost smart privacy window.

  4. Quantum statistical mechanics of nonrelativistic membranes: crumpling transition at finite temperature

    Science.gov (United States)

    Borelli, M. E. S.; Kleinert, H.; Schakel, Adriaan M. J.

    2000-03-01

    The effect of quantum fluctuations on a nearly flat, nonrelativistic two-dimensional membrane with extrinsic curvature stiffness and tension is investigated. The renormalization group analysis is carried out in first-order perturbative theory. In contrast to thermal fluctuations, which soften the membrane at large scales and turn it into a crumpled surface, quantum fluctuations are found to stiffen the membrane, so that it exhibits a Hausdorff dimension equal to two. The large-scale behavior of the membrane is further studied at finite temperature, where a nontrivial fixed point is found, signaling a crumpling transition.

  5. Serological and molecular detection and prevalence of Cucurbit ...

    African Journals Online (AJOL)

    ajl2

    2012-08-21

    Aug 21, 2012 ... P. O. Box, 98616-93511, Agriculture and Natural Resources Research Center of Sistan Iran. E-mail: .... Nepal, Taiwan, China, Reunion Island, Swaziland, Brazil, .... A 10-year survey (1993–2002) of cucurbit viruses in Sudan.

  6. Analysis of an RNA-seq Strand-Specific Library from an East Timorese Cucumber Sample Reveals a Complete Cucurbit aphid-borne yellows virus Genome.

    Science.gov (United States)

    Maina, Solomon; Edwards, Owain R; de Almeida, Luis; Ximenes, Abel; Jones, Roger A C

    2017-05-11

    Analysis of an RNA-seq library from cucumber leaf RNA extracted from a fast technology for analysis of nucleic acids (FTA) card revealed the first complete genome of Cucurbit aphid-borne yellows virus (CABYV) from East Timor. We compare it with 35 complete CABYV genomes from other world regions. It most resembled the genome of the South Korean isolate HD118. Copyright © 2017 Maina et al.

  7. Bi-axially crumpled silver thin-film electrodes for dielectric elastomer actuators

    International Nuclear Information System (INIS)

    Low, Sze-Hsien; Lau, Gih-Keong

    2014-01-01

    Metal thin films, which have high conductivity, are much stiffer and may fracture at a much lower strain than dielectric elastomers. In order to fabricate compliant electrodes for use in dielectric elastomer actuators (DEAs), metal thin films have been formed into either zigzag patterns or corrugations, which favour bending and only allow uniaxial DEA deformations. However, biaxially compliant electrodes are desired in order to maximize generated forces of DEA. In this paper, we present crumpled metal thin-film electrodes that are biaxially compliant and have full area coverage over the dielectric elastomer. These crumpled metal thin-film electrodes are more stretchable than flat metal thin films; they remain conductive beyond 110% radial strain. Also, crumpling reduced the stiffening effect of metal thin films on the soft elastomer. As such, DEAs using crumpled metal thin-film electrodes managed to attain relatively high actuated area strains of up to 128% at 1.8 kV (102 Vμm −1 ). (paper)

  8. Survey on The Occurrence of Viruses Infecting Cucurbits in Yogyakarta and Central Java

    Directory of Open Access Journals (Sweden)

    Budi Setiadi Daryono

    2009-12-01

    Full Text Available Cucurbits are grown throughout the Java Island as dry season crops. Plants having mosaic, mottling, chlorosis and leaf distortion symptoms were frequently found in most of the cucurbit fields during the survey which conducted in Central Java including Sleman, Kulon Progo, and Klaten during July–September 2000 and 2001. Using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA; Cucumber mosaic virus (CMV, Cucumber green mottle mosaic virus (CGMMV and Kyuri green mottle mosaic virus (KGMMV were found infecting cucurbits. CMV was widespread, infecting 48.9% of the samples tested followed by CGMMV (12.8% and KGMMV (6.4%, while others samples (31.9% were not tested, double infections were common with 8.5 % of the samples being infected with two viruses (CGMMV and KGMMV and 34% with three viruses (CMV, CGMMV, and KGMMV. Severe mosaic and mottle symptoms were associated most often with single infection of CGMMV and KGMMV respectively. In addition, these are the first detections of CGMMV and KGMMV infecting cucurbit plants in Indonesia. Tanaman labu-labuan umumnya tumbuh sepanjang musim kemarau diPulau Jawa. Tanaman labu-labuan dengan gejala mosaik, klorosis, mottling dan bentuk daun serta buah yang berubah banyak dijumpai selama survei yang dilakukan di Kulon Progo, Sleman dan Klaten pada bulan Juli sampai September tahun 2000 dan 2001. Deteksi menggunakan metode double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA telah berhasil mengetahui keberadaan dan infeksiCucumber mosaic virus(CMV,Cucumber green mottle mosaic virus (CGMMV dan Kyuri green mottle mosaic virus (KGMMV pada tanaman labu-labuan di tiga kabupaten tersebut. CMV menginfeksi tanaman labu-labuan tinggi yaitu 48,9% dari jumlah sampel tanaman yang dikoleksi, kemudian CGMMV (12,8% dan KGMMV(6,4%, sedangkan sebanyak 14 sampel tanaman (31,9%tidak dideteksi.Infeksi ganda banyak ditemukan dan 8,5 % sampel tanaman terinfeksi oleh dua jenis virus (CGMMV dan

  9. Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant

    KAUST Repository

    Hudik, Elodie; Yoshioka, Yasushi; Domenichini, Sé Verine; Bourge, Mickaë l; Soubigout-Taconnat, Ludivine; Mazubert, Christelle; Yi, Dalong; Bujaldon, Sandrine; Hayashi, Hiroyuki; De Veylder, Lieven; Bergounioux, Catherine; Benhamed, Moussa; Raynaud, Cé cile

    2014-01-01

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles

  10. Bowel perforation by crumpled paper in a patient presenting with acute abdominal pain

    International Nuclear Information System (INIS)

    Bakhshaeekia, Alireza; Hosseini, Seyed M.V; Razmi, Tannaz; Shamsaeefar, Alireza

    2009-01-01

    Many of the abdominal foreign bodies are due to accidental ingestion. Our objective in this case report is to emphasize the importance of the enquiry about the foreign body in the differential diagnosis of acute abdominal pain. According to our knowledge, this is the first report of bowel perforation caused by paper ingestion. A 14-year-old boy with abdominal pain underwent exploratory laparotomy and was found to have abdominal pus and ileal perforation. A crumpled paper was found at the site of perforation. Postoperative enquiry revealed that the patient had ingested 10 crumpled papers. We highlight that recording the history is an important aspect in the management of patients with acute abdominal pain and that foreign bodies should be included in its differential diagnosis. (author)

  11. Cucurbits powdery mildew race identity and reaction of melon genotypes

    Science.gov (United States)

    Genetic resistance is one of the most suitable strategies to control cucurbit powdery mildew (CPM) on melon, incited by Podosphaera xanthii or Golovinomyces orontii. However, many races of these pathogens have been reported worldwide in recent years, what may compromise the effectiveness of this met...

  12. Serological and molecular detection and prevalence of Cucurbit ...

    African Journals Online (AJOL)

    During the 2009 growing seasons, virus-like symptoms were noticed on cucurbit crops (melons (Cucumis melo L.) and watermelons [Citrullus lanatus (Thunb.) Matsum and Nakai)] grown in the Sistan region. The symptoms were widespread and included initial chlorotic lesions followed by yellowing of whole leaves and ...

  13. Self-adaptive strain-relaxation optimization for high-energy lithium storage material through crumpling of graphene.

    Science.gov (United States)

    Zhao, Yunlong; Feng, Jiangang; Liu, Xue; Wang, Fengchao; Wang, Lifen; Shi, Changwei; Huang, Lei; Feng, Xi; Chen, Xiyuan; Xu, Lin; Yan, Mengyu; Zhang, Qingjie; Bai, Xuedong; Wu, Hengan; Mai, Liqiang

    2014-08-01

    High-energy lithium battery materials based on conversion/alloying reactions have tremendous potential applications in new generation energy storage devices. However, these applications are limited by inherent large volume variations and sluggish kinetics. Here we report a self-adaptive strain-relaxed electrode through crumpling of graphene to serve as high-stretchy protective shells on metal framework, to overcome these limitations. The graphene sheets are self-assembled and deeply crumpled into pinecone-like structure through a contraction-strain-driven crumpling method. The as-prepared electrode exhibits high specific capacity (2,165 mAh g(-1)), fast charge-discharge rate (20 A g(-1)) with no capacity fading in 1,000 cycles. This kind of crumpled graphene has self-adaptive behaviour of spontaneous unfolding-folding synchronized with cyclic expansion-contraction volumetric variation of core materials, which can release strain and maintain good electric contact simultaneously. It is expected that such findings will facilitate the applications of crumpled graphene and the self-adaptive materials.

  14. Characterization of Cucumber Mosaic Virus Originating from Cucurbits in Serbia

    Directory of Open Access Journals (Sweden)

    Ana Vučurović

    2011-01-01

    Full Text Available Cucumber mosaic virus (CMV is considered one of the most economically importantplant viruses and has a worldwide distribution and a very wide host range including plantsfrom family Cucurbitaceae. In Serbia, on cucurbits CMV was detected in single and mixedinfections with Zucchini yellow mosaic virus (ZYMV and Watermelon mosaic virus (WMV. Viruses,including CMV, are constantly present in cucurbit crops, but their frequency changesby year and locality. Surveys and sample collections were conducted in cucurbit crops inthe period from 2008 to 2009 at 15 localities in Vojvodina province, and sample testing wascarried out using the DAS-ELISA method and commercially available antisera for six economicallymost important cucurbit viruses. In 2008, a total of 51 samples were collected from13 cucurbit crops of oilseed pumpkin Olinka variety, squash, and bottle gourd and CMV wasdetected in a total of 55% of tested samples with symptoms of viral infection. The most commoninfectious type was mixed infection with ZYMV and WMV (35.3%, and then mixedinfection with ZYMV (17.7% and WMV (2%. A total of 599 symptomatic samples of oilseedpumpkin Olinka variety, zucchini squash varieties Beogradska and Tosca, squash, and wintersquash were collected in 15 cucurbits crops in 2009. CMV was present in 4.4% of totalcollected samples, in single infections in 1.3%, and in mixed with WMV or ZYMV in 1.3%, and1.8%. Five CMV isolates were obtained by mechanical inoculations of N. glutinosa and oneof them was selected for further biological characterization. Test plants which were describedto be hosts of CMV expressed symptoms characteristic for those caused by CMV afterinoculations by isolate 115-08. CMV specific primers Au1u/Au2d were used to amplify an850 bp fragment using RT-PCR method. Amplified fragment encodes the entire viral coatprotein (CP gene and partial 5’ and 3’ UTRs of two selected CMV isolates. Amplified fragmentswere sequenced and deposited in the NCBI, where

  15. Origin and evolution of cultivated cucurbits Origem e evolução de cucurbitáceas cultivadas

    Directory of Open Access Journals (Sweden)

    Dilson Antônio Bisognin

    2002-08-01

    Full Text Available Cucurbits (Cucurbitaceae are among the most important plant families supplying humans with edible products and useful fibers. Plants of this family are very similar in above ground development, but they have high genetic diversity for fruit shape and other fruit characteristics, resulting in a variety of uses. The objective of this review was to discuss the origin and evolution of the most important cultivated cucurbits. Understanding the evolutionary history and domestication process increase the possibility for better exploiting the genetic diversity for cultivar development. The domestication selection in cucurbits was for shape, less bitter flesh, larger and fewer seeds, and larger fruit size, resulting in high genetic diversity within and among cultivated species. This variation can be associated with the wide range of uses that require different shape, size and a constant ratio between fruit length and fruit diameter. The discussion of the breeding history indicates how artificial selection could speed up changes in fruit characteristics to attend specific uses and increase adaptation to a variety of environmental conditions in which cucurbits are growing worldwide. Although interspecific hybridization has been employed in cucurbit breeding more than in any other family, there is still a high potential for increasing its application for germplasm and cultivar development.As cucurbitáceas (Cucurbitaceae são uma das mais importantes famílias de plantas utilizadas para produção de alimentos e fibras. Apesar de a parte aérea das plantas desta família ser muito similar em seu desenvolvimento, grande variabilidade genética tem sido mantida para formato e outras características de fruto, o que aumenta o seu potencial de uso. O objetivo desta revisão foi discutir a origem e a evolução das cucurbitáceas cultivadas. A história da evolução e o conhecimento das alterações ocorridas durante este processo podem facilitar a utiliza

  16. Synthesis of mesoscale, crumpled, reduced graphene oxide roses by water-in-oil emulsion approach

    Science.gov (United States)

    Sharma, Shruti; Pham, Viet H.; Boscoboinik, Jorge A.; Camino, Fernando; Dickerson, James H.; Tannenbaum, Rina

    2018-05-01

    Mesoscale crumpled graphene oxide roses (GO roses) were synthesized by using colloidal graphene oxide (GO) variants as precursors for a hybrid emulsification-rapid evaporation approach. This process produced rose-like, spherical, reduced mesostructures of colloidal GO sheets, with corrugated surfaces and particle sizes tunable in the range of ∼800 nm to 15 μm. Excellent reproducibility for particle size distribution is shown for each selected speed of homogenizer rotor among different sample batches. The morphology and chemical structure of these produced GO roses was investigated using electron microscopy and spectroscopy techniques. The proposed synthesis route provides control over particle size, morphology and chemical properties of the synthesized GO roses.

  17. The origin and composition of cucurbit "phloem" exudate.

    Science.gov (United States)

    Zhang, Cankui; Yu, Xiyan; Ayre, Brian G; Turgeon, Robert

    2012-04-01

    Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem.

  18. The effect of intrinsic crumpling on the mechanics of free-standing graphene

    Science.gov (United States)

    Nicholl, Ryan J. T.; Conley, Hiram J.; Lavrik, Nickolay V.; Vlassiouk, Ivan; Puzyrev, Yevgeniy S.; Sreenivas, Vijayashree Parsi; Pantelides, Sokrates T.; Bolotin, Kirill I.

    2015-11-01

    Free-standing graphene is inherently crumpled in the out-of-plane direction due to dynamic flexural phonons and static wrinkling. We explore the consequences of this crumpling on the effective mechanical constants of graphene. We develop a sensitive experimental approach to probe stretching of graphene membranes under low applied stress at cryogenic to room temperatures. We find that the in-plane stiffness of graphene is 20-100 N m-1 at room temperature, much smaller than 340 N m-1 (the value expected for flat graphene). Moreover, while the in-plane stiffness only increases moderately when the devices are cooled down to 10 K, it approaches 300 N m-1 when the aspect ratio of graphene membranes is increased. These results indicate that softening of graphene at temperatures <400 K is caused by static wrinkling, with only a small contribution due to flexural phonons. Together, these results explain the large variation in reported mechanical constants of graphene devices and pave the way towards controlling their mechanical properties.

  19. Autonomous micromotor based on catalytically pneumatic behavior of balloon-like MnO(x)-graphene crumples.

    Science.gov (United States)

    Chen, Xueli; Wu, Guan; Lan, Tian; Chen, Wei

    2014-07-11

    A novel autonomous micromotor, based on catalytically pneumatic behaviour of balloon-like MnOx-graphene crumples, has been synthesized via an ultrasonic spray pyrolysis method. Through catalytic decomposition of H2O2 into O2, the gas accumulated in a confined space and was released to generate a strong force to push the micromotor.

  20. The Ethno-Botany and utility evaluation of some Species of cucurbits ...

    African Journals Online (AJOL)

    There is the need to develop accurate data, and to put in place more effort toward the cultivation, improvement and conservation of various cucurbits germplasm. An inventory was canned out to track down and document the ethnobotanical uses of the various species of cucurbits found in the Niger Delta areas of Nigeria.

  1. Agrobiodiversity Indices for Three Cucurbit Species in Khorasan- Razavi Province

    Directory of Open Access Journals (Sweden)

    Mehdi Nassiri Mahallati

    2017-09-01

    Full Text Available Introduction The deterioration of genetic resources of many field crops due to monoculture and other agricultural activities has been well documented. Estimates indicate that the introduction of new varieties has contributed at least 80% of the increase in crop production, yet, these gains have been offset by the loss of 90% of landraces. The importance of biodiversity in enhancing the sustainability of crop production in agroecosystems has been well acknowledged in the literature. This has been achieved by increasing the biodiversity at cropping systems, species, and variety levels, which corresponds to biodiversity at the ecosystem, species, and ecotype levels in natural ecosystems. Conservation of biodiversity is prerequisite for sustainable agroecosystems. In the past, diverse species, genotypes and varieties were used in agroecosystems that ensured their sustainability. At present, this approach has changed and new varieties have replaced old ones and on sustainability of systems has been negatively impacted. In the other word, agrobiodiversity or the variety of species in cropping systems has dropped rapidly. Materials and methods In this research, agrobiodiversity of melon (Cucumis.melo var. Inodorus, watermelon (Citrullus Vulgaris and cantaloupe (Cucumis.melo var. Cantaloupensis were evaluated at the genotype and variety levels. For this purpose necessary data including the number of cultivated genotypes or land races and cultivated area for each of them were collected from 25 counties of Khorasan Razavi province. Accurate data was gathered from the appropriate database and also by filling questionnaire for growing season of 2010-2011. Then spatial biodiversity indices of Simpson and Shannon, evenness, and similarity indices of Sorenson were calculated for three cucurbit crops. Results and discussion The results showed that from total cultivated area of cucurbit species in 2010-2011 growing season, 48, 30, 20 and 2 percent belonged to

  2. Cucurbit[6]uril p-xylylenediammonium diiodide decahydrate inclusion complex

    Directory of Open Access Journals (Sweden)

    Wei-Hao Huang

    2008-07-01

    Full Text Available The title inclusion complex, C36H36N24O12·C8H14N22+·2I−·10H2O, displays a large ellipsoidal deformation of the cucurbit[6]uril (CB[6] skeleton upon complex formation. The benzene ring of the cation is rotationally disordered between two orientations in a ratio of 3:1. The solvent H2O molecules form a hydrogen-bonded network by interaction with the carbonyl groups of CB[6] and the I− counterions. The crystal studied exhibited non-merohedral twinning. Both CB[6] and the cation are centrosymmetric.

  3. Acidovorax citrulli: generating basic and applied knowledge to tackle a global threat to the cucurbit industry.

    Science.gov (United States)

    Burdman, Saul; Walcott, Ron

    2012-10-01

    , irregular, water-soaked lesions which later extend through the rind, turn brown and crack. On melon fruits, symptoms are characterized by small, often sunken rind lesions and internal fruit decay. Symptoms on the leaves of mature plants are difficult to diagnose because they are often inconspicuous or similar to those caused by other biotic or abiotic stresses. When they occur, leaf lesions can spread along the midrib and main veins. Lesions appear dark-brown to black on watermelon and light to reddish-brown on melon. Bacterial fruit blotch of cucurbits at APSnet, http://www.apsnet.org/edcenter/intropp/lessons/prokaryotes/Pages/BacterialBlotch.aspx; bacterial fruit blotch guide from ASTA, http://www.amseed.com/pdfs/DiseaseGuide-BFB-English.pdf; Acidovorax citrulli AAC00-1 genome at JGI, http://genome.jgi-psf.org/aciav/aciav.info.html. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  4. Biology of Anastrepha grandis (Diptera: Tephritidae) in Different Cucurbits.

    Science.gov (United States)

    Bolzan, Anderson; Nava, Dori E; Garcia, Flávio R M; Valgas, Ricardo A; Smaniotto, Giovani

    2015-06-01

    Anastrepha grandis (Macquart) (Diptera: Tephritidae) is one of the main pests of cucurbits in Brazil. Losses occur due to the damage caused to the fruits and the embargo on exports, as A. grandis is considered a quarantine pest in countries that import Brazilian cucurbits. This study aimed to evaluate the development of A. grandis in hosts of the Cucurbitaceae family. The hosts used were stem squash (Cucurbita pepo L.), squash (Cucurbita moschata Duchesne), chayote [Sechium edule (Jacq.) Swartz], mini watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai], Spanish melon (Cucumis melo L.), hybrid squash "Tetsukabuto" (C. moschata×Cucurbita maxima Duchesne), and salad cucumber (Cucumis sativus L.). We evaluated the viability and duration of egg-to-pupa period, pupal weight, sex ratio, and average number of pupae per fruit under controlled conditions of temperature, relative humidity, and photophase. The preoviposition and oviposition periods, fecundity, fertility, and longevity of females were determined for adults. Hosts of the genus Cucurbita provided a better development of A. grandis in comparison with other hosts, and presented a greater number of insects on fruit as well as higher infestation rate. Fecundity and longevity were also higher for females that developed in hosts of the genus Cucurbita, although values of these biological parameters varied between stem squash, squash, hybrid squash "Tetsukabuto." © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. A general approach to one-pot fabrication of crumpled graphene-based nanohybrids for energy applications.

    Science.gov (United States)

    Mao, Shun; Wen, Zhenhai; Kim, Haejune; Lu, Ganhua; Hurley, Patrick; Chen, Junhong

    2012-08-28

    Crumpled graphene oxide (GO)/graphene is a new type of carbon nanostructure that has drawn growing attention due to its three-dimensional open structure and excellent stability in an aqueous solution. Here we report a general and one-step approach to produce crumpled graphene (CG)-nanocrystal hybrids, which are produced by direct aerosolization of a GO suspension mixed with precursor ions. Nanocrystals spontaneously grow from precursor ions and assemble on both external and internal surfaces of CG balls during the solvent evaporation and GO crumpling process. More importantly, CG-nanocrystal hybrids can be directly deposited onto various current-collecting substrates, enabling their tremendous potential for energy applications. As a proof of concept, we demonstrate the use of hybrid electrodes of CG-Mn(3)O(4) and CG-SnO(2) in an electrochemical supercapacitor and a lithium-ion battery, respectively. The performance of the resulting capacitor/battery is attractive and outperforms conventional flat graphene-based hybrid devices. This study provides a new and facile route to fabricating high-performance hybrid CG-nanocrystal electrodes for various energy systems.

  6. Differential Life History Trait Associations of Aphids with Nonpersistent Viruses in Cucurbits.

    Science.gov (United States)

    Angelella, G M; Egel, D S; Holland, J D; Nemacheck, J A; Williams, C E; Kaplan, I

    2015-06-01

    The diversity of vectors and fleeting nature of virus acquisition and transmission renders nonpersistent viruses a challenge to manage. We assessed the importance of noncolonizing versus colonizing vectors with a 2-yr survey of aphids and nonpersistent viruses on commercial pumpkin farms. We quantified aphid alightment using pan traps, while testing leaf samples with multiplex RT-PCR targeting cucumber mosaic virus (CMV), zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus (WMV), and papaya ringspot virus (PRSV). Overall, we identified 53 aphid species (3,899 individuals), from which the melon aphid, Aphis gossypii Glover, a pumpkin-colonizing species, predominated (76 and 37% of samples in 2010 and 2011, respectively). CMV and ZYMV were not detected, but WMV and PRSV were prevalent, both regionally (WMV: 28/29 fields, PRSV: 21/29 fields) and within fields (infection rates = 69 and 55% for WMV in 2010 and 2011; 28 and 25% for PRSV in 2010 and 2011). However, early-season samples showed extremely low infection levels, suggesting cucurbit viruses are not seed-transmitted and implicating aphid activity as a causal factor driving virus spread. Interestingly, neither noncolonizer and colonizer alightment nor total aphid alightment were good predictors of virus presence, but community analyses revealed species-specific relationships. For example, cowpea aphid (Aphis craccivora Koch) and spotted alfalfa aphid (Therioaphis trifolii Monell f. maculata) were associated with PRSV infection, whereas the oleander aphid (Aphis nerii Bover de Fonscolombe) was associated with WMV spread within fields. These outcomes highlight the need for tailored management plans targeting key vectors of nonpersistent viruses in agricultural systems. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Crumpled Nitrogen-Doped Graphene for Supercapacitors with High Gravimetric and Volumetric Performances.

    Science.gov (United States)

    Wang, Jie; Ding, Bing; Xu, Yunling; Shen, Laifa; Dou, Hui; Zhang, Xiaogang

    2015-10-14

    Graphene is considered a promising electrochemical capacitors electrode material due to its high surface area and high electrical conductivity. However, restacking interactions between graphene nanosheets significantly decrease the ion-accessible surface area and impede electronic and ionic transfer. This would, in turn, severely hinder the realization of high energy density. Herein, we report a strategy for preparation of few-layer graphene material with abundant crumples and high-level nitrogen doping. The two-dimensional graphene nanosheets (CNG) feature high ion-available surface area, excellent electronic and ion transfer properties, and high packing density, permitting the CNG electrode to exhibit excellent electrochemical performance. In ionic liquid electrolyte, the CNG electrode exhibits gravimetric and volumetric capacitances of 128 F g(-1) and 98 F cm(-3), respectively, achieving gravimetric and volumetric energy densities of 56 Wh kg(-1) and 43 Wh L(-1). The preparation strategy described here provides a new approach for developing a graphene-based supercapacitor with high gravimetric and volumetric energy densities.

  8. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials.

    Science.gov (United States)

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2014-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m 2 g -1 , has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m 2 g -1 /N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m 2 g -1 ) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m 2 g -1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent.

  9. Differential Cotton leaf crumple virus-VIGS-mediated gene silencing and viral genome localization in different Gossypium hirsutum genetic backgrounds

    KAUST Repository

    Idris, Ali; Tuttle, John Richard; Robertson, Dominique Niki; Haigler, Candace H.; Brown, Judith K.

    2010-01-01

    inoculation resulted in systemic and persistent photo-bleaching of the leaves and bolls of the seven cultivars tested, however, the intensity of silencing was variable. CLCrV-VIGS-mediated expression of green fluorescent protein was used to monitor

  10. Complexation (cucurbit[6]uril-pyrene): Thermodynamic and spectroscopic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sueldo Occello, Valeria N.; Rossi, Rita H. de; Veglia, Alicia V., E-mail: aveglia@fcq.unc.edu.ar

    2015-02-15

    The influence of the macrocyclic compound cucurbit[6]uril (CB6) on the photophysical properties of the fluorophore pyrene (PYR) has been studied. Guest–host interaction was observed by UV–visible spectroscopy and spectrofluorimetry. The fluorescence of PYR was significantly increased in the presence of CB6. The binding equilibrium constants for the complex with 1:1 stoichiometry were determined in HCOOH 55% w/v. The values of the association constants, K{sub A}, and the fluorescence quantum yield ratios between complexed and free substrate, ϕ{sup PYR–CB6}/ϕ{sup PYR}, at different temperatures were (3.1±0.9)×10{sup 2} M{sup −1} and (5.1±0.2), (3.6±0.5)×10{sup 2} M{sup −1} and (5.9±0.1), (4.8±0.7)×10{sup 2} M{sup −1} and (5.5±0.1) at 15.0 °C, 25.0 °C and 40.0 °C, respectively. The enthalpic and entropic contributions to the complexation process were determined, yielding ΔS=(92±3) J mol{sup −1} K{sup −1} and ΔH=(13±1) kJ mol{sup −1}. From these results it can be concluded that the complex formation is mainly driven by the entropic term. The forces involved in the complexation are interpreted from the sign and magnitude of the thermodynamic parameters obtained. The partial inclusion of PYR or the formation of a suspended complex is proposed in base of all the data. The interaction is also demonstrated in the solid state by differential scanning calorimetric (DSC) measurements. - Highlights: • The cucurbit[6]uril (CB6) effects on the absorption and fluorescence of pyrene (PYR) were analyzed. • The association constant (K{sub A}) and the stoichiometry of the complex were determined. • The complex formation was confirmed by differential scanning calorimetry (DSC). • The thermodynamic parameters were determined. • The hydrophobic entropic contribution is the main driving force for the PYR–CB6 complex formation.

  11. Epidemiology of Cucurbit yellow stunting disorder virus in the US Southwest and development of virus resistant melon

    Science.gov (United States)

    Cucurbit yellow stunting disorder virus (CYSDV), emerged in the Southwest USA in 2006, where it is transmitted by the MEAM1 cryptic species of Bemisia tabaci. The virus results in late-season infection of spring melon crops with limited economic impact; however, all summer and fall cucurbits become ...

  12. Initiative for international cooperation of researchers and breeders related to determination and denomination of cucurbit powdery mildew races

    Science.gov (United States)

    Cucurbit powdery mildew (CPM) is caused most frequently by two obligate erysiphaceous ectoparasites, Golovinomyces orontii s.l. and Podosphaera xanthii, that are highly variable in virulence. Various independent systems of CPM race determination and denomination cause a chaotic situation in cucurbit...

  13. Phylogenetic analysis of Melon chlorotic leaf curl virus from Guatemala: Another emergent species in the Squash leaf curl virus clade

    KAUST Repository

    Brown, J.K.

    2011-06-01

    The genome of a new bipartite begomovirus Melon chlorotic leaf curl virus from Guatemala (MCLCuV-GT) was cloned and the genome sequence was determined. The virus causes distinct symptoms on melons that were not previously observed in melon crops in Guatemala or elsewhere. Phylogenetic analysis of MCLCuV-GT and begomoviruses infecting cucurbits and other host plant species indicated that its closest relative was MCLCuV from Costa Rica (MCLCuV-CR). The DNA-A components of two isolates shared 88.8% nucleotide identity, making them strains of the same species. Further, both MCLCuV-GT and MCLCuV-CR grouped with other Western Hemisphere cucurbit-infecting species in the SLCV-clade making them the most southerly cucurbit-infecting members of the clade to date. Although the common region of the cognate components of MCLCuV-GT and MCLCuV-CR, shared similar to 96.3% nucleotide identity. While DNA-A and DNA-B components of MCLCuV-GT were less than 86% nucleotide identity with the respective DNAA and DNA-B common regions of MCLCuV-CR. The late viral genes of the two strains shared the least nt identity (<88%) while their early genes shared the highest nt identity (>90%). The collective evidence suggests that these two strains of MCLCuV are evolutionarily divergent owing in part to recombination, but also due to the accumulation of a substantial number of mutations. In addition they are differentially host-adapted, as has been documented for other cucurbit-infecting, bean-adapted, species in the SLCV clade. (C) 2011 Elsevier B.V. All rights reserved.

  14. Interaction of Cucurbit(5)uril with U(VI) in formic acid water medium

    International Nuclear Information System (INIS)

    Rawat, Neetika; Kar, Aishwarya; Tomar, B.S.; Nayak, S.K.; Mohapatra, M.

    2015-01-01

    Cucurbit(n)urils (CBn) are a new class of macrocyclic cage compounds capable of binding organic and inorganic species, owing to their unique pumpkin like structure comprising of both hydrophobic cavity and hydrophilic portal. Complexation of U(VI) with Cucurbit(5)uril (CB5) in 50 wt% formic acid medium has been studied by UV-Vis spectroscopy. In order to understand the species formed, the interaction of formic acid with CB5 was studied by monitoring fluorescence of CB5. Formic was found to form 1:1 species with interaction constant (K) 17.4 M -1 . (author)

  15. First report of zucchini tigre mosaic virus infecting several cucurbit plants in China

    Science.gov (United States)

    Pumpkin (Cucurbita moschata Duch.), Cucumber (Cucumis sativus Linn.) and Zucchini (Cucurbita pepo Linn.) are important crops in tropical and subtropical regions in the world, and they are popular vegetable crops in China. There are currently 59 viruses known infecting cucurbit plants which including...

  16. Hydrophilic Cucurbit[7]uril-Pseudorotaxane-Anchored-Monolayer-Protected Gold Nanorods

    Science.gov (United States)

    2013-03-20

    FULL PAPER DOI:10.1002/ejic.201300010 Hydrophilic Cucurbit[7]uril-Pseudorotaxane-Anchored- Monolayer-Protected Gold Nanorods Xiang Ma,[a] Yuhua Xue... Cao , Q. Wang, H. Tian, Chem. Commun. 2011, 47, 3559–3561. [8] a) I. Hwang, K. Baek, M. Jung, Y. Kim, K. M. Park, D. W. Lee, N. Selvapalam, K. Kim, J. Am

  17. Application of a new approach for study of virulence variation in cucurbit powdery mildew populations

    Science.gov (United States)

    Cucurbit powdery mildew (CPM) is caused by two obligate ectoparasites, Golovinomyces orontii s.l. (Go) and Podosphaera xanthii (Px), that are highly variable in virulence. Various systems of CPM race determination and denomination were used (Lebeda et al. 2011). We developed new tools to enhance res...

  18. Cucurbit[8]uril templated supramolecular ring structure formation and protein assembly modulation

    NARCIS (Netherlands)

    Ramaekers, M.; Wijnands, S.P.W.; van Dongen, J.L.J.; Brunsveld, L.; Dankers, P.Y.W.

    2015-01-01

    The interplay of Phe-Gly-Gly (FGG)-tagged proteins and bivalent FGG-tagged penta(ethylene glycol) as guest molecules with cucurbit[8]uril (Q8) hosts is studied to modulate the supramolecular assembly process. Ring structure formation of the bivalent guest molecule with Q8 leads to enhanced binding

  19. Complexation of Cucurbit(7)uril with Eu(III)

    International Nuclear Information System (INIS)

    Kar, Aishwarya; Rawat, Neetika; Rao, Ankita; Tomar, B.S.; Nayak, S.K.; Ray, Alok

    2014-01-01

    Cucurbiturils (CBs) CB(n)s are macrocyclic molecules with carbonyl groups at the portals, which bind cations through ion dipole interactions and the cavity which stabilize hydrophobic moieties. The size of the portal and the volume of the interior cavities of CB(n)s are dependent on the number of glycoluril units present in CBs. CBs are widely used as supramolecular host systems in applications, such as formation of supramolecular hydrogels, drug delivery systems. Though the binding of CBs with organic guest molecules have been studied extensively where as metal complexation studies are very few. In the present work, complexation studies of Cucurbit(7)uril (with seven glycouril units, CB7) with Eu(III) were carried out using fluorescence, UV-vis spectrophotometry. The stability constant for 1:1 complex CB7-Eu(III) complex determined by monitoring the change in CB7 UV- vis absorption spectra on addition of Eu(III) was found to be 2.99 ± 0.08. The fluorescence spectra of increasing ligand to metal ratio exhibited the increase in the intensity ratio of peak at 616 and 592 which is the measure of complexation of Eu(III) with CB7 and was used to deduce the stability constant and the value (2.82 ± 0.07) obtained was in good agreement with that obtained from UV vis spectroscopy. Further, the life time of Eu(III) ion, which increased with CB7 to Eu(III) ratio, was used to deduce number of water molecules around Eu(III) metal ion which were found to decrease from 9 to 3 thereby suggesting inner sphere complexation. The stability constant of CB7 with Eu(III) is one order of magnitude less than CB5, derived in separate study by authors. The smaller cavity of CB5 (2.4 A 0 ) favors its interactions with Eu(III) ion of comparable diameter (2.16 A 0 ) leading to higher stability constant compared to CB7 (5.4 A 0 ) having larger cavity

  20. Cucurbit[6]uril: A Possible Host for Noble Gas Atoms.

    Science.gov (United States)

    Pan, Sudip; Mandal, Subhajit; Chattaraj, Pratim K

    2015-08-27

    Density functional and ab initio molecular dynamics studies are carried out to investigate the stability of noble gas encapsulated cucurbit[6]uril (CB[6]) systems. Interaction energy, dissociation energy and dissociation enthalpy are calculated to understand the efficacy of CB[6] in encapsulating noble gas atoms. CB[6] could encapsulate up to three Ne atoms having dissociation energy (zero-point energy corrected) in the range of 3.4-4.1 kcal/mol, whereas due to larger size, only one Ar or Kr atom encapsulated analogues would be viable. The dissociation energy value for the second Ar atom is only 1.0 kcal/mol. On the other hand, the same for the second Kr is -0.5 kcal/mol, implying the instability of the system. The noble gas dissociation processes are endothermic in nature, which increases gradually along Ne to Kr. Kr encapsulated analogue is found to be viable at room temperature. However, low temperature is needed for Ne and Ar encapsulated analogues. The temperature-pressure phase diagram highlights the region in which association and dissociation processes of Kr@CB[6] would be favorable. At ambient temperature and pressure, CB[6] may be used as an effective noble gas carrier. Wiberg bond indices, noncovalent interaction indices, electron density, and energy decomposition analyses are used to explore the nature of interaction between noble gas atoms and CB[6]. Dispersion interaction is found to be the most important term in the attraction energy. Ne and Ar atoms in one Ng entrapped analogue are found to stay inside the cavity of CB[6] throughout the simulation at 298 K. However, during simulation Ng2 units in Ng2@CB[6] flip toward the open faces of CB[6]. After 1 ps, one Ne atom of Ne3@CB[6] almost reaches the open face keeping other two Ne atoms inside. At lower temperature (77 K), all the Ng atoms in Ngn@CB[6] remain well inside the cavity of CB[6] throughout the simulation time (1 ps).

  1. The Effect of Different Cucurbit Rootstocks on Some Morphological and Physiological Traits of Cucumber (Cucumis sativus cv. Super Dominus

    Directory of Open Access Journals (Sweden)

    reihane Mesgari

    2017-02-01

    Full Text Available Introduction: Cucumber is one of the most important vegetable crops for the local consumption and exportation. The use of grafted vegetable seedlings has been popular in many countries during recent years. Growing fruit-bearing vegetables, chiefly tomato, cucumber and watermelon through grafted seedlings become a widespread practice worldwide. Grafting is a valuable technique to avoid soil-borne diseases, provide biotic and abiotic stress tolerance, enhance nutrient uptake, optimize water use, and increase fruit yield and quality. Vegetable grafting is a new topic in Iran and there are a limited number of studies on grafted vegetable production. However, attention to grafting by researchers has recently increased. Suitable rootstocks should be identified and characterized for the effective utilization of grafting. The rootstock's vigorous root system increases the efficiency of water and nutrient absorption, and may also serve as a source of endogenous plant hormones, thus leading to increased growth and yield in addition to disease control. In the present study, we investigated the response of two Cucurbita sp. and an Iranian melon as rootstocks for cucumber. Materials and methods: In order to study the effect of cucurbit rootstocks and grafting method on growth, yield and fruit quality of cucumber (Cucumis sativus cv. Super Dominus, an experiment was conducted as a factorial design in the base of RCBD with three replications in the greenhouse and research farm, University of Zanjan. Treatments were included three rootstocks (Cucurbita moschata L., Lagenaria siceraria and Cucumis melo L. and ungrafted plants (control and two grafting method (hole insertion and splice grafting. Seeds were sown simultaneously in plastic pots. For obtaining the same stem diameter of scion and rootstocks, cucumber seeds were planted four days earlier than rootstocks seeds. The seedlings were grown in an environment-controlled greenhouse with 25/20 day

  2. Cucurbit[7]uril as a tool in the green synthesis of gold nanoparticles.

    Science.gov (United States)

    Premkumar, Thathan; Geckeler, Kurt E

    2010-12-03

    A simple, green, one-pot synthesis of gold nanoparticles was achieved through the reaction of an aqueous mixture of potassium tetrachloroaurate(III) and the macrocycle cucurbit[7]uril in the presence of sodium hydroxide at room temperature without introducing any kind of traditional reducing agents and/or external energy. The as-prepared gold nanoparticles showed catalytic activity for the reduction reaction of 4-nitrophenol in the presence of NaBH(4), which has been established by visual inspection and UV/Vis spectroscopy. This report is the first for the preparation of gold nanoparticles using cucurbit[7]uril in aqueous media through chemical reduction without employing conventional reducing agents and/or external energy.

  3. Co-grinding Effect on Crystalline Zaltoprofen with ?-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    OpenAIRE

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-01-01

    This work aimed to investigate the co-grinding effects of ?-cyclodextrin (?-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline Z...

  4. Cucurbits depicted in Byzantine mosaics from Israel, 350–600 ce

    Science.gov (United States)

    Avital, Anat; Paris, Harry S.

    2014-01-01

    Background and Aims Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region. Results and Conclusions Twenty-three mosaics dating from 350–600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round–pyriform and probably used as vessels. PMID:24948671

  5. CHARACTERIZATION OF CUCURBIT PRODUCTION SYSTEMS AND DISEASE PREVALENCE IN MUNICIPALITIES IN PERNAMBUCO

    Directory of Open Access Journals (Sweden)

    GERFFESON THIAGO MOTA DE ALMEIDA SILVA

    2016-01-01

    Full Text Available Cucurbits have great economic, nutritional and social importance in the Brazilian semiarid region. In this region, many factors can result in reduced productivity of these crops, especially fungal and viral diseases. Therefore, knowledge of cucurbits is crucial for proper disease management. The objective of this work was to identify the major diseases of cucurbits grown in some municipalities in the Hinterland of the state of Pernambuco. Thus, plant samples were collected with symptoms in crops in the municipalities of Salgueiro, Serra Talhada, Floresta, Petrolândia, Ibimirim, Custódia and Inajá. A questionnaire was also applied to gather information about the production profile of producers. Seven fungal pathogens infecting cucurbits were identified: Pseudoperonospora cubensis, Colletotrichum sp., Podosphaera xanthii, Rhizoctonia solani, Didymella bryoniae, Fusarium sp. e Alternaria sp., and three viruses as well: Papaya ringspot virus - watermelon strain (PRSV-W, Watermelon mosaic virus (WMV, Zucchini yellow mosaic virus (ZYMV. It was found that in small crops, there is limited search for technical information om cropping, and these crops originate mostly from native seeds, in contrast to medium and large producers, who use improved cultivars. The melon and watermelon crops are the most commercially exploited, while pumpkins are used in subsistence agriculture. As for plant health problems, most respondents reported knowing the main diseases that occur in crops and perform disease control based on personal experience and / or through the help of the technical assistance provided by agricultural stores. In a few cases, in large farms, there was an agronomist to assist in this type of control.

  6. Cucurbits depicted in Byzantine mosaics from Israel, 350-600 ce.

    Science.gov (United States)

    Avital, Anat; Paris, Harry S

    2014-08-01

    Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region. Twenty-three mosaics dating from 350-600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round-pyriform and probably used as vessels. © The Author 2014. Published by Oxford University Press on behalf of

  7. The Origin and Composition of Cucurbit “Phloem” Exudate1[OA

    Science.gov (United States)

    Zhang, Cankui; Yu, Xiyan; Ayre, Brian G.; Turgeon, Robert

    2012-01-01

    Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem. PMID:22331409

  8. Incidence and molecular diversity of poleroviruses infecting cucurbit crops and weed plants in Thailand.

    Science.gov (United States)

    Cheewachaiwit, S; Warin, N; Phuangrat, B; Rukpratanporn, S; Gajanandana, O; Balatero, C H; Chatchawankanphanich, O

    2017-07-01

    Overall, 244 samples of cucurbit crops with yellowing symptoms and selected weed species, from 15 provinces in Thailand, were screened by RT-PCR using primers Polero-CP-F and Polero-CP-R. A total of 160 samples (~66%) were infected by poleroviruses. Analysis of a 1.4 kb region covering the 3' RNA-dependent RNA polymerase (RdRp) gene, the intergenic non-coding region (iNCR), and the coat protein (CP), showed that four poleroviruses, namely, cucurbit aphid-borne yellows virus (CABYV), luffa aphid-borne yellows virus (LABYV), melon aphid-borne yellows virus (MABYV) and suakwa aphid-borne yellows virus (SABYV) were associated with the yellowing symptoms in cucurbit crops. Further analyses indicated presence of putative recombinant viruses referred to as CABYV-R and SABYV-R. CABYV-R was derived from the recombination between MABYV and the common strain of CABYV (CABYV-C). SABYV-R was derived from the recombination of MABYV and SABYV.

  9. 3 D Network-Structured Crumpled Graphene/Carbon Nanotube/Polyaniline Composites for Supercapacitors.

    Science.gov (United States)

    Jo, Eun H; Jang, Hee D; Chang, Hankwon; Kim, Sun K; Choi, Ji-Hyuk; Lee, Chong M

    2017-05-22

    Crumpled graphene (CGR) is considered a promising supercapacitor material to achieve high power and energy density because it could overcome the disadvantages of 2 D GR sheets such as aggregation during the electrode fabrication process, reduction of the available surface area, and limitation of the electron and ion transport. Even though CGR shows good results, carbon materials are limited in terms of their capacitance performance. Here, we report highly enhanced supercapacitor materials by fabricating a 3 D composite containing CGR, carbon nanotubes (CNTs), and polyaniline (PANI). The CNTs increased the basal spacing and bridged the defects for electron transfer between the GR sheets in CGR. PANI can enhance the rate of conduction of electrons and offer high pseudocapacitance originating from its redox reactions. The synergistic effect of the CNTs and PANI may also result in a higher electrochemical capacitance and better stability than each individual component as electrode materials for supercapacitors in a two-electrode system. More importantly, the performance of the supercapacitors can be further enhanced by employing 2 D GR as the binder for the composite electrodes, resulting in specific capacitance of 456 F g -1 , rate capability of 89 %, and cyclic stability of 97 % after 1000 cycles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

    Science.gov (United States)

    Kim, In Gyeom; Nah, In Wook; Oh, In-Hwan; Park, Sehkyu

    2017-10-01

    Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.

  11. Molecular diversity of poleroviruses infecting cucurbit crops in four countries reveals the presence of members of six distinct species.

    Science.gov (United States)

    Knierim, D; Tsai, W S; Maiss, E; Kenyon, L

    2014-06-01

    When 66 cucurbit samples with yellowing symptoms from fields in Mali, the Philippines, Thailand and Uzbekistan were screened by RT-PCR using universal polerovirus primers, 21 were identified as harboring polerovirus RNA. When these 21 samples were screened with specific primers for the known cucurbit-infecting poleroviruses, suakwa aphid-borne yellows virus and a recombinant strain of cucurbit aphid-borne yellows virus were detected for the first time in the Philippines and Thailand. However, seven polerovirus-positive samples did not react with any of the known species-specific primers. Sequencing of 1.4-kb universal polerovirus RT-PCR products revealed the presence of two poleroviruses that had not been described previously. These viruses, from Mali and Thailand, were provisionally named pepo aphid-borne yellows virus and luffa aphid-borne yellows virus, respectively.

  12. Comparative proteomics of cucurbit phloem indicates both unique and shared sets of proteins.

    Science.gov (United States)

    Lopez-Cobollo, Rosa M; Filippis, Ioannis; Bennett, Mark H; Turnbull, Colin G N

    2016-11-01

    Cucurbits are well-studied models for phloem biology but unusually possess both fascicular phloem (FP) within vascular bundles and additional extrafascicular phloem (EFP). Although the functional differences between the two systems are not yet clear, sugar analysis and limited protein profiling have established that FP and EFP have divergent compositions. Here we report a detailed comparative proteomics study of FP and EFP in two cucurbits, pumpkin and cucumber. We re-examined the sites of exudation by video microscopy, and confirmed that in both species, the spontaneous exudate following tissue cutting derives almost exclusively from EFP. Comparative gel electrophoresis and mass spectrometry-based proteomics of exudates, sieve element contents and microdissected stem tissues established that EFP and FP profiles are highly dissimilar, and that there are also species differences. Searches against cucurbit databases enabled identification of more than 300 FP proteins from each species. Few of the detected proteins (about 10%) were shared between the sieve element contents of FP and EFP, and enriched Gene Ontology categories also differed. To explore quantitative differences in the proteomes, we developed multiple reaction monitoring methods for cucumber proteins that are representative markers for FP or EFP and assessed exudate composition at different times after tissue cutting. Based on failure to detect FP markers in exudate samples, we conclude that FP is blocked very rapidly and therefore makes a minimal contribution to the exudates. Overall, the highly divergent contents of FP and EFP indicate that they are substantially independent vascular compartments. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  13. Distribution and molecular diversity of three cucurbit-infecting poleroviruses in China.

    Science.gov (United States)

    Shang, Qiao-xia; Xiang, Hai-ying; Han, Cheng-gui; Li, Da-wei; Yu, Jia-lin

    2009-11-01

    Cucurbit aphid-borne yellows virus (CABYV) and Melon aphid-borne yellows virus (MABYV) have been found to be associated with cucurbit yellowing disease in China. Our report identifies for the first time a third distinct polerovirus, tentatively named Suakwa aphid-borne yellows virus (SABYV), infecting Suakwa vegetable sponge. To better understand the distribution and molecular diversity of these three poleroviruses infecting cucurbits, a total of 214 cucurbitaceous crop samples were collected from 25 provinces in China, and were investigated by RT-PCR and sequencing. Of these, 108 samples tested positive for CABYV, while 40 samples from five provinces were positive for MABYV, and SABYV was detected in only 4 samples which were collected in the southern part of China. Forty-one PCR-amplified fragments containing a portion of the RdRp gene, intergenic NCR and CP gene were cloned and sequenced. Sequence comparisons showed that CABYV isolates shared 78.0-79.2% nucleotide sequence identity with MABYV isolates, and 69.7-70.8% with SABYV. Sequence identity between MABYV and SABYV was 73.3-76.5%. In contrast, the nucleotide identities within each species were 93.2-98.7% (CABYV), 98.1-99.9% (MABYV), and 96.1-98.6% (SABYV). Phylogenetic analyses revealed that the polerovirus isolates fit into three distinct groups, corresponding to the three species. The CABYV group could be further divided into two subgroups: the Asia subgroup and the Mediterranean subgroup, based on CP gene and partial RdRp gene sequences. Recombination analysis suggested that MABYV may be a recombinant virus.

  14. Smart supramolecular sensing with cucurbit[n]urils: probing hydrogen bonding with SERS.

    Science.gov (United States)

    de Nijs, Bart; Kamp, Marlous; Szabó, Istvan; Barrow, Steven J; Benz, Felix; Wu, Guanglu; Carnegie, Cloudy; Chikkaraddy, Rohit; Wang, Wenting; Deacon, William M; Rosta, Edina; Baumberg, Jeremy J; Scherman, Oren A

    2017-12-04

    Rigid gap nano-aggregates of Au nanoparticles formed using cucurbit[n]uril (CB[n]) molecules are used to investigate the competitive binding of ethanol and methanol in an aqueous environment. We show it is possible to detect as little as 0.1% methanol in water and a ten times higher affinity to methanol over ethanol, making this a useful technology for quality control in alcohol production. We demonstrate strong interaction effects in the SERS peaks, which we demonstrate are likely from the hydrogen bonding of water complexes in the vicinity of the CB[n]s.

  15. FLOWERING LOCUS T protein may act as the long-distance florigenic signal in the cucurbits.

    Science.gov (United States)

    Lin, Ming-Kuem; Belanger, Helene; Lee, Young-Jin; Varkonyi-Gasic, Erika; Taoka, Ken-Ichiro; Miura, Eriko; Xoconostle-Cázares, Beatriz; Gendler, Karla; Jorgensen, Richard A; Phinney, Brett; Lough, Tony J; Lucas, William J

    2007-05-01

    Cucurbita moschata, a cucurbit species responsive to inductive short-day (SD) photoperiods, and Zucchini yellow mosaic virus (ZYMV) were used to test whether long-distance movement of FLOWERING LOCUS T (FT) mRNA or FT is required for floral induction. Ectopic expression of FT by ZYMV was highly effective in mediating floral induction of long-day (LD)-treated plants. Moreover, the infection zone of ZYMV was far removed from floral meristems, suggesting that FT transcripts do not function as the florigenic signal in this system. Heterografting demonstrated efficient transmission of a florigenic signal from flowering Cucurbita maxima stocks to LD-grown C. moschata scions. Real-time RT-PCR performed on phloem sap collected from C. maxima stocks detected no FT transcripts, whereas mass spectrometry of phloem sap proteins revealed the presence of Cm-FTL1 and Cm-FTL2. Importantly, studies on LD- and SD-treated C. moschata plants established that Cmo-FTL1 and Cmo-FTL2 are regulated by photoperiod at the level of movement into the phloem and not by transcription. Finally, mass spectrometry of florally induced heterografted C. moschata scions revealed that C. maxima FT, but not FT mRNA, crossed the graft union in the phloem translocation stream. Collectively, these studies are consistent with FT functioning as a component of the florigenic signaling system in the cucurbits.

  16. POMICS: A Simulation Disease Model for Timing Fungicide Applications in Management of Powdery Mildew of Cucurbits.

    Science.gov (United States)

    Sapak, Z; Salam, M U; Minchinton, E J; MacManus, G P V; Joyce, D C; Galea, V J

    2017-09-01

    A weather-based simulation model, called Powdery Mildew of Cucurbits Simulation (POMICS), was constructed to predict fungicide application scheduling to manage powdery mildew of cucurbits. The model was developed on the principle that conditions favorable for Podosphaera xanthii, a causal pathogen of this crop disease, generate a number of infection cycles in a single growing season. The model consists of two components that (i) simulate the disease progression of P. xanthii in secondary infection cycles under natural conditions and (ii) predict the disease severity with application of fungicides at any recurrent disease cycles. The underlying environmental factors associated with P. xanthii infection were quantified from laboratory and field studies, and also gathered from literature. The performance of the POMICS model when validated with two datasets of uncontrolled natural infection was good (the mean difference between simulated and observed disease severity on a scale of 0 to 5 was 0.02 and 0.05). In simulations, POMICS was able to predict high- and low-risk disease alerts. Furthermore, the predicted disease severity was responsive to the number of fungicide applications. Such responsiveness indicates that the model has the potential to be used as a tool to guide the scheduling of judicious fungicide applications.

  17. MODULATION OF GROWTH AND PROTON PUMPING ATPase ACTIVITY OF PROBIOTIC Lactobacilli BY DIETARY CUCURBITS

    Directory of Open Access Journals (Sweden)

    Irfan Ahmad

    2013-12-01

    Full Text Available Gastrointestinal tract predominantly harbor probiotic Lactobacilli which exert beneficial effects on human health. Aqueous extracts from fruits of Lagenaria siceraria (Ls, Luffa cylindrica (Lc and Cucurbita maxima (Cm were prepared and lyophilized. Fruit extracts were investigated for their effects on Lactobacillus rhamnosus (L. rhamnosus, Lactobacillus plantarum (L. plantarum and Lactobacillus acidophilus (L. acidophilus. Extracts were found to enhance growth of Lactobacilli without any toxic effect (up to 1000µg/mL concentration. Minimum concentration of extracts at which growth of probiotic strains were found to be enhanced significantly were determined (103.67 µg/mL-118µg/mL and considered as effective concentration (EC or growth stimulatory concentration (GSC. Proton pumping ATPase activity of Lactobacilli were examined and found to be enhanced significantly (29.89- 61.96% in extracts treated probiotics (Lactobacilli as compared to the normal control. Inulin used as positive control and found to enhance the proton efflux activity (28.06-37.72% with respect to the control. These dietary cucurbits enhance metabolic activity of probiotic Lactobacilli by modulating their proton pumping ATPase mechanism. This study suggested that the consumption of cucurbit fruits might be a natural source of enhancing the activities of probiotic Lactobacilli in the gut.

  18. Florigenic effects of IAA for improving pistillate and staminate flowering in some cucurbits under Pb stress

    International Nuclear Information System (INIS)

    Khan, A.S.; Chaudhary, N.Y.

    2010-01-01

    This study contributes to the enhancement of on knowledge about behaviour of cucurbits with heavy metal i.e., Pb (NO/sub 3/)/sub 2/ and/or their combination with growth hormones (IAA). Effects of Pb and IAA were studied on flowering in Cucumis sativus L. and Momordica charantia L. There is very little information on the effects of heavy metals on the flowering in plants particularly in cucurbits; this in itself makes the issue of interest apart from the interaction of heavy metals with hormones. Plant under the stress of heavy metals can be treated with growth hormones to improve growth parameters, to avoid delay in flowering and likewise quality of fruit can be improved. Applied 400 mg/l IAA caused precocious flowering, increasing the number of flowers in both the plants. Lead caused significant delay in flowering, consequently leading to reduction in the number of pistillate and staminate flowers. However, when IAA was applied with Pb (NO/sub 3/)/sub 2/, there was less decrease in staminate and pistillate flowers, revealing the dominant effect of IAA. Current study reveals that inhibitory effects of heavy metals on flowering were partially restored by IAA applications. (author)

  19. Evaluation of native bees as pollinators of cucurbit crops under floating row covers.

    Science.gov (United States)

    Minter, Logan M; Bessin, Ricardo T

    2014-10-01

    Production of cucurbit crops presents growers with numerous challenges. Several severe pests and diseases can be managed through the use of rotation, trap cropping, mechanical barriers, such as row covers, and chemical applications. However, considerations must also be made for pollinating insects, as adequate pollination affects the quantity and quality of fruit. Insecticides may negatively affect pollinators; a concern enhanced in recent years due to losses in managed Apis melifera L. colonies. Row covers can be used in place of chemical control before pollination, but when removed, pests have access to fields along with the pollinators. If pollination services of native bees could be harnessed for use under continuous row covers, both concerns could be balanced for growers. The potential of two bee species which specialize on cucurbit flowers, Peponapis pruinosa Say and Xenoglossa strenua Cresson, were assessed under continuous row covers, employed over acorn squash. Experimental treatments included plots with either naturally or artificially introduced bees under row covers and control plots with row covers either permanently removed at crop flowering, or employed continuously with no added pollinating insects. Pests in plots with permanently removed row covers were managed using standard practices used in certified organic production. Marketable yields from plots inoculated with bees were indistinguishable from those produced under standard practices, indicating this system would provide adequate yields to growers without time and monetary inputs of insecticide applications. Additionally, application of this technique was investigated for muskmelon production and discussed along with considerations for farm management.

  20. Oviposition punctures in cucurbit fruits and their economic damage caused by the sterile female melon fly, Bactrocera cucurbitae Coquillett

    International Nuclear Information System (INIS)

    Miyatake, T.; Irabu, T.; Higa, R.

    1993-01-01

    Oviposition punctures caused by sterile females of the tephritid Bactrocera cucurbitae in cucurbit fruits were examined and economic damage was evaluated in Okinawa, Ryukyu Archipelago, Japan. Cage experiments in the field confirmed that sterile females make punctures (sterile stings) on fruits. The features of sterile stings differed depending on fruit species and were classified into 5 types

  1. A new approach for weed control in a cucurbit field employing an attenuated potyvirus-vector for herbicide resistance.

    Science.gov (United States)

    Shiboleth, Y M; Arazi, T; Wang, Y; Gal-On, A

    2001-12-14

    Expression of bar, a phosphinothricin acetyltransferase, in plant tissues, leads to resistance of these plants to glufosinate ammonium based herbicides. We have created a bar expressing, attenuated zucchini yellow mosaic potyvirus-vector, AGII-Bar, to enable herbicide use in cucurbit fields. The parental vector, ZYMV-AGII, has been rendered environmentally safe by both disease-symptom attenuation and aphid-assisted virus transmission abolishment. The recombinant AGII-Bar virus-encoding cDNA, when inoculated on diverse cucurbits was highly infectious, accumulated to similar levels as AGII, and elicited attenuated AGII-like symptoms. Potted cucurbits inoculated with AGII-Bar became herbicide resistant about a week post-inoculation. Herbicide resistance was sustained in squash over a period of at least 26 days and for at least 60 days in cucumber grown in a net-house under commercial conditions. To test the applicability of AGII-Bar use in a weed-infested field, a controlled experiment including more than 450 plants inoculated with this construct, was performed. Different dosages of glufosinate ammonium were sprayed, 2 weeks after planting, on the foliage of melons, cucumbers, squash, and watermelons. AGII-Bar provided protection to all inoculated plants, of every variety tested, at each dosage applied, including the highest doses that totally eradicated weeds. This study demonstrates that AGII-Bar can be utilized to facilitate weed control in cucurbits and exemplifies the practical potential of attenuated virus-vector use in agriculture.

  2. An eco-friendly in situ activatable antibiotic via cucurbit[8]uril-mediated supramolecular crosslinking of branched polyethylenimine.

    Science.gov (United States)

    Li, Shengke; Jiang, Nan; Zhao, Wenxuan; Ding, Yuan-Fu; Zheng, Ying; Wang, Lian-Hui; Zheng, Jun; Wang, Ruibing

    2017-05-30

    We report an unprecedented, eco-friendly, in situ activatable model antibiotic, phenylalanyl-polyethylenimine (PhePEI), to potentially diminish antibiotic pollution of the environment and associated antibiotic resistance. The inactive PhePEI can be reversibly activated upon supramolecular crosslinking by cucurbit[8]uril, conferring potent antibacterial activity.

  3. First report of the cucurbit yellow vine disease caused by Serratia marcescens in watermelon and yellow squash in Alabama

    Science.gov (United States)

    Symptoms typical of cucurbit yellow vine disease (CYVD) were first observed in a 2 ha watermelon field in Crawford, Russell County, Alabama on 8 June 2010. Watermelon plants, cv. 'Jubilee,' exhibited a yellow or chlorotic appearance and some plants were completely wilted. On 24 June plant samples ...

  4. Cucurbit powdery mildew-resistant bitter gourd breeding lines reveal four races of Podosphaera xanthii in Asia

    Science.gov (United States)

    Bitter gourd (Momordica charantia L.) is a commercially and nutritionally important market vegetable in Asia cultivated mainly by smallholder farmers. Cucurbit powdery mildew (CPM) caused by Podosphaera xanthii (Px) is a nearly ubiquitous and serious fungal disease of bitter gourd. Five bitter gourd...

  5. A facile approach to prepare crumpled CoTMPyP/electrochemically reduced graphene oxide nanohybrid as an efficient electrocatalyst for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Juanjuan, E-mail: majj0518@hotmail.com [Department of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005 (China); School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore (Singapore); Liu, Lin; Chen, Qian; Yang, Min [Department of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005 (China); Wang, Danping [School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore (Singapore); Tong, Zhiwei [Department of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005 (China); Chen, Zhong, E-mail: aszchen@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore (Singapore)

    2017-03-31

    Highlights: • Crumpled CoTMPyP/ERGO hybrid was successfully prepared by a facile two-step process. • CoTMPyP nanoaggregates are homogeneously distributed over the graphene surface. • CoTMPyP/ERGO hybrid film shows good electrocatalytic activity and stability for HER. - Abstract: Elaborate design and synthesis of efficient and stable non-Pt electrocatalysts for some renewable energy related conversion/storage processes are one of the major goals of sustainable chemistry. Herein, we report a facile method to fabricate Co porphyrin functionalized electrochemically reduced graphene oxide (CoTMPyP/ERGO) thin film by direct assembly of oppositely charged tetrakis(N-methylpyridyl) porphyrinato cobalt (CoTMPyP) and GO nanosheets under mild conditions followed by an electrochemical reduction procedure. STEM analysis confirms that CoTMPyP nanoaggregates are homogeneously distributed over the graphene surface. The electrochemical properties of CoTMPyP/ERGO were investigated by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy. The results demonstrate that CoTMPyP/ERGO nanohybrid film can serve as excellent electrocatalyst for hydrogen evolution in alkaline solution with high activity and stability. The intimate contact and efficient electron transfer between CoTMPyP and ERGO, as well as the crumpled structure, contribute to the improvement of the electrocatalytic performance.

  6. Supramolecular Encapsulation of Vitamin B6 by Macrocyclic Nanocontainer Cucurbit[7]uril

    Directory of Open Access Journals (Sweden)

    Wanying Li

    2015-01-01

    Full Text Available A pharmaceutically and biologically relevant molecule, pyridoxine hydrochloride (vitamin B6, was encapsulated inside the cavity of a molecular container, cucurbit[7]uril (CB[7], in aqueous solution. The CB[7] based “nanocapsule” of vitamin B6 has been investigated for the first time, via 1H NMR and UV-visible spectroscopic titrations (including Job’s plot and ab initio molecular modeling. The results have demonstrated that vitamin B6 forms stable host-guest complexes within CB[7] in 1 : 1 stoichiometry, with a binding affinity of (4.0±0.5×103 M−1. Such a nanocapsule could potentially find application in vitamin B6 formulation for the purpose of enhancing the stability, absorption, and delivery of this important vitamin.

  7. Acid-Labile Acyclic Cucurbit[n]uril Molecular Containers for Controlled Release.

    Science.gov (United States)

    Mao, Dake; Liang, Yajun; Liu, Yamin; Zhou, Xianhao; Ma, Jiaqi; Jiang, Biao; Liu, Jia; Ma, Da

    2017-10-02

    Stimuli-responsive molecular containers are of great importance for controlled drug delivery and other biomedical applications. A new type of acid labile acyclic cucurbit[n]uril (CB[n]) molecular containers is presented that can degrade and release the encapsulated cargo at accelerated rates under mildly acidic conditions (pH 5.5-6.5). These containers retain the excellent recognition properties of CB[n]-type hosts. A cell culture study demonstrated that the cellular uptake of cargos could be fine-tuned by complexation with different containers. The release and cell uptake of cargo dye was promoted by acidic pH. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Complete sequence analysis reveals two distinct poleroviruses infecting cucurbits in China.

    Science.gov (United States)

    Xiang, Hai-ying; Shang, Qiao-xia; Han, Cheng-gui; Li, Da-wei; Yu, Jia-lin

    2008-01-01

    The complete RNA genomes of a Chinese isolate of cucurbit aphid-borne yellows virus (CABYV-CHN) and a new polerovirus tentatively referred to as melon aphid-borne yellows virus (MABYV) were determined. The entire genome of CABYV-CHN shared 89.0% nucleotide sequence identity with the French CABYV isolate. In contrast, nucleotide sequence identities between MABYV and CABYV and other poleroviruses were in the range of 50.7-74.2%, with amino acid sequence identities ranging from 24.8 to 82.9% for individual gene products. We propose that CABYV-CHN is a strain of CABYV and that MABYV is a member of a tentative distinct species within the genus Polerovirus.

  9. Toxicology and drug delivery by cucurbit[n]uril type molecular containers.

    Science.gov (United States)

    Hettiarachchi, Gaya; Nguyen, Duc; Wu, Jing; Lucas, Derick; Ma, Da; Isaacs, Lyle; Briken, Volker

    2010-05-06

    Many drug delivery systems are based on the ability of certain macrocyclic compounds - such as cyclodextrins (CDs) - to act as molecular containers for pharmaceutical agents in water. Indeed beta-CD and its derivatives have been widely used in the formulation of hydrophobic pharmaceuticals despite their poor abilities to act as a molecular container (e.g., weak binding (K(a)containers that bind to a variety of cationic and neutral species with high affinity (K(a)>10(4) M(-1)) and therefore show great promise as a drug delivery system. In this study we investigated the toxicology, uptake, and bioactivity of two cucurbit[n]urils (CB[5] and CB[7]) and three CB[n]-type containers (Pentamer 1, methyl hexamer 2, and phenyl hexamer 3). All five containers demonstrated high cell tolerance at concentrations of up to 1 mM in cell lines originating from kidney, liver or blood tissue using assays for metabolic activity and cytotoxicity. Furthermore, the CB[7] molecular container was efficiently internalized by macrophages indicating their potential for the intracellular delivery of drugs. Bioactivity assays showed that the first-line tuberculosis drug, ethambutol, was as efficient in treating mycobacteria infected macrophages when loaded into CB[7] as when given in the unbound form. This result suggests that CB[7]-bound drug molecules can be released from the container to find their intracellular target. Our study reveals very low toxicity of five members of the cucurbit[n]uril family of nanocontainers. It demonstrates the uptake of containers by cells and intracellular release of container-loaded drugs. These results provide initial proof-of-concept towards the use of CB[n] molecular containers as an advanced drug delivery system.

  10. Seletividade do herbicida fluazifop-p-butil para cucurbitáceas Selectivity of the herbicide fluazifop-p-buthyl for cucurbitaceae

    Directory of Open Access Journals (Sweden)

    R.A. Vidal

    2000-01-01

    Full Text Available Experimentos foram conduzidos em condições de casa de vegetação, com o objetivo de avaliar a seletividade do herbicida fluazifop-p-butil nas doses de 0, 94, 188, 376 e 752 g i.a. ha-1 para cinco espécies de cucurbitáceas (abobrinha, melancia, melão, moranga e pepino. Foi determinada a fitotoxicidade aos 14 dias após a aplicação dos tratamentos (DAT. Aos 20 DAT foram avaliadas a estatura, área foliar e matéria seca. O melão e o pepino mostraram sensibilidade ao fluazifop-p-butil na maior dose estudada, com maior intensidade no melão. Os resultados demonstraram que existe resposta a estes herbicidas mesmo dentro da classe Dicotiledoneae. Especula-se que essas respostas possam auxiliar no entendimento do completo mecanismo de ação desse herbicida.Experiments were conducted under greenhouse conditions to evaluate the selectivity of the herbicide fluazifop-p-buthyl at rates of 0, 94, 188 and 752 g a.i. ha-1 for five cucurbitaceous species (summer squash, watermelon, melon, pumpkin and cucumber. Plant injury at 14 days after treatments (DAT and plant size, leaf area and dry weight at 20 DAT were determined. Melon and cucumber were susceptible to fluazifop-p-buthyl at the highest rate with highest herbicide effect being observed on melon. These results indicated that responses to these herbicides occur, even in the Dicotiledonae class. These responses are thought to help understand the overall mechanism of action of this herbicide.

  11. Advanced Sulfur Cathode Enabled by Highly Crumpled Nitrogen-Doped Graphene Sheets for High-Energy-Density Lithium-Sulfur Batteries.

    Science.gov (United States)

    Song, Jiangxuan; Yu, Zhaoxin; Gordin, Mikhail L; Wang, Donghai

    2016-02-10

    Herein, we report a synthesis of highly crumpled nitrogen-doped graphene sheets with ultrahigh pore volume (5.4 cm(3)/g) via a simple thermally induced expansion strategy in absence of any templates. The wrinkled graphene sheets are interwoven rather than stacked, enabling rich nitrogen-containing active sites. Benefiting from the unique pore structure and nitrogen-doping induced strong polysulfide adsorption ability, lithium-sulfur battery cells using these wrinkled graphene sheets as both sulfur host and interlayer achieved a high capacity of ∼1000 mAh/g and exceptional cycling stability even at high sulfur content (≥80 wt %) and sulfur loading (5 mg sulfur/cm(2)). The high specific capacity together with the high sulfur loading push the areal capacity of sulfur cathodes to ∼5 mAh/cm(2), which is outstanding compared to other recently developed sulfur cathodes and ideal for practical applications.

  12. Host-Guest Interaction of Cucurbit[8]uril with N-(3-Aminopropyl)cyclohexylamine: Cyclohexyl Encapsulation Triggered Ternary Complex.

    Science.gov (United States)

    Xia, Yu; Wang, Chuan-Zeng; Tian, Mengkui; Tao, Zhu; Ni, Xin-Long; Prior, Timothy J; Redshaw, Carl

    2018-01-15

    The host-guest interaction of a series of cyclohexyl-appended guests with cucurbit[8]uril (Q[8]) was studied by ¹H NMR spectroscopy, isothermal titration calorimetry (ITC), and X-ray crystallography. The X-ray structure revealed that two cycloalkane moieties can be simultaneously encapsulated in the hydrophobic cavity of the Q[8] host to form a ternary complex for the first time.

  13. Host-Guest Interaction of Cucurbit[8]uril with N-(3-Aminopropylcyclohexylamine: Cyclohexyl Encapsulation Triggered Ternary Complex

    Directory of Open Access Journals (Sweden)

    Yu Xia

    2018-01-01

    Full Text Available The host-guest interaction of a series of cyclohexyl-appended guests with cucurbit[8]uril (Q[8] was studied by 1H NMR spectroscopy, isothermal titration calorimetry (ITC, and X-ray crystallography. The X-ray structure revealed that two cycloalkane moieties can be simultaneously encapsulated in the hydrophobic cavity of the Q[8] host to form a ternary complex for the first time.

  14. Predicting the risk of cucurbit downy mildew in the eastern United States using an integrated aerobiological model

    Science.gov (United States)

    Neufeld, K. N.; Keinath, A. P.; Gugino, B. K.; McGrath, M. T.; Sikora, E. J.; Miller, S. A.; Ivey, M. L.; Langston, D. B.; Dutta, B.; Keever, T.; Sims, A.; Ojiambo, P. S.

    2017-11-01

    Cucurbit downy mildew caused by the obligate oomycete, Pseudoperonospora cubensis, is considered one of the most economically important diseases of cucurbits worldwide. In the continental United States, the pathogen overwinters in southern Florida and along the coast of the Gulf of Mexico. Outbreaks of the disease in northern states occur annually via long-distance aerial transport of sporangia from infected source fields. An integrated aerobiological modeling system has been developed to predict the risk of disease occurrence and to facilitate timely use of fungicides for disease management. The forecasting system, which combines information on known inoculum sources, long-distance atmospheric spore transport and spore deposition modules, was tested to determine its accuracy in predicting risk of disease outbreak. Rainwater samples at disease monitoring sites in Alabama, Georgia, Louisiana, New York, North Carolina, Ohio, Pennsylvania and South Carolina were collected weekly from planting to the first appearance of symptoms at the field sites during the 2013, 2014, and 2015 growing seasons. A conventional PCR assay with primers specific to P. cubensis was used to detect the presence of sporangia in rain water samples. Disease forecasts were monitored and recorded for each site after each rain event until initial disease symptoms appeared. The pathogen was detected in 38 of the 187 rainwater samples collected during the study period. The forecasting system correctly predicted the risk of disease outbreak based on the presence of sporangia or appearance of initial disease symptoms with an overall accuracy rate of 66 and 75%, respectively. In addition, the probability that the forecasting system correctly classified the presence or absence of disease was ≥ 73%. The true skill statistic calculated based on the appearance of disease symptoms in cucurbit field plantings ranged from 0.42 to 0.58, indicating that the disease forecasting system had an acceptable to good

  15. Biocontrol agent Bacillus amyloliquefaciens LJ02 induces systemic resistance against cucurbits powdery mildew.

    Science.gov (United States)

    Li, Yunlong; Gu, Yilin; Li, Juan; Xu, Mingzhu; Wei, Qing; Wang, Yuanhong

    2015-01-01

    Powdery mildew is a fungal disease found in a wide range of plants and can significantly reduce crop yields. Bacterial strain LJ02 is a biocontrol agent (BCA) isolated from a greenhouse in Tianjin, China. In combination of morphological, physiological, biochemical and phylogenetic analyses, strain LJ02 was classified as a new member of Bacillus amyloliquefaciens. Greenhouse trials showed that LJ02 fermentation broth (LJ02FB) can effectively diminish the occurrence of cucurbits powdery mildew. When treated with LJ02FB, cucumber seedlings produced significantly elevated production of superoxide dismutase, peroxidase, polyphenol oxidase and phenylalanine ammonia lyase as compared to that of the control. We further confirmed that the production of free salicylic acid (SA) and expression of one pathogenesis-related (PR) gene PR-1 in cucumber leaves were markedly elevated after treating with LJ02FB, suggesting that SA-mediated defense response was stimulated. Moreover, LJ02FB-treated cucumber leaves could secrete resistance-related substances into rhizosphere that inhibit the germination of fungi spores and the growth of pathogens. Finally, we separated bacterium and its fermented substances to test their respective effects and found that both components have SA-inducing activity and bacterium plays major roles. Altogether, we identified a BCA against powdery mildew and its mode of action by inducing systemic resistance such as SA signaling pathway.

  16. Resistance to Cucurbit aphid-borne yellows virus in Melon Accession TGR-1551.

    Science.gov (United States)

    Kassem, Mona A; Gosalvez, Blanca; Garzo, Elisa; Fereres, Alberto; Gómez-Guillamón, Maria Luisa; Aranda, Miguel A

    2015-10-01

    The genetic control of resistance to Cucurbit aphid-borne yellows virus (CABYV; genus Polerovirus, family Luteoviridae) in the TGR-1551 melon accession was studied through agroinoculation of a genetic family obtained from the cross between this accession and the susceptible Spanish cultivar 'Bola de Oro'. Segregation analyses were consistent with the hypothesis that one dominant gene and at least two more modifier genes confer resistance; one of these additional genes is likely present in the susceptible parent 'Bola de Oro'. Local and systemic accumulation of the virus was analyzed in a time course experiment, showing that TGR-1551 resistance was expressed systemically as a significant reduction of virus accumulation compared with susceptible controls, but not locally in agroinoculated cotyledons. In aphid transmission experiments, CABYV inoculation by aphids was significantly reduced in TGR-1551 plants, although the virus was acquired at a similar rate from TGR-1551 as from susceptible plants. Results of feeding behavior studies using the DC electrical penetration graph technique suggested that viruliferous aphids can salivate and feed from the phloem of TGR-1551 plants and that the observed reduction in virus transmission efficiency is not related to reduced salivation by Aphis gossypii in phloem sieve elements. Since the virus is able to accumulate to normal levels in agroinoculated tissues, our results suggest that resistance of TGR-1551 plants to CABYV is related to impairment of virus movement or translocation after it reaches the phloem sieve elements.

  17. Flavylium network of chemical reactions in confined media: modulation of 3',4',7-trihydroxyflavilium reactions by host-guest interactions with cucurbit[7]uril.

    Science.gov (United States)

    Basílio, Nuno; Pina, Fernando

    2014-08-04

    In moderately acidic aqueous solutions, flavylium compounds undergo a pH-, and in some cases, light-dependent array of reversible chemical reactions. This network can be described as a single acid-base reaction involving a flavylium cation (acidic form) and a mixture of basic forms (quinoidal base, hemiketal and cis and trans chalcones). The apparent pK'a of the system and the relative mole fractions of the basic forms can be modulated by the interaction with cucurbit[7]uril. The system is studied by using (1) H NMR spectroscopy, UV/Vis spectroscopy, flash photolysis, and steady-state irradiation. Of all the network species, the flavylium cation possesses the highest affinity for cucurbit[7]uril. The rate of interconversion between flavylium cation and the basic species (where trans-chalcone is dominant) is approximately nine times lower inside the cucurbit[7]uril. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. El Amarilleo de las cucurbitáceas : diagnóstico y microscopía de las relaciones virus-planta y virus-vector

    OpenAIRE

    Rodrigo Villar, Gema

    2002-01-01

    L' ENGROGUIMENT DE LES CUCURBITÀCIES: DIAGNÓSTIC I MICROSCOPIA DE LES RELACIONS VIRUS-PLANTA I VIRUS-VECTOR La malaltia de l'engroguiment de les cucurbitàcies, de gran importància, en els cultius del sud-est espanyol, està produïda per dos Closteroviridae transmesos per mosques blanques, el virus del fals engroguiment de la remolatxa (BPYV) i el virus de l'engroguiment enanitzant de les cucurbitàcies (CYSDV). BPYV és transmès específicament i de forma semipersistent per Trialeurodes vaporario...

  19. Effects of Salinity Stress on Morphological and Physiological Characteristics of some Local Landrace and Inter specific Hybrids of Cucurbits Seedlings as Rootstocks

    Directory of Open Access Journals (Sweden)

    Ali Farhadi

    2017-12-01

    with 200 ml of saline water (0, 2 and 4 ds/m for 35 days. Excess solution was allowed to drain from the plants through drainage holes in the base of the pots. Hybrids of 152,426 and Trichosanthes cucumerina, Luffa cylindrical and Cucurbita pepo con. Pepo var. Styriaca was added. In the second phase measured shoot and root dry mass, SPAD index, relatively water content and seedling vigor index. Results and Discussion: the results showed that all parameters were significantly influenced by salinity except root: shoot ratio in Petri dish. Salinity stress reduced chlorophyll index (SPAD, relative water content in cucurbita leaves than control (without saline and also seeds germination, seedlings fresh mass and seedlings vigour by 51%, 53%, and 75 % respectively. .The shoot dry biomass of local landrace and inter specific hybrids in both experiment decreased linearly in response to increasing saline stress. Recorded data in Petri dish and plastic pot were significantly influenced by rootstock, whereas no significant difference was observed on germination rate and vigor index for plastic pot in greenhouse. The lowest seed germination percentage, seedling growth, vigor index and root: shoot ratio recorded on high saline concentration. NaCl threshold damage to cucurbits was evaluated 4 ds/m. Populations of C. maxima cv.Kermanshah and Shahreza, C.moschata cv. Isfahan and inters pecific hybrids Ferro, 909 and 910 were showed tolerant to salinity. It is proven that crop growth decreases with increasing saline stress (Rouphael, et al., 2012. Hybrids of C. moschata cv. Koshk, C. pepo cv. Koshk and Asgharabad, Lagenaria Siceraria, Es113 and Cucurbita pepo con. Pepo var. Styriaca were sensitive to saline stress. Kumar et al, (2008 also reported plant response to salinity depends on type of salt, salt concentration and plant genotype. Conclusions: Salinity stress adversely affect biomass and leaf water content of cucurbita. Our results indicated that local and hybrid cucurbit plants

  20. Influence of Mg doping on ZnO nanoparticles decorated on graphene oxide (GO) crumpled paper like sheet and its high photo catalytic performance under sunlight

    Science.gov (United States)

    Labhane, P. K.; Sonawane, S. H.; Sonawane, G. H.; Patil, S. P.; Huse, V. R.

    2018-03-01

    Mg doped ZnO nanoparticles decorated on graphene oxide (GO) sheets were synthesized by a wet impregnation method. The effect of Mg doping on ZnO and ZnO-GO composite has been evaluated by using x-ray diffraction (XRD), Williamson-Hall Plot (Wsbnd H Plot), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDX). The physical parameters of as-prepared samples were estimated by XRD data. FESEM and HR-TEM images showed the uniform distribution of nanoparticles on GO crumpled paper like sheet. Solar light photocatalytic activities of samples were evaluated spectrophotometrically by the degradation of p-nitrophenol (PNP) and indigo carmine (IC) solution. Mgsbnd ZnO decorated on GO sheets exhibit excellent catalytic efficiency compared to all other prepared samples under identical conditions, degrading PNP and IC nearly 99% within 60 min under sunlight. The effective degradation by Mgsbnd ZnO decorated on GO sheet would be due to extended solar light absorption, enhanced adsorptivity on the composite catalyst surface and efficient charge separation of photo-induced electrons. Finally, plausible mechanism was suggested with the help of scavengers study.

  1. Effect of Gamma Radiation on some Biological Performance of Cucurbit Fruit Fly Dacus ciliatus(Loew)(Diptera:Tephritidae)

    International Nuclear Information System (INIS)

    AL-Taweel, A. A.; AL-Shammary, A. J. M; Ahmed, R. F.

    2005-01-01

    The effect of gamma rays on males and females cucurbit fruit fly Dacus ciliatus (Loew) exposed as pupae at age of 5 days was investigated. The results revealed that the dose of 75 and 90 Gray caused complete sterility in females and males, respectively.Furthermore,the result of this study showed the exposing females and males as pupae to dose of 45 Gray or higher and mated either to gather or to unirradiated sex caused reduction in their production of the eggs and its percent of hatch. Finally results showed that all dosed of gamma rays had no effect on sex ratio of produced adults. (author)

  2. Genetic and virulence variability among Erwinia tracheiphila strains recovered from different cucurbit hosts.

    Science.gov (United States)

    Rojas, E Saalau; Dixon, P M; Batzer, J C; Gleason, M L

    2013-09-01

    The causal agent of cucurbit bacterial wilt, Erwinia tracheiphila, has a wide host range in the family Cucurbitaceae, including economically important crops such as muskmelon (Cucumis melo), cucumber (C. sativus), and squash (Cucurbita spp.). Genetic variability of 69 E. tracheiphila strains was investigated by repetitive-element polymerase chain reaction (rep-PCR) using BOXA1R and ERIC1-2 primers. Fingerprint profiles revealed significant variability associated with crop host; strains isolated from Cucumis spp. were clearly distinguishable from Cucurbita spp.-isolated strains regardless of geographic origin. Twelve E. tracheiphila strains isolated from muskmelon, cucumber, or summer squash were inoculated onto muskmelon and summer squash seedlings, followed by incubation in a growth chamber. Wilt symptoms were assessed over 3 weeks, strains were reisolated, and rep-PCR profiles were compared with the inoculated strains. Wilting occurred significantly faster when seedlings were inoculated with strains that originated from the same crop host genus (P<0.001). In the first run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon seedlings at a median of 7.8 and 5.6 days after inoculation (dai), respectively. Summer squash seedlings wilted 18.0, 15.7, and 5.7 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. In a second run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon at 7.0 and 6.9 dai, respectively, whereas summer squash seedlings wilted at 23.6, 29.0 and 9.0 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. Our results provide the first evidence of genetic diversity within E. tracheiphila and suggest that strain specificity is associated with plant host. This advance is a first step toward understanding the genetic and population structure of E. tracheiphila.

  3. Selección de rizobacterias por su antagonismo frente a microorganismos patógenos de cucurbitáceas /Screening of rhizobacteria for their antagonism against microbial pathogens of cucurbits.

    Directory of Open Access Journals (Sweden)

    Gilda Jiménez Montejo

    2014-04-01

    Full Text Available Resumen:El desarrollo de inoculantes microbianos a partir de aislamientos de rizobacterias con potencial para el control biológico de enfermedades de los cultivos agrícolas requiere de una rigurosa selección. Se obtuvieron aislamientos bacterianos de la rizosfera de papa (Solanum tuberosum L. y de maíz (Zea mays L. y de semillas de frijol (Phaseolus vulgaris L.. Las colonias que mostraron in vitro halos de inhibición de los patógenos de cucurbitáceas: Xanthomonas cucurbitae, Acidovorax avenae subsp. citrull y Fusarium oxysporum, se seleccionaron como antagonistas. A partir de las características morfológicas, fisiológicas y bioquímicas las cepas antagonistas F16/95 y Xph se identificaron con la especie Bacillus subtilis y la cepa 14A como Pseudomonas putida. Las pruebas presuntivas de producción de antibiocinas in vitro sugirieron modos de acción de las rizobacterias relacionados con antibiosis y competencia por el hierro mediante la producción de sideróforos. Los resultados indicaron el potencial de las cepas de rizobacterias antagonistas Bacillus subtilis (F16/95, Xph y Pesudomonas putida 14A para el control biológico de enfermedades de las cucurbitáceas./Abstract:

  4. FLOWERING LOCUS T Protein May Act as the Long-Distance Florigenic Signal in the Cucurbits[W

    Science.gov (United States)

    Lin, Ming-Kuem; Belanger, Helene; Lee, Young-Jin; Varkonyi-Gasic, Erika; Taoka, Ken-Ichiro; Miura, Eriko; Xoconostle-Cázares, Beatriz; Gendler, Karla; Jorgensen, Richard A.; Phinney, Brett; Lough, Tony J.; Lucas, William J.

    2007-01-01

    Cucurbita moschata, a cucurbit species responsive to inductive short-day (SD) photoperiods, and Zucchini yellow mosaic virus (ZYMV) were used to test whether long-distance movement of FLOWERING LOCUS T (FT) mRNA or FT is required for floral induction. Ectopic expression of FT by ZYMV was highly effective in mediating floral induction of long-day (LD)–treated plants. Moreover, the infection zone of ZYMV was far removed from floral meristems, suggesting that FT transcripts do not function as the florigenic signal in this system. Heterografting demonstrated efficient transmission of a florigenic signal from flowering Cucurbita maxima stocks to LD-grown C. moschata scions. Real-time RT-PCR performed on phloem sap collected from C. maxima stocks detected no FT transcripts, whereas mass spectrometry of phloem sap proteins revealed the presence of Cm-FTL1 and Cm-FTL2. Importantly, studies on LD- and SD-treated C. moschata plants established that Cmo-FTL1 and Cmo-FTL2 are regulated by photoperiod at the level of movement into the phloem and not by transcription. Finally, mass spectrometry of florally induced heterografted C. moschata scions revealed that C. maxima FT, but not FT mRNA, crossed the graft union in the phloem translocation stream. Collectively, these studies are consistent with FT functioning as a component of the florigenic signaling system in the cucurbits. PMID:17540715

  5. The formation of amino acid and dipeptide complexes with α-cyclodextrin and cucurbit[6]uril in aqueous solutions studied by titration calorimetry

    International Nuclear Information System (INIS)

    Buschmann, H.-J.; Schollmeyer, E.; Mutihac, L.

    2003-01-01

    The complex stabilities and the thermodynamic data for the complexation of α-cyclodextrin and cucurbit[6]uril with some amino acids (glycine, L-alanine, L-valine, L-phenylalanine, 6-amino hexanoic acid, 8-amino octanoic acid, 11-amino undecanoic acid) and dipeptides (glycyl-glycine, glycyl-L-valine, glycyl-L-leucine and glycyl-L-phenylalanine) have been determined in aqueous solution by calorimetric titrations. The complex formation with α-cyclodextrin is mainly favoured by entropic contributions due to the release of water molecules from the cavity of the ligand. The values of the reaction enthalpies are small with the exception of 11-amino undecanoic acid. In case of the ligand cucurbit[6]uril, ion-dipole interactions between the protonated amino groups of the amino acids and the carbonyl groups take place. By steric reasons these interactions are lowered for native amino acids because the polar carboxylic groups are always located outside the hydrophobic cavity of cucurbit[6]uril. The complexes of both ligands with dipeptides in water are characterised by hydrophobic interactions and in case of cucurbit[6]uril by additional ion-dipole interactions

  6. Systemic induction of NO-, redox- and cGMP signalling in the pumpkin extrafascicular phloem upon local leaf wounding

    Directory of Open Access Journals (Sweden)

    Frank eGaupels

    2016-02-01

    Full Text Available Cucurbits developed the unique extrafascicular phloem (EFP as a defensive structure against herbivorous animals. Mechanical leaf injury was previously shown to induce a systemic wound response in the EFP of pumpkin (Cucurbita maxima. Here, we demonstrate that the phloem antioxidant system and protein modifications by NO are strongly regulated during this process. Activities of the central antioxidant enzymes dehydroascorbate reductase, glutathione reductase and ascorbate reductase were rapidly down-regulated at 30 min with a second minimum at 24 h after wounding. As a consequence levels of total ascorbate and glutathione also decreased with similar bi-phasic kinetics. These results hint towards a wound-induced shift in the redox status of the EFP. Nitric oxide (NO is another important player in stress-induced redox signalling in plants. Therefore, we analysed NO-dependent protein modifications in the EFP. Six to 48 h after leaf damage total S-nitrosothiol content and protein S-nitrosylation were clearly reduced, which was contrasted by a pronounced increase in protein tyrosine nitration. Collectively, these findings suggest that NO-dependent S-nitrosylation turned into peroxynitrite-mediated protein nitration upon a stress-induced redox shift probably involving the accumulation of reactive oxygen species within the EFP. Using the biotin switch assay and anti-nitrotyrosine antibodies we identified 9 candidate S-nitrosylated and 6 candidate tyrosine-nitrated phloem proteins. The wound-responsive Phloem Protein 16-1 (PP16-1 and Cyclophilin 18 (CYP18 as well as the 26.5 kD isoform of Phloem Protein 2 (PP2 were amenable to both NO modifications and could represent important redox-sensors within the cucurbit EFP. We also found that leaf injury triggered the systemic accumulation of cyclic guanosine monophosphate (cGMP in the EFP and discuss the possible function of this second messenger in systemic NO and redox signalling within the EFP.

  7. Grid inhomogeneous solvation theory: hydration structure and thermodynamics of the miniature receptor cucurbit[7]uril.

    Science.gov (United States)

    Nguyen, Crystal N; Young, Tom Kurtzman; Gilson, Michael K

    2012-07-28

    The displacement of perturbed water upon binding is believed to play a critical role in the thermodynamics of biomolecular recognition, but it is nontrivial to unambiguously define and answer questions about this process. We address this issue by introducing grid inhomogeneous solvation theory (GIST), which discretizes the equations of inhomogeneous solvation theory (IST) onto a three-dimensional grid situated in the region of interest around a solute molecule or complex. Snapshots from explicit solvent simulations are used to estimate localized solvation entropies, energies, and free energies associated with the grid boxes, or voxels, and properly summing these thermodynamic quantities over voxels yields information about hydration thermodynamics. GIST thus provides a smoothly varying representation of water properties as a function of position, rather than focusing on hydration sites where solvent is present at high density. It therefore accounts for full or partial displacement of water from sites that are highly occupied by water, as well as for partly occupied and water-depleted regions around the solute. GIST can also provide a well-defined estimate of the solvation free energy and therefore enables a rigorous end-states analysis of binding. For example, one may not only use a first GIST calculation to project the thermodynamic consequences of displacing water from the surface of a receptor by a ligand, but also account, in a second GIST calculation, for the thermodynamics of subsequent solvent reorganization around the bound complex. In the present study, a first GIST analysis of the molecular host cucurbit[7]uril is found to yield a rich picture of hydration structure and thermodynamics in and around this miniature receptor. One of the most striking results is the observation of a toroidal region of high water density at the center of the host's nonpolar cavity. Despite its high density, the water in this toroidal region is disfavored energetically and

  8. Seagrass leaf element content

    NARCIS (Netherlands)

    Vonk, J.A.; Smulders, Fee O.H.; Christianen, Marjolijn J.A.; Govers, Laura L.

    2017-01-01

    Knowledge on the role of seagrass leaf elements and in particular micronutrients and their ranges is limited. We present a global database, consisting of 1126 unique leaf values for ten elements, obtained from literature and unpublished data, spanning 25 different seagrass species from 28 countries.

  9. Chiral Binaphthylbis(4,4'-Bipyridin-1-Ium)/Cucurbit[8]Uril Supramolecular System and Its Induced Circularly Polarized Luminescence.

    Science.gov (United States)

    Chen, Xu-Man; Chen, Yong; Liang, Lu; Liu, Qiu-Jun; Liu, Yu

    2018-05-01

    Circularly polarized luminescence (CPL) induced by host-guest complexation remains a challenge in supramolecular chemistry. Herein, a couple of CPL-silent enantiomeric guest binaphthylbis(4,4'-bipyridinium) salts can emit obvious CPL in the presence of cucurbit[8]uril in aqueous media, due to the restriction of molecular rotation limitation effect. Such CPL can be reversibly adjusted by the addition of acid and base. Furthermore, the resultant supramolecular systems can interact with DNA, accompanied by the morphological conversion from branched supramolecular nanowires to exfoliated nanowires, which can enable to the exploration of such supramolecular systems as DNA markers by CPL signals. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Toward a versatile toolbox for cucurbit[n]uril-based supramolecular hydrogel networks through in situ polymerization.

    Science.gov (United States)

    Liu, Ji; Soo Yun Tan, Cindy; Lan, Yang; Scherman, Oren A

    2017-09-15

    The success of exploiting cucurbit[ n ]uril (CB[ n ])-based molecular recognition in self-assembled systems has sparked a tremendous interest in polymer and materials chemistry. In this study, polymerization in the presence of host-guest complexes is applied as a modular synthetic approach toward a diverse set of CB[8]-based supramolecular hydrogels with desirable properties, such as mechanical strength, toughness, energy dissipation, self-healing, and shear-thinning. A range of vinyl monomers, including acrylamide-, acrylate-, and imidazolium-based hydrophilic monomers, could be easily incorporated as the polymer backbones, leading to a library of CB[8] hydrogel networks. This versatile strategy explores new horizons for the construction of supramolecular hydrogel networks and materials with emergent properties in wearable and self-healable electronic devices, sensors, and structural biomaterials. © 2017 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 3105-3109.

  11. Emission of hydrogen sulfide by leaf tissue in response to L-cysteine

    International Nuclear Information System (INIS)

    Sekiya, J.; Schmidt, A.; Wilson, L.G.; Filner, P.

    1982-01-01

    Leaf discs and detached leaves exposed to L-cysteine emitted a volatile sulfur compound which was proven by gas chromatography to be H 2 S. This phenomenon was demonstrated in all nine species tested (Cucumis sativus, Cucurbita pepo, Nicotiana tabacum, Coleus blumei, Beta vulgaris, Phaseolus vulgaris, Medicago sativa, Hordeum vulgare, and Gossypium hirsutum). The emission of volatile sulfur by cucumber leaves occurred in the dark at a similar rate to that in the light. The emission of leaf discs reached the maximal rate, more than 40 picomoles per minute per square centimeter, 2 to 4 hours after starting exposure to L-cysteine; then it decreased. In the case of detached leaves, the maximum occurred 5 to 10 h after starting exposure. The average emission rate of H 2 S during the first 4 hours from leaf discs of cucurbits in response to 10 millimolar L-cysteine, was usually more than 40 picomoles per minute per square centimeter, i.e. 0.24 micromoles per hour per square decimeter. Leaf discs exposed to 1 millimolar L-cysteine emitted only 2% as much as did the discs exposed to 10 millimolar L-cysteine. The emission from leaf discs and from detached leaves lasted for at least 5 and 15 hours, respectively. However, several hours after the maximal emission, injury of the leaves, manifested as chlorosis, was evident. H 2 S emission was a specific consequence of exposure to L-cysteine; neither D-cysteine nor L-cysteine elicited H 2 S emission. Aminooxyacetic acid, an inhibitor of pyridoxal phosphate dependent enzymes, inhibited the emission. In a cell free system from cucumber leaves, H 2 S formation and its release occurred in response to L-cysteine. Feeding experiments with [ 35 S]t-cysteine showed that most of the sulfur in H 2 S was derived from sulfur in the L-cysteine supplied

  12. The use of UV radiation to control architecture of cucurbits transplants

    International Nuclear Information System (INIS)

    Bartolomeo, L.; Diara, C.; Bertram, L.

    2003-01-01

    UV treatments of plug transplants of muskmelon, cucumber and squash were performed in greenhouse to control seedling height and improve their adaptation to outdoor conditions. UVB sources, Philips TL12-40W, were placed 0.6 m above the seedlings. UV treatments were repeated daily, 0.5-2 h/day [4.3 - 25.8 kJm*[-2) d*[-1)] in the middle of the night, for one week and started when cotyledons emerged from the soil. Plant height, leaf area and stem and leaf dry weights were significantly lowered by UV treatments in all species investigated. Cucumber was the most and muskmelon the least sensitive to the UV treatments [it

  13. Assessment of the genetic and phenotypic diversity among rhizogenic Agrobacterium biovar 1 strains infecting solanaceous and cucurbit crops.

    Science.gov (United States)

    Bosmans, Lien; Álvarez-Pérez, Sergio; Moerkens, Rob; Wittemans, Lieve; Van Calenberge, Bart; Kerckhove, Stefan Van; Paeleman, Anneleen; De Mot, René; Rediers, Hans; Lievens, Bart

    2015-08-01

    Rhizogenic Agrobacterium biovar 1 strains have been found to cause extensive root proliferation on hydroponically grown Cucurbitaceae and Solanaceae crops, resulting in substantial economic losses. As these agrobacteria live under similar ecological conditions, infecting a limited number of crops, it may be hypothesized that genetic and phenotypic variation among such strains is relatively low. In this study we assessed the phenotypic diversity as well as the phylogenetic and evolutionary relationships of several rhizogenic Agrobacterium biovar 1 strains from cucurbit and solanaceous crops. A collection of 41 isolates was subjected to a number of phenotypic assays and characterized by MLSA targeting four housekeeping genes (16S rRNA gene, recA, rpoB and trpE) and two loci from the root-inducing Ri-plasmid (part of rolB and virD2). Besides phenotypic variation, remarkable genotypic diversity was observed, especially for some chromosomal loci such as trpE. In contrast, genetic diversity was lower for the plasmid-borne loci, indicating that the studied chromosomal housekeeping genes and Ri-plasmid-borne loci might not exhibit the same evolutionary history. Furthermore, phylogenetic and network analyses and several recombination tests suggested that recombination could be contributing in some extent to the evolutionary dynamics of rhizogenic Agrobacterium populations. Finally, a genomospecies-level identification analysis revealed that at least four genomospecies may occur on cucurbit and tomato crops (G1, G3, G8 and G9). Together, this study gives a first glimpse at the genetic and phenotypic diversity within this economically important plant pathogenic bacterium. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Developing electrodes chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA) by voltammetry

    International Nuclear Information System (INIS)

    Tadini, Maraine Catarina; Balbino, Marco Antonio; Eleoterio, Izabel Cristina; Siqueirade Oliveira, Laura; Dias, Luis Gustavo; Jean-François Demets, Grégoire; Firmino de Oliveira, Marcelo

    2014-01-01

    Graphical abstract: - Highlights: • A new stand in forensic chemistry. • Voltammetric method for the determination of MDMA in seized samples. • A new voltammetric sensor for MDMA. - Abstract: This study aimed to develop an electrode chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA), the main active principle of ecstasy samples, by voltammetry. We modified the electrode surface with a film containing cucurbit[6]uril, Nafion, and methanol, using the dip coating or the spin coating technique. During analysis, we employed an electrochemical cell with a conventional three-electrode system and KCl solution (0.1 mol L −1 ) as the supporting electrolyte. We conducted cyclic voltammetry at concentrations ranging from 4.2 × 10 −6 to 4.8 × 10 −5 mol L −1 . We also accomplished scanning electron microscopy, to investigate the structural behavior of the film that originated on the electrode surface. We obtained the following results when we used dip coating to prepare the modified electrode: standard deviation (SD) = 0.024 μA, limit of detection (LOD) = 3.5 μmol L −1 , limit of quantification (LOQ) = 11.7 μmol L −1 , and amperometric sensitivity (m) = 20.9 × 10 3 μA L mol −1 . As for spin coating, we obtained SD = 0.024 μA, LOD = 2.7 μmol L −1 , LOQ = 9.1 μmol L −1 and m = 25.9 × 10 3 μA mol L −1 . These are very promising data: the modified electrode is more sensitive than the conventional glassy carbon electrode under the studied experimental conditions

  15. Patterns of species richness and diversity of insects associated with cucurbit fruits in the southern part of Cameroon.

    Science.gov (United States)

    Mokam, Didi Gaëlle; Djiéto-Lordon, Champlain; Bilong Bilong, Charles-Félix

    2014-01-01

    Patterns of species diversity and community structure of insects associated with fruits of domesticated cucurbits were investigated from January 2009 to 2011 in three localities from two agroecological zones in the southern part of Cameroon. Rarefaction curves combined with nonparametric estimators of species richness were used to extrapolate species richness beyond our own data. Sampling efforts of over 92% were reached in each of the three study localities. Data collected revealed a total of 66 insect morphospecies belonging to 37 families and five orders, identified from a set of 57,510 insects. The orders Diptera (especially Tephritidae and Lonchaeidae) and Hymenoptera (mainly Braconidae and Eulophidae) were the most important, in terms of both abundance and species richness on the one hand, and effects on agronomic performance on the other. Values for both the species diversity (Shannon and Simpson) and the species richness indices (Margalef and Berger-Parker) calculated showed that the insect communities were species-rich but dominated, all to a similar extent, by five main species (including four fruit fly species and one parasitoid). Species abundance distributions in these communities ranged from the Zipf-Mandelbrot to Mandelbrot models. The communities are structured as tritrophic networks, including cucurbit fruits, fruit-feeding species (fruit flies) and carnivorous species (parasitoids). Within the guild of the parasitoids, about 30% of species, despite their low abundance, may potentially be of use in biological control of important pests. Our field data contribute in important ways to basic knowledge of biodiversity patterns in agrosystems and constitute baseline data for the planned implementation of biological control in Integrated Pest Management. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  16. A Nexus between Theory and Experiment: Non-Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]urilGuest Binding Interactions

    Czech Academy of Sciences Publication Activity Database

    Hostaš, Jiří; Sigwalt, D.; Šekutor, M.; Ajani, Haresh; Dubecký, M.; Řezáč, Jan; Zavalij, P. Y.; Cao, L.; Wohlschlager, Ch.; Mlinaric-Majerski, K.; Isaacs, L.; Glaser, R.; Hobza, Pavel

    2016-01-01

    Roč. 22, č. 48 (2016), s. 17226-17238 ISSN 0947-6539 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388963 Keywords : adamantane-/diamantane-skeleton guests * biomimetic complexes * BLYP-D3 quantum mechanical calculations * cucurbit[n]uril * host-guest complexes * primary ammonium loops Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.317, year: 2016

  17. Geometric leaf placement strategies

    International Nuclear Information System (INIS)

    Fenwick, J D; Temple, S W P; Clements, R W; Lawrence, G P; Mayles, H M O; Mayles, W P M

    2004-01-01

    Geometric leaf placement strategies for multileaf collimators (MLCs) typically involve the expansion of the beam's-eye-view contour of a target by a uniform MLC margin, followed by movement of the leaves until some point on each leaf end touches the expanded contour. Film-based dose-distribution measurements have been made to determine appropriate MLC margins-characterized through an index d 90 -for multileaves set using one particular strategy to straight lines lying at various angles to the direction of leaf travel. Simple trigonometric relationships exist between different geometric leaf placement strategies and are used to generalize the results of the film work into d 90 values for several different strategies. Measured d 90 values vary both with angle and leaf placement strategy. A model has been derived that explains and describes quite well the observed variations of d 90 with angle. The d 90 angular variations of the strategies studied differ substantially, and geometric and dosimetric reasoning suggests that the best strategy is the one with the least angular variation. Using this criterion, the best straightforwardly implementable strategy studied is a 'touch circle' approach for which semicircles are imagined to be inscribed within leaf ends, the leaves being moved until the semicircles just touch the expanded target outline

  18. An accurate, specific, sensitive, high-throughput method based on a microsphere immunoassay for multiplex detection of three viruses and bacterial fruit blotch bacterium in cucurbits.

    Science.gov (United States)

    Charlermroj, Ratthaphol; Makornwattana, Manlika; Himananto, Orawan; Seepiban, Channarong; Phuengwas, Sudtida; Warin, Nuchnard; Gajanandana, Oraprapai; Karoonuthaisiri, Nitsara

    2017-09-01

    To employ a microsphere immunoassay (MIA) to simultaneously detect multiple plant pathogens (potyviruses, Watermelon silver mottle virus, Melon yellow spot virus, and Acidovorax avenae subsp. citrulli) in actual plant samples, several factors need to be optimized and rigorously validated. Here, a simple extraction method using a single extraction buffer was successfully selected to detect the four pathogens in various cucurbit samples (cucumber, cantaloupe, melon, and watermelon). The extraction method and assay performance were validated with inoculated and field cucurbit samples. The MIA showed 98-99% relative accuracy, 97-100% relative specificity and 92-100% relative sensitivity when compared to commercial ELISA kits and reverse transcription PCR. In addition, the MIA was also able to accurately detect multiple-infected field samples. The results demonstrate that one common extraction method for all tested cucurbit samples could be applied to detect multiple pathogens; avoiding the need for multiple protocols to be employed. This multiplex method can therefore be instrumental for high-throughput screening of multiple plant pathogens with many advantages such as a shorter assay time (2.5h) with single assay format, a lower cost of detection ($5 vs $19.7 for 4 pathogens/sample) and less labor requirement. Its multiplex capacity can also be expanded to detect up to 50 different pathogens upon the availability of specific antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Co-grinding Effect on Crystalline Zaltoprofen with β-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    Science.gov (United States)

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-04-01

    This work aimed to investigate the co-grinding effects of β-cyclodextrin (β-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline ZPF. Co-ground dispersions exhibited completely amorphous states and elicited a significant reinforcing effect on drug solubility. UV-vis spectroscopy, XRPD, FT-IR, DSC, ssNMR, and molecular docking demonstrated the interactions in the amorphous product. Hardness tests on blank tablets with different β-CD and CB[7] contents suggested the addition of β-CD or CB[7] could enhance the compressibility of the powder mixture. Disintegration tests showed that CB[7] could efficiently shorten the disintegrating time. Dissolution tests indicated that β-CD and CB[7] could accelerate the drug dissolution rate via different mechanisms. Specifically, CB[7] could accelerate the dissolution rate by improving disintegration and β-CD showed a distinct advantage in solubility enhancement. Based on the comparative study on β-CD and CB[7] for tablet formulation combined with co-grinding, we found that CB[7] could be considered a promising drug delivery, which acted as a disintegrant.

  20. Co-grinding Effect on Crystalline Zaltoprofen with β-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

    Science.gov (United States)

    Li, Shanshan; Lin, Xiang; Xu, Kailin; He, Jiawei; Yang, Hongqin; Li, Hui

    2017-01-01

    This work aimed to investigate the co-grinding effects of β-cyclodextrin (β-CD) and cucurbit[7]uril (CB[7]) on crystalline zaltoprofen (ZPF) in tablet formulation. Crystalline ZPF was prepared through anti-solvent recrystallization and fully analyzed through single-crystal X-ray diffraction. Co-ground dispersions and mono-ground ZPF were prepared using a ball grinding process. Results revealed that mono-ground ZPF slightly affected the solid state, solubility, and dissolution of crystalline ZPF. Co-ground dispersions exhibited completely amorphous states and elicited a significant reinforcing effect on drug solubility. UV-vis spectroscopy, XRPD, FT-IR, DSC, ssNMR, and molecular docking demonstrated the interactions in the amorphous product. Hardness tests on blank tablets with different β-CD and CB[7] contents suggested the addition of β-CD or CB[7] could enhance the compressibility of the powder mixture. Disintegration tests showed that CB[7] could efficiently shorten the disintegrating time. Dissolution tests indicated that β-CD and CB[7] could accelerate the drug dissolution rate via different mechanisms. Specifically, CB[7] could accelerate the dissolution rate by improving disintegration and β-CD showed a distinct advantage in solubility enhancement. Based on the comparative study on β-CD and CB[7] for tablet formulation combined with co-grinding, we found that CB[7] could be considered a promising drug delivery, which acted as a disintegrant. PMID:28368030

  1. PH responsive self-assembly of cucurbit[7]urils and polystyrene-block- polyvinylpyridine micelles for hydrophobic drug delivery

    KAUST Repository

    Moosa, Basem; Mashat, A.; Li, W.; Fhayli, K.; Khashab, Niveen M.

    2013-01-01

    Polystyrene-block-polyvinylpyridine (PS-b-P4VP) polypseudorotaxanes with cucurbit[7]urils (CB[7]) were prepared from water soluble PS-b-P4VPH+ polymer and CB[7] in aqueous solution at room temperature. At acidic and neutral pH, the pyridinium block of PS-b-P4VP is protonated (PS-b-P4VPH +) pushing CB[7] to preferably host the P4VP block. At basic pH (pH 8), P4VP is not charged and thus is not able to strongly complex CB[7]. This phenomenon was verified further by monitoring the release of pyrene, a hydrophobic cargo model, from a PS-b-P4VPH+/CB[7] micellar membrane. Release study of UV active pyrene from the membrane at different pH values revealed that the system is only operational under basic conditions and that the host-guest interaction of CB[7] with P4VPH+ significantly slows down cargo release.

  2. Genetic diversity and potential vectors and reservoirs of Cucurbit aphid-borne yellows virus in southeastern Spain.

    Science.gov (United States)

    Kassem, Mona A; Juarez, Miguel; Gómez, Pedro; Mengual, Carmen M; Sempere, Raquel N; Plaza, María; Elena, Santiago F; Moreno, Aranzazu; Fereres, Alberto; Aranda, Miguel A

    2013-11-01

    The genetic variability of a Cucurbit aphid-borne yellows virus (CABYV) (genus Polerovirus, family Luteoviridae) population was evaluated by determining the nucleotide sequences of two genomic regions of CABYV isolates collected in open-field melon and squash crops during three consecutive years in Murcia (southeastern Spain). A phylogenetic analysis showed the existence of two major clades. The sequences did not cluster according to host, year, or locality of collection, and nucleotide similarities among isolates were 97 to 100 and 94 to 97% within and between clades, respectively. The ratio of nonsynonymous to synonymous nucleotide substitutions reflected that all open reading frames have been under purifying selection. Estimates of the population's genetic diversity were of the same magnitude as those previously reported for other plant virus populations sampled at larger spatial and temporal scales, suggesting either the presence of CABYV in the surveyed area long before it was first described, multiple introductions, or a particularly rapid diversification. We also determined the full-length sequences of three isolates, identifying the occurrence and location of recombination events along the CABYV genome. Furthermore, our field surveys indicated that Aphis gossypii was the major vector species of CABYV and the most abundant aphid species colonizing melon fields in the Murcia (Spain) region. Our surveys also suggested the importance of the weed species Ecballium elaterium as an alternative host and potential virus reservoir.

  3. Leaf-IT: An Android application for measuring leaf area.

    Science.gov (United States)

    Schrader, Julian; Pillar, Giso; Kreft, Holger

    2017-11-01

    The use of plant functional traits has become increasingly popular in ecological studies because plant functional traits help to understand key ecological processes in plant species and communities. This also includes changes in diversity, inter- and intraspecific interactions, and relationships of species at different spatiotemporal scales. Leaf traits are among the most important traits as they describe key dimensions of a plant's life history strategy. Further, leaf area is a key parameter with relevance for other traits such as specific leaf area, which in turn correlates with leaf chemical composition, photosynthetic rate, leaf longevity, and carbon investment. Measuring leaf area usually involves the use of scanners and commercial software and can be difficult under field conditions. We present Leaf-IT, a new smartphone application for measuring leaf area and other trait-related areas. Leaf-IT is free, designed for scientific purposes, and runs on Android 4 or higher. We tested the precision and accuracy using objects with standardized area and compared the area measurements of real leaves with the well-established, commercial software WinFOLIA using the Altman-Bland method. Area measurements of standardized objects show that Leaf-IT measures area with high accuracy and precision. Area measurements with Leaf-IT of real leaves are comparable to those of WinFOLIA. Leaf-IT is an easy-to-use application running on a wide range of smartphones. That increases the portability and use of Leaf-IT and makes it possible to measure leaf area under field conditions typical for remote locations. Its high accuracy and precision are similar to WinFOLIA. Currently, its main limitation is margin detection of damaged leaves or complex leaf morphologies.

  4. A combined molecular dynamics simulation and quantum mechanics study on mercaptopurine interaction with the cucurbit [6,7] urils: Analysis of electronic structure.

    Science.gov (United States)

    Zaboli, Maryam; Raissi, Heidar

    2018-01-05

    In the current study, the probability of complex formation between mercaptopurine drug with cucurbit[6]urils and cucurbit[7]urils has been investigated. The calculations for geometry optimization of complexes have been carried out by means of DFT (B3LYP), DFT-D (B3LYP-D) and M06-2X methods. The Atoms In Molecules (AIM), Natural Bond Orbital (NBO), NMR, the density of states (DOSs) and frontier molecular orbital (MO) analyses have been done on the inclusion complexes. In addition, the UV-Vis spectra of the first eight states have been obtained by CAM-B3LYP/TD-DFT calculation. The obtained results of the complexation process reveal that CB[7]-DRG complexes are more favorable than that of CB[6]-DRG interactions. Furthermore, our theoretical results show that configurations III and I are the most stable configurations related to the CB[6]/DRG and CB[7]/DRG interactions, respectively. The positive ∇ 2 ρ (r) and HC values at the bond critical points indicate that exist the weak H-bonds between CB[6] and CB[7] with H atoms of the drug molecule. The obtained negative binding energy values of CB[7]-DRG interaction in solution phase show the stability of these complexes in the aqueous medium. Also, all of the observed parameters of molecular dynamics simulation such as the number of contacts, hydrogen bonding, center-of-mass distance and van der Waals energy values confirm the encapsulation of mercaptopurine molecule inside the cucurbit[7]urils cavity at about 3.2ns. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Synthesis of honeycomb-like palladium nanostructures by using cucurbit[7]uril and their catalytic activities for reduction of 4-nitrophenol

    Energy Technology Data Exchange (ETDEWEB)

    Premkumar, Thathan [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); The University College/Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Geckeler, Kurt E., E-mail: keg@gist.ac.kr [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics (WCU), Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2014-12-15

    An eco-friendly one-pot method to synthesize self-assembled palladium nanoclusters using a macrocycle, namely cucurbit[7]uril, in the alkaline medium without employing any special reducing or capping agents and/or external energy at room temperature is described. This greener approach, which utilizes water as a benign solvent and biocompatible cucurbit[7]uril as both reducing and protecting agents, can be applied to synthesize other noble metal nanoparticles such as gold, silver, and platinum. Owing to unique structural arrangement of cucurbit[7]uril, it was possible to prepare palladium nanoclusters of honeycomb-like structure irrespective of the reaction conditions. The honeycomb-like palladium nanoclusters were characterized using transmission electron microscopy (TEM), higher-resolution TEM (HR-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV–vis, and FT-IR spectroscopy. Significantly, the synthesized palladium nanoclusters exhibited catalytic activity for the reduction reaction of 4-nitrophenol at room temperature. The approach launched here is easy, green, and user-friendly in contrast to the conventional techniques using polymers or surfactants and harsh reductants. - Highlights: • A simple and one-pot method to synthesis palladium nanostructures with honey-comb like structure. • The strategy established here does not require any harsh and toxic reducing agents. • It has a potential to be a general method for the synthesis of metal nanoparticles in water medium. • Palladium nanoclusters can be used as catalyst for the reduction reaction of 4-nitrophenol. • This system makes a novel platform for industrial and biomedical applications.

  6. Simultaneous detection of Acidovorax avenae subsp. citrulli and Didymella bryoniae in cucurbit seedlots using magnetic capture hybridization and real-time polymerase chain reaction.

    Science.gov (United States)

    Ha, Y; Fessehaie, A; Ling, K S; Wechter, W P; Keinath, A P; Walcott, R R

    2009-06-01

    To improve the simultaneous detection of two pathogens in cucurbit seed, a combination of magnetic capture hybridization (MCH) and multiplex real-time polymerase chain reaction (PCR) was developed. Single-stranded DNA hybridization capture probes targeting DNA of Acidovorax avenae subsp. citrulli, causal agent of bacterial fruit blotch, and Didymella bryoniae, causal agent of gummy stem blight, were covalently attached to magnetic particles and used to selectively concentrate template DNA from cucurbit seed samples. Sequestered template DNAs were subsequently amplified by multiplex real-time PCR using pathogen-specific TaqMan PCR assays. The MCH multiplex real-time PCR assay displayed a detection threshold of A. avenae subsp. citrulli at 10 CFU/ml and D. bryoniae at 10(5) conidia/ml in mixtures of pure cultures of the two pathogens, which was 10-fold more sensitive than the direct real-time PCR assays for the two pathogens separately. Although the direct real-time PCR assay displayed a detection threshold for A. avenae subsp. citrulli DNA of 100 fg/microl in 25% (1/4 samples) of the samples assayed, MCH real-time PCR demonstrated 100% detection frequency (4/4 samples) at the same DNA concentration. MCH did not improve detection sensitivity for D. bryoniae relative to direct real-time PCR using conidial suspensions or seed washes from D. bryoniae-infested cucurbit seed. However, MCH real-time PCR facilitated detection of both target pathogens in watermelon and melon seed samples (n = 5,000 seeds/sample) in which 0.02% of the seed were infested with A. avenae subsp. citrulli and 0.02% were infested with D. bryoniae.

  7. A combined molecular dynamics simulation and quantum mechanics study on mercaptopurine interaction with the cucurbit [6,7] urils: Analysis of electronic structure

    Science.gov (United States)

    Zaboli, Maryam; Raissi, Heidar

    2018-01-01

    In the current study, the probability of complex formation between mercaptopurine drug with cucurbit[6]urils and cucurbit[7]urils has been investigated. The calculations for geometry optimization of complexes have been carried out by means of DFT (B3LYP), DFT-D (B3LYP-D) and M06-2X methods. The Atoms In Molecules (AIM), Natural Bond Orbital (NBO), NMR, the density of states (DOSs) and frontier molecular orbital (MO) analyses have been done on the inclusion complexes. In addition, the UV-Vis spectra of the first eight states have been obtained by CAM-B3LYP/TD-DFT calculation. The obtained results of the complexation process reveal that CB[7]-DRG complexes are more favorable than that of CB[6]-DRG interactions. Furthermore, our theoretical results show that configurations III and I are the most stable configurations related to the CB[6]/DRG and CB[7]/DRG interactions, respectively. The positive ∇2ρ(r) and HC values at the bond critical points indicate that exist the weak H-bonds between CB[6] and CB[7] with H atoms of the drug molecule. The obtained negative binding energy values of CB[7]-DRG interaction in solution phase show the stability of these complexes in the aqueous medium. Also, all of the observed parameters of molecular dynamics simulation such as the number of contacts, hydrogen bonding, center-of-mass distance and van der Waals energy values confirm the encapsulation of mercaptopurine molecule inside the cucurbit[7]urils cavity at about 3.2 ns.

  8. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  9. A rapid inoculation technique for assessing pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis on Cucurbits

    Science.gov (United States)

    Freeman, S.; Rodriguez, R.J.

    1993-01-01

    A continuous-dip inoculation technique for rapid assessment of pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis was developed. The method, adapted from a similar procedure for determining pathogenicity of Colletotrichum magna (causal agent of anthracnose of cucurbits), involves constant exposure of seedlings and cuttings (seedlings with root systems excised) of watermelon and muskmelon to conidial suspensions contained in small scintillation vials. Disease development in intact seedlings corresponded well to disease responses observed with the standard root-dip inoculation/pot assay. The continuous-dip inoculation technique resulted in rapid disease development, with 50% of watermelon cuttings dying after 4–6 days of exposure to F. o. niveum. A mortality of 30% also was observed in watermelon cuttings exposed to conidia of F. o. melonis, as opposed to only a 0–2.5% mortality in seedlings with intact roots. Disease response was similar with muskmelon seedlings and cuttings continuously dip-inoculated with F. o. melonis isolates. However, no disease symptoms were observed in muskmelon seedlings or cuttings inoculated with F. o. niveum. Four nonpathogenic isolates of F. oxysporum did not cause disease symptoms in either watermelon or muskmelon cuttings and seedlings when assayed by this technique. The proposed method enables a rapid screening of pathogenicity and requires less time, labor, and greenhouse space than the standard root-dip inoculation/pot assay. The reliability of the continuous-dip inoculation technique is limited, however, to exposure of intact seedlings at a concentration of 1 × 106conidia per milliliter; the method is not accurate at this range for excised seedlings.

  10. Cucurbit[8]uril-Containing Multilayer Films for the Photocontrolled Binding and Release of a Guest Molecule.

    Science.gov (United States)

    Nicolas, Henning; Yuan, Bin; Zhang, Xi; Schönhoff, Monika

    2016-03-15

    The powerful host-guest chemistry of cucurbit[8]uril (CB[8]) was employed to obtain photoresponsive polyelectrolyte multilayer films for the reversible and photocontrolled binding and release of an organic guest molecule. For this purpose, we designed and synthesized a polyelectrolyte with azobenzene side groups. Then, CB[8] was associated with the azo side group to obtain a supramolecular host-guest complex that was further used as building block in order to prepare photoresponsive and CB[8]-containing polyelectrolyte multilayer films. Ultraviolet spectroscopy and a dissipative quartz crystal microbalance are employed to monitor the formation of the host-guest complex and the layer-by-layer self-assembly of the multilayer films, respectively. We demonstrate that the photoresponsive properties of the azo side groups are maintained before and after host-guest complexation with CB[8] in solution and within the multilayer films, respectively. A guest molecule was then specifically included as second binding partner into the CB[8]-containing multilayer films. Subsequently, the release of the guest was performed by UV light irradiation due to the trans-cis isomerization of the adjacent azo side groups. Re-isomerization of the azo side groups was achieved by VIS light irradiation and enabled the rebinding of the guest into CB[8]. Finally, we demonstrate that the photocontrolled binding and release within CB[8]-containing multilayer films can reliably and reversibly be performed over a period of more than 2 weeks with constant binding efficiency. Therefore, we expect such novel type of photosensitive films to have promising future applications in the field of stimuli-responsive nanomaterials.

  11. Biomass, virus concentration, and symptomatology of cucurbits infected by mild and severe strains of Papaya ringspot virus

    Directory of Open Access Journals (Sweden)

    Pacheco Davi Andrade

    2003-01-01

    Full Text Available Pre-immunization with mild strains of Papaya ringspot virus - type W (PRWV-W has allowed the mosaic disease to be controlled in different cucurbit species, with increases in marketable fruit yield. The objective of this study was to compare virus concentration, biomass and symptomatology of 'Caserta' zucchini squash, 'Menina Brasileira' long-neck squash and 'Crimson Sweet' watermelon plants infected by three mild strains and one severe strain of PRSV-W. Plants were inoculated at the cotyledonary stage, under greenhouse conditions, sampled at 7, 14, 21, 28 and 35 days after inoculation (DAI, and analyzed by PTA-ELISA. The severity of the symptoms was scored according to a scale from 1 to 5, and the fresh and dry biomass of the aerial part of the plants were evaluated at 40 DAI. Concentrations of the mild strains, based on absorbance values of the PTA-ELISA, were lower than the concentration of the severe strain for all species. The mild strains did not cause mosaic in infected plants of all species. Plants of zucchini squash and watermelon infected by the severe strain exhibited severe mosaic symptoms, but the same was not noticed for infected long-neck squash plants. Biomass values from zucchini squash and watermelon plants infected by the mild strains were 1.7 % to 12.4 % lower as compared to healthy plants. Biomass values of zucchini squash and watermelon plants infected by the severe strain presented greater reduction, varying from 29 % to 74 %. However, biomass values of long-neck squash plants infected by the mild and severe strains were similar for all treatments.

  12. Can we beat the biotin-avidin pair?: cucurbit[7]uril-based ultrahigh affinity host-guest complexes and their applications.

    Science.gov (United States)

    Shetty, Dinesh; Khedkar, Jayshree K; Park, Kyeng Min; Kim, Kimoon

    2015-12-07

    The design of synthetic, monovalent host-guest molecular recognition pairs is still challenging and of particular interest to inquire into the limits of the affinity that can be achieved with designed systems. In this regard, cucurbit[7]uril (CB[7]), an important member of the host family cucurbit[n]uril (CB[n], n = 5-8, 10, 14), has attracted much attention because of its ability to form ultra-stable complexes with multiple guests. The strong hydrophobic effect between the host cavity and guests, ion-dipole and dipole-dipole interactions of guests with CB portals helps in cooperative and multiple noncovalent interactions that are essential for realizing such strong complexations. These highly selective, strong yet dynamic interactions can be exploited in many applications including affinity chromatography, biomolecule immobilization, protein isolation, biological catalysis, and sensor technologies. In this review, we summarize the progress in the development of high affinity guests for CB[7], factors affecting the stability of complexes, theoretical insights, and the utility of these high affinity pairs in different challenging applications.

  13. Seletividade de inseticidas, recomendados para cucurbitáceas para Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae em condições de laboratório

    Directory of Open Access Journals (Sweden)

    Dirceu Pratissoli

    2011-10-01

    Full Text Available As brocas-das-cucurbitáceas Diaphania spp. são as principais pragas das cucurbitáceas, podendo ocasionar perdas de até 100% na produção. A fim de reduzir o uso de inseticidas, o controle biológico, aplicado com parasitoides do gênero Trichogramma, tem-se destacado. Objetivou-se avaliar a seletividade dos ingredientes ativos abamectina, tiacloprido e clorfenapir, para Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae. Para isso, 20 fêmeas recém-emergidas de T. atopovirilla foram individualizadas, em tubos de vidro (2,5 cm de diâmetro x 8,5 cm de comprimento, e oferecidas cartelas com 30 ovos de Diaphania hyalinata (Linnaeus (Lepidoptera: Pyralidae, previamente imersas por cinco segundos em calda química. Os ingredientes ativos abamectina, tiacloprido e clorfenapir não afetaram o parasitismo de T. atopovirilia. Clorfenapir reduziu a emergência. Abamectina e tiacloprido são os mais recomendados no manejo integrado de pragas, pois foram os que se mostraram mais seletivos a T. atopovirilia em ovos de D. hyalinata.

  14. Detection of Cucurbit chlorotic yellows virus from Bemisia tabaci captured on sticky traps using reverse transcription loop-mediated isothermal amplification (RT-LAMP) and simple template preparation.

    Science.gov (United States)

    Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

    2015-09-01

    Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. (TECTONA GRANDIS LEAF POWDER

    Directory of Open Access Journals (Sweden)

    Yash Mishra

    2015-01-01

    Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

  16. Detection of viruses and the spatial and temporal spread patterns of viral diseases of cucurbits (Cucurbitaceae spp.) in the coastal savannah zone of Ghana

    International Nuclear Information System (INIS)

    Gyamena, A. E

    2013-07-01

    Cucurbits are susceptible to over 35 plant viruses; each of these viruses is capable of causing total crop failure in a poorly managed virus pathosystem. The objectives of this study were to detect the viruses that infect six cucurbit species in the coastal savannah zone of Ghana and to describe the spatial and temporal spread patterns of virus epidemics in zucchini squash (Cucurbita pepo L.) by the use of mathematical and geostatistical models. Cucumber (Cucumis sativus L.), watermelon (Citrullus lanatus Thunb.), zucchini squash (Cucurbita pepo L.), butternut squash (Cucurbita moschata Duchesne), egushi (Citrullus colocynthis L. Schrad.) and melon (Cucumis melo L.) were grown on an experimental field in the coastal savannah zone of Ghana and were monitored for the expression of virus and virus-like symptoms. The observed symptoms were further confirmed by Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS ELISA) and mechanical inoculation of indicator plants. The temporal spread patterns of virus disease in zucchini squash were analyzed by exponential logistic, monomolecular and gompertz mechanistic models. The spatial patterns of virus disease spread in zucchini squash field were analyzed by semivariograms and inverse distance weighing (IDW) methods. Cucumber, zucchini squash, melon and butternut squash were infected by both Cucumber mosaic virus (CMW) and Papaya ringspot virus (PRSV-W). Egushi was infected by CMW but not PRSV-W. None of the six cucurbit species were infected by Watermelon mosaic virus (WMV) or Zucchini yellow mosaic virus (ZYMV). The temporal pattern of disease incidence in the zucchini squash field followed the gompertz function with an average apparent infection rate of 0.026 per day. The temporal pattern of disease severity was best described by the exponential model with coefficient of determination of 94.38 % and rate of progress disease severity of 0.114 per day. As at 49 days after planting (DAP), disease incidence and

  17. Insights from the Genome Sequence of Acidovorax citrulli M6, a Group I Strain of the Causal Agent of Bacterial Fruit Blotch of Cucurbits.

    Science.gov (United States)

    Eckshtain-Levi, Noam; Shkedy, Dafna; Gershovits, Michael; Da Silva, Gustavo M; Tamir-Ariel, Dafna; Walcott, Ron; Pupko, Tal; Burdman, Saul

    2016-01-01

    Acidovorax citrulli is a seedborne bacterium that causes bacterial fruit blotch of cucurbit plants including watermelon and melon. A. citrulli strains can be divided into two major groups based on DNA fingerprint analyses and biochemical properties. Group I strains have been generally isolated from non-watermelon cucurbits, while group II strains are closely associated with watermelon. In the present study, we report the genome sequence of M6, a group I model A. citrulli strain, isolated from melon. We used comparative genome analysis to investigate differences between the genome of strain M6 and the genome of the group II model strain AAC00-1. The draft genome sequence of A. citrulli M6 harbors 139 contigs, with an overall approximate size of 4.85 Mb. The genome of M6 is ∼500 Kb shorter than that of strain AAC00-1. Comparative analysis revealed that this size difference is mainly explained by eight fragments, ranging from ∼35-120 Kb and distributed throughout the AAC00-1 genome, which are absent in the M6 genome. In agreement with this finding, while AAC00-1 was found to possess 532 open reading frames (ORFs) that are absent in strain M6, only 123 ORFs in M6 were absent in AAC00-1. Most of these M6 ORFs are hypothetical proteins and most of them were also detected in two group I strains that were recently sequenced, tw6 and pslb65. Further analyses by PCR assays and coverage analyses with other A. citrulli strains support the notion that some of these fragments or significant portions of them are discriminative between groups I and II strains of A. citrulli. Moreover, GC content, effective number of codon values and cluster of orthologs' analyses indicate that these fragments were introduced into group II strains by horizontal gene transfer events. Our study reports the genome sequence of a model group I strain of A. citrulli, one of the most important pathogens of cucurbits. It also provides the first comprehensive comparison at the genomic level between the

  18. Controlling the root and stem rot of cucumber, caused by Pythium aphanidermatum, using resistance cultivars and grafting onto the cucurbit rootstocks

    Directory of Open Access Journals (Sweden)

    Fatemeh Rostami

    2015-02-01

    Full Text Available Cucumber damping off caused by Pythium aphanidermatum is the most important root and stem rot that limits greenhouse cultivations. In this study, relative susceptibility of grafting commercial cucumber cultivars including Alpha, Caspian 340, Storm 5910, Shalim 616, Delta scar, Janette 810, Festibal C5, Royal, Negyn, Soltan and Fadia on two Cucurbita rootstocks were evaluated against P. aphanidermatum . Disease severity, survival and seedling growth were used for the evaluation. The results showed significant differences between the studied cultivars (p≤0.01. Caspian 340 and Alpha with 15.7% and 100% disease severity had more and less tolerant to P. aphanidermatum, respectively. Cucurbita maxima rootstock was more resistant than Cucurbita pepo to P. aphanidermatum. C. pepo had less compatibility with the cucumber and showed little resistance to the pathogen. The study revealed that grafting Caspian340 on the resistant cucurbit rootstock i.e. Cucurbita maxima could be used as disease control strategies in greenhouses.

  19. Apple latent spherical virus vectors for reliable and effective virus-induced gene silencing among a broad range of plants including tobacco, tomato, Arabidopsis thaliana, cucurbits, and legumes

    International Nuclear Information System (INIS)

    Igarashi, Aki; Yamagata, Kousuke; Sugai, Tomokazu; Takahashi, Yukari; Sugawara, Emiko; Tamura, Akihiro; Yaegashi, Hajime; Yamagishi, Noriko; Takahashi, Tsubasa; Isogai, Masamichi; Takahashi, Hideki; Yoshikawa, Nobuyuki

    2009-01-01

    Apple latent spherical virus (ALSV) vectors were evaluated for virus-induced gene silencing (VIGS) of endogenous genes among a broad range of plant species. ALSV vectors carrying partial sequences of a subunit of magnesium chelatase (SU) and phytoene desaturase (PDS) genes induced highly uniform knockout phenotypes typical of SU and PDS inhibition on model plants such as tobacco and Arabidopsis thaliana, and economically important crops such as tomato, legume, and cucurbit species. The silencing phenotypes persisted throughout plant growth in these plants. In addition, ALSV vectors could be successfully used to silence a meristem gene, proliferating cell nuclear antigen and disease resistant N gene in tobacco and RCY1 gene in A. thaliana. As ALSV infects most host plants symptomlessly and effectively induces stable VIGS for long periods, the ALSV vector is a valuable tool to determine the functions of interested genes among a broad range of plant species.

  20. Maize YABBY genes drooping leaf1 and drooping leaf2 affect agronomic traits by regulating leaf architecture

    Science.gov (United States)

    Leaf architectural traits, such as length, width and angle, directly influence canopy structure and light penetration, photosynthate production and overall yield. We discovered and characterized a maize (Zea mays) mutant with aberrant leaf architecture we named drooping leaf1 (drl1), as leaf blades ...

  1. A Nexus between Theory and Experiment: Non-Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]uril⋅Guest Binding Interactions.

    Science.gov (United States)

    Hostaš, Jiří; Sigwalt, David; Šekutor, Marina; Ajani, Haresh; Dubecký, Matúš; Řezáč, Jan; Zavalij, Peter Y; Cao, Liping; Wohlschlager, Christian; Mlinarić-Majerski, Kata; Isaacs, Lyle; Glaser, Robert; Hobza, Pavel

    2016-11-21

    A training set of eleven X-ray structures determined for biomimetic complexes between cucurbit[n]uril (CB[7 or 8]) hosts and adamantane-/diamantane ammonium/aminium guests were studied with DFT-D3 quantum mechanical computational methods to afford ΔG calcd binding energies. A novel feature of this work is that the fidelity of the BLYP-D3/def2-TZVPP choice of DFT functional was proven by comparison with more accurate methods. For the first time, the CB[n]⋅guest complex binding energy subcomponents [for example, ΔE dispersion , ΔE electrostatic , ΔG solvation , binding entropy (-TΔS), and induced fit E deformation(host) , E deformation(guest) ] were calculated. Only a few weeks of computation time per complex were required by using this protocol. The deformation (stiffness) and solvation properties (with emphasis on cavity desolvation) of cucurbit[n]uril (n=5, 6, 7, 8) isolated host molecules were also explored by means of the DFT-D3 method. A high ρ 2 =0.84 correlation coefficient between ΔG exptl and ΔG calcd was achieved without any scaling of the calculated terms (at 298 K). This linear dependence was utilized for ΔG calcd predictions of new complexes. The nature of binding, including the role of high energy water molecules, was also studied. The utility of introduction of tethered [-(CH 2 ) n NH 3 ] + amino loops attached to N,N-dimethyl-adamantane-1-amine and N,N,N',N'-tetramethyl diamantane-4,9-diamine skeletons (both from an experimental and a theoretical perspective) is presented here as a promising tool for the achievement of new ultra-high binding guests to CB[7] hosts. Predictions of not yet measured equilibrium constants are presented herein. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Effect of Plant Growth Regulators on Leaf Number, Leaf Area and Leaf Dry Matter in Grape

    Directory of Open Access Journals (Sweden)

    Zahoor Ahmad BHAT

    2011-03-01

    Full Text Available Influence of phenylureas (CPPU and brassinosteriod (BR along with GA (gibberellic acid were studied on seedless grape vegetative characteristics like leaf number, leaf area and leaf dry matter. Growth regulators were sprayed on the vines either once (7 days after fruit set or 15 days after fruit set or twice (7+15 days after fruit set. CPPU 2 ppm+BR 0.4 ppm+GA 25 ppm produced maximum number of leaves (18.78 while as untreated vines produced least leaf number (16.22 per shoot. Maximum leaf area (129.70 cm2 and dry matter content (26.51% was obtained with higher CPPU (3 ppm and BR (0.4 ppm combination along with GA 25 ppm. Plant growth regulators whether naturally derived or synthetic are used to improve the productivity and quality of grapes. The relatively high value of grapes justifies more expensive inputs. A relatively small improvement in yield or fruit quality can justify the field application of a very costly product. Application of new generation growth regulators like brassinosteroids and phenylureas like CPPU have been reported to increase the leaf number as well as leaf area and dry matter thereby indirectly influencing the fruit yield and quality in grapes.

  3. Why do leaf-tying caterpillars abandon their leaf ties?

    Directory of Open Access Journals (Sweden)

    Michelle Sliwinski

    2013-09-01

    Full Text Available Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats, but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently

  4. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  5. A Global Data Set of Leaf Photosynthetic Rates, Leaf N and P, and Specific Leaf Area

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This global data set of photosynthetic rates and leaf nutrient traits was compiled from a comprehensive literature review. It includes estimates of Vcmax...

  6. A Global Data Set of Leaf Photosynthetic Rates, Leaf N and P, and Specific Leaf Area

    Data.gov (United States)

    National Aeronautics and Space Administration — This global data set of photosynthetic rates and leaf nutrient traits was compiled from a comprehensive literature review. It includes estimates of Vcmax (maximum...

  7. Phylogenetic analysis of Melon chlorotic leaf curl virus from Guatemala: Another emergent species in the Squash leaf curl virus clade

    KAUST Repository

    Brown, J.K.; Mills-Lujan, K.; Idris, Ali

    2011-01-01

    divergent owing in part to recombination, but also due to the accumulation of a substantial number of mutations. In addition they are differentially host-adapted, as has been documented for other cucurbit-infecting, bean-adapted, species in the SLCV clade

  8. Biophysical control of leaf temperature

    Science.gov (United States)

    Dong, N.; Prentice, I. C.; Wright, I. J.

    2014-12-01

    In principle sunlit leaves can maintain their temperatures within a narrower range than ambient temperatures. This is an important and long-known (but now overlooked) prediction of energy balance theory. Net radiation at leaf surface in steady state (which is reached rapidly) must be equal to the combination of sensible and latent heat exchanges with surrounding air, the former being proportional to leaf-to-air temperature difference (ΔT), the latter to the transpiration rate. We present field measurements of ΔT which confirm the existence of a 'crossover temperature' in the 25-30˚C range for species in a tropical savanna and a tropical rainforest environment. This finding is consistent with a simple representation of transpiration as a function of net radiation and temperature (Priestley-Taylor relationship) assuming an entrainment factor (ω) somewhat greater than the canonical value of 0.26. The fact that leaves in tropical forests are typically cooler than surrounding air, often already by solar noon, is consistent with a recently published comparison of MODIS day-time land-surface temperatures with air temperatures. Theory further predicts a strong dependence of leaf size (which is inversely related to leaf boundary-layer conductance, and therefore to absolute magnitude of ΔT) on moisture availability. Theoretically, leaf size should be determined by either night-time constraints (risk of frost damage to active leaves) or day-time constraints (risk of heat stress damage),with the former likely to predominate - thereby restricting the occurrence of large leaves - at high latitudes. In low latitudes, daytime maximum leaf size is predicted to increase with temperature, provided that water is plentiful. If water is restricted, however, transpiration cannot proceed at the Priestley-Taylor rate, and it quickly becomes advantageous for plants to have small leaves, which do not heat up much above the temperature of their surroundings. The difference between leaf

  9. Waiting for the Leaf; Warten auf den Leaf

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, Jan

    2012-01-15

    Nissan will be the first manufacturer to launch an electric vehicle of the VW Golf category in the German market. With a mileage of about 170 km and a roomy passenger compartment, the Leaf promises much comfort. In the US market, it was launched two years ago. Was it worth while waiting for?.

  10. Effect of nitrogen supply on leaf appearance, leaf growth, leaf nitrogen economy and photosynthetic capacity in maize (Zea mays L.)

    NARCIS (Netherlands)

    Vos, J.; Putten, van der P.E.L.; Birch, C.J.

    2005-01-01

    Leaf area growth and nitrogen concentration per unit leaf area, Na (g m-2 N) are two options plants can use to adapt to nitrogen limitation. Previous work indicated that potato (Solanum tuberosum L.) adapts the size of leaves to maintain Na and photosynthetic capacity per unit leaf area. This paper

  11. Spectral reflectance relationships to leaf water stress

    Science.gov (United States)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  12. An evolutionary perspective on leaf economics : Phylogenetics of leaf mass per area in vascular plants

    NARCIS (Netherlands)

    Flores, Olivier; Garnier, Eric; Wright, Ian J.; Reich, Peter B.; Pierce, Simon; Diaz, Sandra; Pakeman, Robin J.; Rusch, Graciela M.; Bernard-Verdier, Maud; Testi, Baptiste; Bakker, Jan P.; Bekker, Renee M.; Cerabolini, Bruno E. L.; Ceriani, Roberta M.; Cornu, Guillaume; Cruz, Pablo; Delcamp, Matthieu; Dolezal, Jiri; Eriksson, Ove; Fayolle, Adeline; Freitas, Helena; Golodets, Carly; Gourlet-Fleury, Sylvie; Hodgson, John G.; Brusa, Guido; Kleyer, Michael; Kunzmann, Dieter; Lavorel, Sandra; Papanastasis, Vasilios P.; Perez-Harguindeguy, Natalia; Vendramini, Fernanda; Weiher, Evan

    In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This "worldwide leaf economics spectrum" consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf

  13. The Nissan LEAF electric powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Nakazawa, Shinsuke [Nissan Motor Co., Ltd. (Japan)

    2011-07-01

    The need for CO{sub 2} reduction as a countermeasure to global warming, and to move away from our dependence on fossil fuels as a countermeasure to energy security are urgent issues. One of the ultimate goals to achieving these targets is to develop a 'Zero emission car' such as an electric vehicle or a fuel cell vehicle, along with the manufacturing of clean energy. Nissan have developed a new powertrain for the electric vehicle, and have installed it in the Nissan LEAF. Sales of the Nissan LEAF started in North America, Europe and Japan in 2010, with plans to sell it globally by 2012. In order to achieve an improved driving range, power performance and drivability performance, Nissan have adapted a high efficiency synchronous motor, a water-cooled inverter, and reducer. Moreover, the Nissan LEAF has the capability of a 3.3kW AC charge and a 50kW DC quick charge. This presentation will introduce the features of the electric powertrain adopted for Nissan LEAF. (orig.)

  14. 7 CFR 30.2 - Leaf tobacco.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2 Leaf...

  15. 7 CFR 29.3035 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements...

  16. 7 CFR 29.6023 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its...

  17. 7 CFR 29.1030 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See...

  18. 7 CFR 29.3527 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See...

  19. 7 CFR 29.3526 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling...

  20. 7 CFR 29.3034 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and...

  1. 7 CFR 29.6022 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results...

  2. Betel leaf in stoma care.

    Science.gov (United States)

    Banu, Tahmina; Talukder, Rupom; Chowdhury, Tanvir Kabir; Hoque, Mozammel

    2007-07-01

    Construction of a stoma is a common procedure in pediatric surgical practice. For care of these stomas, commercially available devices such as ostomy bag, either disposable or of longer duration are usually used. These are expensive, particularly in countries like Bangladesh, and proper-sized ones are not always available. We have found an alternative for stoma care, betel leaf, which is suitable for Bangladeshis. We report the outcome of its use. After construction of stoma, at first zinc oxide paste was applied on the peristomal skin. A betel leaf with shiny, smooth surface outwards and rough surface inwards was put over the stoma with a hole made in the center according to the size of stoma. Another intact leaf covers the stomal opening. When bowel movement occurs, the overlying intact leaf was removed and the fecal matter was washed away from both. The leaves were reused after cleaning. Leaves were changed every 2 to 3 days. From June 1998 to December 2005, in the department of pediatric surgery, Chittagong Medical College and Hospital, Chittagong, Bangladesh, a total of 623 patients had exteriorization of bowel. Of this total, 495 stomas were cared for with betel leaves and 128 with ostomy bags. Of 623 children, 287 had sigmoid colostomy, 211 had transverse colostomy, 105 had ileostomy, and 20 had jejunostomy. Of the 495 children under betel leaf stoma care, 13 patients (2.6%) developed skin excoriation. There were no allergic reactions. Of the 128 patients using ostomy bag, 52 (40.65%) had skin excoriation. Twenty-four (18.75%) children developed some allergic reactions to adhesive. Monthly costs for betel leaves were 15 cents (10 BDT), whereas ostomy bags cost about US$24. In the care of stoma, betel leaves are cheap, easy to handle, nonirritant, and nonallergic.

  3. Interactions between photoacidic 3-hydroxynaphtho[1,2-b]quinolizinium and cucurbit[7]uril: Influence on acidity in the ground and excited state

    Directory of Open Access Journals (Sweden)

    Jonas Becher

    2017-02-01

    Full Text Available 3-Hydroxynaphtho[1,2-b]quinolizinium was synthesized by cyclodehydration route and its optical properties in different media were investigated. The absorption and emission spectra of this compound depend on the pH of the solution. Thus, at higher pH values the deprotonation yields a merocyanine-type dye that exhibits significantly red-shifted absorption bands and causes a dual emisson, i.e., a combination of emission bands of the hydroxyquinolizinium and its deprotonated form. Whereas this compound is a weak acid in the ground state (pKa = 7.9, it has a strongly increased acidity in the excited state (pKa* = 0.4. As a result, the blue-shifted fluorescence of the hydroxyquinolizinium becomes dominant only under strongly acidic conditions. In addition, it is shown that 3-hydroxynaphtho[1,2-b]quinolizinium binds to cucurbit[7]uril (CB[7] with moderate affinity (Kb = 1.8 × 104 M−1, pH 5 and that the pKa and pKa* values of this ligand increase by about two to three orders of magnitude, respectively, when bound to CB[7].

  4. Theoretical investigation of inclusion complex formation of Gold (III – Dimethyldithiocarbamate anticancer agents with cucurbit[n = 5,6]urils

    Directory of Open Access Journals (Sweden)

    Zabiollah Mahdavifar

    2014-09-01

    Full Text Available Gold (III-N,N-dimethyldithiocarbamate [DMDT(AuX2] complexes have recently gained increasing attention as potential anticancer agents because of their strong tumor cell growth–inhibitory effects, generally achieved by exploiting non-cisplatin-like mechanisms of action. The goal of our research work is to encapsulate the gold(III dimethyldithiocarbamate complexes as anticancer with cucurbit[n]urils (CB[n = 5, 6] by accurate calculations, to predict the inclusion complex formation of gold(III species with cucurbiturils (CB[n = 5, 6]. The calculations were carried out just for the 1:1 stoichiometric complexes. Upon encapsulation, binding energy, thermodynamic parameters, structural parameters and electronic structures of complexes are investigated. The results of the thermodynamic calculations and the binding energy show that the inclusion process is exothermic and the CB[6]/[DMDT(AuBr2] complex is more stable than other complexes. The final geometry of CB[n]/drugs indicates that the drugs were expelled from the cavity of CB[n]. NBO calculations reveal that the hydrogen bonding between CB[n] and drugs and electrostatic interactions are the major factors contributing to the overall stabilities of the complexes.

  5. Excited-state proton transfer in confined medium. 4-methyl-7-hydroxyflavylium and β-naphthol incorporated in cucurbit[7]uril.

    Science.gov (United States)

    Basílio, Nuno; Laia, César A T; Pina, Fernando

    2015-02-12

    Excited-state proton transfer (ESPT) was studied by fluorescent emission using a mathematical model recast from the Weller theory. The titration curves can be fitted with three parameters: pK(a) (acidity constant of the ground sate), pK(ap)* (apparent acidity constant of the excited state), and η(A*), the efficiency of excited base formation from the excited acid. β-Naphthol and 4-metyhl-7-hydroxyflavylium were studied in aqueous solution and upon incorporation in cucurbit[7]uril. For all the compounds studied the interaction with the host leads to 1:1 adducts and the ground-state pK(a) increases upon incorporation. Whereas the ESPT of 4-methyl-7-hydroxyflavylium practically does not change in the presence of the host, in the case of β-naphthol it is prevented and the fluorescence emission titration curves are coincident with those taken by absorption. The position of the guest inside the host was investigated by NMR experiments and seems to determine the efficiency of the ESPT. The ESPT decreases for the guest, exhibiting a great protection of the phenol to the bulk water interaction.

  6. Cell Adhesion on RGD-Displaying Knottins with Varying Numbers of Tryptophan Amino Acids to Tune the Affinity for Assembly on Cucurbit[8]uril Surfaces.

    Science.gov (United States)

    Sankaran, Shrikrishnan; Cavatorta, Emanuela; Huskens, Jurriaan; Jonkheijm, Pascal

    2017-09-05

    Cell adhesion is studied on multivalent knottins, displaying RGD ligands with a high affinity for integrin receptors, that are assembled on CB[8]-methylviologen-modified surfaces. The multivalency in the knottins stems from the number of tryptophan amino acid moieties, between 0 and 4, that can form a heteroternary complex with cucurbit[8]uril (CB[8]) and surface-tethered methylviologen (MV 2+ ). The binding affinity of the knottins with CB[8] and MV 2+ surfaces was evaluated using surface plasmon resonance spectroscopy. Specific binding occurred, and the affinity increased with the valency of tryptophans on the knottin. Additionally, increased multilayer formation was observed, attributed to homoternary complex formation between tryptophan residues of different knottins and CB[8]. Thus, we were able to control the surface coverage of the knottins by valency and concentration. Cell experiments with mouse myoblast (C2C12) cells on the self-assembled knottin surfaces showed specific integrin recognition by the RGD-displaying knottins. Moreover, cells were observed to elongate more on the supramolecular knottin surfaces with a higher valency, and in addition, more pronounced focal adhesion formation was observed on the higher-valency knottin surfaces. We attribute this effect to the enhanced coverage and the enhanced affinity of the knottins in their interaction with the CB[8] surface. Collectively, these results are promising for the development of biomaterials including knottins via CB[8] ternary complexes for tunable interactions with cells.

  7. Both structural and non-structural forms of the readthrough protein of cucurbit aphid-borne yellows virus are essential for efficient systemic infection of plants.

    Directory of Open Access Journals (Sweden)

    Sylvaine Boissinot

    Full Text Available Cucurbit aphid-borne yellows virus (CABYV is a polerovirus (Luteoviridae family with a capsid composed of the major coat protein and a minor component referred to as the readthrough protein (RT. Two forms of the RT were reported: a full-length protein of 74 kDa detected in infected plants and a truncated form of 55 kDa (RT* incorporated into virions. Both forms were detected in CABYV-infected plants. To clarify the specific roles of each protein in the viral cycle, we generated by deletion a polerovirus mutant able to synthesize only the RT* which is incorporated into the particle. This mutant was unable to move systemically from inoculated leaves inferring that the C-terminal half of the RT is required for efficient long-distance transport of CABYV. Among a collection of CABYV mutants bearing point mutations in the central domain of the RT, we obtained a mutant impaired in the correct processing of the RT which does not produce the RT*. This mutant accumulated very poorly in upper non-inoculated leaves, suggesting that the RT* has a functional role in long-distance movement of CABYV. Taken together, these results infer that both RT proteins are required for an efficient CABYV movement.

  8. Both structural and non-structural forms of the readthrough protein of cucurbit aphid-borne yellows virus are essential for efficient systemic infection of plants.

    Science.gov (United States)

    Boissinot, Sylvaine; Erdinger, Monique; Monsion, Baptiste; Ziegler-Graff, Véronique; Brault, Véronique

    2014-01-01

    Cucurbit aphid-borne yellows virus (CABYV) is a polerovirus (Luteoviridae family) with a capsid composed of the major coat protein and a minor component referred to as the readthrough protein (RT). Two forms of the RT were reported: a full-length protein of 74 kDa detected in infected plants and a truncated form of 55 kDa (RT*) incorporated into virions. Both forms were detected in CABYV-infected plants. To clarify the specific roles of each protein in the viral cycle, we generated by deletion a polerovirus mutant able to synthesize only the RT* which is incorporated into the particle. This mutant was unable to move systemically from inoculated leaves inferring that the C-terminal half of the RT is required for efficient long-distance transport of CABYV. Among a collection of CABYV mutants bearing point mutations in the central domain of the RT, we obtained a mutant impaired in the correct processing of the RT which does not produce the RT*. This mutant accumulated very poorly in upper non-inoculated leaves, suggesting that the RT* has a functional role in long-distance movement of CABYV. Taken together, these results infer that both RT proteins are required for an efficient CABYV movement.

  9. pH Responsive Self-Assembly of Cucurbit[7]urils and Polystyrene-Block-Polyvinylpyridine Micelles for Hydrophobic Drug Delivery

    Directory of Open Access Journals (Sweden)

    Basem A. Moosa

    2013-01-01

    Full Text Available Polystyrene-block-polyvinylpyridine (PS-b-P4VP polypseudorotaxanes with cucurbit[7]urils (CB[7] were prepared from water soluble PS-b-P4VPH+ polymer and CB[7] in aqueous solution at room temperature. At acidic and neutral pH, the pyridinium block of PS-b-P4VP is protonated (PS-b-P4VPH+ pushing CB[7] to preferably host the P4VP block. At basic pH (pH 8, P4VP is not charged and thus is not able to strongly complex CB[7]. This phenomenon was verified further by monitoring the release of pyrene, a hydrophobic cargo model, from a PS-b-P4VPH+/CB[7] micellar membrane. Release study of UV active pyrene from the membrane at different pH values revealed that the system is only operational under basic conditions and that the host-guest interaction of CB[7] with P4VPH+ significantly slows down cargo release.

  10. Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups.

    Science.gov (United States)

    Reich, Peter B; Walters, Michael B; Ellsworth, David S; Vose, James M; Volin, John C; Gresham, Charles; Bowman, William D

    1998-05-01

    Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (R d ) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (A max ). However, it is not known whether such scaling, if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between R d measured at a standard temperature and leaf life-span, N, SLA and A max for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed conifers) in six biomes traversing the Americas: alpine tundra/subalpine forest, Colorado; cold temperate forest/grassland, Wisconsin; cool temperate forest, North Carolina; desert/shrubland, New Mexico; subtropical forest, South Carolina; and tropical rain forest, Amazonas, Venezuela. Area-based R d was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based R d (R d-mass ) decreased sharply with increasing leaf life-span and was positively related to SLA and mass-based A max and leaf N (leaf N mass ). These intra-biome relationships were similar in shape and slope among sites, where in each case we compared species belonging to different plant functional groups. Significant R d-mass -N mass relationships were observed in all functional groups (pooled across sites), but the relationships differed, with higher R d at any given leaf N in functional groups (such as forbs) with higher SLA and shorter leaf life-span. Regardless of biome or functional group, R d-mass was well predicted by all combinations of leaf life-span, N mass and/or SLA (r 2 ≥ 0.79, P morphological, chemical and metabolic traits.

  11. The Diaporthe sojae species complex: Phylogenetic re-assessment of pathogens associated with soybean, cucurbits and other field crops.

    Science.gov (United States)

    Udayanga, Dhanushka; Castlebury, Lisa A; Rossman, Amy Y; Chukeatirote, Ekachai; Hyde, Kevin D

    2015-05-01

    Phytopathogenic species of Diaporthe are associated with a number of soybean diseases including seed decay, pod and stem blight and stem canker and lead to considerable crop production losses worldwide. Accurate morphological identification of the species that cause these diseases has been difficult. In this study, we determined the phylogenetic relationships and species boundaries of Diaporthe longicolla, Diaporthe phaseolorum, Diaporthe sojae and closely related taxa. Species boundaries for this complex were determined based on combined phylogenetic analysis of five gene regions: partial sequences of calmodulin (CAL), beta-tubulin (TUB), histone-3 (HIS), translation elongation factor 1-α (EF1-α), and the nuclear ribosomal internal transcribed spacers (ITS). Phylogenetic analyses revealed that this large complex of taxa is comprised of soybean pathogens as well as species associated with herbaceous field crops and weeds. Diaporthe arctii, Diaporthe batatas, D. phaseolorum and D. sojae are epitypified. The seed decay pathogen D. longicolla was determined to be distinct from D. sojae. D. phaseolorum, originally associated with stem and leaf blight of Lima bean, was not found to be associated with soybean. A new species, Diaporthe ueckerae on Cucumis melo, is introduced with description and illustrations. Published by Elsevier Ltd.

  12. Analysis of Peanut Leaf Proteome

    DEFF Research Database (Denmark)

    Ramesh, R.; Suravajhala, Prashanth; Pechan, T.

    2010-01-01

    Peanut (Arachis hypogaea) is one of the most important sources of plant protein. Current selection of genotypes requires molecular characterization of available populations. Peanut genome database has several EST cDNAs which can be used to analyze gene expression. Analysis of proteins is a direct...... approach to define function of their associated genes. Proteome analysis linked to genome sequence information is critical for functional genomics. However, the available protein expression data is extremely inadequate. Proteome analysis of peanut leaf was conducted using two-dimensional gel...... electrophoresis in combination with sequence identification using MALDI/TOF to determine their identity and function related to growth, development and responses to stresses. Peanut leaf proteins were resolved into 300 polypeptides with pI values between 3.5 and 8.0 and relative molecular masses from 12 to 100 k...

  13. Can Leaf Spectroscopy Predict Leaf and Forest Traits Along a Peruvian Tropical Forest Elevation Gradient?

    Science.gov (United States)

    Doughty, Christopher E.; Santos-Andrade, P. E.; Goldsmith, G. R.; Blonder, B.; Shenkin, A.; Bentley, L. P.; Chavana-Bryant, C.; Huaraca-Huasco, W.; Díaz, S.; Salinas, N.; Enquist, B. J.; Martin, R.; Asner, G. P.; Malhi, Y.

    2017-11-01

    High-resolution spectroscopy can be used to measure leaf chemical and structural traits. Such leaf traits are often highly correlated to other traits, such as photosynthesis, through the leaf economics spectrum. We measured VNIR (visible-near infrared) leaf reflectance (400-1,075 nm) of sunlit and shaded leaves in 150 dominant species across ten, 1 ha plots along a 3,300 m elevation gradient in Peru (on 4,284 individual leaves). We used partial least squares (PLS) regression to compare leaf reflectance to chemical traits, such as nitrogen and phosphorus, structural traits, including leaf mass per area (LMA), branch wood density and leaf venation, and "higher-level" traits such as leaf photosynthetic capacity, leaf water repellency, and woody growth rates. Empirical models using leaf reflectance predicted leaf N and LMA (r2 > 30% and %RMSE < 30%), weakly predicted leaf venation, photosynthesis, and branch density (r2 between 10 and 35% and %RMSE between 10% and 65%), and did not predict leaf water repellency or woody growth rates (r2<5%). Prediction of higher-level traits such as photosynthesis and branch density is likely due to these traits correlations with LMA, a trait readily predicted with leaf spectroscopy.

  14. Caractérisation botanique et agronomique de trois espèces de cucurbites consommées en sauce en Afrique de l'Ouest : Citrullus sp., Cucumeropsis mannii Naudin et Lagenaria siceraria (Molina Standl

    Directory of Open Access Journals (Sweden)

    Zoro Bi I.A.

    2003-01-01

    Full Text Available Botanical and agronomical characterisation of three species of cucurbit consumed as sauce in West Africa: Citrullus sp., Cucumeropsis mannii Naudin and Lagenaria siceraria (Molina Standl. There are in Côte d'Ivoire at least five species of cucurbit incorrectly called ""pistaches"" in town and cultivated at small scale by women for their oleaginous seeds that are a great importance in the sociocultural live of several peoples. Nevertheless, few studies aimed at the improvement of these plants (related notably to taxonomy, genetic resources collecting missions, genetic characterisation, agronomic evaluation, and selection have been carried out. In order to set up a list of reliable traits that should be examined easily during and after collecting missions, we carry out in the present study, for three species (Citrullus sp., Cucumeropsis mannii Naudin and Lagenaria siceraria (Molina Standl a botanic description and an analysis of eleven agronomic traits: 100-seeds weight, germination rate, seedlings emergence time, matured fruit weight, matured fruit decomposition time, mean number of seeds per fruit, seeds shape, fruit diameter, fruit interior cavity diameter, flowering time, and fruiting time. Statistical analyses using nine of these traits showed that the three species can be completely distinguished with six traits whereas the three other traits allowed partial distinction. Low yields have been observed for the three species: 11.41 kg/ha of decorticated seeds for C. mannii, 18.51 kg/ha for Citrullus sp. and 75.14 kg/ha for L. siceraria. From the observed yield components, the possibilities to improve the production of these cucurbits are discussed.

  15. Investigation of the effect of cucurbit[7]uril complexation on the photophysical and acid-base properties of the antimalarial drug quinine.

    Science.gov (United States)

    Mallick, Suman; Pal, Kaushik; Chandra, Falguni; Koner, Apurba L

    2016-11-09

    Host-guest complexation of mono and dicationic quinine with cucurbit[7]uril (CB7), a water-soluble macrocyclic host molecule, has been investigated. Job's plot, time-resolved anisotropy as well as concentration dependent NMR titration confirm the binding of two CB7 macrocycles with one quinine molecule. The binding affinity of dicationic quinine with CB7 is one order of magnitude higher than the binding constant of mono-cationic quinine. Such preferential binding results in one unit pK a shift in the ground-state of the quinoline ring. However, using fluorescence spectroscopy we have obtained two acid-dissociation constants, one for quinoline ring nitrogen and the other for the nitrogen of the quinuclidine moiety. In the excited state, CB7 complexation causes one unit pK a shift for the quinoline ring and 1.9 unit shift for the quinuclidine moiety. Interestingly, a large enhancement of fluorescence lifetime and anisotropy of quinine at pH 2.7 and pH 9.0 upon CB7 complexation was observed due to the restriction of conformational flexibility. Moreover, at pH 3.0, a large fluorescence enhancement of quinine due to CB7 complexation was observed and it was quite significant as compared to that of quinine in 0.1 (M) HCl without CB7. We believe that this study of quinine complexation with CB7 will reduce phototoxicity, increase bioavailability and offer an alternative standard for quantum yield measurements in an amiable condition.

  16. Acyclic Cucurbit[n]uril-Type Molecular Container Enables Systemic Delivery of Effective Doses of Albendazole for Treatment of SK-OV-3 Xenograft Tumors.

    Science.gov (United States)

    Hettiarachchi, Gaya; Samanta, Soumen K; Falcinelli, Shane; Zhang, Ben; Moncelet, Damien; Isaacs, Lyle; Briken, Volker

    2016-03-07

    Approximately, 40-70% of active pharmaceutical ingredients (API) are severely limited by their extremely poor aqueous solubility, and consequently, there is a high demand for excipients that can be used to formulate clinically relevant doses of these drug candidates. Here, proof-of-concept studies demonstrate the potential of our recently discovered acyclic cucurbit[n]uril-type molecular container Motor1 (M1) as a solubilizing agent for insoluble drugs. M1 did not induce significant rates of mutations in various Salmonella typhimurium test strains during the Ames test, suggesting low genotoxicity. M1 also has low risk of causing cardiac toxicity in humans since it did not inhibit the human Ether-à-go-go-Related Gene channel as tested on transfected CHO cell lines via patch clamp analysis. Albendazole (ABZ) is a widely used antihelminthic agent but that has also shown promising efficacy against cancerous cells in vitro. However, due to its low aqueous solubility (2.7 μM) and poor pharmacokinetics, ABZ is clinically limited as an anticancer agent. Here we investigated the potential of M1 as a solubilizing excipient for ABZ formulation. A pharmacokinetic study indicated that ABZ escapes the peritoneal cavity resulting in 78% absolute bioavailability, while its active intermediate metabolite, albendazole sulfoxide, achieved 43% absolute bioavailability. The daily dosing of 681 mg/kg M1 complexed with 3.2 mg/kg of ABZ for 14 days did not result in significant weight loss or pathology in Swiss Webster mice. In vivo efficacy studies using this M1·ABZ inclusion complex showed significant decreases in tumor growth rates and increases in survival of mice bearing SK-OV-3 xenograft tumors. In conclusion, we provide substantial new evidence demonstrating that M1 is a safe and efficient excipient that enables in vivo parenteral delivery of poorly water-soluble APIs.

  17. Leveraging multiple datasets for deep leaf counting

    OpenAIRE

    Dobrescu, Andrei; Giuffrida, Mario Valerio; Tsaftaris, Sotirios A

    2017-01-01

    The number of leaves a plant has is one of the key traits (phenotypes) describing its development and growth. Here, we propose an automated, deep learning based approach for counting leaves in model rosette plants. While state-of-the-art results on leaf counting with deep learning methods have recently been reported, they obtain the count as a result of leaf segmentation and thus require per-leaf (instance) segmentation to train the models (a rather strong annotation). Instead, our method tre...

  18. Leaf sequencing algorithms for segmented multileaf collimation

    International Nuclear Information System (INIS)

    Kamath, Srijit; Sahni, Sartaj; Li, Jonathan; Palta, Jatinder; Ranka, Sanjay

    2003-01-01

    The delivery of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation delivery. It is imperative that the fluence map delivered using the leaf sequence file is as close as possible to the fluence map generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. Optimization of the leaf sequencing algorithm has been the subject of several recent investigations. In this work, we present a systematic study of the optimization of leaf sequencing algorithms for segmental multileaf collimator beam delivery and provide rigorous mathematical proofs of optimized leaf sequence settings in terms of monitor unit (MU) efficiency under most common leaf movement constraints that include minimum leaf separation constraint and leaf interdigitation constraint. Our analytical analysis shows that leaf sequencing based on unidirectional movement of the MLC leaves is as MU efficient as bidirectional movement of the MLC leaves

  19. Leaf sequencing algorithms for segmented multileaf collimation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Srijit [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Sahni, Sartaj [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Li, Jonathan [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Palta, Jatinder [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ranka, Sanjay [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States)

    2003-02-07

    The delivery of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation delivery. It is imperative that the fluence map delivered using the leaf sequence file is as close as possible to the fluence map generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. Optimization of the leaf sequencing algorithm has been the subject of several recent investigations. In this work, we present a systematic study of the optimization of leaf sequencing algorithms for segmental multileaf collimator beam delivery and provide rigorous mathematical proofs of optimized leaf sequence settings in terms of monitor unit (MU) efficiency under most common leaf movement constraints that include minimum leaf separation constraint and leaf interdigitation constraint. Our analytical analysis shows that leaf sequencing based on unidirectional movement of the MLC leaves is as MU efficient as bidirectional movement of the MLC leaves.

  20. Effect of Addition of Moringa Leaf By-Product (Leaf-Waste) on ...

    African Journals Online (AJOL)

    The effects of incorporation of Moringa leaf fibre (a by-product of leaf processing which contains 24% Crude Fibre by dry weight at 0, 5 and 10 % substitution of wheat flour in cookies was investigated. Three products containing wheat flour: Moringa leaf fibre ratios of 100:0, 95:5, and 90:10 respectively were prepared, and a ...

  1. Specific leaf area estimation from leaf and canopy reflectance through optimization and validation of vegetation indices

    NARCIS (Netherlands)

    Ali, A.M.; Darvishzadeh, R.; Skidmore, A.K.; van Duren, I.C.

    2017-01-01

    Specific leaf area (SLA), which is defined as the leaf area per unit of dry leaf mass is an important component when assessing functional diversity and plays a key role in ecosystem modeling, linking plant carbon and water cycles as well as quantifying plant physiological processes. However, studies

  2. Leaf size and leaf display of thirty-eight tropical tree species

    NARCIS (Netherlands)

    Poorter, L.; Rozendaal, D.M.A.

    2008-01-01

    Trees forage for light through optimal leaf display. Effective leaf display is determined by metamer traits (i.e., the internode, petiole, and corresponding leaf), and thus these traits strongly co-determine carbon gain and as a result competitive advantage in a light-limited environment. We

  3. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  4. "Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

    Science.gov (United States)

    Burkhardt, Juergen; Hunsche, Mauricio

    2013-01-01

    "Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  5. ‘Breath figures’ on leaf surfaces – formation and effects of microscopic leaf wetness

    Directory of Open Access Journals (Sweden)

    Jürgen eBurkhardt

    2013-10-01

    Full Text Available ‘Microscopic leaf wetness’ means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 µm, microscopic leaf wetness it is about 2 orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the amount and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g. ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  6. Leaf Wetness within a Lily Canopy

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Klok, E.J.

    2005-01-01

    A wetness duration experiment was carried out within a lily field situated adjacent to coastal dunes in the Netherlands. A within-canopy model was applied to simulate leaf wetness in three layers, with equal leaf area indices, within the canopy. This simulation model is an extension of an existing

  7. 7 CFR 29.3528 - Leaf surface.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco leaf...

  8. Estimation of leaf area in tropical maize

    NARCIS (Netherlands)

    Elings, A.

    2000-01-01

    Leaf area development of six tropical maize cultivars grown in 1995 and 1996 in several tropical environments in Mexico (both favourable and moisture-and N-limited) was observed and analysed. First, the validity of a bell-shaped curve describing the area of individual leaves as a function of leaf

  9. Chromosome-damaging effect of betel leaf.

    Science.gov (United States)

    Sadasivan, G; Rani, G; Kumari, C K

    1978-05-01

    The chewing of betel leaf with other ingredients is a widespread addiction in India. The chromosome damaging effect was studied in human leukocyte cultures. There was an increase in the frequency of chromatid aberrations when the leaf extract was added to cultures.

  10. ANXIOLYTIC ACTIVITY OF OCIMUM SANCTUM LEAF EXTRACT

    OpenAIRE

    Chattopadhyay, R.R.

    1994-01-01

    The anxiolytic activity of Ocimum sanctum leaf extract was studied in mice. O.sanctum leaf extract produced significant anxiolytic activity in plus – maze and open field behaviour test models. The effect was compared with diazepam, a standard antianxiety drug.

  11. 7 CFR 29.2530 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of...

  12. 7 CFR 29.2278 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ...

  13. 7 CFR 29.2277 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2277 Section 29.2277 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists...

  14. 7 CFR 29.2529 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

  15. Easy Leaf Area: Automated digital image analysis for rapid and accurate measurement of leaf area.

    Science.gov (United States)

    Easlon, Hsien Ming; Bloom, Arnold J

    2014-07-01

    Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. • Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. • Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

  16. Easy Leaf Area: Automated Digital Image Analysis for Rapid and Accurate Measurement of Leaf Area

    Directory of Open Access Journals (Sweden)

    Hsien Ming Easlon

    2014-07-01

    Full Text Available Premise of the study: Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. Methods and Results: Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. Conclusions: Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

  17. Possible Roles of Strigolactones during Leaf Senescence

    Directory of Open Access Journals (Sweden)

    Yusuke Yamada

    2015-09-01

    Full Text Available Leaf senescence is a complicated developmental process that involves degenerative changes and nutrient recycling. The progress of leaf senescence is controlled by various environmental cues and plant hormones, including ethylene, jasmonic acid, salicylic acid, abscisic acid, cytokinins, and strigolactones. The production of strigolactones is induced in response to nitrogen and phosphorous deficiency. Strigolactones also accelerate leaf senescence and regulate shoot branching and root architecture. Leaf senescence is actively promoted in a nutrient-poor soil environment, and nutrients are transported from old leaves to young tissues and seeds. Strigolactones might act as important signals in response to nutrient levels in the rhizosphere. In this review, we discuss the possible roles of strigolactones during leaf senescence.

  18. Relating Stomatal Conductance to Leaf Functional Traits.

    Science.gov (United States)

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-10-12

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreasing leaf dry matter content (LDMC) and carbon nitrogen ratio (CN). The LES describes different strategies ranging from that of short-lived leaves with high photosynthetic capacity per leaf mass to long-lived leaves with low mass-based carbon assimilation rates. However, traits that are not included in the LES might provide additional information on the species' physiology, such as those related to stomatal control. Protocols are presented for a wide range of leaf functional traits, including traits of the LES, but also traits that are independent of the LES. In particular, a new method is introduced that relates the plants' regulatory behavior in stomatal conductance to vapor pressure deficit. The resulting parameters of stomatal regulation can then be compared to the LES and other plant functional traits. The results show that functional leaf traits of the LES were also valid predictors for the parameters of stomatal regulation. For example, leaf carbon concentration was positively related to the vapor pressure deficit (vpd) at the point of inflection and the maximum of the conductance-vpd curve. However, traits that are not included in the LES added information in explaining parameters of stomatal control: the vpd at the point of inflection of the conductance-vpd curve was lower for species with higher stomatal density and higher stomatal index. Overall, stomata and vein traits were more powerful predictors for explaining stomatal regulation than traits used in the LES.

  19. Minimising losses caused by Zucchini yellow mosaic virus in vegetable cucurbit crops in tropical, sub-tropical and Mediterranean environments through cultural methods and host resistance.

    Science.gov (United States)

    Coutts, B A; Kehoe, M A; Jones, R A C

    2011-08-01

    to the existing Integrated Disease Management strategy for ZYMV in vegetable cucurbits in WA, but necessitated modification of its recommendations over deployment of cultivars with resistance genes. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Uranyl complexes as scaffolding or spacers for cucurbit[6]uril molecules in homo- and heterometallic species, including a uranyl-lanthanide complex

    Energy Technology Data Exchange (ETDEWEB)

    Thuery, Pierre [NIMBE, CEA, CNRS, Universite Paris-Saclay, CEA Saclay, Gif-sur-Yvette (France)

    2017-06-16

    The reaction of uranyl nitrate with cucurbit[6]uril (CB6) and carboxylic or sulfonic ligands under hydrothermal conditions and in the presence of additional metal cations (K{sup I} or Ce{sup III}) or cosolvents provided four complexes, which were crystallographically characterized. The compound [(UO{sub 2}){sub 2}K{sub 2}(CB6)(adc){sub 2}(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}].5H{sub 2}O (1), where H{sub 2}adc is 1,3-adamantanedicarboxylic acid, crystallizes in the form of a central K{sub 2}(CB6){sup 2+} column surrounded by two one-dimensional (1D) polymeric UO{sub 2}(adc)(NO{sub 3}){sup -} chains attached to the column by nitrate bridges, with a perfect match of the repeat lengths in the two subunits. The longer 1,3-adamantanediacetic acid (H{sub 2}adac) gives the complex [(UO{sub 2}){sub 2}(adac){sub 2}(HCOOH){sub 2}].CB6.6H{sub 2}O (2), in which the 1D uranyl-containing polymer and columns of CB6 molecules form a layered arrangement held by weak CH..O hydrogen bonds. The complex formed with the dipotassium salt of methanedisulfonic acid (K{sub 2}mds), [(UO{sub 2}){sub 2}K{sub 2}(CB6)(mds){sub 2}(OH){sub 2}(H{sub 2}O){sub 8}].4H{sub 2}O (3), is a 1D polymer, in which K{sub 2}(CB6){sup 2+} units are connected to one another by doubly hydroxide-bridged uranyl dimers in which the disulfonates are terminal, chelating ligands; connection between the two subunits is solely through potassium oxo-bonding to uranyl. The complex [(UO{sub 2}){sub 2}Ce{sub 2}(CB6)(C{sub 2}O{sub 4}){sub 3}(NO{sub 3}){sub 4}(H{sub 2}O){sub 6}].2H{sub 2}O (4) is a 1D polymer containing bridging oxalate ligands formed in situ, in which CB6 is coordinated to the lanthanide cations only; one nitrate ligand and one water ligand, hydrogen-bonded to each other, are included in the CB6 cavity, with the possible occurrence of interactions between nitrate oxygen atoms and ureido carbon atoms. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Is the lotus leaf superhydrophobic?

    Science.gov (United States)

    Cheng, Yang-Tse; Rodak, Daniel E.

    2005-04-01

    Superhydrophobic surfaces have important technical applications ranging from self-cleaning window glasses, paints, and fabrics to low-friction surfaces. The archetype superhydrophobic surface is that of the lotus leaf. When rain falls on lotus leaves, water beads up with a contact angle in the superhydrophobic range of about 160°. The water drops promptly roll off the leaves collecting dirt along the way. This lotus effect has, in recent years, stimulated much research effort worldwide in the fabrication of surfaces with superhydrophobicity. But, is the lotus surface truly superhydrophobic? This work shows that the lotus leaves can be either hydrophobic or hydrophilic, depending on how the water gets on to their surfaces. This finding has significant ramifications on how to make and use superhydrophobic surfaces.

  2. Are leaf physiological traits related to leaf water isotopic enrichment in restinga woody species?

    Directory of Open Access Journals (Sweden)

    BRUNO H.P. ROSADO

    2013-09-01

    Full Text Available During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different enrichments between cells, and different pools of water within leaves, due to morpho-physiological traits, might lead to inaccuracies in isotopic models predicting leaf water enrichment. We evaluate the role of leaf morpho-physiological traits on leaf water isotopic enrichment in woody species occurring in a coastal vegetation of Brazil known as restinga. Hydrogen and oxygen stable isotope values of soil, plant stem and leaf water and leaf traits were measured in six species from restinga vegetation during a drought and a wet period. Leaf water isotopic enrichment relative to stem water was more homogeneous among species during the drought in contrast to the wet period suggesting convergent responses to deal to temporal heterogeneity in water availability. Average leaf water isotopic enrichment relative to stem water during the drought period was highly correlated with relative apoplastic water content. We discuss this observation in the context of current models of leaf water isotopic enrichment as a function of the Péclet effect. We suggest that future studies should include relative apoplastic water content in isotopic models.

  3. Are leaf physiological traits related to leaf water isotopic enrichment in restinga woody species?

    Science.gov (United States)

    Rosado, Bruno H P; De Mattos, Eduardo A; Sternberg, Leonel Da S L

    2013-09-01

    During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different enrichments between cells, and different pools of water within leaves, due to morpho-physiological traits, might lead to inaccuracies in isotopic models predicting leaf water enrichment. We evaluate the role of leaf morpho-physiological traits on leaf water isotopic enrichment in woody species occurring in a coastal vegetation of Brazil known as restinga. Hydrogen and oxygen stable isotope values of soil, plant stem and leaf water and leaf traits were measured in six species from restinga vegetation during a drought and a wet period. Leaf water isotopic enrichment relative to stem water was more homogeneous among species during the drought in contrast to the wet period suggesting convergent responses to deal to temporal heterogeneity in water availability. Average leaf water isotopic enrichment relative to stem water during the drought period was highly correlated with relative apoplastic water content. We discuss this observation in the context of current models of leaf water isotopic enrichment as a function of the Péclet effect. We suggest that future studies should include relative apoplastic water content in isotopic models.

  4. Leaf habit and woodiness regulate different leaf economy traits at a given nutrient supply.

    Science.gov (United States)

    Ordoñez, Jenny C; van Bodegom, Peter M; Witte, Jan-Philip M; Bartholomeus, Ruud P; van Dobben, Han F; Aerts, Rien

    2010-11-01

    The large variation in the relationships between environmental factors and plant traits observed in natural communities exemplifies the alternative solutions that plants have developed in response to the same environmental limitations. Qualitative attributes, such as growth form, woodiness, and leaf habit can be used to approximate these alternative solutions. Here, we quantified the extent to which these attributes affect leaf trait values at a given resource supply level, using measured plant traits from 105 different species (254 observations) distributed across 50 sites in mesic to wet plant communities in The Netherlands. For each site, soil total N, soil total P, and water supply estimates were obtained by field measurements and modeling. Effects of growth forms, woodiness, and leaf habit on relations between leaf traits (SLA, specific leaf area; LNC, leaf nitrogen concentration; and LPC, leaf phosphorus concentration) vs. nutrient and water supply were quantified using maximum-likelihood methods and Bonferroni post hoc tests. The qualitative attributes explained 8-23% of the variance within sites in leaf traits vs. soil fertility relationships, and therefore they can potentially be used to make better predictions of global patterns of leaf traits in relation to nutrient supply. However, at a given soil fertility, the strength of the effect of each qualitative attribute was not the same for all leaf traits. These differences may imply a differential regulation of the leaf economy traits at a given nutrient supply, in which SLA and LPC seem to be regulated in accordance to changes in plant size and architecture while LNC seems to be primarily regulated at the leaf level by factors related to leaf longevity.

  5. Leaf wetness distribution within a potato crop

    Science.gov (United States)

    Heusinkveld, B. G.

    2010-07-01

    The Netherlands has a mild maritime climate and therefore the major interest in leaf wetness is associated with foliar plant diseases. During moist micrometeorological conditions (i.e. dew, fog, rain), foliar fungal diseases may develop quickly and thereby destroy a crop quickly. Potato crop monocultures covering several hectares are especially vulnerable to such diseases. Therefore understanding and predicting leaf wetness in potato crops is crucial in crop disease control strategies. A field experiment was carried out in a large homogeneous potato crop in the Netherlands during the growing season of 2008. Two innovative sensor networks were installed as a 3 by 3 grid at 3 heights covering an area of about 2 hectares within two larger potato crops. One crop was located on a sandy soil and one crop on a sandy peat soil. In most cases leaf wetting starts in the top layer and then progresses downward. Leaf drying takes place in the same order after sunrise. A canopy dew simulation model was applied to simulate spatial leaf wetness distribution. The dew model is based on an energy balance model. The model can be run using information on the above-canopy wind speed, air temperature, humidity, net radiation and within canopy air temperature, humidity and soil moisture content and temperature conditions. Rainfall was accounted for by applying an interception model. The results of the dew model agreed well with the leaf wetness sensors if all local conditions were considered. The measurements show that the spatial correlation of leaf wetness decreases downward.

  6. Development and application of triple antibody sandwich enzyme-linked immunosorbent assays for begomovirus detection using monoclonal antibodies against Tomato yellow leaf curl Thailand virus.

    Science.gov (United States)

    Seepiban, Channarong; Charoenvilaisiri, Saengsoon; Warin, Nuchnard; Bhunchoth, Anjana; Phironrit, Namthip; Phuangrat, Bencharong; Chatchawankanphanich, Orawan; Attathom, Supat; Gajanandana, Oraprapai

    2017-05-30

    Tomato yellow leaf curl Thailand virus, TYLCTHV, is a begomovirus that causes severe losses of tomato crops in Thailand as well as several countries in Southeast and East Asia. The development of monoclonal antibodies (MAbs) and serological methods for detecting TYLCTHV is essential for epidemiological studies and screening for virus-resistant cultivars. The recombinant coat protein (CP) of TYLCTHV was expressed in Escherichia coli and used to generate MAbs against TYLCTHV through hybridoma technology. The MAbs were characterized and optimized to develop triple antibody sandwich enzyme-linked immunosorbent assays (TAS-ELISAs) for begomovirus detection. The efficiency of TAS-ELISAs for begomovirus detection was evaluated with tomato, pepper, eggplant, okra and cucurbit plants collected from several provinces in Thailand. Molecular identification of begomoviruses in these samples was also performed through PCR and DNA sequence analysis of the CP gene. Two MAbs (M1 and D2) were generated and used to develop TAS-ELISAs for begomovirus detection. The results of begomovirus detection in 147 field samples indicated that MAb M1 reacted with 2 begomovirus species, TYLCTHV and Tobacco leaf curl Yunnan virus (TbLCYnV), whereas MAb D2 reacted with 4 begomovirus species, TYLCTHV, TbLCYnV, Tomato leaf curl New Delhi virus (ToLCNDV) and Squash leaf curl China virus (SLCCNV). Phylogenetic analyses of CP amino acid sequences from these begomoviruses revealed that the CP sequences of begomoviruses recognized by the narrow-spectrum MAb M1 were highly conserved, sharing 93% identity with each other but only 72-81% identity with MAb M1-negative begomoviruses. The CP sequences of begomoviruses recognized by the broad-spectrum MAb D2 demonstrated a wider range of amino acid sequence identity, sharing 78-96% identity with each other and 72-91% identity with those that were not detected by MAb D2. TAS-ELISAs using the narrow-specificity MAb M1 proved highly efficient for the detection of

  7. Control biológico de enfermedades mediante el tratamiento de semillas de cucurbitáceas con rizobacterias promotoras del crecimiento de las plantas (PGPR./Biological control of diseases by cucurbits seeds treatment with rhizobacteria plant growth promoting (PGPR.

    Directory of Open Access Journals (Sweden)

    Gilda Jiménez Montejo

    2014-01-01

    Full Text Available Resumen:Las regulaciones sobre la producción de alimentos sanos limitan actualmente el uso de fungicidas sintéticos para el tratamiento de semillas y, por otra parte, no se dispone de bactericidas efectivos. Se condujeron experimentos en condiciones controladas para evaluar el efecto de las cepas de rizobacterias antagonistas Bacillus subtilis F16/95, B. subtilis Xph y Pseudomonas putida 14A en el control biológico de la Mancha bacteriana de las cucurbitáceas, la Mancha bacteriana del fruto de melón y la pudrición de la raíz, provocadas por Xanthomonas cucurbitae, Acidovorax avenae subsp. citrulli y Fusarium oxysporum, respectivamente. Se realizó el tratamiento de semillas de pepino (C. sativus, L. var. Poinsett, calabaza (Cucurbita moschata, Duch. var. INIVIT C-88, y melón de Castilla (Cucumis melo, L. var. Hale’s Best. Los tratamientos biológicos mostraron una reducción en la incidencia de las enfermedades e incrementos de longitud del tallo y peso fresco de hojas y raíces, en todas las interacciones planta-patógeno-antagonista. La colonización de raíces alcanzó rangos de 8,9-8,0 y 7,8-7,0 log (ufc cm-1 de raíz a los 4 y 15 días después de la siembra. Estos resultados caracterizaron las cepas aplicadas como rizobacterias promotoras del crecimiento vegetal (PGPR y aconsejan la realización de ensayos de campo./Abstract:Nowadays the regulations about the production of healthy foods limit the use of synthetic fungicides for seeds treatment and, on the other hand, effective bactericides are not available. Experiments under controlled conditions were conducted to evaluate the effect of rhizobacterial antagonistic strains Bacillus subtilis F16/95, B. subtilis Xph and Pseudomonas putida 14A on the biological control of Cucurbits bacterial spot, Watermelon bacterial fruit blotch and Fusarium root rot caused by Xanthomonas cucurbitae, Acidovorax avenae subsp. citrulli and Fusarium oxysporum, respectively. Cucumber (Cucumis sativus

  8. Evaluation of Methane from Sisal Leaf Residue and Palash Leaf Litter

    Science.gov (United States)

    Arisutha, S.; Baredar, P.; Deshpande, D. M.; Suresh, S.

    2014-12-01

    The aim of this study is to evaluate methane production from sisal leaf residue and palash leaf litter mixed with different bulky materials such as vegetable market waste, hostel kitchen waste and digested biogas slurry in a laboratory scale anaerobic reactor. The mixture was prepared with 1:1 proportion. Maximum methane content of 320 ml/day was observed in the case of sisal leaf residue mixed with vegetable market waste as the feed. Methane content was minimum (47 ml/day), when palash leaf litter was used as feed. This was due to the increased content of lignin and polyphenol in the feedstock which were of complex structure and did not get degraded directly by microorganisms. Sisal leaf residue mixtures also showed highest content of volatile fatty acids (VFAs) as compared to palash leaf litter mixtures. It was observed that VFA concentration in the digester first increased, reached maximum (when pH was minimum) and then decreased.

  9. 7 CFR 30.31 - Classification of leaf tobacco.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Classification of leaf tobacco. 30.31 Section 30.31... REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.31 Classification of leaf tobacco. For the purpose of this classification leaf tobacco shall...

  10. What Is a Leaf? An Online Tutorial and Tests

    Science.gov (United States)

    Burrows, Geoffrey

    2008-01-01

    A leaf is a fundamental unit in botany and understanding what constitutes a leaf is fundamental to many plant science activities. My observations and subsequent testing indicated that many students could not confidently and consistently recognise a leaf from a leaflet, or recognise basic leaf arrangements and the various types of compound or…

  11. Effects of some growth regulating applications on leaf yield, raw ...

    African Journals Online (AJOL)

    This study investigated the effects of repetitive applications of herbagreen (HG), humic acid (HA), combined foliar fertilizer (CFF) and HG+CFF performed in the Müsküle grape variety grafted on 5 BB rootstock on fresh or pickled leaf size and leaf raw cellulose content. HA application increased leaf area and leaf water ...

  12. PHARMACOGNOSITIC STUDIES OF THE LEAF AND STEMBARK ...

    African Journals Online (AJOL)

    PHARMACOGNOSITIC STUDIES OF THE LEAF AND STEMBARK OF STEGANOTAENIA ARALIACEAE HOCHST. Z Mohammed, M Shok, EM Abdurahman. Abstract. Microscopical investigation of the powdered leaves and stembark of Steganotaenia araliaceae (family Umbelliferae) shows the presence of anisocytic ...

  13. Leaf anatomical traits determine the 18O enrichment of leaf water in coastal halophytes

    Science.gov (United States)

    Liang, J.; Lin, G., Sr.; Sternberg, L. O.

    2017-12-01

    Foliar anatomical adaptations to high-salinity environment in mangroves may be recorded by leaf water isotopes. Recent studies observed that a few mangrove species have lower 18O enrichment of leaf water (ΔL) relative to source water than the adjacent terrestrial trees, but what factors actually control this phenomenon is still disputable at present. To resolve this issue, we collected 15 species of true mangrove plants, 14 species of adjacent freshwater trees and 4 species of semi-mangrove plants at five study sites on the southeastern coast of China. Leaf stomatal density and pore size, water content, ΔL and other related leaf physiological traits were determined for the selected leaves of these plants. Our results confirmed that ΔL values of mangroves were generally 3 4 ‰ lower than those of the adjacent freshwater or semi-mangrove species. Higher leaf water per area (LWC) and lower leaf stomatal density (LS) of mangroves played co-dominant roles in lowering ΔL through elongating effective leaf mixing length by about 20%. The Péclet model incorporated by LWC and LS performed well in predicting ΔL. The demonstrated general law between leaf anatomy and ΔL in this paper based on a large pool of species bridges the gap between leaf functional traits and metabolic proxies derived ΔL, which will have considerable potential applications in vegetation succession and reconstruction of paleoclimate research.

  14. Wind increases leaf water use efficiency.

    Science.gov (United States)

    Schymanski, Stanislaus J; Or, Dani

    2016-07-01

    A widespread perception is that, with increasing wind speed, transpiration from plant leaves increases. However, evidence suggests that increasing wind speed enhances carbon dioxide (CO2 ) uptake while reducing transpiration because of more efficient convective cooling (under high solar radiation loads). We provide theoretical and experimental evidence that leaf water use efficiency (WUE, carbon uptake per water transpired) commonly increases with increasing wind speed, thus improving plants' ability to conserve water during photosynthesis. Our leaf-scale analysis suggests that the observed global decrease in near-surface wind speeds could have reduced WUE at a magnitude similar to the increase in WUE attributed to global rise in atmospheric CO2 concentrations. However, there is indication that the effect of long-term trends in wind speed on leaf gas exchange may be compensated for by the concurrent reduction in mean leaf sizes. These unintuitive feedbacks between wind, leaf size and water use efficiency call for re-evaluation of the role of wind in plant water relations and potential re-interpretation of temporal and geographic trends in leaf sizes. © 2015 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  15. Leaf Area Estimation Models for Ginger ( Zingibere officinale Rosc ...

    African Journals Online (AJOL)

    The study was carried out to develop leaf area estimation models for three cultivars (37/79, 38/79 and 180/73) and four accessions (29/86, 30/86, 47/86 and 52/86) of ginger. Significant variations were observed among the tested genotypes in leaf length (L), leaf width (W) and actual leaf area (ALA). Leaf area was highly ...

  16. Final report on the safety assessment of AloeAndongensis Extract, Aloe Andongensis Leaf Juice,aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice,aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract.

    Science.gov (United States)

    2007-01-01

    Plant materials derived from the Aloe plant are used as cosmetic ingredients, including Aloe Andongensis Extract, Aloe Andongensis Leaf Juice, Aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract. These ingredients function primarily as skin-conditioning agents and are included in cosmetics only at low concentrations. The Aloe leaf consists of the pericyclic cells, found just below the plant's skin, and the inner central area of the leaf, i.e., the gel, which is used for cosmetic products. The pericyclic cells produce a bitter, yellow latex containing a number of anthraquinones, phototoxic compounds that are also gastrointestinal irritants responsible for cathartic effects. The gel contains polysaccharides, which can be acetylated, partially acetylated, or not acetylated. An industry established limit for anthraquinones in aloe-derived material for nonmedicinal use is 50 ppm or lower. Aloe-derived ingredients are used in a wide variety of cosmetic product types at concentrations of raw material that are 0.1% or less, although can be as high as 20%. The concentration of Aloe in the raw material also may vary from 100% to a low of 0.0005%. Oral administration of various anthraquinone components results in a rise in their blood concentrations, wide systemic distribution, accumulation in the liver and kidneys, and excretion in urine and feces; polysaccharide components are distributed systemically and metabolized into smaller molecules. aloe-derived material has fungicidal, antimicrobial, and antiviral activities, and has been effective in wound healing and infection treatment in animals. Aloe barbadensis (also known as Aloe vera)-derived ingredients were not toxic

  17. Estimating leaf area and leaf biomass of open-grown deciduous urban trees

    Science.gov (United States)

    David J. Nowak

    1996-01-01

    Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

  18. NARROW LEAF 7 controls leaf shape mediated by auxin in rice

    NARCIS (Netherlands)

    Fujino, Kenji; Matsuda, Yasuyuki; Ozawa, Kenjirou; Nishimura, Takeshi; Koshiba, Tomokazu; Fraaije, Marco W.; Sekiguchi, Hiroshi

    Elucidation of the genetic basis of the control of leaf shape could be of use in the manipulation of crop traits, leading to more stable and increased crop production. To improve our understanding of the process controlling leaf shape, we identified a mutant gene in rice that causes a significant

  19. Measurement for the MLC leaf velocity profile by considering the leaf leakage using a radiographic film

    International Nuclear Information System (INIS)

    Chow, James C L; Grigorov, Grigor N

    2006-01-01

    A method to measure the velocity profile of a multi-leaf collimator (MLC) leaf along its travel range using a radiographic film is reported by considering the intra-leaf leakage. A specific dynamic MLC field with leaves travelling from the field edge to the isocentre line was designed. The field was used to expose a radiographic film, which was then scanned, and the dose profile along the horizontal leaf axis was measured. The velocity at a sampling point on the film can be calculated by considering the horizontal distance between the sampling point and the isocentre line, dose at the sampling point, dose rate of the linear accelerator, the total leaf travel time from the field edge to isocentre line and the pre-measured dose rate of leaf leakage. With the leaf velocities and velocity profiles for all MLC leaves measured routinely, a comprehensive and simple QA for the MLC can be set up to test the consistency of the leaf velocity performance which is essential to the IMRT delivery using a sliding window technique. (note)

  20. Effect of nitrogen supply on leaf growth, leaf nitrogen economy and photosynthetic capacity in potato

    NARCIS (Netherlands)

    Vos, J.; Putten, van der P.E.L.

    1998-01-01

    Literature reports show little effect of nitrogen supply on radiation use efficiency in potato and in other dicotyledonous C3 species. This paper tests the hypothesis that potato reduces leaf size rather than leaf nitrogen concentration and photosynthetic capacity when nitrogen is in short supply.

  1. Prophylactic effect of paw-paw leaf and bitter leaf extracts on the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... (ANOVA) and significant means separated using FLSD = LSD procedure as outlined in Obi (2002). RESULTS AND DISCUSSION. In pre-soaking, paw-paw leaf (PL) extract had no significant effect (P > 0.05) on the disease incidence at. 50% anthesis. Bitter leaf (BL) extract had a high signifi- cant effect (P ...

  2. How do leaf veins influence the worldwide leaf economic spectrum? Review and synthesis.

    Science.gov (United States)

    Sack, Lawren; Scoffoni, Christine; John, Grace P; Poorter, Hendrik; Mason, Chase M; Mendez-Alonzo, Rodrigo; Donovan, Lisa A

    2013-10-01

    Leaf vein traits are implicated in the determination of gas exchange rates and plant performance. These traits are increasingly considered as causal factors affecting the 'leaf economic spectrum' (LES), which includes the light-saturated rate of photosynthesis, dark respiration, foliar nitrogen concentration, leaf dry mass per area (LMA) and leaf longevity. This article reviews the support for two contrasting hypotheses regarding a key vein trait, vein length per unit leaf area (VLA). Recently, Blonder et al. (2011, 2013) proposed that vein traits, including VLA, can be described as the 'origin' of the LES by structurally determining LMA and leaf thickness, and thereby vein traits would predict LES traits according to specific equations. Careful re-examination of leaf anatomy, published datasets, and a newly compiled global database for diverse species did not support the 'vein origin' hypothesis, and moreover showed that the apparent power of those equations to predict LES traits arose from circularity. This review provides a 'flux trait network' hypothesis for the effects of vein traits on the LES and on plant performance, based on a synthesis of the previous literature. According to this hypothesis, VLA, while virtually independent of LMA, strongly influences hydraulic conductance, and thus stomatal conductance and photosynthetic rate. We also review (i) the specific physiological roles of VLA; (ii) the role of leaf major veins in influencing LES traits; and (iii) the role of VLA in determining photosynthetic rate per leaf dry mass and plant relative growth rate. A clear understanding of leaf vein traits provides a new perspective on plant function independently of the LES and can enhance the ability to explain and predict whole plant performance under dynamic conditions, with applications towards breeding improved crop varieties.

  3. BOREAS TE-9 NSA Leaf Chlorophyll Density

    Science.gov (United States)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Margolis, Hank; Sy, Mikailou

    2000-01-01

    The BOREAS TE-9 team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. These data were collected to help provide an explanation of potential seasonal and spatial changes of leaf pigment properties in boreal forest species at the NSA. At different dates (FFC-Winter, FFC-Thaw, IFC-1, IFC-2, and IMC-3), foliage samples were collected from the upper third of the canopy for five NSA sites (YJP, OJP, OBS, UBS, and OA) near Thompson, Manitoba. Subsamples of 100 needles for black spruce, 20 needles for jack pine, and single leaf for trembling aspen were cut into pieces and immersed in a 20-mL DMF aliquot in a Nalgene test tube. The extracted foliage materials were then oven-dried at 68 C for 48 hours and weighed. Extracted leaf dry weight was converted to a total leaf area basis to express the chlorophyll content in mg/sq cm of total leaf area. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  4. Leaf and stem morphoanatomy of Petiveria alliacea.

    Science.gov (United States)

    Duarte, M R; Lopes, J F

    2005-12-01

    Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.

  5. Global variability in leaf respiration in relation to climate and leaf traits

    Science.gov (United States)

    Atkin, Owen K.

    2015-04-01

    Leaf respiration plays a vital role in regulating ecosystem functioning and the Earth's climate. Because of this, it is imperative that that Earth-system, climate and ecosystem-level models be able to accurately predict variations in rates of leaf respiration. In the field of photosynthesis research, the F/vC/B model has enabled modellers to accurately predict variations in photosynthesis through time and space. By contrast, we lack an equivalent biochemical model to predict variations in leaf respiration. Consequently, we need to rely on phenomenological approaches to model variations in respiration across the Earth's surface. Such approaches require that we develop a thorough understanding of how rates of respiration vary among species and whether global environmental gradients play a role in determining variations in leaf respiration. Dealing with these issues requires that data sets be assembled on rates of leaf respiration in biomes across the Earth's surface. In this talk, I will use a newly-assembled global database on leaf respiration and associated traits (including photosynthesis) to highlight variation in leaf respiration (and the balance between respiration and photosynthesis) across global gradients in growth temperature and aridity.

  6. Mueller matrix of a dicot leaf

    Science.gov (United States)

    Vanderbilt, Vern C.; Daughtry, Craig S. T.

    2012-06-01

    A better understanding of the information contained in the spectral, polarized bidirectional reflectance and transmittance of leaves may lead to improved techniques for identifying plant species in remotely sensed imagery as well as better estimates of plant moisture and nutritional status. Here we report an investigation of the optical polarizing properties of several leaves of one species, Cannabis sativa, represented by a 3x3 Mueller matrix measured over the wavelength region 400-2,400 nm. Our results support the hypothesis that the leaf surface alters the polarization of incident light - polarizing off nadir, unpolarized incident light, for example - while the leaf volume tends to depolarized incident polarized light.

  7. Induced leaf variations in faba bean

    International Nuclear Information System (INIS)

    Yasin, M.

    1996-01-01

    The frequency and spectrum of M2 chlorophyll and other leaf mutations after gamma ray, ethyl methane sulfonate (EMS) and nitrous oxide (N2O) seed treatment in two varieties of faba bean were studied. In general, cv JV1 was more sensitive and EMS treatment was most effective. The frequency of chlorina-type mutations was higher than that of xantha and chlorotica type chlorophyll mutations. The highest frequency of variations was observed in leaflet texture, followed by arrangement, shape and size in both varieties. The use of these leaf mutations in formulating an ideotype of Vicia faba L. are discussed

  8. Phyllotaxis involves auxin drainage through leaf primordia

    DEFF Research Database (Denmark)

    Deb, Yamini; Marti, Dominik; Frenz, Martin

    2015-01-01

    The spatial arrangement of leaves and flowers around the stem, known as phyllotaxis, is controlled by an auxin-dependent reiterative mechanism that leads to regular spacing of the organs and thereby to remarkably precise phyllotactic patterns. The mechanism is based on the active cellular transport...... of phyllotaxis invoke the accumulation of auxin at leaf initials and removal of auxin through their developing vascular strand, the midvein. We have developed a precise microsurgical tool to ablate the midvein at high spatial and temporal resolution in order to test its function in leaf formation and phyllotaxis...

  9. Leaf density explains variation in leaf mass per area in rice between cultivars and nitrogen treatments.

    Science.gov (United States)

    Xiong, Dongliang; Wang, Dan; Liu, Xi; Peng, Shaobing; Huang, Jianliang; Li, Yong

    2016-05-01

    Leaf mass per area (LMA) is an important leaf trait; however, correlations between LMA and leaf anatomical features and photosynthesis have not been fully investigated, especially in cereal crops. The objectives of this study were (a) to investigate the correlations between LMA and leaf anatomical traits; and (b) to clarify the response of LMA to nitrogen supply and its effect on photosynthetic nitrogen use efficiency (PNUE). In the present study, 11 rice varieties were pot grown under sufficient nitrogen (SN) conditions, and four selected rice cultivars were grown under low nitrogen (LN) conditions. Leaf anatomical traits, gas exchange and leaf N content were measured. There was large variation in LMA across selected rice varieties. Regression analysis showed that the variation in LMA was more closely related to leaf density (LD) than to leaf thickness (LT). LMA was positively related to the percentage of mesophyll tissue area (%mesophyll), negatively related to the percentage of epidermis tissue area (%epidermis) and unrelated to the percentage of vascular tissue area (%vascular). The response of LMA to N supplementation was dependent on the variety and was also mainly determined by the response of LD to N. Compared with SN, photosynthesis was significantly decreased under LN, while PNUE was increased. The increase in PNUE was more critical in rice cultivars with a higher LMA under SN supply. Leaf density is the major cause of the variation in LMA across rice varieties and N treatments, and an increase in LMA under high N conditions would aggravate the decrease in PNUE. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. SU-F-T-350: Continuous Leaf Optimization (CLO) for IMRT Leaf Sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Long, T; Chen, M; Jiang, S; Lu, W [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: To study a new step-and-shoot IMRT leaf sequencing model that avoids the two main pitfalls of conventional leaf sequencing: (1) target fluence being stratified into a fixed number of discrete levels and/or (2) aperture leaf positions being restricted to a discrete set of locations. These assumptions induce error into the sequence or reduce the feasible region of potential plans, respectively. Methods: We develop a one-dimensional (single leaf pair) methodology that does not make assumptions (1) or (2) that can be easily extended to a multi-row model. The proposed continuous leaf optimization (CLO) methodology takes in an existing set of apertures and associated intensities, or solution “seed,” and improves the plan without the restrictiveness of 1or (2). It then uses a first-order descent algorithm to converge onto a locally optimal solution. A seed solution can come from models that assume (1) and (2), thus allowing the CLO model to improve upon existing leaf sequencing methodologies. Results: The CLO model was applied to 208 generated target fluence maps in one dimension. In all cases for all tested sequencing strategies, the CLO model made improvements on the starting seed objective function. The CLO model also was able to keep MUs low. Conclusion: The CLO model can improve upon existing leaf sequencing methods by avoiding the restrictions of (1) and (2). By allowing for more flexible leaf positioning, error can be reduced when matching some target fluence. This study lays the foundation for future models and solution methodologies that can incorporate continuous leaf positions explicitly into the IMRT treatment planning model. Supported by Cancer Prevention & Research Institute of Texas (CPRIT) - ID RP150485.

  11. Simulated Acid Rain-induced Alterations in Flowering, Leaf ...

    African Journals Online (AJOL)

    Evaluation of SAR effects on budding, flowering, leaf abscission and pollen development revealed that ... Keywords: Simulated acid rain, Helianthus annuus, flowering, leaf abscission, pollen germination, sunflower. ... HOW TO USE AJOL.

  12. Primate numts and reticulate evolution of capped and golden leaf ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    A recent phylogenetic study of langurs and leaf monkeys of South Asia suggested a reticulate evolution of capped and golden leaf ..... Accordingly, transversions were weighted .... lineages. Most taxonomic schemes published till date place.

  13. Performance of broiler chickens fed on Moringa oleifera leaf meal ...

    African Journals Online (AJOL)

    Performance of broiler chickens fed on Moringa oleifera leaf meal ... This exploratory study was conducted to investigate the effect of Moringa oleifera leaf meal ... ratio were evaluated for the individual replicate of each dietary treatment.

  14. Antibacterial Activity of Vernonia amygdalina Leaf Extracts against ...

    African Journals Online (AJOL)

    ADOWIE PERE

    (Bitter leaf), Allium sativum (Garlic), O. gratissimum. (Scent leaf) ... complex active components that are useful ... hydroxide was added. .... KEY: CPX-Ciprofloxacin, Ro-Rocephin, St-Streptomycin, AU-Augmentin, SXT-Septrin, SP- Sparfloxacin, ...

  15. Effect of Wind on the Relation of Leaf N, P Stoichiometry with Leaf Morphology in Quercus Species

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2018-02-01

    Full Text Available Leaf nitrogen (N and phosphorus (P stoichiometry correlates closely to leaf morphology, which is strongly impacted by wind at multiple scales. However, it is not clear how leaf N, P stoichiometry and its relationship to leaf morphology changes with wind load. We determined the leaf N and P concentrations and leaf morphology—including specific leaf area (SLA and leaf dissection index (LDI—for eight Quercus species under a simulated wind load for seven months. Leaf N and P concentrations increased significantly under these conditions for Quercus acutissima, Quercus rubra, Quercus texana, and Quercus palustris—which have elliptic leaves—due to their higher N, P requirements and a resultant leaf biomass decrease, which is a tolerance strategy for Quercus species under a wind load. Leaf N:P was relatively stable under wind for all species, which supports stoichiometric homeostasis. Leaf N concentrations showed a positive correlation to SLA, leaf N and P concentrations showed positive correlations to LDI under each wind treatment, and the slope of correlations was not affected by wind, which indicates synchronous variations between leaf stoichiometry and leaf morphology under wind. However, the intercept of correlations was affected by wind, and leaf N and P use efficiency decreased under the wind load, which suggests that the Quercus species changes from “fast investment-return” in the control to “slow investment-return” under windy conditions. These results will be valuable to understanding functional strategies for plants under varying wind loads, especially synchronous variations in leaf traits along a wind gradient.

  16. The complete genomic sequence of pepper yellow leaf curl virus (PYLCV and its implications for our understanding of evolution dynamics in the genus polerovirus.

    Directory of Open Access Journals (Sweden)

    Aviv Dombrovsky

    Full Text Available We determined the complete sequence and organization of the genome of a putative member of the genus Polerovirus tentatively named Pepper yellow leaf curl virus (PYLCV. PYLCV has a wider host range than Tobacco vein-distorting virus (TVDV and has a close serological relationship with Cucurbit aphid-borne yellows virus (CABYV (both poleroviruses. The extracted viral RNA was subjected to SOLiD next-generation sequence analysis and used as a template for reverse transcription synthesis, which was followed by PCR amplification. The ssRNA genome of PYLCV includes 6,028 nucleotides encoding six open reading frames (ORFs, which is typical of the genus Polerovirus. Comparisons of the deduced amino acid sequences of the PYLCV ORFs 2-4 and ORF5, indicate that there are high levels of similarity between these sequences to ORFs 2-4 of TVDV (84-93% and to ORF5 of CABYV (87%. Both PYLCV and Pepper vein yellowing virus (PeVYV contain sequences that point to a common ancestral polerovirus. The recombination breakpoint which is located at CABYV ORF3, which encodes the viral coat protein (CP, may explain the CABYV-like sequences found in the genomes of the pepper infecting viruses PYLCV and PeVYV. Two additional regions unique to PYLCV (PY1 and PY2 were identified between nucleotides 4,962 and 5,061 (ORF 5 and between positions 5,866 and 6,028 in the 3' NCR. Sequence analysis of the pepper-infecting PeVYV revealed three unique regions (Pe1-Pe3 with no similarity to other members of the genus Polerovirus. Genomic analyses of PYLCV and PeVYV suggest that the speciation of these viruses occurred through putative recombination event(s between poleroviruses co-infecting a common host(s, resulting in the emergence of PYLCV, a novel pathogen with a wider host range.

  17. The complete genomic sequence of pepper yellow leaf curl virus (PYLCV) and its implications for our understanding of evolution dynamics in the genus polerovirus.

    Science.gov (United States)

    Dombrovsky, Aviv; Glanz, Eyal; Lachman, Oded; Sela, Noa; Doron-Faigenboim, Adi; Antignus, Yehezkel

    2013-01-01

    We determined the complete sequence and organization of the genome of a putative member of the genus Polerovirus tentatively named Pepper yellow leaf curl virus (PYLCV). PYLCV has a wider host range than Tobacco vein-distorting virus (TVDV) and has a close serological relationship with Cucurbit aphid-borne yellows virus (CABYV) (both poleroviruses). The extracted viral RNA was subjected to SOLiD next-generation sequence analysis and used as a template for reverse transcription synthesis, which was followed by PCR amplification. The ssRNA genome of PYLCV includes 6,028 nucleotides encoding six open reading frames (ORFs), which is typical of the genus Polerovirus. Comparisons of the deduced amino acid sequences of the PYLCV ORFs 2-4 and ORF5, indicate that there are high levels of similarity between these sequences to ORFs 2-4 of TVDV (84-93%) and to ORF5 of CABYV (87%). Both PYLCV and Pepper vein yellowing virus (PeVYV) contain sequences that point to a common ancestral polerovirus. The recombination breakpoint which is located at CABYV ORF3, which encodes the viral coat protein (CP), may explain the CABYV-like sequences found in the genomes of the pepper infecting viruses PYLCV and PeVYV. Two additional regions unique to PYLCV (PY1 and PY2) were identified between nucleotides 4,962 and 5,061 (ORF 5) and between positions 5,866 and 6,028 in the 3' NCR. Sequence analysis of the pepper-infecting PeVYV revealed three unique regions (Pe1-Pe3) with no similarity to other members of the genus Polerovirus. Genomic analyses of PYLCV and PeVYV suggest that the speciation of these viruses occurred through putative recombination event(s) between poleroviruses co-infecting a common host(s), resulting in the emergence of PYLCV, a novel pathogen with a wider host range.

  18. Variable depth recursion algorithm for leaf sequencing

    International Nuclear Information System (INIS)

    Siochi, R. Alfredo C.

    2007-01-01

    The processes of extraction and sweep are basic segmentation steps that are used in leaf sequencing algorithms. A modified version of a commercial leaf sequencer changed the way that the extracts are selected and expanded the search space, but the modification maintained the basic search paradigm of evaluating multiple solutions, each one consisting of up to 12 extracts and a sweep sequence. While it generated the best solutions compared to other published algorithms, it used more computation time. A new, faster algorithm selects one extract at a time but calls itself as an evaluation function a user-specified number of times, after which it uses the bidirectional sweeping window algorithm as the final evaluation function. To achieve a performance comparable to that of the modified commercial leaf sequencer, 2-3 calls were needed, and in all test cases, there were only slight improvements beyond two calls. For the 13 clinical test maps, computation speeds improved by a factor between 12 and 43, depending on the constraints, namely the ability to interdigitate and the avoidance of the tongue-and-groove under dose. The new algorithm was compared to the original and modified versions of the commercial leaf sequencer. It was also compared to other published algorithms for 1400, random, 15x15, test maps with 3-16 intensity levels. In every single case the new algorithm provided the best solution

  19. ANTIFUNGAL ACTIVITY OF ETHANOLIC LEAF EXTRACT OF ...

    African Journals Online (AJOL)

    Ethanolic leaf extract of Eucalyptus camaldulensis, dispersed in a concentrated sugar solution had marked fungicidal effect against clinical dermatophytic fungal isolates; Microsporium gypseum and Trichophyton mentagrophytes. Microsporium gypseum at an inoculum level of 4.8 x 103 cfu/ml and T. mentagrophytes at ...

  20. DIFFERENCES IN LEAF GAS EXCHANGE AND LEAF CHARACTERISTICS BETWEEN TWO ALMOND CULTIVARS

    Directory of Open Access Journals (Sweden)

    George D. Nanos

    2013-12-01

    Full Text Available Leaf chlorophyll content, specific leaf weight (SLW, photosynthetic and transpiration rates, stomatal functioning, water use efficiency and quantum yield were assessed during the kernel filling period for two consecutive years in order to understand tissue-centered physiological profile differences between two commercial almond cultivars, ‘Ferragnès’ and ‘Texas’. Similar SLWs were observed on the studied cultivars; however, chlorophyll content, net photosynthetic and transpiration rates and stomatal functioning demonstrated statistically significant differences. In both cultivars, an overall decline in the examined parameters towards fruit maturation (i.e. end of the summer was recorded. ‘Ferragnès’ leaves were found to be more efficient in leaf photosynthesis related performance during kernel filling, when irrigated sufficiently, in comparison to ‘Texas’ leaves. Low average values of leaf conductance during summer in ‘Texas’ leaves revealed its potential for adaptation in cool climates and increased carbon assimilation therein for high kernel yield.

  1. Short Communication: The developmentt of a leaf tensilmeter for in ...

    African Journals Online (AJOL)

    The development of a portable leaf tensilmeter for the in situ measurement of leaf tensile strength is described. Tensile strength is determined by the distortion of strain gauges on modified stripping pliers which are used to break leaf blades. The output is displayed via an analogue chip through a liquid crystal display.

  2. Leaf area prediction models for Tsuga canadensis in Maine

    Science.gov (United States)

    Laura S. Kenefic; R.S. Seymour

    1999-01-01

    Tsuga canadensis (L.) Carr. (eastern hemlock) is a common species throughout the Acadian forest. Studies of leaf area and growth efficiency in this forest type have been limited by the lack of equations to predict leaf area of this species. We found that sapwood area was an effective leaf area surrogate in T. canadensis, though...

  3. Study on creation of an indocalamus leaf flavor

    Directory of Open Access Journals (Sweden)

    Guangyong ZHU

    2015-01-01

    Full Text Available AbstractFlavors represent a small but significant segment of food industry. Sensory characteristics play an important role in the process of consumer acceptance and preference. Indocalamus leaf takes on a pleasant odor and indocalamus leaf flavor can be used in many products. However, indocalamus leaf flavor formula has not been reported. Therefore, developing an indocalamus leaf flavor is of significant interests. Note is a distinct flavor or odor characteristic. This paper concentrates on preparation and creation of indocalamus leaf flavor according to the notes of indocalamus leaf. The notes were obtained by smelling indocalamus leaf, and the results showed that the notes of indocalamus leaf flavor can be classified as: green-leafy note, sweet note, beany note, aldehydic note, waxy note, woody note, roast note, creamy note, and nutty note. According to the notes of indocalamus leaf odor, a typical indocalamus leaf flavor formula was obtained. The indocalamus leaf flavor blended is pleasant, harmonious, and has characteristics of indocalamus leaf odor.

  4. Does leaf chemistry differentially affect breakdown in tropical versus temperate streams? Importance of standardized analytical techniques to measure leaf chemistry

    Science.gov (United States)

    Marcelo Ardon; Catherine M. Pringle; Susan L. Eggert

    2009-01-01

    Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to...

  5. Apparent over-investment in leaf venation relaxes leaf morphological constraints on photosynthesis in arid habitats

    Science.gov (United States)

    de Boer, Hugo; Drake, Paul; Veneklaas, Erik

    2017-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on transpiration, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Critical is that leaf veins supply the mesophyll with water that evaporates when stomata are open to allow CO2 uptake for photosynthesis. Theoretical analyses suggest that water is optimally distributed in the mesophyll when the lateral distance between veins (dx) is equal to the distance from these veins to the epidermis (dy), expressed as dx:dy≈1. Although this theory is supported by observations on many derived angiosperms, we hypothesize that plants in arid environments may reduce dx:dy below unity owing to climate-specific functional adaptations of increased leaf thickness and increased vein density. To test our hypothesis we assembled leaf hydraulic, morphological and photosynthetic traits of 68 species from the Eucalyptus and Corymbia genera (termed eucalypts) along an aridity gradient in southwestern Australia. We inferred the potential gas exchange advantage of reducing dx beyond dy using a model that links leaf morphology and hydraulics to photosynthesis. Our observations reveal that eucalypts in arid environments have thick amphistomatous leaves with high vein densities, resulting in dx:dy ratios that range from 1.6 to 0.15 along the aridity gradient. Our model suggests that as leaves become thicker, the effect of reducing dx beyond dy is to offset the reduction in leaf gas exchange that would result from maintaining dx:dy at unity. This apparent over-investment in leaf venation may be explained from the selective pressure of aridity, under which traits associated with long leaf lifespan, high hydraulic and thermal capacitances, and high potential rates of leaf

  6. Apparent Overinvestment in Leaf Venation Relaxes Leaf Morphological Constraints on Photosynthesis in Arid Habitats1[OPEN

    Science.gov (United States)

    de Boer, Hugo J.; Drake, Paul L.; Wendt, Erin; Price, Charles A.; Schulze, Ernst-Detlef; Turner, Neil C.; Nicolle, Dean

    2016-01-01

    Leaf veins supply the mesophyll with water that evaporates when stomata are open to allow CO2 uptake for photosynthesis. Theoretical analyses suggest that water is optimally distributed in the mesophyll when the lateral distance between veins (dx) is equal to the distance from these veins to the epidermis (dy), expressed as dx:dy ≈ 1. Although this theory is supported by observations of many derived angiosperms, we hypothesize that plants in arid environments may reduce dx:dy below unity owing to climate-specific functional adaptations of increased leaf thickness and increased vein density. To test our hypothesis, we assembled leaf hydraulic, morphological, and photosynthetic traits of 68 species from the Eucalyptus and Corymbia genera (termed eucalypts) along an aridity gradient in southwestern Australia. We inferred the potential gas-exchange advantage of reducing dx beyond dy using a model that links leaf morphology and hydraulics to photosynthesis. Our observations reveal that eucalypts in arid environments have thick amphistomatous leaves with high vein densities, resulting in dx:dy ratios that range from 1.6 to 0.15 along the aridity gradient. Our model suggests that, as leaves become thicker, the effect of reducing dx beyond dy is to offset the reduction in leaf gas exchange that would result from maintaining dx:dy at unity. This apparent overinvestment in leaf venation may be explained from the selective pressure of aridity, under which traits associated with long leaf life span, high hydraulic and thermal capacitances, and high potential rates of leaf water transport confer a competitive advantage. PMID:27784769

  7. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

    Science.gov (United States)

    Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

  8. Joint Leaf chlorophyll and leaf area index retrieval from Landsat data using a regularized model inversion system

    Science.gov (United States)

    Leaf area index (LAI) and leaf chlorophyll (Chl) content represent key biophysical and biochemical controls on water, energy and carbon exchange processes in the terrestrial biosphere. In combination, LAI and leaf Chl content provide critical information on vegetation density, vitality and photosynt...

  9. Does leaf chemistry differentially affect breakdown in tropical vs temperate streams? Importance of standardized analytical techniques to measure leaf chemistry

    Science.gov (United States)

    Marcelo Ard& #243; n; Catherine M. Pringle; Susan L. Eggert

    2009-01-01

    Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to measure leaf chemistry. We used standardized analytical techniques to measure chemistry and breakdown rate of leaves from common riparian tree species at 2 sites, 1...

  10. Molecular Identification of Weed hosts of Tomato yellow leaf curl virus in southeast of Kerman Province

    Directory of Open Access Journals (Sweden)

    Kh. Salari

    2016-02-01

    Full Text Available Introduction Tomato yellow leaf curl virus, TYLCV belongs to the family Geminiviridae and Begomovirus genus (27. In recent years, extensive damage to tomatoes and cucurbits plants in the south and the southeast of Iran has arrived (23. This virus family have circular, and single-stranded DNA genome and are widespread in tropical and subtropical areas (30. They are infected several plant species with economic importance. Begomoviruses are dicot-infecting, whitefly-transmitted viruses with a genome comprised of one or two molecules DNA (5. Up to now, studies have been performed to evaluate the status of distribution, and identification of natural host and assess the genetic diversity, but there is not a comprehensive review about its weed hosts yet. Materials and Methods In this research, The weeds from margins and inside greenhouses and farms of tomato and cucurbit in severely infected areas including Manoojan, Kahnooj, Faryab, Anbrabad and Jiroft to identify weed hosts of the virus in nature, were collected. Identification of collected samples were conducted by botanical specialists. Total DNAs were extracted from leaves according to the method of zhang et al. (1998 and stored at -20 oC. Identification of infected samples were carried out by PCR using degenerate primer pairs PCRv 181/Bc that direct the amplification of˷ 550 bp fragment of mono – and bipartite begomoviruses genome comprising the C-terminal portion of the intergenic region (IR N-terminal portion of the CPgene. PCR were performed in 25 µl reaction volumes containing 1 µl of template DNA, o.5 µl of Taq DNA polymerase Sinaclon (IRAN, 1.2 µl MgCl2, 0.5 µl dNTPs. 1 µM of each forward and reverse primers, 4.3 µl of 10× reaction buffer and 15.5 distilled water. The amplification were performed using a peqSTAR 96x Termal Cycler (Peqlabe, Germany. PCR conditions consisted of initial denaturing 94 oC for 3 min followed by 30 cycles of denaturation at 94 oC for 50s, annealing at

  11. Leaf area index from litter collection: impact of specific leaf area variability within a beech stand

    Energy Technology Data Exchange (ETDEWEB)

    Bouriaud, O. [Inst. National de la Recherche Agronomique, Centre de Recherches Forestieres de Nancy, Champenoux (France); Soudani, K. [Univ. Paris-Sud XI, Dept. d' Ecophysiologie Vegetale, Lab. Ecologie Systematique et Evolution, Orsay Cedex (France); Breda, N. [Inst. National de la Recherche Agronomique, Centre de Recherches Forestieres de Nancy, Champenoux (France)

    2003-06-01

    Litter fall collection is a direct method widely used to estimate leaf area index (LAI) in broad-leaved forest stands. Indirect measurements using radiation transmittance and gap fraction theory are often compared and calibrated against litter fall, which is considered as a reference method, but few studies address the question of litter specific leaf area (SLA) measurement and variability. SLA (leaf area per unit of dry weight, m{sup 2}{center_dot}g{sup -1}) is used to convert dry leaf litter biomass (g .m{sup -}2) into leaf area per ground unit area (m{sup 2}{center_dot}m{sup -2}). We paid special attention to this parameter in two young beech stands (dense and thinned) in northeastern France. The variability of both canopy (closure, LAI) and site conditions (soil properties, vegetation) was investigated as potential contributing factors to beech SLA variability. A systematic description of soil and floristic composition was performed and three types of soil were identified. Ellenberg's indicator values were averaged for each plot to assess nitrogen soil content. SLA of beech litter was measured three times during the fall in 23 plots in the stands (40 ha). Litter was collected bimonthly in square-shaped traps (0.5 m{sup 2}) and dried. Before drying, 30 leaves per plot and for each date were sampled, and leaf length, width, and area were measured with the help of a LI-COR areameter. SLA was calculated as the ratio of cumulated leaf area to total dry weight of the 30 leaves. Leaves characteristics per plot were averaged for the three dates of litter collection. Plant area index (PAI), estimated using the LAI-2000 plant canopy analyser and considering only the upper three rings, ranged from 2.9 to 8.1. Specific leaf area of beech litter was also highly different from one plot to the other, ranging from 150 to 320 cm{sup 2}{center_dot}g{sup -1}. Nevertheless, no relationship was found between SLA and stand canopy closure or PAI On the contrary, a significant

  12. Leaf area index from litter collection: impact of specific leaf area variability within a beech stand

    International Nuclear Information System (INIS)

    Bouriaud, O.; Soudani, K.; Breda, N.

    2003-01-01

    Litter fall collection is a direct method widely used to estimate leaf area index (LAI) in broad-leaved forest stands. Indirect measurements using radiation transmittance and gap fraction theory are often compared and calibrated against litter fall, which is considered as a reference method, but few studies address the question of litter specific leaf area (SLA) measurement and variability. SLA (leaf area per unit of dry weight, m 2 ·g -1 ) is used to convert dry leaf litter biomass (g .m - 2) into leaf area per ground unit area (m 2 ·m -2 ). We paid special attention to this parameter in two young beech stands (dense and thinned) in northeastern France. The variability of both canopy (closure, LAI) and site conditions (soil properties, vegetation) was investigated as potential contributing factors to beech SLA variability. A systematic description of soil and floristic composition was performed and three types of soil were identified. Ellenberg's indicator values were averaged for each plot to assess nitrogen soil content. SLA of beech litter was measured three times during the fall in 23 plots in the stands (40 ha). Litter was collected bimonthly in square-shaped traps (0.5 m 2 ) and dried. Before drying, 30 leaves per plot and for each date were sampled, and leaf length, width, and area were measured with the help of a LI-COR areameter. SLA was calculated as the ratio of cumulated leaf area to total dry weight of the 30 leaves. Leaves characteristics per plot were averaged for the three dates of litter collection. Plant area index (PAI), estimated using the LAI-2000 plant canopy analyser and considering only the upper three rings, ranged from 2.9 to 8.1. Specific leaf area of beech litter was also highly different from one plot to the other, ranging from 150 to 320 cm 2 ·g -1 . Nevertheless, no relationship was found between SLA and stand canopy closure or PAI On the contrary, a significant relationship between SLA and soil properties was observed. Both SLA

  13. Effects of leaf movement on leaf temperature, transpiration and radiation interception in soybean under water stress conditions

    International Nuclear Information System (INIS)

    Isoda, A.; Wang, P.

    2001-01-01

    Varietal differences in leaf movement were examined in terms of radiation interception, leaf temperature and transpiration under water stressed conditions. Five cultivars (Qindou 7232, Gaofei 16, Dongnong 87 - 138, 8285 - 8 and 8874) were grown in a concrete frame field in Xinjiang, China. Irrigation treatments (irrigation and no irrigation) were made from the flowering to the pod filling stage. A leaflet in the uppermost layer of the canopy was restrained horizontally. Leaf temperatures, transpiration rate (stem sap flow rate of the main stem per unit leaf area) and intercepted radiation of each leaflet were measured. There were greater varietal differences in leaf movement, leaf temperature and transpiration rate. Leaf temperature seemed to be adjusted by leaf movement and transpiration. The extent to which is adjusted by leaf movement and transpiration differed among the cultivars; leaf temperature was influenced mainly by leaf movement for Gaofei 16 and Dongnong 87 - 138, mainly by transpiration for Qindou 7232 and 8874, and by both for 8285 - 8. Intercepted radiation in the upper two layers of the canopy (20 cm from the uppermost) was greater in the irrigated plot, although the mean values of total leaflets of the irrigated plot were not different as compared to the non-irrigated plot. Although paraheliotropic leaf movement decreased radiation interception, it offers some possibilities for the improvement in radiation penetration within a dense canopy. Cumulated amount of transpiration during a day was compared between the restrained-leaf and the non-leaf-restrained plants in 8874. Paraheliotropic leaf movement reduced water loss by 23% in the irrigated and 71% in the non-irrigated plots

  14. Use of NAP gene to manipulate leaf senescence in plants

    Science.gov (United States)

    Gan, Susheng; Guo, Yongfeng

    2013-04-16

    The present invention discloses transgenic plants having an altered level of NAP protein compared to that of a non-transgenic plant, where the transgenic plants display an altered leaf senescence phenotype relative to a non-transgenic plant, as well as mutant plants comprising an inactivated NAP gene, where mutant plants display a delayed leaf senescence phenotype compared to that of a non-mutant plant. The present invention also discloses methods for delaying leaf senescence in a plant, as well as methods of making a mutant plant having a decreased level of NAP protein compared to that of a non-mutant plant, where the mutant plant displays a delayed leaf senescence phenotype relative to a non-mutant plant. Methods for causing precocious leaf senescence or promoting leaf senescence in a plant are also disclosed. Also disclosed are methods of identifying a candidate plant suitable for breeding that displays a delayed leaf senescence and/or enhanced yield phenotype.

  15. Preferência da broca-das-cucurbitáceas [Diaphania nitidalis Cramer, 1782 (Lepidoptera: Pyralidae] por cultivares de pepineiro em ambiente protegido Pickleworm [Diaphania nitidalis Cramer, 1782 (Lepidoptera: Pyralidae]preference for cucumber cultivars in greenhouse

    Directory of Open Access Journals (Sweden)

    Giovani Greigh de Brito

    2004-04-01

    Full Text Available A broca-das-cucurbitáceas (Diaphania nitidalis é uma praga de grande importância em diversas culturas, principalmente do pepineiro. Esta espécie pode apresentar preferência em relação a determinadas cultivares quanto à sua alimentação e até mesmo oviposição. Nesse sentido, o presente estudo objetivou avaliar a ocorrência desta praga em frutos de seis cultivares de pepineiro, em ambiente protegido. As cultivares Patton, Victoria, Premier, Vlaspik e Napoleon apresentaram, respectivamente, 50%, 43,75%, 37,50%, 34,37% e 25,87% dos frutos brocados. A cultivar Marinda apresentou resultado promissor, com apenas 10,37% dos frutos com presença de larvas de D. nitidalis.The pickleworm (Diaphania nitidalis is a major pest on different crops, particulary on cucumber. This species has shown a preference for determined cultivars to its feeding and oviposition habits. Thus, the aim of this study was to evaluate the occurence of D. nitidalis larvae in fruits of six cucumber cultivars in greenhouse. The cultivars Patton, Victoria, Premier, Vlaspik and Napoleon showed, respectively, 50%, 43.75%, 37.50%, 34.37% and 25.87% of bored fruits. Promising results were obtained with the cultivar Marinda, which showed only 10.37% of bored fruits.

  16. Leaf endophyte load influences fungal garden development in leaf-cutting ants

    Directory of Open Access Journals (Sweden)

    Van Bael Sunshine A

    2012-11-01

    Full Text Available Abstract Background Previous work has shown that leaf-cutting ants prefer to cut leaf material with relatively low fungal endophyte content. This preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in their host plants’ defense against leaf-cutting ants. To measure the long-term cost to the ant colony of fungal endophytes in their forage material, we conducted a 20-week laboratory experiment to measure fungal garden development for colonies that foraged on leaves with low or high endophyte content. Results Colony mass and the fungal garden dry mass did not differ significantly between the low and high endophyte feeding treatments. There was, however, a marginally significant trend toward greater mass of fungal garden per ant worker in the low relative to the high endophyte treatment. This trend was driven by differences in the fungal garden mass per worker from the earliest samples, when leaf-cutting ants had been foraging on low or high endophyte leaf material for only 2 weeks. At two weeks of foraging, the mean fungal garden mass per worker was 77% greater for colonies foraging on leaves with low relative to high endophyte loads. Conclusions Our data suggest that the cost of endophyte presence in ant forage material may be greatest to fungal colony development in its earliest stages, when there are few workers available to forage and to clean leaf material. This coincides with a period of high mortality for incipient colonies in the field. We discuss how the endophyte-leaf-cutter ant interaction may parallel constitutive defenses in plants, whereby endophytes reduce the rate of colony development when its risk of mortality is greatest.

  17. Comparison of leaf-on and leaf-off ALS data for mapping riparian tree species

    Science.gov (United States)

    Laslier, Marianne; Ba, Antoine; Hubert-Moy, Laurence; Dufour, Simon

    2017-10-01

    Forest species composition is a fundamental indicator of forest study and management. However, describing forest species composition at large scales and of highly diverse populations remains an issue for which remote sensing can provide significant contribution, in particular, Airborne Laser Scanning (ALS) data. Riparian corridors are good examples of highly valuable ecosystems, with high species richness and large surface areas that can be time consuming and expensive to monitor with in situ measurements. Remote sensing could be useful to study them, but few studies have focused on monitoring riparian tree species using ALS data. This study aimed to determine which metrics derived from ALS data are best suited to identify and map riparian tree species. We acquired very high density leaf-on and leaf-off ALS data along the Sélune River (France). In addition, we inventoried eight main riparian deciduous tree species along the study site. After manual segmentation of the inventoried trees, we extracted 68 morphological and structural metrics from both leaf-on and leaf-off ALS point clouds. Some of these metrics were then selected using Sequential Forward Selection (SFS) algorithm. Support Vector Machine (SVM) classification results showed good accuracy with 7 metrics (0.77). Both leaf-on and leafoff metrics were kept as important metrics for distinguishing tree species. Results demonstrate the ability of 3D information derived from high density ALS data to identify riparian tree species using external and internal structural metrics. They also highlight the complementarity of leaf-on and leaf-off Lidar data for distinguishing riparian tree species.

  18. Transcriptional analyses of natural leaf senescence in maize.

    Directory of Open Access Journals (Sweden)

    Wei Yang Zhang

    Full Text Available Leaf senescence is an important biological process that contributes to grain yield in crops. To study the molecular mechanisms underlying natural leaf senescence, we harvested three different developmental ear leaves of maize, mature leaves (ML, early senescent leaves (ESL, and later senescent leaves (LSL, and analyzed transcriptional changes using RNA-sequencing. Three sets of data, ESL vs. ML, LSL vs. ML, and LSL vs. ESL, were compared, respectively. In total, 4,552 genes were identified as differentially expressed. Functional classification placed these genes into 18 categories including protein metabolism, transporters, and signal transduction. At the early stage of leaf senescence, genes involved in aromatic amino acids (AAAs biosynthetic process and transport, cellular polysaccharide biosynthetic process, and the cell wall macromolecule catabolic process, were up-regulated. Whereas, genes involved in amino acid metabolism, transport, apoptosis, and response to stimulus were up-regulated at the late stage of leaf senescence. Further analyses reveals that the transport-related genes at the early stage of leaf senescence potentially take part in enzyme and amino acid transport and the genes upregulated at the late stage are involved in sugar transport, indicating nutrient recycling mainly takes place at the late stage of leaf senescence. Comparison between the data of natural leaf senescence in this study and previously reported data for Arabidopsis implies that the mechanisms of leaf senescence in maize are basically similar to those in Arabidopsis. A comparison of natural and induced leaf senescence in maize was performed. Athough many basic biological processes involved in senescence occur in both types of leaf senescence, 78.07% of differentially expressed genes in natural leaf senescence were not identifiable in induced leaf senescence, suggesting that differences in gene regulatory network may exist between these two leaf senescence

  19. Seasonality of Leaf Carbon Isotopic Composition and Leaf Water Isotopic Enrichment in a Mixed Evergreen Forest in Southern California

    Science.gov (United States)

    Santiago, L. S.; Sickman, J. O.; Goulden, M.; DeVan, C.; Pasquini, S. C.; Pivovaroff, A. L.

    2011-12-01

    Leaf carbon isotopic composition and leaf water isotopic enrichment reflect physiological processes and are important for linking local and regional scale processes to global patterns. We investigated how seasonality affects the isotopic composition of bulk leaf carbon, leaf sugar carbon, and leaf water hydrogen under a Mediterranean climate. Leaf and stem samples were collected monthly from four tree species (Calocedrus decurrens, Pinus lambertiana, Pinus ponderosa, and Quercus chrysolepis) at the James San Jacinto Mountain Reserve in southern California. Mean monthly bulk leaf carbon isotopic composition varied from -34.5 % in P. ponderosa to -24.7 % in P. lambertiana and became more depleted in 13C from the spring to the summer. Mean monthly leaf sugar varied from -29.3 % in P. ponderosa to -21.8 % in P. lambertiana and was enriched in 13C during the winter, spring and autumn, but depleted during the mid-summer. Leaf water hydrogen isotopic composition was 28.4 to 68.8 % more enriched in deuterium than source water and this enrichment was greater as seasonal drought progressed. These data indicate that leaf carbon and leaf water hydrogen isotopic composition provide sensitive measures that connect plant physiological processes to short-term climatic variability.

  20. Air pollutants and the leaf cuticle. Proceedings

    International Nuclear Information System (INIS)

    Percy, K.E.; Jagels, R.; Simpson, C.J.

    1994-01-01

    The leaf surface forms the interface between plants and a deteriorating atmospheric environment. It is, therefore, the first point of contact between plants and air pollutants and presents an effective barrier to pollutant entry. Outermost surfaces of leaves are covered by a thin, lipoidal, non-living membrane called a cuticle. Cuticle integrity is essential to plant survival and has many essential functions, including the prevention of excessive water loss, regulation of solute uptake and protection of sensitive underlying photosynthetic tissues against harmful irradiation such as enhanced UV-B resulting from stratospheric ozone depletion. The physicochemical properties of the cuticle vary greatly between and within species. They are known to be sensitive to change through natural and anthropogenic influences. This book comprises contributions made to a NATO-sponsored Advanced Research Workshop ''Air Pollutants and the Leaf Cuticle'' held October 4-9, 1993 in Fredericton, New Brunswick, Canada. The objective of the ARW was to bring together for the first time international expertise on the subject of air pollutant interactions with the cuticle. In order to facilitate a state-of-science review, the ARW was structured around four themes. They were as follows: 1. Cuticular physicochemical characteristics, physiological, regulatory, and protective roles. 2. Effects, mechanisms, and consequences of air pollutant interaction with leaf cuticles. 3. Non-anthropogenic and environmental influences on the cuticle and potential of the cuticle for biomonitoring and critical levels mapping. 4. New developments in experimental methodology and analytical techniques. (orig./vhe)

  1. [Latitude variation mechanism of leaf traits of Metasequoia glyptostroboides in eastern coastal China].

    Science.gov (United States)

    Guo, Wei Hong; Wang, Hua; Yu, Mu Kui; Wu, Tong Gui; Han, You Zhi

    2017-03-18

    We analyzed the rules of Metasequoia glyptostroboides along with latitude, including leaf length, leaf width, leaf perimeter, leaf area, ratio of leaf length to width, specific leaf area (SLA), and leaf dry mass based on eight stands growing at different latitudes in the coastal area of eastern China, as well as their relationships with climatic and soil factors. The results showed that the leaf length, leaf width and leaf perimeter increased with increasing latitude, while the leaf area and SLA firstly increased and then decreased. The mean annual temperature and annual precipitation were the major environmental factors affecting the leaf traits along latitude gradient. With the increase of soil N content, the SLA decreased firstly and then increased, while the leaf mass decreased significantly. With the increase of soil P content, the SLA increased, and the leaf mass decreased significantly.

  2. Interaction between Silver Nanoparticles and Spinach Leaf

    Science.gov (United States)

    Tian, Y.; Li, H.; Zhang, Y.; Riser, E.; He, S.; Zhang, W.

    2013-12-01

    Interactions of engineered nanoparticles (ENPs) with plant surfaces are critical to assessing the bioavailability of ENPs to edible plants and to further evaluating impacts of ENPs on ecological health and food safety. Silver nanoparticles (i.e., nanoAg) could enter the agroecosystems either as an active ingredient in pesticides or from other industrial and consumer applications. Thus, in the events of pesticide application, rainfall, and irrigation, vegetable leaves could become in contact and then interact with nanoAg. The present study was to assess whether the interaction of nanoAg with spinach leaves can be described by classical sorption models and to what extent it depends on and varies with dispersion methods, environmental temperature, and ion release. We investigated the stability and ion release of nanoAg dispersed by sodium dodecyl sulfate (SDS, 1%) and humic acid (HA, 10 mg C/L) solutions, as well as sorption and desorption of nanoAg on and from the fresh spinach leaf. Results showed SDS-nanoAg released about 2%-8% more Ag ion than HA-nanoAg. The sorption of Ag ion, described by the Freundlich model in the initial concentration range of 0.6-50 mg/L, was 2-4 times higher than that of nanoAg. The sorption of nanoAg on spinach leaf can be fitted by the Langmuir model, and the maximum sorption amount of HA-nanoAg and SDS-nanoAg was 0.21 and 0.41 mg/g, respectively. The higher sorption of SDS-nanoAg relative to that of HA-nanoAg could be partially resulted from the higher release of Ag ion from the former. The maximum desorption amount of HA-nanoAg and SDS-nanoAg in 1% SDS solution was 0.08 and 0.10 mg/g, respectively. NanoAg attachment on and its penetration to the spinach leaf was visualized by the Scanning Electron Microscope equipped with an Energy Dispersive Spectrometer (SEM-EDS). It is equally important that the less sorption of nanoAg under low environmental temperature could be partially due to the closure of stomata, as verified by SEM-EDS. Cyto

  3. Using Leaf Samples to Establish a Library of Tropical Leaf Fingerprints

    Science.gov (United States)

    Ngo, P.; Nguyen, R.; Anderson, C.; Weiss, P.

    2010-12-01

    Variation in leaf chemistry is directly expressed in spectroscopic patterns of tropical canopies. The goal of the Spectranomics project is to explore this variation in the hopes of developing a method to measure tropical forest diversity remotely from airborne or space-bound spectroscopy in the future. We analyzed tomato leaves for various chemical compositions to better understand the Spectranomics approach to quantifying chemical data of tropical species. We also compared our data to standard data in each analysis. Our results allow us to give the tomato leaves a chemical signature in which we are able to use to compare to other leaf samples. Using this process, we are able to create a library of leaf signatures and document the variety of tree species in tropical forests around the world.

  4. Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

    International Nuclear Information System (INIS)

    Bailey, Brian N; Mahaffee, Walter F

    2017-01-01

    The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometry of real domains at this scale given available measurements. An emerging technology in this field has been the use of terrestrial LiDAR scanning data to rapidly measure the three-dimensional geometry of trees, such as the distribution of leaf area. However, current LiDAR methods suffer from the limitation that they require detailed knowledge of leaf orientation in order to translate projected leaf area into actual leaf area. Common methods for measuring leaf orientation are often tedious or inaccurate, which places constraints on the LiDAR measurement technique. This work presents a new method to simultaneously measure leaf orientation and leaf area within an arbitrarily defined volume using terrestrial LiDAR data. The novelty of the method lies in the direct measurement of the fraction of projected leaf area G from the LiDAR data which is required to relate projected leaf area to total leaf area, and in the new way in which radiation transfer theory is used to calculate leaf area from the LiDAR data. The method was validated by comparing LiDAR-measured leaf area to (1) ‘synthetic’ or computer-generated LiDAR data where the exact area was known, and (2) direct measurements of leaf area in the field using destructive sampling. Overall, agreement between the LiDAR and reference measurements was very good, showing a normalized root-mean-squared-error of about 15% for the synthetic tests, and 13% in the field. (paper)

  5. Method for continuous measurement of export from a leaf

    International Nuclear Information System (INIS)

    Geiger, D.R.; Fondy, B.R.

    1979-01-01

    Export of labeled material derived by continuous photosynthesis in 14 CO 2 was monitored with a Geiger-Mueller detector positioned next to an exporting leaf blade. Rate of export of labeled material was calculated from the difference between rates of retention and net photosynthesis of labeled carbon for the observed leaf. Given certain conditions, including nearly constant distribution of labeled material among minor veins and various types of cells, count rate data for the source leaf can be coverted to rate of export of carbon. Changes in counting efficiency resulting from changes in leaf water status can be corrected for with data from a transducer which measures leaf thickness. Export data agreed with data obtained by monitoring the arrival of 14 C in the sink region; isolated leaves gave values near zero for export of labeled carbon from a given leaf on an intact plant. The technique detects changes in export with a resolution of 10 to 20 minutes

  6. Endophytic fungi reduce leaf-cutting ant damage to seedlings

    Science.gov (United States)

    Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

    2011-01-01

    Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

  7. Leaf surface anatomy in some woody plants from northeastern Mexico

    International Nuclear Information System (INIS)

    Maiti, R.; Rodriguez, H.G.; Balboa, P.C.R.; Kumari, A

    2016-01-01

    Studies on leaf surface anatomy of woody plants and its significance are rare. The present study was undertaken in the Forest Science Faculty Experimental Research Station, UANL, Mexico, with objectives to determine the variability in leaf surface anatomy in the woody plants of the Tamaulipan thornscrub and its utility in taxonomy and possible adaptation to the prevailing semiarid conditions. The results show the presence of large variability in several leaf anatomical traits viz., waxy leaf surface, type of stomata, its size, and distribution. The species have been classified on the basis of various traits which can be used in species delimitation and adaptation to the semiarid condition such as waxy leaf surface, absence sparse stomata on the leaf surface, sunken stomata. The species identified as better adapters to semi-arid environments on the basis of the presence and absence of stomata on both adaxial and abaxial surface viz., Eysenhardtia texana, Parkinsonia texana, Gymnosperma glutinosum, Celtis laevigata, Condalia hookeri and Karwinskia humboldtiana. (author)

  8. GOLD IS EARNED FROM THE PRODUCTION OF THAI GOLD LEAF

    Directory of Open Access Journals (Sweden)

    Dirk Bax

    2010-06-01

    Full Text Available Thai people like to cover sacred objects or things dear to them with gold leaf.. Statues of Buddha are sometimes covered with so many layers of gold leaf that they become formless figures, that can hardly be recognized. Portraits of beloved ancestors, statues of elephants and grave tombs are often covered with gold leaf. If one considers the number of Thai people and the popularity of the habit, the amount of gold involved could be considerable.

  9. Generality of leaf trait relationships: A test across six biomes

    Energy Technology Data Exchange (ETDEWEB)

    Reich, P.B. [Univ. of Minnesota, Saint Paul, MN (United States). Dept. of Forest Resources; Ellsworth, D.S. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Walters, M.B. [Michigan State Univ., East Lansing, MI (United States). Dept. of Forestry; Vose, J.M. [Forest Service, Otto, NC (United States). Coweeta Hydrological Lab.; Gresham, C. [Clemson Univ., Georgetown, SC (United States). Baruch Forest Inst.; Volin, J.C. [Florida Atlantic Univ., Davie, FL (United States). Div. of Science; Bowman, W.D. [Inst. of Arctic and Alpine Research, Boulder, CO (United States). Mountain Research Station]|[Univ. of Colorado, Boulder, CO (United States). Dept. of Evolutionary, Population, and Organismic Biology

    1999-09-01

    Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here the authors address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A{sub max}), leaf diffusive conductance (G{sub S}), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N{sub mass}), SLA, G{sub S}, and A{sub max} were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships among key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A{sub max} for a given level of G{sub S} and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A{sub max}, N, and SLA) while a second axis reflected climate, G{sub S}, and other area-based leaf traits.

  10. Leaf size indices and structure of the peat swamp forest

    Directory of Open Access Journals (Sweden)

    L.G. Aribal

    2017-12-01

    Full Text Available Leaf size indices of the tree species in the peatland of Agusan del Sur in Mindanao in Philippines was examined to deduce the variation of forest structure and observed forest zonation.  Using raunkiaer and webb’s leaf size classification, the leaf morphometrics of seven tree species consistently found on the established sampling plots were determined.  The species includes Ternstroemia philippinensis Merr., Polyscias aherniana Merr. Lowry and G.M. Plunkett, Calophyllum sclerophyllum Vesque, Fagraea racemosa Jack, Ilex cymosa Blume, Syzygium tenuirame (Miq. Merr. and Tristaniopsis micrantha Merr. Peter G.Wilson and J.T.Waterh.The LSI were correlated against the variables of the peat physico-chemical properties (such as bulk density, acrotelm thickness, peat depth, total organic carbon, nitrogen, phosphorus, and potassium, pH; water (pH, ammonium, nitrate, phosphate; and leaf tissue elements (nitrogen, phosphorus and potassium.  Result showed a decreasing leaf size indices and a three leaf size category consisting of mesophyllous, mesophyllous-notophyllous and microphyllous were observed which corresponds to the structure of vegetation i.e., from the tall-pole forest having the biggest average leaf area of 6,142.29 mm2 to the pygmy forest with average leaf area of 1,670.10 mm2.  Such decreased leaf size indices were strongly correlated to soil nitrogen, acrotelm thickness, peat depth, phosphate in water, nitrogen and phosphorus in the plant tissue.

  11. Silver nano fabrication using leaf disc of Passiflora foetida Linn

    Science.gov (United States)

    Lade, Bipin D.; Patil, Anita S.

    2017-06-01

    The main purpose of the experiment is to develop a greener low cost SNP fabrication steps using factories of secondary metabolites from Passiflora leaf extract. Here, the leaf extraction process is omitted, and instead a leaf disc was used for stable SNP fabricated by optimizing parameters such as a circular leaf disc of 2 cm (1, 2, 3, 4, 5) instead of leaf extract and grade of pH (7, 8, 9, 11). The SNP synthesis reaction is tried under room temperature, sun, UV and dark condition. The leaf disc preparation steps are also discussed in details. The SNP obtained using (1 mM: 100 ml AgNO3+ singular leaf disc: pH 9, 11) is applied against featured room temperature and sun condition. The UV spectroscopic analysis confirms that sun rays synthesized SNP yields stable nano particles. The FTIR analysis confirms a large number of functional groups such as alkanes, alkyne, amines, aliphatic amine, carboxylic acid; nitro-compound, alcohol, saturated aldehyde and phenols involved in reduction of silver salt to zero valent ions. The leaf disc mediated synthesis of silver nanoparticles, minimizes leaf extract preparation step and eligible for stable SNP synthesis. The methods sun and room temperature based nano particles synthesized within 10 min would be use certainly for antimicrobial activity.

  12. Inheritance of okra leaf type in different genetic backgrounds and its ...

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... discontinuous variation for leaf shape in F2 generations of three crosses .... Variable classes in leaf types (a) Normal leaf (b) Okra leaf (c) Sub-okra leaf. ..... insect pests on different isogenic lines of cotton variety H-777. J.

  13. Side Effects of Fungicides Used in Cucurbitaceous Crop on Trichogrammaatopovirilia Oatman & Platner (Hymenoptera: Trichogramatidae Efectos Secundarios sobre Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogramatidae de Fungicidas usados en Cucurbitáceas

    Directory of Open Access Journals (Sweden)

    Dirceu Pratissoli

    2010-06-01

    producción de cucurbitáceas en Trichogramma atopovirilia Oatman & Platner sobre huevos de D. hyalinata. Se evaluaron los fungicidas azoxystrobina (0.08 g ingrediente activo [ia] L-1, clorotalonil (2.00 g ia L-1, mancozeb (1.60 g ia L-1, tebuconazole (0.25 g ia L-1 and tiofanato-metil (0.49 g ia L-1. Tarjetas con 30 huevos de D. hyalinata previamente sumergidos en los fungicidas y en agua destilada (control fueron ofrecidas a 20 hembras de T. atopovirilia con hasta 24 h de emergencia individualizadas en tubos de vidrio. Se evaluó parasitismo, reducción de parasitismo, emergencia, proporción sexual en la población y el número de individuos emergidos por huevo. Los fungicidas clorotalonil, tiofanato-metil y tebuconazol redujeron el parasitismo de T. atopovirilia en 43,37; 27,64 y 18,51%, respectivamente. Sin embargo, el parasitismo con azoxistrobina (79,21% fue mayor que el control (67,37% (P ≤ 0,05. Clorotalonil, tiofanato-metilo y el tebuconazol redujo la aparición de 73,77, 75,62 y 79,35% (P ≤ 0,05, respectivamente. Azoxistrobina y tiofanato-metil reduciran la proporción de sexos de 0,77 y 0,76 (P ≤ 0,05, respectivamente. Ninguno de los fungicidas redujo el número de individuos por cada huevo. Los fungicidas azoxistrobina y mancozeb fueron selectivos para T. atopovirilia en la mayoría de los parámetros estudiados, por lo tanto, deberían tener prioridad en el manejo de enfermedades de cucurbitáceas para permitir el uso eficiente de los enemigos naturales de D. hyalinata.

  14. Allelopathic potential of Rapanea umbellata leaf extracts.

    Science.gov (United States)

    Novaes, Paula; Imatomi, Maristela; Varela, Rosa M; Molinillo, José M G; Lacret, Rodney; Gualtieri, Sonia C J; Macías, Francisco A

    2013-08-01

    The stressful conditions associated with the Brazilian savanna (Cerrado) environment were supposed to favor higher levels of allelochemicals in Rapanea umbellata from this ecosystem. The allelopathic potential of R. umbellata leaf extracts was studied using the etiolated wheat coleoptile and standard phytotoxicity bioassays. The most active extract was selected to perform a bioassay-guided isolation, which allowed identifying lutein (1) and (-)-catechin (2) as potential allelochemicals. Finally, the general bioactivity of the two compounds was studied, which indicated that the presence of 1 might be part of the defense mechanisms of this plant. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Leaf nutrient resorption, leaf lifespan and the retention of nutrients in seagrass systems

    NARCIS (Netherlands)

    Hemminga, M.A.; Marbà, N.; Stapel, J.

    1999-01-01

    Efficient nutrient resorption from senescing leaves, and extended leaf life spans are important strategies in order to conserve nutrients for plants in general. Despite the fact that seagrasses often grow in oligotrophic waters, these conservation strategies are not strongly developed in seagrasses.

  16. Accumulation of three different sizes of particulate matter on plant leaf surfaces: Effect on leaf traits

    Directory of Open Access Journals (Sweden)

    Chen Xiaoping

    2015-01-01

    Full Text Available Plants not only improve air quality by adsorbing particulate matter (PM on leaf surfaces but can also be affected by their accumulation. In this study, a field investigation was performed in Wuhan, China, into the relationship between seven leaf traits and the accumulation of three different sizes of PM (PM11, PM2.5 and PM0.2 on leaves. The retention abilities of plant leaves with respect to the three sizes of PM differed significantly at different sites and species. The average PM retention capabilities of plant leaves and specific leaf area (SLA were significantly greater in a seriously polluted area, whereas the average values of chlorophyll a (Chl a, chlorophyll b (Chl b, total chlorophyll, carotenoid, pH and relative water content (RWC were greater at the control site. SLA significantly positively correlated with the size of PM, but Chl a, Chl b, total chlorophyll, RWC significantly negatively correlated with the size of PM, whereas the pH did not correlate significantly with the the PM fractions. Additionally, SLA was found to be affected by large particles (PM11, p<0.01; PM2.5 had a more obvious effect on plant leaf traits than the other PM (p<0.05. Overall, the findings from this study provide useful information regarding the selection of plants to reduce atmospheric pollution.

  17. Automated Leaf Tracking using Multi-view Image Sequences of Maize Plants for Leaf-growth Monitoring

    Science.gov (United States)

    Das Choudhury, S.; Awada, T.; Samal, A.; Stoerger, V.; Bashyam, S.

    2017-12-01

    Extraction of phenotypes with botanical importance by analyzing plant image sequences has the desirable advantages of non-destructive temporal phenotypic measurements of a large number of plants with little or no manual intervention in a relatively short period of time. The health of a plant is best interpreted by the emergence timing and temporal growth of individual leaves. For automated leaf growth monitoring, it is essential to track each leaf throughout the life cycle of the plant. Plants are constantly changing organisms with increasing complexity in architecture due to variations in self-occlusions and phyllotaxy, i.e., arrangements of leaves around the stem. The leaf cross-overs pose challenges to accurately track each leaf using single view image sequence. Thus, we introduce a novel automated leaf tracking algorithm using a graph theoretic approach by multi-view image sequence analysis based on the determination of leaf-tips and leaf-junctions in the 3D space. The basis of the leaf tracking algorithm is: the leaves emerge using bottom-up approach in the case of a maize plant, and the direction of leaf emergence strictly alternates in terms of direction. The algorithm involves labeling of the individual parts of a plant, i.e., leaves and stem, following graphical representation of the plant skeleton, i.e., one-pixel wide connected line obtained from the binary image. The length of the leaf is measured by the number of pixels in the leaf skeleton. To evaluate the performance of the algorithm, a benchmark dataset is indispensable. Thus, we publicly release University of Nebraska-Lincoln Component Plant Phenotyping dataset-2 (UNL-CPPD-2) consisting of images of the 20 maize plants captured by visible light camera of the Lemnatec Scanalyzer 3D high throughout plant phenotyping facility once daily for 60 days from 10 different views. The dataset is aimed to facilitate the development and evaluation of leaf tracking algorithms and their uniform comparisons.

  18. On the temporal variation of leaf magnetic parameters: seasonal accumulation of leaf-deposited and leaf-encapsulated particles of a roadside tree crown.

    Science.gov (United States)

    Hofman, Jelle; Wuyts, Karen; Van Wittenberghe, Shari; Samson, Roeland

    2014-09-15

    Understanding the accumulation behaviour of atmospheric particles inside tree leaves is of great importance for the interpretation of biomagnetic monitoring results. In this study, we evaluated the temporal variation of the saturation isothermal remanent magnetisation (SIRM) of leaves of a roadside urban Platanus × acerifolia Willd. tree in Antwerp, Belgium. We hereby examined the seasonal development of the total leaf SIRM signal as well as the leaf-encapsulated fraction of the deposited dust, by washing the leaves before biomagnetic analysis. On average 38% of the leaf SIRM signal was exhibited by the leaf-encapsulated particles. Significant correlations were found between the SIRM and the cumulative daily average atmospheric PM10 and PM2.5 measurements. Moreover, a steady increase of the SIRM throughout the in-leaf season was observed endorsing the applicability of biomagnetic monitoring as a proxy for the time-integrated PM exposure of urban tree leaves. Strongest correlations were obtained for the SIRM of the leaf-encapsulated particles which confirms the dynamic nature of the leaf surface-accumulated particles. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Estimating leaf photosynthetic pigments information by stepwise multiple linear regression analysis and a leaf optical model

    Science.gov (United States)

    Liu, Pudong; Shi, Runhe; Wang, Hong; Bai, Kaixu; Gao, Wei

    2014-10-01

    Leaf pigments are key elements for plant photosynthesis and growth. Traditional manual sampling of these pigments is labor-intensive and costly, which also has the difficulty in capturing their temporal and spatial characteristics. The aim of this work is to estimate photosynthetic pigments at large scale by remote sensing. For this purpose, inverse model were proposed with the aid of stepwise multiple linear regression (SMLR) analysis. Furthermore, a leaf radiative transfer model (i.e. PROSPECT model) was employed to simulate the leaf reflectance where wavelength varies from 400 to 780 nm at 1 nm interval, and then these values were treated as the data from remote sensing observations. Meanwhile, simulated chlorophyll concentration (Cab), carotenoid concentration (Car) and their ratio (Cab/Car) were taken as target to build the regression model respectively. In this study, a total of 4000 samples were simulated via PROSPECT with different Cab, Car and leaf mesophyll structures as 70% of these samples were applied for training while the last 30% for model validation. Reflectance (r) and its mathematic transformations (1/r and log (1/r)) were all employed to build regression model respectively. Results showed fair agreements between pigments and simulated reflectance with all adjusted coefficients of determination (R2) larger than 0.8 as 6 wavebands were selected to build the SMLR model. The largest value of R2 for Cab, Car and Cab/Car are 0.8845, 0.876 and 0.8765, respectively. Meanwhile, mathematic transformations of reflectance showed little influence on regression accuracy. We concluded that it was feasible to estimate the chlorophyll and carotenoids and their ratio based on statistical model with leaf reflectance data.

  20. Leaf turgor loss point is correlated with drought tolerance and leaf carbon economics traits.

    Science.gov (United States)

    Zhu, Shi-Dan; Chen, Ya-Jun; Ye, Qing; He, Peng-Cheng; Liu, Hui; Li, Rong-Hua; Fu, Pei-Li; Jiang, Guo-Feng; Cao, Kun-Fang

    2018-05-01

    Leaf turgor loss point (πtlp) indicates the capacity of a plant to maintain cell turgor pressure during dehydration, which has been proven to be strongly predictive of the plant response to drought. In this study, we compiled a data set of πtlp for 1752 woody plant individuals belonging to 389 species from nine major woody biomes in China, along with reduced sample size of hydraulic and leaf carbon economics data. We aimed to investigate the variation of πtlp across biomes varying in water availability. We also tested two hypotheses: (i) πtlp predicts leaf hydraulic safety margins and (ii) it is correlated with leaf carbon economics traits. Our results showed that there was a positive relationship between πtlp and aridity index: biomes from humid regions had less negative values than those from arid regions. This supports the idea that πtlp may reflect drought tolerance at the scale of woody biomes. As expected, πtlp was significantly positively correlated with leaf hydraulic safety margins that varied significantly across biomes, indicating that this trait may be useful in modelling changes of forest components in response to increasing drought. Moreover, πtlp was correlated with a suite of coordinated hydraulic and economics traits; therefore, it can be used to predict the position of a given species along the 'fast-slow' whole-plant economics spectrum. This study expands our understanding of the biological significance of πtlp not only in drought tolerance, but also in the plant economics spectrum.

  1. BREEAM Green Leaf Eco-rating Program

    International Nuclear Information System (INIS)

    2001-01-01

    The environmental performance of buildings is measured for several reasons, the main one being that it can help owners decide where to invest their retrofit dollars to maximize the energy performance of their building and reduce operating costs. The buildings constructed in the 1950s and 1960s in North America are reaching obsolescence and will require major retrofits to improve their energy efficiency, particularly in the area of mechanical equipment. In addition to reducing operating costs, better maintenance and environmental management of buildings can also address issues such as comfort, health, indoor air quality and productivity. In order to accurately measure the environmental performance of a building, it is necessary to develop a comprehensive measuring and benchmarking tool that would allow occupants to compare the buildings' performance with others. In this pilot study, 6 high-rise multi-residential buildings were assessed for environmental performance using the BREEAM Green Leaf assessment method. The methodology originated in Canada and was developed by ECD Energy, Environment Canada and Terra Choice. It combines the BREEAM set of environmental issues with the Green Leaf Eco-Rating technique. The method covers occupant health, energy efficiency, resource efficiency, environmental responsibility and affordability. Operation and management issues are also taken into consideration. The buildings used in this study were located in various locations, ranging from inner city housing to city/suburban areas. 2 tabs., 17 figs

  2. Sorption of lead from aqueous solutions by spent tea leaf | Yoshita ...

    African Journals Online (AJOL)

    Pb) from solution. The Pb removal by the spent tea leaf adsorbent depended on pretreatment of spent tea leaf, adsorption contact time and adsorbent dosage. The optimum pretreatment conditions were confirmed to be that tea leaf was ground ...

  3. The dosimetric impact of leaf interdigitation and leaf width on VMAT treatment planning in Pinnacle: comparing Pareto fronts

    International Nuclear Information System (INIS)

    Van Kesteren, Z; Janssen, T M; Damen, E; Van Vliet-Vroegindeweij, C

    2012-01-01

    To evaluate in an objective way the effect of leaf interdigitation and leaf width on volumetric modulated arc therapy plans in Pinnacle. Three multileaf collimators (MLCs) were modeled: two 10 mm leaf width MLCs, with and without interdigitating leafs, and a 5 mm leaf width MLC with interdigitating leafs. Three rectum patients and three prostate patients were used for the planning study. In order to compare treatment techniques in an objective way, a Pareto front comparison was carried out. 200 plans were generated in an automated way, per patient per MLC model, resulting in a total of 3600 plans. From these plans, Pareto-optimal plans were selected which were evaluated for various dosimetric variables. The capability of leaf interdigitation showed little dosimetric impact on the treatment plans, when comparing the 10 mm leaf width MLC with and without leaf interdigitation. When comparing the 10 mm leaf width MLC with the 5 mm leaf width MLC, both with interdigitating leafs, improvement in plan quality was observed. For both patient groups, the integral dose was reduced by 0.6 J for the thin MLC. For the prostate patients, the mean dose to the anal sphincter was reduced by 1.8 Gy and the conformity of the V 95% was reduced by 0.02 using the thin MLC. The V 65% of the rectum was reduced by 0.1% and the dose homogeneity with 1.5%. For rectum patients, the mean dose to the bowel was reduced by 1.4 Gy and the mean dose to the bladder with 0.8 Gy for the thin MLC. The conformity of the V 95% was equivalent for the 10 and 5 mm leaf width MLCs for the rectum patients. We have objectively compared three types of MLCs in a planning study for prostate and rectum patients by analyzing Pareto-optimal plans which were generated in an automated way. Interdigitation of MLC leafs does not generate better plans using the SmartArc algorithm in Pinnacle. Changing the MLC leaf width from 10 to 5 mm generates better treatment plans although the clinical relevance remains to be proven

  4. The dosimetric impact of leaf interdigitation and leaf width on VMAT treatment planning in Pinnacle: comparing Pareto fronts.

    Science.gov (United States)

    van Kesteren, Z; Janssen, T M; Damen, E; van Vliet-Vroegindeweij, C

    2012-05-21

    To evaluate in an objective way the effect of leaf interdigitation and leaf width on volumetric modulated arc therapy plans in Pinnacle. Three multileaf collimators (MLCs) were modeled: two 10 mm leaf width MLCs, with and without interdigitating leafs, and a 5 mm leaf width MLC with interdigitating leafs. Three rectum patients and three prostate patients were used for the planning study. In order to compare treatment techniques in an objective way, a Pareto front comparison was carried out. 200 plans were generated in an automated way, per patient per MLC model, resulting in a total of 3600 plans. From these plans, Pareto-optimal plans were selected which were evaluated for various dosimetric variables. The capability of leaf interdigitation showed little dosimetric impact on the treatment plans, when comparing the 10 mm leaf width MLC with and without leaf interdigitation. When comparing the 10 mm leaf width MLC with the 5 mm leaf width MLC, both with interdigitating leafs, improvement in plan quality was observed. For both patient groups, the integral dose was reduced by 0.6 J for the thin MLC. For the prostate patients, the mean dose to the anal sphincter was reduced by 1.8 Gy and the conformity of the V(95%) was reduced by 0.02 using the thin MLC. The V(65%) of the rectum was reduced by 0.1% and the dose homogeneity with 1.5%. For rectum patients, the mean dose to the bowel was reduced by 1.4 Gy and the mean dose to the bladder with 0.8 Gy for the thin MLC. The conformity of the V(95%) was equivalent for the 10 and 5 mm leaf width MLCs for the rectum patients. We have objectively compared three types of MLCs in a planning study for prostate and rectum patients by analyzing Pareto-optimal plans which were generated in an automated way. Interdigitation of MLC leafs does not generate better plans using the SmartArc algorithm in Pinnacle. Changing the MLC leaf width from 10 to 5 mm generates better treatment plans although the clinical relevance remains

  5. Biophysical constraints on leaf expansion in a tall conifer.

    Science.gov (United States)

    Fredrick C. Meinzer; Barbara J. Bond; Jennifer A. Karanian

    2008-01-01

    The physiological mechanisms responsible for reduced extension growth as trees increase in height remain elusive. We evaluated biophysical constraints on leaf expansion in old-growth Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) trees. Needle elongation rates, plastic and elastic extensibility, bulk leaf water, (L...

  6. Cassava brown streak disease effects on leaf metabolites and ...

    African Journals Online (AJOL)

    Cassava brown streak disease effects on leaf metabolites and pigment accumulation. ... Total reducing sugar and starch content also dropped significantly (-30 and -60%, respectively), much as NASE 14 maintained a relatively higher amount of carbohydrates. Leaf protein levels were significantly reduced at a rate of 0.07 ...

  7. Ozone exposure affects leaf wettability and tree water balance

    NARCIS (Netherlands)

    Schreuder, M.D.J.; Hove, van L.W.A.; Brewer, C.A.

    2001-01-01

    Relatively little is known about the influences of growing-season background ozone (O3) concentrations on leaf cuticles and foliar water loss. Using fumigation chambers, leaf wettability and foliar water loss were studied in two poplar species, Populus nigra and P. euramericana, and a conifer,

  8. Suppressors of RNA silencing encoded by tomato leaf curl

    Indian Academy of Sciences (India)

    Whitefly-transmitted begomoviruses infecting tomato crop code for five different proteins, ORF AC4, ORF AC2 and ORF AV2 in DNA-A component, ORF BV1 in DNA-B ... In the present study suppressor function of ORF C1 of three betasatellites Tomato leaf curl Bangalore betasatellite ToLCBB-[IN:Hess:08], Cotton leaf curl ...

  9. Ontogeny of the sheathing leaf base in maize (Zea mays).

    Science.gov (United States)

    Johnston, Robyn; Leiboff, Samuel; Scanlon, Michael J

    2015-01-01

    Leaves develop from the shoot apical meristem (SAM) via recruitment of leaf founder cells. Unlike eudicots, most monocot leaves display parallel venation and sheathing bases wherein the margins overlap the stem. Here we utilized computed tomography (CT) imaging, localization of PIN-FORMED1 (PIN1) auxin transport proteins, and in situ hybridization of leaf developmental transcripts to analyze the ontogeny of monocot leaf morphology in maize (Zea mays). CT imaging of whole-mounted shoot apices illustrates the plastochron-specific stages during initiation of the basal sheath margins from the tubular disc of insertion (DOI). PIN1 localizations identify basipetal auxin transport in the SAM L1 layer at the site of leaf initiation, a process that continues reiteratively during later recruitment of lateral leaf domains. Refinement of these auxin transport domains results in multiple, parallel provascular strands within the initiating primordium. By contrast, auxin is transported from the L2 toward the L1 at the developing margins of the leaf sheath. Transcripts involved in organ boundary formation and dorsiventral patterning accumulate within the DOI, preceding the outgrowth of the overlapping margins of the sheathing leaf base. We suggest a model wherein sheathing bases and parallel veins are both patterned via the extended recruitment of lateral maize leaf domains from the SAM. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  10. Timing and duration of autumn leaf development in Sweden

    Science.gov (United States)

    Bolmgren, Kjell

    2014-05-01

    The growing season is changing in both ends and autumn phases seem to be responding in more diverse ways than spring events. Indeed, we know little about autumn leaf phenological strategies and how they are correlated with fitness components or ecosystem properties, and how they vary between species and over bioclimatic gradients. In this study more than 10 000 students were involved in observing autumn leaf development at 378 sites all over Sweden (55-68°N). They followed an image based observation protocol classifying autumn leaf development into five levels, from summer green (level 0) to 100% autumn leaf colored (level 4) canopy. In total, they submitted almost 12 000 observations between August 9 and November 15. 75% of the observations were made on the common species of Populus tremula, Betula pendula/pubescens and Sorbus aucuparia. The expected (negative) correlation between latitude and start of leaf senescence (level 2) was found in Populus and Betula, but not in Sorbus. The duration of the leaf senescence period, defined as the period between 1/3 (level 2) and 100% (level 4) of the canopy autumn leaf colored, was negatively correlated with latitude in Populus and Betula, but not in Sorbus. There was also a strong (negative) correlation of the start (level 2) and the duration of the leaf senescence in the early senescing Sorbus and Betula, while this effect was weaker in the late senescing Populus.

  11. 7 CFR 29.2662 - Heavy Leaf (B Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Heavy Leaf (B Group). 29.2662 Section 29.2662 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2662 Heavy Leaf (B Group). This group consists of leaves...

  12. 7 CFR 29.2438 - Thin Leaf (C Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Thin Leaf (C Group). 29.2438 Section 29.2438... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2438 Thin Leaf (C Group). This group consists of leaves... body than those of the B group, and show little or no ground injury. Choice- and fine-quality tobacco...

  13. 7 CFR 29.2437 - Heavy Leaf (B Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Heavy Leaf (B Group). 29.2437 Section 29.2437... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2437 Heavy Leaf (B Group). This group consists of leaves..., are heavier in body than those of the X or C groups, and show no ground injury. Choice- and fine...

  14. 7 CFR 29.1163 - Smoking Leaf (H Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Smoking Leaf (H Group). 29.1163 Section 29.1163... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.1163 Smoking Leaf (H Group). This group consists of leaves normally grown at or above the midportion of the stalk. Leaves of the H group show a high degree...

  15. 7 CFR 29.1162 - Leaf (B Group).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf (B Group). 29.1162 Section 29.1162 Agriculture... INSPECTION Standards Grades § 29.1162 Leaf (B Group). This group consists of leaves normally grown at or above the midportion of the stalk. Leaves of the B group have a pointed tip, tend to fold, usually are...

  16. Evaluation of Microdesmis puberula leaf meal as feed ingredient in ...

    African Journals Online (AJOL)

    The material was milled using a hammer mill to produce the leaf meal. Microdesmis puberula leaf meal contain 17.32% crude protein, 6.52% ether extract, 12.25% total ash, 24.84% crude fibre, 24.06% NFE and an appreciable percent of minerals. Three broiler starter diets were formulated to contain the meal at dietary ...

  17. Antimalarial Anthrone and Chromone from the Leaf Latex of Aloe ...

    African Journals Online (AJOL)

    In Ethiopian traditional medicine, the leaf latex of Aloe debranan Chrstian is used for the treatment of several diseases including malaria. In an ongoing search for effective, safe and cheap antimalarial agents from plants, the leaf latex of A. debrana was tested for its in vivo antimalarial activity, in a 4-day suppressive assay ...

  18. The effect of quince leaf ( Cydonia oblonga miller) decoction on ...

    African Journals Online (AJOL)

    Current medical literature lacks any evidence of the protective effects of quince leaf on testes. Therefore, the aim of the present study was to assess the effect of quince (Cydonia oblonga Miller) leaf decoction on testicular injury and impaired spermatogenesis induced by hypercholesterolemia in rabbits. Eleven mature New ...

  19. Leaf gas exchange of mature bottomland oak trees

    Science.gov (United States)

    Rico M. Gazal; Mark E. Kubiske; Kristina F. Connor

    2009-01-01

    We determined how changes in environmental moisture affected leaf gas exchange in Nuttall (Quercus texana Buckley), overcup (Q. lyrata Walt.), and dominant and codominant swamp chestnut (Q. michauxii Nutt.) oak trees in Mississippi and Louisiana. We used canopy access towers to measure leaf level gas...

  20. Modeling the leaf angle dynamics in rice plant.

    Directory of Open Access Journals (Sweden)

    Yonghui Zhang

    Full Text Available The leaf angle between stem and sheath (SSA is an important rice morphological trait. The objective of this study was to develop and validate a dynamic SSA model under different nitrogen (N rates for selected rice cultivars. The time-course data of SSA were collected in three years, and a dynamic SSA model was developed for different main stem leaf ranks under different N rates for two selected rice cultivars. SSA increased with tiller age. The SSA of the same leaf rank increased with increase in N rate. The maximum SSA increased with leaf rank from the first to the third leaf, then decreased from the third to the final leaf. The relationship between the maximum SSA and leaf rank on main stem could be described with a linear piecewise function. The change of SSA with thermal time (TT was described by a logistic equation. A variety parameter (the maximum SSA of the 3rd leaf on main stem and a nitrogen factor were introduced to quantify the effect of cultivar and N rate on SSA. The model was validated against data collected from both pot and field experiments. The relative root mean square error (RRMSE was 11.56% and 14.05%, respectively. The resulting models could be used for virtual rice plant modeling and plant-type design.

  1. Value of Bitter Leaf ( Vernonia amygdalina ) Meal as Feed ...

    African Journals Online (AJOL)

    A 28-day feeding trial was conducted to evaluate the effect of bitter leaf (Vernonia amygdalina) leaf meal as feed ingredient on the performance, feed cost and carcass and organ weights of finisher broilers. The leaves were air dried under room temperature, ground and sieved through a 3 mm mesh to produce the meal.

  2. ( Azadirachta Indica ) Leaf Extracts on the Rot Fungus ( Fusarium ...

    African Journals Online (AJOL)

    The storage lifespan of kola nuts is challenged by the problem of decay of nuts in storage as a result of the attack by the rot fungus (Fusarium spp). The effect of the neem leaf (Azadirachta indica) extracts on the rot fungus was investigated in order to aid extended kola nuts storage. The aqueous and ethanolic leaf extracts of ...

  3. Predicting tropical plant physiology from leaf and canopy spectroscopy.

    Science.gov (United States)

    Doughty, Christopher E; Asner, Gregory P; Martin, Roberta E

    2011-02-01

    A broad regional understanding of tropical forest leaf photosynthesis has long been a goal for tropical forest ecologists, but it has remained elusive due to difficult canopy access and high species diversity. Here we develop an empirical model to predict sunlit, light-saturated, tropical leaf photosynthesis using leaf and simulated canopy spectra. To develop this model, we used partial least squares (PLS) analysis on three tropical forest datasets (159 species), two in Hawaii and one at the biosphere 2 laboratory (B2L). For each species, we measured light-saturated photosynthesis (A), light and CO(2) saturated photosynthesis (A(max)), respiration (R), leaf transmittance and reflectance spectra (400-2,500 nm), leaf nitrogen, chlorophyll a and b, carotenoids, and leaf mass per area (LMA). The model best predicted A [r(2) = 0.74, root mean square error (RMSE) = 2.9 μmol m(-2) s(-1))] followed by R (r(2) = 0.48), and A(max) (r(2) = 0.47). We combined leaf reflectance and transmittance with a canopy radiative transfer model to simulate top-of-canopy reflectance and found that canopy spectra are a better predictor of A (RMSE = 2.5 ± 0.07 μmol m(-2) s(-1)) than are leaf spectra. The results indicate the potential for this technique to be used with high-fidelity imaging spectrometers to remotely sense tropical forest canopy photosynthesis.

  4. Incomplete resistance to coffee leaf rust (Hemileia vastatrix)

    NARCIS (Netherlands)

    Eskes, A.B.

    1983-01-01

    Incomplete resistance to coffee leaf rust ( Hemileia vastatrix ) may be of value in obtaining durable resistance, which is of great importance for the perennial coffee crop. Methods were developed to assess incomplete resistance to coffee leaf rust by using illustrated scales

  5. Composition of the Essential Oil of Clausena Suffruticosa Leaf and ...

    African Journals Online (AJOL)

    Purpose: To investigate the essential oil content of Clausena suffruticosa leaf for its in-vitro antibacterial, antifungal and cytotoxic activities. Methods: The essential oil of Clausena suffruticosa leaf was extracted by hydrodistillation using a modified Clevenger-type apparatus and was analyzed by GC-MS using electron impact ...

  6. Evaluation of Jacaranda mimosifolia T. (Stans) leaf meal as ...

    African Journals Online (AJOL)

    The economic benefit analysis indicated that as the leaf meal increased in the diets the cost of production of the broilers decreased. Jacaranda leaf meal could be best utilized at 5.0% level of inclusion though the 7.5% levels broilers attained market size in a recorded time. Animal Production Research Advances Vol.

  7. Effect of temperature on accumulation of chlorophylls and leaf ...

    African Journals Online (AJOL)

    White young shoots from albino tea cultivars have high level of amino acids and are rare and valuable materials for processing green tea. The effects of temperature on leaf colour, accumulation of chlorophylls and leaf ultrastructures of an albino tea cultivar 'Xiaxueya' were investigated. The study showed that the shoot ...

  8. Comparative antimicrobial activities of aloe vera gel and leaf ...

    African Journals Online (AJOL)

    The comparative antimicrobial activities of the gel and leaf of Aloe vera were tested against Staphylococcus aureus, Pseudomonas aeruginosa, Trichophyton mentagraphytes, T. schoeleinii, Microsporium canis and Candida albicans. Ethanol was used for the extraction of the leaf after obtaining the gel from it. Antimicrobial ...

  9. cassava brown streak disease effects on leaf metabolites

    African Journals Online (AJOL)

    USER

    Plate 1. Progression of CBSD in cassava leaves with scores 1= leaf from clean plant, no CBSD, 2 = Mild CBSD leaf veinal ... absorb the excess water, after which they were rolled ..... to low carbon dioxide exchange, as observed in sugar cane ...

  10. Coconut leaf bioactivity toward generalist maize insect pests

    Science.gov (United States)

    Tropical plants are often more resistant to insects than temperate plants due to evolution of robust defenses to cope with a more constant insect threat. Coconut (Cocos nucifera L.) has very few chewing leaf feeding insect pests and was tested against two omnivorous leaf feeding caterpillar species,...

  11. Somatic embryogenesis and plant regeneration from leaf explants of ...

    African Journals Online (AJOL)

    An attempt was made to study the somatic embryogenesis and plant regeneration from the in vitro leaf explants of Rumex vesicarius L. a renowned medicinal plant, which belongs to polygonaceae family. Effective in vitro regeneration of R. vesicarius was achieved via young leaf derived somatic embryo cultures.

  12. Soil Characteristics, Microbial Compostion of Plot, Leaf Count and ...

    African Journals Online (AJOL)

    Soil Characteristics, Microbial Compostion of Plot, Leaf Count and Sprout Studies of Cocoyam ( Colocasia [Schott] and Xanthosoma [Schott], Araceae) Collected in Edo State, ... Science, Technology and Arts Research Journal ... Government Areas (LGA) in Edo state and describe them based on leaf count and sprout

  13. Phytochemical constituents and ethnobotany of the leaf extract of ...

    African Journals Online (AJOL)

    The phytochemical screening and ethno botanical importance of the leaf of Vernonia amygdalina Del. were investigated. The secondary metabolites in the leaf were identified to establish a relationship between them and their therapeutic properties. The leaves were sun dried, pulverized and sieved. The resulting powdered ...

  14. Effect Of Walnut Leaf, Coriander And Pomegranate On Blood ...

    African Journals Online (AJOL)

    Mechanism of most of herbal used for diabetes mellitus treatment has not been well defined. This study was performed to investigate hypoglycemic effect of walnut leaf (Juglans regia L.), coriander leaf (Coriandrum sativum L.) or pomegranate seed (Punica granatum L.), and their possible role on pancreatic tissue. Diabetes ...

  15. Nutritive evaluation of Telfairia occidentalis leaf protein concentrate ...

    African Journals Online (AJOL)

    Leaf meal (LM), leaf proteins concentrate (LPC) and LPC residues from Telfairia occidentalis were produced, chemically characterized and the protein quality of the LPC evaluated using rats. Five infant weaning foods were formulated using varying combinations of T. occidentalis LPC and soybean meal. These foods were ...

  16. Antimicrobial activity of the aqueous, methanol and chloroform leaf ...

    African Journals Online (AJOL)

    The minimum inhibitory concentration (MIC) of methanol leaf extract show least activity against Yersinia enterocolitica and Pseudomonas aeruginosa (MIC = 100 mg/ml) and higher activity of MIC at 50 mg/ml against the other bacterial test organisms. The chloroform leaf extract MIC of 100 mg/ml had least activity against ...

  17. Do Aphids Alter Leaf Surface Temperature Patterns During Early Infestation?

    Directory of Open Access Journals (Sweden)

    Thomas Cahon

    2018-03-01

    Full Text Available Arthropods at the surface of plants live in particular microclimatic conditions that can differ from atmospheric conditions. The temperature of plant leaves can deviate from air temperature, and leaf temperature influences the eco-physiology of small insects. The activity of insects feeding on leaf tissues, may, however, induce changes in leaf surface temperatures, but this effect was only rarely demonstrated. Using thermography analysis of leaf surfaces under controlled environmental conditions, we quantified the impact of presence of apple green aphids on the temperature distribution of apple leaves during early infestation. Aphids induced a slight change in leaf surface temperature patterns after only three days of infestation, mostly due to the effect of aphids on the maximal temperature that can be found at the leaf surface. Aphids may induce stomatal closure, leading to a lower transpiration rate. This effect was local since aphids modified the configuration of the temperature distribution over leaf surfaces. Aphids were positioned at temperatures near the maximal leaf surface temperatures, thus potentially experiencing the thermal changes. The feedback effect of feeding activity by insects on their host plant can be important and should be quantified to better predict the response of phytophagous insects to environmental changes.

  18. Effects of nitrogen application rate and leaf age on the distribution pattern of leaf SPAD readings in the rice canopy.

    Directory of Open Access Journals (Sweden)

    Hu Yang

    Full Text Available A Soil-Plant Analysis Development (SPAD chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008-2009 using rice plants treated with six different N application levels. N distribution pattern was determined by SPAD readings based on the temporal dynamics of N concentrations in individual leaves. At 62 days after transplantation (DAT in 2008 and DAT 60 in 2009, leaf SPAD readings increased from the upper to lower in the rice canopy that received N levels of 150 to 375 kg ha(-1The differences in SPAD readings between the upper and lower leaf were larger under higher N application rates. However, as plants grew, this atypical distribution of SPAD readings in canopy leaf quickly reversed to the general order. In addition, temporal dynamics of the leaf SPAD readings (N concentrations were fitted to a piecewise function. In our model, changes in leaf SPAD readings were divided into three stages: growth, functioning, and senescence periods. The leaf growth period lasted approximately 6 days, and cumulative growing days were not affected by N application rates. The leaf functioning period was represented with a relatively stable SPAD reading related to N application rate, and cumulative growing days were extended with increasing N application rates. A quadratic equation was utilized to describe the relationship between SPAD readings and leaf age during the leaf senescence period. The rate of decrease in SPAD readings increased with the age of leaves, but the rate was slowed by N application. As leaves in the lower canopy were physiologically older than leaves in the upper canopy, the rate of decrease in SPAD readings was faster in the lower leaves.

  19. A non-destructive method for estimating onion leaf area

    Directory of Open Access Journals (Sweden)

    Córcoles J.I.

    2015-06-01

    Full Text Available Leaf area is one of the most important parameters for characterizing crop growth and development, and its measurement is useful for examining the effects of agronomic management on crop production. It is related to interception of radiation, photosynthesis, biomass accumulation, transpiration and gas exchange in crop canopies. Several direct and indirect methods have been developed for determining leaf area. The aim of this study is to develop an indirect method, based on the use of a mathematical model, to compute leaf area in an onion crop using non-destructive measurements with the condition that the model must be practical and useful as a Decision Support System tool to improve crop management. A field experiment was conducted in a 4.75 ha commercial onion plot irrigated with a centre pivot system in Aguas Nuevas (Albacete, Spain, during the 2010 irrigation season. To determine onion crop leaf area in the laboratory, the crop was sampled on four occasions between 15 June and 15 September. At each sampling event, eight experimental plots of 1 m2 were used and the leaf area for individual leaves was computed using two indirect methods, one based on the use of an automated infrared imaging system, LI-COR-3100C, and the other using a digital scanner EPSON GT-8000, obtaining several images that were processed using Image J v 1.43 software. A total of 1146 leaves were used. Before measuring the leaf area, 25 parameters related to leaf length and width were determined for each leaf. The combined application of principal components analysis and cluster analysis for grouping leaf parameters was used to reduce the number of variables from 25 to 12. The parameter derived from the product of the total leaf length (L and the leaf diameter at a distance of 25% of the total leaf length (A25 gave the best results for estimating leaf area using a simple linear regression model. The model obtained was useful for computing leaf area using a non

  20. Resistance in winter barley against Ramularia leaf spot

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus Lund

    Ramularia leaf spot is an emerging disease in barley caused by R. collo-cygni. At present little is known about the resistance mechanisms carried out by the host plant to avoid disease development. Nor is the lifecycle of the fungus or its populations structure fully understood. To gain insight....... fulvum-tomato and S. tritici-wheat in order to find modelsystems to enhance interpretation of results from R. collo-cygni-barley interaction. Results from the mapping showed that resistance to Ramularia leaf spot is controlled by a number of QTL’s, some of which co-locate with other physiological traits....... The populations further segregated for physiological leaf spots, a phenomenon related to the leaf damage imposed by Rubellin, although, resistance to physiological leafspots appeared to come from the Ramularia leaf spot susceptible parent. The toxin assay further supported this result as the genotypes susceptible...

  1. CIRCADIAN CLOCK-ASSOCIATED 1 Inhibits Leaf Senescence in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yi Song

    2018-03-01

    Full Text Available Leaf senescence is an integral part of plant development, and the timing and progressing rate of senescence could substantially affect the yield and quality of crops. It has been known that a circadian rhythm synchronized with external environmental cues is critical for the optimal coordination of various physiological and metabolic processes. However, the reciprocal interactions between the circadian clock and leaf senescence in plants remain unknown. Here, through measuring the physiological and molecular senescence related markers of several circadian components mutants, we found that CIRCADIAN CLOCK-ASSOCIATED 1 inhibits leaf senescence. Further molecular and genetic studies revealed that CCA1 directly activates GLK2 and suppresses ORE1 expression to counteract leaf senescence. As plants age, the expression and periodic amplitude of CCA1 declines and thus weakens the inhibition of senescence. Our findings reveal an age-dependent circadian clock component of the process of leaf senescence.

  2. Understanding of Leaf Development—the Science of Complexity

    Directory of Open Access Journals (Sweden)

    Robert Malinowski

    2013-06-01

    Full Text Available The leaf is the major organ involved in light perception and conversion of solar energy into organic carbon. In order to adapt to different natural habitats, plants have developed a variety of leaf forms, ranging from simple to compound, with various forms of dissection. Due to the enormous cellular complexity of leaves, understanding the mechanisms regulating development of these organs is difficult. In recent years there has been a dramatic increase in the use of technically advanced imaging techniques and computational modeling in studies of leaf development. Additionally, molecular tools for manipulation of morphogenesis were successfully used for in planta verification of developmental models. Results of these interdisciplinary studies show that global growth patterns influencing final leaf form are generated by cooperative action of genetic, biochemical, and biomechanical inputs. This review summarizes recent progress in integrative studies on leaf development and illustrates how intrinsic features of leaves (including their cellular complexity influence the choice of experimental approach.

  3. CO2 and temperature effects on leaf area production in two annual plant species

    International Nuclear Information System (INIS)

    Ackerly, D.D.; Coleman, J.S.; Morse, S.R.; Bazzaz, F.A.

    1992-01-01

    The authors studied leaf area production in two annual plant species, Abutilon theophrasti and Amaranthus retroflexus, under three day/night temperature regimes and two concentrations of carbon dioxide. The production of whole-plant leaf area during the first 30 d of growth was analyzed in terms of the leaf initiation rate, leaf expansion, individual leaf area, and, in Amaranthus, production of branch leaves. Temperature and CO 2 influenced leaf area production through effects on the rate of development, determined by the production of nodes on the main stem, and through shifts in the relationship between whole-plant leaf area and the number of main stem nodes. In Abutilon, leaf initiation rate was highest at 38 degree, but area of individual leaves was greatest at 28 degree. Total leaf area was greatly reduced at 18 degree due to slow leaf initiation rates. Elevated CO 2 concentration increased leaf initiation rate at 28 degree, resulting in an increase in whole-part leaf area. In Amaranthus, leaf initiation rate increased with temperature, and was increased by elevated CO 2 at 28 degree. Individual leaf area was greatest at 28 degree, and was increased by elevated CO 2 at 28 degree but decreased at 38 degree. Branch leaf area displayed a similar response to CO 2 , butt was greater at 38 degree. Overall, wholeplant leaf area was slightly increased at 38 degree relative to 28 degree, and elevated CO 2 levels resulted in increased leaf area at 28 degree but decreased leaf area at 38 degree

  4. The Effect of Leaf Stacking on Leaf Reflectance and Vegetation Indices Measured by Contact Probe during the Season

    Czech Academy of Sciences Publication Activity Database

    Neuwirthová, E.; Lhotáková, Z.; Albrechtová, Jana

    2017-01-01

    Roč. 17, č. 6 (2017), s. 1-23, č. článku 1202. ISSN 1424-8220 Institutional support: RVO:67985939 Keywords : broadleaved trees * leaf optical properties * leaf traits Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 2.677, year: 2016

  5. Effects of canopy structural variables on retrieval of leaf dry matter content and specific leaf area from remotely sensed data

    NARCIS (Netherlands)

    Ali, A.M.; Darvishzadeh, R.; Skidmore, A.K.; van Duren, I.C.

    2016-01-01

    Leaf dry matter content (LDMC) and specific leaf area (SLA) are two important traits in measuring biodiversity. To use remote sensing for the estimation of these traits, it is essential to understand the underlying factors that influence their relationships with canopy reflectance. The effect of

  6. Antioxidative Activity of Tobacco Leaf Protein Hydrolysates

    Directory of Open Access Journals (Sweden)

    Guohua Rao

    2007-01-01

    Full Text Available Discarded tobacco leaf protein hydrolysate (DTLPH was prepared by enzymatic hydrolysis using papain and then separated using ultrafiltration (UF membranes with molecular mass cut-off (MMCO of 10, 5, 3 and 1 kDa. Four permeate fractions including 10-K, 5-K, 3-K and 1-K (the permeate fractions from 10, 5, 3 and 1 kDa hydrolysate fractions were obtained. The 5-K hydrolysate fraction had high oxidation inhibilitory ratio (42.62 %, which was about twofold higher than the original hydrolysate and as high as that of vitamin E (α-tocopherol. The fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested. Moreover, these separated hydrolysates showed the enhanced functional property. The amino acid composition of 5-K hydrolysate was analyzed and the results show that the high antioxidative activity of 5-K hydrolysate was derived from high content of histidine, methionine, cystine and tryptophan.

  7. Immune defense in leaf-cutting ants

    DEFF Research Database (Denmark)

    Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández

    2011-01-01

    To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross......-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced...... both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily...

  8. Peracylated Glucosyl Kaempferols from Pasania dodonfifolia Leaf.

    Science.gov (United States)

    Chang, Chi-Chih; Lee, Shoei-Sheng

    2015-08-01

    Phytochemical investigation of the ethanolic extract of Pasania dodoniifolia leaf led to the isolation of four kaempferol 3-0-peracylated glucosides (1-4), together with four flavonoid glucosides (5-8), epicatechin (9), and (7S, 7'S, 8R, 8'R)-icariol A2 (10). Of these, kaempferol-3-O-(3",4"-di-O-acetyl-2"-O-(Z)-p- coumaroyl)-6"-O-(E)-p-coumaroyl)-beta-glucopyranoside (3) and 3-O-(3",4"-di-O-acetyl-2",6"-di-O-(Z)-p-coumaroyl)-beta-glucopyranoside (4) are new and their structures were elucidated by 2D NMR spectroscopic analyses and MS data.

  9. Adsorption Studies of Radish Leaf Powder

    Directory of Open Access Journals (Sweden)

    Ankita

    2016-01-01

    Full Text Available Radish leaves (Raphanus sativus powder fractions was subjected to moisture adsorption isotherms at different isothermal temperature conditions from 15-45°C with an equal interval of 10°C. The sorption data obtained in gravimetric static method under 0.11–0.90 water activity conditions were subjected for sorption isotherms and found to be typical sigmoid trend. Experimental data were assessed for the applicability in the prediction through sorption models fitting and found that Polynomial and GAB equations performed well over all fitted models in describing equilibrium moisture content – equilibrium relative humidity (EMC–ERH relationships for shelf stable dehydrated radish leaf powder, over the entire range of temperatures condition under study. The net isosteric heat of sorption, differential entropy and free energy were determined at different temperatures and their dependence was seen with respect to equilibrium moisture content.

  10. Iridoids from leaf extract of Genipa americana

    Directory of Open Access Journals (Sweden)

    Jovelina S.F. Alves

    Full Text Available Abstract Genipa americana L., Rubiaceae, is a plant native from Brazil popularly known as “jenipapo”. Two iridoids, 1-hydroxy-7-(hydroxymethyl-1,4aH,5H,7aH-cyclopenta[c]pyran-4-carbaldehyde (1, and iridoid 7-(hydroxymethyl-1-methoxy-1H,4aH,5H,7aH-cyclopenta[c]pyran-4-carbaldehyde (2 were isolated and identified in the leaf extract of G. americana. Compounds 1 and 2 were identified for the first time in G. americana, and 1 has not been yet described in literature. These substances were analyzed by spectroscopic techniques such as infrared, high resolution mass spectrometry, 1H and 13C 1D; as well as 2D nuclear magnetic resonance. Moreover, the presence of flavonoids was detected by a preliminary analysis by Thin Layer Chromatography.

  11. A hairy-leaf gene, BLANKET LEAF, of wild Oryza nivara increases photosynthetic water use efficiency in rice.

    Science.gov (United States)

    Hamaoka, Norimitsu; Yasui, Hideshi; Yamagata, Yoshiyuki; Inoue, Yoko; Furuya, Naruto; Araki, Takuya; Ueno, Osamu; Yoshimura, Atsushi

    2017-12-01

    High water use efficiency is essential to water-saving cropping. Morphological traits that affect photosynthetic water use efficiency are not well known. We examined whether leaf hairiness improves photosynthetic water use efficiency in rice. A chromosome segment introgression line (IL-hairy) of wild Oryza nivara (Acc. IRGC105715) with the genetic background of Oryza sativa cultivar 'IR24' had high leaf pubescence (hair). The leaf hairs developed along small vascular bundles. Linkage analysis in BC 5 F 2 and F 3 populations showed that the trait was governed by a single gene, designated BLANKET LEAF (BKL), on chromosome 6. IL-hairy plants had a warmer leaf surface in sunlight, probably due to increased boundary layer resistance. They had a lower transpiration rate under moderate and high light intensities, resulting in higher photosynthetic water use efficiency. Introgression of BKL on chromosome 6 from O. nivara improved photosynthetic water use efficiency in the genetic background of IR24.

  12. Models for leaf area estimation in dwarf pigeon pea by leaf dimensions

    Directory of Open Access Journals (Sweden)

    Rafael Vieira Pezzini

    2018-03-01

    Full Text Available ABSTRACT This study aims to determine the most suitable model to estimate the leaf area of dwarf pigeon pea in function of the leaf central leaflet dimension. Six samplings of 200 leaves were performed in the first experiment, at 36, 42, 50, 56, 64, and 72 days after emergence (DAE. In the second experiment, seven samplings of 200 leaves were performed at 29, 36, 43, 49, 57, 65, and 70 DAE, totaling 2600 leaves. The length (L and width (W of the central leaflet were measured in all leaves composed by left, central, and right leaflets, the product of length times width (LW was calculated, and the leaf area (Y – sum of left, central, and right leaflet areas was determined by digital images. Linear, power, quadratic, and cubic models of Y as function of L, W, and LW were built using data from the second experiment. Leaves from the first experiment were used to validate the models. In dwarf pigeon pea, the linear (Ŷ = – 0.4088 + 1.6669x, R2 = 0.9790 is preferable, but power (Ŷ = 1.6097x1.0065, R2 = 0.9766, quadratic (Ŷ = – 0.3625 + 1.663x + 0.00007x2, R2 = 0.9790, and cubic (Ŷ = 0.7216 + 1.522x + 0.005x2 – 5E–05x3, R2 = 0.9791 models in function of LW are also suitable to estimate the leaf area obtained by digital images. The power model (Ŷ = 5.2508x1.7868, R2 = 0.95 based on the central leaflet width is less laborious because requires only one variable, but it presents accuracy reduction.

  13. Leaf morphophysiology of a Neotropical mistletoe is shaped by seasonal patterns of host leaf phenology.

    Science.gov (United States)

    Scalon, Marina Corrêa; Rossatto, Davi Rodrigo; Domingos, Fabricius Maia Chaves Bicalho; Franco, Augusto Cesar

    2016-04-01

    Several mistletoe species are able to grow and reproduce on both deciduous and evergreen hosts, suggesting a degree of plasticity in their ability to cope with differences in intrinsic host functions. The aim of this study was to investigate the influence of host phenology on mistletoe water relations and leaf gas exchange. Mistletoe Passovia ovata parasitizing evergreen (Miconia albicans) hosts and P. ovata parasitizing deciduous (Byrsonima verbascifolia) hosts were sampled in a Neotropical savanna. Photosynthetic parameters, diurnal cycles of stomatal conductance, pre-dawn and midday leaf water potential, and stomatal anatomical traits were measured during the peak of the dry and wet seasons, respectively. P. ovata showed distinct water-use strategies that were dependent on host phenology. For P. ovata parasitizing the deciduous host, water use efficiency (WUE; ratio of photosynthetic rate to transpirational water loss) was 2-fold lower in the dry season than in the wet season; in contrast, WUE was maintained at the same level during the wet and dry seasons in P. ovata parasitizing the evergreen host. Generally, mistletoe and host diurnal cycles of stomatal conductance were linked, although there were clear differences in leaf water potential, with mistletoe showing anisohydric behaviour and the host showing isohydric behaviour. Compared to mistletoes attached to evergreen hosts, those parasitizing deciduous hosts had a 1.4-fold lower stomatal density and 1.2-fold wider stomata on both leaf surfaces, suggesting that the latter suffered less intense drought stress. This is the first study to show morphophysiological differences in the same mistletoe species parasitizing hosts of different phenological groups. Our results provide evidence that phenotypical plasticity (anatomical and physiological) might be essential to favour the use of a greater range of hosts.

  14. Computer controlled multi-leaf conformation radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, T [Tokyo Metropolitan Komagome Hospital (Japan); Inamura, K

    1981-10-01

    A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer.

  15. Computer controlled multi-leaf conformation radiotherapy

    International Nuclear Information System (INIS)

    Matsuda, Tadayoshi; Inamura, Kiyonari.

    1981-01-01

    A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer. (author)

  16. Global variability in leaf respiration in relation to climate, plant functional types and leaf traits.

    Science.gov (United States)

    Atkin, Owen K; Bloomfield, Keith J; Reich, Peter B; Tjoelker, Mark G; Asner, Gregory P; Bonal, Damien; Bönisch, Gerhard; Bradford, Matt G; Cernusak, Lucas A; Cosio, Eric G; Creek, Danielle; Crous, Kristine Y; Domingues, Tomas F; Dukes, Jeffrey S; Egerton, John J G; Evans, John R; Farquhar, Graham D; Fyllas, Nikolaos M; Gauthier, Paul P G; Gloor, Emanuel; Gimeno, Teresa E; Griffin, Kevin L; Guerrieri, Rossella; Heskel, Mary A; Huntingford, Chris; Ishida, Françoise Yoko; Kattge, Jens; Lambers, Hans; Liddell, Michael J; Lloyd, Jon; Lusk, Christopher H; Martin, Roberta E; Maksimov, Ayal P; Maximov, Trofim C; Malhi, Yadvinder; Medlyn, Belinda E; Meir, Patrick; Mercado, Lina M; Mirotchnick, Nicholas; Ng, Desmond; Niinemets, Ülo; O'Sullivan, Odhran S; Phillips, Oliver L; Poorter, Lourens; Poot, Pieter; Prentice, I Colin; Salinas, Norma; Rowland, Lucy M; Ryan, Michael G; Sitch, Stephen; Slot, Martijn; Smith, Nicholas G; Turnbull, Matthew H; VanderWel, Mark C; Valladares, Fernando; Veneklaas, Erik J; Weerasinghe, Lasantha K; Wirth, Christian; Wright, Ian J; Wythers, Kirk R; Xiang, Jen; Xiang, Shuang; Zaragoza-Castells, Joana

    2015-04-01

    Leaf dark respiration (Rdark ) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of Rdark and associated leaf traits. Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed-effects models were used to disentangle sources of variation in Rdark . Area-based Rdark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8-28°C). By contrast, Rdark at a standard T (25°C, Rdark (25) ) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher Rdark (25) at a given photosynthetic capacity (Vcmax (25) ) or leaf nitrogen concentration ([N]) than species at warmer sites. Rdark (25) values at any given Vcmax (25) or [N] were higher in herbs than in woody plants. The results highlight variation in Rdark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of Rdark in terrestrial biosphere models (TBMs) and associated land-surface components of Earth system models (ESMs). © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  17. Stretchable and High-Performance Supercapacitors with Crumpled Graphene Papers

    OpenAIRE

    Zang, Jianfeng; Cao, Changyong; Feng, Yaying; Liu, Jie; Zhao, Xuanhe

    2014-01-01

    Fabrication of unconventional energy storage devices with high stretchability and performance is challenging, but critical to practical operations of fully power-independent stretchable electronics. While supercapacitors represent a promising candidate for unconventional energy-storage devices, existing stretchable supercapacitors are limited by their low stretchability, complicated fabrication process, and high cost. Here, we report a simple and low-cost method to fabricate extremely stretch...

  18. TALE and Shape: How to Make a Leaf Different.

    Science.gov (United States)

    Di Giacomo, Elisabetta; Iannelli, Maria Adelaide; Frugis, Giovanna

    2013-05-06

    The Three Amino acid Loop Extension (TALE) proteins constitute an ancestral superclass of homeodomain transcription factors conserved in animals, plants and fungi. In plants they comprise two classes, KNOTTED1-LIKE homeobox (KNOX) and BEL1-like homeobox (BLH or BELL, hereafter referred to as BLH), which are involved in shoot apical meristem (SAM) function, as well as in the determination and morphological development of leaves, stems and inflorescences. Selective protein-protein interactions between KNOXs and BLHs affect heterodimer subcellular localization and target affinity. KNOXs exert their roles by maintaining a proper balance between undifferentiated and differentiated cell state through the modulation of multiple hormonal pathways. A pivotal function of KNOX in evolutionary diversification of leaf morphology has been assessed. In the SAM of both simple- and compound-leafed seed species, downregulation of most class 1 KNOX (KNOX1) genes marks the sites of leaf primordia initiation. However, KNOX1 expression is re-established during leaf primordia development of compound-leafed species to maintain transient indeterminacy and morphogenetic activity at the leaf margins. Despite the increasing knowledge available about KNOX1 protein function in plant development, a comprehensive view on their downstream effectors remains elusive. This review highlights the role of TALE proteins in leaf initiation and morphological plasticity with a focus on recent advances in the identification of downstream target genes and pathways.

  19. Importance of Secondary Metabolites for Leaf Beetles (Coleoptera: Chrysomelidae

    Directory of Open Access Journals (Sweden)

    A. N. EKİZ

    2014-06-01

    Full Text Available Leaf beetles (Chrysomelidae are one of the most diverse families of herbivorous insects. Many of them are important agricultural pests and cause remarkable loss of crop and money as well. Plant leaves and roots are primary food source of both larva and adults of leaf beetles. Plants produce many secondary metabolites in reaction to herbivore insects. It is a well-known phenomenon that quantity and variety of secondary metabolites in plant leaves may change in response to insect attacks. Herbivore insects have to deal with such defensive secondary chemicals and overcome either by detoxifying or storing them. Accordingly, many specialist herbivores coevolved with their host plant. Certain phenolic glycosides may reduce leaf beetle feeding. Condensed tannins are anti-herbivore defenses against leaf chewing beetles, including leaf beetles. Flavonoid compounds are feeding deterrents for many flea leaf beetles. Cinnamic acid derivatives are other known feeding deterrents for leaf beetles. Secondary metabolites quantity and nutritional quality of host plants are not only important for feeding but also for providing enemy-free space and suitable oviposition sites.

  20. Scaling up stomatal conductance from leaf to canopy using a dual-leaf model for estimating crop evapotranspiration.

    Directory of Open Access Journals (Sweden)

    Risheng Ding

    Full Text Available The dual-source Shuttleworth-Wallace model has been widely used to estimate and partition crop evapotranspiration (λET. Canopy stomatal conductance (Gsc, an essential parameter of the model, is often calculated by scaling up leaf stomatal conductance, considering the canopy as one single leaf in a so-called "big-leaf" model. However, Gsc can be overestimated or underestimated depending on leaf area index level in the big-leaf model, due to a non-linear stomatal response to light. A dual-leaf model, scaling up Gsc from leaf to canopy, was developed in this study. The non-linear stomata-light relationship was incorporated by dividing the canopy into sunlit and shaded fractions and calculating each fraction separately according to absorbed irradiances. The model includes: (1 the absorbed irradiance, determined by separately integrating the sunlit and shaded leaves with consideration of both beam and diffuse radiation; (2 leaf area for the sunlit and shaded fractions; and (3 a leaf conductance model that accounts for the response of stomata to PAR, vapor pressure deficit and available soil water. In contrast to the significant errors of Gsc in the big-leaf model, the predicted Gsc using the dual-leaf model had a high degree of data-model agreement; the slope of the linear regression between daytime predictions and measurements was 1.01 (R2 = 0.98, with RMSE of 0.6120 mm s-1 for four clear-sky days in different growth stages. The estimates of half-hourly λET using the dual-source dual-leaf model (DSDL agreed well with measurements and the error was within 5% during two growing seasons of maize with differing hydrometeorological and management strategies. Moreover, the estimates of soil evaporation using the DSDL model closely matched actual measurements. Our results indicate that the DSDL model can produce more accurate estimation of Gsc and λET, compared to the big-leaf model, and thus is an effective alternative approach for estimating and

  1. Optimal leaf positions for chlorophyll meter measurement in rice

    Directory of Open Access Journals (Sweden)

    Zhaofeng eYuan

    2016-05-01

    Full Text Available The Soil Plant Analysis Development (SPAD chlorophyll meter is one of the most commonly used diagnostic tools to measure crop nitrogen status. However, the measurement method of the meter could significantly affect the accuracy of the final estimation. Thus, this research was undertaken to develop a new methodology to optimize SPAD meter measurements in rice (Oryza sativa L.. A flatbed color scanner was used to map the dynamic chlorophyll distribution and irregular leaf shapes. Calculus algorithm was adopted to estimate the potential positions for SPAD meter measurement along the leaf blade. Data generated by the flatbed color scanner and SPAD meter were analysed simultaneously. The results suggested that a position 2/3 of the distance from the leaf base to the apex (2/3 position could represent the chlorophyll content of the entire leaf blade, as indicated by the relatively low variance of measurements at that positon. SPAD values based on di-positional leaves and the extracted chlorophyll a and b contents were compared. This comparison showed that the 2/3 position on the lower leaves tended to be more sensitive to changes in chlorophyll content. Finally, the 2/3 position and average SPAD values of the fourth fully expanded leaf from the top were compared with leaf nitrogen concentration. The results showed the 2/3 position on that leaf was most suitable for predicting the nitrogen status of rice. Based on these results, we recommend making SPAD measurements at the 2/3 position on the fourth fully expanded leaf from the top. The coupling of dynamic chlorophyll distribution and irregular leaf shapes information can provide a promising approach for the calibration of SPAD meter measurement, which can further benefit the in situ nitrogen management by providing reliable estimation of crops nitrogen nutrition status.

  2. Leaf application of silicic acid to upland rice and corn

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol

    2013-12-01

    Full Text Available This study aimed to evaluate the effect of Si (stabilized silicic acid, Silamol® leaf application on mineral nutrition and yield in upland rice and corn crops. The treatments were the control (without Si and Si foliar split spraying using 2 L ha-1 of the Silamol® commercial product, with 0.8% soluble Si as concentrated stabilized silicic acid. Silicon leaf application increased the concentrations of K, Ca and Si in rice and corn leaves, the number of panicles per m2 of rice and the number of grains per ear of corn; accordingly, the Si leaf application provided a higher grain yield in both crops.

  3. Natural Pineapple Leaf Fibre Extraction On Josapine And Morris

    OpenAIRE

    Mazalan Muhammad Firdaus; Yusof Yusri

    2017-01-01

    The pineapple’s leaf plant contains approximately 2.5% to 3.5% of strong white silky fibres. These fibres are useful and can be extracted from the leaves. There are a few ways to extract the fibre such as hand scrapping and by extraction machine. The objective of this research is to study the quality of fibre extraction by using different age of pineapple leaf. Next, the study aims to compare the quality of Josapine and Morris pineapple leaf with tensile test. Fibre yield percentage are calcu...

  4. The action spectrum in chloroplast translocation in multilayer leaf cells

    Directory of Open Access Journals (Sweden)

    Zbigniew Lechowski

    2015-01-01

    Full Text Available By measurement of light transmittance through a leaf as criterion of chloroplast translocation, the action spectrum of Ajuga reptans was established. In the spectrum obtained, a correction was introduced for leaf autoabsorption calculated on the basis of the Beer-Lambert law. The action spectrum has two maxima: at λ= 375 nm and λ= 481 nm. The range above 502 nm has no significant effect on chloroplast translocation. Comparison with other objects examined demonstrated that in multilayer leaf cells riboflavin seems also to be a photoreceptor active in this process.

  5. Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant.

    Science.gov (United States)

    Shi, Pei-Jian; Xu, Qiang; Sandhu, Hardev S; Gielis, Johan; Ding, Yu-Long; Li, Hua-Rong; Dong, Xiao-Bo

    2015-10-01

    The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a -3/2 power between average biomass and density or a -1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.

  6. Leaf extraction and analysis framework graphical user interface: segmenting and analyzing the structure of leaf veins and areoles.

    Science.gov (United States)

    Price, Charles A; Symonova, Olga; Mileyko, Yuriy; Hilley, Troy; Weitz, Joshua S

    2011-01-01

    Interest in the structure and function of physical biological networks has spurred the development of a number of theoretical models that predict optimal network structures across a broad array of taxonomic groups, from mammals to plants. In many cases, direct tests of predicted network structure are impossible given the lack of suitable empirical methods to quantify physical network geometry with sufficient scope and resolution. There is a long history of empirical methods to quantify the network structure of plants, from roots, to xylem networks in shoots and within leaves. However, with few exceptions, current methods emphasize the analysis of portions of, rather than entire networks. Here, we introduce the Leaf Extraction and Analysis Framework Graphical User Interface (LEAF GUI), a user-assisted software tool that facilitates improved empirical understanding of leaf network structure. LEAF GUI takes images of leaves where veins have been enhanced relative to the background, and following a series of interactive thresholding and cleaning steps, returns a suite of statistics and information on the structure of leaf venation networks and areoles. Metrics include the dimensions, position, and connectivity of all network veins, and the dimensions, shape, and position of the areoles they surround. Available for free download, the LEAF GUI software promises to facilitate improved understanding of the adaptive and ecological significance of leaf vein network structure.

  7. Does investment in leaf defenses drive changes in leaf economic strategy? A focus on whole-plant ontogeny.

    Science.gov (United States)

    Mason, Chase M; Donovan, Lisa A

    2015-04-01

    Leaf defenses have long been studied in the context of plant growth rate, resource availability, and optimal investment theory. Likewise, one of the central modern paradigms of plant ecophysiology, the leaf economics spectrum (LES), has been extensively studied in the context of these factors across ecological scales ranging from global species data sets to temporal shifts within individuals. Despite strong physiological links between LES strategy and leaf defenses in structure, function, and resource investment, the relationship between these trait classes has not been well explored. This study investigates the relationship between leaf defenses and LES strategy across whole-plant ontogeny in three diverse Helianthus species known to exhibit dramatic ontogenetic shifts in LES strategy, focusing primarily on physical and quantitative chemical defenses. Plants were grown under controlled environmental conditions and sampled for LES and defense traits at four ontogenetic stages. Defenses were found to shift strongly with ontogeny, and to correlate strongly with LES strategy. More advanced ontogenetic stages with more conservative LES strategy leaves had higher tannin activity and toughness in all species, and higher leaf dry matter content in two of three species. Modeling results in two species support the conclusion that changes in defenses drive changes in LES strategy through ontogeny, and in one species that changes in defenses and LES strategy are likely independently driven by ontogeny. Results of this study support the hypothesis that leaf-level allocation to defenses might be an important determinant of leaf economic traits, where high investment in defenses drives a conservative LES strategy.

  8. An analytical approach for optimizing the leaf design of a multi-leaf collimator in a linear accelerator

    International Nuclear Information System (INIS)

    Topolnjak, R; Heide, U A van der

    2008-01-01

    In this study, we present an analytical approach for optimizing the leaf design of a multi-leaf collimator (MLC) in a linear accelerator. Because leaf designs vary between vendors, our goal is to characterize and quantify the effects of different compromises which have to be made between performance parameters. Subsequently, an optimal leaf design for an earlier proposed six-bank MLC which combines a high-resolution field-shaping ability with a large field size is determined. To this end a model of the linac is created that includes the following parameters: the source size, the maximum field size, the distance between source and isocenter, and the leaf's design parameters. First, the optimal radius of the leaf tip was found. This optimum was defined by the requirement that the fluence intensity should fall from 80% of the maximum value to 20% in a minimal distance, defining the width of the fluence penumbra. A second requirement was that this penumbra width should be constant when a leaf moves from one side of the field to the other. The geometric, transmission and total penumbra width (80-20%) were calculated depending on the design parameters. The analytical model is in agreement with Elekta, Varian and Siemens collimator designs. For leaves thinner than 4 cm, the transmission penumbra becomes dominant, and for leaves close to the source the geometric penumbra plays a role. Finally, by choosing the leaf thickness of 3.5 cm, 4 cm and 5 cm from the lowest to the highest bank, respectively, an optimal leaf design for a six-bank MLC is achieved

  9. Infrared remote sensing for canopy temperature in paddy field and relationship between leaf temperature and leaf color

    International Nuclear Information System (INIS)

    Wakiyama, Y.

    2002-01-01

    Infrared remote sensing is used for crop monitoring, for example evaluation of water stress, detection of infected crops and estimation of transpiration and photosynthetic rates. This study was conducted to show another application of remote sensing information. The relationship between rice leaf temperature and chlorophyll content in the leaf blade was investigated by using thermography during the ripening period. The canopy of a rice community fertilized by top dressing was cooler than that not fertilized in a 1999 field experiment. In an experiment using thermocouples to measure leaf temperature, a rice leaf with high chlorophyll content was also cooler than that with a low chlorophyll content. Transpiration resistance and transpiration rate were measured with a porometer. Transpiration rate was higher with increasing chlorophyll content in the leaf blade. Stomatal aperture is related to chlorophyll content in the leaf blade. High degree of stomatal aperture is caused by high chlorophyll content in the leaf blade. As degree of stomatal aperture increases, transpiration rate increases. Therefore the rice leaf got cooler with increasing chlorophyll content in leaf blade. Paddy rice communities with different chlorophyll contents were provided with fertilization of different nitrogen levels on basal and top dressing in a 2000 field experiment. Canopy temperature of the rice community with high chlorophyll content was 0.85°C cooler than that of the rice community with low chlorophyll content. Results of this study revealed that infrared remote sensing could detect difference in chlorophyll contents in rice communities and could be used in fertilizer management in paddy fields. (author)

  10. Antioxidant Activity and Cytotoxicity of the Leaf and Bark Extracts of ...

    African Journals Online (AJOL)

    Purpose: To investigate the antioxidant potential and cytotoxicity of the leaf and bark extracts of Tarchonanathus campharatus.. Methods: The antioxidant activity of the aqueous leaf extract (Aq LF), methanol leaf extract (MET LF), dichloromethane leaf extract (DCM LF), methanol bark extract (MET BK), dichloromethane bark ...

  11. Leaf litter processing in West Virginia mountain streams: effects of temperature and stream chemistry

    Science.gov (United States)

    Jacquelyn M. Rowe; William B. Perry; Sue A. Perry

    1996-01-01

    Climate change has the potential to alter detrital processing in headwater streams, which receive the majority of their nutrient input as terrestrial leaf litter. Early placement of experimental leaf packs in streams, one month prior to most abscission, was used as an experimental manipulation to increase stream temperature during leaf pack breakdown. We studied leaf...

  12. Molecular characterization of two isolates of sweet potato leaf curl ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... related to that of sweet potato leaf curl virus (SPLCV) from United States with nucleotide sequence identity of ... species including Ipomoea indica, are grown orna- mentally all .... and AC4 were closely related to that of SPLCV-.

  13. Genetic control of leaf-blade morphogenesis by the INSECATUS ...

    Indian Academy of Sciences (India)

    2010-08-03

    Aug 3, 2010 ... demonstrated that the leaflet shape is dependent on the venation pattern. [Kumar S. ..... The spectrum of regulatory events is exemplified with respect to first .... exclusive as well as additive roles, in both leaf-blade rachis.

  14. Effect of Interaction of Methanol Leaf Extract of Spondias mombin ...

    African Journals Online (AJOL)

    Purpose: To study the effect of interaction between methanol leaf extract of Spondias mombin and ... Keywords: Diarrheagenic E. coli, Drug interaction, Spondias mombin, Amoxicillin, ..... coli isolated from cattle, food, and children during a one-.

  15. Systematic leaf anatomy of Baccaurea, Distichirhops, and Nothobaccaurea (Euphorbiaceae)

    NARCIS (Netherlands)

    Bodegom, S.; Haegens, R.M.A.P.; Heuven, van B.J.; Baas, P.

    2001-01-01

    The leaf anatomical diversity of the genera Baccaurea Lour. (43 species), Distichirhops Haegens (3 species) and Nothobaccaurea Haegens (2 species) (Euphorbiaceae) is described. Two species of Aporosa and three species of Maesobotrya were examined for comparison. The following characters are

  16. Induced resistance and gene expression in wheat against leaf rust ...

    African Journals Online (AJOL)

    uvp

    2013-05-15

    May 15, 2013 ... 2Department of Soil, Crop and Climate Sciences, University of the Free State, P.O Box ... Key words: Wheat leaf rust, induced resistance, priming, gene ..... transformation: susceptibility of transgenic Nicotiana sylvestris plants.

  17. A comparative evaluation of leaf meals of pawpaw ( C. papaya ...

    African Journals Online (AJOL)

    A comparative evaluation of leaf meals of pawpaw ( C. papaya ), swordbean ( C. gladiate ), jackbean ( C. ensiformis ) and pigeonpea ( C. cajan ) as feed ingredients and yolk colouring agents in layers' diets.

  18. Effect of Carica papaya (Linn) aqueous leaf extract on ...

    African Journals Online (AJOL)

    Effect of Carica papaya (Linn) aqueous leaf extract on pharmacokinetic ... Keywords: Carica papaya, Ciprofloxacin, Sickle cell anaemia, Herb-drug interaction, Pharmacokinetics. Tropical ..... and reproduction in any medium, provided the.

  19. Genetic characterization of angular leaf spot resistance in selected ...

    African Journals Online (AJOL)

    Mr Tryphone

    2015-10-28

    Oct 28, 2015 ... Angular leaf spot disease (ALS) caused by Pseudocercospora griseola is one ... Author(s) agree that this article remains permanently open access under the terms ... that results in shrivelled seeds of reduced size and quality.

  20. prevalence of angular leaf spot disease and sources of resistance

    African Journals Online (AJOL)

    USER

    2017-02-17

    Feb 17, 2017 ... Angular leaf spot (Pseudocercospora griseola Crous U, Brown) is one of the ..... Incidence of six foliar bean diseases in two agro ecological zones of eastern Democratic Republic of .... use of poor quality farmer-saved seed.

  1. Monitoring leaf photosynthesis with canopy spectral reflectance in rice

    International Nuclear Information System (INIS)

    Tian, Y.; Zhu, Y.; Cao, W.

    2005-01-01

    We determined the quantitative relationships between leaf photosynthetic characteristics (LPC) and canopy spectral reflectance under different water supply and nitrogen application rates in rice plants. The responses of reflectance at red radiation (680 nm) to different water contents and N rates were parallel to those of leaf net photosynthetic rate (PN). The relationships of reflectance at 680 nm and ratio index of R(810,680) (near infrared/red) to PN of different leaf positions and layers indicated that the top two full leaves were the best positions for quantitative monitoring of PN with remote sensing technique, and the index R(810,680) was the best ratio index for evaluating LPC. Testing of the models with independent data sets indicated that R(810,680) could well estimate PN of the top two leaves and canopy leaf photosynthetic potential. Hence R(810,680) can be used to monitor LPC in rice under diverse growing conditions

  2. Antibacterial activity of mangrove leaf extracts against human pathogens

    Digital Repository Service at National Institute of Oceanography (India)

    Sahoo, G.; Mulla, N.S.S.; Ansari, Z.A.; Mohandass, C.

    ., Salmonella typhi, Proteus vulgaris and Proteus mirabilis. As compared to aqueous, ethanol extract showed broad-spectrum activity. The multidrug-resistant (MDR) bacteria Salmonella typhi was inhibited by the ethanol extract of S. alba leaf whereas the other...

  3. Micro- and nanoscale characterization of hydrophobic and hydrophilic leaf surfaces

    International Nuclear Information System (INIS)

    Bhushan, Bharat; Jung, Yong Chae

    2006-01-01

    Superhydrophobic surfaces as well as low adhesion and friction are desirable for various industrial applications. Certain plant leaves are known to be hydrophobic in nature due to their roughness and the presence of a thin wax film on the surface of the leaf. The purpose of this study is to fully characterize the leaf surfaces on the micro- and nanoscale while separating out the effects of the micro- and the nanobumps of hydrophobic leaves on the hydrophobicity. Hydrophilic leaves were also studied to better understand the role of wax and roughness. Furthermore, the adhesion and friction properties of hydrophobic and hydrophilic leaves were studied. Using an optical profiler and an atomic/friction force microscope (AFM/FFM), measurements were made to fully characterize the leaf surfaces. It is shown that the nanobumps play a more important role than the microbumps in the hydrophobic nature as well as friction of the leaf. This study will be useful in developing superhydrophobic surfaces

  4. Effects of methanol leaf extracts of Loranthus micranthus Linn from ...

    African Journals Online (AJOL)

    blood glucose, lipid profile and other biochemical indices of diabetic rats. Methods: The ... Diabetes mellitus is a disease of metabolic origin which is .... Fasting blood sugar level after ..... (Iridaceae) leaf extract in ICR mice fed high fat diet.

  5. Mangifera indica L. leaf extract alleviates doxorubicin induced cardiac stress

    Directory of Open Access Journals (Sweden)

    Laxit Bhatt

    2017-09-01

    Conclusion: The present findings clearly suggest the protective role of alcoholic leaf extract of M. indica against oxidative stress induced by doxorubicin. [J Complement Med Res 2017; 6(3.000: 284-289

  6. Gold leaf counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Shimada, Kazuhiro; Toyoda, Takeshi

    2018-03-01

    In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

  7. Phytochemical Analysis, Antifungal and Antioxidant Activity of Leaf ...

    African Journals Online (AJOL)

    Science, Technology and Arts Research Journal ... of total phenolics, antifungal and antioxidant activity of leaf and fruit extract of Zizyphus xylopyrus (Retz.) ... Flavonoids, saponins, terpenoids, tannins and phenols were found in both extracts.

  8. Soome maiustustetootja Leaf saab peatselt uue omaniku / Tõnis Arnover

    Index Scriptorium Estoniae

    Arnover, Tõnis, 1952-

    2004-01-01

    Hollandi kontsern CSM otsustas loobuda maiustusetootmisest, sh. Soome magusatootjast Leaf ning keskenduda pagaritööstustoorme, biokemikaalide ning suhkrutoodete valmistamisele. Diagramm: CSMi kasumlikkus vähenes. Vt. samas: Eestis menukad kurgupastillid

  9. Reproductive ecology of Commerson's leaf-nosed bats ...

    African Journals Online (AJOL)

    Reproductive ecology of Commerson's leaf-nosed bats Hipposideros commersoni ... Reproductive females dispersed twice during the annual cycle, while in ... Synchronized parturitions within maternity roosts (in late October) created a hot, ...

  10. Automated rice leaf disease detection using color image analysis

    Science.gov (United States)

    Pugoy, Reinald Adrian D. L.; Mariano, Vladimir Y.

    2011-06-01

    In rice-related institutions such as the International Rice Research Institute, assessing the health condition of a rice plant through its leaves, which is usually done as a manual eyeball exercise, is important to come up with good nutrient and disease management strategies. In this paper, an automated system that can detect diseases present in a rice leaf using color image analysis is presented. In the system, the outlier region is first obtained from a rice leaf image to be tested using histogram intersection between the test and healthy rice leaf images. Upon obtaining the outlier, it is then subjected to a threshold-based K-means clustering algorithm to group related regions into clusters. Then, these clusters are subjected to further analysis to finally determine the suspected diseases of the rice leaf.

  11. Evaluating a tobacco leaf humidification system involving nebulisation

    Directory of Open Access Journals (Sweden)

    Néstor Enrique Cerquera Peña

    2010-05-01

    Full Text Available A tobacco leaf humidifying system involving nebulisation was designned, implemented and evaluated; it had a system for monitoring and recording environmental conditions thereby producing an environment having more homogeneous relative humidity, ensuring better water use, better control of relative humidity and better control in managing cured tobacco leaf moisture content, thereby leading to a consequent improvement in final product quality. 55% to 75% relative humidity and 4 to 6 hour working ranges were obtained to en- sure leaf humidification reached 16% humidity on a wet basis. Two new designs are proposed for the conditioning stage regarding this conditioning chamber’s operational management, based on the results and field observations, which would allow better leaf management, thereby avoiding the risk of losses due to manipulation and over-humidification. This work strengthens research in the field of tobacco pos- tharvest technology, complementing other research projects which have been carried out in Colombia.

  12. Phytochemical and analgesic evaluation of methanol leaf extract of ...

    African Journals Online (AJOL)

    Phytochemical and analgesic evaluation of methanol leaf extract of ... Thirty minutes prior to intraperitoneal injection with 2 ml of 0.1% acetic acid, animals in groups ... (acetaminophen), aspirin and indomethacin while VII received saline water.

  13. Novel fungal disease in complex leaf-cutting ant societies

    DEFF Research Database (Denmark)

    Hughes, David Peter; Evans, Harry C.; Hywel-Jones, Nigel

    2009-01-01

    1. The leaf-cutting ants practise an advanced system of mycophagy where they grow a fungus as a food source. As a consequence of parasite threats to their crops, they have evolved a system of morphological, behavioural, and chemical defences, particularly against fungal pathogens (mycopathogens). 2....... Specific fungal diseases of the leaf-cutting ants themselves have not been described, possibly because broad spectrum anti-fungal defences against mycopathogens have reduced their susceptibility to entomopathogens. 3. Using morphological and molecular tools, the present study documents three rare infection...... events of Acromyrmex and Atta leaf-cutting ants by Ophiocordyceps fungi, agenus of entomopathogens that is normally highly specific in its host choice. 4. As leaf-cutting ants have been intensively studied, the absence of prior records of Ophiocordyceps suggests that these infections may be a novel event...

  14. Effect of Moringa oleifera leaf meal on finisher pig growth ...

    African Journals Online (AJOL)

    Effect of Moringa oleifera leaf meal on finisher pig growth performance, meat ... pig growth performance, meat quality, shelf life and fatty acid composition of pork ... negative effect on feed conversion efficiency, carcass and meat quality traits, ...

  15. Developing markers for Sigatoka leaf spot disease (Mycosphaerella ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... Developing markers for Sigatoka leaf spot disease ... OPERON primer pairs were used to screen genomic DNA from two resistant cultivars: Calcutta 4 ( ..... Blomme G, Eden-Green S, Mustaffa M, Nwauzoma B, Thangavelu R.

  16. (CI 42053) from an aqueous solution using Azadirachta indica leaf

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-05

    Nov 5, 2008 ... ... 42053) from an aqueous solution using Azadirachta indica leaf powder as a low- ... and biodegradable effective adsorbents. They were ob- tained from ... pesticide. The trees are also known as an air purifier. The medicinal.

  17. Leaf water stable isotopes and water transport outside the xylem.

    Science.gov (United States)

    Barbour, M M; Farquhar, G D; Buckley, T N

    2017-06-01

    How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

  18. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Mona Singh

    2017-12-08

    Dec 8, 2017 ... Abstract. This study was undertaken to pyramid two effective leaf rust resistance genes (Lr19 and Lr24) derived from ... genes such as Lr9, Lr19, Lr26 and Lr28 became ineffective ..... Disease management recommendations.

  19. Influence of spectral properties on cassava leaf development and ...

    African Journals Online (AJOL)

    sunny t

    2014-02-12

    Feb 12, 2014 ... changes in leaf spectral characteristics were studied using Digimizer ... main wavelengths used by plants (blue, green and red) with the blue being the most preferred. Total ...... differences observed allude to plant behavior.

  20. Leaf transpiration efficiency of some drought-resistant maize lines

    Science.gov (United States)

    Field measurements of leaf gas exchange in maize often indicate stomatal conductances higher than required to provide substomatal carbon dioxide concentrations saturating to photosynthesis. Thus maize leaves often operate at lower transpiration efficiency (TE) than potentially achievable for specie...

  1. Leaf hydraulic conductance declines in coordination with photosynthesis, transpiration and leaf water status as soybean leaves age regardless of soil moisture

    Science.gov (United States)

    Locke, Anna M.; Ort, Donald R.

    2014-01-01

    Photosynthesis requires sufficient water transport through leaves for stomata to remain open as water transpires from the leaf, allowing CO2 to diffuse into the leaf. The leaf water needs of soybean change over time because of large microenvironment changes over their lifespan, as leaves mature in full sun at the top of the canopy and then become progressively shaded by younger leaves developing above. Leaf hydraulic conductance (K leaf), a measure of the leaf’s water transport capacity, can often be linked to changes in microenvironment and transpiration demand. In this study, we tested the hypothesis that K leaf would decline in coordination with transpiration demand as soybean leaves matured and aged. Photosynthesis (A), stomatal conductance (g s) and leaf water potential (Ψleaf) were also measured at various leaf ages with both field- and chamber-grown soybeans to assess transpiration demand. K leaf was found to decrease as soybean leaves aged from maturity to shading to senescence, and this decrease was strongly correlated with midday A. Decreases in K leaf were further correlated with decreases in g s, although the relationship was not as strong as that with A. Separate experiments investigating the response of K leaf to drought demonstrated no acclimation of K leaf to drought conditions to protect against cavitation or loss of g s during drought and confirmed the effect of leaf age in K leaf observed in the field. These results suggest that the decline of leaf hydraulic conductance as leaves age keeps hydraulic supply in balance with demand without K leaf becoming limiting to transpiration water flux. PMID:25281701

  2. Leaf mineral nutrient remobilization during leaf senescence and modulation by nutrient deficiency.

    Directory of Open Access Journals (Sweden)

    Anne eMaillard

    2015-05-01

    Full Text Available Higher plants have to cope with fluctuating mineral resource availability. However strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare and tree species (Quercus robur, Populus nigra, Alnus glutinosa grown under field conditions were harvested regularly during their life span and analysed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize to 90% (wheat, other macronutrients (K-P-S-Mg were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu-Mo-Ni-B-Fe-Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N-S-Cu or increased by nutrient deficiency (K-P-Mg while nutrient deficiency had no effect on Mo-Zn-B-Ca-Mn, which seemed to be non-mobile during leaf senescence under field conditions. However, Ca and Mn were largely mobilized from roots (-97 and -86% of their initial root contents, respectively to shoots. Differences in remobilization between species and between nutrients are then discussed in relation to a range of putative mechanisms.

  3. Bacterial anoxygenic photosynthesis on plant leaf surfaces.

    Science.gov (United States)

    Atamna-Ismaeel, Nof; Finkel, Omri; Glaser, Fabian; von Mering, Christian; Vorholt, Julia A; Koblížek, Michal; Belkin, Shimshon; Béjà, Oded

    2012-04-01

    The aerial surface of plants, the phyllosphere, is colonized by numerous bacteria displaying diverse metabolic properties that enable their survival in this specific habitat. Recently, we reported on the presence of microbial rhodopsin harbouring bacteria on the top of leaf surfaces. Here, we report on the presence of additional bacterial populations capable of harvesting light as a means of supplementing their metabolic requirements. An analysis of six phyllosphere metagenomes revealed the presence of a diverse community of anoxygenic phototrophic bacteria, including the previously reported methylobacteria, as well as other known and unknown phototrophs. The presence of anoxygenic phototrophic bacteria was also confirmed in situ by infrared epifluorescence microscopy. The microscopic enumeration correlated with estimates based on metagenomic analyses, confirming both the presence and high abundance of these microorganisms in the phyllosphere. Our data suggest that the phyllosphere contains a phylogenetically diverse assemblage of phototrophic species, including some yet undescribed bacterial clades that appear to be phyllosphere-unique. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  4. An Outbreak of Foxglove Leaf Poisoning

    Directory of Open Access Journals (Sweden)

    Chun-Chi Lin

    2010-02-01

    Full Text Available Comfrey (Symphytum officinale leaves resemble those of foxglove (Digitalis purpurea when the plant is not in bloom and, therefore, cardiac glycoside poisoning may occur when people confuse foxglove with comfrey. We report an outbreak of foxglove leaf poisoning following the use of alleged “comfrey” herbal tea. Nine patients were involved and initially presented with nausea, vomiting, diarrhea and dizziness. Significant cardiotoxicity developed later among the 3 patients who also had mild hyperkalemia. Peak serum digoxin concentration measured by immunoassay was elevated in all patients and ranged from 4.4 ng/mL to 139.5 ng/mL. Patients with severe cardiotoxicity were treated with temporary cardiac pacing. Moreover, 40–80 mg of digoxin-specific antibody therapy was given without any effect. All patients recovered uneventfully. Our report highlights the potential risk of misidentification of herbs; in this case, D. purpurea was mistaken for S. officinale. Physicians should be aware that cardiac glycoside poisoning could arise from such misidentification. Public education about the toxicity of D. purpurea poisoning may reduce the risk of misidentification and subsequent poisoning.

  5. Antimicrobial lectin from Schinus terebinthifolius leaf.

    Science.gov (United States)

    Gomes, F S; Procópio, T F; Napoleão, T H; Coelho, L C B B; Paiva, P M G

    2013-03-01

    Schinus terebinthifolius leaves are used for treating human diseases caused by micro-organisms. This work reports the isolation, characterization and antimicrobial activity of S. terebinthifolius leaf lectin (SteLL). The isolation procedure involved protein extraction with 0.15 mol l(-1) NaCl, filtration through activated charcoal and chromatography of the filtrate on a chitin column. SteLL is a 14-kDa glycopeptide with haemagglutinating activity that is inhibited by N-acetyl-glucosamine, not affected by ions (Ca(2+) and Mg(2+)) and stable upon heating (30-100 °C) as well as over the pH 5.0-8.0. The antimicrobial effect of SteLL was evaluated by determining the minimal inhibitory (MIC), bactericide (MBC) and fungicide (MFC) concentrations. Lectin was active against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis and Staphylococcus aureus. Highest bacteriostatic and bactericide effects were detected for Salm. enteritidis (MIC: 0.45 μg ml(-1)) and Staph. aureus (MBC: 7.18 μg ml(-1)), respectively. SteLL impaired the growth (MIC: 6.5 μg ml(-1)) and survival (MFC: 26 μg ml(-1)) of Candida albicans. SteLL, a chitin-binding lectin, purified in milligram quantities, showed antimicrobial activity against medically important bacteria and fungi. SteLL can be considered as a new biomaterial for potential antimicrobial applications. © 2012 The Society for Applied Microbiology.

  6. An outbreak of foxglove leaf poisoning.

    Science.gov (United States)

    Lin, Chun-Chi; Yang, Chen-Chang; Phua, Dong-Haur; Deng, Jou-Fang; Lu, Li-Hua

    2010-02-01

    Comfrey (Symphytum officinale) leaves resemble those of foxglove (Digitalis purpurea) when the plant is not in bloom and, therefore, cardiac glycoside poisoning may occur when people confuse foxglove with comfrey. We report an outbreak of foxglove leaf poisoning following the use of alleged "comfrey" herbal tea. Nine patients were involved and initially presented with nausea, vomiting, diarrhea and dizziness. Significant cardiotoxicity developed later among the 3 patients who also had mild hyperkalemia. Peak serum digoxin concentration measured by immunoassay was elevated in all patients and ranged from 4.4 ng/mL to 139.5 ng/mL. Patients with severe cardiotoxicity were treated with temporary cardiac pacing. Moreover, 40-80 mg of digoxin-specific antibody therapy was given without any effect. All patients recovered uneventfully. Our report highlights the potential risk of misidentification of herbs; in this case, D. purpurea was mistaken for S. officinale. Physicians should be aware that cardiac glycoside poisoning could arise from such misidentification. Public education about the toxicity of D. purpurea poisoning may reduce the risk of misidentification and subsequent poisoning. Copyright 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

  7. The effect of glyphosate on import into a sink leaf of sugar beet

    International Nuclear Information System (INIS)

    Shieh, Wenjang; Geiger, D.R.

    1990-01-01

    The basis for glyphosate inducted limitation of carbon import into developing leaves was studied in sugar beet. To separate the effects of the herbicide on export from those on import, glyphosate was supplied to a developing leaf from two exporting source leaves which fed the sink leaf. Carbon import into the sink leaf was determined by supplying 14 CO 2 to a third source leaf which also supplies carbon to the monitored sink leaf. Import into the sink leaf decreased within 2 to 3 h after glyphosate application, even though photosynthesis and export in the source leaf supplying 14 C were unaffected. Reduced import into the sink leaf was accompanied by increased import by the tap root. Elongation of the sink leaf was only slightly decreased following arrival of glyphosate. Photosynthesis by the sink leaf was not inhibited. The results to data support the view that import is slowed by the inhibition of synthesis of structural or storage compounds in the developing leaves

  8. Analysis of leaf surfaces using scanning ion conductance microscopy.

    Science.gov (United States)

    Walker, Shaun C; Allen, Stephanie; Bell, Gordon; Roberts, Clive J

    2015-05-01

    Leaf surfaces are highly complex functional systems with well defined chemistry and structure dictating the barrier and transport properties of the leaf cuticle. It is a significant imaging challenge to analyse the very thin and often complex wax-like leaf cuticle morphology in their natural state. Scanning electron microscopy (SEM) and to a lesser extent Atomic force microscopy are techniques that have been used to study the leaf surface but their remains information that is difficult to obtain via these approaches. SEM is able to produce highly detailed and high-resolution images needed to study leaf structures at the submicron level. It typically operates in a vacuum or low pressure environment and as a consequence is generally unable to deal with the in situ analysis of dynamic surface events at submicron scales. Atomic force microscopy also possess the high-resolution imaging required and can follow dynamic events in ambient and liquid environments, but can over exaggerate small features and cannot image most leaf surfaces due to their inherent roughness at the micron scale. Scanning ion conductance microscopy (SICM), which operates in a liquid environment, provides a potential complementary analytical approach able to address these issues and which is yet to be explored for studying leaf surfaces. Here we illustrate the potential of SICM on various leaf surfaces and compare the data to SEM and atomic force microscopy images on the same samples. In achieving successful imaging we also show that SICM can be used to study the wetting of hydrophobic surfaces in situ. This has potentially wider implications than the study of leaves alone as surface wetting phenomena are important in a range of fundamental and applied studies. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  9. New Leaf Gilding Alloys: Physico-Chemistry, Colour, Mechanical Behavior

    OpenAIRE

    Darque-Ceretti , Evelyne; Aucouturier , Marc; Felder , Eric; Burr , Alain; Robcis , Dominique; Thomas , Caroline

    2015-01-01

    International audience; In the frame of a systematic investigation on leaf gilding history and processes, in a research program intending to propose gold leaf alloys specially devoted to restoration, new gold alloys containing low concentration additions of In or Pd were designed and leaves were elaborated in collaboration with the goldbeater Dauvet. The influence of those elements on the colour change induced by alloying was obtained by colorimetry. The microstructural and metallurgical prop...

  10. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    OpenAIRE

    Pervin, Mehnaz; Hasnat, Md Abul; Lim, Beong Ou

    2013-01-01

    Objective: To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum) . Methods: Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenolic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and t...

  11. Strigolactone Regulates Leaf Senescence in Concert with Ethylene in Arabidopsis.

    Science.gov (United States)

    Ueda, Hiroaki; Kusaba, Makoto

    2015-09-01

    Leaf senescence is not a passive degenerative process; it represents a process of nutrient relocation, in which materials are salvaged for growth at a later stage or to produce the next generation. Leaf senescence is regulated by various factors, such as darkness, stress, aging, and phytohormones. Strigolactone is a recently identified phytohormone, and it has multiple functions in plant development, including repression of branching. Although strigolactone is implicated in the regulation of leaf senescence, little is known about its molecular mechanism of action. In this study, strigolactone biosynthesis mutant strains of Arabidopsis (Arabidopsis thaliana) showed a delayed senescence phenotype during dark incubation. The strigolactone biosynthesis genes MORE AXIALLY GROWTH3 (MAX3) and MAX4 were drastically induced during dark incubation and treatment with the senescence-promoting phytohormone ethylene, suggesting that strigolactone is synthesized in the leaf during leaf senescence. This hypothesis was confirmed by a grafting experiment using max4 as the stock and Columbia-0 as the scion, in which the leaves from the Columbia-0 scion senesced earlier than max4 stock leaves. Dark incubation induced the synthesis of ethylene independent of strigolactone. Strigolactone biosynthesis mutants showed a delayed senescence phenotype during ethylene treatment in the light. Furthermore, leaf senescence was strongly accelerated by the application of strigolactone in the presence of ethylene and not by strigolactone alone. These observations suggest that strigolactone promotes leaf senescence by enhancing the action of ethylene. Thus, dark-induced senescence is regulated by a two-step mechanism: induction of ethylene synthesis and consequent induction of strigolactone synthesis in the leaf. © 2015 American Society of Plant Biologists. All Rights Reserved.

  12. Radioprotection of Swiss albino mice by Adhatoda vesica leaf extract

    International Nuclear Information System (INIS)

    Kumar, A.

    2003-01-01

    Full text: The radioprotective role of aqueous extract of Adhatoda vesica leaf extract against radiation induced hematological alterations in peripheral blood of Swiss albino mice was studied at various post-irradiation intervals between 6 hrs to 30 days. Oral administration of Adhatoda vesica leaf extract (800 mg / kg body weight) prior to whole-body irradiation showed a significant protection in terms of survival percentage and hematological parameters. Mice exposed to radiation (8 Gy) without Adhatoda vesica leaf extract pre-treatment exhibited signs of radiation sickness like anorexia, lethargicity, ruffled hairs and diarrhoea and such animals died within 26 days post-irradiation. The dose reduction factor (DRF=1.6) for Adhatoda vesica leaf extract was calculated from LD50/30 values. A significant decline in hematological constituents (RBCs, WBCs, Hb and Hct) was evident till day 15, at later period of observation (day 15 onwards), no animals could survive from control group whereas, in Adhatoda vesica leaf extract pre-treated irradiated group, a gradual recovery was noted in the hematological values. However, these hematological values remained significantly below the normal even till day 30. A significant decrease in GSH was recorded in control animals. Experimental animals showed a significant increase in GSH content (blood as well as liver) with respect to control, but such values remained below normal. A significant increase in TBARS level in liver and serum was evident in control animals. Although, no significant difference was noticed in such levels in normal and Adhatoda vesica leaf extract treated animals. But, a significant decrease was registered in Adhatoda vesica leaf extract pretreated irradiated animals. The results from the present study suggest that Adhatoda vesica leaf extract has radioprotective role in stimulating/protecting the hematopoietic system thereby enhancing the survival and increasing the hematological constituents in peripheral

  13. Optimal allocation of leaf epidermal area for gas exchange

    OpenAIRE

    de Boer, Hugo J.; Price, Charles A.; Wagner-Cremer, Friederike; Dekker, Stefan C.; Franks, Peter J.; Veneklaas, Erik J.

    2016-01-01

    Summary A long?standing research focus in phytology has been to understand how plants allocate leaf epidermal space to stomata in order to achieve an economic balance between the plant's carbon needs and water use. Here, we present a quantitative theoretical framework to predict allometric relationships between morphological stomatal traits in relation to leaf gas exchange and the required allocation of epidermal area to stomata. Our theoretical framework was derived from first principles of ...

  14. BIOMONITORING OF URBAN AREA BY ANATOMICAL LEAF CHANGES

    Directory of Open Access Journals (Sweden)

    Elena IRIZA

    2012-01-01

    Full Text Available Plants play a vital role as indicators of pollution. The automobile emissions are high particularly at the traffic intersections. Plants growing under the stress of air pollution show differences in leaf surface characteristics. Light microscopic studies of leaf surface revealed an increase in the number of stomata and trichomes of polluted populations in comparison to control populations of Plantago major and Plantago lanceolata. These changes can be considered as indicators of environmental stress.

  15. Antimicrobial activity of medicinal plant leaf extracts against pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Atikya Farjana

    2014-09-01

    Full Text Available Objective: To determine antibacterial activity of water, oil and methanol extracts of guava (Psidium guajava, green tea (Camellia sinensis, neem (Azadirachta indica and marigold (Calendula officinalis against different species of bacteria, Pseudomonas spp., Vibrio cholerae, Vibrio parahaemolyticus (V. parahaemolyticus, Klebsiella spp., Escherichia coli, Salmonella spp. and Staphylococcus aureus (S. aureus. Methods: Antibacterial activity of plant extracts was measured by agar well diffusion method. Results: Boiled water extracts of guava leaf showed the largest zone of inhibition (22 mm against V. parahaemolyticus. Water extracts of green tea leaf at boiling and room temperature showed 17.5 mm and 19 mm zone of inhibitions against V. parahaemolyticus and S. aureus, respectively. Boiled water extract of neem leaf showed moderate zone of inhibition against Escherichia coli (10 mm and Klebsiella spp. (11 mm. Water and oil extracts of marigold leaf at both boiling and room temperature did not show any zone of inhibition against any of the tested microorganisms. Methanol extracts of both guava and green tea leaves showed same zone of inhibition against Pseudomonus spp. (18 mm. Methanol extract of neem leaf showed antibacterial acitivity against Klebsiella spp. (16 mm and Vibrio cholerae (14 mm and that of marigold leaf showed antimicrobial activity against S. aureus (18 mm and Klebsiella spp. (12 mm. Conclusions: The results from the study suggest that the leaves of guava, green tea, neem and marigold show anibacterial activity against different bacterial species. They could be used as alternatives to common antimicrobial agents for treatment of bacterial infections.

  16. Consequences of leaf calibration errors on IMRT delivery

    International Nuclear Information System (INIS)

    Sastre-Padro, M; Welleweerd, J; Malinen, E; Eilertsen, K; Olsen, D R; Heide, U A van der

    2007-01-01

    IMRT treatments using multi-leaf collimators may involve a large number of segments in order to spare the organs at risk. When a large proportion of these segments are small, leaf positioning errors may become relevant and have therapeutic consequences. The performance of four head and neck IMRT treatments under eight different cases of leaf positioning errors has been studied. Systematic leaf pair offset errors in the range of ±2.0 mm were introduced, thus modifying the segment sizes of the original IMRT plans. Thirty-six films were irradiated with the original and modified segments. The dose difference and the gamma index (with 2%/2 mm criteria) were used for evaluating the discrepancies between the irradiated films. The median dose differences were linearly related to the simulated leaf pair errors. In the worst case, a 2.0 mm error generated a median dose difference of 1.5%. Following the gamma analysis, two out of the 32 modified plans were not acceptable. In conclusion, small systematic leaf bank positioning errors have a measurable impact on the delivered dose and may have consequences for the therapeutic outcome of IMRT

  17. Butterfly Learning and the Diversification of Plant Leaf Shape

    Directory of Open Access Journals (Sweden)

    Denise Dalbosco Dell'aglio

    2016-07-01

    Full Text Available Visual cues are important for insects to find flowers and host plants. It has been proposed that the diversity of leaf shape in Passiflora vines could be a result of negative frequency dependent selection driven by visual searching behavior among their butterfly herbivores. Here we tested the hypothesis that Heliconius butterflies use leaf shape as a cue to initiate approach towards a host plant. We first tested for the ability to recognize shapes using a food reward conditioning experiment. Butterflies showed an innate preference for flowers with three and five petals. However, they could be trained to increase the frequency of visits to a non-preferred flower with two petals, indicating an ability to learn to associate shape with a reward. Next we investigated shape learning specifically in the context of oviposition by conditioning females to lay eggs on two shoots associated with different artificial leaf shapes: their own host plant, Passiflora biflora, and a lanceolate non-biflora leaf shape. The conditioning treatment had a significant effect on the approach of butterflies to the two leaf shapes, consistent with a role for shape learning in oviposition behavior. This study is the first to show that Heliconius butterflies use shape as a cue for feeding and oviposition, and can learn shape preference for both flowers and leaves. This demonstrates the potential for Heliconius to drive negative frequency dependent selection on the leaf shape of their Passiflora host plants.

  18. The leaf phenophase of deciduous species altered by land pavements

    Science.gov (United States)

    Chen, Yuanyuan; Wang, Xiaoke; Jiang, Bo; Li, Li

    2018-02-01

    It has been widely reported that the urban environment alters leaf and flowering phenophases; however, it remains unclear if land pavement is correlated with these alterations. In this paper, two popular deciduous urban trees in northern China, ash (Fraxinus chinensis) and maple (Acer truncatum), were planted in pervious and impervious pavements at three spacings (0.5 m × 0.5 m, 1.0 m × 1.0 m, and 2.0 m × 2.0 m apart). The beginning and end dates of the processes of leaf budburst and senescence were recorded in spring and fall of 2015, respectively. The results show that leaf budburst and senescence were significantly advanced in pavement compared to non-pavement lands. The date of full leaf budburst was earlier by 0.7-9.3 days for ash and by 0.3-2.3 days for maple under pavements than non-pavements, respectively. As tree spacing increases, the advanced days of leaf budburst became longer. Our results clearly indicate that alteration of leaf phenophases is attributed to land pavement, which should be taken into consideration in urban planning and urban plant management.

  19. A finger leaf design for dual layer MLCs

    International Nuclear Information System (INIS)

    Cui Weijie; Dai Jianrong

    2010-01-01

    Objective: To introduce a finger leaf design that is applied to dual layer MLCs. Methods: An optimization model was firstly constructed to describe the problem of determining leaf end shapes,and the corresponding problems were then solved by the simplex search method or the simulated annealing technique. Optimal parameters for arc shapes of leaf end projections were obtained, and a comparison was done between optimized MLCs and conventional MLCs in terms of field conformity. The optimization process was based on 634 target fields selected from the patient data base of a treatment planning system. Areas of these fields ranged from 20.0 to 602.7 cm with a mean and its standard deviation of (125.7 ± 0.0) cm 2 . Results: The optimized leaf end shapes projected to the isocenter plane were semicircles. With the finger leaf design, the total area of discrepancy regions between MLC fields and target fields was reduced by 32.3%. Conclusions: The finger leaf design improves the conformity of the MLC shaped fields to the desired target fields. (authors)

  20. Estimating leaf functional traits by inversion of PROSPECT: Assessing leaf dry matter content and specific leaf area in mixed mountainous forest

    Science.gov (United States)

    Ali, Abebe Mohammed; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Duren, Iris van; Heiden, Uta; Heurich, Marco

    2016-03-01

    Assessments of ecosystem functioning rely heavily on quantification of vegetation properties. The search is on for methods that produce reliable and accurate baseline information on plant functional traits. In this study, the inversion of the PROSPECT radiative transfer model was used to estimate two functional leaf traits: leaf dry matter content (LDMC) and specific leaf area (SLA). Inversion of PROSPECT usually aims at quantifying its direct input parameters. This is the first time the technique has been used to indirectly model LDMC and SLA. Biophysical parameters of 137 leaf samples were measured in July 2013 in the Bavarian Forest National Park, Germany. Spectra of the leaf samples were measured using an ASD FieldSpec3 equipped with an integrating sphere. PROSPECT was inverted using a look-up table (LUT) approach. The LUTs were generated with and without using prior information. The effect of incorporating prior information on the retrieval accuracy was studied before and after stratifying the samples into broadleaf and conifer categories. The estimated values were evaluated using R2 and normalized root mean square error (nRMSE). Among the retrieved variables the lowest nRMSE (0.0899) was observed for LDMC. For both traits higher R2 values (0.83 for LDMC and 0.89 for SLA) were discovered in the pooled samples. The use of prior information improved accuracy of the retrieved traits. The strong correlation between the estimated traits and the NIR/SWIR region of the electromagnetic spectrum suggests that these leaf traits could be assessed at canopy level by using remotely sensed data.

  1. Seasonal patterns of leaf gas exchange and water relations in dry rain forest trees of contrasting leaf phenology.

    Science.gov (United States)

    Choat, Brendan; Ball, Marilyn C; Luly, Jon G; Donnelly, Christine F; Holtum, Joseph A M

    2006-05-01

    Diurnal and seasonal patterns of leaf gas exchange and water relations were examined in tree species of contrasting leaf phenology growing in a seasonally dry tropical rain forest in north-eastern Australia. Two drought-deciduous species, Brachychiton australis (Schott and Endl.) A. Terracc. and Cochlospermum gillivraei Benth., and two evergreen species, Alphitonia excelsa (Fenzal) Benth. and Austromyrtus bidwillii (Benth.) Burret. were studied. The deciduous species had higher specific leaf areas and maximum photosynthetic rates per leaf dry mass in the wet season than the evergreens. During the transition from wet season to dry season, total canopy area was reduced by 70-90% in the deciduous species and stomatal conductance (g(s)) and assimilation rate (A) were markedly lower in the remaining leaves. Deciduous species maintained daytime leaf water potentials (Psi(L)) at close to or above wet season values by a combination of stomatal regulation and reduction in leaf area. Thus, the timing of leaf drop in deciduous species was not associated with large negative values of daytime Psi(L) (greater than -1.6 MPa) or predawn Psi(L) (greater than -1.0 MPa). The deciduous species appeared sensitive to small perturbations in soil and leaf water status that signalled the onset of drought. The evergreen species were less sensitive to the onset of drought and g(s) values were not significantly lower during the transitional period. In the dry season, the evergreen species maintained their canopies despite increasing water-stress; however, unlike Eucalyptus species from northern Australian savannas, A and g(s) were significantly lower than wet season values.

  2. Antibacterial activity, chemical composition, and cytotoxicity of leaf?s essential oil from brazilian pepper tree (schinus terebinthifolius, raddi)

    OpenAIRE

    Silva, A.B.; Silva, T.; Franco, E.S.; Rabelo, S.A.; Lima, E.R.; Mota, R.A.; da C?mara, C.A.G.; Pontes-Filho, N.T.; Lima-Filho, J.V.

    2010-01-01

    The antibacterial potential of leaf?s essential oil (EO) from Brazilian pepper tree (Schinus terebinthifolius Raddi) against staphylococcal isolates from dogs with otitis externa was evaluated. The minimum inhibitory concentration of EO ranged from 78.1 to 1,250 ?g/mL. The oil was analyzed by GC and GC/MS and cytotoxicity tests were carried out with laboratory animals.

  3. The YABBY Genes of Leaf and Leaf-Like Organ Polarity in Leafless Plant Monotropa hypopitys

    Directory of Open Access Journals (Sweden)

    Anna V. Shchennikova

    2018-01-01

    Full Text Available Monotropa hypopitys is a mycoheterotrophic, nonphotosynthetic plant acquiring nutrients from the roots of autotrophic trees through mycorrhizal symbiosis, and, similar to other extant plants, forming asymmetrical lateral organs during development. The members of the YABBY family of transcription factors are important players in the establishment of leaf and leaf-like organ polarity in plants. This is the first report on the identification of YABBY genes in a mycoheterotrophic plant devoid of aboveground vegetative organs. Seven M. hypopitys YABBY members were identified and classified into four clades. By structural analysis of putative encoded proteins, we confirmed the presence of YABBY-defining conserved domains and identified novel clade-specific motifs. Transcriptomic and qRT-PCR analyses of different tissues revealed MhyYABBY transcriptional patterns, which were similar to those of orthologous YABBY genes from other angiosperms. These data should contribute to the understanding of the role of the YABBY genes in the regulation of developmental and physiological processes in achlorophyllous leafless plants.

  4. Screening Study of Leaf Terpene Concentration of 75 Borneo Rainforest Plant Species: Relationships with Leaf Elemental Concentrations and Morphology

    Directory of Open Access Journals (Sweden)

    Jordi Sardans

    2015-01-01

    Full Text Available Terpenes confer advantage in plant protection against abiotic stresses such as heat and drought and biotic stresses such as herbivore and pathogen attack. We conducted a screening of leaf mono- and sesquiterpene concentrations in 75 common woody plant species in the rainforest of Danum Valley (Borneo. Terpene compounds were found in 73 out of the 75 analysed species. Similar or lower proportions have been reported in other parts of the world. To our knowledge, this study reports for the first time the foliar concentration of mono- and/or sesquiterpene for 71 species and 39 genera not previously analyzed. Altogether 80 terpene compounds were determined across the species, and out of these only linalool oxide and (E- g -bisabolene had phylogenetic signal. A significant negative relationship between leaf monoterpene concentration and leaf length was observed, but leaf mono- and sesquitepene concentration were not related to any other leaf morphological trait nor to leaf elemental composition. Functions such as temperature protection, radiation protection or signaling and communication could underlie the high frequency of terpene-containing species of this tropical ecosystem which has multiple and very diverse interactions among multiple species.

  5. Foraging on individual leaves by an intracellular feeding insect is not associated with leaf biomechanical properties or leaf orientation.

    Directory of Open Access Journals (Sweden)

    Justin Fiene

    Full Text Available Nearly all herbivorous arthropods make foraging-decisions on individual leaves, yet systematic investigations of the adaptive significance and ecological factors structuring these decisions are rare with most attention given to chewing herbivores. This study investigated why an intracellular feeding herbivore, Western flower thrips (WFT Frankliniella occidentalis Pergande, generally avoids feeding on the adaxial leaf surface of cotton cotyledons. WFT showed a significant aversion to adaxial-feeding even when excised-cotyledons were turned up-side (abaxial-side 'up', suggesting that negative-phototaxis was not a primary cause of thrips foraging patterns. No-choice bioassays in which individual WFT females were confined to either the abaxial or adaxial leaf surface showed that 35% fewer offspring were produced when only adaxial feeding was allowed, which coincided with 32% less plant feeding on that surface. To test the hypothesis that leaf biomechanical properties inhibited thrips feeding on the adaxial surface, we used a penetrometer to measure two variables related to the 'toughness' of each leaf surface. Neither variable negatively co-varied with feeding. Thus, while avoiding the upper leaf surface was an adaptive foraging strategy, the proximate cause remains to be elucidated, but is likely due, in part, to certain leaf properties that inhibit feeding.

  6. Patterns of leaf morphology and leaf N content in relation to winter temperatures in three evergreen tree species

    Science.gov (United States)

    Mediavilla, Sonia; Gallardo-López, Victoria; González-Zurdo, Patricia; Escudero, Alfonso

    2012-09-01

    The competitive equilibrium between deciduous and perennial species in a new scenario of climate change may depend closely on the productivity of leaves along the different seasons of the year and on the morphological and chemical adaptations required for leaf survival during the different seasons. The aim of the present work was to analyze such adaptations in the leaves of three evergreen species ( Quercus ilex, Q. suber and Pinus pinaster) and their responses to between-site differences in the intensity of winter harshness. We explore the hypothesis that the harshness of winter would contribute to enhancing the leaf traits that allow them to persist under conditions of stress. The results revealed that as winter harshness increases a decrease in leaf size occurs in all three species, together with an increase in the content of nitrogen per unit leaf area and a greater leaf mass per unit area, which seems to be achieved only through increased thickness, with no associated changes in density. P. pinaster was the species with the most intense response to the harshening of winter conditions, undergoing a more marked thickening of its needles than the two Quercus species. Our findings thus suggest that lower winter temperatures involve an increase in the cost of leaf production of evergreen species, which must be taken into account in the estimation of the final cost and benefit balance of evergreens. Such cost increases would be more pronounced for those species that, like P. pinaster, show a stronger response to the winter cold.

  7. Ozone induced leaf loss and decreased leaf production of European Holly (Ilex aquifolium L.) over multiple seasons

    International Nuclear Information System (INIS)

    Ranford, Jonathan; Reiling, Kevin

    2007-01-01

    European Holly (Ilex aquifolium L.) was used to study the impact of one short (28 day) ozone fumigation episode on leaf production, leaf loss and stomatal conductance (g s ), in order to explore potential longer term effects over 3 growing seasons. Young I. aquifolium plants received an episode of either charcoal-filtered air or charcoal-filtered air with 70 nl l -1 O 3 added for 7 h d -1 over a 28 day period from June 15th 1996, then placed into ambient environment, Stoke-on-Trent, U.K. Data were collected per leaf cohort over the next three growing seasons. Ozone exposure significantly increased leaf loss and stomatal conductance and reduced leaf production over all subsequent seasons. Impact of the initial ozone stress was still detected in leaves that had no direct experimental ozone exposure. This study has shown the potential of ozone to introduce long-term phenological perturbations into ecosystems by influencing productivity over a number of seasons. - Ozone significantly alters Ilex aquifolium leaf production and loss over multiple seasons

  8. Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

    Science.gov (United States)

    Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

    2013-01-01

    Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

  9. Titan Lifting Entry & Atmospheric Flight (T-LEAF) Science Mission

    Science.gov (United States)

    Lee, G.; Sen, B.; Ross, F.; Sokol, D.

    2016-12-01

    Northrop Grumman has been developing the Titan Lifting Entry & Atmospheric Flight (T-LEAF) sky rover to roam the lower atmosphere and observe at close quarters the lakes and plains of Saturn's ocean moon, Titan. T-LEAF also supports surface exploration and science by providing precision delivery of in-situ instruments to the surface of Titan. T-LEAF is a highly maneuverable sky rover and its aerodynamic shape (i.e., a flying wing) does not restrict it to following prevailing wind patterns on Titan, but allows mission operators to chart its course. This freedom of mobility allows T-LEAF to follow the shorelines of Titan's methane lakes, for example, or to target very specific surface locations. We will present a straw man concept of T-LEAF, including size, mass, power, on-board science payloads and measurement, and surface science dropsonde deployment CONOPS. We will discuss the various science instruments and their vehicle level impacts, such as meteorological and electric field sensors, acoustic sensors for measuring shallow depths, multi-spectral imagers, high definition cameras and surface science dropsondes. The stability of T-LEAF and its long residence time on Titan will provide for time to perform a large aerial survey of select prime surface targets deployment of dropsondes at selected locations surface measurements that are coordinated with on-board remote measurements communication relay capabilities to orbiter (or Earth). In this context, we will specifically focus upon key factors impacting the design and performance of T-LEAF science: science payload accommodation, constraints and opportunities characteristics of flight, payload deployment and measurement CONOPS in the Titan atmosphere. This presentation will show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of Titan's surface.

  10. The new electric powertrain on the 2013 MY Nissan LEAF

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Naoki; Nakazawa, Shinsuke [Nissan Motor Co., Ltd. (Japan)

    2013-08-01

    The Nissan LEAF was launched in 2010 as the world's first mass-produced electric vehicle. Among its many honours received to date, the Nissan LEAF won the 2011 European Car of the Year (COTY) award, the 2011 World COTY award, the 2011-2012 Japan COTY award and was named in Ward's 10 Best Engines list for 2011, which attest to its high market acclaim. As of 2012, over 46,000 units of the Nissan LEAF are now on the road in some 33 countries worldwide, especially in Japan, the U.S. and Europe. The 2013 model year Nissan LEAF has been announced and released, featuring substantial improvements in all-around performance based on a thoroughgoing analysis of the driving data recorded by the Nissan LEAF in real-world use during the past two years. One of the major changes made to the 2013 model is the adoption of an all-new electric powertrain. The traction motor, inverter and charging unit of this new electric powertrain have all been fully redesigned. Moreover, these high-voltage parts specific to an EV are now assembled into an integrated powertrain that is 30% smaller, 10% lighter and significantly less expensive than the corresponding electric powertrain used on the 2011 model. The driving range of the 2013 Nissan LEAF has also been extended by more than 10% over that of the 2011 model as a result of adopting an improved cooperative regenerative braking system and a heat pump-based air-conditioning system, lightening the vehicle weight, lowering the drag coefficient, and reducing the parasitic loads of the auxiliary units. In addition, the human-machine interface elements, including the navigation system and the instruments have also been improved to enhance the convenience of driving an EV. This paper describes various key technologies featured on the 2013 Nissan LEAF, focusing in particular on the newly developed electric powertrain. (orig.)

  11. Dynamics of vacuum-sealed, double-leaf partitions

    Science.gov (United States)

    Kavanaugh, Joshua Stephen

    The goal of this research is to investigate the feasibility and potential effectiveness of using vacuum-sealed, double-leaf partitions for applications in noise control. Substantial work has been done previously on double-leaf partitions where the acoustics of the inner chamber and mechanical vibrations of structural supports are passively and actively controlled. The work presented here is unique in that the proposed system aims to eliminate the need for active acoustic control of transmitted acoustic energy by removing all the air between the two panels of the double partition. Therefore, the only remaining energy paths would be along the boundary and at the points where there are intermediate structural supports connecting the two panels. The eventual goal of the research is to develop a high-loss double-leaf partition that simplifies active control by removing the need for control of the air cavity and channeling all the energy into discrete structural paths. The work presented here is a first step towards the goal of designing a high-loss, actively-controlled double-leaf partition with an air-evacuated inner chamber. One experiment is conducted to investigate the effects of various levels of vacuum on the response of a double-leaf partition whose panels are mechanically coupled only at the boundary. Another experiment is conducted which investigates the effect of changing the stiffness of an intermediate support coupling the two panels of a double-leaf partition in which a vacuum has been applied to the inner cavity. The available equipment was able to maintain a 99% vacuum between the panels. Both experiments are accompanied by analytical models used to investigate the importance of various dynamic parameters. Results show that the vacuum-sealed system shows some potential for increased transmission loss, primarily by the changing the natural frequencies of the double-leaf partition.

  12. Cotton leaf curl Burewala virus with intact or mutant transcriptional activator proteins: complexity of cotton leaf curl disease.

    Science.gov (United States)

    Kumar, Jitendra; Gunapati, Samatha; Alok, Anshu; Lalit, Adarsh; Gadre, Rekha; Sharma, Naresh C; Roy, Joy K; Singh, Sudhir P

    2015-05-01

    Cotton leaf curl disease (CLCuD) is a serious disease of cotton on the Indian subcontinent. In the present study, three cotton leaf curl viruses, cotton leaf curl Burewala virus (CLCuBuV), cotton leaf curl Kokhran virus (CLCuKoV) and cotton leaf curl Multan virus (CLCuMV), and their associated satellites, cotton leaf curl Multan betasatellite (CLCuMB) and cotton leaf curl Multan alphasatellite (CLCuMA), were detected. CLCuBuV with either intact (CLCuBuV-1) or mutant (CLCuBuV-2) transcriptional activator protein (TrAP) were detected in different plants. Agroinoculation with CLCuBuV-1 or CLCuBuV-2 together with CLCuMB and CLCuMA, resulted in typical leaf curling and stunting of tobacco plants. Inoculation with CLCuKoV or an isolate of CLCuMV (CLCuMV-2), together with CLCuMB and CLCuMA, induced severe leaf curling, while the other isolate of CLCuMV (CLCuMV-1), which was recombinant in origin, showed mild leaf curling in tobacco. To investigate the effect of intact or mutant TrAP and also the recombination events, CLCuBuV-1, CLCuBuV-2, CLCuMV-1 or CLCuMV-2 together with the satellites (CLCuMA and CLCuMB) were transferred to cotton via whitefly-mediated transmission. Cotton plants containing CLCuBuV-1, CLCuBuV-2 or CLCuMV-2 together with satellites showed curling and stunting, whereas the plants having CLCuMV-1 and the satellites showed only mild and indistinguishable symptoms. CLCuBuV-1 (intact TrAP) showed severe symptoms in comparison to CLCuBuV-2 (mutant TrAP). The present study reveals that two types of CLCuBuV, one with an intact TrAP and the other with a mutant TrAP, exist in natural infection of cotton in India. Additionally, CLCuMuV-1, which has a recombinant origin, induces mild symptoms in comparison to the other CLCuMV isolates.

  13. Photoperiod-H1 (Ppd-H1) Controls Leaf Size1[OPEN

    Science.gov (United States)

    Digel, Benedikt; Tavakol, Elahe; Verderio, Gabriele; Xu, Xin

    2016-01-01

    Leaf size is a major determinant of plant photosynthetic activity and biomass; however, it is poorly understood how leaf size is genetically controlled in cereal crop plants like barley (Hordeum vulgare). We conducted a genome-wide association scan for flowering time, leaf width, and leaf length in a diverse panel of European winter cultivars grown in the field and genotyped with a single-nucleotide polymorphism array. The genome-wide association scan identified PHOTOPERIOD-H1 (Ppd-H1) as a candidate gene underlying the major quantitative trait loci for flowering time and leaf size in the barley population. Microscopic phenotyping of three independent introgression lines confirmed the effect of Ppd-H1 on leaf size. Differences in the duration of leaf growth and consequent variation in leaf cell number were responsible for the leaf size differences between the Ppd-H1 variants. The Ppd-H1-dependent induction of the BARLEY MADS BOX genes BM3 and BM8 in the leaf correlated with reductions in leaf size and leaf number. Our results indicate that leaf size is controlled by the Ppd-H1- and photoperiod-dependent progression of plant development. The coordination of leaf growth with flowering may be part of a reproductive strategy to optimize resource allocation to the developing inflorescences and seeds. PMID:27457126

  14. Photoperiod-H1 (Ppd-H1) Controls Leaf Size.

    Science.gov (United States)

    Digel, Benedikt; Tavakol, Elahe; Verderio, Gabriele; Tondelli, Alessandro; Xu, Xin; Cattivelli, Luigi; Rossini, Laura; von Korff, Maria

    2016-09-01

    Leaf size is a major determinant of plant photosynthetic activity and biomass; however, it is poorly understood how leaf size is genetically controlled in cereal crop plants like barley (Hordeum vulgare). We conducted a genome-wide association scan for flowering time, leaf width, and leaf length in a diverse panel of European winter cultivars grown in the field and genotyped with a single-nucleotide polymorphism array. The genome-wide association scan identified PHOTOPERIOD-H1 (Ppd-H1) as a candidate gene underlying the major quantitative trait loci for flowering time and leaf size in the barley population. Microscopic phenotyping of three independent introgression lines confirmed the effect of Ppd-H1 on leaf size. Differences in the duration of leaf growth and consequent variation in leaf cell number were responsible for the leaf size differences between the Ppd-H1 variants. The Ppd-H1-dependent induction of the BARLEY MADS BOX genes BM3 and BM8 in the leaf correlated with reductions in leaf size and leaf number. Our results indicate that leaf size is controlled by the Ppd-H1- and photoperiod-dependent progression of plant development. The coordination of leaf growth with flowering may be part of a reproductive strategy to optimize resource allocation to the developing inflorescences and seeds. © 2016 American Society of Plant Biologists. All rights reserved.

  15. Peach leaf responses to soil and cement dust pollution.

    Science.gov (United States)

    Maletsika, Persefoni A; Nanos, George D; Stavroulakis, George G

    2015-10-01

    Dust pollution can negatively affect plant productivity in hot, dry and with high irradiance areas during summer. Soil or cement dust were applied on peach trees growing in a Mediterranean area with the above climatic characteristics. Soil and cement dust accumulation onto the leaves decreased the photosynthetically active radiation (PAR) available to the leaves without causing any shade effect. Soil and mainly cement dust deposition onto the leaves decreased stomatal conductance, photosynthetic and transpiration rates, and water use efficiency due possibly to stomatal blockage and other leaf cellular effects. In early autumn, rain events removed soil dust and leaf functions partly recovered, while cement dust created a crust partially remaining onto the leaves and causing more permanent stress. Leaf characteristics were differentially affected by the two dusts studied due to their different hydraulic properties. Leaf total chlorophyll decreased and total phenol content increased with dust accumulation late in the summer compared to control leaves due to intense oxidative stress. The two dusts did not cause serious metal imbalances to the leaves, except of lower leaf K content.

  16. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Directory of Open Access Journals (Sweden)

    Mehnaz Pervin

    2013-12-01

    Full Text Available Objective: To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum . Methods: Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenolic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx, metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion method against seven strains of bacteria. Results: Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone at 10 mg/ disc. The IC 50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions: These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  17. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Science.gov (United States)

    Pervin, Mehnaz; Hasnat, Md Abul; Lim, Beong Ou

    2013-01-01

    Objective To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum). Methods Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenoic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion for seven strains of bacteria. Results Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone) against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone) at 10 mg/ disc. The IC50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  18. Leaf area estimation of cassava from linear dimensions

    Directory of Open Access Journals (Sweden)

    SAMARA ZANETTI

    2017-08-01

    Full Text Available ABSTRACT The objective of this study was to determine predictor models of leaf area of cassava from linear leaf measurements. The experiment was carried out in greenhouse in the municipality of Botucatu, São Paulo state, Brazil. The stem cuttings with 5-7 nodes of the cultivar IAC 576-70 were planted in boxes filled with about 320 liters of soil, keeping soil moisture at field capacity, monitored by puncturing tensiometers. At 80 days after planting, 140 leaves were randomly collected from the top, middle third and base of cassava plants. We evaluated the length and width of the central lobe of leaves, number of lobes and leaf area. The measurements of leaf areas were correlated with the length and width of the central lobe and the number of lobes of the leaves, and adjusted to polynomial and multiple regression models. The linear function that used the length of the central lobe LA = -69.91114 + 15.06462L and linear multiple functions LA = -69.9188 + 15.5102L + 0.0197726K - 0.0768998J or LA = -69.9346 + 15.0106L + 0.188931K - 0.0264323H are suitable models to estimate leaf area of cassava cultivar IAC 576-70.

  19. Climate controls photosynthetic capacity more than leaf nitrogen contents

    Science.gov (United States)

    Ali, A. A.; Xu, C.; McDowell, N. G.

    2013-12-01

    Global vegetation models continue to lack the ability to make reliable predictions because the photosynthetic capacity varies a lot with growth conditions, season and among species. It is likely that vegetation models link photosynthetic capacity to concurrent changes in leaf nitrogen content only. To improve the predictions of the vegetation models, there is an urgent need to review species growth conditions and their seasonal response to changing climate. We sampled the global distribution of the Vcmax (maximum carboxylation rates) data of various species across different environmental gradients from the literature and standardized its value to 25 degree Celcius. We found that species explained the largest variation in (1) the photosynthetic capacity and (2) the proportion of nitrogen allocated for rubisco (PNcb). Surprisingly, climate variables explained more variations in photosynthetic capacity as well as PNcb than leaf nitrogen content and/or specific leaf area. The chief climate variables that explain variation in photosynthesis and PNcb were radiation, temperature and daylength. Our analysis suggests that species have the greatest control over photosynthesis and PNcb. Further, compared to leaf nitrogen content and/or specific leaf area, climate variables have more control over photosynthesis and PNcb. Therefore, climate variables should be incorporated in the global vegetation models when making predictions about the photosynthetic capacity.

  20. Gamma irradiation enhances biological activities of mulberry leaf extract

    International Nuclear Information System (INIS)

    Cho, Byoung-Ok; Che, Denis Nchang; Yin, Hong-Hua; Jang, Seon-Il

    2017-01-01

    The purpose of this study was to investigate the influence of irradiation on the anti-oxidative, anti-inflammatory and whitening effects of mulberry leaf extract. This was done by comparing the phenolic contents; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects; 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging effects; in vitro tyrosinase inhibitory effects and the production of IL-6, TNF-α, PGE 2 , and NO in lipopolysaccharide-stimulated RAW264.7 macrophages and the production of IL-6 and TNF-α in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 cells, respectively. The results showed that irradiated mulberry leaf extract possesses more anti-oxidant, anti-inflammatory, and tyrosinase inhibitory activities than their non-irradiated counterpart, probably due to increase in phenolic contents induced by gamma irradiation at dose of 10kGy. This research stresses on the importance of irradiation in functional foods. - Highlights: • Gamma-irradiated mulberry leaf extract enhanced in vitro antioxidant activities. • Gamma-irradiated mulberry leaf extract enhanced in vitro tyrosinase inhibitory effects. • Gamma-irradiated mulberry leaf extract treatment reduced the production of IL-6, TNF-α, PGE 2 , and NO.

  1. Macroecological and macroevolutionary patterns of leaf herbivory across vascular plants.

    Science.gov (United States)

    Turcotte, Martin M; Davies, T Jonathan; Thomsen, Christina J M; Johnson, Marc T J

    2014-07-22

    The consumption of plants by animals underlies important evolutionary and ecological processes in nature. Arthropod herbivory evolved approximately 415 Ma and the ensuing coevolution between plants and herbivores is credited with generating much of the macroscopic diversity on the Earth. In contemporary ecosystems, herbivory provides the major conduit of energy from primary producers to consumers. Here, we show that when averaged across all major lineages of vascular plants, herbivores consume 5.3% of the leaf tissue produced annually by plants, whereas previous estimates are up to 3.8× higher. This result suggests that for many plant species, leaf herbivory may play a smaller role in energy and nutrient flow than currently thought. Comparative analyses of a diverse global sample of 1058 species across 2085 populations reveal that models of stabilizing selection best describe rates of leaf consumption, and that rates vary substantially within and among major plant lineages. A key determinant of this variation is plant growth form, where woody plant species experience 64% higher leaf herbivory than non-woody plants. Higher leaf herbivory in woody species supports a key prediction of the plant apparency theory. Our study provides insight into how a long history of coevolution has shaped the ecological and evolutionary relationships between plants and herbivores. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  2. Penumbra measurements of BeamModulatorTM multi leaf collimator

    International Nuclear Information System (INIS)

    Lu Xiaoguang; Wang Yunlai; Huo Xiaoqing; Sha Xiangyan; Miao Xiongfei

    2010-01-01

    Objective: To evaluate the penumbra of a new multileaf collimator equipped with Elekta Synergy accelerator. Methods: The penumbra were derived from beam profiles measured in air and water using PinPoint ion chamber with PTW MP3 water phantom. Variations of penumbra with X-ray beam energy, depth in water, and leaf position were investigated. Results: The penumbra in air for 6 MV X-ray was 2 mm less than that at depth of maximal dose in water. The penumbra of leaf side was 1 mm less than that of the leaf end. The penumbra had close relationship with beam energy, depth in water and leaf position. penumbra increased with beam quality and water depth. The leaf position had great influence on the penumbra. Conclusions: The penumbra of the multileaf collimator is related to its original design and radiation delivery technique. Special considerations should be taken into during treatment planning. Regular measurement should be performed to guarantee the delivery quality. (authors)

  3. Leaf micromorphology of some Phyllanthus L. species (Phyllanthaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Solihani, N. S., E-mail: noorsolihani@gmail.com; Noraini, T., E-mail: norainitalip@gmail.com [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Azahana, A., E-mail: bell-azahana@yahoo.com [Department of Plant Science, Kulliyyah of Science, International Islamic University Malaysia, Kuantan Campus, Kuantan, Pahang (Malaysia); Nordahlia, A. S., E-mail: nordahlia@frim.gov.my [Forest Research Institute of Malaysia, 52109 Kepong, Selangor (Malaysia)

    2015-09-25

    Comparative leaf micromorphological study was conducted of five chosen Phyllanthus L. (Phyllanthaceae) species, namely P. acidus L., P. elegans Wall. ex Müll. Arg., P. emblica L., P. urinaria L. and P. pulcher Wall. ex Müll. Arg. The objective of this study is to identify the leaf micromorphological characteristics that can be used in species identification. The procedures involve examination under scanning electron microscope. Findings of this study have demonstrated variations in the leaf micromorphological characteristics such as in the types of waxes present on adaxial and abaxial epidermis surfaces, in the stomata and types of trichome. Common character present in all species studied are the presence of a thin film layer and buttress-like waxes on epidermal leaf surfaces. Diagnostics characters found in this study are the presence of papilla in P. elegens, amphistomatic stomata in P. urinaria and flaky waxes in P. pulcher. The result of this study has shown that leaf micromorphological characters have some taxonomic significance and can be used in identification of species in the genus Phyllanthus.

  4. Up-scaling of water use efficiency from leaf to canopy as based on leaf gas exchange relationships and the modeled in-canopy light distribution

    DEFF Research Database (Denmark)

    Linderson, Maj-Lena; Mikkelsen, Teis Nørgaard; Ibrom, Andreas

    2012-01-01

    The aim of this study was to evaluate the extent to which water use efficiency (WUE) at leaf scale can be used to assess WUE at canopy scale, leaf WUE being assumed to be a constant function of vapor pressure deficit and to thus not be dependent upon other environmental factors or varying leaf...... properties. Leaf WUE and its variability and dependencies were assessed using leafgas-exchange measurements obtained during two growing seasons, 1999 and 2000, at the Soroe beech forest study site on Zealand in Denmark. It was found that the VPD-normalized leaf WUE, WUEnormleaf, although dependent...

  5. Isotopic Discrimination During Leaf Litter Decomposition

    Science.gov (United States)

    Ngao, J.; Rubino, M.

    2006-12-01

    Methods involving stable isotopes have been successfully applied since decades in various research fields. Tracing 13C natural abundance in ecosystem compartments greatly enhanced the understanding of the C fluxes in the plant-soil-atmosphere C exchanges when compartments present different C isotopic signatures (i.e. atmospheric CO2 vs photosynthetic leaves, C3 vs C4; etc.). However, the assumption that no isotopic discrimination occurs during respiration is commonly made in numbers of C isotope-based ecological studies. Furthermore, verifications of such assumption are sparse and not enough reliable. The aim of our study is to assess the potential isotopic discrimination that may occur during litter decomposition. Leaf litter from an Arbutus unedo (L.) stand (Tolfa, Italy) was incubated in 1L jars, under constant laboratory conditions (i.e. 25 ° C and 135% WC). During the entire incubation period, gravimetric mass loss, litter respiration rates and the isotopic composition of respired CO2 are monitored at regular intervals. Data from 7 months of incubation will be presented and discussed. After two months, the litter mass loss averaged 16% of initial dry mass. During the same time-period, the respiration rate decreased significantly by 58% of the initial respiration rate. Isotopic compositions of respired CO2 ranged between -27.95‰ and - 25.69‰. Mean values did not differ significantly among the sampling days, in spite of an apparent enrichment in 13C of respired CO2 with time. The significance of these isotopic enrichment will be determined at a longer time scale. They may reveal both/either a direct microbial discrimination during respiration processes and/or a use of different litter compounds as C source along time. Further chemical and compound-specific isotopic analysis of dry matter will be performed in order to clarify these hypotheses. This work is part of the "ALICE" project, funded by the European Union's Marie Curie Fellowship Actions that aims to

  6. Incorporating multi-leaf collimator leaf sequencing into iterative IMRT optimization

    International Nuclear Information System (INIS)

    Siebers, Jeffrey V.; Lauterbach, Marc; Keall, Paul J.; Mohan, Radhe

    2002-01-01

    Intensity modulated radiation therapy (IMRT) treatment planning typically considers beam optimization and beam delivery as separate tasks. Following optimization, a multi-leaf collimator (MLC) or other beam delivery device is used to generate fluence patterns for patient treatment delivery. Due to limitations and characteristics of the MLC, the deliverable intensity distributions often differ from those produced by the optimizer, leading to differences between the delivered and the optimized doses. Objective function parameters are then adjusted empirically, and the plan is reoptimized to achieve a desired deliverable dose distribution. The resulting plan, though usually acceptable, may not be the best achievable. A method has been developed to incorporate the MLC restrictions into the optimization process. Our in-house IMRT system has been modified to include the calculation of the deliverable intensity into the optimizer. In this process, prior to dose calculation, the MLC leaf sequencer is used to convert intensities to dynamic MLC sequences, from which the deliverable intensities are then determined. All other optimization steps remain the same. To evaluate the effectiveness of deliverable-based optimization, 17 patient cases have been studied. Compared with standard optimization plus conversion to deliverable beams, deliverable-based optimization results show improved isodose coverage and a reduced dose to critical structures. Deliverable-based optimization results are close to the original nondeliverable optimization results, suggesting that IMRT can overcome the MLC limitations by adjusting individual beamlets. The use of deliverable-based optimization may reduce the need for empirical adjustment of objective function parameters and reoptimization of a plan to achieve desired results

  7. Dependence of fluence errors in dynamic IMRT on leaf-positional errors varying with time and leaf number

    International Nuclear Information System (INIS)

    Zygmanski, Piotr; Kung, Jong H.; Jiang, Steve B.; Chin, Lee

    2003-01-01

    In d-MLC based IMRT, leaves move along a trajectory that lies within a user-defined tolerance (TOL) about the ideal trajectory specified in a d-MLC sequence file. The MLC controller measures leaf positions multiple times per second and corrects them if they deviate from ideal positions by a value greater than TOL. The magnitude of leaf-positional errors resulting from finite mechanical precision depends on the performance of the MLC motors executing leaf motions and is generally larger if leaves are forced to move at higher speeds. The maximum value of leaf-positional errors can be limited by decreasing TOL. However, due to the inherent time delay in the MLC controller, this may not happen at all times. Furthermore, decreasing the leaf tolerance results in a larger number of beam hold-offs, which, in turn leads, to a longer delivery time and, paradoxically, to higher chances of leaf-positional errors (≤TOL). On the other end, the magnitude of leaf-positional errors depends on the complexity of the fluence map to be delivered. Recently, it has been shown that it is possible to determine the actual distribution of leaf-positional errors either by the imaging of moving MLC apertures with a digital imager or by analysis of a MLC log file saved by a MLC controller. This leads next to an important question: What is the relation between the distribution of leaf-positional errors and fluence errors. In this work, we introduce an analytical method to determine this relation in dynamic IMRT delivery. We model MLC errors as Random-Leaf Positional (RLP) errors described by a truncated normal distribution defined by two characteristic parameters: a standard deviation σ and a cut-off value Δx 0 (Δx 0 ∼TOL). We quantify fluence errors for two cases: (i) Δx 0 >>σ (unrestricted normal distribution) and (ii) Δx 0 0 --limited normal distribution). We show that an average fluence error of an IMRT field is proportional to (i) σ/ALPO and (ii) Δx 0 /ALPO, respectively, where

  8. [Seasonal differences in the leaf hydraulic conductance of mature Acacia mangium in response to its leaf water use and photosynthesis].

    Science.gov (United States)

    Zhao, Ping; Sun, Gu-Chou; Ni, Guang-Yan; Zeng, Xiao-Ping

    2013-01-01

    In this study, measurements were made on the leaf water potential (psi1), stomatal conductance (g(s)), transpiration rate, leaf area index, and sapwood area of mature Acacia mangium, aimed to understand the relationships of the leaf hydraulic conductance (K1) with the leaf water use and photosynthetic characteristics of the A. mangium in wet season (May) and dry season (November). The ratio of sapwood area to leaf area (A(sp)/A(cl)) of the larger trees with an average height of 20 m and a diameter at breast height (DBH) of 0.26 m was 8.5% higher than that of the smaller trees with an average height of 14.5 m and a DBH of 0.19 m, suggesting that the larger trees had a higher water flux in their leaf xylem, which facilitated the water use of canopy leaf. The analysis on the vulnerability curve of the xylem showed that when the K1 decreased by 50%, the psi1 in wet season and dry season was -1.41 and -1.55 MPa, respectively, and the vulnerability of the xylem cavitation was higher in dry season than in wet season. The K1 peak value in wet season and dry season was 5.5 and 4.5 mmol x m(-2) x s(-1) x MPa(-1), and the maximum transpiration rate (T(r max)) was 3.6 and 1.8 mmol x m(-2) x s(-1), respectively. Both the K1 and T(r max), were obviously higher in wet season than in dry season. Within a day, the K1 and T(r), fluctuated many times, reflecting the reciprocated cycle of the xylem cavitation and refilling. The leaf stomatal closure occurred when the K1 declined over 50% or the psi1 reached -1.6 MPa. The g(s) would be maintained at a high level till the K1 declined over 50%. The correlation between the hydraulic conductance and photosynthetic rate was more significant in dry season than in wet season. The loss of leaf hydraulic conductance induced by seasonal change could be the causes of the decrease of T(r) and CO2 gas exchange.

  9. Measurement of Leaf Mass and Leaf Area of Oaks In A Mediterranean-climate Region For Biogenic Emission Estimation

    Science.gov (United States)

    Karlik, J.

    Given the key role played by biogenic volatile organic compounds (BVOC) in tro- pospheric chemistry and regional air quality, it is critical to generate accurate BVOC emission inventories. Because several oak species have high BVOC emission rates, and oak trees are often of large stature with corresponding large leaf masses, oaks may be the most important genus of woody plants for BVOC emissions modeling in the natural landscapes of Mediterranean-climate regions. In California, BVOC emis- sions from oaks may mix with anthropogenic emissions from urban areas, leading to elevated levels of ozone. Data for leaf mass and leaf area for a stand of native blue oaks (Quercus douglasii) were obtained through harvest and leaf removal from 14 trees lo- cated in the Sierra Nevada foothills of central California. Trees ranged in height from 4.2 to 9.9 m, with trunk diameters at breast height of 14 to 85 cm. Mean leaf mass density was 730 g m-2 for the trees and had an overall value of 310 g m-2 for the site. Consideration of the surrounding grassland devoid of trees resulted in a value of about 150 g m-2, less than half of reported values for eastern U.S. oak woodlands, but close to a reported value for oaks found in St. Quercio, Italy. The mean value for leaf area index (LAI) for the trees at this site was 4.4 m2 m-2. LAI for the site was 1.8 m2 m-2, but this value was appropriate for the oak grove only; including the surrounding open grassland resulted in an overall LAI value of 0.9 m2 m-2 or less. A volumetric method worked well for estimating the leaf mass of the oak trees. Among allometric relationships investigated, trunk circumference, mean crown radius, and crown projec- tion were well correlated with leaf mass. Estimated emission of isoprene (mg C m-2 h-1) for the site based these leaf mass data and experimentally determined emission rate was similar to that reported for a Mediterranean oak woodland in France.

  10. Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells.

    Science.gov (United States)

    Akita, Kae; Higaki, Takumi; Kutsuna, Natsumaro; Hasezawa, Seiichiro

    2015-01-01

    Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells.

  11. Bean leaf growth response to moderate ozone levels

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L S

    1973-01-01

    The middle leaflet from the first trifoliate leaf of pinto bean plants (Phaseolus vulgaris) was subjected to various ozone levels for both 12 and 24 h to show moderate oxidant injury. Rates of leaf expansion were used as criteria to measure the effects of ozone at three leaflet positions. Growth analysis included Y-intercepts indicating growth after day 1, growth after day 3, and regression line slopes between days 1 and 7 after the beginning of the experiments. Slopes of growth rate regression lines differentiated untreated leaflets from leaflets exposed to a 0.60 ppm-h (0.05 ppm for 12 h) dose. Growth rates of plants exposed to 1.20 ppm-h (either 0.05 ppm for 24 h, or 0.10 ppm for 12 h) were distinguishable from untreated plants within three days. Basal leaf portions showed the most differential ozone response compared with lateral and tip positions.

  12. Mangifera indica L. leaf extract alleviates doxorubicin induced cardiac stress

    Science.gov (United States)

    Bhatt, Laxit; Joshi, Viraj

    2017-01-01

    Aim: The study was undertaken to evaluate the cardioprotective effect of the alcoholic leaf extract of Mangifera indica L. against cardiac stress caused by doxorubicin (DOX). Materials and Methods: Rats were treated with 100 mg/kg of M. indica leaf extract (MILE) in alone and interactive groups for 21 days. Apart from the normal and MILE control groups, all the groups were subjected to DOX (15 mg/kg, i.p.) toxicity for 21 days and effects of different treatments were analyzed by changes in serum biomarkers, tissue antioxidant levels, electrocardiographic parameters, lipid profile, and histopathological evaluation. Results: The MILE treated group showed decrease in serum biomarker enzyme levels and increase in tissue antioxidants levels. Compared to DOX control group, MILE treated animals showed improvement in lipid profile, electrocardiographic parameters, histological score, and mortality. Conclusion: These findings clearly suggest the protective role of alcoholic leaf extract of M. indica against oxidative stress induced by DOX. PMID:28894627

  13. Monosaccharide analysis of succulent leaf tissue in Aloe

    DEFF Research Database (Denmark)

    Grace, Olwen Megan; Dzajic, Amra; Jäger, Anna

    2013-01-01

    in the genus Aloe using a predictive phylogenetic approach. Methodology – Monosaccharide composition was assessed in 31species, representing the morphological and taxonomic diversity of Aloe sensu stricto. Leaf mesophyll polysaccharides were partially hydrolysed in a trifluoroacetic acid (TFA)-SilA assay......Introduction – The succulent leaf mesophyll in Aloe species supports a burgeoning natural products industry, particularly in Africa. Comparative data necessary to prioritise species with economic potential have been lacking. Objective – To survey leaf mesophyll monosaccharide composition....... Oximes and trimethylsilyl ether products were detected by GC-MS. Constituent monosaccharides accounting for the greatest variation among species were identified by principal component analysis. Two plant DNA barcoding regions were sequenced in 28 of the sampled species and the resulting maximum...

  14. Image Segmentation of Historical Handwriting from Palm Leaf Manuscripts

    Science.gov (United States)

    Surinta, Olarik; Chamchong, Rapeeporn

    Palm leaf manuscripts were one of the earliest forms of written media and were used in Southeast Asia to store early written knowledge about subjects such as medicine, Buddhist doctrine and astrology. Therefore, historical handwritten palm leaf manuscripts are important for people who like to learn about historical documents, because we can learn more experience from them. This paper presents an image segmentation of historical handwriting from palm leaf manuscripts. The process is composed of three steps: 1) background elimination to separate text and background by Otsu's algorithm 2) line segmentation and 3) character segmentation by histogram of image. The end result is the character's image. The results from this research may be applied to optical character recognition (OCR) in the future.

  15. Spilocaea pyracanthae causing leaf scab on loquat in Pakistan

    Directory of Open Access Journals (Sweden)

    Haris Butt

    2016-03-01

    Full Text Available ABSTRACT Loquat is attacked by many phytopathogenic fungi. Among these Spilocaea pyracanthae is of economic importance. The fungus received no attention in Pakistan and some other parts of the world. The current study is focused on the symptomatology of this disease and the etiology of the fungus. During extensive surveys of loquat orchards in 2013 heavy infestations of this disease were observed. The leaf symptoms were observed as olive brown, opaque necrotic sub-circular spots, with light brown coloration in the center. Two or more spots coalesced in severe infections covering large leaf areas. The fungus was identified as Spilocaea pyracanthae on the basis of conidia and morphological characters. The pathogenicity of the fungus was confirmed on healthy plants under greenhouse conditions by following Koch's postulates. The fungus produced characteristic leaf scab symptoms on young leaves. This is the first report of Spilocaea pyracanthae causing leafscab of loquat in Pakistan.

  16. Occurrence of barley leaf disease and control strategies in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Lise Nistrup; Ørum, Jens Erik; Heick, Thies Marten

    Barley (Hordeum vulgare) is one of the major crops in Denmark and of special importance for malting and for pig feed. In 2016, the crop was grown covering a total area of 700,000 ha; approximately 25% of arable area in Denmark. To ensure high yield of around 60 dt ha-1, disease-tolerant cultivars...... have proven to be quite effective against all leaf diseases, aside from brown rust and mildew. Denmark has a national record system for pesticide usages. All farmers upload their fungicide use by crop, creating a good basis for assessing the differences in use pattern across different regions...... and fungicide treatments are required. Each year, barley cultivars are assessed for susceptibility towards leaf diseases in national observation plots. The most predominant fungal leaf diseases in Denmark are barley scald (Rhynchosporium secalis), net blotch (Pyrenophora teres), brown rust (Puccinia hordei...

  17. Induced mutations for resistance to leaf rust in wheat

    International Nuclear Information System (INIS)

    Borojevic, K.

    1983-01-01

    Problems related to the induction of mutations for disease resistance were investigated under several aspects, using the wheat/leaf rust system. Previously selected mutant lines, tested in M 11 and M 13 , were found to differ with regard to infection type and disease severity from the original varieties. To verify the induced-mutation origin, these mutants were examined further using test crosses with carriers of known genes for leaf rust resistance and electrophoresis. A separate experiment to induce mutations for leaf rust resistance in the wheat varieties Sava, Aurora and Siete Cerros, using gamma rays, fast neutrons and EMS, yielded mutants with different disease reaction in the varieties Sava and Aurora at a frequency of about 1x10 - 3 per M 1 plant progenies. (author)

  18. Physical properties of snacks made from cassava leaf flour

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Ferrari

    2014-02-01

    Full Text Available The food industry is continually growing with new products becoming available every year. Extrusion combines a number of unit operations in one energy efficient rapid continuous process and can be used to produce a wide variety of snacks foods. The objective of this study was to evaluate the effect of extrusion temperature, screw speed, and amount of cassava leaf flour mixed with cassava starch on the physical properties of extruded snacks processed using a single screw extruder. A central composite rotational design, including three factors with 20 treatments, was used in the experimental design. Dependent variables included the expansion index, specific volume, color, water absorption index, and water solubility index. Among the parameters examined, the amount of cassava leaf flour and extrusion temperature showed significant effects on extruded snack characteristics. Mixtures containing 10% of cassava leaf flour extruded at 100°C and 255 rpm shows favorable levels of expansion, color, water absorption index, and water solubility index.

  19. Reading the Leaves: A Comparison of Leaf Rank and Automated Areole Measurement for Quantifying Aspects of Leaf Venation

    Directory of Open Access Journals (Sweden)

    Walton A. Green

    2014-08-01

    Full Text Available The reticulate venation that is characteristic of a dicot leaf has excited interest from systematists for more than a century, and from physiological and developmental botanists for decades. The tools of digital image acquisition and computer image analysis, however, are only now approaching the sophistication needed to quantify aspects of the venation network found in real leaves quickly, easily, accurately, and reliably enough to produce biologically meaningful data. In this paper, we examine 120 leaves distributed across vascular plants (representing 118 genera and 80 families using two approaches: a semiquantitative scoring system called “leaf ranking,” devised by the late Leo Hickey, and an automated image-analysis protocol. In the process of comparing these approaches, we review some methodological issues that arise in trying to quantify a vein network, and discuss the strengths and weaknesses of automatic data collection and human pattern recognition. We conclude that subjective leaf rank provides a relatively consistent, semiquantitative measure of areole size among other variables; that modal areole size is generally consistent across large sections of a leaf lamina; and that both approaches—semiquantitative, subjective scoring; and fully quantitative, automated measurement—have appropriate places in the study of leaf venation.

  20. Non-destructive measurement of soybean leaf thickness via X-ray computed tomography allows the study of diel leaf growth rhythms in the third dimension.

    Science.gov (United States)

    Pfeifer, Johannes; Mielewczik, Michael; Friedli, Michael; Kirchgessner, Norbert; Walter, Achim

    2018-01-01

    Present-day high-resolution leaf growth measurements provide exciting insights into diel (24-h) leaf growth rhythms and their control by the circadian clock, which match photosynthesis with oscillating environmental conditions. However, these methods are based on measurements of leaf area or elongation and neglect diel changes of leaf thickness. In contrast, the influence of various environmental stress factors to which leaves are exposed to during growth on the final leaf thickness has been studied extensively. Yet, these studies cannot elucidate how variation in leaf area and thickness are simultaneously regulated and influenced on smaller time scales. Only few methods are available to measure the thickness of young, growing leaves non-destructively. Therefore, we evaluated X-ray computed tomography to simultaneously and non-invasively record diel changes and growth of leaf thickness and area. Using conventional imaging and X-ray computed tomography leaf area, thickness and volume growth of young soybean leaves were simultaneously and non-destructively monitored at three cardinal time points during night and day for a period of 80 h under non-stressful growth conditions. Reference thickness measurements on paperboards were in good agreement to CT measurements. Comparison of CT with leaf mass data further proved the consistency of our method. Exploratory analysis showed that measurements were accurate enough for recording and analyzing relative diel changes of leaf thickness, which were considerably different to those of leaf area. Relative growth rates of leaf area were consistently positive and highest during 'nights', while diel changes in thickness fluctuated more and were temporarily negative, particularly during 'evenings'. The method is suitable for non-invasive, accurate monitoring of diel variation in leaf volume. Moreover, our results indicate that diel rhythms of leaf area and thickness show some similarity but are not tightly coupled. These

  1. Weak leaf photosynthesis and nutrient content relationships from tropical vegetation

    Science.gov (United States)

    Domingues, T. F.; Ishida, F. Y.; Feldpaush, T.; Saiz, G.; Grace, J.; Meir, P.; Lloyd, J.

    2015-12-01

    Evergreen rain forests and savannas are the two major vegetations of tropical land ecosystems, in terms of land area, biomass, biodiversity, biogeochemical cycles and rates of land use change. Mechanistically understanding ecosystem functioning on such ecosystems is still far from complete, but important for generation of future vegetation scenarios in response to global changes. Leaf photosynthetic rates is a key processes usually represented on land surface-atmosphere models, although data from tropical ecosystems is scarce, considering the high biodiversity they contain. As a shortcut, models usually recur to relationships between leaf nutrient concentration and photosynthetic rates. Such strategy is convenient, given the possibility of global datasets on leave nutrients derived from hyperspectral remote sensing data. Given the importance of Nitrogen on enzyme composition, this nutrient is usually used to infer photosynthetic capacity of leaves. Our experience, based on individual measurements on 1809 individual leaves from 428 species of trees and shrubs naturally occurring on tropical forests and savannas from South America, Africa and Australia, indicates that the relationship between leaf nitrogen and its assimilation capacity is weak. Therefore, leaf Nitrogen alone is a poor predictor of photosynthetic rates of tropical vegetation. Phosphorus concentrations from tropical soils are usually low and is often implied that this nutrient limits primary productivity of tropical vegetation. Still, phosphorus (or other nutrients) did not exerted large influence over photosynthetic capacity, although potassium influenced vegetation structure and function. Such results draw attention to the risks of applying universal nitrogen-photosynthesis relationships on biogeochemical models. Moreover, our data suggests that affiliation of plant species within phylogenetic hierarchy is an important aspect in understanding leaf trait variation. The lack of a strong single

  2. Safety evaluation of Sapindus laurifolius leaf extract in Wistar rats

    Directory of Open Access Journals (Sweden)

    C. N. Santhosh Kumar

    2013-10-01

    Full Text Available Objectives:The present work was aimed to study the phytochemical composition of the Sapindus laurifolius leaves andtoxicological effect of the Sapindus laurifolius leaf extract in a systematic way using Wistar albino rats as a model animal.Materials and Methods :The identification of phytoconstituents present in the leaf extract was performed using Highperformance thin layer chromatography (HPTLC. In toxicity studies, the acute oral toxicity study was conducted as per theguidelines of Organization for Economic Co-operation and Development (OECD 423 Acute Toxic Class Method for testingof chemicals. In repeated dose 28-day oral toxicity study (OECD 407, methanolic leaf extract administered at the dose of 50,200 and 800 mg/kg BWand limit dose of 1000 mg/kg BW.Results: Saponins, flavanoids, glycosides and bitter principles were the major phytoconstituents identified. In acute toxicitystudy, the LD cut-off values were found to be more than 2g/kg in leaf extract. In repeated dose 28-day oral toxicity, significant 50(P<0.05 increase in AST, ALT, BUN and creatinine, significant (P<0.05 increase in total protein was noticed. Thehistopathological changes confined to liver, kidney and intestine, revealed mild to moderate hepatotoxicity, severenephrotoxicity and increased goblet cell activity. The changes were found to correlate with increased dose of leaf extract.Conclusion:The phytochemical analysis of Sapindus laurifolius revealed the presence of saponins, glycosides, flavonoidsand bitter principles.The acute oral toxicity study of S. laurifolius methanolic leaf extract in rats resulted in no toxicity even atthe highest dose, but in repeated 28-day oral toxicity study revealed mild to moderate hepatotoxicity, severe nephrotoxicityand intestinal damage.

  3. Influence of MLC leaf width on biologically adapted IMRT plans

    Energy Technology Data Exchange (ETDEWEB)

    Roedal, Jan; Soevik, Aaste; Malinen, Eirik (Dept. of Medical Physics, The Norwegian Radium Hospital, Oslo Univ. Hospital, Oslo (Norway)), E-mail: jan.rodal@radiumhospitalet.no

    2010-10-15

    Introduction. High resolution beam delivery may be required for optimal biology-guided adaptive therapy. In this work, we have studied the influence of multi leaf collimator (MLC) leaf widths on the treatment outcome following adapted IMRT of a hypoxic tumour. Material and methods. Dynamic contrast enhanced MR images of a dog with a spontaneous tumour in the nasal region were used to create a tentative hypoxia map following a previously published procedure. The hypoxia map was used as a basis for generating compartmental gross tumour volumes, which were utilised as planning structures in biologically adapted IMRT. Three different MLCs were employed in inverse treatment planning, with leaf widths of 2.5 mm, 5 mm and 10 mm. The number of treatment beams and the degree of step-and-shoot beam modulation were varied. By optimising the tumour control probability (TCP) function, optimal compartmental doses were derived and used as target doses in the inverse planning. Resulting IMRT dose distributions and dose volume histograms (DVHs) were exported and analysed, giving estimates of TCP and compartmental equivalent uniform doses (EUDs). The impact of patient setup accuracy was simulated. Results. The MLC with the smallest leaf width (2.5 mm) consistently gave the highest TCPs and compartmental EUDs, assuming no setup error. The difference between this MLC and the 5 mm MLC was rather small, while the MLC with 10 mm leaf width gave considerably lower TCPs. When including random and systematic setup errors, errors larger than 5 mm gave only small differences between the MLC types. For setup errors larger than 7 mm no differences were found between non-uniform and uniform dose distributions. Conclusions. Biologically adapted radiotherapy may require MLCs with leaf widths smaller than 10 mm. However, for a high probability of cure it is crucial that accurate patient setup is ensured.

  4. Estimates of Leaf Relative Water Content from Optical Polarization Measurements

    Science.gov (United States)

    Dahlgren, R. P.; Vanderbilt, V. C.; Daughtry, C. S. T.

    2017-12-01

    Remotely sensing the water status of plant canopies remains a long term goal of remote sensing research. Existing approaches to remotely sensing canopy water status, such as the Crop Water Stress Index (CWSI) and the Equivalent Water Thickness (EWT), have limitations. The CWSI, based upon remotely sensing canopy radiant temperature in the thermal infrared spectral region, does not work well in humid regions, requires estimates of the vapor pressure deficit near the canopy during the remote sensing over-flight and, once stomata close, provides little information regarding the canopy water status. The EWT is based upon the physics of water-light interaction in the 900-2000nm spectral region, not plant physiology. Our goal, development of a remote sensing technique for estimating plant water status based upon measurements in the VIS/NIR spectral region, would potentially provide remote sensing access to plant dehydration physiology - to the cellular photochemistry and structural changes associated with water deficits in leaves. In this research, we used optical, crossed polarization filters to measure the VIS/NIR light reflected from the leaf interior, R, as well as the leaf transmittance, T, for 78 corn (Zea mays) and soybean (Glycine max) leaves having relative water contents (RWC) between 0.60 and 0.98. Our results show that as RWC decreases R increases while T decreases. Our results tie R and T changes in the VIS/NIR to leaf physiological changes - linking the light scattered out of the drying leaf interior to its relative water content and to changes in leaf cellular structure and pigments. Our results suggest remotely sensing the physiological water status of a single leaf - and perhaps of a plant canopy - might be possible in the future.

  5. [Spectrum Variance Analysis of Tree Leaves Under the Condition of Different Leaf water Content].

    Science.gov (United States)

    Wu, Jian; Chen, Tai-sheng; Pan, Li-xin

    2015-07-01

    Leaf water content is an important factor affecting tree spectral characteristics. So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are not only the keys of hyperspectral vegetation remote sensing information identification but also the theoretical support of research on vegetation spectrum change as the differences in leaf water content. The spectrometer was used to observe six species of tree leaves, and the reflectivity and first order differential spectrum of different leaf water content were obtained. Then, the spectral characteristics of each tree species leaves under the condition of different leaf water content were analyzed, and the spectral differences of different tree species leaves under the condition of the same leaf water content were compared to explore possible bands of the leaf water content identification by hyperspectral remote sensing. Results show that the spectra of each tree leaf have changed a lot with the change of the leaf water content, but the change laws are different. Leaf spectral of different tree species has lager differences in some wavelength range under the condition of same leaf water content, and it provides some possibility for high precision identification of tree species.

  6. LEAF SURFACE COMPARISON OF THREE GENERA OF ARACEAE IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Ina Erlinawati

    2013-07-01

    Full Text Available Alocasia, Colocasia and Remusatia are the genera of Araceae family which have high economic value, such as for food and ornamental plants. Those three genera, previously treated as Colocasieae tribe. Later, based on Nauheimer, L. et al. study in 2012, using plastid and nuclear DNA, Alocasia is placed in different tribe. Study on leaf anatomy of Araceae is still poor known. Comparison of three genera of Araceae, indicates a difference in the epidermis. Alocasia and Colocasia have stomata on both leaf surfaces (amphistomatic but Remusatia has stomata only limited on the lower surface. The three genera can be distinguished from epidermal cell shape, stomata complex and the presence of stomata.

  7. Hyperbolic projections of siemens 3d-mlc leaf paths

    International Nuclear Information System (INIS)

    Menzies, N.

    2004-01-01

    Full text: The Siemens Primus linear accelerator has the option of being fitted with a multi-leaf collimator (3D-MLC) that is marketed as having 'double focus', to achieve a constant dose penumbra for all leaf settings. This is achieved by moving the leaves through arcs (similar to some conventional collimator jaws), as well as shaping the leaf side-faces as divergent planes from the x-ray source. One consequence of the mechanical design of the 3D-MLC is that as individual leaves are moved, their projections from the light / x-ray source to the treatment plane follow paths that are hyperbolic, as shown in the figure below. (The eccentricity of the hyperbola is a function of leaf number / distance from centre.) The trajectories of the MLC leaves were modelled (in a spreadsheet) using geometrical projections of the MLC leaves to the treatment plane, with construction details provided in Siemens documentation. The results were checked against the image of the leaf in the linac light field. This problem belongs to the class of conic sections in mathematics, where the intersection of a plane with both nappes of a double right circular cone results in a hyperbola. The good agreement between the model and the light field image provided confirmation of the MLC construction details. AS/NZS 4434.1:1996 (reproduced from IEC 976:1989) provides specifications for maximum deviation from orthogonality of adjacent edges, which can be interpreted for MLC collimators to parallelism of the direction of leaf travel and the adjacent collimator edge (e.g. Elekta ATS). However for the Siemens 'double focused' MLC, it is demonstrated that the geometrical construction of the MLC militates against the leaf image being used for this kind of test. It is also demonstrated that at last one commercial treatment planning system models the Siemens leaf trajectories linearly. The clinical significance of the error in this model is shown to be negligible. Copyright (2004) Australasian College of

  8. Deferral of leaf senescence and increased productivity in rice

    International Nuclear Information System (INIS)

    Biswas, A.K.; Choudhari, M.A.

    1978-01-01

    The effect of spraying of different hormones and nurtient solutions on plants at 3 developmental stages of growth of Jaya rice has been studied. Increased plant growth and leaf longevity have been correlated with increased yield of the crop. 32 P feeding experiments showed that major export of materials took place from flag leaf to grains, while various treatments with hormones and nutrients could modify this export by implicating other leaves as well. These data also support the increased yield and longevity of the top. (author)

  9. The distribution of metal elements in plant leaf. Second report

    International Nuclear Information System (INIS)

    Ohnishi, Toshiyuki; Masuko, Shoji; Noya, Youichi; Kasahara, Shigeru

    2002-01-01

    We have reported in first report as to metal elements containing in some leaf such as clethra, bamboo and maple. This time, we measured the contents zinc, cesium and cobalt about clethra, maple in root, blanch and anthotaxy. As to cesium, the density contained in anthotaxy of clethra was 1.5 times as much as that of soil. In the same manner, the density of cobalt contained in the blanch of clethra was 10 times as much as that of maple. As to zinc, the difference contained root, blanch and leaf between clethra and maple were small. (author)

  10. Leaf Dynamics of Panicum maximum under Future Climatic Changes.

    Science.gov (United States)

    Britto de Assis Prado, Carlos Henrique; Haik Guedes de Camargo-Bortolin, Lívia; Castro, Érique; Martinez, Carlos Alberto

    2016-01-01

    Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy warming (eC+eT). The temperatures and CO2 in the field were controlled by temperature free-air controlled enhancement (T-FACE) and mini free-air CO2 enrichment (miniFACE) facilities. The most green, expanding, and expanded leaves and the highest leaf appearance rate (LAR, leaves day(-1)) and leaf elongation rate (LER, cm day(-1)) were observed under eT. Leaf area and leaf biomass were higher in the eT and eC+eT treatments. The higher LER and LAR without significant differences in the number of senescent leaves could explain why tillers had higher foliage area and leaf biomass in the eT treatment. The eC treatment had the lowest LER and the fewest expanded and green leaves, similar to Control. The inhibitory effect of eC on foliage development in winter was indicated by the fewer green, expanded, and expanding leaves under eC+eT than eT. The stimulatory and inhibitory effects of the eT and eC treatments, respectively, on foliage raised and lowered, respectively, the foliar nitrogen concentration. The inhibition of foliage by eC was confirmed by the eC treatment having the lowest leaf/stem biomass ratio and by the change in leaf biomass-area relationships from linear or exponential growth to rectangular hyperbolic growth under eC. Besides, eC+eT had a synergist effect, speeding up leaf maturation. Therefore, with sufficient water and nutrients in winter, the inhibitory effect of elevated CO2 on foliage could be partially offset by elevated temperatures and relatively high P. maximum foliage production could be achieved under future climatic change.

  11. Ephemeroptera, Plecoptera and Trichoptera (Insecta) Abundance, Diversity and Role in Leaf Litter Breakdown in Tropical Headwater River.

    Science.gov (United States)

    Ab Hamid, Suhaila; Md Rawi, Che Salmah

    2017-07-01

    Leaf litter decomposition in a tropical stream was examined in two types of leaf packs; single species leaf packs of Pometia pinnata and two species leaf packs of equal combination of Pometia pinnata and Dolichandrone spathacea leaves. Both leaf packs were immersed in a river and weekly examined for remains of decomposed leaves and presence of EPT. In the control leaf packs, leaves in the two species leaf packs treatments decomposed within 35 days, faster than in single species leaf packs which decomposed after 42 days. In the presence of EPT, the leaf breakdown took 28 days in two species and 35 days for single species leaf packs. Higher abundance of EPT was observed in single species leaf packs but its diversity was higher in two species leaf packs. Litter breakdown in the stream was faster in the presence of EPT and softer leaves of D. spathacea with higher nitrogen content underwent faster decomposition and sustained higher numbers of EPT.

  12. Inheritance of okra leaf type in different genetic backgrounds and its ...

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... trait was studied in three cross combinations involving a common okra leaf parent ... pests with reduced leaf area allowing better air flow and maximum sunlight .... Irrigation both by canal and turbine water was applied to the.

  13. The plant leaf movement analyzer (PALMA): a simple tool for the analysis of periodic cotyledon and leaf movement in Arabidopsis thaliana.

    Science.gov (United States)

    Wagner, Lucas; Schmal, Christoph; Staiger, Dorothee; Danisman, Selahattin

    2017-01-01

    The analysis of circadian leaf movement rhythms is a simple yet effective method to study effects of treatments or gene mutations on the circadian clock of plants. Currently, leaf movements are analysed using time lapse photography and subsequent bioinformatics analyses of leaf movements. Programs that are used for this purpose either are able to perform one function (i.e. leaf tip detection or rhythm analysis) or their function is limited to specific computational environments. We developed a leaf movement analysis tool-PALMA-that works in command line and combines image extraction with rhythm analysis using Fast Fourier transformation and non-linear least squares fitting. We validated PALMA in both simulated time series and in experiments using the known short period mutant sensitivity to red light reduced 1 ( srr1 - 1 ). We compared PALMA with two established leaf movement analysis tools and found it to perform equally well. Finally, we tested the effect of reduced iron conditions on the leaf movement rhythms of wild type plants. Here, we found that PALMA successfully detected period lengthening under reduced iron conditions. PALMA correctly estimated the period of both simulated and real-life leaf movement experiments. As a platform-independent console-program that unites both functions needed for the analysis of circadian leaf movements it is a valid alternative to existing leaf movement analysis tools.

  14. Impact of Vertical Canopy Position on Leaf Spectral Properties and Traits across Multiple Species

    Directory of Open Access Journals (Sweden)

    Tawanda W. Gara

    2018-02-01

    Full Text Available Understanding the vertical pattern of leaf traits across plant canopies provide critical information on plant physiology, ecosystem functioning and structure and vegetation response to climate change. However, the impact of vertical canopy position on leaf spectral properties and subsequently leaf traits across the entire spectrum for multiple species is poorly understood. In this study, we examined the ability of leaf optical properties to track variability in leaf traits across the vertical canopy profile using Partial Least Square Discriminatory Analysis (PLS-DA. Leaf spectral measurements together with leaf traits (nitrogen, carbon, chlorophyll, equivalent water thickness and specific leaf area were studied at three vertical canopy positions along the plant stem: lower, middle and upper. We observed that foliar nitrogen (N, chlorophyll (Cab, carbon (C, and equivalent water thickness (EWT were higher in the upper canopy leaves compared with lower shaded leaves, while specific leaf area (SLA increased from upper to lower canopy leaves. We found that leaf spectral reflectance significantly (P ≤ 0.05 shifted to longer wavelengths in the ‘red edge’ spectrum (685–701 nm in the order of lower > middle > upper for the pooled dataset. We report that spectral bands that are influential in the discrimination of leaf samples into the three groups of canopy position, based on the PLS-DA variable importance projection (VIP score, match with wavelength regions of foliar traits observed to vary across the canopy vertical profile. This observation demonstrated that both leaf traits and leaf reflectance co-vary across the vertical canopy profile in multiple species. We conclude that canopy vertical position has a significant impact on leaf spectral properties of an individual plant’s traits, and this finding holds for multiple species. These findings have important implications on field sampling protocols, upscaling leaf traits to canopy level

  15. DETERMINATION OF LEAF AREA AND PLANT COVER BY USING DIGITAL IMAGE PROCESSING

    OpenAIRE

    LŐKE, ZS.; SOÓS, G.

    2002-01-01

    The development of different crop models, and crop simulation models in particular, pointed out the importance of quantifying the exact value of the leaf area. To measure the leaf size of plants of pinnatifid form, automatic, portable leaf area meters are necessary. In most places these instruments are not available to measure the assimilatory surface size of crops with special leaf shapes. Any cheap and effective method, that could replace the application of expensive portable area meters co...

  16. aqueous leaf extract of rothmannia longiflora improves basal

    African Journals Online (AJOL)

    Daniel Owu

    E-mail: ikpidanielewa@yahoo.com. Summary: This study evaluated the action of aqueous leaf extract of Rothmannia longiflora on basal metabolic .... Animals and Induction of Diabetes. Fifteen male rats of Wistar strain weighing .... lipids have a higher concentration of energy than do carbohydrates. Therefore in their ...

  17. Pretreatment of albino rats with aqueous leaf extract of Ziziphus ...

    African Journals Online (AJOL)

    Purpose: The effect of the aqueous extract of Ziziphus mauritiana leaf on hepatic lipid peroxidation, reduced glutathione and total antioxidant status was studied in chronic alcohol-induced liver damage. Method: Alcohol-induced liver toxicity was created by oral administration of 40% alcohol solution (v/v, 1ml/100g) to rats for ...

  18. Spectroscopic determination of leaf water content using linear ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-02-02

    Feb 2, 2012 ... characteristics, this study measured 33 groups of peach tree leaf ... spectral absorption values were obtained from a total of 33 groups of leaves .... using the trial and error method, based on the following empirical ... be used as indicators for evaluation of prediction models. .... Comparison of the methods of.

  19. Genetic diversity and population structure of leaf-nosed bat ...

    African Journals Online (AJOL)

    Genetic variation and population structure of the leaf-nosed bat Hipposideros speoris were estimated using 16S rRNA sequence and microsatellite analysis. Twenty seven distinct mitochondrial haplotypes were identified from 186 individuals, sampled from eleven populations. FST test revealed significant variations ...

  20. Some of the Effects of Aqueous Leaf Extract of Cnidoscolous ...

    African Journals Online (AJOL)

    treatment for numerous ailments ranging from its ability to strengthen fingernails and darken gray hair to curing alcoholism, insomnia, gout, and scorpion stings. This study was to elucidate the effect of aqueous leaf extract of Cnidoscolus aconitifolius commonly used as food supplement on the kidney and liver of Sprague ...

  1. Effects of Psidium guajava Leaf Infusion on Streptococci viridans

    Directory of Open Access Journals (Sweden)

    Hing Yi Chen

    2016-09-01

    Full Text Available Background: Dental caries is recognized as the most important oral burden. It is caused by the formation of lactate acid formed through reaction of bacteria and carbohydrates. Streptococci viridans has been proven as the primary etiologic agents for dental caries. Low accessibility in oral care services leads the Indonesian community to use plants in order to prevent dental caries. One of those plants is Psidium guajava (pink guava. The leaves were suggested to have antimicrobial effects on some gram-positive bacteria. When the organism is resistant to specific substance tested on media, a circular/inhibition zone around a disc containing antimicrobial substance was formed. The purpose of this study was to identify the presence of inhibition zones by infusion of Psidium guajava leaf on Streptococci viridians in vitro. Methods: This laboratory experiment was carried out in September to October 2014 at the Microbiology Laboratory, Faculty of Medicine, Universitas Padjadjaran. Infusions of Psidium guajava leaf were made into four different concentrations (10%, 25%, 50% and 100%, respectively and the identification of inhibition zones on Streptococci viridans obtained from the laboratory was tested using modified disk diffusion test. Distilled water acted as negative control. The results were then interpreted after 24 hours of incubation. Every procedure was repeated three times. Results: All four concentrations of Psidium guajava leaf infusions have formed inhibition zones on the media, with the highest concentration (100% producing largest average diameter. Conclusions: The infusion of Psidium guajava leaf produces inhibition zones on Streptococci virdans in vitro.

  2. LEAF RESIDUE DECOMPOSITION OF SELECTED ATLANTIC FOREST TREE SPECIES

    Directory of Open Access Journals (Sweden)

    Helga Dias Arato

    2018-02-01

    Full Text Available ABSTRACT Biogeochemical cycling is essential to establish and maintain plant and animal communities. Litter is one of main compartments of this cycle, and the kinetics of leaf decomposition in forest litter depend on the chemical composition and environmental conditions. This study evaluated the effect of leaf composition and environmental conditions on leaf decomposition of native Atlantic Forest trees. The following species were analyzed: Mabea fistulifera Mart., Bauhinia forficata Link., Aegiphila sellowiana Cham., Zeyheria tuberculosa (Vell, Luehea grandiflora Mart. et. Zucc., Croton floribundus Spreng., Trema micrantha (L Blume, Cassia ferruginea (Schrad Schrad ex DC, Senna macranthera (DC ex Collad. H. S. Irwin and Barney and Schinus terebinthifolius Raddi (Anacardiaceae. For each species, litter bags were distributed on and fixed to the soil surface of soil-filled pots (in a greenhouse, or directly to the surface of the same soil type in a natural forest (field. Every 30 days, the dry weight and soil basal respiration in both environments were determined. The cumulative decomposition of leaves varied according to the species, leaf nutrient content and environment. In general, the decomposition rate was lowest for Aegiphila sellowiana and fastest for Bauhinia forficate and Schinus terebinthifolius. This trend was similar under the controlled conditions of a greenhouse and in the field. The selection of species with a differentiated decomposition pattern, suited for different stages of the recovery process, can help improve soil restoration.

  3. Alternaria leaf spot in Michigan and fungicide sensitivity issues

    Science.gov (United States)

    Since 2010 there has been an increase in identification of Alternaria leaf spot on sugar beet in Michigan and other growing regions in the US and Canada. In 2016, the disease was severe enough to cause economic losses in the Michigan growing region. Michigan isolates from sugar beet were examined ...

  4. Species of Cercospora associated with grey leaf spot of maize

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Groenewald, M.; Caldwell, P.; Braun, U.; Harrington, T.C.

    2006-01-01

    Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. The causal organism associated with the disease is Cercospora zeae-maydis. Two potential sibling species have been recognized as Groups I and II. The DNA sequences for the

  5. Species of Cercospora associated with grey leaf spot of maize.

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Groenewald, M.; Caldwell, P.; Braun, U.; Harrington, T.C.

    2006-01-01

    Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. The causal organism associated with the disease is Cercospora zeae-maydis. Two potential sibling species have been recognized as Groups I and II. The DNA sequences for the

  6. Comparative phytochemical and growth inhibitory studies on the leaf ...

    African Journals Online (AJOL)

    Comparative phytochemical and growth inhibitory studies on the leaf and root bark extracts of securinega Virosa (roxb ex. Willd) baill ... The growth inhibitory tests were carried out between 1-30 mg/ in a period of 24-96 h while the phytochemical screening was carried out on the plant parts using standard methods. At 24 h ...

  7. Cytotoxicity testing of aqueous extract of bitter leaf (Vernonia ...

    African Journals Online (AJOL)

    Cytotoxicity testing of aqueous extract of bitter leaf (Vernonia amygdalina Del) and sniper. 1000EC (2,3 ... man and animals.1 It is estimated that 80% of the popula- ..... evaluation of waste, surface and ground water quality using the Allium test ...

  8. Nutritional potentials of some tropical vegetable leaf meals ...

    African Journals Online (AJOL)

    Three tropical vegetable species (Talium triangulare, Amaranthus cruentus and Telfairia occidentalis) were selected based on their availability and agronomic desirability. The freshly harvested vegetable leaves were subjected to 2 processing techniques (shredding and sundrying) before milling into the vegetable leaf ...

  9. Effects of ethyl acetate leaf extracts of Vitex simplicifolia on ...

    African Journals Online (AJOL)

    The effects of oral administration of ethyl acetate leaf extract of Vitex simplicifolia on vitamins A, E and C, Superoxide dismutase (SOD) and lipid profile levels in alloxan induced diabetic Wistar rats were investigated. The study was conducted with 30 Wistar rats, assigned into six groups of five rats each, and daily ...

  10. Extraction of antioxidant pigments from dye sorghum leaf sheaths

    NARCIS (Netherlands)

    Kayode, A.P.P.; Bara, C.A.; Dalode-Vieira, G.; Linnemann, A.R.; Nout, M.J.R.

    2012-01-01

    Extraction of antioxidant biocolorant pigments from leaf sheaths of dye sorghum was optimized. Effects of temperature and ethanol concentration of the extraction solvent on the concentrations of the 3-deoxyanthocyanidins, total phenolics and total anthocyanins, and the colour parameters of the

  11. Effects of Moringa oleifera leaf extract on morphological and ...

    African Journals Online (AJOL)

    Zonocerus variegatus infestation has been found to cause a lot of devastation in the production of cassava crop plants in tropical and subtropical areas. Understanding the efficacy of Moringa oleifera leaf extract on controlling Z. variegatus is desired. The present study was conducted in the Department of Crop Science ...

  12. Effect of Moringa oleifera leaf meal on haematological parameters ...

    African Journals Online (AJOL)

    Moringa oleifera leaf meal (MOLM) was included in broiler chickens' diets at graded levels of 0, 5, 10, 15, and 20% to make 5 treatments to assess haematology, serum biochemistry and haemagglutination potential in broiler chickens fed the experimental diets. The diets were formulated to be iso-caloric and isonitrogenous.

  13. Anti-proliferative effect of Moringa oleifera Lam (Moringaceae) leaf ...

    African Journals Online (AJOL)

    Purpose: To investigate the in vitro anti-proliferative effect and mechanism of action of Moringa oleifera Lam. leaf extract on human colon carcinoma HCT116 cell line. Methods: M. oleifera leaves were extracted with methanol. It was fractionated by Sephadex LH-20 column chromatography. Several fractions were identified ...

  14. Antimicrobial activity of the leaf extracts of Moringa oleifera and ...

    African Journals Online (AJOL)

    This study evaluates the antimicrobial activity of the leaf extracts of Moringa oleifera and Jatropha curcas against Staphylococcus aureus and Escherichia coli. Different concentrations of the extracts were subjected to these organisms in which Moringa oleifera showed a higher zone of inhibition on Staphylococcus aureus ...

  15. Effects of Moringa oleifera Lam. aqueous leaf extracts on follicle ...

    African Journals Online (AJOL)

    The study evaluated the effect of Moringa oleifera aqueous leaf extracts on follicle stimulating hormone and serum cholesterol in Wistar rats. Thirty six (36) mature Wistar rats (20 male and 16 female rats) were used. The male rats were grouped into four groups with five animals each, while the female animals were grouped ...

  16. (Chlorophyta) biomass production using Moringa oleifera Lam. leaf ...

    African Journals Online (AJOL)

    Chlorella sorokiniana Shih. et Krauss, a unicellular green alga was assayed to assess its to promotion potentials response of aqueous and ethanolic leaf extracts of Moringa oleifera Lam. C. sorokiniana grown in 200 ml aliquots of modified basal medium for two weeks: was treated with the aqueous and ethanolic extracts at ...

  17. The Design and Implementation of the Leaf Area Index Sensor

    Directory of Open Access Journals (Sweden)

    Xiuhong Li

    2015-03-01

    Full Text Available The quick and accurate acquisition of crop growth parameters on a large scale is important for agricultural management and food security. The combination of photographic and wireless sensor network (WSN techniques can be used to collect agricultural information, such as leaf area index (LAI, over long distances and in real time. Such acquisition not only provides farmers with photographs of crops and suggestions for farmland management, but also the collected quantitative parameters, such as LAI, can be used to support large scale research in ecology, hydrology, remote sensing, etc. The present research developed a Leaf Area Index Sensor (LAIS to continuously monitor the growth of crops in several sampling points, and applied 3G/WIFI communication technology to remotely collect (and remotely setup and upgrade crop photos in real-time. Then the crop photos are automatically processed and LAI is estimated based on the improved leaf area index of Lang and Xiang (LAILX algorithm in LAIS. The research also constructed a database of images and other information relating to crop management. The leaf length and width method (LAILLW can accurately measure LAI through direct field harvest. The LAIS has been tested in several exemplary applications, and validation with LAI from LAILLW. The LAI acquired by LAIS had been proved reliable.

  18. Effect of Carica papaya (Linn) aqueous leaf extract on ...

    African Journals Online (AJOL)

    Purpose: To investigate the fate of ciprofloxacin, after concomitant administration with the aqueous leaf extract of Carica papaya, which herbal practitioners in Nigeria have found helpful in the treatment of painful crisis in sickle cell anaemia (SCA) patients. Method: Thirteen rabbits were fasted for 12 h and given by oral route ...

  19. Allelopathic Effects of Lantana (Lantana camara L.) Leaf Extracts on ...

    African Journals Online (AJOL)

    Bheema

    In contrast, tef plants had reduced root growth in various leaf extracts with the ... grows under a wide range of climate conditions and occurs on a variety of soil types ... prepared by soaking 100g fresh leaves of lantana with 500 ml distilled water .... Relative elongation ratio (RER) of root and shoot (percent of control) of three.

  20. Leaf Roof – designing luminescent solar concentrating PV roof tiles

    NARCIS (Netherlands)

    Reinders, A.H.M.E.; Doudart de la Grée, G.C.H.; Papadopoulos, A.; Rosemann, A.L.P.; Debije, M.G.; Cox, M.G.D.M.; Krumer, Z.

    2016-01-01

    The Leaf Roof project on the design features of PV roof tiles using Luminescent Solar Concentrator (LSC) technology has resulted in a functional prototype . The results are presented in the context of industrial product design with a focus on the aesthetic aspects of LSCs. This paper outlines the

  1. Leaf Roof - Designing Luminescent Solar Concentrating PV Roof Tiles

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; Doudart de la Gree, G.; Papadopoulos, A..; Rosemann, A.; Debije, M.G.; Cox, M.; Krumer, Zachar

    2016-01-01

    The Leaf Roof project on the design features of PV roof tiles using Luminescent Solar Concentrator (LSC) technology [1] has resulted in a functional prototype. The results are presented in the context of industrial product design with a focus on the aesthetic aspects of LSCs [2]. This paper outlines

  2. Antibacterial activity of root and leaf extracts of Jatropha zeyheri ...

    African Journals Online (AJOL)

    Acetone extract of the root exhibited minimal inhibitory concentration (MIC) of 0.39 mg/ml against Salmonella spp. followed by methanol and acetone extracts of the root (0.78 mg/ml) against Serratia marcescens. Methanol extract of the leaf exhibited MIC of 3.13 mg/ml against Staphylococcus aureus. This study validates the ...

  3. from an aqueous solution using Azadirachta indica leaf powder

    African Journals Online (AJOL)

    Azadirachta indica (neem) leaf powder was used as an adsorbent for the removal of textile dye from aqueous solution. The adsorption of dye on A. indica was found to be dependent on contact time, dye concentration and amount of adsorbent. Spectrophotometric technique was used for the measurement of concentration of ...

  4. Aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet ...

    African Journals Online (AJOL)

    We evaluated the effects of aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) on sodium arsenite-induced hepatotoxicity in Wistar rats. We observed that treatment of the animals with the extracts before or just after sodium arsenite administration significantly (p < 0.05) reduced mean liver and serum ...

  5. Cytotoxicity testing of aqueous extract of bitter leaf ( Vernonia ...

    African Journals Online (AJOL)

    Cytotoxicity testing of aqueous extract of bitter leaf ( Vernonia amygdalina Del ) and sniper 1000EC (2,3 dichlorovinyl dimethyl phosphate) using the Alium cepa ... 96 hours and EC50 values at 95% confidence interval was determined from a plot of root length against sample concentrations using Microsoft Excel software.

  6. Evaluation of anticonvulsant activity of methanol leaf extract of ...

    African Journals Online (AJOL)

    Hymenocardia acida is a plant used in African folkloric medicine in the treatment of headache, rheumatic pain, sickle cell crisis, malaria, epilepsy and cancer. This study was aimed at investigating the anticonvulsant potential of the methanol leaf extract of H. acida (MLEHA) in chicks and mice. Preliminary phytochemical ...

  7. Cassava Leaf Meal and Exogenous Enzyme as Supplements in ...

    African Journals Online (AJOL)

    %, 50% and 66.67% such that the levels of cassava leaf meal (CLM) supplementation were 5%, 7.5% and 10% but in addition Avizyme® (an exogenous commercial polysaccharidase) was added to the diets at the rate of 100g kg-1. The birds ...

  8. Leaf tissue assay for lepidopteran pests of Bt cotton

    Science.gov (United States)

    Laboratory measurements of susceptibility to Bt toxins can be a poor indicator of the ability of an insect to survive on transgenic crops. We investigated the potential of using cotton leaf tissue for evaluating heliothine susceptibilities to two dual-gene Bt cottons. A preliminary study was conduct...

  9. Nutritional evaluation of bitter leaf meal ( Vernonia amygdalina ...

    African Journals Online (AJOL)

    Nutritional evaluation of bitter leaf meal ( Vernonia amygdalina ): effects on ... A total of 72 one-day-old broiler chicks of Abor-acre breed were used for the trial and ... reduced the level of cholesterol, triglyceride, glucose, low density lipoprotein, ...

  10. Assessment of Toxicity Profile of Lasianthera Africana Leaf ...

    African Journals Online (AJOL)

    ALICE

    2015-04-15

    Apr 15, 2015 ... intraperitoneal, intravenous or intramuscular routes of .... Effect of oral administration of doses of Lasianthera africana leaf extract on body weight of normal rat ... drinking water and treated with metformin (anti-diabetic drug) at a dose level ... glucometer (One Touch Ultra 2 Blood Glucose Monitoring System,.

  11. A Conserved Molecular Framework for Compound Leaf Development

    DEFF Research Database (Denmark)

    Blein, Thomas; Pulido, Amada; Vialette-Guiraud, Aurélie

    2008-01-01

      Diversity in leaf shape is produced by alterations of the margin: for example, deep dissection leads to leaflet formation and less-pronounced incision results in serrations or lobes. By combining gene silencing and mutant analyses in four distantly related eudicot species, we show that reducing...

  12. Effects of Variety and Fungicidal Rate on Cercospora Leaf Spots ...

    African Journals Online (AJOL)

    Singh, V.R., Pandes, A.K., Reddy, P.M. and. Pao P.V. (1995). Resistance to Rust and Late leaf Spot of Groundnut. ICRISAT. Information Bulletin. No.47, Patancheru,. 502, 324, Andra Pradesh, India. P.24. Thapar, S., Bhusham, R. and Mathur, R.P.. (1995). Degradation of organophosphorus and carbamate pesticides in soils- ...

  13. Comparative Study of Root, Stalk and Leaf Essential Oils of ...

    African Journals Online (AJOL)

    MBI

    2017-03-03

    Mar 3, 2017 ... ABSTRACT. The root, stalk and leaf essential oils of Cymbopogon citratus grown in Kaduna, North Central Nigeria were extracted separately by hydrodistillation and characterized by GC-MS. The chemical composition analysis by. GC-MS of the oils allowed the identification of 34, 26 and 16 compounds ...

  14. Monosodium glutamate toxicity: Sida acuta leaf extract ameliorated ...

    African Journals Online (AJOL)

    The brain is reportedly sensitive to monosodium glutamate (MSG) toxicity via oxidative stress. Sida acuta leaf ethanolic extract (SALEE) possesses antioxidant activity which can mitigate this neurotoxicity. The present study investigated the possible protective effect of SALEE on MSG-induced toxicity in rats. Twenty-six ...

  15. Photosynthetic characterization of a rolled leaf mutant of rice ( Oryza ...

    African Journals Online (AJOL)

    A new rolling leaf rice mutant was identified which showed an apparently straighter longitudinal shape normal transverse rolling characters at all developing stages. The chlorophyll contents per fresh weight of this mutant leaves were lower than those of wild-type. The electron transfer rate (ETR) and photochemical ...

  16. Functional leaf attributes predict litter decomposition rate in herbaceous plants

    NARCIS (Netherlands)

    Cornelissen, J. H C; Thompson, K.

    1997-01-01

    We tested the hypothesis that functional attributes of living leaves provide a basis for predicting the decomposition rate of leaf litter. The data were obtained from standardized screening tests on 38 British herbaceous species. Graminoid monocots had physically tougher leaves with higher silicon

  17. Effects of Partial Replacement of Soybean Meal with Cassava Leaf ...

    African Journals Online (AJOL)

    One hundred and fifty (150) four weeks old broilers were raised in eight litter pens for the period of four weeks to observe the effect of cassava leaf meal (CLM) on the comparative body weight gain, feed intake, feed conversion ratio, feed efficiency and feed cost of the birds. Five experimental broiler finisher diets containing ...

  18. Anatomy of leaf and stem of Erythrina velutina

    Directory of Open Access Journals (Sweden)

    Márcia M. B. da Silva

    2013-04-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  19. Anatomy of leaf and stem of Erythrina velutina

    Directory of Open Access Journals (Sweden)

    Márcia M. B. da Silva

    2013-02-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  20. Extending Fluspect to simulate xanthophyll driven leaf reflectance dynamics

    Czech Academy of Sciences Publication Activity Database

    Vilfan, N.; Van der Tol, C.; Yang, P.; Wyber, R.; Malenovský, Zbyněk; Robinson, S. A.; Verhoef, A.

    2018-01-01

    Roč. 211, Jun (2018), s. 345-356 ISSN 0034-4257 Institutional support: RVO:86652079 Keywords : Fluspect * Leaf chlorophyll fluorescence * pri * Reflectance * scope * Xanthophyll cycle Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 6.265, year: 2016