WorldWideScience

Sample records for green leaf volatile

  1. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest.

    Science.gov (United States)

    Jardine, Kolby J; Chambers, Jeffrey Q; Holm, Jennifer; Jardine, Angela B; Fontes, Clarissa G; Zorzanelli, Raquel F; Meyers, Kimberly T; de Souza, Vinicius Fernadez; Garcia, Sabrina; Gimenez, Bruno O; Piva, Luani R de O; Higuchi, Niro; Artaxo, Paulo; Martin, Scot; Manzi, Antônio O

    2015-09-15

    Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV) emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C₅ and C₆ GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C₆ GLVs) were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress.

  2. WRKY40 and WRKY6 act downstream of the green leaf volatile E-2-hexenal in Arabidopsis

    NARCIS (Netherlands)

    Mirabella, R.; Rauwerda, H.; Allmann, S.; Scala, A.; Spyropoulou, E.A.; de Vries, M.; Boersma, M.R.; Breit, T.M.; Haring, M.A.; Schuurink, R.C.

    Plants are known to be responsive to volatiles, but knowledge about the molecular players involved in transducing their perception remains scarce. We study the response of Arabidopsis thaliana to E-2-hexenal, one of the green leaf volatiles (GLV) that is produced upon wounding, herbivory or

  3. Green Leaf Volatiles: A Plant’s Multifunctional Weapon against Herbivores and Pathogens

    Science.gov (United States)

    Scala, Alessandra; Allmann, Silke; Mirabella, Rossana; Haring, Michel A.; Schuurink, Robert C.

    2013-01-01

    Plants cannot avoid being attacked by an almost infinite number of microorganisms and insects. Consequently, they arm themselves with molecular weapons against their attackers. Plant defense responses are the result of a complex signaling network, in which the hormones jasmonic acid (JA), salicylic acid (SA) and ethylene (ET) are the usual suspects under the magnifying glass when researchers investigate host-pest interactions. However, Green Leaf Volatiles (GLVs), C6 molecules, which are very quickly produced and/or emitted upon herbivory or pathogen infection by almost every green plant, also play an important role in plant defenses. GLVs are semiochemicals used by insects to find their food or their conspecifics. They have also been reported to be fundamental in indirect defenses and to have a direct effect on pests, but these are not the only roles of GLVs. These volatiles, being probably one of the fastest weapons exploited, are also able to directly elicit or prime plant defense responses. Moreover, GLVs, via crosstalk with phytohormones, mostly JA, can influence the outcome of the plant’s defense response against pathogens. For all these reasons GLVs should be considered as co-protagonists in the play between plants and their attackers. PMID:23999587

  4. Green leaf volatiles: biosynthesis, biological functions and their applications in biotechnology.

    Science.gov (United States)

    ul Hassan, Muhammad Naeem; Zainal, Zamri; Ismail, Ismanizan

    2015-08-01

    Plants have evolved numerous constitutive and inducible defence mechanisms to cope with biotic and abiotic stresses. These stresses induce the expression of various genes to activate defence-related pathways that result in the release of defence chemicals. One of these defence mechanisms is the oxylipin pathway, which produces jasmonates, divinylethers and green leaf volatiles (GLVs) through the peroxidation of polyunsaturated fatty acids (PUFAs). GLVs have recently emerged as key players in plant defence, plant-plant interactions and plant-insect interactions. Some GLVs inhibit the growth and propagation of plant pathogens, including bacteria, viruses and fungi. In certain cases, GLVs released from plants under herbivore attack can serve as aerial messengers to neighbouring plants and to attract parasitic or parasitoid enemies of the herbivores. The plants that perceive these volatile signals are primed and can then adapt in preparation for the upcoming challenges. Due to their 'green note' odour, GLVs impart aromas and flavours to many natural foods, such as vegetables and fruits, and therefore, they can be exploited in industrial biotechnology. The aim of this study was to review the progress and recent developments in research on the oxylipin pathway, with a specific focus on the biosynthesis and biological functions of GLVs and their applications in industrial biotechnology. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  5. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

    Directory of Open Access Journals (Sweden)

    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  6. Aqueous Oxidation of Green Leaf Volatiles as a Source of Secondary Organic Aerosol

    Science.gov (United States)

    Richards-Henderson, N. K.; Hansel, A.; Pham, A. T.; Vempati, H. S.; Valsaraj, K. T.; Anastasio, C.

    2013-12-01

    Vegetation emits volatile oxygenated hydrocarbons - the green leaf volatiles (GLVs) - which are formed from the biochemical conversion of linoleic and linolenic acids within plant cells. Stress or damage to vegetation can significantly elevate emission fluxes of these compounds, some of which are fairly water soluble. Aqueous-phase reactions of the GLVs with photochemically generated oxidants - such as hydroxyl radical (OH), singlet oxygen (1O2) and excited triplet states of organic compounds (3C*) _ might then form low-volatility products that can act as secondary organic aerosol (SOA). In order to determine if GLVs can be a significant source of secondary organic carbon in fogwater, studies of GLVs in laboratory solutions are needed to elucidate the oxidation kinetics and the corresponding SOA mass yields. In this study we are determining the second-order rate constants, and SOA mass yields, for five GLVs (cis-3-hexen-1-ol, cis-3-hexenylacetate, methyl salicylate, methyl jasmonate, and 2-methyl-3-butene-2-ol) reacting with OH,1O2 and 3C*. Experiments are performed at relevant fog water pHs, temperatures, and oxidant concentrations. Rate constants are determined using a relative rate approach in which the decay of GLVs and reference compounds are monitored as function of time by HPLC. The capacity of GLVs to form aqueous SOA was determined by following the formation of their decomposition products with HPLC-UV/DAD and HPLC-ESI/MS. SOA mass yields are measured gravimetrically from laboratory solutions containing atmospherically relevant concentrations of photooxidants and GLVs, and irradiated with simulated sunlight. We will use our results to assess the potential contribution of aqueous GLV reactions as a source of SOA in cloudy or foggy atmospheres.

  7. Orchids mimic green-leaf volatiles to attract prey-hunting wasps for pollination.

    Science.gov (United States)

    Brodmann, Jennifer; Twele, Robert; Francke, Wittko; Hölzler, Gerald; Zhang, Qing-He; Ayasse, Manfred

    2008-05-20

    An outstanding feature of orchids is the diversity of their pollination systems [1]. Most remarkable are those species that employ chemical deceit for the attraction of pollinators [2]. The orchid Epipactis helleborine is a typical wasp flower, exhibiting physiological and morphological adaptations for the attraction of pollinating social wasps [3]. As noted by Darwin [1], this species is almost entirely overlooked by other potential pollinators, despite a large nectar reward. Therefore, the mechanism for the attraction of pollinating social wasps was something of a mystery. By using a combination of behavioral experiments, electrophysiological investigations, and chemical analyses, we demonstrate for the first time that the flowers of E. helleborine and E. purpurata emit green-leaf volatiles (GLVs), which are attractive to foragers of the social wasps Vespula germanica and V. vulgaris. GLVs, emitted by damaged plant tissues, are known to guide parasitic wasps to their hosts [4]. Several E. helleborine GLVs that induced response in the antennae of wasps were also emitted by cabbage leaves infested with caterpillars (Pieris brassicae), which are common prey items for wasps [5]. This is the first example in which GLVs have been implicated in chemical mimicry for the attraction of pollinating insects.

  8. Green leaf volatiles and oxygenated metabolite emission bursts from mesquite branches following light-dark transitions.

    Science.gov (United States)

    Jardine, K; Barron-Gafford, G A; Norman, J P; Abrell, L; Monson, R K; Meyers, K T; Pavao-Zuckerman, M; Dontsova, K; Kleist, E; Werner, C; Huxman, T E

    2012-09-01

    Green leaf volatiles (GLVs) are a diverse group of fatty acid-derived compounds emitted by all plants and are involved in a wide variety of developmental and stress-related biological functions. Recently, GLV emission bursts from leaves were reported following light-dark transitions and hypothesized to be related to the stress response while acetaldehyde bursts were hypothesized to be due to the 'pyruvate overflow' mechanism. In this study, branch emissions of GLVs and a group of oxygenated metabolites (acetaldehyde, ethanol, acetic acid, and acetone) derived from the pyruvate dehydrogenase (PDH) bypass pathway were quantified from mesquite plants following light-dark transitions using a coupled GC-MS, PTR-MS, and photosynthesis system. Within the first minute after darkening following a light period, large emission bursts of both C(5) and C(6) GLVs dominated by (Z)-3-hexen-1-yl acetate together with the PDH bypass metabolites are reported for the first time. We found that branches exposed to CO(2)-free air lacked significant GLV and PDH bypass bursts while O(2)-free atmospheres eliminated the GLV burst but stimulated the PDH bypass burst. A positive relationship was observed between photosynthetic activity prior to darkening and the magnitude of the GLV and PDH bursts. Photosynthesis under (13)CO(2) resulted in bursts with extensive labeling of acetaldehyde, ethanol, and the acetate but not the C(6)-alcohol moiety of (Z)-3-hexen-1-yl acetate. Our observations are consistent with (1) the "pyruvate overflow" mechanism with a fast turnover time (3 h) responsible for the C(6) alcohol moiety of (Z)-3-hexen-1-yl acetate via the 13-lipoxygenase pathway. We conclude that our non-invasive method may provide a new valuable in vivo tool for studies of acetyl-CoA and fatty acid metabolism in plants at a variety of spatial scales.

  9. Reactive oxidation products promote secondary organic aerosol formation from green leaf volatiles

    Directory of Open Access Journals (Sweden)

    J. F. Hamilton

    2009-06-01

    Full Text Available Green leaf volatiles (GLVs are an important group of chemicals released by vegetation which have emission fluxes that can be significantly increased when plants are damaged or stressed. A series of simulation chamber experiments has been conducted at the European Photoreactor in Valencia, Spain, to investigate secondary organic aerosol (SOA formation from the atmospheric oxidation of the major GLVs cis-3-hexenylacetate and cis-3-hexen-1-ol. Liquid chromatography-ion trap mass spectrometry was used to identify chemical species present in the SOA. Cis-3-hexen-1-ol proved to be a more efficient SOA precursor due to the high reactivity of its first generation oxidation product, 3-hydroxypropanal, which can hydrate and undergo further reactions with other aldehydes resulting in SOA dominated by higher molecular weight oligomers. The lower SOA yields produced from cis-3-hexenylacetate are attributed to the acetate functionality, which inhibits oligomer formation in the particle phase. Based on observed SOA yields and best estimates of global emissions, these compounds may be calculated to be a substantial unidentified global source of SOA, contributing 1–5 TgC yr−1, equivalent to around a third of that predicted from isoprene. Molecular characterization of the SOA, combined with organic mechanistic information, has provided evidence that the formation of organic aerosols from GLVs is closely related to the reactivity of their first generation atmospheric oxidation products, and indicates that this may be a simple parameter that could be used in assessing the aerosol formation potential for other unstudied organic compounds in the atmosphere.

  10. Molecular modeling of the green leaf volatile methyl salicylate on atmospheric air/water interfaces.

    Science.gov (United States)

    Liyana-Arachchi, Thilanga P; Hansel, Amie K; Stevens, Christopher; Ehrenhauser, Franz S; Valsaraj, Kalliat T; Hung, Francisco R

    2013-05-30

    Methyl salicylate (MeSA) is a green leaf volatile (GLV) compound that is emitted in significant amounts by plants, especially when they are under stress conditions. GLVs can then undergo chemical reactions with atmospheric oxidants, yielding compounds that contribute to the formation of secondary organic aerosols (SOAs). We investigated the adsorption of MeSA on atmospheric air/water interfaces at 298 K using thermodynamic integration (TI), potential of mean force (PMF) calculations, and classical molecular dynamics (MD) simulations. Our molecular models can reproduce experimental results of the 1-octanol/water partition coefficient of MeSA. A deep free energy minimum was found for MeSA at the air/water interface, which is mainly driven by energetic interactions between MeSA and water. At the interface, the oxygenated groups in MeSA tend to point toward the water side of the interface, with the aromatic group of MeSA lying farther away from water. Increases in the concentrations of MeSA lead to reductions in the height of the peaks in the MeSA-MeSA g(r) functions, a slowing down of the dynamics of both MeSA and water at the interface, and a reduction in the interfacial surface tension. Our results indicate that MeSA has a strong thermodynamic preference to remain at the air/water interface, and thus chemical reactions with atmospheric oxidants are more likely to take place at this interface, rather than in the water phase of atmospheric water droplets or in the gas phase.

  11. Olfactory responses of Plutella xylostella natural enemies to host pheromone, larval frass, and green leaf cabbage volatiles.

    Science.gov (United States)

    Reddy, G V P; Holopainen, J K; Guerrero, A

    2002-01-01

    The parasitoids Trichogramma chilonis (Hymenoptera: Trichogrammatidae) and Cotesia plutellae (Hymenoptera: Braconidae), and the predator Chrysoperla carnea (Neuroptera: Chrysopidae), are potential biological control agents for the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae). We present studies on the interactions between these bioagents and various host-associated volatiles using a Y olfactometer. T chilonis was attracted to a synthetic pheromone blend (Z11-16:Ald, Z11-16:Ac, and Z11-16:OH in a 1:1:0.01 ratio), to Z11-16:Ac alone, and to a 1:1 blend of Z11-16:Ac and Z11-16:Ald. C. plutellae responded to the blend and to Z11-16:Ac and Z11-16:Ald. Male and female C. carnea responded to the blend and to a 1:1 blend of the major components of the pheromone, although no response was elicited by single compounds. Among the four host larval frass volatiles tested (dipropyl disulfide, dimethyl disulfide, allyl isothiocyanate, and dimethyl trisulfide), only allyl isothiocyanate elicited significant responses in the parasitoids and predator, but C. plutellae and both sexes of C. carnea did respond to all four volatiles. Among the green leaf volatiles of cabbage (Brassica oleracea subsp. capitata), only Z3-6:Ac elicited significant responses from T. chilonis, C. plutellae, and C. carnea, but C. plutellae also responded to E2-6:Ald and Z3-6:OH. When these volatiles were blended with the pheromone, the responses were similar to those elicited by the pheromone alone, except for C. carnea males, which had an increased response. The effect of temperature on the response of the biological agents to a mixture of the pheromone blend and Z3-6:Ac was also studied. T. chilonis was attracted at temperatures of 25-35 degrees C, while C. plutellae and C. carnea responded optimally at 30-35 degrees C and 20-25 degrees C, respectively. These results indicate that the sex pheromone and larval frass volatiles from the diamondback moth, as well as volatile compounds from

  12. Impact of heat stress on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

    Science.gov (United States)

    Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

    2012-07-01

    Changes in the biogenic volatile organic compound (BVOC) emissions from European beech, Palestine oak, Scots pine, and Norway spruce exposed to heat stress were measured in a laboratory setup. In general, heat stress decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. Decreasing emission strength with heat stress was independent of the tree species and whether the de novo emissions being constitutive or induced by biotic stress. In contrast, heat stress induced emissions of green leaf volatiles. It also amplified the release of monoterpenes stored in resin ducts of conifers probably due to heat-induced damage of these resin ducts. The increased release of monoterpenes could be strong and long lasting. But, despite of such strong monoterpene emission pulses, the net effect of heat stress on BVOC emissions from conifers can be an overall decrease. In particular during insect attack on conifers the plants showed de novo emissions of sesquiterpenes and phenolic BVOC which exceeded constitutive monoterpene emissions from pools. The heat stress induced decrease of these de novo emissions was larger than the increased release caused by damage of resin ducts. We project that global change induced heat waves may cause increased BVOC emissions only in cases where the respective areas are predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOC. Otherwise the overall effect of heat stress will be a decrease in BVOC emissions.

  13. Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

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    E. Kleist

    2012-12-01

    Full Text Available Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress on plants changing emissions of biogenic volatile organic compounds (BVOCs. As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress.

    In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease.

    Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do

  14. Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles.

    Science.gov (United States)

    Li, Pengyan; Zhu, Junwei; Qin, Yuchuan

    2012-08-01

    Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most serious pests of Brassicaceae crops worldwide. Electrophysiological and behavioral responses of P. xylostella to green leaf volatiles (GLVs) alone or together with its female sex pheromone were investigated in laboratory and field. GLVs 1-hexanol and (Z)-3-hexen-1-ol elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relatively weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactometer experiments. (E)-2-Hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate induced attraction of males, reaching up to 50%, significantly higher than the response to the unbaited control arm. In field experiments conducted in 2008 and 2009, significantly more moths were captured in traps baited with synthetic sex pheromone with either (Z)-3-hexenyl acetate alone or a blend of (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, and (E)-2-hexenal compared with sex pheromone alone and other blend mixtures. These results demonstrated that GLVs could be used to enhance the attraction of P. xylostella males to sex pheromone-baited traps.

  15. Behavioral responses of the diamondback moth, Plutella xylostella, to green leaf volatiles of Brassica oleracea subsp. capitata.

    Science.gov (United States)

    Reddy, G V; Guerrero, A

    2000-12-01

    Green leaf volatiles (GLVs) from Brassica oleracea subsp. capitata L. have been identified as 1-hexanol, (Z)-3-hexen-1-ol, 1-hexen-3-ol, hexanal, (E)-2-hexenal, hexyl acetate, and (Z)-3-hexenyl acetate, by their mass spectra and retention times in comparison with authentic samples. No isothiocyanates were found in the extract. The activity of these chemicals has been determined on mated and unmated males and females of the diamondback moth (DBM) Plutella xylostella in the laboratory (wind tunnel) and in the field. On unmated males, mixtures of (Z)-3-hexenyl acetate, (E)-2-hexenal, and (Z)-3-hexen-1-ol with the pheromone induced attractant/arresting behavior in 80-100% of the males tested, significantly higher than the effect induced by the pheromone alone. On mated males and unmated females the effect of the GLVs alone or in combination with the pheromone was poor, while on mated females these compounds elicited upwind flight and arresting behavior in 40-60% of the females assayed. There was no synergism when these chemicals were mixed with the pheromone. In the field, (Z)-3-hexenyl acetate, the most active GLV in laboratory tests, when mixed with the pheromone in 1:1 ratio, enhanced 6-7-fold the number of females and 20-30% the number of males caught by traps over those baited with the pheromone alone. Our results indicate that the enhancement of the attraction of both males and females of the DBM to traps baited with pheromone blended with the relatively inexpensive and environmentally safe (Z)-3-hexenyl acetate may be important for future control strategies of the pest.

  16. Early transcriptome analyses of Z-3-Hexenol-treated zea mays revealed distinct transcriptional networks and anti-herbivore defense potential of green leaf volatiles.

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    Jurgen Engelberth

    Full Text Available Green leaf volatiles (GLV, which are rapidly emitted by plants in response to insect herbivore damage, are now established as volatile defense signals. Receiving plants utilize these molecules to prime their defenses and respond faster and stronger when actually attacked. To further characterize the biological activity of these compounds we performed a microarray analysis of global gene expression. The focus of this project was to identify early transcriptional events elicited by Z-3-hexenol (Z-3-HOL as our model GLV in maize (Zea mays seedlings. The microarray results confirmed previous studies on Z-3-HOL -induced gene expression but also provided novel information about the complexity of Z-3-HOL -induced transcriptional networks. Besides identifying a distinct set of genes involved in direct and indirect defenses we also found significant expression of genes involved in transcriptional regulation, Ca(2+-and lipid-related signaling, and cell wall reinforcement. By comparing these results with those obtained by treatment of maize seedlings with insect elicitors we found a high degree of correlation between the two expression profiles at this early time point, in particular for those genes related to defense. We further analyzed defense gene expression induced by other volatile defense signals and found Z-3-HOL to be significantly more active than methyl jasmonate, methyl salicylate, and ethylene. The data presented herein provides important information on early genetic networks that are activated by Z-3-HOL and demonstrates the effectiveness of this compound in the regulation of typical plant defenses against insect herbivores in maize.

  17. Aqueous-phase oxidation of green leaf volatiles by hydroxyl radical as a source of SOA: Product identification from methyl jasmonate and methyl salicylate oxidation

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    Hansel, Amie K.; Ehrenhauser, Franz S.; Richards-Henderson, Nicole K.; Anastasio, Cort; Valsaraj, Kalliat T.

    2015-02-01

    Green leaf volatiles (GLVs) are a group of biogenic volatile organic compounds (BVOCs) released into the atmosphere by vegetation. BVOCs produce secondary organic aerosol (SOA) via gas-phase reactions, but little is known of their aqueous-phase oxidation as a source of SOA. GLVs can partition into atmospheric water phases, e.g., fog, mist, dew or rain, and be oxidized by hydroxyl radicals (˙OH). These reactions in the liquid phase also lead to products that have higher molecular weights, increased polarity, and lower vapor pressures, ultimately forming SOA after evaporation of the droplet. To examine this process, we investigated the aqueous, ˙OH-mediated oxidation of methyl jasmonate (MeJa) and methyl salicylate (MeSa), two GLVs that produce aqueous-phase SOA. High performance liquid chromatography/electrospray ionization mass spectrometry (HPLC-ESI-MS) was used to monitor product formation. The oxidation products identified exhibit higher molecular mass than their parent GLV due to either dimerization or the addition of oxygen and hydroxyl functional groups. The proposed structures of potential products are based on mechanistic considerations combined with the HPLC/ESI-MS data. Based on the structures, the vapor pressure and the Henry's law constant were estimated with multiple methods (SPARC, SIMPOL, MPBPVP, Bond and Group Estimations). The estimated vapor pressures of the products identified are significantly (up to 7 orders of magnitude) lower than those of the associated parent compounds, and therefore, the GLV oxidation products may remain as SOA after evaporation of the water droplet. The contribution of the identified oxidation products to SOA formation is estimated based on measured HPLC-ESI/MS responses relative to previous aqueous SOA mass yield measurements.

  18. 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

  19. VOLATILE LEAF OIL CONSTITUENTS OF OCIMUM AMERICANUM ...

    African Journals Online (AJOL)

    Steam distilled volatile oils from the leaves of Ocimum americanum L. growing in Western Kenya were analysed by GC and GC-MS. A total of 36 compounds, representing a total of 88.51% of the total oil, were identified. The oil was classified as terpinen-4-ol-type according to the terpinen-4-ol content (43.21%). To the best ...

  20. Evaluation of γ-radiation on green tea odor volatiles

    International Nuclear Information System (INIS)

    Fanaro, G.B.; Duarte, R.C.; Araujo, M.M.; Purgatto, E.; Villavicencio, A.L.C.H.

    2011-01-01

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  1. Composition of the volatile fraction of a sample of Brazilian green propolic and its phytotoxic activity.

    Science.gov (United States)

    Fernandes-Silva, Caroline C; Lima, Carolina A; Negri, Giuseppina; Salatino, Maria L F; Salatino, Antonio; Mayworm, Marco A S

    2015-12-01

    Propolis is a resinous material produced by honeybees, containing mainly beeswax and plant material. Despite the wide spectrum of biological activity of propolis, to our knowledge no studies have been carried out about phytotoxic properties of Brazilian propolis and its constituents. The aims of this study were to analyze the chemical composition and to evaluate the phytotoxic activity of the volatile fraction of a sample of Brazilian green propolis. Main constituents are the phenylpropanoid 3-prenylcinnamic acid allyl ester (26.3%) and the sesquiterpene spathulenol (23.4%). Several other sesquiterpenes and phenylpropanoids, in addition to linalool and α-terpineol (monoterpenes), were also detected. The activity of solutions of the volatile fraction at 1.0, 0.5 and 0.1% was tested on lettuce seeds and seedlings. The solution at 1% inhibited completely the seed germination and solutions at 0.1 and 0.5% reduced the germination rate index. The solution at 0.5% reduced the growth of the hypocotyl-radicle axis and the development of the cotyledon leaf. The chemical composition of the volatile fraction of this Brazilian green propolis is different from those previously described, and these results may contribute to a better understanding about the chemical variations in propolis. The volatile fraction of Brazilian green propolis influences both germination of seed lettuce and the growth of its seedlings, showing an phytotoxic potential. © 2014 Society of Chemical Industry.

  2. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    Science.gov (United States)

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  3. Price volatility and banking in green certificate markets

    DEFF Research Database (Denmark)

    Amundsen, Eirik Schrøder; Baldursson, Fridrik M.; Mortensen, Jørgen Birk

    2006-01-01

    the paper shows that the introduction of banking of GCs may reduce price volatility considerably and lead to increased social surplus. Banking lowers average prices and is therefore not necessarily to the benefit of 'green producers'. Prooposed price bounds on GC-prices will reduce the importance of banking...

  4. Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-12-01

    The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

  5. Are bursts of green leaf volatile emissions from plants following light to dark transitions associated with de-novo biosynthesis of free fatty acids and not stress-induced membrane degradation? J. Norman- University of North Carolina K. Jardine- University of Arizona G. Barron-Gafford- University of Arizona

    Science.gov (United States)

    Norman, J. P.; Jardine, K. J.; Barron-Gafford, G. A.

    2011-12-01

    Green Leaf Volatiles (GLVs) are a diverse group of fatty acid-derived Volatile Organic Compounds (VOCs) emitted by all plants. These GLVs are involved in a wide variety of stress-related biological functions, as well as the formation of secondary organic aerosols and ozone in the troposphere. To date, GLV emissions have primarily been associated with acute stress responses wherein fatty acids are released from plant membranes and enzymatically oxidized to GLVs via the lipoxygenase pathway. However the biochemical role of these gases within unwounded plants has remained unknown so far. Recently, GLV emissions were reported following light-dark transitions and were hypothesized to also be related to a mechanical stress response (i.e. leaf cutting). However in this study we show that GLV emissions from mesquite trees have a separate biochemical pathway for their production that is unrelated to stress. GLV emission rates following light-dark transitions were quantified from young and mature Mesquite branches. It was found that young branches had very high photosynthetic rates and displayed strong bursts of a wide array of GLVs following darkening, while mature branches had much lower photosynthetic rates showed much weaker or no bursts. This is interesting because neither the mature nor the juvenile plants were subjected to any type of stress during measurement. Moreover, the older plant samples (which had the lower emissions) were collected by clipping branches from a tree and re-clipping their stems under water. Given what has previously been established concerning the relationship of GLV emissions to mechanical stress, one would expect these older branches to have higher emissions than their juvenile counterparts rather than lower emissions. We speculate that the emission of GLVs during light-dark transitions is not the result of a stress response, but rather the result of rapid de-novo fatty acid biosynthesis occurring in chloroplasts of young branches fed by a

  6. Formation of adventitious roots on green leaf cuttings of Phaseolus vulgaris L.

    NARCIS (Netherlands)

    Oppenoorth, Johanna Margriet

    1980-01-01

    n this thesis the development of adventitious roots on green leaf cuttings of Phaseolus vulgaris L. is studies. The use of green leaf cuttings has the advantage that the leaf blade provides the developing roots inthe petiole with all the nutrients required, a disadvantage is that the composition of

  7. Evaluation of Volatile Species in Green Monopropellant Project

    Science.gov (United States)

    Greene, Benjamin

    2015-01-01

    NASA is interested in green monopropellants to replace hydrazine in reaction control systems (RCSs). Some current NASA programs require reduced vapor pressure and low toxicity monopropellant (green) and superior performance (specific impulse and density) formulations. Earlier vapor phase studies of a candidate green monopropellant at the NASA White Sands Test Facility (WSTF) showed the presence of a volatile species that warranted further investigation. The purpose of this study was to further characterize the volatile species and to evaluate it. The evaluation was with respect to whether the volatile species was an impurity or how it is formed, and to use that information to examine whether its presence as an impurity can be eliminated during formulation. The evaluation also considered whether formation of the volatile impurity could be prevented while not compromising the propellant. To reduce variables associated with evaluation of the propellant formulation as a whole, a precursor to one of the individual components in the propellant formulation was subjected to a NASA Standard 6001B Flammability, Off-gassing, and Compatibility Requirements and Test Procedures "Determination of Off-gassed Products (Test 7)". Testing took place in the NASA WSTF Molecular Desorption and Analysis Laboratory. One gram of the precursor was placed in a flask within a specimen container. After thermal conditioning for 72 +/- 1 h at 50 +/- 3 deg C (122 +/- 5 deg F), the atmosphere inside the specimen container was analyzed for off-gassed compounds by cryotrap gas chromatography-mass spectrometry (GC-MS) and fixed sample loop GC-flame ionization detection (GC-FID). The specimen container used was glass to minimize potential catalytic surfaces. The identification of compounds was difficult due to the complexity of the vapor phase concentrations and overlapping chromatographic peaks and mass spectra. However, eleven compounds were specifically identified and five compounds or classes of

  8. Drought and leaf herbivory influence floral volatiles and pollinator attraction

    Science.gov (United States)

    Laura A. Burkle; Justin B. Runyon

    2016-01-01

    The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

  9. Volatile constituents and biological activities of the leaf and root of Echinacea species from South Africa

    Directory of Open Access Journals (Sweden)

    M. Nyalambisa

    2017-03-01

    It is concluded that root and leaf of this Echinacea species contain volatile oils which varied in their yield and chemical compositions. The essential root oil is non-toxic orally and it demonstrated significant anti-inflammatory and analgesic activities in laboratory animals.

  10. Estimation of leaf area index in cereal crops using red-green images

    DEFF Research Database (Denmark)

    Kirk, Kristian; Andersen, Hans Jørgen; Thomsen, Anton G

    2009-01-01

    A new method for estimating the leaf area index (LAI) in cereal crops based on red-green images taken from above the crop canopy is introduced. The proposed method labels pixels into vegetation and soil classes using a combination of greenness and intensity derived from the red and green colour b...

  11. Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae).

    Science.gov (United States)

    Malheiro, Ricardo; Casal, Susana; Cunha, Sara C; Baptista, Paula; Pereira, José Alberto

    2016-01-01

    The olive fly, Bactrocera oleae (Rossi), is a monophagous pest that displays an oviposition preference among cultivars of olive (Olea europaea L.). To clarify the oviposition preference, the olive leaf volatiles of three olive cultivars (Cobrançosa, Madural and Verdeal Transmontana) were assessed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) at six different periods of olive fruit maturation and degrees of infestation. A total of 39 volatiles were identified, mainly esters and alcohols, with a minor percentage of aldehydes, ketones and terpenic compounds, including sesquiterpenes. At sampling dates with higher degrees of infestation, cv. Cobrançosa had, simultaneously, significantly lower infestation degrees and higher volatile amounts than the other two cultivars, with a probable deterrent effect for oviposition. The green leaf volatiles (GLVs) (Z)-3-hexen-1-ol and (Z)-3-hexen-1-ol acetate) were the main compounds identified in all cultivars, together with toluene. The abundance of GLVs decreased significantly throughout maturation, without significant differences among cultivars, while toluene showed a general increase and positive correlation with olive fly infestation levels. The results obtained could broaden our understanding of the roles of various types and amounts of olive volatiles in the environment, especially in olive fly host selection and cultivar preference. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effect of extraction time on antioxidants and bioactive volatile components of green tea (Camellia sinensis, using GC/MS

    Directory of Open Access Journals (Sweden)

    Mudasir Ahmad

    2015-12-01

    Full Text Available Two green tea types, leaf grade and sanding, were extracted at different time intervals: 20, 40, and 120 min at a constant temperature of 50°C. The extracts were analyzed by GC/MS technique. The major compounds identified were myristic acid, palmitic acid, stearic acid, oleic acid, 1H-purine-2,6-dione, caffeine, linoleic acid, diethyl ester, and 1H-purine-6-amine. Stearic acid, palmitic acid, linoleic acid, and myristic acid were more abundantly present in the leaf-grade variety than sanding. However, some levels of acetic acid, cyclobutanol, hexadecanoic acid, octadecanoic acid, 9-octadecenoic acid, and caffeine were also found in both the tea types. Most of the volatile compounds were detected between 20–40-min time of extraction. The 40-min time of extraction also showed the maximum content of polyphenols and antioxidants in both the tea types. Thus, 40 min was suggested as the most suitable time for maximum extraction of bioactive volatiles, antioxidants, and polyphenols from green tea.

  13. Leaf development and photosynthetic properties of three tropical tree species with delayed greening

    NARCIS (Netherlands)

    Cai, Z.Q.; Slot, M.; Fan, Z.X.

    2005-01-01

    Leaf developmental patterns were characterized for three tropical tree species with delayed greening. Changes in the pigment contents, photosynthetic capacity, stomata development, photosystem 2 efficiency, rate of energy dissipation, and the activity of partial protective enzymes were followed in

  14. Green synthesis of CuO nanoparticles using Cassia auriculata leaf ...

    African Journals Online (AJOL)

    Purpose: To undertake green synthesis of copper oxide nanoparticles (CuO NPs) using Cassia auriculata leaf extract ... Several methods are available for CuO NP preparation ... reader. Characterization .... would be important targets in current.

  15. Trapping female Pandemis limitata (Lepidoptera: Tortricidae) moths with mixtures of acetic acid, benzenoid apple leaf volatiles, and sex pheromones

    Science.gov (United States)

    Pandemis limitata (Robinson) is one of several leaf-feeding caterpillar pests of commercial tree-fruit crops in British Columbia. Recent discovery that European Pandemis spp. are attracted to lures containing acetic acid (AA) and caterpillar-induced benzenoid apple leaf volatiles, 2-phenylethanol a...

  16. Estimating the total leaf area of the green dwarf coconut tree (Cocos nucifera L.

    Directory of Open Access Journals (Sweden)

    Sousa Elias Fernandes de

    2005-01-01

    Full Text Available Leaf area has significant effect on tree transpiration, and its measurement is important to many study areas. This work aimed at developing a non-destructive, practical, and empirical method to estimate the total leaf area of green dwarf coconut palms (Cocos nucifera L. in plantations located at the northern region of Rio de Janeiro state, Brazil. A mathematical model was developed to estimate total leaf area values (TLA as function of the average lengths of the last three leaf raquis (LR3, and of the number of leaves in the canopy (NL. The model has satisfactory degree of accuracy for agricultural engineering purposes.

  17. Estimation of leaf area index in cereal crops using red–green images

    DEFF Research Database (Denmark)

    Nielsen, Kristian Kirk; Andersen, Hans Jørgen; Thomsen, Anton

    2009-01-01

    A new method for estimating the leaf area index (LAI) in cereal crops based on red–green images taken from above the crop canopy is introduced. The proposed method labels pixels into vegetation and soil classes using a combination of greenness and intensity derived from the red and green colour b....... Conclusions Acknowledgements Appendix. Modelling the correlation between greenness and brightness References   Fig. 1. Simulated image of a vegetation canopy (left), with distribution of pixel greenness and brightness (right). View Within Article...

  18. Differential Contribution of Jasmine Floral Volatiles to the Aroma of Scented Green Tea

    Directory of Open Access Journals (Sweden)

    Jian-Xia Shen

    2017-01-01

    Full Text Available Tea volatiles’ generation and retention over manufacturing processes are crucial for tea quality. In this study, floral volatile adsorption and retention in green tea scented with Jasminum sambac flowers were examined over the scenting process. Out of 34 enhanced volatiles in the scented tea, β-ionone, β-linalool, indole, and methyl anthranilate were the most potent odorants with 5.1–45.2-fold higher odor activity values than the corresponding controls in the nonscented tea. Scenting efficiencies for the floral volatiles retained in the scented tea (the percentage of volatile abundance over its corresponding amount in jasmine flowers ranged from 0.22% for α-farnesene to 75.5% for β-myrcene. Moreover, due to additional rounds of heat treatment for scented green tea manufacturing, some volatiles such as carotenoid-derived geraniol and β-ionone and lipid-derived (Z-jasmone were heat-enhanced and others such as nonanal were heat-desorbed in the scented green tea. Our study revealed that dynamic volatile absorption and desorption collectively determined tea volatile retention and tea aroma. Our findings may have a great potential for practical improvement of tea aroma.

  19. Ammonia volatilization from crop residues and frozen green manure crops

    Science.gov (United States)

    de Ruijter, F. J.; Huijsmans, J. F. M.; Rutgers, B.

    2010-09-01

    Agricultural systems can lose substantial amounts of nitrogen (N). To protect the environment, the European Union (EU) has adopted several directives that set goals to limit N losses. National Emission Ceilings (NEC) are prescribed in the NEC directive for nitrogen oxides and ammonia. Crop residues may contribute to ammonia volatilization, but sufficient information on their contribution to the national ammonia volatilization is lacking. Experiments were carried out with the aim to assess the ammonia volatilization of crop residues left on the soil surface or incorporated into the soil under the conditions met in practice in the Netherlands during late autumn and winter. Ammonia emission from residues of broccoli, leek, sugar beet, cut grass, fodder radish (fresh and frozen) and yellow mustard (frozen) was studied during two winter seasons using volatilization chambers. Residues were either placed on top of soil or mixed with soil. Mixing residues with soil gave insignificant ammonia volatilization, whereas volatilization was 5-16 percent of the N content of residues when placed on top of soil. Ammonia volatilization started after at least 4 days. Total ammonia volatilization was related to C/N-ratio and N concentration of the plant material. After 37 days, cumulative ammonia volatilization was negligible from plant material with N concentration below 2 percent, and was 10 percent of the N content of plant material with 4 percent N. These observations can be explained by decomposition of plant material by micro-organisms. After an initial built up of the microbial population, NH 4+ that is not needed for their own growth is released and can easily emit as NH 3 at the soil surface. The results of the experiments were used to estimate the contribution of crop residues to ammonia volatilization in the Netherlands. Crop residues of arable crops and residues of pasture topping may contribute more than 3 million kg NH 3-N to the national ammonia volatilization of the

  20. Weeding volatiles reduce leaf and seed damage to field-grown soybeans and increase seed isoflavones.

    Science.gov (United States)

    Shiojiri, Kaori; Ozawa, Rika; Yamashita, Ken-Ichi; Uefune, Masayoshi; Matsui, Kenji; Tsukamoto, Chigen; Tokumaru, Susumu; Takabayashi, Junji

    2017-01-30

    Field experiments were conducted over 3 years (2012, 2013, and 2015), in which half of the young stage soybean plants were exposed to volatiles from cut goldenrods three times over 2-3 weeks, while the other half remained unexposed. There was a significant reduction in the level of the total leaf damage on exposed soybean plants compared with unexposed ones. In 2015, the proportion of damage to plants by Spodoptera litura larvae, a dominant herbivore, was significantly less in the exposed field plots than in the unexposed plots. Under laboratory conditions, cut goldenrod volatiles induced the direct defenses of soybean plants against S. litura larvae and at least three major compounds, α-pinene, β-myrcene, and limonene, of cut goldenrod volatiles were involved in the induction. The number of undamaged seeds from the exposed plants was significantly higher than that from unexposed ones. Concentrations of isoflavones in the seeds were significantly higher in seeds from the exposed plants than in those from the unexposed plants. Future research evaluating the utility of weeding volatiles, as a form of plant-plant communications, in pest management programs is necessary.

  1. Lethal concentration of carbofuran to brown planthopper (Nilaparvata lugens) and green leaf-hopper (Nephotettix virecence)

    International Nuclear Information System (INIS)

    Kuswadi, A.N.; Sumatra, M.; Anwar, E.; Soekarna, D.

    1988-01-01

    An oral toxicity test of carbofuran to brown planthopper and green leaf-hopper using sucrose solution as feed given to the hopper through a membrane feeding system was conducted in the laboratory, pure carbofuran was dilute in the feeding solution. The 50 percent lethal concentration (LC-50) of this insecticide to adult and nymph of brown planthopper were 0.21 and 0.43 ppm, respectively, while those to adult and nymph of green leaf-hopper were 0.43 and 0.58 ppm. The LC 90 were 0.56 an 0.90 ppm to adult and nymph of brown planthopper, and 1.20 and 1.60 ppm to adult and nymph of green leaf-hopper, respectively. The brown planthopper was found to be more susceptible than the nymph. When carbofuran was applied to rice plant, this insecticide was accumulated more in the leaf than in the stem, so that green leaf-hopper got more toxicity than the brown planthopper. (authors). 5 refs, 7 figs

  2. Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages

    Science.gov (United States)

    Mozaffar, A.; Schoon, N.; Bachy, A.; Digrado, A.; Heinesch, B.; Aubinet, M.; Fauconnier, M.-L.; Delaplace, P.; du Jardin, P.; Amelynck, C.

    2018-03-01

    Plants are the major source of Biogenic Volatile Organic Compounds (BVOCs) which have a large influence on atmospheric chemistry and the climate system. Therefore, understanding of BVOC emissions from all abundant plant species at all developmental stages is very important. Nevertheless, investigations on BVOC emissions from even the most widespread agricultural crop species are rare and mainly confined to the healthy green leaves. Senescent leaves of grain crop species could be an important source of BVOCs as almost all the leaves senesce on the field before being harvested. For these reasons, BVOC emission measurements have been performed on maize (Zea mays L.), one of the most cultivated crop species in the world, at all the leaf developmental stages. The measurements were performed in controlled environmental conditions using dynamic enclosures and proton transfer reaction mass spectrometry (PTR-MS). The main compounds emitted by senescent maize leaves were methanol (31% of the total cumulative BVOC emission on a mass of compound basis) and acetic acid (30%), followed by acetaldehyde (11%), hexenals (9%) and m/z 59 compounds (acetone/propanal) (7%). Important differences were observed in the temporal emission profiles of the compounds, and both yellow leaves during chlorosis and dry brown leaves after chlorosis were identified as important senescence-related BVOC sources. Total cumulative BVOC emissions from senescent maize leaves were found to be among the highest for senescent Poaceae plant species. BVOC emission rates varied strongly among the different leaf developmental stages, and senescent leaves showed a larger diversity of emitted compounds than leaves at earlier stages. Methanol was the compound with the highest emissions for all the leaf developmental stages and the contribution from the young-growing, mature, and senescent stages to the total methanol emission by a typical maize leaf was 61, 13, and 26%, respectively. This study shows that BVOC

  3. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the substantiation of a health claim related to a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden Swiss chard

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden Swiss chard and white Swiss chard and protection of blood lipids from oxidative damage. The food that is the subject of the health claim, a combination...... of the following frozen vegetables: red spinach (Spinacia oleracea L.), green spinach (Spinacia oleracea L.), red chicory (Cichorium intybus L.), green chicory (Cichorium intybus L.), green leaf chard (Beta vulgaris L. var. cicla), red leaf chard (Beta vulgaris L. var. cicla), red Swiss chard (Beta vulgaris L. var...... conclusions could be drawn for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between consumption of a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf...

  4. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the substantiation of a health claim related to a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden Swiss chard

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden Swiss chard and white Swiss chard and maintenance of normal blood cholesterol concentration. The food that is the subject of the health claim, a combination of red...... spinach (Spinacia oleracea L.), green spinach (Spinacia oleracea L.), red chicory (Cichorium intybus L.), green chicory (Cichorium intybus L.), green leaf chard (Beta vulgaris L. var. cicla), red leaf chard (Beta vulgaris L. var. cicla), red Swiss chard (Beta vulgaris L. var. cicla), golden Swiss chard...... for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between consumption of a combination of red spinach, green spinach, red chicory, green chicory, green leaf chard, red leaf chard, red Swiss chard, golden...

  5. The stem and leaf super green mutant induced by 60Co γ-rays irradiation

    International Nuclear Information System (INIS)

    Wei Yubo; Liang Naiting; Buhaliqiem; Zhang Yinbao

    2003-01-01

    Super green gene mutant was developed from population of M 2 generation after the dry seeds of rice Huazhiwu from Japan with good quality and resistance to cold had been irradiated with 50 Gy 60 Co γ-ray. The leaf, sheath, panicle axis and petiole of mutant was characterized by deeply green, and did not turn yellow after maturing date. The chlorophyll content in straw is 2.2 times higher than that in common straw. The results of raising livestock showed that horse, donkey and sheep had evident selectivity to the green straw

  6. Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

    Science.gov (United States)

    Bracho-Nunez, A.; Knothe, , N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

    2013-09-01

    Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions, including reactive VOC species which are not

  7. Leaf level emissions of volatile organic compounds (VOC from some Amazonian and Mediterranean plants

    Directory of Open Access Journals (Sweden)

    A. Bracho-Nunez

    2013-09-01

    Full Text Available Emission inventories defining regional and global biogenic volatile organic compounds (VOC emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity and physics (secondary organic aerosol formation and effects. The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene < limonene < sabinene < ß-pinene. Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed

  8. The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

    Science.gov (United States)

    Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

    2006-08-01

    The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

  9. Green light drives leaf photosynthesis more efficiently than red light in strong white light: revisiting the enigmatic question of why leaves are green.

    Science.gov (United States)

    Terashima, Ichiro; Fujita, Takashi; Inoue, Takeshi; Chow, Wah Soon; Oguchi, Riichi

    2009-04-01

    The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic capacity profile. In strong white light, therefore, the quantum yield of photosynthesis would be lower in the upper chloroplasts, located near the illuminated surface, than that in the lower chloroplasts. Because green light can penetrate further into the leaf than red or blue light, in strong white light, any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a greater extent than would additional red or blue light. Based on the assessment of effects of the additional monochromatic light on leaf photosynthesis, we developed the differential quantum yield method that quantifies efficiency of any monochromatic light in white light. Application of this method to sunflower leaves clearly showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light. The green leaf should have a considerable volume of chloroplasts to accommodate the inefficient carboxylation enzyme, Rubisco, and deliver appropriate light to all the chloroplasts. By using chlorophylls that absorb green light weakly, modifying mesophyll structure and adjusting the Rubisco/chlorophyll ratio, the leaf appears to satisfy two somewhat conflicting requirements: to increase the absorptance of photosynthetically active radiation, and to drive photosynthesis efficiently in all the chloroplasts. We also discuss some serious problems that are caused by neglecting these intra-leaf profiles when estimating whole leaf electron transport rates and assessing photoinhibition by fluorescence techniques.

  10. The leaf-level emission factor of volatile isoprenoids: caveats, model algorithms, response shapes and scaling

    Directory of Open Access Journals (Sweden)

    Ü. Niinemets

    2010-06-01

    Full Text Available In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission potential under specified environmental conditions, also called as the emission factor, ES. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993, instantaneous variation of the steady-state emission rate is described as the product of ES and light and temperature response functions. When these models are employed in the atmospheric chemistry modeling community, species-specific ES values and parameter values defining the instantaneous response curves are often taken as initially defined. In the current review, we argue that ES as a characteristic used in the models importantly depends on our understanding of which environmental factors affect isoprenoid emissions, and consequently need standardization during experimental ES determinations. In particular, there is now increasing consensus that in addition to variations in light and temperature, alterations in atmospheric and/or within-leaf CO2 concentrations may need to be included in the emission models. Furthermore, we demonstrate that for less volatile isoprenoids, mono- and sesquiterpenes, the emissions are often jointly controlled by the compound synthesis and volatility. Because of these combined biochemical and physico-chemical drivers, specification of ES as a constant value is incapable of describing instantaneous emissions within the sole assumptions of fluctuating light and temperature as used in the standard algorithms. The definition of ES also varies depending on the degree of aggregation of ES values in different parameterization schemes (leaf- vs. canopy- or region-scale, species vs. plant functional type levels and various

  11. Adsorption of malachite green dye from aqueous solution on the bamboo leaf ash

    Science.gov (United States)

    Kuntari, Priwidyanjati, Dessyntha Anggiani

    2017-12-01

    Bamboo leaf ash has been developed as an adsorbent material for removal malachite green from aqueous solution. Adsorption parameters have studied are contact time and initial pH. The effect of contact time and pH were examined in the batch adsorption processes. The physicochemical characters of bamboo leaf ash were investigated by using X-Ray Diffraction (XRD) and FT-IR spectroscopy. Malachite green concentration was determined by UV-Vis spectrophotometer. FT-IR spectrogram of bamboo leaf ash shows that typical fingerprint of adsorbent material with Si-O-Si or Al-O-Al group. The X-ray diffractograms of bamboo leaf ash show that adsorbent material has a highly amorphous nature. The percentage of adsorption was showed raised with increasing contact time. The optimum removal of malachite green when the initial dye concentration, initial pH, weight of adsorbent and contact time was 20 mg/L, 7, 0.25 g and 75 minutes respectively.

  12. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

  13. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Science.gov (United States)

    Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

  14. A facile and green preparation of reduced graphene oxide using Eucalyptus leaf extract

    Science.gov (United States)

    Li, Chengyang; Zhuang, Zechao; Jin, Xiaoying; Chen, Zuliang

    2017-11-01

    In this paper, a green and facile synthesis of reduced graphene oxide (GO) by Eucalyptus leaf extract (EL-RGO) was investigated, which was characterized with ultraviolet-visible spectroscopy (UV), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Thermal gravimetric analysis (TG). Eucalyptus leaf extract also play both reducing and capping stabilizing agents prepared EL-RGO as shown a good stability and electrochemical properties. This approach could provide an alternative method to prepare EL-RGO in large-scale production. Moreover, the good electrochemical property and biocompatibility can be used in various applications. In addition, the merit of this study is that both the oxidized products and the reducing agents are environmental friendly by green reduction.

  15. Application of radiation technology to develop green tea leaf as a natural resource for the cosmetic industry

    International Nuclear Information System (INIS)

    Byun, Myung Woo; Jo, Cheorun; Lee, Ju Woon; Jo, Sung Kee; Kim, Kwan Soo

    2004-01-01

    The irradiation of natural resources such as green tea leaf, persimmon leaf, licorice root and stolon or Lonicera japonica improved the color of the extract, resulting in a higher applicability without any adverse change to the beneficial functions such as the inhibitory effects of oxidation, melanin hyperpigmentation on the skin, and others. To investigate the application of irradiated natural resources for a real cosmetic composition, the physiological activities of irradiated green tea leaf extract powder dissolved in butylene glycol and ethanol were compared to a commercial green tea extract product. Furthermore, a cream lotion was manufactured using the powder and the physiological activities were compared. Results showed that the irradiation of the green tea leaf extract and the freeze-dried powder from the extract had the same physiological activities as the commercial product in a cosmetic composition

  16. [Elimination of volatile compounds of leaf tobacco from air emissions using biofiltration].

    Science.gov (United States)

    Zagustina, N A; Misharina, T A; Vepritskiĭ, A A; Zhukov, V G; Ruzhitskiĭ, A O; Terenina, M B; Krikunova, N I; Kulikova, A K; Popov, V O

    2012-01-01

    The composition of the volatile organic compounds (VOCs) of various leaf tobacco brands and their blends has been studied. The differences in the content of nicotine, solanone, tetramethyl hexadecenol, megastigmatrienones, and other compounds, determining the specific tobacco smell, have been revealed. A microbial consortium, which is able to deodorize simulated tobacco emissions and decompose nicotine, has been formed by long-term adaptation to the VOCs of tobacco leaves in a laboratory reactor, functioning as a trickle-bed biofilter. Such a biofilter eliminates 90% of the basic toxic compound (nicotine) and odor-active compounds; the filtration efficiency does not change for tobacco brands with different VOC concentrations or in the presence of foreign substances. The main strains, isolated from the formed consortium and participating in the nicotine decomposition process, belong to the genera Pseudomonas, Bacillus, and Rhodococcus. An examination of the biofilter trickling fluid has shown full decomposition of nicotine and odor-active VOCs. The compounds, revealed in the trickling fluid, did not have any odor and were nontoxic. The obtained results make it possible to conduct scaling of the biofiltration process to eliminate odor from air emissions in the tobacco industry.

  17. Leaf enclosure measurement for determining marijuana volatile organic compound emission factors

    Science.gov (United States)

    Wang, C. T.; Vizuete, W.; Wiedinmyer, C.; Ashworth, K.; Harley, P. C.; Ortega, J. V.

    2017-12-01

    In 2014, Colorado became the first US state to legalize the industrial-scale cultivation of marijuana plants. There are now more than 700 marijuana cultivation facilities (MCFs) in operation in the greater Denver area. High concentrations of biogenic volatile organic compounds (VOCs), predominantly monoterpenes (C10H16) such as alpha-pinene, myrcene, and limonene have been observed in the grow rooms of MCFs, suggesting MCFs have the potential to release a significant amount of reactive VOCs into the atmosphere. Further, many MCFs are located in the urban core, where other urban emission sources are concentrated, resulting in interactions which can lead to the formation of ozone, impacting air quality. The little research done on marijuana has focused on indoor air quality and occupational exposure, or identification of the compounds associated with the characteristic smells of marijuana plants. We know of no previous studies that have identified or quantified the monoterpene emission rates from marijuana. Here, we collected air samples from leaf enclosures from different marijuana clones at different growth stages onto sorbent cartridges. These samples were analyzed using GC-MS/-FID to identify and quantify the VOCs emitted by growing marijuana plants. These results were then used to estimate basal emission rates at standard conditions (T=30 C, PPFD = 1000 umol/m2/s) using standard algorithms. We discuss the potential impact on air quality from these VOCs emitted into the atmosphere using air quality models.

  18. Vegetation growth parameters and leaf temperature: Experimental results from a six plots green roofs' system

    International Nuclear Information System (INIS)

    Ferrante, Patrizia; La Gennusa, Maria; Peri, Giorgia; Rizzo, Gianfranco; Scaccianoce, Gianluca

    2016-01-01

    The paper provides a contribution for populating database of three physical parameters needed to model energy performance of buildings with green roofs: “coverage ratio” (σ_f), leaf area index (LAI) and leaf temperature (T_f). On purpose, six plant species were investigated experimentally: Phyla nordiflora, Aptenia lancifolia, Mesembryanthenum barbatus, Gazania nivea, Gazania uniflora, and Sedum. Proper ranges of the cited parameters have been found for each species. The here indicated ranges of σ_f values refer to different growth levels of the species in the same lapse of time, that is four months. Single measured LAI values are also reported for the same plants. As for the T_f (upper and lower layer), ranges of revealed temperatures refer to those detected from 10:30 a.m. to 16:30 p.m. of a selected day. Additionally, the dependence of T_f on climatic parameters was investigated. A linear equation resulted the best fitting curve for all experimental T_f data and the corresponding solar radiation data (with autocorrelation coefficients between 0.80 and 0.98). Furthermore, the effect potentially produced on building energy consumption by these species was analyzed using a simulation tool. Estimated cooling energy savings range approximately between 8% and 20% depending on adopted plants. - Highlights: • Green roof modeling requires the knowledge of various physical parameters. • Coverage ratio, leaf area index and leaves temperatures were measured for six species. • A tentative correlation between leaf temperature and climatic parameters was shown. • A correlation between LAI and coverage ratio was checked and discussed. • Potential effects of studied species on building energy consumption were investigated.

  19. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yan-yu [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Yang, Hui, E-mail: 549456369@qq.com [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Wang, Tao [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Wang, Chuang [Department of Highway & Bridge, Shaanxi Railway Institute, Weinan 714000 (China)

    2016-11-25

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag{sup +} (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO{sub 3}) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO{sub 3} concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV–vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10–16 nm. FTIR analysis revealed that biological macromolecules with groups of −NH{sub 2}, −OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications. - Highlights: • Monodisperse silver nanoparticles were first prepared by a green synthetical way through Ginkgo Biloba leaf extract. • The synthesized AgNPs is of high crystallinity, stable and good dispersion with smaller sizes between 10–16 nm. • The achieved AgNPs exhibits good antibacterial activities. • The biosynthesis method is advantageous for its cost effectiveness, availability, portability, nontoxic and environmentally benign.

  20. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    International Nuclear Information System (INIS)

    Ren, Yan-yu; Yang, Hui; Wang, Tao; Wang, Chuang

    2016-01-01

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag + (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO 3 ) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO 3 concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV–vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10–16 nm. FTIR analysis revealed that biological macromolecules with groups of −NH 2 , −OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications. - Highlights: • Monodisperse silver nanoparticles were first prepared by a green synthetical way through Ginkgo Biloba leaf extract. • The synthesized AgNPs is of high crystallinity, stable and good dispersion with smaller sizes between 10–16 nm. • The achieved AgNPs exhibits good antibacterial activities. • The biosynthesis method is advantageous for its cost effectiveness, availability, portability, nontoxic and environmentally benign.

  1. Green leaf phenology at Landsat resolution: scaling from the plot to satellite

    Science.gov (United States)

    Fisher, J. I.; Mustard, J. F.; Vadeboncour, M.

    2005-12-01

    Despite the large number of in situ, plot-level phenological measurements and satellite-derived phenological studies, there has been little success to date in merging these records temporally or spatially. In particular, while most phenological patterns and trends derived from satellites appear realistic and coherent, they may not reflect spatial and temporal patterns at the plot level. An obvious explanation is the drastic scale difference from plot-level to most satellite observations. In this research, we bridge this scale gap through higher resolution satellite records (Landsat) and quantify the accuracy of satellite-derived metrics with direct field measurements. We compiled fifty-seven Landsat scenes from southern New England (P12 R51) from 1984 to 2002. Green vegetation areal abundance for each scene was derived from spectral mixture analysis and a single set of endmembers. The leaf area signal was fit with a logistic-growth simulating sigmoid curve to derive phenological markers (half-maximum leaf-onset and offset). Spring leaf-onset dates in homogenous stands of deciduous forests displayed significant and persistent local variability. The local variability was validated with multiple springtime ground observations (r2 = 0.91). The highest degree of verified small-scale variation occurred where contiguous forests displayed leaf-onset gradients of 10-14 days over short distances (example, our results indicate that deciduous forests in the Providence, RI metropolitan area leaf out 5-7 days earlier than comparable rural areas. In preliminary work, we validated the Landsat-derived metrics with similar analyses of MODIS and AVHRR, and demonstrate that aggregating diverse local phenologies into coarse grids may convolute interpretations. Despite these complications, the platform-independent curve-fit methodology may be extended across platforms and field data. The methodologically consistent approach, in tandem with Landsat data, allows us to effectively scale

  2. Green synthesis and characterization of silver nanoparticles using Lantana camara leaf extract

    International Nuclear Information System (INIS)

    Ajitha, B.; Ashok Kumar Reddy, Y.; Sreedhara Reddy, P.

    2015-01-01

    In this work, we have investigated on Lantana camara mediated silver nanoparticles (AgNPs) with different leaf extract (LE) quantity for the evaluation of efficient bactericidal activity. The AgNPs were prepared by simple, capable, eco-friendly and biosynthesis method using L. camara LE. This method allowed the synthesis of crystalline nanoparticles, which was confirmed by X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns. The X-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of metallic silver and elucidates the surface state composition of AgNPs. UV–vis spectra of AgNPs and visual perception of brownish yellow color from colorless reaction mixture confirmed the AgNP formation. Involvement of functional groups of L. camara leaf extract in the reduction and capping process of nanoparticles was well displayed in Fourier transform infrared spectroscopy (FTIR). Decrement of particle size with an increment of leaf extract volume was evident in AFM, TEM images and also through a blue shift in the UV–vis spectra. The rate of formation and size of AgNPs were dependent on LE quantity. Meanwhile, these AgNPs exhibited effective antibacterial activity with the decrement of particle size against all tested bacterial cultures. - Highlights: • Monodispersed AgNPs are synthesized using L. camara leaf extract. • The higher the L. camara content, the smaller the particle size. • Green synthesized AgNPs are found to be photoluminescent. • Size dependence of antibacterial activity is reported. • The nanoparticle stability is improved by leaf extract quantity

  3. Green synthesis and characterization of silver nanoparticles using Lantana camara leaf extract

    Energy Technology Data Exchange (ETDEWEB)

    Ajitha, B., E-mail: ajithabondu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Ashok Kumar Reddy, Y. [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Sreedhara Reddy, P. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    2015-04-01

    In this work, we have investigated on Lantana camara mediated silver nanoparticles (AgNPs) with different leaf extract (LE) quantity for the evaluation of efficient bactericidal activity. The AgNPs were prepared by simple, capable, eco-friendly and biosynthesis method using L. camara LE. This method allowed the synthesis of crystalline nanoparticles, which was confirmed by X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns. The X-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of metallic silver and elucidates the surface state composition of AgNPs. UV–vis spectra of AgNPs and visual perception of brownish yellow color from colorless reaction mixture confirmed the AgNP formation. Involvement of functional groups of L. camara leaf extract in the reduction and capping process of nanoparticles was well displayed in Fourier transform infrared spectroscopy (FTIR). Decrement of particle size with an increment of leaf extract volume was evident in AFM, TEM images and also through a blue shift in the UV–vis spectra. The rate of formation and size of AgNPs were dependent on LE quantity. Meanwhile, these AgNPs exhibited effective antibacterial activity with the decrement of particle size against all tested bacterial cultures. - Highlights: • Monodispersed AgNPs are synthesized using L. camara leaf extract. • The higher the L. camara content, the smaller the particle size. • Green synthesized AgNPs are found to be photoluminescent. • Size dependence of antibacterial activity is reported. • The nanoparticle stability is improved by leaf extract quantity.

  4. Antidepressant-like effects of young green barley leaf (Hordeum vulgare L.) in the mouse forced swimming test.

    Science.gov (United States)

    Yamaura, Katsunori; Nakayama, Noriyuki; Shimada, Maki; Bi, Yuanyuan; Fukata, Hideki; Ueno, Koichi

    2012-01-01

    Young green barley leaf is one of the richest sources of antioxidants and has been widely consumed for health management in Japan. In this study, we examined whether oral administration of young green barley leaf has an antidepressant effect on the forced swimming test in mice. Mice were individually forced to swim in an open cylindrical container, one hour after oral administration of young green barley leaf (400 or 1000 mg / kg) or imipramine (100 mg / kg). Expression of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor, and glucocorticoid receptor in the brain was analyzed using real-time quantitative polymerase chain reaction (PCR). There was a significant antidepressant-like effect in the forced swimming test; both 400 and 1000 mg / kg young green barley leaves, as well as the positive control imipramine (100 mg / kg), reduced the immobility duration compared to the vehicle group. The expression of mRNA for NGF detected in the hippocampus immediately after the last swimming test was higher than that in the non-swimming group (Nil). Oral administration of imipramine suppressed this increase to the level of the Nil group. Young green barley leaf (400 and 1000 mg / kg) also showed a moderate decrease in the expression of mRNA for NGF, in a dose-dependent manner. Oral administration of young green barley leaf is able to produce an antidepressant-like effect in the forced swimming test. Consequently it is possible that the antidepressant-like effects of the young green barley leaf are, at least in part, mediated by an inhibition of the increase in the hippocampus levels of NGF.

  5. Antimicrobial potential of green synthesized CeO2 nanoparticles from Olea europaea leaf extract.

    Science.gov (United States)

    Maqbool, Qaisar; Nazar, Mudassar; Naz, Sania; Hussain, Talib; Jabeen, Nyla; Kausar, Rizwan; Anwaar, Sadaf; Abbas, Fazal; Jan, Tariq

    This article reports the green fabrication of cerium oxide nanoparticles (CeO 2 NPs) using Olea europaea leaf extract and their applications as effective antimicrobial agents. O. europaea leaf extract functions as a chelating agent for reduction of cerium nitrate. The resulting CeO 2 NPs exhibit pure single-face cubic structure, which is examined by X-ray diffraction, with a uniform spherical shape and a mean size 24 nm observed through scanning electron microscopy and transmission electron microscopy. Ultraviolet-visible spectroscopy confirms the characteristic absorption peak of CeO 2 NPs at 315 nm. Fourier transform infrared spectroscopy reflects stretching frequencies at 459 cm -1 , showing utilization of natural components for the production of NPs. Thermal gravimetric analysis predicts the successful capping of CeO 2 NPs by bioactive molecules present in the plant extract. The antimicrobial studies show significant zone of inhibition against bacterial and fungal strains. The higher activities shown by the green synthesized NPs than the plant extract lead to the conclusion that they can be effectively used in biomedical application. Furthermore, reduction of cerium salt by plant extract will reduce environmental impact over chemical synthesis.

  6. Green Synthesis of Silver Nanoparticles by using Eucalyptus Globulus Leaf Extract

    Science.gov (United States)

    Balamurugan, Madheswaran; Saravanan, Shanmugam

    2017-12-01

    A single step eco-friendly, energy efficient and economically scalable green method was employed to synthesize silver nanoparticles. In this work, the synthesis of silver nanoparticles using Eucalyptus globulus leaf extract as reducing and capping agent along with water as solvent at normal room temperature is described. Silver nanoparticles were prepared from aqueous silver nitrate solution by adding the leaf extract. The prepared nanoparticles were characterized by using UV-visible Spectrophotometer, X-ray diffractometer, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscope (FTIS). X-ray diffraction studies brought to light the crystalline nature and the face centered cubic structure of the silver nanoparticles. Using HR-TEM. the nano sizes and morphology of the particles were studied. The mean sizes of the prepared silver nanoparticles ranged from 30 to 36 nm. The density of the particles was tuned by varying the molar ratio of silver nitrate. FTIS studies showed the functional group of organic molecules which were located on the surface of the silver nanoparticles. Originating from the leaf extracts, these organic molecules reduced and capped the particles.

  7. Green synthesis, characterization and antibacterial efficacy of palladium nanoparticles synthesized using Filicium decipiens leaf extract

    Science.gov (United States)

    Sharmila, G.; Farzana Fathima, M.; Haries, S.; Geetha, S.; Manoj Kumar, N.; Muthukumaran, C.

    2017-06-01

    Synthesis of metal nanoparticles through green chemistry route is an emerging eco-friendly approach in the present days. An eco-friendly, biogenic synthesis of palladium nanoparticles (PdNPs) using Filicium decipiens leaf extract was reported in the present study. The synthesized PdNPs were characterized by UV-visible spectroscopy, Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The PdNPs formation was confirmed by UV-visible spectrophotometer and spherical shaped PdNPs with size range of 2-22 nm was observed in TEM analysis. Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of palladium in the synthesized nanoparticles. The crystalline nature of PdNPs was confirmed by XRD pattern and compared with the standard. The phytochemicals and proteins were identified by their functional groups in FT-IR spectrum and revealed the amide, amine groups present in F. decipiens may have involved in the bio-reduction reaction for PdNPs synthesis. Prepared PdNPs showed potential antibacterial activity against both Gram-positive and Gram-negative bacteria. F. decipiens leaf extract based PdNPs showed high bactericidal activity against Escherichia coli, Pseudomonas aeruginosa as compared to Staphylococcus aureus and Bacillus subtilis Results showed that phytochemicals rich F. decipiens leaf extract may be utilized as an effective non-toxic reducing agent for PdNPs synthesis and prepared PdNPs may useful in biomedical applications.

  8. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    Science.gov (United States)

    Ren, Yan-yu; Yang, Hui; Wang, Tao; Wang, Chuang

    2016-11-01

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag+ (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO3) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO3 concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV-vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10-16 nm. FTIR analysis revealed that biological macromolecules with groups of sbnd NH2, sbnd OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications.

  9. Antimicrobial potential of green synthesized CeO2 nanoparticles from Olea europaea leaf extract

    Directory of Open Access Journals (Sweden)

    Maqbool Q

    2016-10-01

    Full Text Available Qaisar Maqbool,1 Mudassar Nazar,1 Sania Naz,2 Talib Hussain,3 Nyla Jabeen,4 Rizwan Kausar,5 Sadaf Anwaar,4 Fazal Abbas,6,7 Tariq Jan6 1Department of Biotechnology, Virtual University of Pakistan, Lahore, Pakistan; 2Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan; 3National Institute of Vacuum Science and Technology (NINVAST, Islamabad, Pakistan; 4Department of Biotechnology and Bioinformatics Lab., International Islamic University, Islamabad, Pakistan; 5Department of Chemistry, University of Sargodha, Sargodha, Pakistan; 6Department of Physics, International Islamic University, Islamabad, Pakistan; 7Interdisciplinary Research Organization, University of Chakwal (UOC, Chakwal, Pakistan Abstract: This article reports the green fabrication of cerium oxide nanoparticles (CeO2 NPs using Olea europaea leaf extract and their applications as effective antimicrobial agents. O. europaea leaf extract functions as a chelating agent for reduction of cerium nitrate. The resulting CeO2 NPs exhibit pure single-face cubic structure, which is examined by X-ray diffraction, with a uniform spherical shape and a mean size 24 nm observed through scanning electron microscopy and transmission electron microscopy. Ultraviolet-visible spectroscopy confirms the characteristic absorption peak of CeO2 NPs at 315 nm. Fourier transform infrared spectroscopy reflects stretching frequencies at 459 cm-1, showing utilization of natural components for the production of NPs. Thermal gravimetric analysis predicts the successful capping of CeO2 NPs by bioactive molecules present in the plant extract. The antimicrobial studies show significant zone of inhibition against bacterial and fungal strains. The higher activities shown by the green synthesized NPs than the plant extract lead to the conclusion that they can be effectively used in biomedical application. Furthermore, reduction of cerium salt by plant extract will reduce environmental impact over

  10. Effect of supplemental ultraviolet radiation on the concentration of phytonutrients in green and red leaf lettuce (Lactuca sativa) cultivars

    Science.gov (United States)

    Britz, Steven; Caldwell, Charles; Mirecki, Roman; Slusser, James; Gao, Wei

    2005-08-01

    Eight cultivars each of red and green leaf lettuce were raised in a greenhouse with supplemental UV radiation, either UV-A (wavelengths greater than ca. 315 nm) or UV-A+UV-B (wavelengths greater than ca. 290 nm; 6.4 kJ m-2 daily biologically effective UV-B), or no supplemental UV (controls). Several phytonutrients were analyzed in leaf flours to identify lines with large differences in composition and response to UV-B. Red leaf lettuce had higher levels of phenolic acid esters, flavonols and anthocyanins than green lines. Both green and red lines exposed to UV-B for 9 days showed 2-3-fold increases in flavonoids compared to controls, but only 45% increases in phenolic acid esters, suggesting these compounds may be regulated by different mechanisms. There were large differences between cultivars in levels of phenolic compounds under control conditions and also large differences in UV-B effects. Among red varieties, cv. Galactic was notable for high levels of phenolics and a large response to UV-B. Among green varieties, cvs. Black-Seeded Simpson and Simpson Elite had large increases in phenolics with UV-B exposure. Photosynthetic pigments were also analyzed. Green leaf lettuce had high levels of pheophytin, a chlorophyll degradation product. Total chlorophylls (including pheophytin) were much lower in green compared to red varieties. Lutein, a carotenoid, was similar for green and red lines. Total chlorophylls and lutein increased 2-fold under supplemental UV-B in green lines but decreased slightly under UV-B in red lines. Lettuce appears to be a valuable crop to use to study phytochemical-environment interactions.

  11. Green leaf allowance and dairy ewe performance grazing on tropical pasture.

    Science.gov (United States)

    De Souza, J; Batistel, F; Ticiani, E; Sandri, E C; Pedreira, C G S; Oliveira, D E

    2014-06-01

    The objective of this study was to explain the influence of green leaf allowance levels on the performance of dairy ewes grazing a tropical grass. Seventy-two lactating ewes grazed Aruana guineagrass (Panicum maximum Jacq. cv. Aruana) for 80 d. The treatments were 4 daily levels of green leaf allowance (GLA) on a DM basis corresponding to 4, 7, 10, and 13 kg DM/100 kg BW, which were named low, medium-low, medium-high, and high level, respectively. The experimental design was completely randomized with 3 replications. During the experimental period, 4 grazing cycles were evaluated in a rotational stocking grazing method (4 d of grazing and 16 d of rest). There was a linear effect of GLA on forage mass, and increasing GLA resulted in increased total leaf mass, reaching an asymptotic plateau around the medium-high GLA level. The stem mass increased with increased GLA, and a pronounced increase was observed between medium-high and high GLAs. Increasing GLA increased both forage disappearance rate and postgrazing forage mass. Leaf proportion increased with GLA, peaking at the medium-high level, and the opposite occurred for stem proportions, which reduced until medium-high GLA level, followed by an increase on high GLA. Forage CP decreased linearly with GLA, and increasing GLA from low to high reduced CP content by 31%. On the other hand, NDF increased 14% and ADF increased 26%, both linearly in response to greater GLA levels. Total digestible nutrients decreased linearly by 8% when GLA increased from low to high level. Milk yield increased, peaking at medium-high GLA (1.75 kg ewe(-1) d(-1)) and decreased at high GLA level (1.40 kg ewe(-1) d(-1)). Milk composition was not affected by the GLA levels. There was a reduction in stocking rate from 72 to 43 ewes/ha when GLA increased from low to high level. Productivity (milk yield kg ha(-1) d(-1)) increased as GLA increased, peaking at medium-low level (115 kg ha(-1) d(-1)). Although this tropical grass showed the same

  12. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Yamamoto

    2014-01-01

    Full Text Available Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS, has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera, Tokushima (Ulva prolifera, and Ehime prefecture (Ulva linza. Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera and Tokushima prefecture (Ulva prolifera. Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum. Multivariant statistical analysis (PCA enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  13. Determination of volatile compounds in four commercial samples of Japanese green algae using solid phase microextraction gas chromatography mass spectrometry.

    Science.gov (United States)

    Yamamoto, Masayoshi; Baldermann, Susanne; Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  14. Large Drought-induced Variations in Oak Leaf Volatile Organic Compound Emissions during PINOT NOIR 2012

    Data.gov (United States)

    U.S. Environmental Protection Agency — Leaf level oak isoprene emissions and co2/H2O exchange in the Ozarks, USA BAGeron.csv is the speciated biomass displayed in Figure 1. Biomass Dry Weights.xlsx is...

  15. Green synthesis of silver nanoparticles using Azadirachta indica leaf extract and its antimicrobial study

    Science.gov (United States)

    Roy, Pragyan; Das, Bhagyalaxmi; Mohanty, Abhipsa; Mohapatra, Sujata

    2017-11-01

    In this study, green synthesis of silver nanoparticles was done using leaf extracts of Azadirachta indica. The flavonoids and terpenoids present in the extract act as both reducing and capping agent. Microbes ( Escherichia coli and Gram-positive bacteria) were isolated from borewell water using selective media. The silver nanoparticles showed antimicrobial activities against Gram-positive bacteria and E. coli. However the silver nanoparticles were more effective against E. coli as compared to Gram-positive bacteria. Various techniques were used to characterize synthesized silver nanoparticles such as DLS and UV-visible spectrophotometer. The absorbance peak was in the range of 420-450 nm, that varied depending upon the variation in the concentration of neem extract. This is a very rapid and cost-effective method for generation of silver nanoparticle at room temperature, however, its exact dose in water purification has to be determined.

  16. Climatic factors directly impact the volatile organic compound fingerprint in green Arabica coffee bean as well as coffee beverage quality.

    Science.gov (United States)

    Bertrand, B; Boulanger, R; Dussert, S; Ribeyre, F; Berthiot, L; Descroix, F; Joët, T

    2012-12-15

    Coffee grown at high elevations fetches a better price than that grown in lowland regions. This study was aimed at determining whether climatic conditions during bean development affected sensory perception of the coffee beverage and combinations of volatile compounds in green coffee. Green coffee samples from 16 plots representative of the broad range of climatic variations in Réunion Island were compared by sensory analysis. Volatiles were extracted by solid phase micro-extraction and the volatile compounds were analysed by GC-MS. The results revealed that, among the climatic factors, the mean air temperature during seed development greatly influenced the sensory profile. Positive quality attributes such as acidity, fruity character and flavour quality were correlated and typical of coffees produced at cool climates. Two volatile compounds (ethanal and acetone) were identified as indicators of these cool temperatures. Among detected volatiles, most of the alcohols, aldehydes, hydrocarbons and ketones appeared to be positively linked to elevated temperatures and high solar radiation, while the sensory profiles displayed major defects (i.e. green, earthy flavour). Two alcohols (butan-1,3-diol and butan-2,3-diol) were closely correlated with a reduction in aromatic quality, acidity and an increase in earthy and green flavours. We assumed that high temperatures induce accumulation of these compounds in green coffee, and would be detected as off-flavours, even after roasting. Climate change, which generally involves a substantial increase in average temperatures in mountainous tropical regions, could be expected to have a negative impact on coffee quality. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Leaf green-up in a semi-arid African savanna - separating tree and grass responses to environmental cues

    CSIR Research Space (South Africa)

    Archibald, S

    2007-01-01

    Full Text Available -arid African savanna - 583 Journal of Vegetation Science 18: 583-594, 2007 © IAVS; Opulus Press Uppsala. Leaf green-up in a semi-arid African savanna – separating tree and grass responses to environmental cues Archibald, S.1* & Scholes, R.J.1,2 1Natural... to identify tree and grass green-up dates in a semi-arid savanna system, and are there predictable environmental cues for green-up for each life form? Location: Acacia nigrescens/Combretum apiculatum savanna, Kruger National Park, South Africa (25° S, 31...

  18. Green fabricated CuO nanobullets via Olea europaea leaf extract shows auspicious antimicrobial potential.

    Science.gov (United States)

    Maqbool, Qaisar; Iftikhar, Sidra; Nazar, Mudassar; Abbas, Fazal; Saleem, Asif; Hussain, Talib; Kausar, Rizwan; Anwaar, Sadaf; Jabeen, Nyla

    2017-06-01

    In present investigation, copper oxide (CuO) nanostructures have been prepared via green chemistry. Olea europaea leaf extract act as strong chelating agent for tailoring physical as well as bio-medical characteristics of CuO at the nano-size. Physical characterisation such as scanning electron microscope analysis depicts the formation of homogenised spherical shape nanoparticles (NPs) with average size of 42 nm. X-ray diffraction and Fourier transform infrared spectroscopy further confirmed the crystalline pure phase and monoclinic structure. High performance liquid chromatography (HPLC) testing is performed to evaluate the relative concentration of bioactive molecules in the O. europaea leaf extract. From HPLC results capping action of organic molecules around CuO-NPs is hypothesised. The antimicrobial potency of biosynthesised CuO-NPs have been evaluated using colony forming unit (CFU) counting assay and disc diffusion method which shows a significant zone of inhibition against bacterial and fungal strains may be highly potential for future antimicrobial pharmaceutics. Furthermore, reduction of various precursors by plant extract will reduce environmental impact over chemical synthesis.

  19. Simple luminosity normalization of greenness, yellowness and redness/greenness for comparison of leaf spectral profiles in multi-temporally acquired remote sensing images.

    Science.gov (United States)

    Doi, Ryoichi

    2012-09-01

    Observation of leaf colour (spectral profiles) through remote sensing is an effective method of identifying the spatial distribution patterns of abnormalities in leaf colour, which enables appropriate plant management measures to be taken. However, because the brightness of remote sensing images varies with acquisition time, in the observation of leaf spectral profiles in multi-temporally acquired remote sensing images, changes in brightness must be taken into account. This study identified a simple luminosity normalization technique that enables leaf colours to be compared in remote sensing images over time. The intensity values of green and yellow (green+red) exhibited strong linear relationships with luminosity (R2 greater than 0.926) when various invariant rooftops in Bangkok or Tokyo were spectralprofiled using remote sensing images acquired at different time points. The values of the coefficient and constant or the coefficient of the formulae describing the intensity of green or yellow were comparable among the single Bangkok site and the two Tokyo sites, indicating the technique's general applicability. For single rooftops, the values of the coefficient of variation for green, yellow, and red/green were 16% or less (n=6-11), indicating an accuracy not less than those of well-established remote sensing measures such as the normalized difference vegetation index. After obtaining the above linear relationships, raw intensity values were normalized and a temporal comparison of the spectral profiles of the canopies of evergreen and deciduous tree species in Tokyo was made to highlight the changes in the canopies' spectral profiles. Future aspects of this technique are discussed herein.

  20. GCMS investigation of volatile compounds in green coffee affected by potato taste defect and the Antestia bug.

    Science.gov (United States)

    Jackels, Susan C; Marshall, Eric E; Omaiye, Angelica G; Gianan, Robert L; Lee, Fabrice T; Jackels, Charles F

    2014-10-22

    Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.

  1. Characterization of the volatile components in green tea by IRAE-HS-SPME/GC-MS combined with multivariate analysis.

    Science.gov (United States)

    Yang, Yan-Qin; Yin, Hong-Xu; Yuan, Hai-Bo; Jiang, Yong-Wen; Dong, Chun-Wang; Deng, Yu-Liang

    2018-01-01

    In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP) values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA) allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties.

  2. Characterization of the volatile components in green tea by IRAE-HS-SPME/GC-MS combined with multivariate analysis.

    Directory of Open Access Journals (Sweden)

    Yan-Qin Yang

    Full Text Available In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME followed by gas chromatography-mass spectrometry (GC-MS was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA and hierarchical clustering analysis (HCA. Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties.

  3. Volatile constituents of the peel and leaf oils of Citrus limon L. Burm. f. from Benin

    NARCIS (Netherlands)

    Ayedoun, M.A.; Sossou, P.V.; Mardarowicz, M.; Leclercq, P.A.

    1996-01-01

    The peel and leaf oils ofCitrus limon L. from Benin were analyzed by capillary GC on two columns of different polarity, and by GCIMS. In these oils 42 and 27 components were identified, representing over 99.7% ofthe oils. The main constituents of the lemon peel oil were limonene (70.4%), y-terpinene

  4. Comparison of volatile components of flower, leaf, peel and juice of ...

    African Journals Online (AJOL)

    Flower components were extracted by using ultrasound (US) water bath apparatus and then eluted by n-pentane : diethylether (1:2) solvent. ... 37 flower components, 53 leaf components, 54 peel components and 47 juice components including: aldehydes, alcohols, esters, ketones, monoterpenes, sesquiterpenes and other ...

  5. PROTEOMIC PROFILE REVEALS THE DIVERSITY AND COMPLEXITY OF LEAF PROTEINS IN SPINACH (BETA VULGARIS VAR. ALL GREEN

    Directory of Open Access Journals (Sweden)

    Sudip Ghosh

    2016-06-01

    Full Text Available Leaf is a source organ that serves dual function in photosynthesis and transpiration. As a primary interface between plant and ecosystem, it performs a range of biological processes from carbon assimilation and metabolite partitioning to plant productivity. Basic features of the leaf functionality are conserved in angiosperms exhibiting common and unique characteristics. Spinach has been the model crop for studying leaf function, primarily photosynthesis. It is a reservoir of several hundreds of primary and secondary biomolecules. To better understand the molecular basis for photochemical reaction and metabolic partitioning, we developed leaf proteome of Indian spinach (Beta vulgaris var. all green. LC-ESI-MS/MS analysis identified 639 proteins exhibiting discrete molecular features and functions, including photosynthesis, transpiration, gaseous exchange, transport, redox status, cell defense, and floral induction besides the presence of proteins with unknown function. This represents the first comprehensive foliage proteome of green leafy vegetable. Together, this work provides important insights into the molecular networks underlying spinach leaf biological processes.

  6. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  7. Biosorption of Basic Green 4 from aqueous solution by Ananas comosus (pineapple) leaf powder.

    Science.gov (United States)

    Chowdhury, Shamik; Chakraborty, Sagnik; Saha, Papita

    2011-06-01

    Biosorption characteristics of Ananas comosus (pineapple) leaf powder was investigated for decolorization of Basic Green 4 (BG 4), a cationic dye from its aqueous solutions employing a batch experimental set-up. Parameters that influence the sorption process such as pH, biosorbent dosage, contact time, initial dye concentration and temperature were systematically studied. The optimum conditions for removal of BG 4 were found to be pH 9.0, contact time=150 min, biosorbent dosage=5.0 g L(-1), initial dye concentration=50 mg L(-1). The temperature had a strong influence on the biosorption process. Further, the biosorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett, Teller (BET) surface area and pore size analysis. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The biosorption process followed the Langmuir isotherm model with high coefficients of correlation (R(2)>0.99) at different temperatures. The pseudo second order kinetic model fitted well in correlation to the experimental results. Activation energy of the biosorption process (E(a)) was found to be 45.79 kJ mol(-1) by using the Arrhenius equation, indicating chemisorption nature of BG 4 sorption onto pineapple leaf powder. Thermodynamic parameters suggest that the biosorption process is spontaneous and exothermic in nature. Overall, the present findings suggest that this environmentally friendly, efficient and low-cost biosorbent may be useful for the removal of BG 4 from aqueous media. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. A facile and rapid method for the black pepper leaf mediated green synthesis of silver nanoparticles and the antimicrobial study

    Science.gov (United States)

    Augustine, Robin; Kalarikkal, Nandakumar; Thomas, Sabu

    2014-10-01

    Green synthesis of nanoparticles is widely accepted due to the less toxicity in comparison with chemical methods. But there are certain drawbacks like slow formation of nanoparticles, difficulty to control particle size and shape make them less convenient. Here we report a novel cost-effective and eco-friendly method for the rapid green synthesis of silver nanoparticles using leaf extracts of Piper nigrum. Our results suggest that this method can be used for obtaining silver nanoparticles with controllable size within a few minutes. The fabricated nanoparticles possessed excellent antibacterial property against both Gram-positive and Gram-negative bacteria.

  9. Substrates with green manure compost and leaf application of biofertilizer on seedlings of yellow passion fruit plants

    Directory of Open Access Journals (Sweden)

    Cristiane Muniz Barbosa Barros

    2013-12-01

    Full Text Available Substrates and fertilization are fundamental for seedling production, which well nourished can produce earlier and are more resistant to stresses. Animal manures are often used in non-industrialized substrates with good results, but their costs are increasing. Other residues may be used for plant nutrition, in substrates or in leaf fertilization. The aim of this work was to evaluate substrates prepared with green manure composts and the leaf application of biofertilizer on the formation of yellow passion fruit seedlings. A greenhouse experiment was conducted between December 2009 and February 2010, with a split-plot random block design. Plots received or not leaf application of supermagro biofertilizer. Subplots consisted of different substrates: soil; soil + cattle manure; soil + cattle manure composted with black oats straw; soil + cattle manure composted with ryegrass straw; soil + cattle manure composted with turnip straw; and soil + cattle manure composted with vetch straw. There were three dates of leaf fertilization: 10, 25 and 40 days after emergence (DAE. At 50 DAE plants were collected for evaluation of growth and accumulation of biomass and nutrients: N, P, K, Ca, Mg, Cu, Mn and Zn. Data were submitted to analysis of variance and means compared by Tukey test. The substrate soil + cattle manure promoted higher stem diameter, plant height, leaf area, root length and volume and nutrient accumulation. Among substrates with green manure composts, those prepared with black oats and turnip straw outranked the others. The use of leaf biofertilizer showed diverse results on seedling formation, being beneficial when combined to substrates with black oats composted straw, and prejudicial when combined to soil + cattle manure and soil + turnip composted straw substrates. The accumulation of nutrients by the seedlings occurred in the following order: K>Ca>N>Mg>P>Zn>Cu=Mn.

  10. Arctic Vegetation under Climate Change – Biogenic Volatile Organic Compound Emissions and Leaf Anatomy

    DEFF Research Database (Denmark)

    Schollert, Michelle

    common arctic plant species, illustrating the great importance of vegetation composition for determining ecosystem BVOC emissions. Additionally, this thesis assesses the BVOC emission responses in common arctic plant species to effects of climate change: warming, shading and snow addition. Against...... treatment effects on BVOC emissions. Furthermore, the anatomy of arctic plants seems to respond differently to warming than species at lower latitudes. The results in this thesis demonstrate the complexity of the effects of climate change on BVOC emissions and leaf anatomy of arctic plant species...... emissions from the arctic region are assumed to be low, but data from the region is lacking. BVOC emissions are furthermore expected to change drastically due to the rapidly proceeding climate change in the Arctic, which can provide a feedback to climate warming of unknown direction and magnitude. BVOC...

  11. Air quality and health effects of biogenic volatile organic compounds emissions from urban green spaces and the mitigation strategies

    International Nuclear Information System (INIS)

    Ren, Yuan; Qu, Zelong; Du, Yuanyuan; Xu, Ronghua; Ma, Danping; Yang, Guofu; Shi, Yan; Fan, Xing; Tani, Akira; Guo, Peipei; Ge, Ying; Chang, Jie

    2017-01-01

    Biogenic volatile organic compounds (BVOCs) emissions lead to fine particulate matter (PM 2.5 ) and ground-level ozone pollution, and are harmful to human health, especially in urban areas. However, most BVOCs estimations ignored the emissions from urban green spaces, causing inaccuracies in the understanding of regional BVOCs emissions and their environmental and health effects. In this study, we used the latest local vegetation datasets from our field survey and applied an estimation model to analyze the spatial-temporal patterns, air quality impacts, health damage and mitigating strategies of BVOCs emissions in the Greater Beijing Area. Results showed that: (1) the urban core was the hotspot of regional BVOCs emissions for the highest region-based emission intensity (3.0 g C m −2 yr −1 ) among the 11 sub-regions; (2) urban green spaces played much more important roles (account for 62% of total health damage) than rural forests in threating human health; (3) BVOCs emissions from green spaces will more than triple by 2050 due to urban area expansion, tree growth and environmental changes; and (4) adopting proactive management (e.g. adjusting tree species composition) can reduce 61% of the BVOCs emissions and 50% of the health damage related to BVOCs emissions by 2050. - Highlights: • Urban core is the hotspot of biogenic volatile organic compounds (BVOCs) emissions in the Greater Beijing Area. • Neglecting BVOCs emissions from urban green spaces leads to a 62% underestimation of the related health damage. • BVOCs contribute significantly to ozone pollution while make limited contribution to PM 2.5 pollution. • BVOCs emissions from urban green spaces will triple by 2050, and 61% of these emissions can be reduced through management. - Although BVOCs emissions from urban green spaces make limited contribution to regional emissions, their health impacts could be significant in urban areas.

  12. Leaf, branch, stand and landscape scale measurements of volatile organic compound fluxes from U. S. woodlands

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, A.; Greenberg, J.; Harley, P.; Helmig, D.; Klinger, L.; Vierling, L.; Zimmerman, P. [National Center for Atmospheric Research, Boulder, CO (United States). Atmospheric Chemistry Div.; Geron, C. [Environmental Protection Agency, Research Triangle Park, NC (United States)

    1996-01-01

    Natural volatile organic compound (VOC) fluxes were measured in three U.S. woodlands. Fluxes from individual leaves and branches were estimated with enclosure techniques and used to initialize and evaluate VOC emission model estimates. Ambient measurements were used to estimate above canopy fluxes for entire stands. A total of 78 VOCs were identified, with hexenol derivatives being the most commonly observed oxygenated compounds. There was also evidence of high rates of isoprene emission and high rates of monoterpenes in some genera of trees. Model predictions of diurnal variations were within + or - 35 per cent of observed flux variations. Fluxes predicted by a recent version of a biogenic emission model were within 10 per cent to 50 per cent of observed fluxes, leading to the conclusion that existing databases can provide isoprene and monoterpene emission rate potentials within acceptable limits for the dominant plant species at these three woodland sites. 21 refs., 5 tabs., 2 figs.

  13. Metabolic responses and β-carotene production by the unicellular green alga Dunaliella salina exposed to leaf extracts

    Directory of Open Access Journals (Sweden)

    Alireza Einali

    Full Text Available ABSTRACT The present work investigated the effects of aqueous extracts of eucalyptus ( Eucalyptus globulus and elderberry ( Sambucus ebulus leaves on β-carotene productivity in Dunaliella salina, a green microalga. Leaf extracts from eucalyptus have greater amounts of phenolics and flavonoids, as well as greater ferric reducing antioxidant potential than elderberry. The extracts of both species greatly inhibited growth of algal suspensions. However, chlorophyll and β-carotene concentration increased in cells treated with leaf extracts, and the highest values were detected in 1 % eucalyptus and 2 % elderberry extracts. Fresh weight, total sugar, and protein content significantly increased following exposure of cells to different doses of leaf extracts. However, in doses containing more than 2 % eucalyptus, the upward trend for total sugar and protein ceased and remained statistically unchanged. These results suggest that metabolic modifications enable D. salina cells to tolerate the stress induced by the leaf extracts through allocating carbon flux to the synthesis of osmolytes and putative antioxidant molecules (e.g. sugars and β-carotene. Therefore, the use of leaf extracts holds potential to be a promising and effective way to improve D. salina cultivation for β-carotene production and other biotechnological and industrial applications.

  14. How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves

    Science.gov (United States)

    Zhang, Chen; Sanders, Johan P. M.; Xiao, Ting T.; Bruins, Marieke E.

    2015-01-01

    Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured) protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further improvements in alkaline protein biorefinery. Protein extraction yield was studied for correlation to morphology of leaf tissue structure, protein solubility and hydrolysis degree, and yields of non-protein components obtained at various conditions. Alkaline protein extraction was not facilitated by increased solubility or hydrolysis of protein, but positively correlated to leaf tissue disruption. HG pectin, RGII pectin, and organic acids were extracted before protein extraction, which was followed by the extraction of cellulose and hemi-cellulose. RGI pectin and lignin were both linear to protein yield. The yields of these two components were 80% and 25% respectively when 95% protein was extracted, which indicated that RGI pectin is more likely to be the key limitation to leaf protein extraction. An integrated biorefinery was designed based on these results. PMID:26200774

  15. How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves.

    Directory of Open Access Journals (Sweden)

    Chen Zhang

    Full Text Available Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further improvements in alkaline protein biorefinery. Protein extraction yield was studied for correlation to morphology of leaf tissue structure, protein solubility and hydrolysis degree, and yields of non-protein components obtained at various conditions. Alkaline protein extraction was not facilitated by increased solubility or hydrolysis of protein, but positively correlated to leaf tissue disruption. HG pectin, RGII pectin, and organic acids were extracted before protein extraction, which was followed by the extraction of cellulose and hemi-cellulose. RGI pectin and lignin were both linear to protein yield. The yields of these two components were 80% and 25% respectively when 95% protein was extracted, which indicated that RGI pectin is more likely to be the key limitation to leaf protein extraction. An integrated biorefinery was designed based on these results.

  16. Nanoparticle-Incorporated PDMS Film as an Improved Performance SPME Fiber for Analysis of Volatile Components of Eucalyptus Leaf

    Directory of Open Access Journals (Sweden)

    Parviz Aberoomand Azar

    2013-01-01

    Full Text Available A new fabrication strategy was proposed to prepare polydimethylsiloxane (PDMS- coated solid-phase microextraction (SPME on inexpensive and unbreakable Cu fiber. PDMS was covalently bonded to the Cu substrate using self-assembled monolayer (SAM of (3-mercaptopropyltrimethoxysilane (3MPTS as binder. To increase the performance of the fiber, the incorporation effect of some nanomaterials including silica nanoparticles (NPs, carbon nanotubes (CNTs, and carboxylated carbon nanotubes (CNT-COOH to PDMS coating was compared. The surface morphology of the prepared fibers was characterized by scanning electron microscopy (SEM, and their applicability was evaluated through the extraction of some volatile organic compounds (VOCs of Eucalyptus leaf in headspace mode, and parameters affecting the extraction efficiency including extraction temperature and extraction time were optimized. Extracted compounds were analyzed by GC-MS instrument. The results obtained indicated that prepared fibers have some advantages relative to previously prepared SPME fibers, such as higher thermal stability and improved performance of the fiber. Also, results showed that SPME is a fast, simple, quick, and sensitive technique for sampling and sample introduction of Eucalyptus VOCs.

  17. Lantana camara Linn leaf extract mediated green synthesis of gold nanoparticles and study of its catalytic activity

    Science.gov (United States)

    Dash, Shib Shankar; Bag, Braja Gopal; Hota, Poulami

    2015-03-01

    A facile one-step green synthesis of stable gold nanoparticles (AuNPs) has been described using chloroauric acid (HAuCl4) and the leaf extract of Lantana camara Linn (Verbenaceae family) at room temperature. The leaf extract enriched in various types of plant secondary metabolites is highly efficient for the reduction of chloroaurate ions into metallic gold and stabilizes the synthesized AuNPs without any additional stabilizing or capping agents. Detailed characterizations of the synthesized gold nanoparticles were carried out by surface plasmon resonance spectroscopy, transmission electron microscopy, dynamic light scattering, Zeta potential, X-ray diffraction and Fourier transform-infrared spectroscopy studies. The synthesized AuNPs have been utilized as a catalyst for the sodium borohydride reduction of 4-nitrophenol to 4-aminophenol in water at room temperature under mild reaction condition. The kinetics of the reduction reaction has been studied spectrophotometrically.

  18. Green synthesis, characterization and antimicrobial activities of zinc oxide nanoparticles from the leaf extract of Azadirachta indica (L.)

    Energy Technology Data Exchange (ETDEWEB)

    Elumalai, K. [Department of Physics, Annamalai University, Annamalai Nagar 608002 (India); Velmurugan, S., E-mail: drvelmurganphy@gmail.com [Department of Engineering Physics (FEAT), Annamalai University, Annamalai Nagar 608 002 (India)

    2015-08-01

    Graphical abstract: - Highlights: • Phenolic acid and flavonoid compounds play a major role in bioreduction reaction confirmed by FT-IR. • PL spectrum identified peaks were located in the range of the blue-violet spectrum. • XRD pattern confirmed ZnO hexagonal phase (wurtzite structure). • The result of (AFM) images depicted polycrystalline with porous nature of ZnO NPs. • Antimicrobial activities of green synthesized ZnO NPs were more potent than Bare ZnO and leaf of A. indica. - Abstract: The synthesis of metal and semiconductor nanoparticles is an expanding research area due to the potential applications in the development of novel technologies. Especially, biologically synthesized nanomaterial has become an important branch of nanotechnology. The present work, described the synthesis of zinc oxide nanoparticles (ZnO NPs) using leaf aqueous extract of Azadirachta indica (L.) and its antimicrobial activities. The nanoparticles was obtain characterized by UV–Vis spectroscopy, Photoluminescence (PL), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) analysis, Energy dispersive X-ray analysis (EDAX), Field emission scanning electron microscopy (FESEM) and Atomic force microscope (AFM) analysis. In this study we also investigated antimicrobial activity of green synthesized ZnO NPs. The results depicted concentration of ZnO NPs was increased (50, 100, 200 μg/mL) and also increase in antimicrobial activities was due to the increase of H{sub 2}O{sub 2} concentration from the surface of ZnO. However, green synthesized ZnO NPs was more potent than Bare ZnO and leaf of A. indica. Finally concluded the zinc oxide nanoparticles exhibited an interesting antimicrobial activity with both Gram positive and Gram negative bacterial and yeast at micromolar concentration.

  19. Interactive influence of leaf age, light intensity, and girdling on green ash foliar chemistry and emerald ash borer development.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-07-01

    Biotic and abiotic environmental factors affect plant nutritional quality and defensive compounds that confer plant resistance to herbivory. Influence of leaf age, light availability, and girdling on foliar nutrition and defense of green ash (Fraxinus pennsylvanica Marsh) was examined in this study. Longevity of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adults reared on green ash foliage subjected to these factors was assayed. Mature leaves generally were more nutritious with greater amino acids and a greater ratio of protein to non-structural carbohydrate (P:C) than young leaves, in particular when trees were grown in shade. On the other hand, mature leaves had lower amounts of trypsin and chymotrypsin inhibitors, and total phenolics compared to young leaves. Lower defense of mature leaves alone, or along with higher nutritional quality may lead to increased survival and longevity of emerald ash borer feeding on mature leaves. Sunlight reduced amino acids and P:C ratio, irrespective of leaf age and girdling, and elevated total protein of young foliage, but not protein of mature leaves. Sunlight also dramatically increased all investigated defensive compounds of young, but not mature leaves. Girdling reduced green ash foliar nutrition, especially, of young leaves grown in shade and of mature leaves grown in sun. However emerald ash borer performance did not differ when fed leaves from trees grown in sun or shade, or from girdled or control trees. One explanation is that emerald ash borer reared on lower nutritional quality food may compensate for nutrient deficiency by increasing its consumption rate. The strong interactions among leaf age, light intensity, and girdling on nutrition and defense highlight the need for caution when interpreting data without considering possible interactions.

  20. Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

    Science.gov (United States)

    Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

  1. Effect of post-fermentation and packing stages on the volatile composition of Spanish-style green table olives.

    Science.gov (United States)

    Sánchez, Antonio Higinio; López-López, Antonio; Cortés-Delgado, Amparo; Beato, Víctor Manuel; Medina, Eduardo; de Castro, Antonio; Montaño, Alfredo

    2018-01-15

    The volatile profile of Spanish-style green table olives after fermentation and the changes in volatile compounds that occurred as a result of the post-fermentation and subsequent packing stage were explored by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS). Three olive cultivars (Manzanilla, Gordal, and Hojiblanca) were processed and olive samples were taken at three different times throughout the elaboration: after fermentation, after post-fermentation, and after packing. A total of 132 volatile compounds were identified, including 10 phenols, 25 alcohols, 11 acids, 39 esters, 8 hydrocarbons, 14 carbonyl compounds, 17 terpenes, and 6 other compounds. A varying number of compounds from each chemical family underwent significant changes because of the post-fermentation and packing stages. Among them, some typical reaction products of lipid oxidation (e.g. (E)-2-decenal and (E,E)-2,4-decadienal) increased with the post-fermentation in Manzanilla cultivar, and also as a result of packing in all three cultivars. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Air quality and health effects of biogenic volatile organic compounds emissions from urban green spaces and the mitigation strategies.

    Science.gov (United States)

    Ren, Yuan; Qu, Zelong; Du, Yuanyuan; Xu, Ronghua; Ma, Danping; Yang, Guofu; Shi, Yan; Fan, Xing; Tani, Akira; Guo, Peipei; Ge, Ying; Chang, Jie

    2017-11-01

    Biogenic volatile organic compounds (BVOCs) emissions lead to fine particulate matter (PM 2.5 ) and ground-level ozone pollution, and are harmful to human health, especially in urban areas. However, most BVOCs estimations ignored the emissions from urban green spaces, causing inaccuracies in the understanding of regional BVOCs emissions and their environmental and health effects. In this study, we used the latest local vegetation datasets from our field survey and applied an estimation model to analyze the spatial-temporal patterns, air quality impacts, health damage and mitigating strategies of BVOCs emissions in the Greater Beijing Area. Results showed that: (1) the urban core was the hotspot of regional BVOCs emissions for the highest region-based emission intensity (3.0 g C m -2 yr -1 ) among the 11 sub-regions; (2) urban green spaces played much more important roles (account for 62% of total health damage) than rural forests in threating human health; (3) BVOCs emissions from green spaces will more than triple by 2050 due to urban area expansion, tree growth and environmental changes; and (4) adopting proactive management (e.g. adjusting tree species composition) can reduce 61% of the BVOCs emissions and 50% of the health damage related to BVOCs emissions by 2050. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Study on flavour volatiles of γ-aminobutyric acid (GABA) green tea ...

    African Journals Online (AJOL)

    The volatile components of γ-aminobutyric acid (GABA) tea produced by two different kinds of technological process separately namely: vacuum and water immersion were studied. It was shown by the sensory evaluation that the color of the soup and the extracted leaves of GABA tea were similar to that of the oolong tea, ...

  4. Comparison of growth, yield and fiber quality of the obsolete SA30 yellow leaf with four sets of modern yellow and green leaf near isogenic cotton (Gossypium hirsutum L.) lines

    Science.gov (United States)

    The Virescent Yellow leaf cotton line Seed Accession 30 (SA30) was crossed with four modern parental lines (DP5690, DES119, SG747 and MD51ne) to develop four sets of near isogenic lines (NILs) segregating for green and yellow leaves. Comparisons of these lines were made in the field in a two year re...

  5. Few long-term effects of simulated climate change on volatile organic compound emissions and leaf chemistry of three subarctic dwarf shrubs

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Rinnan, Åsmund; Faubert, Patrick

    2011-01-01

    Climate change is exposing arctic ecosystems to higher temperature, increased nutrient availability and shading due to the increasing cloud cover and the expanding forests. In this work, we assessed how these factors affect the emissions of biogenic volatile organic compounds (BVOCs) from three......-selinene from S. phylicifolia. The shading treatment obtained by dome-shaped hessian tents did not cause clear long-term changes in leaf chemistry or BVOC emissions. The only observed change was a marginally significant increase in sesquiterpene emissions from B. nana. When the treatment effects on long...

  6. Eco-friendly and green synthesis of silver nanoparticles using leaf extract of Strychnos potatorum Linn.F. and their bactericidal activities

    OpenAIRE

    Kagithoju, Srikanth; Godishala, Vikram; Nanna, Rama Swamy

    2014-01-01

    Inspired green synthesis of metallic nanoparticles is evolving as an important branch of nanotechnology. Traditionally these are manufactured by wet chemical methods which require toxic and flammable chemicals. We report for the first time an economic and eco-friendly green synthesis of silver nanoparticles using Strychnos potatorum aqueous leaf extract from 3 mM silver nitrate solution. Nanoparticles thus formed are confirmed and characterized by using UV–Vis absorption spectroscopy, SEM and...

  7. Leaf Volatile Compounds and Associated Gene Expression during Short-Term Nitrogen Deficient Treatments in Cucumis Seedlings

    Directory of Open Access Journals (Sweden)

    Jie Deng

    2016-11-01

    Full Text Available Nitrogen (N is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially (E-2-hexanal and (E,Z-2,6-nonadienal. (E-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas (E,Z-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19, CsLOX20, and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber.

  8. How does Germany's green energy policy affect electricity market volatility? An application of conditional autoregressive range models

    International Nuclear Information System (INIS)

    Auer, Benjamin R.

    2016-01-01

    Based on a dynamic model for the high/low range of electricity prices, this article analyses the effects of Germany's green energy policy on the volatility of the electricity market. Using European Energy Exchange data from 2000 to 2015, we find rather high volatility in the years 2000–2009 but also that the weekly price range has significantly declined in the period following the year 2009. This period is characterised by active regulation under the Energy Industry Law (EnWG), the EU Emissions Trading Directive (ETD) and the Renewable Energy Law (EEG). In contrast to the preceding period, price jumps are smaller and less frequent (especially for day-time hours), implying that current policy measures are effective in promoting renewable energies while simultaneously upholding electricity market stability. This is because the regulations strive towards a more and more flexible and market-oriented structure which allows better integration of renewable energies and supports an efficient alignment of renewable electricity supply with demand. - Highlights: • We estimate a CARR model for German electricity price data. • We augment the model by dummies capturing important regulations. • We find a significant decline in the price range after the year 2009. • This implies effective price stabilisation by German energy policy.

  9. Can volatiles emitted by compost during spawn run be used to detect green mould infection early?

    NARCIS (Netherlands)

    Johan, B.; Rutjens, J.; Mumm, R.

    2011-01-01

    In recent years green mould (Trichoderma aggressivum) has presented big problems to the Dutch mushroom industry. T. aggressivum infects compost at a very early stage and in the Dutch situation infection most likely takes place at the compost yard. Even though compost producers in the Netherlands are

  10. Green synthesis of silver nanoparticles using Alternanthera dentata leaf extract at room temperature and their antimicrobial activity.

    Science.gov (United States)

    Kumar, Deenadayalan Ashok; Palanichamy, V; Roopan, Selvaraj Mohana

    2014-06-05

    A green rapid biogenic synthesis of silver nanoparticles AgNPs using Alternanthera dentata (A. dentata) aqueous extract was demonstrated in this present study. The formation of silver nanoparticles was confirmed by Surface Plasmon Resonance (SPR) at 430nm using UV-visible spectrophotometer. The reduction of silver ions to silver nanoparticles by A. dentata extract was completed within 10min. Synthesized nanoparticles were characterized using UV-visible spectroscopy; Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy (TEM). The extracellular silver nanoparticles synthesis by aqueous leaf extract demonstrates rapid, simple and inexpensive method comparable to chemical and microbial methods. The colloidal solution of silver nanoparticles were found to exhibit antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia and, Enterococcus faecalis. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Green synthesis of silver nanoparticles from Moringa oleifera leaf extracts and its antimicrobial potential

    Science.gov (United States)

    Moodley, Jerushka S.; Babu Naidu Krishna, Suresh; Pillay, Karen; Sershen; Govender, Patrick

    2018-03-01

    In this study we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Moringa oleifera using sunlight irradiation as primary source of energy, and its antimicrobial potential. Silver nanoparticle formation was confirmed by surface plasmon resonance at 450 nm and 440 nm, respectively for both fresh and freeze-dried leaf samples. Crystanality of AgNPs was confirmed by transmission electron microscopy, scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis. FTIR spectroscopic analysis suggested that flavones, terpenoids and polysaccharides predominate and are primarily responsible for the reduction and subsequent capping of AgNPs. X-ray diffraction analysis also demonstrated that the size range of AgNPs from both samples exhibited average diameters of 9 and 11 nm, respectively. Silver nanoparticles showed antimicrobial activity on both bacterial and fungal strains. The biosynthesised nanoparticle preparations from M. oleifera leaf extracts exhibit potential for application as broad-spectrum antimicrobial agents.

  12. Extraction and Antibacterial Properties of Thyme Leaf Extracts: Authentic Practice of Green Chemistry

    Science.gov (United States)

    Purcell, Sean C.; Pande, Prithvi; Lin, Yingxin; Rivera, Ernesto J.; Paw U, Latisha; Smallwood, Luisa M.; Kerstiens, Geri A.; Armstrong, Laura B.; Robak, MaryAnn T.; Baranger, Anne M.; Douskey, Michelle C.

    2016-01-01

    In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ("Thymus vulgaris") in an authentic, research-like environment. This multi-week experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students…

  13. Green synthesis of Fe nanoparticles using eucalyptus leaf extracts for treatment of eutrophic wastewater

    International Nuclear Information System (INIS)

    Wang, Ting; Jin, Xiaoying; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-01-01

    Iron nanoparticles were firstly synthesized through a one-step room-temperature biosynthetic route using eucalyptus leaf extracts (EL-Fe NPs). Scanning electron microscopy (SEM) and X-ray energy-dispersive spectrometer (EDS) confirmed the successful synthesis of the spheroidal iron nanoparticles. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectrometer (FTIR) indicated that some polyphenols are bound to the surfaces of EL-Fe NPs as a capping/stabilizing agent. Reactivity of EL-Fe NPs was evaluated for the treatment of swine wastewater and results indicated that 71.7% of total N and 84.5% of COD were removed, respectively. This demonstrated the tremendous potential of EL-Fe NPs for in situ remediation of eutrophic wastewater. - Highlights: •Fe NPs were firstly synthesized through a one-step using eucalyptus leaf extracts. •Fe NPs was evaluated by remediating swine wastewater. •71.7% of total N and 84.5% of COD was removed. •Fe NPs for in situ remediation of eutrophic wastewater

  14. Green synthesis of Fe nanoparticles using eucalyptus leaf extracts for treatment of eutrophic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ting; Jin, Xiaoying [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian (China); Chen, Zuliang, E-mail: Zuliang.chen@unisa.edu.au [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian (China); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia); Megharaj, Mallavarapu; Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia)

    2014-01-01

    Iron nanoparticles were firstly synthesized through a one-step room-temperature biosynthetic route using eucalyptus leaf extracts (EL-Fe NPs). Scanning electron microscopy (SEM) and X-ray energy-dispersive spectrometer (EDS) confirmed the successful synthesis of the spheroidal iron nanoparticles. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectrometer (FTIR) indicated that some polyphenols are bound to the surfaces of EL-Fe NPs as a capping/stabilizing agent. Reactivity of EL-Fe NPs was evaluated for the treatment of swine wastewater and results indicated that 71.7% of total N and 84.5% of COD were removed, respectively. This demonstrated the tremendous potential of EL-Fe NPs for in situ remediation of eutrophic wastewater. - Highlights: •Fe NPs were firstly synthesized through a one-step using eucalyptus leaf extracts. •Fe NPs was evaluated by remediating swine wastewater. •71.7% of total N and 84.5% of COD was removed. •Fe NPs for in situ remediation of eutrophic wastewater.

  15. Biological application of green silver nanoparticle synthesized from leaf extract of Rauvolfi serpentina Benth

    Directory of Open Access Journals (Sweden)

    Sudipta Panja

    2016-07-01

    Full Text Available Objective: To synthesize silver nanoparticles (AgNPs from the leaf extract of Rauvolfia serpentina Benth and examination of their various biological activities. Methods: An ecofriendly, easy, one step, non-toxic and inexpensive approach is used, where aqueous plant extract acts as a reducing as well as stabilizing agent of AgNPs. The nanoparticles were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy analysis. Results: Surface plasmon resonance of the nanoparticles was observed at 427 nm in UV-vis spectroscopy. Fourier transform infrared spectroscopy result confirms that the plant extract acts as the reducing as well as the capping agent of the AgNPs. Transmission electron microscopy indicated that the synthesized nanoparticles are spherical in shape and approximately 7–10 nm in size, whereas the crystalline nature with face-centered cubic structure of the AgNPs was detected by X-ray diffraction analysis. Presence of silver in the AgNPs is 31.43% by weight, as confirmed by energy-dispersive X-ray spectroscopy. The synthesized AgNPs have antimicrobial activities against human pathogenic microorganisms. It also shows larvicidal activity and cytotoxicity against HeLa, MCF-7 cell lines. Conclusions: Synthesized spherical shaped AgNPs from the leaf extract of Rauvolfia serpentina Benth have antimicrobial and larvicidal activities as well as cytotoxicity against HeLa and MCF-7 cell lines.

  16. Rapid green synthesis of spherical gold nanoparticles using Mangifera indica leaf

    Science.gov (United States)

    Philip, Daizy

    2010-11-01

    This paper reports the rapid biological synthesis of spherical gold nanoparticles at room temperature using fresh/dry leaf extract of Mangifera indica. This is a simple, cost-effective, stable for long time and reproducible aqueous synthesis method to obtain a self-assembly of nearly monodispersed Au nanoparticles of size ˜20 nm and 17 nm. The nanoparticles were obtained within 2 min of addition of the extract to the solution of HAuCl 4·3H 2O and the colloid is found to be stable for more than 5 months. Smaller and more uniformly distributed particles could be obtained with dried leaf extract. The nanoparticles obtained are characterized by UV-vis, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Crystalline nature of the nanoparticles in the fcc structure is confirmed by the peaks in the XRD pattern corresponding to (1 1 1), (2 0 0), (2 2 0), (3 1 1) and (2 2 2) planes, bright circular spots in the selected area electron diffraction (SAED) and clear lattice fringes in the high-resolution TEM image. The possible biomolecules responsible for efficient stabilization are suggested by studying the FTIR spectrum of the sample. This environmentally benign method provides much faster synthesis and colloidal stability comparable to those of chemical reduction.

  17. Evaluation of antibacterial activities of silver nanoparticles green-synthesized using pineapple leaf (Ananas comosus).

    Science.gov (United States)

    Emeka, Elemike Elias; Ojiefoh, Oseghale Charles; Aleruchi, Chuku; Hassan, Labulo Ayomide; Christiana, Owoseni Mojisola; Rebecca, Mfon; Dare, Enock Olugbenga; Temitope, Adesuji Elijah

    2014-02-01

    Pineapple leaf was used in this study for the synthesis of silver nanoparticles based on the search for sustainable synthetic means. Indeed, this offered an economical and sustainable synthetic route relative to expensive and toxic chemical methods. The leaf extract was used and the corresponding nanoparticles obtained were subjected to UV-vis analysis at different times. The UV-vis was used to monitor the silver nanoparticle formation through sampling at time intervals. The formation of silver nanoparticles was apparently displayed within 2 min with evidence of surface plasmon bands (SPB) between 440 and 460 nm. The crystals was equally characterized using FTIR, X-ray diffraction methods and TEM. The different results obtained suggested the appearance of silver nanoparticles (SNPs) as determined by the process parameters with a particle size of 12.4 nm. The sample was further screened against Staphylococcus aureus, Streptococcus pneumoniae, Proteus mirabilis and Escherichia coli using Gentamicin as control. From the results, there is evidence of inhibition towards bacteria growth. It can now be inferred from the studies that biosynthesis of nanoparticles could be a gateway to our numerous health issues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Green synthesis of silver nanoparticles using a Melissa officinalis leaf extract with antibacterial properties

    Directory of Open Access Journals (Sweden)

    Álvaro de Jesús Ruíz-Baltazar

    Full Text Available The exceptional properties of the silver nanoparticles offer several applications in the biomedicine field. The development of antibiotics which are clinically useful against bacteria and drug resistant microorganisms, it is one of the main approaches of silver nanoparticles. However, it is necessary to develop environmentally friendly methods for their synthesis. In this sense, the main objective of this work is focused on to propose a simplified and efficient green synthesis of silver nanoparticles with proven antibacterial properties. The green synthesis route is based on the use of the Melissa officinalis as reducing agent of the silver ions in aqueous solution at room temperature. Complementary, the antibacterial activity of the silver nanoparticles against Staphylococcus aureus and Escherichia coli was confirmed. The silver nanoparticles obtained were characterized by transmission electron microscopy, X-ray diffraction, UV–vis, Raman and FT-IR spectroscopy. The observed results suggested that using Melissa officinalis, it is possible to performed silver nanoparticles with controlled characteristics and with significant inhibitory activity against the Staphylococcus aureus and Escherichia coli. Keywords: Green synthesis, Nanoparticles, Antibacterial effect

  19. Green synthesis of silver nanoparticles by Ricinus communis var. carmencita leaf extract and its antibacterial study

    Science.gov (United States)

    Ojha, Sunita; Sett, Arghya; Bora, Utpal

    2017-09-01

    In this study, we report synthesis of silver nanoparticles (RcAgNPs) from silver nitrate solution using methanolic leaf extract of Ricinus communis var. carmencita. The polyphenols present in the leaves reduce Ag++ ions to Ag0 followed by a color change. Silver nanoparticle formation was ensured by surface plasmon resonance between 400 nm to 500 nm. Crystallinity of the synthesized nanoparticles was confirmed by UHRTEM, SAED and XRD analysis. The capping of phytochemicals and thermal stability of RcAgNPs were assessed by FTIR spectra and TGA analysis, respectively. It also showed antibacterial activity against both gram positive and gram negative strains. RcAgNPs were non-toxic against normal cell line (mouse fibroblast cell line L929) at lower concentrations (80 µg ml-1).

  20. Biofumigation for control of pale potato cyst nematodes: activity of brassica leaf extracts and green manures on Globodera pallida in vitro and in soil.

    Science.gov (United States)

    Lord, James S; Lazzeri, Luca; Atkinson, Howard J; Urwin, Peter E

    2011-07-27

    The effects of brassica green manures on Globodera pallida were assessed in vitro and in soil microcosms. Twelve of 22 brassica accessions significantly inhibited the motility of G. pallida infective juveniles in vitro. Green manures of selected brassicas were then incorporated into soil containing encysted eggs of G. pallida. Their effect on egg viability was estimated by quantifying nematode actin 1 mRNA by RT-qPCR. The leaf glucosinolate profiles of the plants were determined by high-performance liquid chromatography. Three Brassica juncea lines (Nemfix, Fumus, and ISCI99) containing high concentrations of 2-propenyl glucosinolate were the most effective, causing over 95% mortality of encysted eggs of G. pallida in polyethylene-covered soil. The toxic effects of green manures were greater in polyethylene-covered than in open soil. Toxicity in soil correlated with the concentration of isothiocyanate-producing glucosinolate but not total glucosinolate in green manures.

  1. Allelopathic effects of eucalyptus camaldulensis leaf leachate on the growth of wheat and green gram and its control by farm yard manure

    International Nuclear Information System (INIS)

    Ibrahim, S.; Bibi, S.

    2012-01-01

    Farm Yard Manure (FYM) significantly reduced the allelopathic effects of Eucalyptus camaldulensis leachate. This influence was studied on morphological and physiological aspect of two taxonomically different plants (wheat and green gram). E. camaldulensis aqueous leachate applied (4), 1% and 5% alone and together with FYM and the results showed that E. camaldulensis leaf leachate had inhibitory effects on wheat growth, while promoted shoot and root growth in green gram when supplied in low concentration. The combined effects of litter and FYM reduced the inhibitory effects of leachate and supported the growth of both plants. These results suggested that, if both studied crops have to be cultivated in an agricultural land surrounded by E. camaldulensis tree, the possible growth rate could be supported by the application of FYM. But in the absence of this support, the plant growth was significantly arrested due to allelopathic effect of E. ctunaldulensis leaf leachate. (author)

  2. Allelopathic effects of eucalyptus camaldulensis leaf leachate on the growth of wheat and green gram and its control by farm yard manure

    International Nuclear Information System (INIS)

    Ibrahim, S.; Bibi, S.

    2012-01-01

    Farm Yard Manure (FYM) significantly reduced the allelopathic effects of Eucalyptus camaldulensis leachate. This influence was studied on morphological and physiological aspect of two taxonomically different plants (wheat and green gram). E. camaldtllensis aqueous leachate applied at the rate of 1% and 5% alone and together with FYM and the results showed that E. camaldulensis leaf leachate had inhibitory effects on wheat growth, while promoted shoot and root growth in green gram when supplied in low concentration. The combined effects of litter and FYM reduced the inhibitory effects of leachate and supported the growth of both plants. These results suggested that, if both studied crops have to be cultivated in an agricultural land surrounded by E. camaldulensis tree, the possible growth rate could be supported by the application Of FYM. But in the absence of this support, the plant growth was significantly arrested due to allelopathic effect of E. camaldulensis leaf leachate. (author)

  3. One-step green synthesis and characterization of leaf extract-mediated biocompatible silver and gold nanoparticles from Memecylon umbellatum

    Science.gov (United States)

    Arunachalam, Kantha D; Annamalai, Sathesh Kumar; Hari, Shanmugasundaram

    2013-01-01

    In this experiment, green-synthesized silver and gold nanoparticles were produced rapidly by treating silver and gold ions with an extract of Memecylon umbellatum leaf. The reaction process was simple and easy to handle, and was monitored using ultraviolet-visible spectroscopy. The effect of the phytochemicals present in M. umbellatum, including saponins, phenolic compounds, phytosterols, and quinones, on formation of stable silver and gold nanoparticles was investigated by Fourier-transform infrared spectroscopy. The morphology and crystalline phase of the nanoparticles were determined by transmission electron microscopy and energy-dispersive x-ray spectroscopy. The results indicate that the saponins, phytosterols, and phenolic compounds present in the plant extract play a major role in formation of silver and gold nanoparticles in their respective ions in solution. The characteristics of the nanoparticles formed suggest application of silver and gold nanoparticles as chemical sensors in the future. Given the simple and eco-friendly approach for synthesis, these nanoparticles could easily be commercialized for large-scale production. PMID:23569372

  4. Microwave assisted facile green synthesis of silver and gold nanocatalysts using the leaf extract of Aerva lanata

    Science.gov (United States)

    Joseph, Siby; Mathew, Beena

    2015-02-01

    Herein, we report a simple microwave assisted method for the green synthesis of silver and gold nanoparticles by the reduction of aqueous metal salt solutions using leaf extract of the medicinal plant Aerva lanata. UV-vis., FTIR, XRD, and HR-TEM studies were conducted to assure the formation of nanoparticles. XRD studies clearly confirmed the crystalline nature of the synthesized nanoparticles. From the HR-TEM images, the silver nanoparticles (AgNPs) were found to be more or less spherical and gold nanoparticles (AuNPs) were observed to be of different morphology with an average diameter of 18.62 nm for silver and 17.97 nm for gold nanoparticles. In order to evaluate the effect of microwave heating upon rate of formation, the synthesis was also conducted under ambient condition without the assistance of microwave radiation and the former method was found to be much faster than the later. The synthesized nanoparticles were used as nanocatalysts in the reduction of 4-nitrophenol to 4-aminophenol by NaBH4.

  5. The Role of Leaf Volatiles of Ludwigia octovalvis (Jacq.) Raven in the Attraction of Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Mitra, Saubhik; Karmakar, Amarnath; Mukherjee, Abhishek; Barik, Anandamay

    2017-07-01

    Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol.

  6. Nitrogen Limited Red and Green Leaf Lettuce Accumulate Flavonoid Glycosides, Caffeic Acid Derivatives, and Sucrose while Losing Chlorophylls, ?-Carotene and Xanthophylls

    OpenAIRE

    Becker, Christine; Urli?, Branimir; Juki? ?pika, Maja; Kl?ring, Hans-Peter; Krumbein, Angelika; Baldermann, Susanne; Goreta Ban, Smiljana; Perica, Slavko; Schwarz, Dietmar

    2015-01-01

    Reduction of nitrogen application in crop production is desirable for ecological and health-related reasons. Interestingly, nitrogen deficiency can lead to enhanced concentrations of polyphenols in plants. The reason for this is still under discussion. The plants' response to low nitrogen concentration can interact with other factors, for example radiation intensity. We cultivated red and green leaf lettuce hydroponically in a Mediterranean greenhouse, supplying three different levels of nitr...

  7. Physicochemical properties of pectin from green jelly leaf (Cyclea barbata Miers).

    Science.gov (United States)

    Yuliarti, O; Chong, S Y; Goh, K K T

    2017-10-01

    The water extract of Green Jelly leaves (GJL) obtained by crushing the leaves in water (1:40) was capable of forming a gel at room temperature. The composition of GJL consisted mainly of carbohydrate (∼70w/w), protein (∼13% w/w) and minerals (∼6% w/w). The mineral portion consisted of mainly calcium (∼1.2% w/w), zinc (∼0.12% w/w) and magnesium (∼0.11% w/w). The isolated polysaccharide fraction (∼42.6% w/w) consisted of mainly galacturonic acid (∼35.8% w/w) and neutral sugars (∼6.8% w/w), with a weight-average molecular weight of ∼4.4×10 5 g/mol. The results obtained by Fourier Transform Infra-Red (FTIR) showed that GJL polysaccharide fraction had a fairly similar FTIR fingerprint as the commercial low-methoxyl pectin (LMP). The degree of esterification of the polysaccharide changed drastically (from 97% to 10%) depending on the temperature used during the extraction process. The zeta potential of the extracted polysaccharide showed high negative charged as compared to the commercial LMP but close to sodium alginate. The study showed that the gelation was divalent cation-mediated and probably facilitated by the low degree of esterification which reduced steric hindrance from the methyl ester groups. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. TUNGRO DISEASE CONTROL THROUGH THE ELIMINATION VECTOR ROLE OF GREEN LEAF HOPPER WITH ENVIRONMENT FRIENDLY CONTROL

    Directory of Open Access Journals (Sweden)

    Dini Yuliani

    2017-12-01

    Full Text Available Green leafhopper (GLHplays an important role in tungro disease epidemics. Reduce the activity of GLHsuckasvectorsof tungro virus was effective to limit transmission of the virus. Integrated control of tungro disease may involve multiple components at once including using sambilata with entomopathogenicfungus Metarhiziumanisopliae. This research was conducted to determine the effect of sambilata and M.anisopliaein controlling the GLH as tungro virus vectors. The experiment was conducted in tungro endemic areas in Tanjungsiang,Subang District at dry season 2013 and wet season 2013/2014. Experiments using split plot design with four replications. The main plot was consists of GLH resistant varieties(IR66, tungro resistant varieties (Inpari 9, and check varieties(Ciherang. The subplots were M.anisopliae applications, sambilata, and control. Application was done on rice plant age 14, 28 and 42 days after planting (DAP.The results showed that the intensity of tungro on Ciherang showed the highest intensity compared toIR66 and Inpari9. Effect of entomopathogenic fungus M.anisopliae application to tungro disease showed a lower intensity compared with sambilata extracts and control. The intensity of tungro disease in farmers’ fields as a comparison of experiment was high enough on average between 1 until 69%. In general, the density of GLH population began to increase on the observation of 14 to 28 DAP. GLH population density was highest at 28 DAP. However, the population density of GLH decreased at 42 until 56 DAP.

  9. Comparison of male and female emerald ash borer (Coleoptera: Buprestidae) responses to phoebe oil and (Z)-3-hexanol lures in light green prism traps

    Science.gov (United States)

    Gary G. Grant; Therese M. Poland; Tina Ciaramitaro; D. Barry Lyons; Gene C. Jones

    2011-01-01

    We conducted trapping experiments for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Michigan, USA, and Ontario, Canada, to compare unbaited light green sticky prism traps with traps baited with phoebe oil, (Z)-3-hexenol (Z3-6:OH), or blends of other green leaf volatiles (GLVs) with Z3-6:OH. Traps were placed in the...

  10. Eco-friendly and green synthesis of silver nanoparticles using leaf extract of Strychnos potatorum Linn.F. and their bactericidal activities.

    Science.gov (United States)

    Kagithoju, Srikanth; Godishala, Vikram; Nanna, Rama Swamy

    2015-10-01

    Inspired green synthesis of metallic nanoparticles is evolving as an important branch of nanotechnology. Traditionally these are manufactured by wet chemical methods which require toxic and flammable chemicals. We report for the first time an economic and eco-friendly green synthesis of silver nanoparticles using Strychnos potatorum aqueous leaf extract from 3 mM silver nitrate solution. Nanoparticles thus formed are confirmed and characterized by using UV-Vis absorption spectroscopy, SEM and XRD measurements. The XRD and SEM analysis showed the average particle size of nanoparticles as 28 nm as well as revealed their (mixed, i.e., cubic and hexagonal) structure. Further, these green synthesized nanoparticles showed bactericidal activity against multidrug-resistant human pathogenic bacteria.

  11. An investigation of the leaf retention capacity, efficiency and mechanism for atmospheric particulate matter of five greening tree species in Beijing, China.

    Science.gov (United States)

    Liu, Jinqiang; Cao, Zhiguo; Zou, Songyan; Liu, Huanhuan; Hai, Xiao; Wang, Shihua; Duan, Jie; Xi, Benye; Yan, Guangxuan; Zhang, Shaowei; Jia, Zhongkui

    2018-03-01

    Urban trees have the potential to reduce air pollution, but the retention capacity and efficiency of different tree species for atmospheric particulate matter (PM) accumulation and the underlying mechanism hasn't been well understood. To select tree species with high air purification abilities, the supplementing ultrasonic cleaning (UC) procedure was first introduced into the conventional leaf cleaning methods [single water cleaning (WC) or plus brush cleaning (BC)] for eluting the leaf-retained PM. Further updates to the methodology were applied to investigate the retention capacity, efficiency, and mechanism for PM of five typical greening tree species in Beijing, China. Meanwhile, the particle size distribution of PM on the leaves, the PM retention efficiencies of easily removable (ERP), difficult-to-remove (DRP) and totally removable (TRP) particles on the leaf (AE leaf ), and the individual tree scales were estimated. The experimental leaf samples were collected from trees with similar sizes 4 (SDR) and 14days (LDR) after rainfall. When the leaves were cleaned by WC+BC, there was, on average, 29%-46% of the PM remaining on the leaves of different species, which could be removed almost completely if UC was supplemented. From SDR to LDR, the mass of the leaf-retained PM increased greatly, and the particle size distribution changed markedly for all species except for Sophorajaponica. Pinus tabuliformis retains particles with the largest average diameter (34.2μm), followed by Ginkgo biloba (20.5μm), Sabina chinensis (16.4μm), Salix babylonica (16.0μm), and S. japonica (13.1μm). S. japonica and S. chinensis had the highest AE leaf to retain the TRP and ERP of both PM 1 and PM 1-2.5 , respectively. Conversely, S. babylonica and P. tabuliformis could retain both TRP and ERP of PM 2.5-5 and PM 5-10 , and PM >10 and TSP with the highest AE leaf , respectively. In conclusion, our results could be useful in selecting greening tree species with high air purification

  12. Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles

    Science.gov (United States)

    The GLVs, such as 1-hexanol and (Z)-3-hexen-1-ol, elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relative weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactom...

  13. Characterization, antioxidant and antimicrobial activities of green synthesized silver nanoparticles from Psidium guajava L. leaf aqueous extracts.

    Science.gov (United States)

    Wang, Lu; Wu, Yanan; Xie, Jia; Wu, Sheng; Wu, Zhenqiang

    2018-05-01

    The green synthesis of nanoparticles has become increasingly promising due to their potential applications in nanomedicine and materials science. In this study, silver nanoparticles (P-AgNPs) were synthesized from aqueous extracts of P. guajava L. leaf. The synthesized silver nanoparticles were confirmed by UV-vis spectrophotometry at 438 nm. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zetasizer analyses showed that the average sizes of the P-AgNPs were 20-35 nm, 25 nm, and 25-35 nm, respectively. Element mapping analyses of the P-AgNPs were confirmed by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) analyses. Moreover, FTIR spectra of the synthesized P-AgNPs showed the presence of phyto constituents as capping agents. Zeta potential measurements (-20.17 mV) showed that the synthesized P-AgNPs had reasonably good stability. The in vitro antioxidant properties of the P-AgNPs were evaluated using two different methods. A highly efficient radical scavenging activity of P-AgNPs possessing IC 50 values of 52.53 ± 0.31 μg/mL (DPPH) and 55.10 ± 0.29 μg/mL (ABTS + ) were confirmed. At a concentration of 100 μg/mL, antimicrobial activity assays of the P-AgNPs showed significant inhibition against selected bacteria, S. cerevisiae, A. niger and R. oryzae, especially against Alcaligenes faecalis and Escherichia coli. The present study revealed that the low-cost and environmentally friendly synthesis of P-AgNPs can be widely used in biomedicine, water treatment or purification, and nanobiotechnology. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Evaluation of the effects of Olea europaea L. subsp. africana (Mill.) P.S. Green (Oleaceae) leaf methanol extract against castor oil-induced diarrhoea in mice.

    Science.gov (United States)

    Amabeoku, George J; Bamuamba, Kapinga

    2010-03-01

    Olea europaea L. subsp. africana (Mill.) P.S. Green is widely used in South Africa by traditional medicine practitioners to treat diarrhoea. However, little is known scientifically about this South African species in the treatment of diarrhoea. The main aim of the study therefore was to investigate the antidiarrhoeal effect of the leaf methanol extract of the plant species in mice. The antidiarrhoeal activity of the leaf methanol extract of O. europaea subsp. africana was studied using a castor oil-induced diarrhoeal test. The antipropulsive activity of the plant extract was also investigated using the charcoal meal transit test. Standard methods were used to investigate the acute toxicity and effect of O. europaea subsp. africana on castor oil-induced intraluminal fluid accumulation. Leaf methanol extract of O. europaea subsp. africana and loperamide, a standard antidiarrhoeal drug, significantly reduced the number of diarrhoeal episodes induced by castor oil, significantly decreased the stool mass, significantly delayed the onset of the diarrhoea and protected the animals against castor oil-induced diarrhoea. Both O. europaea subsp. africana and loperamide significantly decreased the gastrointestinal transit of charcoal meal and castor oil-induced intraluminal fluid accumulation in mice. The LD50 value was found to be 3475 mg/kg (p.o.). The results obtained suggest that the leaf methanol extract of O. europaea subsp. africana has an antidiarrhoeal property and that, given orally, it may be non-toxic and/or safe in mice.

  15. Sensory and Instrumental Flavor Changes in Green Tea Brewed Multiple Times

    Science.gov (United States)

    Lee, Jeehyun; Chambers, Delores; Chambers, Edgar

    2013-01-01

    Green teas in leaf form are brewed multiple times, a common selling point. However, the flavor changes, both sensory and volatile compounds, of green teas that have been brewed multiple times are unknown. The objectives of this study were to determine how the aroma and flavor of green teas change as they are brewed multiple times, to determine if a relationship exists between green tea flavors and green tea volatile compounds, and to suggest the number of times that green tea leaves can be brewed. The first and second brews of the green tea samples provided similar flavor intensities. The third and fourth brews provided milder flavors and lower bitterness and astringency when measured using descriptive sensory analysis. In the brewed liquor of green tea mostly linalool, nonanal, geraniol, jasmone, and β-ionone volatile compounds were present at low levels (using gas chromatography-mass spectrometry). The geraniol, linalool, and linalool oxide compounds in green tea may contribute to the floral/perfumy flavor. Green teas in leaf form may be brewed up to four times: the first two brews providing stronger flavor, bitterness, and astringency whereas the third and fourth brews will provide milder flavor, bitterness, and astringency. PMID:28239138

  16. A Green Protocol for Microwave-Assisted Extraction of Volatile Oil Terpenes from Pterodon emarginatus Vogel. (Fabaceae

    Directory of Open Access Journals (Sweden)

    Giuliana M. Vila Verde

    2018-03-01

    Full Text Available Microwave-assisted extraction of volatile oils (MAE potentially offers a more efficient and bio-sustainable method than conventional extraction by Clevenger apparatus (CE. This study aimed to optimise the MAE of the volatile oil from Pterodon emarginatus fruits and characterise the volatile compounds. A 23 full-factorial central composite design and response surface methodology were used to evaluate the effects of time (min, moisture (% and microwave power (W on the extraction yield. The process optimisation was based on the desirability function approach. The reaction time and moisture conditions were standardised in these analyses. The volatile oil composition was analysed by Gas Chromatography/Mass Spectrometry (GC/MS in order to compare techniques extractions influences. Microwave irradiation showed excellent performance for extraction of the volatile oil from Pterodon emarginatus and there were some advantages in compare to conventional method with respect to the time (14 times, energy (6 times, reagents amounts and waste formation. About chemical composition presents significant differences with the type of extraction. Caryophyllene (25.65% and trans-α-bisabolol (6.24% were identified as major components in MAE sample while caryophyllene (6.75% and γ-elemene (7.02% are the components with higher relative percentage in CE samples. The microwaves assisted process shown an increase of economic interested compounds present in volatile oil.

  17. Piper nigrum Leaf and Stem Assisted Green Synthesis of Silver Nanoparticles and Evaluation of Its Antibacterial Activity Against Agricultural Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Kanniah Paulkumar

    2014-01-01

    Full Text Available Utilization of biological materials in synthesis of nanoparticles is one of the hottest topics in modern nanoscience and nanotechnology. In the present investigation, the silver nanoparticles were synthesized by using the leaf and stem extract of Piper nigrum. The synthesized nanoparticle was characterized by UV-vis spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM, energy dispersive X-ray analysis (EDAX, and Fourier Transform Infrared Spectroscopy (FTIR. The observation of the peak at 460 nm in the UV-vis spectra for leaf- and stem-synthesized silver nanoparticles reveals the reduction of silver metal ions into silver nanoparticles. Further, XRD analysis has been carried out to confirm the crystalline nature of the synthesized silver nanoparticles. The TEM images show that the leaf- and stem-synthesized silver nanoparticles were within the size of about 7–50 nm and 9–30 nm, respectively. The FTIR analysis was performed to identify the possible functional groups involved in the synthesis of silver nanoparticles. Further, the antibacterial activity of the green-synthesized silver nanoparticles was examined against agricultural plant pathogens. The antibacterial property of silver nanoparticles is a beneficial application in the field of agricultural nanotechnology.

  18. Characterization, antibacterial, total antioxidant, scavenging, reducing power and ion chelating activities of green synthesized silver, copper and titanium dioxide nanoparticles using Artemisia haussknechtii leaf extract.

    Science.gov (United States)

    Alavi, Mehran; Karimi, Naser

    2017-12-12

    Recently, major problem related to pathogenic bacteria is augmentation of antibiotic resistance which has been changed treatment and recovery of millions of infectious patients. The present study reports an eco-friendly, rapid and easy method for synthesis of silver (Ag), copper (Cu) and titanium dioxide (TiO 2 ) nanoparticles (NPs) using Artemisia haussknechtii leaf aqueous extract with antibacterial activities against multi-drug resistance (MDR) bacteria species. Three different concentrations (0.001, 0.01 and 0.1 M) of AgNO 3 , CuSO 4 and TiO (OH) 2 were investigated for obtaining optimum NPs green synthesis. Total phenolic content, total flavonoid content of leaf extract and total antioxidant activity (DPPH) assay were determined as radical scavenging methods. UV-Visible spectroscopy, Fourier transform infrared spectroscopy analysis, X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscope and atomic force microscopy (AFM) were used due to NPs characterization. The size average of the Ag, Cu and TiO 2 NPs obtained were respectively 10.69 ± 5.55, 35.36 ± 44.4 and 92.58 ± 56.98 nm. In the case of antibacterial assay, disc diffusion assay, minimum inhibitory concentration, minimum bactericidal concentration, bacterial growth and morphology of four MDR species Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12258, Serratia marcescens ATTC13880 and Escherichia coli ATCC 25922 were evaluated. Results of this study demonstrated that A. haussknechtii leaf extract with various groups of phytochemicals such as phenols and flavonoids had suitable ability in green synthesis of Ag, Cu and TiO 2 NPs. Also, Ag and Cu NPs had more antibacterial activities compared to TiO 2 NPs.

  19. Nitrogen Limited Red and Green Leaf Lettuce Accumulate Flavonoid Glycosides, Caffeic Acid Derivatives, and Sucrose while Losing Chlorophylls, Β-Carotene and Xanthophylls.

    Science.gov (United States)

    Becker, Christine; Urlić, Branimir; Jukić Špika, Maja; Kläring, Hans-Peter; Krumbein, Angelika; Baldermann, Susanne; Goreta Ban, Smiljana; Perica, Slavko; Schwarz, Dietmar

    2015-01-01

    Reduction of nitrogen application in crop production is desirable for ecological and health-related reasons. Interestingly, nitrogen deficiency can lead to enhanced concentrations of polyphenols in plants. The reason for this is still under discussion. The plants' response to low nitrogen concentration can interact with other factors, for example radiation intensity. We cultivated red and green leaf lettuce hydroponically in a Mediterranean greenhouse, supplying three different levels of nitrogen (12 mM, 3 mM, 0.75 mM), either in full or reduced (-50%) radiation intensity. In both red and green lettuce, we found clear effects of the nitrogen treatments on growth characteristics, phenolic and photosynthetic compounds, nitrogen, nitrate and carbon concentration of the plants. Interestingly, the concentrations of all main flavonoid glycosides, caffeic acid derivatives, and sucrose increased with decreasing nitrogen concentration, whereas those of chlorophylls, β-carotene, neoxanthin, lactucaxanthin, all trans- and cis-violaxanthin decreased. The constitutive concentrations of polyphenols were lower in the green cultivar, but their relative increase was more pronounced than in the red cultivar. The constitutive concentrations of chlorophylls, β-carotene, neoxanthin, all trans- and cis-violaxanthin were similar in red and green lettuce and with decreasing nitrogen concentration they declined to a similar extent in both cultivars. We only detected little influence of the radiation treatments, e.g. on anthocyanin concentration, and hardly any interaction between radiation and nitrogen concentration. Our results imply a greater physiological plasticity of green compared to the red lettuce regarding its phenolic compounds. They support the photoprotection theory regarding anthocyanins as well as the theory that the deamination activity of phenylalanine ammonia-lyase drives phenylpropanoid synthesis.

  20. Nitrogen Limited Red and Green Leaf Lettuce Accumulate Flavonoid Glycosides, Caffeic Acid Derivatives, and Sucrose while Losing Chlorophylls, Β-Carotene and Xanthophylls

    Science.gov (United States)

    Becker, Christine; Urlić, Branimir; Jukić Špika, Maja; Kläring, Hans-Peter; Krumbein, Angelika; Baldermann, Susanne; Goreta Ban, Smiljana; Perica, Slavko; Schwarz, Dietmar

    2015-01-01

    Reduction of nitrogen application in crop production is desirable for ecological and health-related reasons. Interestingly, nitrogen deficiency can lead to enhanced concentrations of polyphenols in plants. The reason for this is still under discussion. The plants’ response to low nitrogen concentration can interact with other factors, for example radiation intensity. We cultivated red and green leaf lettuce hydroponically in a Mediterranean greenhouse, supplying three different levels of nitrogen (12 mM, 3 mM, 0.75 mM), either in full or reduced (-50%) radiation intensity. In both red and green lettuce, we found clear effects of the nitrogen treatments on growth characteristics, phenolic and photosynthetic compounds, nitrogen, nitrate and carbon concentration of the plants. Interestingly, the concentrations of all main flavonoid glycosides, caffeic acid derivatives, and sucrose increased with decreasing nitrogen concentration, whereas those of chlorophylls, β-carotene, neoxanthin, lactucaxanthin, all trans- and cis-violaxanthin decreased. The constitutive concentrations of polyphenols were lower in the green cultivar, but their relative increase was more pronounced than in the red cultivar. The constitutive concentrations of chlorophylls, β-carotene, neoxanthin, all trans- and cis-violaxanthin were similar in red and green lettuce and with decreasing nitrogen concentration they declined to a similar extent in both cultivars. We only detected little influence of the radiation treatments, e.g. on anthocyanin concentration, and hardly any interaction between radiation and nitrogen concentration. Our results imply a greater physiological plasticity of green compared to the red lettuce regarding its phenolic compounds. They support the photoprotection theory regarding anthocyanins as well as the theory that the deamination activity of phenylalanine ammonia-lyase drives phenylpropanoid synthesis. PMID:26569488

  1. Nitrogen Limited Red and Green Leaf Lettuce Accumulate Flavonoid Glycosides, Caffeic Acid Derivatives, and Sucrose while Losing Chlorophylls, Β-Carotene and Xanthophylls.

    Directory of Open Access Journals (Sweden)

    Christine Becker

    Full Text Available Reduction of nitrogen application in crop production is desirable for ecological and health-related reasons. Interestingly, nitrogen deficiency can lead to enhanced concentrations of polyphenols in plants. The reason for this is still under discussion. The plants' response to low nitrogen concentration can interact with other factors, for example radiation intensity. We cultivated red and green leaf lettuce hydroponically in a Mediterranean greenhouse, supplying three different levels of nitrogen (12 mM, 3 mM, 0.75 mM, either in full or reduced (-50% radiation intensity. In both red and green lettuce, we found clear effects of the nitrogen treatments on growth characteristics, phenolic and photosynthetic compounds, nitrogen, nitrate and carbon concentration of the plants. Interestingly, the concentrations of all main flavonoid glycosides, caffeic acid derivatives, and sucrose increased with decreasing nitrogen concentration, whereas those of chlorophylls, β-carotene, neoxanthin, lactucaxanthin, all trans- and cis-violaxanthin decreased. The constitutive concentrations of polyphenols were lower in the green cultivar, but their relative increase was more pronounced than in the red cultivar. The constitutive concentrations of chlorophylls, β-carotene, neoxanthin, all trans- and cis-violaxanthin were similar in red and green lettuce and with decreasing nitrogen concentration they declined to a similar extent in both cultivars. We only detected little influence of the radiation treatments, e.g. on anthocyanin concentration, and hardly any interaction between radiation and nitrogen concentration. Our results imply a greater physiological plasticity of green compared to the red lettuce regarding its phenolic compounds. They support the photoprotection theory regarding anthocyanins as well as the theory that the deamination activity of phenylalanine ammonia-lyase drives phenylpropanoid synthesis.

  2. green

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2011-02-01

    Full Text Available The “green” topic follows the “youngsters”, which is quite natural for the Russian language.Traditionally these words put together sound slightly derogatory. However, “green” also means fresh, new and healthy.For Russia, and for Siberia in particular, “green” architecture does sound new and fresh. Forced by the anxious reality, we are addressing this topic intentionally. The ecological crisis, growing energy prices, water, air and food deficits… Alexander Rappaport, our regular author, writes: “ It has been tolerable until a certain time, but under transition to the global civilization, as the nature is destroyed, and swellings of megapolises expand incredibly fast, the size and the significance of all these problems may grow a hundredfold”.However, for this very severe Siberian reality the newness of “green” architecture may turn out to be well-forgotten old. A traditional Siberian house used to be built on principles of saving and environmental friendliness– one could not survive in Siberia otherwise.Probably, in our turbulent times, it is high time to fasten “green belts”. But we should keep from enthusiastic sticking of popular green labels or repainting of signboards into green color. We should avoid being drowned in paper formalities under “green” slogans. And we should prevent the Earth from turning into the planet “Kin-dza-dza”.

  3. Sapwood area as an estimator of leaf area and foliar weight in cherrybark oak and green ash

    Science.gov (United States)

    James S. Meadows; John D. Hodges

    2002-01-01

    The relationships between foliar weight/leaf area and four stem dimensions (d.b.h., total stem cross-sectional area, total sapwood area, and current sapwood area at breast height) were investigated in two important bottomland tree species of the Southern United States, cherrybark oak (Quercus falcata var. pagodifolia ...

  4. Extension of a dynamic headspace multi-volatile method to milliliter injection volumes with full sample evaporation: Application to green tea.

    Science.gov (United States)

    Ochiai, Nobuo; Sasamoto, Kikuo; Tsunokawa, Jun; Hoffmann, Andreas; Okanoya, Kazunori; MacNamara, Kevin

    2015-11-20

    An extension of multi-volatile method (MVM) technology using the combination of a standard dynamic headspace (DHS) configuration, and a modified DHS configuration incorporating an additional vacuum module, was developed for milliliter injection volume of aqueous sample with full sample evaporation. A prior step involved investigation of water management by weighing of the water residue in the adsorbent trap. The extended MVM for 1 mL aqueous sample consists of five different DHS method parameter sets including choice of the replaceable adsorbent trap. An initial two DHS sampling sets at 25°C with the standard DHS configuration using a carbon-based adsorbent trap target very volatile solutes with high vapor pressure (>10 kPa) and volatile solutes with moderate vapor pressure (1-10 kPa). Subsequent three DHS sampling sets at 80°C with the modified DHS configuration using a Tenax TA trap target solutes with low vapor pressure (88%) for 17 test aroma compounds and moderate recoveries (44-71%) for 4 test compounds. The method showed good linearity (r(2)>0.9913) and high sensitivity (limit of detection: 0.1-0.5 ng mL(-1)) even with MS scan mode. The improved sensitivity of the method was demonstrated with analysis of a wide variety of aroma compounds in brewed green tea. Compared to the original 100 μL MVM procedure, this extension to 1 mL MVM allowed detection of nearly twice the number of aroma compounds, including 18 potent aroma compounds from top-note to base-note (e.g. 2,3-butanedione, coumarin, furaneol, guaiacol, cis-3-hexenol, linalool, maltol, methional, 3-methyl butanal, 2,3,5-trimethyl pyrazine, and vanillin). Sensitivity for 23 compounds improved by a factor of 3.4-15 under 1 mL MVM conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Sulfur volatiles in guava (Psidium guajava L.) leaves: possible defense mechanism.

    Science.gov (United States)

    Rouseff, Russell L; Onagbola, Ebenezer O; Smoot, John M; Stelinski, Lukasz L

    2008-10-08

    Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuwayama), which is the insect vector of Huanglongbing (HLB) or citrus greening disease. Seven sulfur volatiles were detected: hydrogen sulfide, sulfur dioxide, methanethiol, dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methional, and dimethyl trisulfide (DMTS). Identifications were based on matching linear retention index values on ZB-5, DB-Wax, and PLOT columns and MS spectra in the case of DMDS and DMS. DMDS is an insect toxic, defensive volatile produced only by wounded guava but not citrus leaves and, thus, may be the component responsible for the protective effect of guava against the HLB vector. DMDS is formed immediately after crushing, becoming the major headspace volatile within 10 min. Forty-seven additional leaf volatiles were identified from LRI and MS data in the crushed guava leaf headspace.

  6. Maple leaf (Acer sp.) extract mediated green process for the functionalization of ZnO powders with silver nanoparticles.

    Science.gov (United States)

    Vivekanandhan, Singaravelu; Schreiber, Makoto; Mason, Cynthia; Mohanty, Amar Kumar; Misra, Manjusri

    2014-01-01

    The functionalization of ZnO powders with silver nanoparticles (AgNPs) through a novel maple leaf extract mediated biological process was demonstrated. Maple leaf extract was found to be a very effective bioreduction agent for the reduction of silver ions. The reduction rate of Ag(+) into Ag(0) was found to be much faster than other previously reported bioreduction rates and was comparable to the reduction rates obtained through chemical means. The functionalization of ZnO particles with silver nanoparticles through maple leaf extract mediated bioreduction of silver was investigated through UV-visible spectrophotometry, transmission electron microscopy (TEM), and X-ray diffraction analysis. It was found that the ZnO particles were coated with silver nanoparticles 5-20 nm in diameter. The photocatalytic ability of the ZnO particles functionalized with silver nanoparticles was found to be significantly improved compared to the photocatalytic ability of the neat ZnO particles. The silver functionalized ZnO particles reached 90% degradation of the dye an hour before the neat ZnO particles. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Green synthesis of silver nanoparticles from aqueous leaf extract of Pomegranate (Punica granatum) and their anticancer activity on human cervical cancer cells

    Science.gov (United States)

    Sarkar, Sonia; Kotteeswaran, Venkatesan

    2018-06-01

    Plants contain different important phytochemicals that can be used as a potential treatment for various ailments including cancer. The green synthesis of silver nanoparticles from the extract of different plant parts has gained a wide range of engrossment among the researchers due to its unique optical and structural property. The aim of this study is green synthesis of silver nanoparticles from the aqueous leaf extract of pomegranate (Punica granatum) and to investigate its anticancer activity on human cervical cancer cells (HeLa). The synthesis of silver nanoparticle was depicted by the colour change from golden yellowish to dark brownish, UV-visible spectral analysis gave a characteristic surface plasmon absorption peak at . Further morphological characterization was done by Zeta potential where the size analysis was depicted to be 46.1 nm and zeta potential as . Fourier transform infrared spectroscopy (FTIR) inferred 3 intense sharp peaks at , , , confirmed the presence of flavonoids and polyphenols. The scanning electron microscopy (SEM) analysis with energy diffraction spectroscopy (EDS) confirmed the presence of silver nanoparticles with size ranged from to . X-ray diffraction (XRD) confirmed the crystallographic nature of silver. The cell proliferation activity of nanoparticles was tested by 3, ‑4, 5 dimethylthiazol-2,5 diphenyl tetrazolium bromide (MTT) assay where the inhibitory concentration () was found at inhibiting of HeLa cell line. The anticancer activity of nanoparticles was determined by lactate dehydrogenase (LDH) assay where showed of cytotoxicity. Furthermore, the anticancer property of nanoparticles was confirmed by the DNA fragmentation assay.

  8. STAY-GREEN and Chlorophyll Catabolic Enzymes Interact at Light-Harvesting Complex II for Chlorophyll Detoxification during Leaf Senescence in Arabidopsis[C][W

    Science.gov (United States)

    Sakuraba, Yasuhito; Schelbert, Silvia; Park, So-Yon; Han, Su-Hyun; Lee, Byoung-Doo; Andrès, Céline Besagni; Kessler, Felix; Hörtensteiner, Stefan; Paek, Nam-Chon

    2012-01-01

    During leaf senescence, plants degrade chlorophyll to colorless linear tetrapyrroles that are stored in the vacuole of senescing cells. The early steps of chlorophyll breakdown occur in plastids. To date, five chlorophyll catabolic enzymes (CCEs), NONYELLOW COLORING1 (NYC1), NYC1-LIKE, pheophytinase, pheophorbide a oxygenase (PAO), and red chlorophyll catabolite reductase, have been identified; these enzymes catalyze the stepwise degradation of chlorophyll to a fluorescent intermediate, pFCC, which is then exported from the plastid. In addition, STAY-GREEN (SGR), Mendel’s green cotyledon gene encoding a chloroplast protein, is required for the initiation of chlorophyll breakdown in plastids. Senescence-induced SGR binds to light-harvesting complex II (LHCII), but its exact role remains elusive. Here, we show that all five CCEs also specifically interact with LHCII. In addition, SGR and CCEs interact directly or indirectly with each other at LHCII, and SGR is essential for recruiting CCEs in senescing chloroplasts. PAO, which had been attributed to the inner envelope, is found to localize in the thylakoid membrane. These data indicate a predominant role for the SGR-CCE-LHCII protein interaction in the breakdown of LHCII-located chlorophyll, likely to allow metabolic channeling of phototoxic chlorophyll breakdown intermediates upstream of nontoxic pFCC. PMID:22366162

  9. Extraction and characterization of mixed phase KNO2-KNO3 nanocrystals derived from flat-leaf green spinach

    International Nuclear Information System (INIS)

    Hazarika, S; Mohanta, D

    2013-01-01

    Naturally available green spinach, which is a rich source of potassium, was used as the key ingredient to extract mixed-phase ferroelectric crystals of nitrite and nitrate derivatives (KNO 2 + KNO 3 ). The KNO 3 phase was found to be dominant for higher pH values, as revealed by the x-ray diffraction patterns. The characteristic optical absorption spectra exhibited intra-band π-π* electronic transitions, whereas Fourier transform infrared spectra exhibited characteristic N-O stretching vibrations. Differential scanning calorimetry revealed a broad endothermic peak at ∼121.8 °C, highlighting a transition from phase II to I via phase III of KNO 3 . Obtaining nanoscale ferroelectrics via the adoption of green synthesis is economically viable for large-scale production and possible application in ferroelectric elements/devices.

  10. RETRACTED: Green synthesis of zinc oxide nanoparticles using Moringa oleifera leaf extract and evaluation of its antimicrobial activity

    Science.gov (United States)

    Elumalai, K.; Velmurugan, S.; Ravi, S.; Kathiravan, V.; Ashokkumar, S.

    2015-05-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editor. The article contains the same image in two panels (Fig. 8A and B) which was previously published in "Facile, eco-friendly and template free photosynthesis of cauliflower like ZnO nanoparticles using leaf extract of Tamarindus indica (L.) and its biological evolution of antibacterial and antifungal activities" by K. Elumalai et al. in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 136 (2015) 1052-1057, http://dx.doi.org/10.1016/j.saa.2014.09.129 despite being attributed to different nanoparticles. Furthermore, Figures 9C, D and E are the same, despite being indicated as analysis of different microorganisms. The scientific community takes a very strong view on this scientific misbehavior and apologies are offered to readers of the journal that this was not detected during the submission process.

  11. Expanded separation technique for chlorophyll metabolites in Oriental tobacco leaf using non aqueous reversed phase chromatography.

    Science.gov (United States)

    Ishida, Naoyuki

    2011-08-26

    An improved separation method for chlorophyll metabolites in Oriental tobacco leaf was developed. While Oriental leaf still gives the green color even after the curing process, little attention has been paid to the detailed composition of the remaining green pigments. This study aimed to identify the green pigments using non aqueous reversed phase chromatography (NARPC). To this end, liquid chromatograph (LC) equipped with a photo diode array detector (DAD) and an atmospheric pressure chemical ionization/mass spectrometer (APCI/MSD) was selected, because it is useful for detecting low polar non-volatile compounds giving green color such as pheophytin a. Identification was based on the wavelength spectrum, mass spectrum and retention time, comparing the analytes in Oriental leaf with the commercially available and synthesized components. Consequently, several chlorophyll metabolites such as hydroxypheophytin a, solanesyl pheophorbide a and solanesyl hydroxypheophorbide a were newly identified, in addition to typical green pigments such as chlorophyll a and pheophytin a. Chlorophyll metabolites bound to solanesol were considered the tobacco specific components. NARPC expanded the number of detectable low polar chlorophyll metabolites in Oriental tobacco leaf. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Use of a plant-derived enzyme template for the production of the green-note volatile hexanal.

    Science.gov (United States)

    Schade, Frank; Thompson, John E; Legge, Raymond L

    2003-11-05

    Hexanal is a key organoleptic element of green-note that is found in both fragrances and flavors. We report a novel process for the production of hexanal using immobilized enzyme templates extracted from different plant sources in combination with hollow-fiber ultrafiltration for in situ separation. Enzyme templates, known to be responsible for the synthesis of hexanal from linoleic acid (18:2), were isolated from naturally enriched tissues including carnation petals, strawberry and tomato leaves. These templates were immobilized in an alginate matrix and used as a biocatalyst in a packed-bed bioreactor. Continuous product recovery was achieved using a hollow-fiber ultrafiltration unit. The effects of pH, reaction temperature, and substrate and enzyme concentrations were studied and their effects on hexanal generation identified and optimized. Utilizing optimized conditions, hexanal production 112-fold higher than endogenous steady-state levels in a corresponding amount of plant tissue could be achieved over a 30-minute period. Based on the reactor studies, product inhibition also appears to be an important factor for bioreactor-based hexanal production. Copyright 2003 Wiley Periodicals, Inc.

  13. Photo-induced green synthesis and antimicrobial efficacy of poly (ɛ-caprolactone)/curcumin/grape leaf extract-silver hybrid nanoparticles.

    Science.gov (United States)

    El-Sherbiny, Ibrahim M; El-Shibiny, Ayman; Salih, Ehab

    2016-07-01

    This study reports the photo-induced green synthesis and antimicrobial assessment of poly(ɛ-caprolactone)/curcumin/grape leaf extract-Ag hybrid nanoparticles (PCL/Cur/GLE-Ag NPs). PCL/Cur/GLE NPs were synthesized via emulsion-solvent evaporation in the presence of PVA as a capping agent, then used as active nano-supports for the green synthesis and stabilization of AgNPs on their surfaces. Both Cur and GLE were selected and incorporated into the PCL nano-supports due to their reported promising antimicrobial activity that would further enhance that of the synthesized AgNPs. The developed PCL/Cur/GLE NPs and PCL/Cur/GLE-Ag hybrid NPs were characterized using UV-visible spectrophotometry, high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). HRTEM images showed that the PCL/Cur/GLE NPs are monodispersed and spherical with size of about 270nm, and the AgNPs were formed mainly on their surfaces with average size in the range 10-30nm. The synthesized AgNPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220) and (311) planes. The antimicrobial characteristics of the newly developed NPs were investigated against gram-positive and gram-negative bacteria in addition to two fungal strains. The results demonstrated that the PCL/Cur/GLE-Ag hybrid NPs have a potential antimicrobial activity against pathogenic bacterial species and could be considered as an alternative antibacterial agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Green Synthesis of Silver Nanoparticles Using Polyalthia longifolia Leaf Extract along with D-Sorbitol: Study of Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    S. Kaviya

    2011-01-01

    Full Text Available Synthesis of silver nanoparticles (AgNPs using Polyalthia longifolia leaf extract as reducing and capping agent along with D-sorbitol used to increase the stability of the nanoparticles has been reported. The reaction is carried out at two different concentrations (10−3 M and 10−4 M of silver nitrate, and the effect of temperature on the synthesis of AgNPs is investigated by stirring at room temperature (25°C and at 60°C. The UV-visible spectra of NPs showed a blue shift with increasing temperature at both concentrations. FT-IR analysis shows that the biomoites played an important role in the reduction of Ag+ ions and the growth of AgNPs. TEM results were utilized for the determination of the size and morphology of nanoparticles. The synthesized silver nanoparticles are found to be highly toxic against Gram-positive bacteria than Gram-negative bacteria.

  15. Reactive trace gas emissions from stressed plants: a poorly characterized major source of atmospheric volatiles

    Science.gov (United States)

    Niinemets, Ülo

    2017-04-01

    Vegetation constitutes the greatest source of reactive volatile organic compounds in the atmosphere. The current emission estimates primarily rely on constitutive emissions that are present only in some plant species. However, all plant species can be induced to emit reactive volatiles by different abiotic and biotic stresses, but the stress-dependent emissions have been largely neglected in emission measurements and models. This presentation provides an overview of systematic screening of stress-dependent volatile emissions from a broad range of structurally and physiologically divergent plant species from temperate to tropical ecosystems. Ozone, heat, drought and wounding stress were the abiotic stresses considered in the screening, while biotic stress included herbivory, chemical elicitors simulating herbivory and fungal infections. The data suggest that any moderate to severe stress leads to significant emissions of a rich blend of volatiles, including methanol, green leaf volatiles (the lipoxygenase pathway volatiles, dominated by C6 aldehydes, alcohols and derivatives), different mono- and sesquiterpenes and benzenoids. The release of volatiles occurs in stress severity-dependent manner, although the emission responses are often non-linear with more severe stresses resulting in disproportionately greater emissions. Stress volatile release is induced in both non-constitutive and constitutive volatile emitters, whereas the rate of constitutive volatile emissions in constitutive emitters is often reduced under environmental and biotic stresses. Given that plants in natural conditions often experience stress, this analysis suggests that global volatile emissions have been significantly underestimated. Furthermore, in globally changing hotter climates, the frequency and severity of both abiotic and biotic stresses is expected to increase. Thus, the stress-induced volatile emissions are predicted to play a dominant role in plant-atmosphere interactions in near

  16. Nocturnal herbivore-induced plant volatiles attract the generalist predatory earwig Doru luteipes Scudder

    Science.gov (United States)

    Naranjo-Guevara, Natalia; Peñaflor, Maria Fernanda G. V.; Cabezas-Guerrero, Milton F.; Bento, José Maurício S.

    2017-10-01

    Numerous studies have demonstrated that entomophagous arthropods use herbivore-induced plant volatile (HIPV) blends to search for their prey or host. However, no study has yet focused on the response of nocturnal predators to volatile blends emitted by prey damaged plants. We investigated the olfactory behavioral responses of the night-active generalist predatory earwig Doru luteipes Scudder (Dermaptera: Forficulidae) to diurnal and nocturnal volatile blends emitted by maize plants ( Zea mays) attacked by either a stem borer ( Diatraea saccharalis) or a leaf-chewing caterpillar ( Spodoptera frugiperda), both suitable lepidopteran prey. Additionally, we examined whether the earwig preferred odors emitted from short- or long-term damaged maize. We first determined the earwig diel foraging rhythm and confirmed that D. luteipes is a nocturnal predator. Olfactometer assays showed that during the day, although the earwigs were walking actively, they did not discriminate the volatiles of undamaged maize plants from those of herbivore damaged maize plants. In contrast, at night, earwigs preferred volatiles emitted by maize plants attacked by D. saccharalis or S. frugiperda over undamaged plants and short- over long-term damaged maize. Our GC-MS analysis revealed that short-term damaged nocturnal plant volatile blends were comprised mainly of fatty acid derivatives (i.e., green leaf volatiles), while the long-term damaged plant volatile blend contained mostly terpenoids. We also observed distinct volatile blend composition emitted by maize damaged by the different caterpillars. Our results showed that D. luteipes innately uses nocturnal herbivore-induced plant volatiles to search for prey. Moreover, the attraction of the earwig to short-term damaged plants is likely mediated by fatty acid derivatives.

  17. Characterization, antibacterial, and neurotoxic effect of Green synthesized nanosilver using Ziziphus spina Christi aqueous leaf extract collected from Riyadh, Saudi Arabia

    Science.gov (United States)

    El-Ansary, Afaf; Warsy, Arjumand; Daghestani, Maha; Merghani, Nada M.; Al-Dbass, Abeer; Bukhari, Wadha; Al-Ojayan, Badryah; Ibrahim, Eiman M.; Al-Qahtani, Asma M.; Shafi Bhat, Ramesa

    2018-02-01

    The current study aims to synthesize silver nanoparticles using Ziziphus spina Christi (ZSC) or (Sidr) aqueous leaf extract collected from Riyadh, Saudi Arabia. The green synthesis of silver nanoparticles using sidr leaves extract was successful. Production of silver nanoparticles was confirmed through UV-vis Spectrophotometer, particles size and zeta potential analysis, Infra-red spectroscopy, Scanning, and Transmission Electron Microscope (SEM and TEM). The UV-visible spectra showed that the absorption peak existed at 400 nm. SEM analysis showed that the synthesized AgNPs were spherical but in slightly aggregated form. TEM demonstrated different size range of 4-33 nm with an average size of 13. The element analysis profile showed silver signal together with oxygen, calcium, and potassium peaks which might be related to the plant structure. Biological effects of the synthesized AgNPs exhibit satisfactory inhibitory effect against ten tested microorganisms. It inhibited the growth of 5 gram-positive and five gram-negative bacteria. Moreover, AgNPs demonstrated a synergistic effect on the neurotoxicity induced in rat pups with orally administered methyl mercury (MeHg). The present study showed that AgNPs prepared from ZSC might be a promising antimicrobial agent for successful treatment of bacterial infection in intensive care units (ICU) especially in case of antibiotic resistance.

  18. Green synthesis and characterization of gold and silver nanoparticles using Mussaenda glabrata leaf extract and their environmental applications to dye degradation.

    Science.gov (United States)

    Francis, Sijo; Joseph, Siby; Koshy, Ebey P; Mathew, Beena

    2017-07-01

    Plant-derived nanomaterials opened a green approach in solving the current environment issues. Present study focused on rapid microwave-assisted synthesis and applications of gold and silver nanoparticles mediated by aqueous leaf extract of Mussaenda glabrata. The synthesized nanoparticles were characterized by UV-vis, FT-IR, powder XRD, energy-dispersive X-ray spectroscopy (EDX), transmission electron (TEM), and atomic force microscopic techniques (AFM). FCC crystal structure of both nanoparticles was confirmed by peaks corresponding to (111), (200), (220), and (311) planes in XRD spectra and bright circular spots in SAED pattern. IC 50 values shown by gold and silver nanoparticles (44.1 ± 0.82 and 57.92 ± 1.33 μg/mL) reflected their high free radical scavenging potential. The synthesized gold and silver nanoparticles revealed their potency to inhibit pathogenic microorganisms Bacillus pumilus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Aspergillus niger, and Penicillium chrysogenum. Anthropogenic pollutants rhodamine B and methyl orange were effectively degraded from aquatic environment and waste water sewages of dye industries using the prepared nanocatalysts. The catalytic capacities of the synthesized nanoparticles were also exploited in the reduction of 4-nitrophenol. Graphical abstract.

  19. Structural characterization of mesoporous magnetite nanoparticles synthesized using the leaf extract of Calliandra haematocephala and their photocatalytic degradation of malachite green dye

    Science.gov (United States)

    Sirdeshpande, Karthikey Devadatta; Sridhar, Anushka; Cholkar, Kedar Mohan; Selvaraj, Raja

    2018-03-01

    A simple method for the synthesis of magnetite nanoparticles using the leaf extract of Calliandra haematocephala has been developed. UV-Vis spectrum showed a characteristic strong absorption band. SEM image revealed the bead-like spherical nanoparticles. EDS showed the prominent peaks for elemental iron and oxygen. PXRD patterns confirmed the crystalline nature and the average crystallite size of 7.45 nm. In addition, the lattice parameter value was calculated to be 8.413 Å, close to Fe3O4 nanoparticles. BET analysis disclosed the total specific surface area of the nanoparticles as 63.89 m2/g and the mesoporous structure of the nanoparticles with a pore radius of 34.18 Å. FTIR studies showed the specific bands at 599.82 and 472.53 cm-1, typical for Fe3O4 nanoparticles. The photocatalytic efficacy of the nanoparticles was demonstrated against the degradation of malachite green dye under sunlight irradiation and the photocatalytic degradation constant was calculated as 0.0621 min-1.

  20. Green synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract: study of antioxidant and anticancer activities

    Science.gov (United States)

    Nakkala, Jayachandra Reddy; Mata, Rani; Bhagat, Ekta; Sadras, Sudha Rani

    2015-03-01

    The present study reports the biological synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract and their in vitro free radical scavenging efficacy as well as antiproliferative effect in Hep2 cells. The formation of silver (GYAgNPs) and gold nanoparticles (GYAuNPs) was confirmed by UV-visible spectroscopy. The average size of synthesized GYAgNPs and GYAuNPs was found to be 33 and 26 nm, respectively, by DLS particle size analyzer. TEM analysis indicated spherical shape of GYAgNPs and GYAuNPs and in EDX analysis they produced strong signal for silver and gold, respectively. Both GYAgNPs and GYAuNPs exhibited strong in vitro free radical quenching ability and their activity was comparable to that of GYLE. The cytotoxic effect of GYAgNPs and GYAuNPs in Hep2 cells was examined by MTT assay in which GYAgNPs displayed an IC50 value of 121 µg ml-1, while GYAuNPs produced up to 38 % of inhibition at the maximum concentration of 250 µg ml-1 used in this study. Distinct morphological changes were observed in Hep2 cells following treatment with GYAgNPs and GYAuNPs at 24 h, and orange-colored apoptotic bodies were located by acridine orange and ethidium bromide double-staining technique. Also, there was increase in the levels of reactive oxygen species in treated cells as indicated by 2',7'-dichlorofluorescin diacetate staining. Further, nuclear changes like chromatin condensation/fragmentation were also observed by propidium iodide and 4',6-diamidino-2-phenylindole dilactate staining methods. These findings support that the antiproliferative effects of GYAgNPs and GYAuNPs in Hep2 cells are mediated through induction of apoptosis.

  1. Green synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract: study of antioxidant and anticancer activities

    Energy Technology Data Exchange (ETDEWEB)

    Nakkala, Jayachandra Reddy; Mata, Rani; Bhagat, Ekta; Sadras, Sudha Rani, E-mail: dr.ssrlab@gmail.com, E-mail: sadrassudha@gmail.com [Pondicherry University, Department of Biochemistry and Molecular Biology, School of Life Sciences (India)

    2015-03-15

    The present study reports the biological synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract and their in vitro free radical scavenging efficacy as well as antiproliferative effect in Hep2 cells. The formation of silver (GYAgNPs) and gold nanoparticles (GYAuNPs) was confirmed by UV–visible spectroscopy. The average size of synthesized GYAgNPs and GYAuNPs was found to be 33 and 26 nm, respectively, by DLS particle size analyzer. TEM analysis indicated spherical shape of GYAgNPs and GYAuNPs and in EDX analysis they produced strong signal for silver and gold, respectively. Both GYAgNPs and GYAuNPs exhibited strong in vitro free radical quenching ability and their activity was comparable to that of GYLE. The cytotoxic effect of GYAgNPs and GYAuNPs in Hep2 cells was examined by MTT assay in which GYAgNPs displayed an IC{sub 50} value of 121 µg ml{sup −1}, while GYAuNPs produced up to 38 % of inhibition at the maximum concentration of 250 µg ml{sup −1} used in this study. Distinct morphological changes were observed in Hep2 cells following treatment with GYAgNPs and GYAuNPs at 24 h, and orange-colored apoptotic bodies were located by acridine orange and ethidium bromide double-staining technique. Also, there was increase in the levels of reactive oxygen species in treated cells as indicated by 2′,7′-dichlorofluorescin diacetate staining. Further, nuclear changes like chromatin condensation/fragmentation were also observed by propidium iodide and 4′,6-diamidino-2-phenylindole dilactate staining methods. These findings support that the antiproliferative effects of GYAgNPs and GYAuNPs in Hep2 cells are mediated through induction of apoptosis.

  2. Green synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract: study of antioxidant and anticancer activities

    International Nuclear Information System (INIS)

    Nakkala, Jayachandra Reddy; Mata, Rani; Bhagat, Ekta; Sadras, Sudha Rani

    2015-01-01

    The present study reports the biological synthesis of silver and gold nanoparticles from Gymnema sylvestre leaf extract and their in vitro free radical scavenging efficacy as well as antiproliferative effect in Hep2 cells. The formation of silver (GYAgNPs) and gold nanoparticles (GYAuNPs) was confirmed by UV–visible spectroscopy. The average size of synthesized GYAgNPs and GYAuNPs was found to be 33 and 26 nm, respectively, by DLS particle size analyzer. TEM analysis indicated spherical shape of GYAgNPs and GYAuNPs and in EDX analysis they produced strong signal for silver and gold, respectively. Both GYAgNPs and GYAuNPs exhibited strong in vitro free radical quenching ability and their activity was comparable to that of GYLE. The cytotoxic effect of GYAgNPs and GYAuNPs in Hep2 cells was examined by MTT assay in which GYAgNPs displayed an IC 50 value of 121 µg ml −1 , while GYAuNPs produced up to 38 % of inhibition at the maximum concentration of 250 µg ml −1 used in this study. Distinct morphological changes were observed in Hep2 cells following treatment with GYAgNPs and GYAuNPs at 24 h, and orange-colored apoptotic bodies were located by acridine orange and ethidium bromide double-staining technique. Also, there was increase in the levels of reactive oxygen species in treated cells as indicated by 2′,7′-dichlorofluorescin diacetate staining. Further, nuclear changes like chromatin condensation/fragmentation were also observed by propidium iodide and 4′,6-diamidino-2-phenylindole dilactate staining methods. These findings support that the antiproliferative effects of GYAgNPs and GYAuNPs in Hep2 cells are mediated through induction of apoptosis

  3. Ultrasound assisted green synthesis of cerium oxide nanoparticles using Prosopis juliflora leaf extract and their structural, optical and antibacterial properties

    Directory of Open Access Journals (Sweden)

    Arunachalam Thirunavukkarasu

    2018-03-01

    Full Text Available Cerium oxide nanoparticles (CONPs were prepared using ultrasound assisted leaf extract of Prosopis juliflora acting as a reducing as well as stabilizing agent. The synthesized CONPs were characterized by ultraviolet-visible absorption spectroscopy (UV-Vis, particle size analyzer (PSA, Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS and high-resolution transmission electron microscopy (HRTEM. From the UV-Vis analysis, the optical band gap of the prepared CONPs (Eg = 3.62 eV was slightly increased as compared to the bulk ceria (Eg = 3.19 eV. The phytochemicals in the extract reduced the particle size to 3.7 nm ± 0.3 nm, as it is evident from the PSA. FT-IR results confirmed the Ce-O stretching bands by showing the peaks at 452 cm-1. The Raman spectrumshowed a characteristic peak shift for CONPs at 461.2 cm-1. XRD analysis revealed the cubic fluorite structure of the synthesizednanoparticles with the lattice constant, a of 5.415 Å and unit cell volume, V of 158.813 Å3. XPS signals were used to determine the concentration of Ce3+ and Ce4+ in the prepared CONPs and it was found that major amount of cerium exist in the Ce4+ state. HRTEM images showed spherical shaped particles with an average size of 15 nm. Furthermore, the antibacterial activity of the prepared CONPs was evaluated and their efficacies were compared with the conventional antibiotics using disc diffusion assay against a set of Gram positive (G+ bacteria (Staphylococcus aureus, Streptococcus pneumonia and Gram negative (G- bacteria (Pseudomonas aeruginosa, Proteus vulgaris. The results suggested that CONPs showed antibacterial activity with significant variations due to the differences in the membrane structure and cell wall composition among the two groups tested.

  4. The Use of Green Leaf Membranes to Promote Appetite Control, Suppress Hedonic Hunger and Loose Body Weight.

    Science.gov (United States)

    Erlanson-Albertsson, Charlotte; Albertsson, Per-Åke

    2015-09-01

    On-going research aims at answering the question, which satiety signal is the most potent or which combination of satiety signals is the most potent to stop eating. There is also an aim at finding certain food items or food additives that could be used to specifically reduce food intake therapeutically. Therapeutic attempts to normalize body weight and glycaemia with single agents alone have generally been disappointing. The success of bariatric surgery illustrates the rationale of using several hormones to treat obesity and type-2-diabetes. We have found that certain components from green leaves, the thylakoids, when given orally have a similar rationale in inducing the release of several gut hormones at the same time. In this way satiety is promoted and hunger suppressed, leading to loss of body weight and body fat. The mechanism is a reduced rate of intestinal lipid hydrolysis, allowing the lipolytic products to reach the distal intestine and release satiety hormones. The thylakoids also regulate glucose uptake in the intestine and influences microbiota composition in the intestine in a prebiotic direction. Using thylakoids is a novel strategy for treatment and prevention of obesity.

  5. Photosynthetic Properties and Potentials for Improvement of Photosynthesis in Pale Green Leaf Rice under High Light Conditions

    Directory of Open Access Journals (Sweden)

    Junfei Gu

    2017-06-01

    Full Text Available Light is the driving force of plant growth, providing the energy required for photosynthesis. However, photosynthesis is also vulnerable to light-induced damage caused by the production of reactive oxygen species (ROS. Plants have therefore evolved various protective mechanisms such as non-photochemical quenching (NPQ to dissipate excessively absorbed solar energy as heat; however, photoinhibition and NPQ represent a significant loss in solar energy and photosynthetic efficiency, which lowers the yield potential in crops. To estimate light capture and light energy conversion in rice, a genotype with pale green leaves (pgl and a normally pigmented control (Z802 were subjected to high (HL and low light (LL. Chlorophyll content, light absorption, chloroplast micrographs, abundance of light-harvesting complex (LHC binding proteins, electron transport rates (ETR, photochemical and non-photochemical quenching, and generation of ROS were subsequently examined. Pgl had a smaller size of light-harvesting chlorophyll antenna and absorbed less photons than Z802. NPQ and the generation of ROS were also low, while photosystem II efficiency and ETR were high, resulting in improved photosynthesis and less photoinhibition in pgl than Z802. Chlorophyll synthesis and solar conversion efficiency were higher in pgl under HL compared to LL treatment, while Z802 showed an opposite trend due to the high level of photoinhibition under HL. In Z802, excessive absorption of solar energy not only increased the generation of ROS and NPQ, but also exacerbated the effects of increases in temperature, causing midday depression in photosynthesis. These results suggest that photosynthesis and yield potential in rice could be enhanced by truncated light-harvesting chlorophyll antenna size.

  6. Photosynthetic Properties and Potentials for Improvement of Photosynthesis in Pale Green Leaf Rice under High Light Conditions

    Science.gov (United States)

    Gu, Junfei; Zhou, Zhenxiang; Li, Zhikang; Chen, Ying; Wang, Zhiqin; Zhang, Hao; Yang, Jianchang

    2017-01-01

    Light is the driving force of plant growth, providing the energy required for photosynthesis. However, photosynthesis is also vulnerable to light-induced damage caused by the production of reactive oxygen species (ROS). Plants have therefore evolved various protective mechanisms such as non-photochemical quenching (NPQ) to dissipate excessively absorbed solar energy as heat; however, photoinhibition and NPQ represent a significant loss in solar energy and photosynthetic efficiency, which lowers the yield potential in crops. To estimate light capture and light energy conversion in rice, a genotype with pale green leaves (pgl) and a normally pigmented control (Z802) were subjected to high (HL) and low light (LL). Chlorophyll content, light absorption, chloroplast micrographs, abundance of light-harvesting complex (LHC) binding proteins, electron transport rates (ETR), photochemical and non-photochemical quenching, and generation of ROS were subsequently examined. Pgl had a smaller size of light-harvesting chlorophyll antenna and absorbed less photons than Z802. NPQ and the generation of ROS were also low, while photosystem II efficiency and ETR were high, resulting in improved photosynthesis and less photoinhibition in pgl than Z802. Chlorophyll synthesis and solar conversion efficiency were higher in pgl under HL compared to LL treatment, while Z802 showed an opposite trend due to the high level of photoinhibition under HL. In Z802, excessive absorption of solar energy not only increased the generation of ROS and NPQ, but also exacerbated the effects of increases in temperature, causing midday depression in photosynthesis. These results suggest that photosynthesis and yield potential in rice could be enhanced by truncated light-harvesting chlorophyll antenna size. PMID:28676818

  7. Light Quality Dependent Changes in Morphology, Antioxidant Capacity, and Volatile Production in Sweet Basil (Ocimum basilicum).

    Science.gov (United States)

    Carvalho, Sofia D; Schwieterman, Michael L; Abrahan, Carolina E; Colquhoun, Thomas A; Folta, Kevin M

    2016-01-01

    Narrow-bandwidth light treatments may be used to manipulate plant growth, development and metabolism. In this report LED-based light treatments were used to affect yield and metabolic content of sweet basil (Ocimum basilicum L. cv "Ceasar") grown in controlled environments. This culinary herb produces an aroma highly appreciated by consumers, primarily composed of terpenes/terpenoids, phenylpropanoids, and fatty-acid- derived volatile molecules. Basil plants were grown under narrow-bandwidth light conditions, and leaf area, height, mass, antioxidant capacity and volatile emissions were measured at various time points. The results indicate reproducible significant differences in specific volatiles, and in biochemical classes of volatiles, compared to greenhouse grown plants. For example, basil plants grown under blue/red/yellow or blue/red/green wavelengths emit higher levels of a subset of monoterpenoid volatiles, while a blue/red/far-red treatment leads to higher levels of most sesquiterpenoid volatile molecules. Specific light treatments increase volatile content, mass, and antioxidant capacity. The results show that narrow-bandwidth illumination can induce discrete suites of volatile classes that affect sensory quality in commercial herbs, and may be a useful tool in improving commercial production.

  8. Antimicrobial activities of tapioca starch/decolorized hsian-tsao leaf gum coatings containing green tea extracts in fruit-based salads, romaine hearts and pork slices.

    Science.gov (United States)

    Chiu, Po-En; Lai, Lih-Shiuh

    2010-04-30

    The antimicrobial activities of edible coatings based on a tapioca starch/decolorized hsian-tsao leaf gum (dHG) matrix with various green tea extracts (GTEs) were evaluated. Its effect on the shelf-life extension of fruit-based salads, romaine hearts, and pork slices were investigated as well. Three types of GTEs from hot water (80 degrees C) (W), 40% (E4) and 80% (E8) ethanol were prepared. It was found that all GTEs showed pronounced inhibition on Gram positive bacteria in agar media, including Staphylococcus aureus BCRC 10781, Bacillus cereus BCRC 11778 and Listeria monocytogenes BCRC 14848, but not on Gram negative bacteria, such as Escherichia coli DH10beta and Salmonella enteria BCRC 10747. The antimicrobial activities increased with increasing GTEs concentration (1, 2 and 5%), but did not differentiate significantly in terms of the effect of extraction solvents. When various GTEs (1%) were added to an edible coating formulation based on 1.35% tapioca starch +0.15% dHG +0.225% glycerol, pronounced antimicrobial activity on Gram positive bacteria was also observed as evaluated by using cylinder diffusion and antimicrobial migration tests. It was believed that the active compounds in green tea extracts could leave the coating matrix and migrate to increase the non-growth area. When being sprayed on various real food models, all tapioca starch/dHG coatings containing GTEs could successfully reduce the aerobic counting and growth of yeasts/molds by 1 to 2 log cycles in fruit-based salads, as compared to the control sample. Furthermore, during refrigerated storage of romaine hearts and pork slices for 48h, tapioca starch/dHG coatings with E4 extracts demonstrated pronounced antimicrobial activity against Gram positive bacteria (4-6 log cycles reduction), followed by W extracts and E8 extracts in a decreasing order. Such results implied the high efficacy of antimicrobial migration of tapioca starch/dHG coatings containing GTEs and their application potentials on

  9. De novo biosynthesis of volatiles induced by insect herbivory in cotton plants

    International Nuclear Information System (INIS)

    Pare, P.W.; Tumlinson, J.H.

    1997-01-01

    In response to insect feeding on the leaves, cotton (Gossypium hirsutum L.) plants release elevated levels of volatiles, which can serve as a chemical signal that attracts natural enemies of the herbivore to the damaged plant. Pulse-labeling experiments with [13C]CO2 demonstrated that many of the volatiles released, including the acyclic terpenes (E,E)-alpha-farnesene, (E)-beta-farnesene, (E)-beta-ocimene, linalool,(E)-4,8-dimethyl-1,3,7-nonatriene, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetrane, as well as the shikimate pathway product indole, are biosynthesized de novo following insect damage. However, other volatile constituents, including several cyclic terpenes, butyrates, and green leaf volatiles of the lipoxygenase pathway are released from storage or synthesized from stored intermediates. Analysis of volatiles from artificially damaged plants, with and without beet armyworm (Spodoptera exigua Hubner) oral secretions exogenously applied to the leaves, as well as volatiles from beet armyworm-damaged and -undamaged control plants, demonstrated that the application of caterpillar oral secretions increased both the production and release of several volatiles that are synthesized de novo in response to insect feeding. These results establish that the plant plays an active and dynamic role in mediating the interaction between herbivores and natural enemies of herbivores

  10. Microwave Accelerated Green Synthesis of Stable Silver Nanoparticles with Eucalyptus globulus Leaf Extract and Their Antibacterial and Antibiofilm Activity on Clinical Isolates.

    Directory of Open Access Journals (Sweden)

    Khursheed Ali

    Full Text Available A simple and rapid microwave assisted method of green synthesis of silver nanoparticles (AgNPs was developed using aqueous leaf extract of Eucalyptus globulus(ELE, and their antibacterial and antibiofilm potential investigated. With this aim, the aqueous solutions of ELE and AgNO3(1 mM were mixed (1:4 v/v, and microwave irradiated at 2450 Mhz, for 30 sec. The instant color change of the ELE-AgNO3 mixture from pale yellow to dark brown indicated ELE-AgNPs synthesis. The intensity of peak at 428 nm in UV-Vis spectra, due to the surface plasmon resonance of AgNPs, varied with the amount of ELE, AgNO3 concentration, pH and time of incubation. The biosynthesized ELE-AgNPs were characterized by UV-visible spectroscopy, XRD, TEM, SEM-EDX, FTIR and TGA analyses. The size of ELE-AgNPs was determined to be in range of 1.9-4.3 nm and 5-25 nm, with and without microwave treatment, respectively. SEM exhibited the capping of AgNPs with the ELE constituents, and validated by FTIR analysis. The FTIR data revealed the presence of plant organic constituents and metabolites bound to ELE-AgNPs, which contributes for their stability. The antimicrobial activity of ELE-AgNPs was assessed by growth and biofilm inhibition of extended spectrum β-lactamase (ESBL producing Pseudomonas aeruginosa, Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA and methicillin-sensitive Staphylococcus aureus (MSSA clinical bacterial isolates. The results demonstrated that S. aureus were more sensitive to ELE-AgNPs than E. coli and P. aeruginosa. MRSA exhibited higher sensitive than MSSA, whereas P. aeruginosa were more sensitive than E. coli to ELE-AgNPs treatment. Also, significant (83 ± 3% and 84 ± 5% biofilm inhibition was observed in case of S. aureus and P. aeruginosa, respectively. The results elucidated environmentally friendly, economical and quick method for production of colloidal bio-functionalized ELE-AgNPs, for effectual clinical applications, as broad

  11. Leaf ontogeny dominates the seasonal exchange of volatile organic compounds (VOC) in a SRC-poplar plantation during an entire growing season

    Science.gov (United States)

    Brilli, Federico; Gioli, Beniamino; Fares, Silvano; Zenone, Terenzio; Zona, Donatella; Gielen, Bert; Loreto, Francesco; Janssens, Ivan; Ceulemans, Reinhart

    2015-04-01

    The declining cost of many renewable energy technologies and changes in the prices of fossil fuels have recently encouraged governments policies to subsidize the use of biomass as a sustainable source of energy. Deciduous poplars (Populus spp.) trees are often selected for biomass production in short rotation coppiced (SRC) for their high CO2 photosynthetic assimilation rates and their capacity to develop dense canopies with high values of leaf area index (LAI). So far, observations and projections of seasonal variations of many VOC fluxes has been limited to strong isoprenoids emitting evergreen ecosystems such tropical and Mediterranean forests as well as Citrus and oil palm plantation, all having constant values of LAI. We run a long-term field campaign where the exchange of VOC, together with CO2 and water vapor was monitored during an entire growing season (June - November, 2012) above a SRC-based poplar plantation. Our results confirmed that isoprene and methanol were the most abundant fluxes emitted, accounting for more than 90% of the total carbon released in form of VOC. However, Northern climates characterized by fresh summertime temperatures and recurring precipitations favored poplar growth while inhibiting the development of isoprene emission that resulted in only 0.7% of the net ecosystem carbon exchange (NEE). Besides, measurements of a multitude of VOC fluxes by PTR-TOF-MS showed bi-directional exchange of oxygenated-VOC (OVOC) such as: formaldehyde, acetaldehyde, acetone, isoprene oxidation products (iox, namely MVK, MAC and MEK) as well as ethanol and formic acid. The application of Self Organizing Maps to visualize the relationship between the full time-series of many VOC fluxes and the observed seasonal variations of environmental, physiological and structural parameters proved the most abundant isoprene ad methanol fluxes to occur mainly on the hottest days under mid-high light intensities when also NEE and evapotraspiration reached the highest

  12. Phytoseiulus persimilis response to herbivore-induced plant volatiles as a function of mite-days.

    Science.gov (United States)

    Nachappa, Punya; Margolies, David C; Nechols, James R; Loughin, Thomas

    2006-01-01

    The predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae), uses plant volatiles (i.e., airborne chemicals) triggered by feeding of their herbivorous prey, Tetranychus urticae (Acari: Tetranychidae), to help locate prey patches. The olfactory response of P. persimilis to prey-infested plants varies in direct relation to the population growth pattern of T. urticae on the plant; P. persimilis responds to plants until the spider mite population feeding on a plant collapses, after which infested plants do not attract predators. It has been suggested that this represents an early enemy-free period for T. urticae before the next generation of females is produced. We hypothesize that the mechanism behind the diminished response of predators is due to extensive leaf damage caused by T. urticae feeding, which reduces the production of volatiles irrespective of the collapse of T. urticae population on the plant. To test this hypothesis we investigated how the response of P. persimilis to prey-infested plants is affected by: 1) initial density of T. urticae, 2) duration of infestation, and 3) corresponding leaf damage due to T. urticae feeding. Specifically, we assessed the response of P. persimilis to plants infested with two T. urticae densities (20 or 40 per plant) after 2, 4, 6, 8, 10, 12 or 14 days. We also measured leaf damage on these plants. We found that predator response to T. urticae-infested plants can be quantified as a function of mite-days, which is a cumulative measure of the standing adult female mite population sampled and summed over time. That is, response to volatiles increased with increasing numbers of T. urticae per plant or with the length of time plant was infested by T. urticae, at least as long at the leaves were green. Predatory mites were significantly attracted to plants that were infested for 2 days with only 20 spider mites. This suggests that the enemy-free period might only provide a limited window of opportunity for T. urticae

  13. The effect of green tea extract on the removal of sulfur-containing oral malodor volatiles in vitro and its potential application in chewing gum.

    Science.gov (United States)

    Zeng, Q C; Wu, A Z; Pika, J

    2010-09-01

    Increasing pH solution from 7.5 to 8.0 was found to significantly improve the effectiveness of green tea extract for methanethiol removal in vitro. Green tea extract was also found to remove hydrogen sulfide and its effectiveness was greatly improved under alkaline conditions. It was found that with green tea extract, maximum H₂S removal was achieved when the pH was between 8.1 and 8.4 at 37 °C for 5 min. Further increases in pH resulted in decrease of the extract effectiveness. Vegetable acetone powders which contain polyphenol oxidases or peroxidases were found to further enhance the effectiveness for the removal of thiols when used in combination with green tea extracts at body temperature under alkaline conditions. Adding 5% baking soda to green tea extract-containing chewing gum was found to buffer saliva pHs to 8.0 during 10 min of chewing. However, severe discoloration was observed and undesirable bitterness was perceived, most likely due to the polymerization of unencapsulated green tea polyphenols. Therefore, encapsulation of green tea extract is recommended for applications at elevated pHs.

  14. Mechanism of monoterpene volatilization in Salvia mellifera

    Energy Technology Data Exchange (ETDEWEB)

    Dement, W A; Tyson, B J; Mooney, H A

    1975-01-01

    Monoterpene volatilization in Salvia mellifera is primarily dependent on the vapor pressures of the terpenes as they are influenced by temperature, the humidity of the air surrounding the leaf and the surface area of oil present on the leaf. 12 references, 1 figure, 2 tables.

  15. "Supermarket Column Chromatography of Leaf Pigments" Revisited: Simple and Ecofriendly Separation of Plant Carotenoids, Chlorophylls, and Flavonoids from Green and Red Leaves

    Science.gov (United States)

    Dias, Alice M.; Ferreira, Maria La Salete

    2015-01-01

    A simple and ecofriendly procedure was developed in order to prepare extracts from red and green leaves. This procedure enables the separation of yellow, green, and red band pigments and optimizes the previously reported baking soda "supermarket column". The same extract also led to a novel and colorful potato starch column, which can…

  16. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  17. The effect of ultraviolet-B radiation on gene expression and pigment composition in etiolated and green pea leaf tissue: UV-B-induced changes are gene-specific and dependent upon the developmental stage

    International Nuclear Information System (INIS)

    Jordan, B.R.; James, P.E.; Strid, A.; Anthony, R.G.

    1994-01-01

    The effect of ultraviolet-B radiation (UV-B: 280–320nm) on gene expression and pigment composition has been investigated in pea tissue at different stages of development. Pea (Pisum sativum L., cv. Feltham First) seedlings were grown for 17d and then exposed to supplementary UV-B radiation. Chlorophyll a per unit fresh weight decreased by more than 20% compared with control levels after exposure to UV-B radiation for 7d. In contrast, chlorophyll b content remained the same or increased slightly. Leaf protein biosynthesis, as determined by 35 S-methionine incorporation, was rapidly inhibited by UV-B radiation, although the steady-state levels of proteins were either unchanged or only slightly altered. RNA transcripts for the chlorophyll a/b binding protein (cab) were also rapidly reduced to low or even undetectable levels in the expanded third leaf or younger leaf bud tissue after exposure to UV-B radiation. In contrast, cab RNA transcripts were either low or undetectable in etiolated pea tissue, but increased substantially in light and during exposure to UV-B radiation. The cab RNA transcripts were still present at control levels in pea plants after 7d of greening under supplementary UV-B radiation or UV-B alone. The protein composition changed significantly over the 7d of greening, but no differences could be detected between the light treatments. The increase in chlorophyll content was slightly greater during de-etiolation under supplementary UV-B radiation than under control irradiance. Under UV-B radiation alone, chlorophyll was synthesized at a greatly reduced rate. Changes in protective pigments were also determined. Anthocyanins did not change in either etiolated or green tissue exposed to UV-B radiation. However, other flavonoids increased substantially in either tissue during exposure to light and UV-B radiation. The RNA levels for chalcone synthase were measured in green and etiolated tissue exposed to UV-B radiation. The chs RNA transcripts were

  18. Comparison of volatile and polyphenolic compounds in Brazilian green propolis and its botanical origin Baccharis dracunculifolia Comparação de volatilidade e compostos polifenólicos na própolis verde brasileira e sua origem botânica Baccharis dracunculifolia

    Directory of Open Access Journals (Sweden)

    Mário Roberto Maróstica Junior

    2008-03-01

    Full Text Available Ethanolic extracts and essential oils from Green Propolis from southeastern Brazil and leaf buds from its botanical origin Baccharis dracunculifolia were analyzed by Reversed Phase High Performance Liquid Chromatography (RP-HPLC, Reversed Phase High Performance Thin Layer Chromatography (RP-HPTLC and Gas Chromatography - Mass Spectrometry (GC-MS. The essential oils were obtained by hydro-distillation. Both ethanolic extracts and essential oils showed similar chromatographic profiles. Thirteen flavonoids were identified by RP-HPLC and RP-HPTLC analyses in both samples. Twenty-three volatile compounds were identified by GC-MS analyses. Seventeen were present in both essential oils. The major flavonoid compound in both extracts was artepillin C. The major volatile compound in both essential oils was nerolidol. The major compounds identified in this work could be used as chemical markers in order to classify and identify botanical origins of propolis.Extratos etanólicos e óleos essenciais de própolis verde do sudeste brasileiro e gemas de sua origem botânica (Baccharis dracunculifolia foram analisados por CLAE-FR (Cromatografia Líquida de Alta Eficiência em Fase Reversa, CCDAE (Cromatografia em Camada Delgada de Alta Eficiência e CG-EM (Cromatografia Gasosa acoplada a Espectrometria de Massas. Os óleos essenciais foram obtidos por hidro destilação. Extratos etanólicos e óleos essenciais de Baccharis dracunculifolia e de própolis mostraram perfis cromatográficos similares entre si. Treze flavonóides foram identificados por CLAE-FR e CCDAE em ambas as amostras. Vinte e três compostos voláteis foram identificados por CG EM, sendo dezessete deles presentes em ambos os óleos essenciais. Artepillin C foi o flavonóide encontrado em maiores concentrações em ambas as amostras, enquanto nerolidol foi o volátil majoritário em ambos os óleos essenciais. Os compostos majoritários identificados neste trabalho podem ser utilizados como

  19. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  20. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  1. Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions

    Directory of Open Access Journals (Sweden)

    Choong-Min Ryu

    2013-05-01

    Full Text Available Systemic acquired resistance (SAR is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields.

  2. Green synthesis of silver nanoparticles using Sida acuta (Malvaceae) leaf extract against Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Rajeswary, Mohan

    2013-12-01

    Mosquitoes act as a vector for most of the life-threatening diseases like malaria, yellow fever, dengue fever, chikungunya fever, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management, emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain, and adverse effects on environmental quality and nontarget organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are nontoxic, easily available at affordable prices, biodegradable, and show broad-spectrum target-specific activities against different species of vector mosquitoes. In the present study, the larvicidal activity of silver nanoparticles (AgNPs) synthesized using Sida acuta plant leaf extract against late third instar larvae of Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti was determined. Range of concentrations of synthesized AgNPs (10, 20, 30, 40, and 50 μg/mL) and aqueous leaf extract (50, 100, 150, 200, and 250 μg/mL) were tested against the larvae of C. quinquefasciatus, A. stephensi and A. aegypti. The synthesized AgNPs from S. acuta leaf were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis. Larvae were exposed to varying concentrations of aqueous crude extract and synthesized AgNPs for 24 h. Considerable mortality was evident after the treatment of S. acuta for all three important vector mosquitoes. The LC50 and LC90 values of S. acuta aqueous leaf extract appeared to be most effective

  3. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  4. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  5. Quantitative patterns between plant volatile emissions induced by biotic stresses and the degree of damage

    Directory of Open Access Journals (Sweden)

    Ülo eNiinemets

    2013-07-01

    Full Text Available Plants have to cope with a plethora of biotic stresses such as herbivory and pathogen attacks throughout their life cycle. The biotic stresses typically trigger rapid emissions of volatile products of lipoxygenase pathway (LOX products, various C6 aldehydes, alcohols and derivatives, also called green leaf volatiles associated with oxidative burst. Further a variety of defense pathways is activated, leading to induction of synthesis and emission of a complex blend of volatiles, often including methyl salicylate, indole, mono-, homo- and sesquiterpenes. The airborne volatiles are involved in systemic responses leading to elicitation of emissions from non-damaged plant parts. For several abiotic stresses, it has been demonstrated that volatile emissions are quantitatively related to the stress dose. The biotic impacts under natural conditions vary in severity from mild to severe, but it is unclear whether volatile emissions also scale with the severity of biotic stresses in a dose-dependent manner. Furthermore, biotic impacts are typically recurrent, but it is poorly understood how direct stress-triggered and systemic emission responses are silenced during periods intervening sequential stress events. Here we review the information on induced emissions elicited in response to biotic attacks, and argue that biotic stress severity vs. emission rate relationships should follow principally the same dose-response relationships as previously demonstrated for several abiotic stresses. Analysis of several case studies investigating the elicitation of emissions in response to chewing herbivores, aphids, rust fungi, powdery mildew and Botrytis, suggests that induced emissions do respond to stress severity in dose-dependent manner. Bi-phasic emission kinetics of several induced volatiles have been demonstrated in these experiments, suggesting that next to immediate stress-triggered emissions, biotic stress elicited emissions typically have a secondary

  6. THE EFFECT OF GREEN TEA LEAF EXTRACT ON SPATIAL MEMORY FUNCTION AND SUPEROXYDE DISMUTASE ENZYME ACTIVITY IN MICE WITH D-GALACTOSE INDUCED DIMENTIA

    Directory of Open Access Journals (Sweden)

    Ainun Rahmasari Gumay

    2017-04-01

    Full Text Available Background: Oxidative stress and inflammation play an important role in pathogenesis of brain aging and neurodegenerative diseases such as Alzheimer. Green tea has been shown to have antioxidant, anti-inflammatory, anticancer, and neuroprotective activity. Objectives: to determine the effect of green tea extract on spatial memory function and superoxide dismutase enzyme activity in mice with D-galactose induced dementia Methods: An experimental study using "post test only control group design". Twenty male BALB/c Mice aged 6-8 weeks were divided into 4 groups. Negative control group (NG was induced by subcutaneous injection of D-galactose (150 mg/kg BW once daily for 6 weeks. GT-90, GT-270, GT-540 were induced by D-galactose and orally administered with 90, 270, and 540 mg/kg BW of green tea extract once daily for 6 weeks. The spatial memory functions were assessed using Morris water maze and SOD enzyme activities were evaluated using ELISA. One-way Anova and Kruskal-Wallis were used for statistical analysis.  Results: mean percentage of latency time in the GT-90 (35.29 (SD= 2.69%, GT-270 (35.28 (SD= 2.62%, and GT-540 (35.62 (SD=5.05% were significantly higher compared to that of NG (20.38 (SD = 3.21%, p <0.05. SOD enzyme activity in the GT-270 (0.78 (SD = 0.07 U/ml was significantly higher compared to that of NG (0.51 (SD = 0.01 U ml, p= 0.004. Conclusion: Green tea extract may improve spatial memory function and the activity of superoxide dismutase enzyme in mice with D-galactose induced dementia.

  7. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  8. Viewpoint – Water Variability, Soil Nutrient Heterogeneity and Market Volatility – Why Sub-Saharan Africa’s Green Revolution Will Be Location-Specific and Knowledge-Intensive

    Directory of Open Access Journals (Sweden)

    Pieter van der Zaag

    2010-02-01

    Full Text Available In his interesting Viewpoint article in Water Alternatives, Bruce Lankford suggests that an African Green Revolution cannot come about without irrigation. But he does not convincingly explain why irrigated areas expand only very slowly. This viewpoint article argues that grain yields have remained stagnant in Africa because of high temporal rainfall variability, significant spatial soil nutrient heterogeneity, and weak and volatile markets. This combination calls for location-specific interventions that are aimed at enhancing farmers’ capacity to buffer water variations and address nutrient deficits. This finding is consistent with what Lankford dismisses as an "atomised" approach, but which would preferably be called a farmer-centred approach. Thus a massive investment in African agriculture is indeed required, primarily focused on the creation of knowledge that does justice to the local variation in water and nutrient availability. It should aim to empower farmers to experiment and be innovative, and remake agricultural extension and agricultural engineering exciting with cutting-edge disciplines. Irrigation may then emerge as the right thing to do.

  9. Volatiles released from Vaccinium corymbosum were attractive to Aegorhinus superciliosus (Coleoptera: Curculionidae) in an olfactometric bioassay.

    Science.gov (United States)

    Parra, Leonardo; Mutis, Ana; Ceballos, Ricardo; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

    2009-06-01

    The objective of this study was to evaluate the role of host volatiles in the relationship between a blueberry plant Vaccinium corymbosum L. and the raspberry weevil Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), the principal pest of blueberry in the south of Chile. Volatiles from the aerial part of different phenological stages of the host were collected on Porapak Q and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Several chemical groups were identified including green leaf volatiles, aromatic compounds, and terpenes. The olfactometric responses of A. superciliosus toward different odor sources were studied in a four-arm olfactometer. Blueberry shoots at the phenological stages of fruit set, and blue-pink fruit color elicited the greatest behavioral responses from weevils. Five compounds (2-nonanone, eucalyptol, R- and S-limonene, and 4-ethyl benzaldehyde) elicited an attractant behavioral response from A. superciliosus. The results suggest the host location behavior of A. superciliosus could be mediated by volatiles derived from V. corymbosum. This work has identified a number of compounds with which it is possible to develop a lure for the principal pest of blueberry in southern Chile.

  10. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  11. Low-cost and eco-friendly green synthesis of silver nanoparticles using Prunus japonica (Rosaceae) leaf extract and their antibacterial, antioxidant properties.

    Science.gov (United States)

    Saravanakumar, Arthanari; Peng, Mei Mei; Ganesh, Mani; Jayaprakash, Jayabalan; Mohankumar, Murugan; Jang, Hyun Tae

    2017-09-01

    Low cost and eco-friendly green synthesis of silver nanoparticles (AgNPs) from silver nitrate (AgNO 3 ) using Prunus japonica leaves extract as reducing agent by a simple method at room temperature. The biosynthesized nanoparticles (NPs) were characterized by UV-Vis, tunneling electron microscopy (HR-TEM), scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectrophotometer (EDAX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). In UV-Vis spectroscopy results, the λ max was observed at 441 nm. The AgNPs synthesized were spherical, hexagonal, and irregular in shapes. The EDAX and XRD spectrum confirmed the presence of silver ions and crystalline nature of synthesized AgNPs. FTIR showed the functional groups such as C = O, N-H and C-N groups involved in the reduction of Ag +  to Ag. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was performed and it showed the percentage inhibition in concentration-dependent manner. The synthesized AgNPs showed antibacterial activity against Escherichia coli, Proteus vulgaris, Staphylococcus aureus and Bacillus cereus to different extents and the higher activity was observed in Proteus vulgaris.

  12. Green synthesis of NiO nanoparticles using Aegle marmelos leaf extract for the evaluation of in-vitro cytotoxicity, antibacterial and photocatalytic properties.

    Science.gov (United States)

    Angel Ezhilarasi, A; Judith Vijaya, J; Kaviyarasu, K; John Kennedy, L; Ramalingam, R Jothi; Al-Lohedan, Hamad A

    2018-03-01

    In the present study, we report the green synthesis of NiO nanoparticles using Aegle marmelos as a fuel and this method is ecofriendly and cost effective. The plant Aegle marmelos is used in the field of pharmaceuticals to cure diseases like chronic diarrhea, peptic ulcers and dysentery in India for nearly 5 centuries. The as-prepared nanoparticles were confirmed as pure face centered cubic phase and single crystalline in nature by XRD. The formation of agglomerated spherical nanoparticles was shown by HR-SEM and HR-TEM images. The particle size calculated from HR-SEM was in the range 8-10 nm and it matches with the average crystallite size calculated from the XRD pattern. NiO shows intense emission peaks at 363 and 412 nm in its PL spectra. The band gap of 3.5 eV is observed from DRS studies and the formation of pure NiO is confirmed by FT-IR spectra. The as-prepared NiO nanoparticles show super paramagnetic behavior, when magnetization studies are carried out. It is then evaluated for cytotoxic activity towards A549 cell culture, antibacterial activity and photocatalytic degradation (PCD) of 4‑chlorophenol (4‑CP), which is known as the endocrine disrupting chemical (EDC). From the results, it is found that the cell viability of A549 cells was effectively reduced and it showed better antibacterial activity towards gram positive bacterial strains. It is also proved to be an efficient and stable photocatalyst towards the degradation of 4‑CP. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated,

  14. Green engineered biomolecule-capped silver and copper nanohybrids using Prosopis cineraria leaf extract: Enhanced antibacterial activity against microbial pathogens of public health relevance and cytotoxicity on human breast cancer cells (MCF-7).

    Science.gov (United States)

    Jinu, U; Gomathi, M; Saiqa, I; Geetha, N; Benelli, G; Venkatachalam, P

    2017-04-01

    This research focused on green engineering and characterization of silver (PcAgNPs) and copper nanoparticles (PcCuNPs) using Prosopis cineraria (Pc) leaf extract prepared by using microwave irradiation. We studied their enhanced antimicrobial activity on human pathogens as well as cytotoxicity on breast cancer cells (MCF-7). Biofabricated silver and copper nanoparticles exhibited UV-Visible absorbance peaks at 420 nm and 575 nm, confirming the bioreduction and stabilization of nanoparticles. Nanoparticles were characterized by FTIR, XRD, FESEM, and EDX analysis. FTIR results indicated the presence of alcohols, alkanes, aromatics, phenols, ethers, benzene, amines and amides that were possibly involved in the reduction and capping of silver and copper ions. XRD analysis was performed to confirm the crystalline nature of the silver and copper nanoparticles. FESEM analysis suggested that the nanoparticles were hexagonal or spherical in shape with size ranging from 20 to 44.49 nm and 18.9-32.09 nm for AgNPs and CuNPs, respectively. EDX analysis confirmed the presence of silver and copper elemental signals in the nanoparticles. The bioengineered silver and copper nanohybrids showed enhanced antimicrobial activity against Gram-positive and Gram-negative MDR human pathogens. MTT assay results indicated that CuNPs show potential cytotoxic effect followed by AgNPs against MCF-7 cancer cell line. IC 50 were 65.27 μg/ml, 37.02 μg/ml and 197.3 μg/ml for PcAgNPs, PcCuNPs and P. cineraria leaf extracts, respectively, treated MCF-7 cells. The present investigation highlighted an effective protocol for microwave-assisted synthesis of biomolecule-loaded silver and copper nanoparticles with enhanced antibacterial and anticancer activity. Results strongly suggested that bioengineered AgNPs and CuNPs could be used as potential tools against microbial pathogens and cancer cells. Copyright © 2017 Elsevier Ltd. 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. 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.

  17. Presidential Green Chemistry Challenge: 2005 Designing Greener Chemicals Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2005 award winner, Archer Daniels Midland, developed Archer RC, a nonvolatile, biobased, reactive coalescent that replaces volatile organic coalescents in architectural latex paints.

  18. 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.

  19. Metaphysical green

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    to adapt to urban environment. It explores the potential of Sensation of Green in the city. The paper questions whether the Sensation of Green could introduce a new spectrum of greens, beside the real green. It develops the term of metaphysical green – does green have to be green or can it be only...

  20. Quantification of leaf greenness and leaf spectral profile in plant diagnosis using an optical scanner Quantificação do nível de verde e padrão espectral foliar no diagnóstico de plantas através de um scanner ótico

    Directory of Open Access Journals (Sweden)

    Ryoichi Doi

    2012-06-01

    Full Text Available Observation of leaf spectral profile (color enables suitable management measures to be taken for crop production. An optical scanner was used: 1 to obtain an equation to determine the greenness of plant leaves and 2 to examine the power to discriminate among plants grown under different nutritional conditions. Sweet basil seedlings grown on vermiculite were supplemented with one-fifth-strength Hoagland solutions containing 0, 0.2, 1, 5, 20, and 50 mM NH4+. The 5 mM treatment resulted in the greatest leaf and shoot weights, indicating a quadratic growth response pattern to the NH4+ gradient. An equation involving b*, black and green to describe the greenness of leaves was provided by the spectral profiling of a color scale for rice leaves as the standard. The color scale values for the basil leaves subjected to 0.2 and 1 mM NH4+ treatments were 1.00 and 1.12, respectively. The other treatments resulted in significantly greater values of 2.25 to 2.42, again indicating a quadratic response pattern. Based on the spectral data set consisting of variables of red-green-blue and other color models and color scale values, in discriminant analysis, 81% of the plants were correctly classified into the six NH4+ treatment groups. Combining the spectral data set with the growth data set consisting of leaf and shoot weights, 92% of the plant samples were correctly classified whereas, using the growth data set, only 53% of plants were correctly classified. Therefore, the optical scanning of leaves and the use of spectral profiles helped plant diagnosis when biomass measurements were not effective.A observação do perfil espectral da folha (cor permite medidas de gestão adequadas a serem consideradas na produção. Um scanner óptico foi usado para: 1 obter uma equação para determinar o verde das folhas e 2 examinar o poder de discriminar entre as plantas cultivadas sob diferentes condições nutricionais. Mudas de manjericão cultivadas em vermiculita foram

  1. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  2. Green(ing) infrastructure

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2014-03-01

    Full Text Available the generation of electricity from renewable sources such as wind, water and solar. Grey infrastructure – In the context of storm water management, grey infrastructure can be thought of as the hard, engineered systems to capture and convey runoff..., pumps, and treatment plants.  Green infrastructure reduces energy demand by reducing the need to collect and transport storm water to a suitable discharge location. In addition, green infrastructure such as green roofs, street trees and increased...

  3. 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.

  4. 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.

  5. The Effects of a Plant Growth Regulator, Leaf Removal, Bagging, and Harvest Time on the Lipoxygenase Activity and Fatty Acid Composition of Pinot Noir Grapevines

    International Nuclear Information System (INIS)

    Ju, Y.; Zeng, J.; Zhu, M.; Lv, X.; Wang, T.; Zhang, Z.; Li, H.; Fang, Y.

    2016-01-01

    Green leaf volatiles (GLVs) are an important source of grape aromas, and lipoxygenase is a key enzyme involved in the formation of green leaf volatile substances. In addition, fatty acids are the main substrates that compose GLVs and are the main precursor compound utilized in the formation of grape aromas, which are an important index of grape quality. We examined the effects of a plant growth regulator, leaf removal, bagging, and harvest time on the lipoxygenase (LOX) activity, and the fatty acid composition of grapevines were studied. The following four experimental treatments were conducted using Pinot Noir (Vitis vinifera L.) grapevines to study the following variables: treatment with a plant growth regulator, leaf removal, fruit bagging, and harvest time. We obtained the following results. (1) 16 types of fatty acids were detected in the grape skins. The unsaturated fatty acid content consisted mainly of linoleic acid, oleic acid and palmitoleic acid; however, no linolenic acid was detected. In addition, the saturated fatty acid content consisted primarily of palmitic acid, stearic acid, behenic acid and arachidic acid. (2) Abscisic acid (ABA), methyl jasmonate (MeJA), light intensity, and harvest time appeared to effect LOX activity. (3) According to a principal component analysis (PCA) of the four treatments and the fatty acid content of the skins, ABA (concentration of 1000 mg/L), MeJA (concentrations of 100 meu mol/L, 400 meu mol/L and 800 meu mol/L) and early harvest treatment were responsible for the changes in fatty acid content. These results could be helpful in vineyard management and in improving the quality of grapes. (author)

  6. Green Jobs in Tennessee: Economic Impact of Green Investments

    OpenAIRE

    Murat Arik

    2011-01-01

    The term green jobs has been widely used to describe jobs in businesses that are particularly related to renewable energy, energy efficiency, or environmental sustainability. The Business and Economic Research Center has partnered with the Tennessee Department of Labor and Workforce Development to estimate the economic impact of six ground-breaking green investments in Tennessee: Hemlock Semiconductor, Wacker Chemie AG, Volkswagen, Nissan Leaf and Storage Battery Manufacturing, Tennessee Sola...

  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. Volatile components of vine leaves from two Portuguese grape varieties (Vitis vinifera L.), Touriga Nacional and Tinta Roriz, analysed by solid-phase microextraction.

    Science.gov (United States)

    Fernandes, Bruno; Correia, Ana C; Cosme, Fernanda; Nunes, Fernando M; Jordão, António M

    2015-01-01

    The purpose of this work was to study the volatile composition of vine leaves and vine leaf infusion prepared from vine leaves collected at 30 and 60 days after grape harvest of two Vitis vinifera L. species. Eighteen volatile compounds were identified by gas chromatography-mass spectrometry in vine leaves and in vine leaf infusions. It was observed that the volatile compounds present in vine leaves are dependent on the time of harvest, with benzaldehyde being the major volatile present in vine leaves collected at 30 days after harvesting. There are significant differences in the volatile composition of the leaves from the two grape cultivars, especially in the sample collected at 60 days after grape harvest. This is not reflected in the volatile composition of the vine leaf infusion made from this two cultivars, the more important being the harvesting date for the volatile profile of vine leaf infusion than the vine leaves grape cultivar.

  9. Towards green loyalty: the influences of green perceived risk, green image, green trust and green satisfaction

    Science.gov (United States)

    Chrisjatmiko, K.

    2018-01-01

    The paper aims to present a comprehensive framework for the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty. The paper also seeks to account explicitly for the differences in green perceived risk, green image, green trust, green satisfaction and green loyalty found among green products customers. Data were obtained from 155 green products customers. Structural equation modeling was used in order to test the proposed hypotheses. The findings show that green image, green trust and green satisfaction has positive effects to green loyalty. But green perceived risk has negative effects to green image, green trust and green satisfaction. However, green perceived risk, green image, green trust and green satisfaction also seems to be a good device to gain green products customers from competitors. The contributions of the paper are, firstly, a more complete framework of the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty analyses simultaneously. Secondly, the study allows a direct comparison of the difference in green perceived risk, green image, green trust, green satisfaction and green loyalty between green products customers.

  10. 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.

  11. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Boyce, J. W.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Magna, T.; Ni, P.; Tartese, R.; hide

    2017-01-01

    The chapter will begin with an introduction that defines magmatic volatiles (e.g., H, F, Cl, S) versus geochemical volatiles (e.g., K, Rb, Zn). We will discuss our approach of understanding both types of volatiles in lunar samples and lay the ground work for how we will determine the overall volatile budget of the Moon. We will then discuss the importance of endogenous volatiles in shaping the "Newer Views of the Moon", specifically how endogenous volatiles feed forward into processes such as the origin of the Moon, magmatic differentiation, volcanism, and secondary processes during surface and crustal interactions. After the introduction, we will include a re-view/synthesis on the current state of 1) apatite compositions (volatile abundances and isotopic compositions); 2) nominally anhydrous mineral phases (moderately to highly volatile); 3) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar pyroclastic glass beads; 4) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar basalts; 5) volatile (moderately to highly volatile) abundances in and isotopic compositions of melt inclusions; and finally 6) experimental constraints on mineral-melt partitioning of moderately to highly volatile elements under lunar conditions. We anticipate that each section will summarize results since 2007 and focus on new results published since the 2015 Am Min review paper on lunar volatiles [9]. The next section will discuss how to use sample abundances of volatiles to understand the source region and potential caveats in estimating source abundances of volatiles. The following section will include our best estimates of volatile abundances and isotopic compositions (where permitted by available data) for each volatile element of interest in a number of important lunar reservoirs, including the crust, mantle, KREEP, and bulk Moon. The final section of the chapter will focus upon future work, outstanding questions

  12. Study of nutritional value of dried tea leaves and infusions of black, green and white teas from Chinese plantations

    Science.gov (United States)

    Czernicka, Maria; Zaguła, Grzegorz; Bajcar, Marcin; Saletnik, Bogdan; Puchalski, Czesław

    The processing of tea leaves determines the contents of bioactive ingredients, hence it should be expected that each variety of tea, black, red or green, will represent a different package of compounds of physiological importance. Taste and aroma, as well as price and brand are the main factors impacting consumers’ preferences with regard to tea of their choice; on the other hand consumers less frequently pay attention to the chemical composition and nutritional value of tea. The purpose of the study was assessment of the nutritional value of black, green and white high-quality tea leaf from Chinese plantations based on the chemical composition of the dried leaves as well as minerals and caffeine content in tea infusions. The research material included 18 high-quality loose-leaf teas produced at Chinese plantations, imported to Poland, and purchased in an online store. The analyses included examination of the dried tea leaves for their chemical composition (contents of water, protein, volatile substances and ash) and assessment of selected minerals and caffeine contents in the tea infusions. High-quality Chinese green teas were found with the most valuable composition of minerals, i.e. the highest contents of Zn, Mn, Mg, K, Ca and Al and the highest contents of protein in comparison to the other products. Chinese black teas had the highest contents of total ash and caffeine and white teas were characterized with high content of volatile substances, similar to the black teas, and the highest content of water and the lowest content of total ash. The three types of tea brews examined in the present study, in particular green tea beverages, significantly enhance the organism’s mineral balance by providing valuable elements

  13. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  14. The influence of low dose irradiation on volatile constituents of Imperial and Ellendale mandarins

    International Nuclear Information System (INIS)

    Wood, A.F.; Mitchell, G.E.; McLauchlan, R.L.; Hammerton, K.

    1992-01-01

    Volatile compounds were collected from Imperial (Citrus reticulata) and Ellendale (Citrus reticulata/Citrus sinensis hybrid) mandarins, green and degreened, irradiated at 0, 75, and 300 Gy. Thirty-three individual volatile components were isolated, limonene being the major volatile. Irradiation caused only minor changes in the concentrations of some volatiles and the changes were of no value as indicators of irradiation treatment. 18 refs., 3 tabs. 2 figs

  15. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Anand, M.; Boyce, J. W.; Burney, D.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Klima, R. L.; Magna, T.; Ni, P.; Steenstra, E.; Tartèse, R.; Vander Kaaden, K. E.

    2018-04-01

    This abstract discusses numerous outstanding questions on the topic of endogenous lunar volatiles that will need to be addressed in the coming years. Although substantial insights into endogenous lunar volatiles have been gained, more work remains.

  16. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  17. Normalization for Implied Volatility

    OpenAIRE

    Fukasawa, Masaaki

    2010-01-01

    We study specific nonlinear transformations of the Black-Scholes implied volatility to show remarkable properties of the volatility surface. Model-free bounds on the implied volatility skew are given. Pricing formulas for the European options which are written in terms of the implied volatility are given. In particular, we prove elegant formulas for the fair strikes of the variance swap and the gamma swap.

  18. 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.

  19. Green technology meets ecotoxicology

    Directory of Open Access Journals (Sweden)

    Kristina Radošević

    2016-01-01

    Full Text Available By applying concept and principles of green chemistry into different technological processes, green technologies are developed. The environmental and economic benefits of “green” approach is achieved through several directions, such as the use of renewable raw materials, creation of economic efficiency, the use of alternative reaction conditions, as well as the application of non-conventional solvents. From the point view of green chemistry, alternative solvents, in order to be a “green“ substitution to hazardous organic solvents, should be: non-volatile, non-flammable, stabile, synthesized by an environmentally friendly procedure, nontoxic and biodegradable. The toxic impact of all newly synthesized chemicals, such as alternative solvents, could be determined by methods and techniques of ecotoxicology. Ecotoxicology, an interdisciplinary scientific field, can serve as a way of monitoring the greenness of the processes. In vivo and in vitro experiments are used to study the effects of chemicals on different levels of organizations, from molecules to communities and ecosystem. The usage of in vitro methods is encouraged by a scientific community and regulatory agencies as an alternative to in vivo studies in order to reduce the number of laboratory animals used in the toxicological studies. Therefore, in this paper we gave a brief overview on the usage of animal cell cultures within the field of green chemistry and technology.

  20. Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2013-01-01

    textabstractIn this paper we document that realized variation measures constructed from highfrequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive.

  1. 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.

  2. Green Tourism

    OpenAIRE

    Hasan, Ali

    2014-01-01

    Green tourism is defined as environmentally friendly tourism activities with various focuses and meanings. In a broad term, green tourism is about being an environmentally friendly tourist or providing environmentally friendly tourist services. The green tourism concept would be highly appealing to tourism enterprises and operators owing to increasing governmental pressure to improve environmental performance by adopting effective and tangible environmental management techniques. Green to...

  3. Metaphysical green

    OpenAIRE

    Earon, Ofri

    2011-01-01

    “Sensation of Green is about the mental process like touching, seeing, hearing, or smelling, resulting from the immediate stimulation of landscape forms, plants, trees, wind and water. Sensation of Green triggers a feeling of scale, cheerfulness, calmness and peace. The spatial performance of Sensation of Green is created by a physical interaction between the language of space and the language of nature” The notion of Sensation of Green was developed through a previous study ‘Learning from th...

  4. Metaphysical green

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    example is a tiny Danish summer house from 1918 . The second example is ‘House before House’ , in Tokyo. The third example is a prefabricated house ‘CHU’ . The analysis evaluates the characteristics of diverse tones of green – from green image to green sensation. The analysis is based on the original...... of Sensation of Green is created by a physical interaction between the language of space and the language of nature” The notion of Sensation of Green was developed through a previous study ‘Learning from the Summer House’ investigating the unique architectural characteristics of the Danish summer houses...... the Sensation of Green? Three existing examples are agents to this discussion. The first example is a Danish summer house. The other two are international urban examples. While the summer house articulates the original meaning of Sensation of Green, the urban examples illustrate its urban context. The first...

  5. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  6. Three odorant binding proteins may regulate the behavioural response of Chrysopa pallens to plant volatiles and the aphid alarm pheromone (E)-β-farnesene.

    Science.gov (United States)

    Li, Z-Q; Zhang, S; Cai, X-M; Luo, J-Y; Dong, S-L; Cui, J-J; Chen, Z-M

    2017-06-01

    Artificial Chrysopa pallens release is a well-known method for suppressing aphids, but it is difficult to establish lacewing populations in the field. Understanding the functions of C. pallens odorant-binding proteins (CpalOBPs) and behavioural responses of C. pallens to plant volatiles and aphid alarm pheromone (E)-ß-farnesene has important implications for population establishment after lacewing release. Based on our previous study, five antennae-enriched CpalOBPs were selected. Sequence alignment and phylogenetic analysis revealed that these five CpalOBPs were Classic OBPs and separated into different clades. Of them, CpalOBP10 clustered in the same clade with aphid OBP7, which mediates the perception of green leaf volatiles and (E)-ß-farnesene. Ligand-binding assays showed 31 compounds, including plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene, had high binding affinities for at least one of these five CpalOBPs. Of the 31 compounds, the pest-induced volatiles (Z)-3-hexenyl hexanoate and 2-hexyl-1-decanol, used in host location by the black bean aphid, elicited significant attractive behavioural responses from C. pallens. Conversely, (E)-ß-farnesene elicited strongly repellent behavioural responses. It is conceivable that C. pallens utilizes plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene as foraging cues. Our studies provide new insights into the interrelationships amongst C. pallens, its prey and the host plants. Compounds that elicited significant behavioural responses from C. pallens were also identified. © 2017 The Royal Entomological Society.

  7. Bidirectional exchange of biogenic volatiles with vegetation: emission sources, reactions, breakdown and deposition

    Science.gov (United States)

    Niinemets, Ülo; Fares, Silvano; Harley, Peter; Jardine, Kolby J.

    2014-01-01

    Biogenic volatile organic compound (BVOC) emissions are widely modeled as inputs to atmospheric chemistry simulations. However, BVOC may interact with cellular structures and neighboring leaves in a complex manner during volatile diffusion from the sites of release to leaf boundary layer and during turbulent transport to the atmospheric boundary layer. Furthermore, recent observations demonstrate that the BVOC emissions are bidirectional, and uptake and deposition of BVOC and their oxidation products are the rule rather than the exception. This review summarizes current knowledge of within-leaf reactions of synthesized volatiles with reactive oxygen species (ROS), uptake, deposition and storage of volatiles and their oxidation products as driven by adsorption on leaf surface and solubilization and enzymatic detoxification inside leaves. The available evidence indicates that due to reactions with ROS and enzymatic metabolism, the BVOC gross production rates are much larger than previously thought. The degree to which volatiles react within leaves and can be potentially taken up by vegetation depends on compound reactivity, physicochemical characteristics, as well as their participation in leaf metabolism. We argue that future models should be based on the concept of bidirectional BVOC exchange and consider modification of BVOC sink/source strengths by within-leaf metabolism and storage. PMID:24635661

  8. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  9. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  10. Asymmetric Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2014-01-01

    markdownabstract__Abstract__ In this paper we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized

  11. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  12. Green roofs

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-04-01

    Full Text Available , beetles and spiders); and the number of birds that nest in vegetated roofs (including kestrels, swallows, and wagtails). Objective The primary objective of a green roof is to create a living habitat in an otherwise barren environment, hence the use... the negative environmental impacts including plant and insect specie loss. Thus at a philosophical level green roofs support the notion “replace what you displace”. Key ecological issues that can be addressed through green roofs include: Negative effects...

  13. The volatility of HOL

    International Nuclear Information System (INIS)

    Wren, D.J.; Sanipelli, G.

    1985-01-01

    The volatility of HOI has been measured using a mass spectrometer to analyze the gas phase above an aqueous solution. The HOI in solution was generated continuously in a flow reactor that combined I/sup -/ and OCl/sup -/ solutions. The analysis has resulted in a lower limit of 6X10/sup 3/ mol . dm/sup -3/ . atm/sup -1/ for the equilibrium constant for the reaction HOI(g)/equilibrium/HOI(aq). This value is a factor 30 greater than the best previous estimate. This new limit for HOI volatility results in higher total iodine partition coefficients, particularly for solutions with pH>8. The upper limit for the equilibrium constant is consistent with essentially zero volatility for HOI. The effect of HOI volatility on total iodine volatility is briefly discussed as a function of solution chemistry and kinetics

  14. Green thunderstorms

    Science.gov (United States)

    Gallagher, Frank Woolsey, III

    Many people around the world have observed green light apparently emanating from severe thunderstorms, but until recently there has been no scientific study of the phenomenon. Green thunderstorms have been observed from time to time in association with deep convection or severe weather events. Some skeptics who have not personally observed a green thunderstorm suggest that they are some kind of illusion. The existence of green thunderstorms has been objectively demonstrated by recording spectra of light from thunderstorms using a handheld spectrophotometer. During the spring and summer of 1995 and the spring of 1996 numerous storms were observed and spectra of the light emanating from these storms were recorded. Observations were made both at the ground and aboard research aircraft. Furthermore, time series of spectra were recorded as the observed color of some storms changed from dark blue to a bluish-green. Several hypotheses have been advanced to explain the occurrence of green light in connection with severe storms. Fankhauser gave some observational support to the belief that green light from thunderstorms is possible and believed that the source of the light is from the blue sky penetrating thin regions in the clouds. Fraser believes that light from the setting sun, in combination with the process of scattering by atmospheric molecules, creates the green light associated with severe weather and the thunderstorm acts only as a black backdrop. Unfortunately, no cloud illuminated by the sun is black and the green airlight produced by the Fraser theory is in reality overwhelmed by light reflected by the cloud. Often the unusual coloration has been attributed to hail or to reflection of light from foliage on the ground. The quantitative measurements made during the observation period fail to support these assumptions. We have observed thunderstorms to be green over ground that was not green and we have observed blue thunderstorms over ground that was green

  15. Interior Volatile Reservoirs in Mercury

    Science.gov (United States)

    Anzures, B. A.; Parman, S. W.; Milliken, R. E.; Head, J. W.

    2018-05-01

    More measurements of 1) surface volatiles, and 2) pyroclastic deposits paired with experimental volatile analyses in silicate minerals can constrain conditions of melting and subsequent eruption on Mercury.

  16. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  17. Behaviorally Green

    DEFF Research Database (Denmark)

    Sunstein, Cass; Reisch, Lucia A.

    2016-01-01

    of suggestion, inertia, and loss aversion. If well-chosen, green defaults are likely to have large effects in reducing the economic and environmental harms associated with various products and activities. Such defaults may or may not be more expensive to consumers. In deciding whether to establish green...

  18. Green Tea

    Science.gov (United States)

    ... and cancer. Green tea is consumed as a beverage. It is also sold in liquid extracts, capsules, and tablets and is sometimes used in topical products (intended to be applied to the skin). How Much Do We Know? Although many studies have been done on green tea and its ...

  19. Modelling Volatility Spillovers for Bio-ethanol, Sugarcane and Corn

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); Y-A. Wang (Yu-Ann)

    2016-01-01

    textabstractThe recent and rapidly growing interest in biofuel as a green energy source has raised concerns about its impact on the prices, returns and volatility of related agricultural commodities. Analyzing the spillover effects on agricultural commodities and biofuel helps commodity suppliers

  20. Green consumerism

    DEFF Research Database (Denmark)

    de Groot, Judith I.M.; Schuitema, Geertje; Garson, Carrie Lee

    and biospheric values influence the importance of such ‘green’ product characteristics on purchasing intentions. In two within-subjects full-factorial experimental studies (N = 100 and N = 107), we found that purchase intentions of products were only steered by green characteristics if prices were low...... and the brand was familiar. Green product characteristics did not influence purchase intentions at all when these proself product characteristics were not fulfilled (i.e., high prices and unfamiliar brands). The importance of proself and green product characteristics on purchasing intentions was also......Our presentation will focus on the influence of product characteristics and values on green consumerism. Although generally a majority of consumers support the idea of purchasing green products, we argue, based on social dilemma theory, that proself product characteristics and egoistic...

  1. Green lights

    DEFF Research Database (Denmark)

    Fisker, Peter Kielberg

    This study investigates the effect of drought on economic activity globally using remote sensing data. In particular, predicted variation in greenness is correlated with changes in the density of artificial light observed at night on a grid of 0.25 degree latitude-longitude pixels. I define drought...... as greenness estimated by lagged variation in monthly rainfall and temperature. This definition of drought performs well in identifying self-reported drought events since 2000 compared with measures of drought that do not take greenness into account, and the subsequent analysis indicates that predicted...... variation in greenness is positively associated with year-on-year changes in luminosity: If a unit of observation experiences a predicted variation in greenness that lies 1 standard deviation below the global mean, on average 1.5 - 2.5 light pixels out of 900 are extinguished that year. Finally, an attempt...

  2. Pluto's Volatile Transport

    Science.gov (United States)

    Young, Leslie

    2012-10-01

    Pluto's varying subsolar latitude and heliocentric distance leads to large variations in the surface volatile distribution and surface pressure. I present results of new volatile transport models (Young 2012a, b). The models include insolation, thermal emission, subsurface conduction, heating of a volatile slab, internal heat flux, latent heat of sublimation, and strict global mass balance. Numeric advances include initial conditions that allow for rapid convergence, efficient computation with matrix arithmetic, and stable Crank-Nicholson timesteps for both bare and volatile-covered areas. Runs of the model show six distinct seasons on Pluto. (1) As Pluto approaches perihelion, the volatiles on the old winter pole (the Rotational North Pole, RNP) becomes more directly illuminated , and the pressure and albedo rise rapidly. (2) When a new ice cap forms on the Rotational South Pole, RSP, volatiles are exchanged between poles. The pressure and albedo change more slowly. (3) When all volatiles have sublimed from the RNP, the albedo and pressure drop rapidly. (4-6) A similar pattern is repeated near aphelion with a reversal of the roles and the poles. I will compare results with earlier Pluto models of Hansen and Paige (1996), show the dependence on parameters such as substrate inertia, and make predictions for the New Horizons flyby of Pluto in 2015. This work was supported, in part, by funding from NASA Planetary Atmospheres Grant NNG06GF32G and the Spitzer project (JPL research support Agreement 1368573). Hansen, C. J. and D. A. Paige 1996. Seasonal Nitrogen Cycles on Pluto. Icarus 120, 247-265. Young, L. A. 2012a. Volatile transport on inhomogeneous surfaces: I - Analytic expressions, with application to Pluto’s day. Icarus, in press Young, L. A. 2012b. Volatile transport on inhomogeneous surfaces: II. Numerical calculations, with application to Pluto's season. In preparation.

  3. 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.

  4. 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.

  5. 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.

  6. (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 ...

  7. Comparison of leaf color chart observations with digital photographs and spectral measurements for estimating maize leaf chlorophyll content

    Science.gov (United States)

    Crop nitrogen management is important world-wide, as much for small fields as it is for large operations. Developed as a non-destructive aid for estimating nitrogen content in rice crops, leaf color charts (LCC) are a numbered series of plastic panels that range from yellowgreen to dark green. By vi...

  8. Metabolic dependence of green tea on plucking positions revisited: a metabolomic study.

    Science.gov (United States)

    Lee, Jang-Eun; Lee, Bum-Jin; Hwang, Jeong-Ah; Ko, Kwang-Sup; Chung, Jin-Oh; Kim, Eun-Hee; Lee, Sang-Jun; Hong, Young-Shick

    2011-10-12

    The dependence of global green tea metabolome on plucking positions was investigated through (1)H nuclear magnetic resonance (NMR) analysis coupled with multivariate statistical data set. Pattern recognition methods, such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA), were employed for a finding metabolic discrimination among fresh green tea leaves plucked at different positions from young to old leaves. In addition to clear metabolic discrimination among green tea leaves, elevations in theanine, caffeine, and gallic acid levels but reductions in catechins, such as epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG), glucose, and sucrose levels were observed, as the green tea plant grows up. On the other hand, the younger the green tea leaf is, the more theanine, caffeine, and gallic acid but the lesser catechins accumlated in the green tea leaf, revealing a reverse assocation between theanine and catechins levels due to incorporaton of theanine into catechins with growing up green tea plant. Moreover, as compared to the tea leaf, the observation of marked high levels of theanine and low levels of catechins in green tea stems exhibited a distinct tea plant metabolism between the tea leaf and the stem. This metabolomic approach highlights taking insight to global metabolic dependence of green tea leaf on plucking position, thereby providing distinct information on green tea production with specific tea quality.

  9. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  10. American options under stochastic volatility

    NARCIS (Netherlands)

    Chockalingam, A.; Muthuraman, K.

    2011-01-01

    The problem of pricing an American option written on an underlying asset with constant price volatility has been studied extensively in literature. Real-world data, however, demonstrate that volatility is not constant, and stochastic volatility models are used to account for dynamic volatility

  11. Tea green leafhopper, Empoasca vitis, chooses suitable host plants by detecting the emission level of (3Z)-hexenyl acetate.

    Science.gov (United States)

    Xin, Z-J; Li, X-W; Bian, L; Sun, X-L

    2017-02-01

    Green leaf volatiles (GLVs) have been reported to play an important role in the host-locating behavior of several folivores that feed on angiosperms. However, next to nothing is known about how the green leafhopper, Empoasca vitis, chooses suitable host plants and whether it detects differing emission levels of GLV components among genetically different tea varieties. Here we found that the constitutive transcript level of the tea hydroperoxide lyase (HPL) gene CsiHPL1, and the amounts of (Z)-3-hexenyl acetate and of total GLV components are significantly higher in tea varieties that are susceptible to E. vitis (Enbiao (EB) and Banzhuyuan (BZY)) than in varieties that are resistant to E. vitis (Changxingzisun (CX) and Juyan (JY)). Moreover, the results of a Y-tube olfactometer bioassay and an oviposition preference assay suggest that (Z)-3-hexenyl acetate and (Z)-3-hexenol offer host and oviposition cues for E. vitis female adults. Taken together, the two GLV components, (Z)-3-hexenol and especially (Z)-3-hexenyl acetate, provide a plausible mechanism by which tea green leafhoppers distinguish among resistant and susceptible varieties. Future research should be carried out to obtain the threshold of the above indices and then assess their reasonableness. The development of practical detection indices would greatly improve our ability to screen and develop tea varieties that are resistant to E. vitis.

  12. Green Engineering

    Science.gov (United States)

    Green Engineering is the design, commercialization and use of processes and products that are feasible and economical while reducing the generation of pollution at the source and minimizing the risk to human health and the environment.

  13. Green Roofs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-08-01

    A New Technology Demonstration Publication Green roofs can improve the energy performance of federal buildings, help manage stormwater, reduce airborne emissions, and mitigate the effects of urban heat islands.

  14. Going Green

    Centers for Disease Control (CDC) Podcasts

    This podcast is for a general audience and provides information on how to recycle, re-use, and restore. It also covers the benefits of “Going Green" on the environment, health, and social interaction.

  15. Green lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin

    2010-01-01

    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  16. Green Nudging

    OpenAIRE

    Evans, Nicholas; Eickers, Stephanie; Geene, Leonie; Todorovic, Marijana; Villmow, Annika; Forschungsstelle für Umweltpolitik (FFU), Freie Universität Berlin

    2018-01-01

    Traditional environmental policy instruments have not always proven successful in fostering environmentally friendly behaviour. The question remains: how can policymakers tackle the attitude-behaviour gap when it comes to pro-environmental choices and sustainable lifestyles? One solution that has emerged is green nudging, a new and potentially promising policy tool born of behavioural economics and experimental psychology. This paper contributes to the current discussion surrounding green nud...

  17. Ozone Differentially Affects Perception of Plant Volatiles in Western Honey Bees.

    Science.gov (United States)

    Dötterl, Stefan; Vater, Marina; Rupp, Thomas; Held, Andreas

    2016-06-01

    Floral scents play a key role in mediating plant-pollinator interactions. Volatile organic compounds (VOCs) emitted by flowers are used by flower visitors as olfactory cues to locate flowers, both from a distance and at close range. More recently it has been demonstrated that reactive molecules such as ozone can modify or degrade VOCs, and this may impair the communication between plants and their pollinators. However, it is not known whether such reactive molecules also may affect the olfactory system of pollinators, and thus not only influence signal transmission but perception of the signal. In this study, we used electroantennographic measurements to determine the effect of increased levels of ozone on antennal responses in western honey bees (Apis mellifera L.). Linalool and 2-phenylethanol, both known to be involved in location of flowers by the bees, and (Z)-3-hexenyl acetate, a widespread green leaf volatile also detected by bees, were used. The results showed that ozone affected antennal responses to the different substances differently. Ozone decreased antennal responses to (Z)-3-hexenyl acetate, whereas responses to linalool and 2-phenylethanol were not influenced by ozone. Overall, the study does not provide evidence that pollination by honey bees is impaired by damage in the olfactory system of the bees caused by increased levels of ozone, at least when linalool and 2-phenylethanol are the attractive signals. However, the results also suggest that ozone can change the overall perception of an odor blend. This might have negative effects in pollination systems and other organismic interactions mediated by specific ratios of compounds.

  18. GC-MS Analysis of the Volatile Constituents in the Leaves of 14 Compositae Plants

    Directory of Open Access Journals (Sweden)

    Yiguang Wang

    2018-01-01

    Full Text Available The green organs, especially the leaves, of many Compositae plants possess characteristic aromas. To exploit the utility value of these germplasm resources, the constituents, mainly volatile compounds, in the leaves of 14 scented plant materials were qualitatively and quantitatively compared via gas chromatography-mass spectrometry (GC-MS. A total of 213 constituents were detected and tentatively identified in the leaf extracts, and terpenoids (especially monoterpene and sesquiterpene derivatives, accounting for 40.45–90.38% of the total compounds, were the main components. The quantitative results revealed diverse concentrations and compositions of the chemical constituents between species. Principal component analysis (PCA showed that different groups of these Compositae plants were characterized by main components of α-thujone, germacrene D, eucalyptol, β-caryophyllene, and camphor, for example. On the other hand, cluster memberships corresponding to the molecular phylogenetic framework, were found by hierarchical cluster analysis (HCA based on the terpenoid composition of the tested species. These results provide a phytochemical foundation for the use of these scented Compositae plants, and for the further study of the chemotaxonomy and differential metabolism of Compositae species.

  19. Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

    Science.gov (United States)

    Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

    2011-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

  20. Oil and stock market volatility: A multivariate stochastic volatility perspective

    International Nuclear Information System (INIS)

    Vo, Minh

    2011-01-01

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: → This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. → The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. → The volatility in each market is very persistent. → Innovations that hit either market can affect the volatility in the other market. → The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  1. 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

  2. Effects of Water Solutions on Extracting Green Tea Leaves

    Directory of Open Access Journals (Sweden)

    Wen-Ying Huang

    2013-01-01

    Full Text Available This study investigates the effects of water solutions on the antioxidant content of green tea leaf extracts. Green teas prepared with tap water and distilled water were compared with respect to four antioxidant assays: total phenol content, reducing power, DMPD assay, and trolox equivalent antioxidant capacity assay. The results indicate that green tea prepared with distilled water exhibits higher antioxidant activity than that made with tap water. The high performance liquid chromatography showed that major constituents of green tea were found in higher concentrations in tea made with distilled water than in that made with tap water. This could be due to less calcium fixation in leaves and small water clusters. Water solutions composed of less mineralisation are more effective in promoting the quality of green tea leaf extracts.

  3. Isoprene emission by poplar is not important for the feeding behaviour of poplar leaf beetles

    OpenAIRE

    M?ller, Anna; Kaling, Moritz; Faubert, Patrick; Gort, Gerrit; Smid, Hans M; Van Loon, Joop JA; Dicke, Marcel; Kanawati, Basem; Schmitt-Kopplin, Philippe; Polle, Andrea; Schnitzler, J?rg-Peter; Rosenkranz, Maaria

    2015-01-01

    Background Chrysomela populi (poplar leaf beetle) is a common herbivore in poplar plantations whose infestation causes major economic losses. Because plant volatiles act as infochemicals, we tested whether isoprene, the main volatile organic compound (VOC) produced by poplars (Populus x canescens), affects the performance of C. populi employing isoprene emitting (IE) and transgenic isoprene non-emitting (NE) plants. Our hypothesis was that isoprene is sensed and affects beetle orientation or ...

  4. Volatile liquid storage system

    International Nuclear Information System (INIS)

    Laverman, R.J.; Winters, P.J.; Rinehart, J.K.

    1992-01-01

    This patent describes a method of collecting and abating emission from a volatile liquid in an above ground storage tank. It comprises the liquid storage tank having a bottom, a vertical cylindrical circular wall having a lower edge portion joined to the bottom, and an external fixed roof, the tank having an internal floating roof floating on a volatile liquid stored in the tank, and air vent means in the tank in communication with a vapor space in the tank constituting at least the space above the floating roof when the floating roof floats on a predetermined maximum volume of volatile liquid in the tank; permitting ambient air; pumping emission laden air from the tank vapor space above the floating roof; and by means of the emissions abatement apparatus eliminating most of the emission from the emissions laden air with formation of a gaseous effluent and then discharging the resulting gaseous effluent to the atmosphere

  5. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  6. Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

    Science.gov (United States)

    Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

    2016-08-01

    First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork.

  7. Green banking

    Directory of Open Access Journals (Sweden)

    Maja Drobnjaković

    2013-06-01

    Full Text Available There is an urgent need to march towards “low - carbon economy”. Global challenges of diminishing fossil fuel reserves, climate change, environmental management and finite natural resources serving an expanding world population - these reasons mean that urgent action is required to transition to solutions which minimize environmental impact and are sustainable. We are at the start of the low - carbon revolution and those that have started on their low - carbon journey already are seeing benefits such as new markets and customers, improved economic, social and environmental performance, and reduced bills and risks. Green investment banks offer alternative financial services: green car loans, energy efficiency mortgages, alternative energy venture capital, eco - savings deposits and green credit cards. These items represent innovative financial products.

  8. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock ma...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...

  9. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process....... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  10. Green times

    International Nuclear Information System (INIS)

    Hasenclever, W.D.; Hasenclever, C.

    1982-01-01

    The authors, founding members of the ''Green Party'' have in mind to make a very personal contribution to a better understanding of the present political situation which, although it seems to have reached a deadlock, still offers positive chances and prospects. New approaches in policy are mentioned which may help to overcome the present state of resignation of many adolescents and adults. Among other things, they describe themselves setting out for new pathways, the ''Greens'' in Parliament, prospect for the future, opportunities of the ecologically oriented economic policy. Finally, they call upon the reader to think and develop further under the motto ''What we all can do''. (HSCH) [de

  11. CONTROLE QUÍMICO DO PULGÃO VERDE (Myzus persicae Sulzer, 1776 E DA VAQUINHA (Diabrotica speciosa Germ., 1824 NA CULTURA DO TOMATE RASTEIRO CHEMICAL CONTROL OF THE GREEN PEACH APHID (Myzus persicae, SULZER AND TOMATO LEAF BEETLE (Diabrotica speciosa, GERMAR IN TOMATO PLANTS

    Directory of Open Access Journals (Sweden)

    Danilo Couto

    2007-09-01

    Full Text Available

    O efeito de cinco inseticidas aplicados no tomateiro (Lycopersicum sculentum Mill, visando ao controle do pulgão verde, Myzus persicae SULZER e de vaquinha, Diabrotica speciosa GERM, foi testado em um experimento realizado na área experimental do Departamento de Horticultura da Escota de Agronomia da Universidade Federal de Goiás, no período de maio a setembro de 1994. Os tratamentos foram aplicados via pulverização e constaram de Bulldock 125 SC (dosagem de 100 ml/ 100 1 de água; Bulldock 50 CE (25 e 30 ml/100 l de água; Tamaron BR (100 ml/ 100 l de água; Orthene 750 BR (100 ml/ l00 1 de água e Folidol 600 (100 ml/l00 1 de água; e ainda uma testemunha (sem inseticida. Os resultados obtidos mostraram que todos os tratamentos foram eficientes no controle de M. persicae até sete dias após a aplicação. Aos 14 dias após a aplicação, o Bulldock 50 CE na dosagem de 25 ml/ 100 l de água e o Folidol 600 a 100 ml/ 100 l de água não apresentaram eficiência satisfatória. Com relação à D. speciosa, todos esses produtos foram igualmente eficientes até sete dias após aplicação.

    PALAVRAS-CHAVE: Myzus persicae; diabrotica speciosa; tomateiro; controle químico.

    A trial to control the green peach aphid myzus persicae and tomato leaf beetle Diabrotica speciosa was carried out in Goi

  12. Quantifying requirements volatility effects

    NARCIS (Netherlands)

    Kulk, G.P.; Verhoef, C.

    2008-01-01

    In an organization operating in the bancassurance sector we identified a low-risk IT subportfolio of 84 IT projects comprising together 16,500 function points, each project varying in size and duration, for which we were able to quantify its requirements volatility. This representative portfolio

  13. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong...

  14. Spectroscopic Study of Green Tea (Camellia sinensis) Leaves Extraction

    Science.gov (United States)

    Marzuki, A.; Suryanti, V.; Virgynia, A.

    2017-04-01

    This paper reports the analysis of UV-VIS-NIR absorption spectra of different concentrations of green tea (Camellia sinensis) leaf extract in two different solvent systems (chloroform and ethyl acetate). In those solvents, two different peaks characterizing green tea are observed at different wavelengths, namely 296 nm and 329 nm (extracted in chloroform) and 391 nm and 534 nm (extracted in ethyl acetate). We then investigated the absorption spectra change as function of green tea concentration in both solvents. We found that light absorption increases linearly with the increase of green tea concentration. Different wavelengths, however, respond this change differently. However, the way it changes is wavelength dependence.

  15. Manure application and ammonia volatilization

    NARCIS (Netherlands)

    Huijsmans, J.F.M.

    2003-01-01

    Keywords: manure application, ammonia volatilization, environmental conditions, application technique, incorporation technique, draught force, work organization, costs Livestock manure applied on farmland is an important source of ammonia (NH3) volatilization, and NH3 is a major atmospheric

  16. Going Green

    Science.gov (United States)

    Witkowsky, Kathy

    2009-01-01

    Going green saves money and can even make money. Sustainable practices promote better health, less absenteeism, and more productivity. They also attract students, who are paying increasing attention to schools' environmental policies. Beyond being the smart thing to do, administrators at the University of Washington say repeatedly, it's the right…

  17. Buying Green

    Science.gov (United States)

    Layng, T. V. Joe

    2010-01-01

    In "Buying Green," Joe Layng recognizes that, like all choices we make, our decisions as consumers are more likely to be influenced by their short-term consequences for us as individuals (price, quality) than they are by their long-term consequences for society (environmental impact). He believes that the equation can be tilted in favor of greener…

  18. Green pioneers.

    Science.gov (United States)

    Trueland, Jennifer

    The government has set tough targets for the NHS in England to reduce its carbon footprint. In this article, nurses and managers at Nottinghamshire Healthcare NHS Trust explain how a programme of 'greening' initiatives - including a trial of electric cars for community staff - have slashed the trust's CO2 output.

  19. Automatically Green

    DEFF Research Database (Denmark)

    Sunstein, Cass R.; Reisch, Lucia

    2014-01-01

    reasons include the power of suggestion; inertia and procrastination; and loss aversion. If well-chosen, green defaults are likely to have large effects in reducing the economic and environmental harms associated with various products and activities. Such defaults may or may not be more expensive...

  20. Automatically Green

    DEFF Research Database (Denmark)

    Sunstein, Cass R.; Reisch, Lucia

    reasons include the power of suggestion; inertia and procrastination; and loss aversion. If well-chosen, green defaults are likely to have large effects in reducing the economic and environmental harms associated with various products and activities. Such defaults may or may not be more expensive...

  1. Going Green

    Centers for Disease Control (CDC) Podcasts

    2008-04-18

    This podcast is for a general audience and provides information on how to recycle, re-use, and restore. It also covers the benefits of “Going Green" on the environment, health, and social interaction.  Created: 4/18/2008 by National Center for Environmental Health (NCEH), ATSDR.   Date Released: 5/8/2008.

  2. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  3. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  4. Essays on nonparametric econometrics of stochastic volatility

    NARCIS (Netherlands)

    Zu, Y.

    2012-01-01

    Volatility is a concept that describes the variation of financial returns. Measuring and modelling volatility dynamics is an important aspect of financial econometrics. This thesis is concerned with nonparametric approaches to volatility measurement and volatility model validation.

  5. Volatile-Mediated within-Plant Signaling in Hybrid Aspen: Required for Systemic Responses.

    Science.gov (United States)

    Li, Tao; Blande, James D

    2017-04-01

    Plant volatiles play crucial roles in signaling between plants and their associated community members, but their role in within-plant signaling remains largely unexplored, particularly under field conditions. Using a system comprising the hybrid aspen (Populus tremula x tremuloides) and the specialized herbivorous leaf beetle (Phratora laticollis) and, combining field, greenhouse and laboratory experiments, we examined whether local damage triggered systemic responses in undamaged branches that lack vascular connection to the damaged branches, and to what extent this was caused by airborne volatile signals versus internal signals. An experiment tracing dye through the vasculature of saplings revealed no downward movement of the dye from upper to lower branches, suggesting a lack of vascular connectivity among branches. However, we found under both field and laboratory conditions that herbivore feeding on upper branches elicited volatile emissions by undamaged lower branches. Greenhouse experiments manipulating air contact between damaged and undamaged branches showed that systemic induction of volatiles was almost eliminated when air contact was interrupted. Our findings clearly demonstrate that herbivore-induced volatiles overcome vascular constraints and mediate within-plant signaling. Further, we found that volatile signaling led to induction of different classes of volatiles under field and environment controlled conditions, with a weaker response observed in the field. This difference not only reflects the dose- and time-dependent nature of volatile signaling, but also points out that future studies should focus more on field observations to better understand the ecological role of volatile-mediated within-plant signaling.

  6. Pengaruh Green Marketing Hotel Terhadap Green Consumer Behavior

    OpenAIRE

    Yo Fernandez, Eunike Christe; Tjoanda, Evelyn

    2017-01-01

    Penelitian ini dilakukan untuk mengetahui pengaruh dari green marketing hotel terhadap green consumer behavior. Green marketing memiliki 3 dimensi, yaitu green product, green price, dan green promotion. Penelitian ini melibatkan 272 responden masyarakat Surabaya dan menggunakan metode regresi linear berganda. Hasil penelitian menunjukkan bahwa green product dan green price berpengaruh secara positif dan signifikan sedangkan green promotion berpengaruh namun tidak signifikan terhadap green con...

  7. Physiological Characterization and Comparative Transcriptome Analysis of White and Green Leaves of Ananas comosus var. bracteatus

    OpenAIRE

    Li, Xia; Kanakala, Surapathrudu; He, Yehua; Zhong, Xiaolan; Yu, Sanmiao; Li, Ruixue; Sun, Lingxia; Ma, Jun

    2017-01-01

    Leaf coloration is one of the most important and attractive characteristics of Ananas comosus var. bracteatus. The chimeric character is not stable during the in vitro tissue culturing. Many regenerated plants lost economic values for the loss of the chimeric character of leaves. In order to reveal the molecular mechanisms involved in the albino phenotype of the leaf cells, the physiological and transcriptional differences between complete white (CWh) and green (CGr) leaf cells of A. comosus ...

  8. Green Computing

    Directory of Open Access Journals (Sweden)

    K. Shalini

    2013-01-01

    Full Text Available Green computing is all about using computers in a smarter and eco-friendly way. It is the environmentally responsible use of computers and related resources which includes the implementation of energy-efficient central processing units, servers and peripherals as well as reduced resource consumption and proper disposal of electronic waste .Computers certainly make up a large part of many people lives and traditionally are extremely damaging to the environment. Manufacturers of computer and its parts have been espousing the green cause to help protect environment from computers and electronic waste in any way.Research continues into key areas such as making the use of computers as energy-efficient as Possible, and designing algorithms and systems for efficiency-related computer technologies.

  9. 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.

  10. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection...... and identified or characterized by gas chromatography-mass spectrometry. A total of 120 VOCs were characterized by retention index and mass spectra. Fifty-three compounds were characterized as terpenoid compounds, among which 18 could be identified. Among the VOCs were alkanes, alkenes, alcohols, esters, ketones....... The relationship between the excretion of geosmin and the production of spores was examined for one isolate. A good correlation between headspace geosmin and the number of spores was observed, suggesting that VOCs could be used to indicate the activity of these microorganisms in heterogeneous substrates....

  11. Green toxicology.

    Science.gov (United States)

    Maertens, Alexandra; Anastas, Nicholas; Spencer, Pamela J; Stephens, Martin; Goldberg, Alan; Hartung, Thomas

    2014-01-01

    Historically, early identification and characterization of adverse effects of industrial chemicals was difficult because conventional toxicological test methods did not meet R&D needs for rapid, relatively inexpensive methods amenable to small amounts of test material. The pharmaceutical industry now front-loads toxicity testing, using in silico, in vitro, and less demanding animal tests at earlier stages of product development to identify and anticipate undesirable toxicological effects and optimize product development. The Green Chemistry movement embraces similar ideas for development of less toxic products, safer processes, and less waste and exposure. Further, the concept of benign design suggests ways to consider possible toxicities before the actual synthesis and to apply some structure/activity rules (SAR) and in silico methods. This requires not only scientific development but also a change in corporate culture in which synthetic chemists work with toxicologists. An emerging discipline called Green Toxicology (Anastas, 2012) provides a framework for integrating the principles of toxicology into the enterprise of designing safer chemicals, thereby minimizing potential toxicity as early in production as possible. Green Toxicology`s novel utility lies in driving innovation by moving safety considerations to the earliest stage in a chemical`s lifecycle, i.e., to molecular design. In principle, this field is no different than other subdisciplines of toxicology that endeavor to focus on a specific area - for example, clinical, environmental or forensic toxicology. We use the same principles and tools to evaluate an existing substance or to design a new one. The unique emphasis is in using 21st century toxicology tools as a preventative strategy to "design out" undesired human health and environmental effects, thereby increasing the likelihood of launching a successful, sustainable product. Starting with the formation of a steering group and a series of workshops

  12. Green Gold

    International Nuclear Information System (INIS)

    Salamandra Martinez, Carlos

    2004-01-01

    The main purpose of this work is to offer a general panoramic of the processes or experiences pilot that are carried out in the Project Green Gold, as strategy of environmental sustainability and organizational invigoration in Choco, especially in the 12 communities of the municipalities of Tado and Condoto. It is also sought to offer a minimum of information on the techniques of handmade production and to show the possibilities to carry out in a rational way the use and use of the natural resources. The Project Green Gold is carried out by the Corporation Green Gold (COV) and co-financed with resources of international and national character, the intervention of the financial resources it achievement mainly for the use of clean processes in the extraction stages and metals benefit. The project is centered primarily in the absence of use of products or toxic substances as the mercury, fair trade, organizational invigoration, execution of 11 approaches and certification of the metals Gold and Platinum. The COV, it has come executing the proposal from the year 2001 with the premise of contributing to the balance between the rational exploitation of the natural resources and the conservation of the environment in the Choco. In the project they are used technical handmade characteristic of the region framed inside the mining activity and production activities are diversified in the productive family units. Those producing with the support of entities of juridical character, specify the necessary game rules for the extraction and products commercialization

  13. Minimum Tracking Error Volatility

    OpenAIRE

    Luca RICCETTI

    2010-01-01

    Investors assign part of their funds to asset managers that are given the task of beating a benchmark. The risk management department usually imposes a maximum value of the tracking error volatility (TEV) in order to keep the risk of the portfolio near to that of the selected benchmark. However, risk management does not establish a rule on TEV which enables us to understand whether the asset manager is really active or not and, in practice, asset managers sometimes follow passively the corres...

  14. Recovering volatile liquids

    Energy Technology Data Exchange (ETDEWEB)

    Bregeat, J H

    1925-07-30

    The products of hydrogenation of alicyclic compounds, such as terpenes, for example, pinene or oil of turpentine, are used as washing liquids for absorbing vapours of volatile liquids from gases, such as natural gases from petroliferous regions, gases from the distillation of coal, lignite, schist, peat, etc. or from the cracking of heavy oils. Other liquids such as tar oils vaseline oils, cresols, etc. may be added.

  15. Understanding Interest Rate Volatility

    OpenAIRE

    Volker, Desi

    2016-01-01

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochast...

  16. The memory of volatility

    Directory of Open Access Journals (Sweden)

    Kai R. Wenger

    2018-03-01

    Full Text Available The focus of the volatility literature on forecasting and the predominance of theconceptually simpler HAR model over long memory stochastic volatility models has led to the factthat the actual degree of memory estimates has rarely been considered. Estimates in the literaturerange roughly between 0.4 and 0.6 - that is from the higher stationary to the lower non-stationaryregion. This difference, however, has important practical implications - such as the existence or nonexistenceof the fourth moment of the return distribution. Inference on the memory order is complicatedby the presence of measurement error in realized volatility and the potential of spurious long memory.In this paper we provide a comprehensive analysis of the memory in variances of international stockindices and exchange rates. On the one hand, we find that the variance of exchange rates is subject tospurious long memory and the true memory parameter is in the higher stationary range. Stock indexvariances, on the other hand, are free of low frequency contaminations and the memory is in the lowernon-stationary range. These results are obtained using state of the art local Whittle methods that allowconsistent estimation in presence of perturbations or low frequency contaminations.

  17. Ammonia volatilization from crop residues and frozen green manure crops

    NARCIS (Netherlands)

    Ruijter, de F.J.; Huijsmans, J.F.M.; Rutgers, B.

    2010-01-01

    Agricultural systems can lose substantial amounts of nitrogen (N). To protect the environment, the European Union (EU) has adopted several directives that set goals to limit N losses. National Emission Ceilings (NEC) are prescribed in the NEC directive for nitrogen oxides and ammonia. Crop residues

  18. Temperature-sensitive leaf color mutation in rice

    International Nuclear Information System (INIS)

    Shu Qingyao; Liu Guifu; Xia Yingwu

    1996-01-01

    Studies on the leaf color appearance of 4 chlorophyll-deficient mutation lines both in field and in phytotron were carried out. The mutation lines were induced by 60 Co gamma rays, and showed that white or yellow leaves at seedling stage were quite different from their-parent 2177 S, a thermal sensitive genie male sterile line and any other rice materials. The temperature had great influence on the expression of leaf color at seedling stage in the mutation lines. the leaf color was white at 30∼35 degree C for the lines W 4 and W 11 . The chlorophyll content of 1.5-leaf-age seedlings was 0.0219 and 0.0536 mg/g FW respectively for W 4 and W 11 at 35 degree C. When the temperature dropped to 20∼25 degree C, the seedlings showed yellow or yellowish and the chlorophyll content reached to 0.2410 and 0.3431 mg/g FW at 25 degree C, respectively. However, the responses to temperature for W 17 and W 25 were just the opposite. They were white at 20∼25 degree C, but appeared greenish at 30∼35 degree C. The chlorophyll content increased from 0.0813 and 0.0172 mg/g FW at 25 degree C to 1.0570 and 1.1367 mg/g FW at 35 degree C for the lines W 1 -7 and W 25 , respectively. The parent line 2177 S showed normal green and the chlorophyll content was between 2.108 and 2.118 mg/g FW. The W 11 is exception, which showed yellow to light green in lifetime, and all the mutation lines could convert to normal green after the extension of the fourth leaf. The chlorophyll content of 3.5-leaf-age W 4 and W 17 seedlings grown under 25 degree C reached to 2.2190 and 1.993 mg/g FW, which was about 86. 6% and 81.1% of that of 2177 S at the same stage. When grown at the temperature bellow 20 degree C, W 25 maintained white and could not changed into green after the 4th leaf extension, and showed a conditional lethal status

  19. Greens of the European Green Capitals

    Science.gov (United States)

    Cömertler, Seval

    2017-10-01

    Well established and maintained green areas have a key role on reaching the high quality of life and sustainability in urban environments. Therefore, green areas must be carefully accounted and evaluated in the urban planning affairs. In this context, the European Green Capitals, which attach a great importance to the green areas, have a great potential to act as a role model for both small and big cities in all around the world. These leading cities (chronologically, Stockholm, Hamburg, Vitoria-Gasteiz, Nantes, Copenhagen, Bristol, Ljubljana, Essen and Nijmegen) are inspiring for the other cities which seek to achieve more sustainable and environmentally friendly places through green areas. From this point of view, the aim of this paper was to investigate the green areas of the European Green Capitals. The paper covered whole European Green Capitals, and the application form of each Green Capital was used as a primary data source. Consequently, the paper put forwarded that the European Green Capitals have considerably large amount and high proportion of green areas. Further, these cities provide an excellent access to the public green areas. As a result of abundant provision and proper distribution, the almost all citizens in most of the Green Capitals live within a distance of 300 meters to a green area. For further researches, the paper suggested that these green capitals should be investigated in terms of their efforts, measures, goals and plans, policies and implications to administer, to protect, to enhance and to expand the green areas.

  20. 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.

  1. Effects of near ultraviolet and green radiations on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.M.; Edsall, P.C.; Gentile, A.C.

    1965-01-01

    Selective removal of near ultraviolet and green wavelengths from white light permitted enhanced growth of marigold, tomato, corn, and Impatiens plants, Chlamydomonas cells and the mycelium of Sordaria. Additions of near ultraviolet and green radiations caused repressions in the growth of marigold and Sordaria. These wavelengths do not alter the oxidative mechanisms of mitochondria, intact algal cells or marigold leaf tissues. The capacity for chlorophyll and carotenoid synthesis by Euglena cells was unaffected by these wavelengths. 23 references, 2 figures, 4 tables.

  2. Tuning Transpiration by Interfacial Solar Absorber-Leaf Engineering.

    Science.gov (United States)

    Zhuang, Shendong; Zhou, Lin; Xu, Weichao; Xu, Ning; Hu, Xiaozhen; Li, Xiuqiang; Lv, Guangxin; Zheng, Qinghui; Zhu, Shining; Wang, Zhenlin; Zhu, Jia

    2018-02-01

    Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber-water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber-leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber-leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle.

  3. Tuning Transpiration by Interfacial Solar Absorber‐Leaf Engineering

    Science.gov (United States)

    Zhuang, Shendong; Zhou, Lin; Xu, Weichao; Xu, Ning; Hu, Xiaozhen; Li, Xiuqiang; Lv, Guangxin; Zheng, Qinghui; Zhu, Shining

    2017-01-01

    Abstract Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber–water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber–leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber‐leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle. PMID:29619300

  4. Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration, humidity effect and reduced electric field dependency.

    Science.gov (United States)

    Pang, Xiaobing

    2015-06-01

    Green leaf volatiles (GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds (BVOCs). Proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field, etc. In this study the influence of gas humidity and the effect of reduced field (E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to 10 ncps/ppbv (normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity (RH) at 21°C, with the exception of (E)-2-hexenol. Product ion branching ratios were also affected by humidity, with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field (E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N. Copyright © 2015. Published by Elsevier B.V.

  5. Degradation of pheromone and plant volatile components by a same odorant-degrading enzyme in the cotton leafworm, Spodoptera littoralis.

    Directory of Open Access Journals (Sweden)

    Nicolas Durand

    Full Text Available Odorant-Degrading Enzymes (ODEs are supposed to be involved in the signal inactivation step within the olfactory sensilla of insects by quickly removing odorant molecules from the vicinity of the olfactory receptors. Only three ODEs have been both identified at the molecular level and functionally characterized: two were specialized in the degradation of pheromone compounds and the last one was shown to degrade a plant odorant.Previous work has shown that the antennae of the cotton leafworm Spodoptera littoralis, a worldwide pest of agricultural crops, express numerous candidate ODEs. We focused on an esterase overexpressed in males antennae, namely SlCXE7. We studied its expression patterns and tested its catalytic properties towards three odorants, i.e. the two female sex pheromone components and a green leaf volatile emitted by host plants.SlCXE7 expression was concomitant during development with male responsiveness to odorants and during adult scotophase with the period of male most active sexual behaviour. Furthermore, SlCXE7 transcription could be induced by male exposure to the main pheromone component, suggesting a role of Pheromone-Degrading Enzyme. Interestingly, recombinant SlCXE7 was able to efficiently hydrolyze the pheromone compounds but also the plant volatile, with a higher affinity for the pheromone than for the plant compound. In male antennae, SlCXE7 expression was associated with both long and short sensilla, tuned to sex pheromones or plant odours, respectively. Our results thus suggested that a same ODE could have a dual function depending of it sensillar localisation. Within the pheromone-sensitive sensilla, SlCXE7 may play a role in pheromone signal termination and in reduction of odorant background noise, whereas it could be involved in plant odorant inactivation within the short sensilla.

  6. The influence of soil salinity on volatile organic compounds emission and photosynthetic parameters of Solanum lycopersicum L. varieties

    Directory of Open Access Journals (Sweden)

    Tomescu Daniel

    2017-05-01

    Full Text Available Soil salinity is one of the best known stress factors of plants that can lead to crop yield reduction. Therefore, it is important to identify new tolerance varieties of plants that can grow on saline soils. We have studied the influence of salt on five different tomato varieties from the Western region of Romania and compared them with a commercial hybrid and found that one of them (Rudna is a very salt-tolerant variety (up to 200 mM NaCl. The assimilation rates and stomata conductance of water vapour are affected by salinity but some of the local varieties of tomato exhibit quite good tolerance. We found that all plants under salinity stress emit (Z-3-hexenol (a C6, green leaf volatile and the emission of all terpenes increased in proportion to the salt concentration. The emission of three terpenes, (Z-beta-ocimene. 2-carene and beta-phellandrene, have been quantitatively correlated with salt concentration.

  7. Chemical Compositions of Achillea sivasica: Different Plant Part Volatiles, Enantiomers and Fatty Acids

    Directory of Open Access Journals (Sweden)

    Gülmira Özek

    2018-03-01

    Full Text Available In the present work, Microsteam distillation - Solid phase microextraction (MSD-SPME and hydrodistillation (HD techniques were applied to obtain volatiles from Achillea sivasica, an endemic species from Turkey. GC-FID and GC/MS analysis revealed that 1,8-cineole (22.1% and a -pinene (9.3% were the main constituents of the hydrodistilled flower volatiles. (Z- b -Farnesene (23.9%, decanoic acid (10.1%, b- eudesmol (8.0%, tricosane (7.3% and hexadecanoic acid (7.2% were the main volatiles obtained from flowers by MSD-SPME. The leaf volatiles obtained by HD contained camphor (9.0%, b -pinene (6.9%, 1,8-cineole (6.7%, a -pinene (6.7% and a -bisabolol (6.6% as the main constituents while the leaf volatiles obtained by MSD-SPME technique were rich in (E-geranyl acetone (10.5%, (E- b -ionone (10.3%, camphor (10.2%, 1,8-cineole (9.6%, longiverbenone (7.9%, b -eudesmol (7.5%, isopropyl myristate (6.7% and epi- a -bisabolol (6.4%. The root volatiles were rich in longiverbenone (14.1%, (E-geranyl acetone (9.3%, nonanol (12.1% and decanol (12.5%. The enantiomeric distribution of the major volatile constituents was analyzed by using different b -cyclodextrin chiral columns. (1R-(+- a -Pinene, (1S-(-- b -pinene, (4R-(+-limonene, (1R,3S,5R-(--trans-pinocarveol, (1S,2R,4S-(--borneol, (2S-(-- a -bisabolol were detected as dominant enantiomers. The lipids extracted from the flower and leaf with Folch method and methylated with BF 3 reagent contained common acids: linolenic, linoleic, hexadecanoic acids. Oleic and stearic acids were detected particularly in high amount in the flower lipids

  8. Monitoring volatile anaesthetic agents

    International Nuclear Information System (INIS)

    Russell, W.J.

    2000-01-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  9. Monitoring volatile anaesthetic agents

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W J [Royal Adelaide Hospital, SA (Australia). Department of Anaesthesia and Intensive Care

    2000-12-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  10. Green Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Patten, John

    2013-12-31

    Green Manufacturing Initiative (GMI): The initiative provides a conduit between the university and industry to facilitate cooperative research programs of mutual interest to support green (sustainable) goals and efforts. In addition to the operational savings that greener practices can bring, emerging market demands and governmental regulations are making the move to sustainable manufacturing a necessity for success. The funding supports collaborative activities among universities such as the University of Michigan, Michigan State University and Purdue University and among 40 companies to enhance economic and workforce development and provide the potential of technology transfer. WMU participants in the GMI activities included 20 faculty, over 25 students and many staff from across the College of Engineering and Applied Sciences; the College of Arts and Sciences' departments of Chemistry, Physics, Biology and Geology; the College of Business; the Environmental Research Institute; and the Environmental Studies Program. Many outside organizations also contribute to the GMI's success, including Southwest Michigan First; The Right Place of Grand Rapids, MI; Michigan Department of Environmental Quality; the Michigan Department of Energy, Labor and Economic Growth; and the Michigan Manufacturers Technical Center.

  11. Green chemistry

    International Nuclear Information System (INIS)

    Warner, John C.; Cannon, Amy S.; Dye, Kevin M.

    2004-01-01

    A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

  12. Green urbanity

    Directory of Open Access Journals (Sweden)

    Alenka Fikfak

    2012-01-01

    Full Text Available Tourism and other culture-based types of small business, which are the leitmotif in the planning of the Europark Ruardi, are becoming the guiding motif in the spatial development of urban centres that are influenced by dynamic transformation processes. The system should build upon the exploitation of both local and regional environmental features. This would encourage the quest for special environmental features, with an emphasis on their conservation, i.e. sustainable development, and connections in a wider context.The Europark is seen as a new strategic point of the Zasavje Region (the region of the central Sava Valley, which is linked to other important points in a region relevant for tourism. Due to the "smallness" of the region and/or the proximity of such points, development can be fast and effective. The interaction of different activities in space yields endless opportunities for users, who choose their own goals and priorities in the use of space. Four theme areas of the Europark area planning are envisaged. The organisation of activities is based on the composition of the mosaic field patterns, where green fields intertwine with areas of different, existing and new, urban functions. The fields of urban and recreation programmes are connected with a network of green areas and walking trails, along which theme park settings are arranged.

  13. Green shipping management

    CERN Document Server

    Lun, Y H Venus; Wong, Christina W Y; Cheng, T C E

    2016-01-01

    This book presents theory-driven discussion on the link between implementing green shipping practices (GSP) and shipping firm performance. It examines the shipping industry’s challenge of supporting economic growth while enhancing environmental performance. Consisting of nine chapters, the book covers topics such as the conceptualization of green shipping practices (GSPs), measurement scales for evaluating GSP implementation, greening capability, greening and performance relativity (GPR), green management practice, green shipping network, greening capacity, and greening propensity. In view of the increasing quest for environment protection in the shipping sector, this book provides a good reference for firms to understand and evaluate their capability in carrying out green operations on their shipping activities.

  14. From green architecture to architectural green

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    that describes the architectural exclusivity of this particular architecture genre. The adjective green expresses architectural qualities differentiating green architecture from none-green architecture. Currently, adding trees and vegetation to the building’s facade is the main architectural characteristics...... they have overshadowed the architectural potential of green architecture. The paper questions how a green space should perform, look like and function. Two examples are chosen to demonstrate thorough integrations between green and space. The examples are public buildings categorized as pavilions. One......The paper investigates the topic of green architecture from an architectural point of view and not an energy point of view. The purpose of the paper is to establish a debate about the architectural language and spatial characteristics of green architecture. In this light, green becomes an adjective...

  15. Ambient Volatility of Triethyl Phosphate

    Science.gov (United States)

    2017-08-01

    of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second

  16. Responses of rubber leaf phenology to climatic variations in Southwest China

    Science.gov (United States)

    Zhai, De-Li; Yu, Haiying; Chen, Si-Chong; Ranjitkar, Sailesh; Xu, Jianchu

    2017-11-01

    The phenology of rubber trees (Hevea brasiliensis) could be influenced by meteorological factors and exhibits significant changes under different geoclimates. In the sub-optimal environment in Xishuangbanna, rubber trees undergo lengthy periods of defoliation and refoliation. The timing of refoliation from budburst to leaf aging could be affected by powdery mildew disease (Oidium heveae), which negatively impacts seed and latex production. Rubber trees are most susceptible to powdery mildew disease at the copper and leaf changing stages. Understanding and predicting leaf phenology of rubber trees are helpful to develop effective means of controlling the disease. This research investigated the effect of several meteorological factors on different leaf phenological stages in a sub-optimal environment for rubber cultivation in Jinghong, Yunnan in Southwest China. Partial least square regression was used to quantify the relationship between meteorological factors and recorded rubber phenologies from 2003 to 2011. Minimum temperature in December was found to be the critical factor for the leaf phenology development of rubber trees. Comparing the delayed effects of minimum temperature, the maximum temperature, diurnal temperature range, and sunshine hours were found to advancing leaf phenologies. A comparatively lower minimum temperature in December would facilitate the advancing of leaf phenologies of rubber trees. Higher levels of precipitation in February delayed the light green and the entire process of leaf aging. Delayed leaf phenology was found to be related to severe rubber powdery mildew disease. These results were used to build predictive models that could be applied to early warning systems of rubber powdery mildew disease.

  17. Both phenolic and non-phenolic green tea fractions inhibit migration of cancer cells

    Science.gov (United States)

    Green tea consumption is associated with chemoprevention of many cancer types. Fresh tea leaves are rich in polyphenolic catechins, which can constitute up to 30% of the dry leaf weight. While the polyphenols of green tea have been well investigated, it is still largely unknown, whether or not non-p...

  18. The Volatile Composition of Portuguese Propolis Towards its Origin Discrimination

    Directory of Open Access Journals (Sweden)

    Soraia I. Falcão

    2016-03-01

    Full Text Available The volatiles from thirty six propolis samples collected from six different geographical locations in Portugal (mainland, Azores archipelago and Madeira Island were evaluated. Populus x canadensis Moenchen leaf-buds and Cistus ladanifer L. branches essential oils were comparatively analysed. The essential oils were isolated by hydrodistillation and analysed by Gas Chromatography (GC and Gas Chromatography-Mass Spectrometry (GC-MS. Cluster analysis based on propolis samples volatiles chemical composition defined three main clusters, not related to sample site collection. Cluster I grouped 28 samples with high relative amounts of oxygen-containing sesquiterpenes (20-77%, while cluster II grouped 7 samples rich in oxygen-containing monoterpenes (9-65% and the only sample from cluster III was monoterpene hydrocarbons rich (26%. Although Populus x canadensis and Cistus ladanifer were associated as resin sources of Portuguese propolis, other Populus species as well as plants like Juniperus genus may contribute to the resin in specific geographical locations.

  19. Investigating the Alometric Relationships between Leaf Area and Some of Vegetative Characteristics in SC704 Corn Hybrid

    Directory of Open Access Journals (Sweden)

    E Zeinali

    2016-10-01

    Full Text Available Introduction Since the leaves are the main source of production of photosynthetic substances in plants, dry matter production and crop yield potential is largely dependent on the leaf surface, and many environmental changes affect growth and yield through changes in leaf area. Hence, green leaf area per plant and leaf area index is measured in almost all studies of crop physiology to understand the mechanism of yield alteration. However, measurement of leaf area compared with the other traits such as plant height and total plant dry weight is very difficult, need to precision instruments and spend more time and cost. Therefore, according to the allometric relationships in plants, extensive studies were done to find the relationship between leaf area and the other plant traits that their measurement is easier, faster and cheaper, and does not require expensive equipment. Using these relationships will be used to estimate plant leaf area with acceptable accuracy without measuring. Plant traits that have high correlation with leaf area and usually use to estimate the plant leaf area are the number of leaves or nodes per main stem, plant height, leaf dry weight and dry weight of vegetative parts of the plant. Allometric equations was used successfully to calculate leaf area for various crops such as cotton, wheat, chickpea, faba bean, peanuts, soybean and sweet sorghum. This study was conducted to obtain the allometric relationships between green leaf area (cm2 per plant with number of leaves or nodes per main stem, plant height, green leaf dry weight and dry weight of vegetative parts of the plant (gram per plant, and investigating the effect of plant density and planting date on these relationships in SC704 corn (Zea mays L. hybrid. Materials and Methods This study was conducted at Gorgan University of Agricultural Sciences and Natural Resources farm located at latitude 36 o 51’ N, longitude 54 o27’ E and altitude of 13 meters above sea level

  20. Differences between winter oilseed rape (Brassica napus L.) cultivars in nitrogen starvation-induced leaf senescence are governed by leaf-inherent rather than root-derived signals

    Czech Academy of Sciences Publication Activity Database

    Koeslin-Findeklee, F.; Becker, M. A.; van der Graaff, E.; Roitsch, Thomas; Horst, W. J.

    2015-01-01

    Roč. 66, č. 13 (2015), s. 3669-3681 ISSN 0022-0957 Institutional support: RVO:67179843 Keywords : Brassica napus * cytokinins * genotypic differences * leaf senescence * nitrogen efficiency * nitrogen starvation * reciprocal grafting * stay-green Subject RIV: EH - Ecology, Behaviour Impact factor: 5.677, year: 2015

  1. Ionizing radiation effects on volatiles formation in Camellia sinensis (L) teas

    International Nuclear Information System (INIS)

    Fanaro, Gustavo Bernardes

    2009-01-01

    The aim of this study was to evaluate the effects of radiation on volatile formation in white, green, oolong and black teas. Samples were irradiated in room temperature at 60 Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20 kGy. The volatiles organic compound was extracted by hydro distillation and the extract was separated and identified by gas chromatography mass spectrometry (GCMS) analysis. The results show that the volatiles formations are directly proportional to the increase of radiation dose. The white tea showed less influence of ionizing radiation, as 37.86% of the compounds were stable at all doses of radiation and formed 47.53% of new compounds after irradiation. The green tea was the tea that has the greatest influence of radiation effects, increasing 66.12% of volatiles identified in relation to the control sample and only 21.77% of volatiles found naturally were resistant to all doses of radiation. The oolong tea, despite suffering a partial enzymatic treatment, was the second tea that has least interference of radiation in increasing the formation of new volatile. >From this tea, was able to detect 49.59% of new compounds after irradiation and 30.08% of the compounds found naturally were also found after irradiation. The black tea has the second greatest influence of radiation on formation of new volatile (60.94%) and only 17.97% of all identified compounds were not degraded after radiation. (author)

  2. Volatiles from solids

    Energy Technology Data Exchange (ETDEWEB)

    Loughrey, C T

    1939-08-24

    To remove volatiles from solids, such as oil shale, gases, and/or vapours are passed through a mass of the materials, the vapours and gases separated, and the vapours condensed. The volatile-containing solid materials are fed to a retort, and a shaft is driven to rotate an impeller so as to displace the liquid and create a vortex tube, which draws in gas from the atmosphere through an intake, twyer, interstices in the material in the retort, a conduit, chamber, tubes, another chamber and cylinder. This gas is carried outwardly and upwardly by the vortices in the liquid and is carried to discharge through three conduits. The vapours entrained by the gas are part condensed in the liquid and the remainder directed to a condenser. Steam may be delivered to the twyer through a nozzle of a pipe, with or without air, and combustible hydrocarbon fuel may be fed through the burner nozzle or solid fuel may be directed from feeder and combusted in the twyer.

  3. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  4. Volatility Mean Reversion and the Market Price of Volatility Risk

    NARCIS (Netherlands)

    Boswijk, H.P.

    2001-01-01

    This paper analyzes sources of derivative pricing errors in a stochastic volatility model estimated on stock return data. It is shown that such pricing errors may reflect the existence of a market price of volatility risk, but also may be caused by estimation errors due to a slow mean reversion in

  5. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    The persistent nature of equity volatility is investigated by means of a multi-factor stochastic volatility model with time varying parameters. The parameters are estimated by means of a sequential matching procedure which adopts as auxiliary model a time-varying generalization of the HAR model f...

  6. Beyond leaf color: Comparing camera-based phenological metrics with leaf biochemical, biophysical, and spectral properties throughout the growing season of a temperate deciduous forest

    Science.gov (United States)

    Yang, Xi; Tang, Jianwu; Mustard, John F.

    2014-03-01

    Plant phenology, a sensitive indicator of climate change, influences vegetation-atmosphere interactions by changing the carbon and water cycles from local to global scales. Camera-based phenological observations of the color changes of the vegetation canopy throughout the growing season have become popular in recent years. However, the linkages between camera phenological metrics and leaf biochemical, biophysical, and spectral properties are elusive. We measured key leaf properties including chlorophyll concentration and leaf reflectance on a weekly basis from June to November 2011 in a white oak forest on the island of Martha's Vineyard, Massachusetts, USA. Concurrently, we used a digital camera to automatically acquire daily pictures of the tree canopies. We found that there was a mismatch between the camera-based phenological metric for the canopy greenness (green chromatic coordinate, gcc) and the total chlorophyll and carotenoids concentration and leaf mass per area during late spring/early summer. The seasonal peak of gcc is approximately 20 days earlier than the peak of the total chlorophyll concentration. During the fall, both canopy and leaf redness were significantly correlated with the vegetation index for anthocyanin concentration, opening a new window to quantify vegetation senescence remotely. Satellite- and camera-based vegetation indices agreed well, suggesting that camera-based observations can be used as the ground validation for satellites. Using the high-temporal resolution dataset of leaf biochemical, biophysical, and spectral properties, our results show the strengths and potential uncertainties to use canopy color as the proxy of ecosystem functioning.

  7. Green business will remain green

    International Nuclear Information System (INIS)

    Marcan, P.

    2008-01-01

    It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

  8. Green Power Partner Resources

    Science.gov (United States)

    EPA Green Power Partners can access tools and resources to help promote their green power commitments. Partners use these tools to communicate the benefits of their green power use to their customers, stakeholders, and the general public.

  9. Green Vehicle Guide

    Science.gov (United States)

    ... label Buy green. Save green. Learn about MPG math Discover fuel-saving tips Promote green ... U.S. consumers who have already purchased new vehicles under the fuel economy & greenhouse gas standard! More about the standards » Check ...

  10. Green Transformational Leadership and Green Performance: The Mediation Effects of Green Mindfulness and Green Self-Efficacy

    Directory of Open Access Journals (Sweden)

    Yu-Shan Chen

    2014-09-01

    Full Text Available No prior literature explores the influence of green transformational leadership on green performance, thus, this study develops a novel research framework to fill the research gap. This study investigates the influence of green transformational leadership on green performance and discusses the mediation effects of green mindfulness and green self-efficacy by means of structural equation modeling (SEM. The results indicate that green transformational leadership positively influences green mindfulness, green self-efficacy, and green performance. Moreover, this study demonstrates that the positive relationship between green transformational leadership and green performance is partially mediated by the two mediators: green mindfulness and green self-efficacy. It means that green transformational leadership can not only directly affect green performance positively but also indirectly affect it positively through green mindfulness and green self-efficacy. Therefore, firms need to raise their green transformational leadership, green mindfulness, and green self-efficacy to increase their green performance.

  11. Green Ocean Amazon 2014/15 Terrestrial Ecosystem Project (Geco) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, Kolby [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-06-01

    In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observational activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on

  12. Central Region Green Infrastructure

    Data.gov (United States)

    Minnesota Department of Natural Resources — This Green Infrastructure data is comprised of 3 similar ecological corridor data layers ? Metro Conservation Corridors, green infrastructure analysis in counties...

  13. Biological, medicinal and toxicological significance of Eucalyptus leaf essential oil: a review.

    Science.gov (United States)

    Dhakad, Ashok K; Pandey, Vijay V; Beg, Sobia; Rawat, Janhvi M; Singh, Avtar

    2018-02-01

    The genus Eucalyptus L'Heritier comprises about 900 species, of which more than 300 species contain volatile essential oil in their leaves. About 20 species, within these, have a high content of 1,8-cineole (more than 70%), commercially used for the production of essential oils in the pharmaceutical and cosmetic industries. However, Eucalyptus is extensively planted for pulp, plywood and solid wood production, but its leaf aromatic oil has astounding widespread biological activities, including antimicrobial, antiseptic, antioxidant, chemotherapeutic, respiratory and gastrointestinal disorder treatment, wound healing, and insecticidal/insect repellent, herbicidal, acaricidal, nematicidal, and perfumes, soap making and grease remover. In the present review, we have made an attempt to congregate the biological ingredients of leaf essential oil, leaf oil as a natural medicine, and pharmacological and toxicological values of the leaf oil of different Eucalyptus species worldwide. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  15. Fundamental volatility is regime specific

    NARCIS (Netherlands)

    Arnold, I.J.M.; MacDonald, R.; Vries, de C.G.

    2006-01-01

    A widely held notion holds that freely floating exchange rates are excessively volatile when judged against fundamentals and when moving from fixed to floating exchange rates. We re-examine the data and conclude that the disparity between the fundamentals and exchange rate volatility is more

  16. Development of a HS-SPME-GC/MS protocol assisted by chemometric tools to study herbivore-induced volatiles in Myrcia splendens.

    Science.gov (United States)

    Souza Silva, Érica A; Saboia, Giovanni; Jorge, Nina C; Hoffmann, Camila; Dos Santos Isaias, Rosy Mary; Soares, Geraldo L G; Zini, Claudia A

    2017-12-01

    A headspace solid phase microextraction (HS-SPME) method combined with gas chromatography-mass spectrometry (GC/MS) was developed and optimized for extraction and analysis of volatile organic compounds (VOC) of leaves and galls of Myrcia splendens. Through a process of optimization of main factors affecting HS-SPME efficiency, the coating divivnilbenzene-carboxen-polydimethylsiloxane (DVB/Car/PDMS) was chosen as the optimum extraction phase, not only in terms of extraction efficiency, but also for its broader analyte coverage. Optimum extraction temperature was 30°C, while an extraction time of 15min provided the best compromise between extraction efficiencies of lower and higher molecular weight compounds. The optimized protocol was demonstrated to be capable of sampling plant material with high reproducibility, considering that most classes of analytes met the 20% RSD FDA criterion. The optimized method was employed for the analysis of three classes of M. splendens samples, generating a final list of 65 tentatively identified VOC, including alcohols, aldehydes, esters, ketones, phenol derivatives, as well as mono and sesquiterpenes. Significant differences were evident amongst the volatile profiles obtained from non-galled leaves (NGL) and leaf-folding galls (LFG) of M. splendens. Several differences pertaining to amounts of alcohols and aldehydes were detected between samples, particularly regarding quantities of green leaf volatiles (GLV). Alcohols represented about 14% of compounds detected in gall samples, whereas in non-galled samples, alcohol content was below 5%. Phenolic derived compounds were virtually absent in reference samples, while in non-galled leaves and galls their content ranged around 0.2% and 0.4%, respectively. Likewise, methyl salicylate, a well-known signal of plant distress, amounted for 1.2% of the sample content of galls, whereas it was only present in trace levels in reference samples. Chemometric analysis based on Heatmap associated

  17. The green building envelope : Vertical greening

    NARCIS (Netherlands)

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve

  18. Volatile organic compounds

    International Nuclear Information System (INIS)

    Silseth, May Liss

    1998-01-01

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  19. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  20. Jakartans, Institutionally Volatile

    Directory of Open Access Journals (Sweden)

    Masaaki OKAMOTO

    2014-01-01

    Full Text Available Jakarta recently has gained even more central political attention in Indonesia since Joko Widodo (Jokowi and Basuki Purnama (Ahok became, respectively, the province’s governor and vice-governor in 2012. They started a series of eye-catching and populist programmes, drawing popular support from not only the people of Jakarta, but also among Indonesians in general. Jokowi is now even the most popular candidate for the presidential election in 2014. Their rise is phenomenal in this sense, but it is understandable if we look at Jakartan voters’ behaviour and the institutional arrangement that leads to it. Jakarta, as the national capital, has a unique arrangement in that the province has no autonomous regency or city. This paper argues that this arrangement causes Jakartans to be more politically volatile and describes how this institutional arrangement was created by analysing the minutes of the meeting to discuss the laws concerning Jakarta Province.

  1. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  2. Terpenes of Salvia species leaf oils: chemosystematic implications

    OpenAIRE

    Coassini Lokar, Laura; Moneghini, Mariarosa

    2017-01-01

    Wild specimens of Salvia L. were collected in three different moments of anthesis and their volatile leaf oils were analyzed by GC/GCMS. The quantitative terpene composition is very variable with the anthesis. S. bertolonii is the richest species in a-thujone. S. officinalis is characterized by high percentages of 1,8 cineole, 4-terpineol, isorboneol and a -bisabolol. In S. verticillata high percentages of borneol and {3-cariophyllene are present. In the three species a-thujone was always mor...

  3. How Green is 'Green' Energy?

    Science.gov (United States)

    Gibson, Luke; Wilman, Elspeth N; Laurance, William F

    2017-12-01

    Renewable energy is an important piece of the puzzle in meeting growing energy demands and mitigating climate change, but the potentially adverse effects of such technologies are often overlooked. Given that climate and ecology are inextricably linked, assessing the effects of energy technologies requires one to consider their full suite of global environmental concerns. We review here the ecological impacts of three major types of renewable energy - hydro, solar, and wind energy - and highlight some strategies for mitigating their negative effects. All three types can have significant environmental consequences in certain contexts. Wind power has the fewest and most easily mitigated impacts; solar energy is comparably benign if designed and managed carefully. Hydropower clearly has the greatest risks, particularly in certain ecological and geographical settings. More research is needed to assess the environmental impacts of these 'green' energy technologies, given that all are rapidly expanding globally. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Nonparametric methods for volatility density estimation

    NARCIS (Netherlands)

    Es, van Bert; Spreij, P.J.C.; Zanten, van J.H.

    2009-01-01

    Stochastic volatility modelling of financial processes has become increasingly popular. The proposed models usually contain a stationary volatility process. We will motivate and review several nonparametric methods for estimation of the density of the volatility process. Both models based on

  5. Long-distance signaling within Coleus x hybridus leaves; mediated by changes in intra-leaf CO2?

    Science.gov (United States)

    Stahlberg, R.; Van Volkenburgh, E.; Cleland, R. E.

    2001-01-01

    Rapid long-distance signaling in plants can occur via several mechanisms, including symplastic electric coupling and pressure waves. We show here in variegated Coleus leaves a rapid propagation of electrical signals that appears to be caused by changes in intra-leaf CO2 concentrations. Green leaf cells, when illuminated, undergo a rapid depolarization of their membrane potential (Vm) and an increase in their apoplastic pH (pHa) by a process that requires photosynthesis. This is followed by a slower hyperpolarization of Vm and apoplastic acidification, which do not require photosynthesis. White (chlorophyll-lacking) leaf cells, when in isolated white leaf segments, show only the slow response, but when in mixed (i.e. green and white) segments, the rapid Vm depolarization and increase in pHa propagate over more than 10 mm from the green to the white cells. Similarly, these responses propagate 12-20 mm from illuminated to unilluminated green cells. The fact that the propagation of these responses is eliminated when the leaf air spaces are infiltrated with solution indicates that the signal moves in the apoplast rather than the symplast. A depolarization of the mesophyll cells is induced in the dark by a decrease in apoplastic CO2 but not by an increase in pHa. These results support the hypothesis that the propagating signal for the depolarization of the white mesophyll cells is a photosynthetically induced decrease in the CO2 level of the air spaces throughout the leaf.

  6. 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.

  7. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2008-01-01

    This paper examines the advantages of incorporating strategic exposure to equity volatility into the investment-opportunity set of a long-term equity investor. We consider two standard volatility investments: implied volatility and volatility risk premium strategies. To calibrate and assess the risk/return profile of the portfolio, we present an analytical framework offering pragmatic solutions for long-term investors seeking exposure to volatility. The benefit of volatility exposure for a co...

  8. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  9. Parallel Prediction of Stock Volatility

    Directory of Open Access Journals (Sweden)

    Priscilla Jenq

    2017-10-01

    Full Text Available Volatility is a measurement of the risk of financial products. A stock will hit new highs and lows over time and if these highs and lows fluctuate wildly, then it is considered a high volatile stock. Such a stock is considered riskier than a stock whose volatility is low. Although highly volatile stocks are riskier, the returns that they generate for investors can be quite high. Of course, with a riskier stock also comes the chance of losing money and yielding negative returns. In this project, we will use historic stock data to help us forecast volatility. Since the financial industry usually uses S&P 500 as the indicator of the market, we will use S&P 500 as a benchmark to compute the risk. We will also use artificial neural networks as a tool to predict volatilities for a specific time frame that will be set when we configure this neural network. There have been reports that neural networks with different numbers of layers and different numbers of hidden nodes may generate varying results. In fact, we may be able to find the best configuration of a neural network to compute volatilities. We will implement this system using the parallel approach. The system can be used as a tool for investors to allocating and hedging assets.

  10. Low-temperature process steps for realization of non-volatile memory devices

    NARCIS (Netherlands)

    Brunets, I.; Boogaard, A.; Aarnink, Antonius A.I.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.; Holleman, J.; Schmitz, Jurriaan

    2007-01-01

    In this work, the low-temperature process steps required for the realization of nano-crystal non-volatile memory cells are discussed. An amorphous silicon film, crystallized using a diode pumped solid state green laser irradiating at 532 nm, is proposed as an active layer. The deposition of the

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

    Science.gov (United States)

    Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

    2016-05-01

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

  12. Volatile Constituents of Three Piper Species from Vietnam.

    Science.gov (United States)

    Hieua, Le D; Hoic, Tran M; Thangda, Tran D; Ogunwande, Isiaka A

    2015-11-01

    The chemical compositions of the essential oils obtained by hydrodistillation of three Piper plants grown in Vietnam are reported. The analysis was achieved by means of gas chromatography with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main constituents of the leaf oil of Piper majusculum Blume were β-caryophyllene (20.7%), germacrene D (18.6%) and β-elemene (11.3%). The quantitatively significant compounds of the volatile oils of P. harmandii C. DC were sabinene (leaves, 14.5%; stems, 16.2%), benzyl benzoate (leaves, 20.0%; stems, 29.40%) and benzyl salicylate (leaves, 14.1%; stems, 24.3%). Also, α-cadinol (17.0%) was identified in large proportion in the leaf oil. However, sabinene (leaves, 17.9%; stems, 13.5%), benzyl benzoate (leaves, 20.5%; stems, 32.5%) and β-eudesmol (leaves, 13.8%; stems, 8.4%) were the main constituents of P. brevicaule C. DC. This is the first report on the volatile constituents of both P. harmandii and P. brevicaule.

  13. Leaf chemical composition of twenty-one Populus hybrid clones grown under intensive culture

    Science.gov (United States)

    Richard E. Dickson; Philip R. Larson

    1976-01-01

    Leaf material from 21 nursery-grown Populus hybrid clones was analyzed for three nitrogen fractions (total N, soluble protein, and soluble amino acids) and three carbhydrate fractions (reducing sugars, total soluble sugars, and total nonstructural carbohydrates-TNC). In addition, nursery-grown green ash and silver maple, field-grown bigtooth and trembling aspen, and...

  14. Volatiles in the Martian regolith

    International Nuclear Information System (INIS)

    Clark, B.C.; Baird, A.K.

    1979-01-01

    An inventory of released volatiles on Mars has been derived based upon Viking measurements of atmospheric and surface chemical composition, and upon the inferred mineralogy of a ubiquitous regolith, assumed to average 200m in depth. This model is consistent with the relative abundances of volatiles (except for S) on the Earth's surface, but implies one-fifteenth of the volatile release of Earth if starting materials were comparable. All constituents are accommodated as chemical components of, or absorbed phases on, regolith materials--without the necessity of invoking unobservable deposits of carbonates, nitrates, or permafrost ice

  15. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable....

  16. The leaf angle distribution of natural plant populations: assessing the canopy with a novel software tool.

    Science.gov (United States)

    Müller-Linow, Mark; Pinto-Espinosa, Francisco; Scharr, Hanno; Rascher, Uwe

    2015-01-01

    Three-dimensional canopies form complex architectures with temporally and spatially changing leaf orientations. Variations in canopy structure are linked to canopy function and they occur within the scope of genetic variability as well as a reaction to environmental factors like light, water and nutrient supply, and stress. An important key measure to characterize these structural properties is the leaf angle distribution, which in turn requires knowledge on the 3-dimensional single leaf surface. Despite a large number of 3-d sensors and methods only a few systems are applicable for fast and routine measurements in plants and natural canopies. A suitable approach is stereo imaging, which combines depth and color information that allows for easy segmentation of green leaf material and the extraction of plant traits, such as leaf angle distribution. We developed a software package, which provides tools for the quantification of leaf surface properties within natural canopies via 3-d reconstruction from stereo images. Our approach includes a semi-automatic selection process of single leaves and different modes of surface characterization via polygon smoothing or surface model fitting. Based on the resulting surface meshes leaf angle statistics are computed on the whole-leaf level or from local derivations. We include a case study to demonstrate the functionality of our software. 48 images of small sugar beet populations (4 varieties) have been analyzed on the base of their leaf angle distribution in order to investigate seasonal, genotypic and fertilization effects on leaf angle distributions. We could show that leaf angle distributions change during the course of the season with all varieties having a comparable development. Additionally, different varieties had different leaf angle orientation that could be separated in principle component analysis. In contrast nitrogen treatment had no effect on leaf angles. We show that a stereo imaging setup together with the

  17. Unfolding Green Defense

    DEFF Research Database (Denmark)

    Larsen, Kristian Knus

    2015-01-01

    In recent years, many states have developed and implemented green solutions for defense. Building on these initiatives NATO formulated the NATO Green Defence Framework in 2014. The framework provides a broad basis for cooperation within the Alliance on green solutions for defense. This report aims...... to inform and support the further development of green solutions by unfolding how green technologies and green strategies have been developed and used to handle current security challenges. The report, initially, focuses on the security challenges that are being linked to green defense, namely fuel...... consumption in military operations, defense expenditure, energy security, and global climate change. The report then proceeds to introduce the NATO Green Defence Framework before exploring specific current uses of green technologies and green strategies for defense. The report concludes that a number...

  18. An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

    Science.gov (United States)

    Beck, John J; Smith, Lincoln; Baig, Nausheena

    2014-01-01

    The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Green industrial policy

    OpenAIRE

    Dani Rodrik

    2014-01-01

    Green growth requires green technologies: production techniques that economize on exhaustible resources and emit fewer greenhouse gases. The availability of green technologies both lowers social costs in the transition to a green growth path and helps achieve a satisfactory rate of material progress under that path. The theoretical case in favour of using industrial policy to facilitate green growth is quite strong. Economists’ traditional scepticism on industrial policy is grounded instead o...

  20. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  1. Serrated leaf mutant in mungbean (Vigna radiata (L) Wilczek)

    International Nuclear Information System (INIS)

    Malik, I.A.; Ghulam, Sarwar; Yousaf, Ali; Saleem, M.

    1988-01-01

    Dry dormant seeds of mungbean (Vigna radiata (L) Wilczek) were treated with gamma rays (15, 30 and 60 kR). The serrated leaf mutation was noticed in M 2 of cultivar Pak 32 treated with 60 kR. Cf 14 plants, 3 showed the altered leaf structure and the others were normal. The feature of this mutant was the deep serration of leaflet margins. The mutant had large thick leaflets with prominent venation. The mutant bred true in the M 3 and successive generation. Details of the morphological characteristics of the mutant are presented. The mutant exhibited slower growth particularly during the early stages of development, flowered later and attained shorter height. There was an increase in the number of pods, in seed weight and in seed protein content, but number of seed per pod was considerably reduced. The seed coat colour showed a change from green to yellowish green. In the mutant's flowers the stamina were placed much below the stigma level and the stigma sometimes protruded the corolla. Outcrossing of 4% recorded in some of the mutant lines revealed a reduced cleistogamy. The low number of seeds per pod in the mutant could be due to reduced pollen fertility. The mutant behaved as monogenic recessive. The symbols SL/sl are proposed for this allelic pair. The mutant may have use as a green manure crop because of its large foliage and for the breeders as a genetic marker

  2. Molecular Basis Underlying Leaf Variegation of a Moth Orchid Mutant (Phalaenopsis aphrodite subsp. formosana

    Directory of Open Access Journals (Sweden)

    Chi-Chu Tsai

    2017-07-01

    Full Text Available Leaf variegation is often the focus of plant breeding. Here, we studied a variegated mutant of Phalaenopsis aphrodite subsp. formosana, which is usually used as a parent of horticultural breeding, to understand its anatomic and genetic regulatory mechanisms in variegation. Chloroplasts with well-organized thylakoids and starch grains were found only in the mesophyll cells of green sectors but not of yellow sectors, confirming that the variegation belongs to the chlorophyll type. The two-dimensional electrophoresis and LC/MS/MS also reveal differential expressions of PsbP and PsbO between the green and yellow leaf sectors. Full-length cDNA sequencing revealed that mutant transcripts were caused by intron retention. When conditioning on the total RNA expression, we found that the functional transcript of PsbO and mutant transcript of PsbP are higher expressed in the yellow sector than in the green sector, suggesting that the post-transcriptional regulation of PsbO and PsbP differentiates the performance between green and yellow sectors. Because PsbP plays an important role in the stability of thylakoid folding, we suggest that the negative regulation of PsbP may inhibit thylakoid development in the yellow sectors. This causes chlorophyll deficiency in the yellow sectors and results in leaf variegation. We also provide evidence of the link of virus CymMV and the formation of variegation according to the differential expression of CymMV between green and yellow sectors.

  3. 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 ...

  4. Secretory cavities and volatiles of Myrrhinium atropurpureum Schott var. atropurpureum (Myrtaceae): an endemic species collected in the restingas of Rio de Janeiro, Brazil.

    Science.gov (United States)

    Victório, Cristiane Pimentel; Moreira, Claudio B; Souza, Marcelo da Costa; Sato, Alice; Arruda, Rosani do Carmo de Oliveira

    2011-07-01

    In this study, we investigated the leaf anatomy and the composition of volatiles in Myrrhinium atropurpureum var. atropurpureum endemic to Rio de Janeiro restingas. Particularly, leaf secretory structures were described using light microscopy, and histochemical tests were performed from fresh leaves to localize the secondary metabolites. To observe secretory cavities, fixed leaf samples were free-hand sectioned. To evaluate lipophilic compounds and terpenoids the following reagents were employed: Sudans III and IV, Red oil O and Nile blue. Leaf volatiles were characterized by gas chromatography after hydrodistillation (HD) or simultaneous distillation-extraction (SDE). Leaf analysis showed several cavities in mesophyll that are the main sites of lipophilic and terpenoid production. Monoterpenes, which represented more than 80% of the major volatiles, were characterized mainly by alpha- and beta-pinene and 1,8-cineole. In order to provide tools for M. atropurpureum identification, the following distinguishing characteristics were revealed by the following data: 1) adaxial face clear and densely punctuated by the presence of round or ellipsoidal secretory cavities randomly distributed in the mesophyll; 2) the presence of cells overlying the upper neck cells of secretory cavities; 3) the presence of numerous paracytic stomata distributed on the abaxial leaf surface, but absent in vein regions and leaf margin; and 4) non-glandular trichomes on both leaf surfaces. Our study of the compounds produced by the secretory cavities of M. atropurpureum led us to conclude that volatile terpenoid class are the main secretory compounds and that they consist of a high concentration of monoterpenes, which may indicate the phytotherapeutic importance of this plant.

  5. Green corridors basics

    DEFF Research Database (Denmark)

    Panagakos, George

    2016-01-01

    SuperGreen project, which aimed at advancing the green corridor concept through a benchmarking exercise involving Key Performance Indicators (KPIs). The chapter discusses the available definitions of green corridors and identifies the characteristics that distinguish a green corridor from any other...... efficient surface transportation corridor. After providing examples of green corridor projects in Europe, it focuses on the KPIs that have been proposed by various projects for monitoring the performance of a freight corridor. Emphasis is given to the SuperGreen KPIs, covering the economic, technical...

  6. 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.

  7. Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma.

    Science.gov (United States)

    Zeng, Lanting; Zhou, Ying; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Gui, Jiadong; Dong, Fang; Tang, Jinchi; Ma, Shengzhou; Yang, Ziyin

    2017-12-15

    The raw materials used to make oolong tea (Camellia sinensis) are a combination of leaf and stem. Oolong tea made from leaf and stem is thought to have a more aromatic smell than leaf-only tea. However, there is no available evidence to support the viewpoint. In this study, sensory evaluation and detailed characterization of emitted and internal volatiles (not readily emitted, but stored in samples) of dry oolong teas and infusions indicated that the presence of stem did not significantly improve the total aroma characteristics. During the enzyme-active processes, volatile monoterpenes and theanine were accumulated more abundantly in stem than in leaf, while jasmine lactone, indole, and trans-nerolidol were lower in stem than in leaf. Tissue-specific aroma-related gene expression and availability of precursors of aroma compounds resulted in different aroma distributions in leaf and stem. This study presents the first determination of the contribution of stem to oolong tea aroma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Evaluation of volatiles from Ampelopsis brevipedunculata var. heterophylla using GC-olfactometry, GC-MS and GC-pulsed flame photometric detector.

    Science.gov (United States)

    Nakamura, Atsuhiko; Miyazawa, Mitsuo

    2013-01-01

    Ampelopsis brevipedunculata var. heterophylla is extensively cultivated in Asia, and the dried leaves and branches have a characteristic odor and have been used as a tea. To investigate the odorants contributing to the characteristic odor of A. brevipedunculata var. heterophylla, the aroma extraction dilution analysis method was performed through gas chromatography olfactometry. In addition, volatile sulfur compounds were evaluated using pulsed flame photometric detector. As a result, 86 compounds were identified in the oils of leaves and 78 in branches, accounting for 80.0% and 68.3%, respectively, of the compounds identified. The main compounds in the essential oil of leaves were palmitic acid (12.5%), phenylacetaldehyde (4.1%) and hexahydrofarnesyl acetone (3.9%). On the other hand, the essential oil of branches contained palmitic acid (12.7%), terpinen-4-ol (4.4%) and α-cadinol (3.7%). The total number of odor-active compounds identified in the leaf and branch oils was 39. The most odorous compounds of leaves and branches of A. brevipedunculata var. heterophylla were (E, Z)-2,6-nonadienal (melon, green odor), (E)-2-nonenal (grassy odor), phenylacetaldehyde (honey-like) and (E)-linalool oxide (woody odor).

  9. Chemical and mechanical changes during leaf expansion of four woody species of dry Restinga woodland.

    Science.gov (United States)

    Schlindwein, C C D; Fett-Neto, A G; Dillenburg, L R

    2006-07-01

    Young leaves are preferential targets for herbivores, and plants have developed different strategies to protect them. This study aimed to evaluate different leaf attributes of presumed relevance in protection against herbivory in four woody species (Erythroxylum argentinum, Lithrea brasiliensis, Myrciaria cuspidata, and Myrsine umbellata), growing in a dry restinga woodland in southern Brazil. Evaluation of leaf parameters was made through single-point sampling of leaves (leaf mass per area and leaf contents of nitrogen, carbon, and pigments) at three developmental stages and through time-course sampling of expanding leaves (area and strength). Leaves of M. umbellata showed the highest leaf mass per area (LMA), the largest area, and the longest expansion period. On the other extreme, Myrc. cuspidata had the smallest LMA and leaf size, and the shortest expansion period. Similarly to L. brasiliensis, it displayed red young leaves. None of the species showed delayed-greening, which might be related to the high-irradiance growth conditions. Nitrogen contents reduced with leaf maturity and reached the highest values in the young leaves of E. argentinum and Myrc. cuspidata and the lowest in M. umbellata. Each species seems to present a different set of protective attributes during leaf expansion. Myrciaria cuspidata appears to rely mostly on chemical defences to protect its soft leaves, and anthocyanins might play this role at leaf youth, while M. umbellata seems to invest more on mechanical defences, even at early stages of leaf growth, as well as on a low allocation of nitrogen to the leaves. The other species display intermediate characteristics.

  10. Calcium oxalate druses affect leaf optical properties in selenium-treated Fagopyrum tataricum.

    Science.gov (United States)

    Golob, Aleksandra; Stibilj, Vekoslava; Nečemer, Marijan; Kump, Peter; Kreft, Ivan; Hočevar, Anja; Gaberščik, Alenka; Germ, Mateja

    2018-03-01

    Plants of the genus Fagopyrum contain high levels of crystalline calcium oxalate (CaOx) deposits, or druses, that can affect the leaf optical properties. As selenium has been shown to modify the uptake and accumulation of metabolically important elements such as calcium, we hypothesised that the numbers of druses can be altered by selenium treatment, and this would affect the leaf optical properties. Tartary buckwheat (Fagopyrum tataricum Gaertn.) was grown outdoors in an experimental field. At the beginning of flowering, plants were foliarly sprayed with sodium selenate solution at 10 mg selenium L -1 or only with water. Plant morphological, biochemical, physiological and optical properties were examined, along with leaf elemental composition and content. Se spraying did not affect leaf biochemical and functional properties. However, it increased leaf thickness and the contents of Se in the leaves, and decreased the density of calcium oxalate druses in the leaves. Except Se content, Se spraying did not affect contents of other elements in leaves, including total calcium per dry mass of leaf tissue. Redundancy analysis showed that of all parameters tested, only the calcium oxalate druses parameters were significant in explaining the variability of the leaf reflectance and transmittance spectra. The density of CaOx druses positively correlated with the reflectance in the blue, green, yellow and UV-B regions of the spectrum, while the area of CaOx druses per mm 2 of leaf transection area positively correlated with the transmittance in the green and yellow regions of the spectrum. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect

    Directory of Open Access Journals (Sweden)

    Kouki Fujioka

    2016-04-01

    Full Text Available For serving green tea, there are two prominent methods: steeping the leaf or the powdered leaf (matcha style in hot water. The purpose of the present study was to reveal chemical and functional differences before and after the powdering process of green tea leaf, since powdered green tea may contribute to expanding the functionality because of the different ingesting style. In this study, we revealed that the powdering process with a ceramic mill and stirring in hot water increased the average extracted concentration of epigallocatechin gallate (EGCG by more than three times compared with that in leaf tea using high-performance liquid chromatography (HPLC and liquid chromatography–tandem mass Spectrometry (LC-MS/MS analyses. Moreover, powdered green tea has a higher inhibition effect of reactive oxygen species (ROS production in vitro compared with the same amount of leaf tea. Our data suggest that powdered green tea might have a different function from leaf tea due to the higher catechin contents and particles.

  12. Volatility Properties of Polonium

    International Nuclear Information System (INIS)

    Eichler, B.

    2002-06-01

    Thermodynamical constants to describe evaporation processes of polonium are summarized and critically discussed. Additionally, systematic changes of the properties of the chalcogenes are analyzed, empirical correlations are proofed and cyclic processes are balanced. Accordingly, the existing values of entropies for polonium are acceptable. Questionable, however, are those values of enthalpies, which have been deduced from results of the experimental investigations of the vapor pressure temperature dependency, of the melting point, and of the boiling temperatures. Technical difficulties and possible error sources of the measurements resulting from the radioactive decay properties of 210 Po are discussed. Using extrapolative standard enthalpies and entropies as well as their temperature dependency, the equilibrium partial pressure of the monomeric and dimeric polonium above the pure condensed phase and the equilibrium constant of the dimerization reaction in the gas phase are calculated: log p/pa Po (g) = (11.797 ± 0.024) -(9883.4 ± 9.5)/T (for T = 298-600 K); = (10.661 ± 0.057) - (9328.4 ± 4.9)/T (for T = 500-1300 K); log p/pa Po 2 (g) = (13.698 ± 0.049) - (8592.3 ± 19.6)/T (for T = 298-600 K); = (11.424 ± 0.124) - (7584.1 ± 98.1)/T (for T = 500-1300 K); log K (dim) = (-4.895 ± 0.012) + (11071 ± 6)/T. According to these calculations and in contrast to other works, polonium evaporates in the entire temperature range between 298 and 1300 K in the dimeric state. Hence, 'latent heats' of the volatilization processes are clearly larger compared to literature data. Especially in the temperature range of the solid polonium the calculated vapor pressure curve shifts significantly to lower values, whereas the boiling point was almost reproduced by the calculation. The results of the extrapolation for the standard enthalpy of the gaseous monomeric polonium and the dimerization enthalpy ΔH 0 298 Po (g) = 188.9 kJ/mol and ΔH 0 298 (form) Po 2 (g) = 211.5 kJ/mol are

  13. [Study on spectral detection of green plant target].

    Science.gov (United States)

    Deng, Wei; Zhao, Chun-jiang; He, Xiong-kui; Chen, Li-ping; Zhang, Lu-da; Wu, Guang-wei; Mueller, J; Zhai, Chang-yuan

    2010-08-01

    Weeds grow scatteredly in fields, where many insentient objects exist, for example, withered grasses, dry twig and barriers. In order to improve the precision level of spraying, it is important to study green plant detecting technology. The present paper discussed detecting method of green plant by using spectral recognizing technology, because of the real-time feature of spectral recognition. By analyzing the reflectivity difference between each of the two sides of the "red edge" of the spectrum from plants and surrounding environment, green plant discriminat index (GPDI) is defined as the value which equals the reflectivity ratio at the wavelength of 850 nm divided by the reflectivity ratio at the wavelength of 650 nm. The original spectral data of green plants and the background were measured by using the handhold FieldSpec 3 Spectroradiometer manufactured by ASD Inc. in USA. The spectral data were processed to get the reflectivity of each measured objects and to work out the GPDI thereof as well. The classification model of green plant and its background was built up using decision tree method in order to obtain the threshold of GPDI to distinguish green plants and the background. The threshold of GPDI was chosen as 5.54. The detected object was recognized as green plant when it is GPDI>GPDITH, and vice versa. Through another test, the accuracy rate was verified which was 100% by using the threshold. The authors designed and developed the green plant detector based on single chip microcomputer (SCM) "AT89S51" and photodiode "OPT101" to realize detecting green plants from the background. After passing through two optical filters, the center wavelengths of which are 650 and 850 nm respectively, the reflected light from measured targets was detected by two photodiodes and converted into electrical signals. These analog signals were then converted to digital signals via an analog-to-digital converter (ADS7813) after being amplified by a signal amplifier (OP400

  14. 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

  15. Green Power Partnership 100 Green Power Users

    Science.gov (United States)

    EPA's Green Power Partnership is a voluntary program designed to reduce the environmental impact of electricity generation by promoting renewable energy. Partners on this list use green power to meet 100 of their U.S. organization-wide electricity use.

  16. Urban Greening Bay Area

    Science.gov (United States)

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  17. Tribal Green Building Toolkit

    Science.gov (United States)

    This Tribal Green Building Toolkit (Toolkit) is designed to help tribal officials, community members, planners, developers, and architects develop and adopt building codes to support green building practices. Anyone can use this toolkit!

  18. Green Power Partner List

    Science.gov (United States)

    The U.S. EPA's Green Power Partnership is a voluntary program designed to reduce the environmental impact of electricity generation by promoting renewable energy. There are thousands of Green Power Partners, all listed on this page.

  19. Green Power Communities

    Science.gov (United States)

    GPCs are towns, villages, cities, counties, or tribal governments in which the local government, businesses, and residents collectively use green power in amounts that meet or exceed EPA's Green Power Community purchase requirements.

  20. Blue-Green Algae

    Science.gov (United States)

    ... that taking a specific blue-green algae product (Super Blue-Green Algae, Cell Tech, Klamath Falls, OR) ... system. Premenstrual syndrome (PMS). Depression. Digestion. Heart disease. Memory. Wound healing. Other conditions. More evidence is needed ...

  1. Green Bank Observatory (GBO)

    Data.gov (United States)

    Federal Laboratory Consortium — The largest fully steerable telescope in the world - the Robert C. Byrd Green Bank Telescope (GBT), began observations in Green Bank, West Virginia in 2000and is a...

  2. Green Infrastructure Modeling Toolkit

    Science.gov (United States)

    Green infrastructure, such as rain gardens, green roofs, porous pavement, cisterns, and constructed wetlands, is becoming an increasingly attractive way to recharge aquifers and reduce the amount of stormwater runoff that flows into wastewater treatment plants or into waterbodies...

  3. Tracing the link between plant volatile organic compound emissions and CO2 fluxes and by stable isotopes

    Science.gov (United States)

    Werner, Christiane; Wegener, Frederik; Jardine, Kolby

    2015-04-01

    The vegetation exerts a large influence on the atmosphere through the emission of volatile organic compounds (VOCs) and the emission and uptake of the greenhouse gas CO2. Despite the enormous importance, processes controlling plant carbon allocation into primary and secondary metabolism, such as photosynthetic carbon uptake, respiratory CO2 emission and VOC synthesis, remains unclear. Moreover, vegetation-atmosphere CO2 exchange is associated with a large isotopic imprint due to photosynthetic carbon isotope discrimination and 13C-fractionation during respiratory CO2 release1. The latter has been proposed to be related to carbon partitioning in the metabolic branching points of the respiratory pathways and secondary metabolism, which are linked via a number of interfaces including the central metabolite pyruvate. Notably, it is a known substrate in a large array of secondary pathways leading to the biosynthesis of many volatile organic compounds (VOCs), such as volatile isoprenoids, oxygenated VOCs, aromatics, fatty acid oxidation products, which can be emitted by plants. Here we investigate the linkage between VOC emissions, CO2 fluxes and associated isotope effects based on simultaneous real-time measurements of stable carbon isotope composition of branch respired CO2 (CRDS) and VOC fluxes (PTR-MS). We utilized positionally specific 13C-labeled pyruvate branch feeding experiments in the mediterranean shrub (Halimium halimifolium) to trace the partitioning of C1, C2, and C3 carbon atoms of pyruvate into VOCs versus CO2 emissions in the light and in the dark. In the light, we found high emission rates of a large array of VOC including volatile isoprenoids, oxygenated VOCs, green leaf volatiles, aromatics, sulfides, and nitrogen containing VOCs. These observations suggest that in the light, H. halimifolium dedicates a high carbon flux through secondary biosynthetic pathways including the pyruvate dehydrogenase bypass, mevalonic acid, MEP/DOXP, shikimic acid, and

  4. Volatilization of iodine from vegetation

    International Nuclear Information System (INIS)

    Amiro, B.D.; Johnston, F.L.

    1989-01-01

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na 125 I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author)

  5. Distribution Characterization of Leaf and Hull Pubescences and Genetic Analysis of Their Numbers in japonica Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Xiao-biao ZHU

    2008-12-01

    Full Text Available Distributions of pubescences on leaf blade and hull in japonica rice were observed under an optical microscope. Numbers of leaf and hull pubescences in P1, P2, F1, B1, B2 and F2 generations were investigated in three combinations of japonica rice (Sidao 10A/Wuyujing 3R, Wuyujing 3A/Sidao 10R and Liuyan 189A/HR-122, and genetic analysis for these two traits were conducted by using the joint analysis method of P1, P2, F1, B1, B2 and F2 generations with the mixed major gene plus polygene inheritance models. Leaf pubescences characterized by swollen base and fine tip distributed regularly on the boundary between dark green stripe and light green stripe of leaf blade. Hull pubescences with various lengths distributed irregularly on the whole hull. Numbers of leaf pubescences in the reciprocal combinations of Sidao 10A/Wuyujing 3R and Wuyujing 3A/Sidao 10R and numbers of hull pubescences in all the three combinations were controlled by one pair of additive major genes plus additive-dominant polygenes. In the combination of Liuyan 189A/HR-122, number of leaf pubescences was controlled by one pair of additive-dominant major genes plus additive-dominant polygenes. Both numbers of leaf and hull pubescences were mainly governed by major genes.

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

  7. 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...

  8. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    OpenAIRE

    Chen, Jinghui; Kobayashi, Masahito; McAleer, Michael

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The proposed test is a stochastic volatility version of the co-movement test proposed by Engle and Susmel (1993), who investigated whether international equity markets have volatility co-movement using t...

  9. Green Antibiotic Daun Sirih (Piper betle l.) Sebagai Pengganti Antibiotik Komersial untuk Penanganan Mastitis

    OpenAIRE

    Gabby Lutviandhitarani; Dian Wahyu Harjanti; Fajar Wahyono

    2015-01-01

    (Green antibiotic betel leaf (Piper betle l.) as a substitute  for commercial antibiotic in mastitis treatment)  ABSTRACT. The present study was carried out to investigate the possible antibacterial activity of betel leaf on the amount and microscopic appearance of mastitis-causing bacteria. The randomized block design with 5 treatment groups were : K group (mastitis milk only as negative control), Ab group (mastitis milk + antibiotic penicillin-dihydrostreptomycin as positive control),  ...

  10. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  11. Show Me the Green

    Science.gov (United States)

    Norbury, Keith

    2013-01-01

    Gone are the days when green campus initiatives were a balm to the soul and a drain on the wallet. Today's environmental initiatives are all about saving lots of green--in every sense of the word. The environmental benefits of green campus projects--whether wind turbines or better insulation--are pretty clear. Unfortunately, in today's…

  12. Green roof Malta

    OpenAIRE

    Gatt, Antoine

    2015-01-01

    In Malta, buildings cover one third of the Island, leaving greenery in the dirt track. Green roofs are one way to bring plants back to urban areas with loads of benefits. Antoine Gatt, who manages the LifeMedGreenRoof project at the University of Malta, tells us more. http://www.um.edu.mt/think/green-roof-malta/

  13. EPA's Green Roof Research

    Science.gov (United States)

    This is a presentation on the basics of green roof technology. The presentation highlights some of the recent ORD research projects on green roofs and provices insight for the end user as to the benefits for green roof technology. It provides links to currently available EPA re...

  14. In the Green

    Science.gov (United States)

    Kennedy, Mike

    2011-01-01

    Education officials used to debate whether they could afford to pursue green design and construction. Now the green movement has gained a foothold not just in education, but in society at large, and the prevailing attitude seems to have shifted. Can schools afford "not" to go green? As budgets are slashed repeatedly, education administrators must…

  15. The green agenda

    CERN Document Server

    Calder, Alan

    2009-01-01

    This business guide to Green IT was written to introduce, to a business audience, the opposing groups and the key climate change concepts, to provide an overview of a Green IT strategy and to set out a straightforward, bottom line-orientated Green IT action plan.

  16. The Green Man

    Science.gov (United States)

    Watson-Newlin, Karen

    2010-01-01

    The Jolly Green Giant. Robin Hood. The Bamberg Cathedral. Tales of King Arthur. Ecology. What do they have in common? What legends and ancient myths are shrouded in the tales of the Green Man? Most often perceived as an ancient Celtic symbol as the god of spring and summer, the Green Man disappears and returns year after year, century after…

  17. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  18. Multiscaling and clustering of volatility

    Science.gov (United States)

    Pasquini, Michele; Serva, Maurizio

    1999-07-01

    The dynamics of prices in stock markets has been studied intensively both experimentally (data analysis) and theoretically (models). Nevertheless, while the distribution of returns of the most important indices is known to be a truncated Lévy, the behaviour of volatility correlations is still poorly understood. What is well known is that absolute returns have memory on a long time range, this phenomenon is known in financial literature as clustering of volatility. In this paper we show that volatility correlations are power laws with a non-unique scaling exponent. This kind of multiscale phenomenology is known to be relevant in fully developed turbulence and in disordered systems and it is pointed out here for the first time for a financial series. In our study we consider the New York Stock Exchange (NYSE) daily index, from January 1966 to June 1998, for a total of 8180 working days.

  19. Green Transformational Leadership and Green Performance: The Mediation Effects of Green Mindfulness and Green Self-Efficacy

    OpenAIRE

    Yu-Shan Chen; Ching-Hsun Chang; Yu-Hsien Lin

    2014-01-01

    No prior literature explores the influence of green transformational leadership on green performance, thus, this study develops a novel research framework to fill the research gap. This study investigates the influence of green transformational leadership on green performance and discusses the mediation effects of green mindfulness and green self-efficacy by means of structural equation modeling (SEM). The results indicate that green transformational leadership positively influences green min...

  20. Relationships between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches.

    Science.gov (United States)

    Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S

    2016-01-15

    The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015

  1. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  2. Green Thunderstorms Observed.

    Science.gov (United States)

    Gallagher, Frank W., III; Beasley, William H.; Bohren, Craig F.

    1996-12-01

    Green thunderstorms have been observed from time to time in association with deep convection or severe weather events. Often the green coloration has been attributed to hail or to reflections of light from green foliage on the ground. Some skeptics who have not personally observed a green thunderstorm do not believe that green thunderstorms exist. They suggest that the green storms may be fabrications by excited observers. The authors have demonstrated the existence of green thunderstorms objectively using a spectrophotometer. During the spring and summer of 1995 the authors observed numerous storms and recorded hundreds of spectra of the light emanating corn these storms. It was found that the subjective judgment of colors can vary somewhat between observers, but the variation is usually in the shade of green. The authors recorded spectra of green and nongreen thunderstorms and recorded spectral measurements as a storm changed its appearance from dark blue to a bluish green. The change in color is gradual when observed from a stationary position. Also, as the light from a storm becomes greener, the luminance decreases. The authors also observed and recorded the spectrum of a thunderstorm during a period of several hours as they flew in an aircraft close to a supercell that appeared somewhat green. The authors' observations refute the ground reflection hypothesis and raise questions about explanations that require the presence of hail.

  3. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  4. Grapevine fatty acid hydroperoxide lyase generates actin-disrupting volatiles and promotes defence-related cell death

    Science.gov (United States)

    Wang, Hao; Claudel, Patricia; Riemann, Michael; Hause, Bettina; Hugueney, Philippe; Nick, Peter

    2018-01-01

    Abstract Fatty acid hydroperoxides can generate short-chained volatile aldehydes that may participate in plant defence. A grapevine hydroperoxide lyase (VvHPL1) clustering to the CYP74B class was functionally characterized with respect to a role in defence. In grapevine leaves, transcripts of this gene accumulated rapidly to high abundance in response to wounding. Cellular functions of VvHPL1 were investigated upon heterologous expression in tobacco BY-2 cells. A C-terminal green fluorescent protein (GFP) fusion of VvHPL1 was located in plastids. The overexpression lines were found to respond to salinity stress or the bacterial elicitor harpin by increasing cell death. This signal-dependent mortality response was mitigated either by addition of exogenous jasmonic acid or by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases. By feeding different substrates to recombinantly expressed enzyme, VvHPL1 could also be functionally classified as true 13-HPL. The cognate products generated by this 13-HPL were cis-3-hexenal and trans-2-hexenal. Using a GFP-tagged actin marker line, one of these isomeric products, cis-3-hexenal, was found specifically to elicit a rapid disintegration of actin filaments. This response was not only observed in the heterologous system (tobacco BY-2), but also in a grapevine cell strain expressing this marker, as well as in leaf discs from an actin marker grape used as a homologous system. These results are discussed in the context of a role for VvHPL1 in a lipoxygenase-dependent signalling pathway triggering cell death-related defence that bifurcates from jasmonate-dependent basal immunity. PMID:29659985

  5. Phytofabrication and characterization of monodisperse copper oxide nanoparticles using Albizia lebbeck leaf extract

    Science.gov (United States)

    Jayakumarai, G.; Gokulpriya, C.; Sudhapriya, R.; Sharmila, G.; Muthukumaran, C.

    2015-12-01

    Simple effective and rapid approach for the green synthesis of copper oxide nanoparticles (CONPs) using of Albizia lebbeck leaf extract was investigated in this study. Various instrumental techniques were adopted to characterize the synthesized CONPs, viz. UV-Vis spectroscopy, SEM, TEM, EDS and XRD. The synthesized CONPs were found to be spherical in shape and size less than 100 nm. It could be concluded that A. lebbeck leaf extract can be used as a cheap and effective reducing agent for CONPs production in large scale.

  6. Characterization of Volatiles in Rambutan Fruit (Nephelium lappaceum L.).

    Science.gov (United States)

    Ong; Acree; Lavin

    1998-02-16

    The volatile compounds from the red-skinned cultivar of rambutan, Jitlee (Nephelium lappaceumL.), a tropical fruit native to Southeast Asia, were extracted using both Freon 113 and ethyl acetate solvents. Isolation and characterization of odor-active compounds present in the fruit were mediated by gas chromatography/olfactory (GC/O), chromatography, and spectrometry. Authentic standards were used to determine mass spectral, retention index, and odor match. Of over 100 volatiles detected by GC/MS, twice as many polar volatiles were detected in the ethyl acetate extract as in the nonpolar Freon extract. GC/O analysis also detected more odor-active compounds in the polar extracts. Over 60 compounds in the extracts had some odor activity. The 20 most potent odorants included beta-damascenone, (E)-4,5-epoxy-(E)-2-decenal, vanillin, (E)-2-nonenal, phenylacetic acid, cinnamic acid, unknown 1 (sweaty), ethyl 2-methylbutyrate, and delta-decalactone. On the basis of calculated odor activity values, beta-damascenone, ethyl 2-methylbutyrate, 2,6-nonadienal, (E)-2-nonenal, and nonanal were determined to be the main contributors to the fruit aroma. Taken together, these results indicate that the exotic aroma character of rambutan is the interaction of fruity-sweet and fatty-green odors, with the possible contribution of "civet-like"-sweaty, spicy, and woody notes.

  7. Volatility Spillovers Across Petroleum Markets

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2015-01-01

    Roč. 36, č. 3 (2015), s. 309-329 ISSN 0195-6574 R&D Projects: GA ČR GA14-24129S Keywords : Volatility spillovers * Asymmetry * Petroleum markets Subject RIV: AH - Economics Impact factor: 1.662, year: 2015 http://library.utia.cas.cz/separaty/2014/E/barunik-0438407.pdf

  8. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...

  9. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    GCMS), was used to identify volatile compounds at three different temperatures. Fifty volatile compounds, inclusive of 14 acids, 14 alcohols, and 22 esters were identified and quantified in the two brands of indigenous banana beer samples. Only 12 ...

  10. Time-Varying Periodicity in Intraday Volatility

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

    We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

  11. A Fractionally Integrated Wishart Stochastic Volatility Model

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThere has recently been growing interest in modeling and estimating alternative continuous time multivariate stochastic volatility models. We propose a continuous time fractionally integrated Wishart stochastic volatility (FIWSV) process. We derive the conditional Laplace transform of

  12. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    We present and test a model relating a firm's idiosyncratic cost, its exporting status, and the volatilities of its domestic and export sales. In prior models of trade, supply costs for domestic and exports were linear and thus additively separable. We introduce a nonlinear cost function in order...... to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...... has several testable predictions. First, larger firms have lower total and domestic sales volatilities. Second, foreign market volatility increases domestic sales volatilities for exporters. Third, exporters allocate output across both markets in order to reduce total sales volatility. We find...

  13. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  14. Effects of {gamma}-radiation on white tea volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo B.; Silveira, Ana Paula M.; Nunes, Thaise C.F.; Costa, Helbert S.F.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: gbfanaro@ipen.br; Purgatto, Eduardo [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental

    2009-07-01

    Tea is the second most widely consumed beverages in the world and is processed from two and a bud of Camellia sinensis (L.). Depending on the processing may give rise to four mainly teas (green, black, oolong and white tea). The white tea is the one that has recently awakened interest in scientific community due the fact that this tea has more antioxidant property and activity than green tea. A further industrialization and commercialization of these plants become a problem of public health. The presence of potentially toxigenic fungi can be found in these products, indicating a great potential for the presence of mycotoxins that can cause acute and chronic effects in different organs and systems of the human body. Ionizing radiation is one of the most effective means disinfecting dry food ingredients. This treatment can inhibit cellular life division, like microorganisms, promoting a molecular structural modification. The aim of this study was evaluate the effects of radiation on volatile formation in white tea. Samples were irradiated in room temperature at {sup 60}Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20-kGy. The volatiles organic compound was extracted by hydrodistillation and the extract was separated and identified by gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the quantities of volatiles formations are directly proportional to the increase of radiation dose. About 37.86% of the compounds were stable at all radiation doses and 47.53% of new compounds were identified after irradiation. (author)

  15. Effects of γ-radiation on white tea volatiles

    International Nuclear Information System (INIS)

    Fanaro, Gustavo B.; Silveira, Ana Paula M.; Nunes, Thaise C.F.; Costa, Helbert S.F.; Villavicencio, Anna L.C.H.; Purgatto, Eduardo

    2009-01-01

    Tea is the second most widely consumed beverages in the world and is processed from two and a bud of Camellia sinensis (L.). Depending on the processing may give rise to four mainly teas (green, black, oolong and white tea). The white tea is the one that has recently awakened interest in scientific community due the fact that this tea has more antioxidant property and activity than green tea. A further industrialization and commercialization of these plants become a problem of public health. The presence of potentially toxigenic fungi can be found in these products, indicating a great potential for the presence of mycotoxins that can cause acute and chronic effects in different organs and systems of the human body. Ionizing radiation is one of the most effective means disinfecting dry food ingredients. This treatment can inhibit cellular life division, like microorganisms, promoting a molecular structural modification. The aim of this study was evaluate the effects of radiation on volatile formation in white tea. Samples were irradiated in room temperature at 60 Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20-kGy. The volatiles organic compound was extracted by hydrodistillation and the extract was separated and identified by gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the quantities of volatiles formations are directly proportional to the increase of radiation dose. About 37.86% of the compounds were stable at all radiation doses and 47.53% of new compounds were identified after irradiation. (author)

  16. GREEN MANAGEMENT: THE REALITY OF BEING GREEN IN BUSINESS

    OpenAIRE

    Tran, Ben

    2009-01-01

    Green management and going green are not as clear cut and easy as hyped by the general media. While going ecologically green is indeed beneficial and appropriate, the process and procedure of becoming green is anything but easy. Firstly, turning green is largely not a legal requirement, but a voluntary process. Thus, even though LEED (which is by far the more publicly known green certification standard) governs the certification of the green management effort, it is not a compulsory condition...

  17. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    Martin, B.R.; Lue, L.P.; Boni, J.P.

    1989-01-01

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

  18. A nonparametric approach to forecasting realized volatility

    OpenAIRE

    Adam Clements; Ralf Becker

    2009-01-01

    A well developed literature exists in relation to modeling and forecasting asset return volatility. Much of this relate to the development of time series models of volatility. This paper proposes an alternative method for forecasting volatility that does not involve such a model. Under this approach a forecast is a weighted average of historical volatility. The greatest weight is given to periods that exhibit the most similar market conditions to the time at which the forecast is being formed...

  19. 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

  20. Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

    Directory of Open Access Journals (Sweden)

    OLORUNFEMI MICHAEL AJAYI

    2014-05-01

    Full Text Available Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions.

  1. Green energy in Europe: selling green energy with green certificates

    International Nuclear Information System (INIS)

    Ouillet, L.

    2002-01-01

    Sales of green power products are booming in Europe: 50,000 customers in the United Kingdom, 775,000 in the Netherlands and 300,000 in Germany. Laws of physics are however formal: the way in which electricity flows within the grid does not allow suppliers to assure customers that they are directly receiving electricity produced exclusively from renewable energy sources. What are marketers selling their customers then? Laetitia Ouillet, Greenprices, takes a closer look and focuses on the potential of selling green energy in the forms of renewable energy certificates. (Author)

  2. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    Energy Technology Data Exchange (ETDEWEB)

    Maja, Mengistu M., E-mail: mengistu.maja@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Kasurinen, Anne; Holopainen, Toini [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland); Julkunen-Tiitto, Riitta [University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu (Finland); Holopainen, Jarmo K. [University of Eastern Finland, Department of Environmental Science, P.O.Box 1627, 70211 Kuopio (Finland)

    2016-03-15

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  3. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen

    International Nuclear Information System (INIS)

    Maja, Mengistu M.; Kasurinen, Anne; Holopainen, Toini; Julkunen-Tiitto, Riitta; Holopainen, Jarmo K.

    2016-01-01

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient + 2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A + T and UV-B + T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B × temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone

  4. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    NARCIS (Netherlands)

    J. Chen (Jinghui); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The

  5. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  6. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...

  7. 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?.

  8. 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

  9. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves.

    Science.gov (United States)

    Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

    2016-03-08

    Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.

  10. Investigations on Avocado Leaf Oil

    OpenAIRE

    ŞARER, Engin; KÖKDİL, Gamze

    1990-01-01

    Persea americana Mill.(P.gratissima Gârtn.) (Lauraceae) "Avoca - d o " is a small tree native to tropical America and cultivated in southern Turkey. In this study, the volatile oil from the leaves of P.americana has been analyzed by LSC, GLC and GC-MS methods. A light yellow volatile oil with a spicy odour has been obtained with a proportion of 3.0% (v /w) from leaves of P.americana by hydrodistillation. 11 monoterpene hydrocarbon compounds and 9 oxygen containing monoterpenes and s...

  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. Green growth in fisheries

    DEFF Research Database (Denmark)

    Nielsen, Max; Ravensbeck, Lars; Nielsen, Rasmus

    2014-01-01

    harming the environment. Fishery is an environment-dependent sector and it has been argued that there is no potential for green growth in the sector owing to global overexploitation, leaving no scope for production growth. The purpose of this paper is to explain what green growth is and to develop......Climate change and economic growth have gained a substantial amount of attention over the last decade. Hence, in order to unite the two fields of interest, the concept of green growth has evolved. The concept of green growth focuses on how to achieve growth in environment-dependent sectors, without...... a conceptual framework. Furthermore, the aim is to show that a large green growth potential actually exists in fisheries and to show how this potential can be achieved. The potential green growth appears as value-added instead of production growth. The potential can be achieved by reducing overcapacity...

  13. Evidence of isolate-specificity in non-hypersensitive resistance in spring wheat (Triticum aestivum) to wheat leaf rust

    NARCIS (Netherlands)

    Qamar, Maqsood; Niks, R.E.

    2007-01-01

    Isolate-specific aspect of non-hypersensitive resistance in wheat to wheat leaf rust was studied at seedling stage in the green house. Isolate-specific response of non-hypersensitive resistance was assessed from latency period (LP) and infection frequency (IF) of two single-pustule isolates of

  14. Green chemistry of carbon nanomaterials.

    Science.gov (United States)

    Basiuk, Elena V; Basiuk, Vladimir A

    2014-01-01

    The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps.

  15. Money growth volatility and the demand for money in Germany: Friedman's volatility hypothesis revisited

    OpenAIRE

    Brüggemann, Imke; Nautz, Dieter

    1997-01-01

    Recently, the Bundesbank claimed that monetary targeting has become considerably more diffcult by the increased volatility of short-term money growth. The present paper investigates the impact of German money growth volatility on income velocity and money demand in view of Friedman's money growth volatility hypothesis. Granger-causality tests provide some evidence for a velocity-volatility linkage. However the estimation of volatility-augmented money demand functions reveals that - in contras...

  16. 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

  17. Green electricity buyer's guide

    International Nuclear Information System (INIS)

    Kelly, B.; Klein, S.; Olivastri, B.

    2002-06-01

    The electricity produced in whole or in large part from renewable energy sources like wind, small hydro electricity and solar energy, is generally referred to as green electricity. The authors designed this buyer's guide to assist customers in their understanding of green electricity, as the customers can now choose their electricity supplier. The considerations and steps involved in the purchasse of green electricity are identified, and advice is provided on ways to maximize the benefits from the purchase of green electricity. In Alberta and Ontario, customers have access to a competitive electricity market. The emphasis when developing this guide was placed firmly on the large buyers, as they can have enormous positive influence on the new market for green electricity. The first chapter of the document provides general information on green electricity. In chapter two, the authors explore the opportunity for environmental leadership. Chapter three reviews the basics of green electricity, which provides the link to chapter four dealing with the creation of a policy. Purchasing green electricity is dealt with in Chapter five, and maximizing the benefits of green electricity are examined in Chapter Six. 24 refs., 3 tabs

  18. Leaf phenology and wood formation of white cedar trees (Melia azedarach L. and their responses to climate variability

    Directory of Open Access Journals (Sweden)

    Kritsadapan Palakit

    2018-02-01

    Full Text Available This research aimed to investigate the response of leaf phenologies and wood increments of Melia azedarach L. on climate variability. The visual estimation indicated the leaf flushing in January-July, the leaf maturation in January-November, and the leaf abscission in May-June and October-December. Monthly wood investigations of the inside bark diameters (IBD indicated an annual-ring formation with the wood increment in February-November and the dormancy in December-January. The outside bark diameter (OBD exhibited growth variations with phases of slow increment in September-October, shrinkage in December-February, and fast increment in March-August. The relationship among monthly climates, leaf phenologies and wood increments, indicated the significant correlations of the soil moisture and the abundances of mature dark green leaves on the IBD, while the OBD was fluctuated due to the direct effect of the IBD and the indirect effect of the soil moisture and mature dark green leaf abundances.

  19. Impact of microorganism on polonium volatilization

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Fukuda, A.; Yoshinaga, C.

    2007-01-01

    Volatilization of polonium by microorganisms, Chromobacterium violaceum, Escherichia coli and Bacillus subtilis was examined for pure cultures in LB medium at 30 deg C, showing relative Po emission intensity 100, 10 and 1, respectively. Chromobacterium violaceum pre-cultured in LB medium without Po and suspended in water with Po showed high Po volatilization in spite of poor nutriment condition. Antibiotics inhibit volatilization of Po and cultivation at low temperature greatly reduced volatilization. The results strongly support the biological effects on Po volatilization. (author)

  20. 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.)

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. GREEN PACKAGING, GREEN PRODUCT, GREEN ADVERTISING, PERSEPSI, DAN MINAT BELI KONSUMEN

    OpenAIRE

    Imam Santoso; Rengganis Fitriani

    2016-01-01

    Environmental problems become one of the strategic issues in achieving global competitiveness. One of the issues is products that are made from environmental friendly materials or known as green product. Furthermore, in green products marketing, the company also uses green packaging and green advertising concept. This study aimed to analyze the effect of green packaging, green products, and green advertising on consumer perception and purchasing intention. The study was conducted in Ketawangg...

  10. Volatilization of iodine from vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Amiro, B D; Johnston, F L [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Nuclear Research Establishment

    1989-01-01

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na {sup 125}I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author).

  11. Volatile constituents of Trichothecium roseum.

    Science.gov (United States)

    Vanhaelen, M; Vanhaelen-Fastre, R; Geeraerts, J

    1978-06-01

    In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

  12. Chirospecific analysis of plant volatiles

    International Nuclear Information System (INIS)

    Tkachev, A V

    2007-01-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  13. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  14. Forecasting volatility of crude oil markets

    International Nuclear Information System (INIS)

    Kang, Sang Hoon; Kang, Sang-Mok; Yoon, Seong-Min

    2009-01-01

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  15. Forecasting volatility of crude oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  16. 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.

  17. Money, banks and endogenous volatility

    OpenAIRE

    Pere Gomis-Porqueras

    2000-01-01

    In this paper I consider a monetary growth model in which banks provide liquidity, and the government fixes a constant rate of money creation. There are two underlying assets in the economy, money and capital. Money is dominated in rate of return. In contrast to other papers with a larger set of government liabilities, I find a unique equilibrium when agents' risk aversion is moderate. However, indeterminacies and endogenous volatility can be observed when agents are relatively risk averse.

  18. Forecasting volatility for options valuation

    International Nuclear Information System (INIS)

    Belaifa, M.; Morimune, K.

    2006-01-01

    The petroleum sector plays a neuralgic role in the basement of world economies, and market actors (producers, intermediates, as well as consumers) are continuously subjected to the dynamics of unstable oil market. Huge amounts are being invested along the production chain to make one barrel of crude oil available to the end user. Adding to that are the effect of geopolitical dynamics as well as geological risks as expressed in terms of low chances of successful discoveries. In addition, fiscal regimes and regulations, technology and environmental concerns are also among some of the major factors that contribute to the substantial risk in the oil industry and render the market structure vulnerable to crises. The management of these vulnerabilities require modern tools to reduce risk to a certain level, which unfortunately is a non-zero value. The aim of this paper is, therefore, to provide a modern technique to capture the oil price stochastic volatility that can be implemented to value the exposure of an investor, a company, a corporate or a Government. The paper first analyses the regional dependence on oil prices, through a historical perspective and then looks at the evolution of pricing environment since the large price jumps of the 1970s. The main causes of oil prices volatility are treated in the third part of the paper. The rest of the article deals with volatility models and forecasts used in risk management, with an implication for pricing derivatives. (author)

  19. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  20. Volatilization of gasoline from soil

    International Nuclear Information System (INIS)

    Arthus, P.

    1993-05-01

    Gasoline contaminated soil threatens water resources and air quality. The extent of the threat depends on gasoline behavior in soil, which is affected by various mechanisms such as volatilization. To quantify volatilization, gasoline spills were simulated in the laboratory using a synthetic gasoline and three dry soils. Total gasoline and individual gasoline compound concentrations in soil were monitored as a function of depth and time. The time to reduce overall gasoline concentration in coarse sand, sandy loam, and silt loam to 40% of initial concentration, averaged between surface and a 200-mm depth, ranged from 0.25 d to 10 d. A wicking phenomenon which contributed to gasoline flux toward the atmosphere was indicated by behavior of a low-volatility gasoline compound. Based on separate wicking experiments, this bulk immiscible movement was estimated at an upward velocity of 0.09 m/d for Delhi sandy loam and 0.05 m/d for Elora silt loam. 70 refs., 24 figs., 34 tabs

  1. Phytochemical screening and chemical variability in volatile oils of aerial parts of Morinda morindoides.

    Science.gov (United States)

    Kiazolu, J Boima; Intisar, Azeem; Zhang, Lingyi; Wang, Yun; Zhang, Runsheng; Wu, Zhongping; Zhang, Weibing

    2016-10-01

    Morinda morindoides is an important Liberian traditional medicine for the treatment of malaria, fever, worms etc. The plant was subjected to integrated approaches including phytochemical screening and gas chromatography mass spectrometry (GC-MS) analyses. Phytochemical investigation of the powdered plant revealed the presence of phenolics, tannins, flavonoids, saponins, terpenes, steroidal compounds and volatile oil. Steam distillation followed by GC-MS resulted in the identification of 47 volatiles in its aerial parts: 28 were in common including various bioactive volatiles. Major constituents of leaves were phytol (43.63%), palmitic acid (8.55%) and geranyl linalool (6.95%) and stem were palmitic acid (14.95%), eicosane (9.67%) and phytol (9.31%), and hence, a significant difference in the percentage composition of aerial parts was observed. To study seasonal changes, similarity analysis was carried out by calculating correlation coefficient (r) and vector angle cosine (z) that were more than 0.91 for stem-to-stem and leaf-to-leaf batches indicating considerable consistency.

  2. 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.

  3. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Developing agricultural opportunities on mine tailings : the Green Mines green energy initiative

    Energy Technology Data Exchange (ETDEWEB)

    Tisch, B.; Spiers, G.; Beckett, P.; Lock, A. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2009-02-15

    The goal of the Green Mines green energy initiative is to advance mine reclamation through the beneficial use of organic residuals for the sustainable establishment of bioenergy crops and other productive land uses. Target organic residuals include: source separated organic compost; papermill biosolids; leaf and yard waste compost; and municipal wastewater biosolids. This presentation discussed the Green Mines green energy initiative with particular reference to potential uses; current participants; scope of the initiative; and progress to date. The presentation also discussed a column study that involved adding filter, filter fabric, silica sand and polyethylene beads to the base of columns. Unoxidized tailings were slurried and pumped into columns and then the oxidized tailings were dried and homogenized. The results of acidic copper/nickel tailings with lime and no lime were also discussed. A summary of findings from the column study was offered. It was found that nutrient management must be considered and organic covers appear to increase metal and arsenic leaching from unlimed tailings. The presentation also made reference to demonstration field plots; biosolids delivery; tilling; monitoring; biomass sampling; and harvesting. The presentation concluded with a discussion of next steps which involve completing construction of the current suite of field plots and implementing full monitoring. figs.

  5. 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

  6. Customers’ Intention to Use Green Products: the Impact of Green Brand Dimensions and Green Perceived Value

    Directory of Open Access Journals (Sweden)

    Doszhanov Aibek

    2015-01-01

    Full Text Available This study aimed to identify the relationships between green brand dimension (green brand awareness, green brand image, and green brand trust, green perceived value and customer’s intention to use green products. Data was collected through structured survey questionnaire from 384 customers of three hypermarkets in Kuala-Lumpur. Data was analyzed based on multiple regression analysis. The results indicate that there are significant relationships between green brand awareness, green brand trust, green perceived value, and customer’s intention to use green products. However, green brand image was not found to have significant relationship with customer’s intention to use green products. The discussion presented suggestions for marketers and researchers interested in green branding.

  7. Locomotion and attachment of leaf beetle larvae Gastrophysa viridula (Coleoptera, Chrysomelidae)

    OpenAIRE

    Zurek, Daniel B.; Gorb, Stanislav N.; Voigt, Dagmar

    2015-01-01

    While adult green dock leaf beetles Gastrophysa viridula use tarsal adhesive setae to attach to and walk on smooth vertical surfaces and ceilings, larvae apply different devices for similar purposes: pretarsal adhesive pads on thoracic legs and a retractable pygopod at the 10th abdominal segment. Both are soft smooth structures and capable of wet adhesion. We studied attachment ability of different larval instars, considering the relationship between body weight and real contact area between ...

  8. Greening the Future

    Science.gov (United States)

    Williamson, Norma Velia

    2011-01-01

    Because educators vicariously touch the future through their students, the author believes that they sometimes have the uncanny ability to see the future. One common future forecast is the phenomenal growth of green jobs in the emerging green economy, leading to the creation of the "Reach of the Sun" Solar Energy Academy at La Mirada…

  9. Green Buildings and Health.

    Science.gov (United States)

    Allen, Joseph G; MacNaughton, Piers; Laurent, Jose Guillermo Cedeno; Flanigan, Skye S; Eitland, Erika Sita; Spengler, John D

    2015-09-01

    Green building design is becoming broadly adopted, with one green building standard reporting over 3.5 billion square feet certified to date. By definition, green buildings focus on minimizing impacts to the environment through reductions in energy usage, water usage, and minimizing environmental disturbances from the building site. Also by definition, but perhaps less widely recognized, green buildings aim to improve human health through design of healthy indoor environments. The benefits related to reduced energy and water consumption are well-documented, but the potential human health benefits of green buildings are only recently being investigated. The objective of our review was to examine the state of evidence on green building design as it specifically relates to indoor environmental quality and human health. Overall, the initial scientific evidence indicates better indoor environmental quality in green buildings versus non-green buildings, with direct benefits to human health for occupants of those buildings. A limitation of much of the research to date is the reliance on indirect, lagging and subjective measures of health. To address this, we propose a framework for identifying direct, objective and leading "Health Performance Indicators" for use in future studies of buildings and health.

  10. Green product innovation strategy

    NARCIS (Netherlands)

    Driessen, P.H.

    2005-01-01

    Over the last decades, companies have started to incorporate green issues in product innovation strategies. This dissertation studies green product innovation strategy, its antecedents and its outcomes. A three-stage approach is followed. In the first stage, the topic is explored and a preliminary

  11. Green for rarity

    International Nuclear Information System (INIS)

    Raal, F.A.; Robinson, D.N.

    1980-01-01

    Green diamonds once recovered from Witwatersrand gold/uranium deposits, are now a thing of the past with the modernisation of extraction metallurgy methods. The green colouration has been shown to be due to radiation from uranium present in the ore

  12. Green Building Research Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sailor, David Jean [Portland State Univ., Portland, OR (United States)

    2013-12-29

    This project provided support to the Green Building Research Laboratory at Portland State University (PSU) so it could work with researchers and industry to solve technical problems for the benefit of the green building industry. It also helped to facilitate the development of PSU’s undergraduate and graduate-level training in building science across the curriculum.

  13. Green Cleaning Label Power

    Science.gov (United States)

    Balek, Bill

    2012-01-01

    Green cleaning plays a significant and supportive role in helping education institutions meet their sustainability goals. However, identifying cleaning products, supplies and equipment that truly are environmentally preferable can be daunting. The marketplace is inundated with products and services purporting to be "green" or environmentally…

  14. Introduction: Experimental Green Strategies

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research.......Defining new ways in which archietcts are responding to the challenge of creating sustainable architecture , Experimental Green Strategies present a state of the art in applied ecological architectural research....

  15. Discussion Tourism Industry on Energy of Green Tourism and Green Hotel

    Directory of Open Access Journals (Sweden)

    Wang Zeyung

    2016-01-01

    Full Text Available Tourism industry is closely linked with the natural environment but with a highly indivisibility of symbiotic relationship. Green tourism and green tourism hotel are not only the spindle stage of development industry. The environmental protection is also an environmental conservation and sustainable development of substantive liability demonstration. The study is also belong to the substance RDF itself, so we can call “clean energy”. The raw materials came from agricultural waste through proper blending ratio and control technology, after PP14 adhesive extruded through the fluidized bed pyrolysis cracking process to burn stability. The recovery can also be used as fuel volatile process of drying and gasification. However, in the actual economic cost of the test running the hotel industry can reduce the cost per MJ USD $ 0.0082, more economical than coal expenses 23.17% of the fuel. Therefore, green hotel through biomass fuels RDF as clean fuels can further reduce carbon emissions to reach the green hotel of expectations.

  16. Remote estimation of nitrogen and chlorophyll contents in maize at leaf and canopy levels

    Science.gov (United States)

    Schlemmer, M.; Gitelson, A.; Schepers, J.; Ferguson, R.; Peng, Y.; Shanahan, J.; Rundquist, D.

    2013-12-01

    Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl indices using near infrared (780-800 nm) and either green (540-560 nm) or red-edge (730-750 nm) spectral bands. Spectral bands that were found optimal for Chl and N estimations coincide well with the red-edge band of the MSI sensor onboard the near future Sentinel-2 satellite. The coefficient of determination for the relationships between the red-edge chlorophyll index, simulated in Sentinel-2 bands, and Chl and N content was 0.90 and 0.87, respectively.

  17. Effect of foliar fertilizer and fungicidal protection against leaf spot diseases on winter wheat

    Directory of Open Access Journals (Sweden)

    Agnieszka Mączyńska

    2012-12-01

    Full Text Available Field experiments were carried out in the seasons 2000/2001 and 2001/2002 in Plant Protection Institute, Sooenicowice Branch to assess the influence of foliar fertilizers such as Ekolist PK 1, Ekolist Mg, Mikrosol Z and Urea on healthiness of winter wheat. Foliar fertilizers were mixed with fungicides. The fungicides were applied at full or half recommended doses. The effect of the disease on wheat leaves was evaluated three times in each vegetation season. Remaining green leaf area (GLA of leaves was also determined. GLA of the leaves F-1 was not significantly different for each combination with different fertilization and different levels of chemical treatment. The application of foliar fertilizer only had no effect on green leaf area (GLA. The results indicate that foliar fertilization of all experimental plots improved leaf condition and therefore halted the development of wheat leaf diseases. The increases of 1000 grain mass and yield was high for each plot where a fertilizer and a full or half dose of a fungicide was applied. Foliar fertilizing with no chemical control had no proven effect on studied parameters.

  18. Green heterogeneous wireless networks

    CERN Document Server

    Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

    2016-01-01

    This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

  19. Evaluation of authenticity and green tea antimicrobial activity of different commercial brands that are sold in San Jose, Costa Rica

    International Nuclear Information System (INIS)

    Alvarez Campos, Jeyson

    2014-01-01

    Various brands of green tea are compared with the leaves of camellia sinensis to verify the antimicrobial effect, authenticity and quality. The main components with antibacterial effect commercially presented are compared to the components present in green tea leaf to determine the quality and authenticity, by thin layer chromatography. The brands marketed studied green tea in the metropolitan area of San Jose, Costa Rica has been really green tea good quality, this can be ensured by the findings in the analysis and comparison of the different profiles of flavonoids, polyphenols, alkaloids and amino acids. The antimicrobial activity has been without to confirmed in the bands of catechins analyzed [es

  20. Leaf and canopy photosynthesis of a chlorophyll deficient soybean mutant.

    Science.gov (United States)

    Sakowska, Karolina; Alberti, Giorgio; Genesio, Lorenzo; Peressotti, Alessandro; Delle Vedove, Gemini; Gianelle, Damiano; Colombo, Roberto; Rodeghiero, Mirco; Panigada, Cinzia; Juszczak, Radosław; Celesti, Marco; Rossini, Micol; Haworth, Matthew; Campbell, Benjamin W; Mevy, Jean-Philippe; Vescovo, Loris; Cendrero-Mateo, M Pilar; Rascher, Uwe; Miglietta, Franco

    2018-03-02

    The photosynthetic, optical, and morphological characteristics of a chlorophyll-deficient (Chl-deficient) "yellow" soybean mutant (MinnGold) were examined in comparison with 2 green varieties (MN0095 and Eiko). Despite the large difference in Chl content, similar leaf photosynthesis rates were maintained in the Chl-deficient mutant by offsetting the reduced absorption of red photons by a small increase in photochemical efficiency and lower non-photochemical quenching. When grown in the field, at full canopy cover, the mutants reflected a significantly larger proportion of incoming shortwave radiation, but the total canopy light absorption was only slightly reduced, most likely due to a deeper penetration of light into the canopy space. As a consequence, canopy-scale gross primary production and ecosystem respiration were comparable between the Chl-deficient mutant and the green variety. However, total biomass production was lower in the mutant, which indicates that processes other than steady state photosynthesis caused a reduction in biomass accumulation over time. Analysis of non-photochemical quenching relaxation and gas exchange in Chl-deficient and green leaves after transitions from high to low light conditions suggested that dynamic photosynthesis might be responsible for the reduced biomass production in the Chl-deficient mutant under field conditions. © 2018 John Wiley & Sons Ltd.

  1. Building the green way.

    Science.gov (United States)

    Lockwood, Charles

    2006-06-01

    Just five or six years ago, the term "green building" evoked visions of barefoot, tie-dyed, granola-munching denizens. There's been a large shift in perception. Of course, green buildings are still known for conserving natural resources by, for example, minimizing on-site grading, using alternative materials, and recycling construction waste. But people now see the financial advantages as well. Well-designed green buildings yield lower utility costs, greater employee productivity, less absenteeism, and stronger attraction and retention of workers than standard buildings do. Green materials, mechanical systems, and furnishings have become more widely available and considerably less expensive than they used to be-often cheaper than their standard counterparts. So building green is no longer a pricey experiment; just about any company can do it on a standard budget by following the ten rules outlined by the author. Reliable building-rating systems like the U.S. Green Building Council's rigorous Leadership in Energy and Environmental Design (LEED) program have done much to underscore the benefits of green construction. LEED evaluates buildings and awards points in several areas, such as water efficiency and indoor environmental quality. Other rating programs include the UK's BREEAM (Building Research Establishment's Environmental Assessment Method) and Australia's Green Star. Green construction is not simply getting more respect; it is rapidly becoming a necessity as corporations push it fully into the mainstream over the next five to ten years. In fact, the author says, the owners of standard buildings face massive obsolescence. To avoid this problem, they should carry out green renovations. Corporations no longer have an excuse for eschewing environmental and economic sustainability. They have at their disposal tools proven to lower overhead costs, improve productivity, and strengthen the bottom line.

  2. Stochastic volatility models and Kelvin waves

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, Alex [Merrill Lynch, Mlfc Main, 2 King Edward Street, London EC1A 1HQ (United Kingdom); Sepp, Artur [Merrill Lynch, 4 World Financial Center, New York, NY 10080 (United States)], E-mail: Alex_Lipton@ml.com, E-mail: Artur_Sepp@ml.com

    2008-08-29

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  3. Stochastic volatility models and Kelvin waves

    Science.gov (United States)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  4. Stochastic volatility models and Kelvin waves

    International Nuclear Information System (INIS)

    Lipton, Alex; Sepp, Artur

    2008-01-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics

  5. Uncertainty of Volatility Estimates from Heston Greeks

    Directory of Open Access Journals (Sweden)

    Oliver Pfante

    2018-01-01

    Full Text Available Volatility is a widely recognized measure of market risk. As volatility is not observed it has to be estimated from market prices, i.e., as the implied volatility from option prices. The volatility index VIX making volatility a tradeable asset in its own right is computed from near- and next-term put and call options on the S&P 500 with more than 23 days and less than 37 days to expiration and non-vanishing bid. In the present paper we quantify the information content of the constituents of the VIX about the volatility of the S&P 500 in terms of the Fisher information matrix. Assuming that observed option prices are centered on the theoretical price provided by Heston's model perturbed by additive Gaussian noise we relate their Fisher information matrix to the Greeks in the Heston model. We find that the prices of options contained in the VIX basket allow for reliable estimates of the volatility of the S&P 500 with negligible uncertainty as long as volatility is large enough. Interestingly, if volatility drops below a critical value of roughly 3%, inferences from option prices become imprecise because Vega, the derivative of a European option w.r.t. volatility, and thereby the Fisher information nearly vanishes.

  6. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  7. Ozone Flux Measurement and Modelling on Leaf/Shoot and Canopy Scale

    Directory of Open Access Journals (Sweden)

    Ludger Grünhage

    Full Text Available The quantitative study of the ozone effects on agricultural and forest vegetation requires the knowledge of the pollutant dose absorbed by plants via leaf stomata, i.e. the stomatal flux. Nevertheless, the toxicologically effective dose can differ from the stomatal flux because a pool of scavenging and detoxification processes reduce the amount of pollutant responsible of the expression of the harmful effects. The measurement of the stomatal flux is not immediate and the quantification of the effective dose is still troublesome. The paper examines the conceptual aspects of ozone flux measurement and modelling in agricultural and ecological research. The ozone flux paradigm is conceptualized into a toxicological frame and faced at two different scales: leaf/shoot and canopy scales. Leaf and shoot scale flux measurements require gas-exchange enclosure techniques, while canopy scale flux measurements need a micrometeorological approach including techniques such as eddy covariance and the aerodynamical gradient. At both scales, not all the measured ozone flux is stomatal flux. In fact, a not negligible amount of ozone is destroyed on external plant surfaces, like leaf cuticles, or by gas phase reaction with biogenic volatile compounds. The stomatal portion of flux can be calculated from concurrent measurements of water vapour fluxes at both scales. Canopy level flux measurements require very fast sensors and the fulfilment of many conditions to ensure that the measurements made above the canopy really reflect the canopy fluxes (constant flux hypothesis. Again, adjustments are necessary in order to correct for air density fluctuations and sensor-surface alignment break. As far as regards flux modelling, at leaf level the stomatal flux is simply obtained by multiplying the ozone concentration on the leaf with the stomatal conductance predicted by means of physiological models fed by meteorological parameter. At canopy level the stomatal flux is

  8. 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...

  9. Clarkesville Green Infrastructure Implementation Strategy

    Science.gov (United States)

    The report outlines the 2012 technical assistance for Clarkesville, GA to develop a Green Infrastructure Implementation Strategy, which provides the basic building blocks for a green infrastructure plan:

  10. 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.

  11. Inflation Volatility and the Inflation-Growth Tradeoff in India

    OpenAIRE

    Raghbendra Jha; Varsha S. Kulkarni

    2012-01-01

    This paper amends the New Keynesian Phillips curve model to include inflation volatility and tests the determinants of such volatility for India. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL (1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility along (in the ECM model) and not in the other models. Major det...

  12. Volatile accretion history of the Earth.

    Science.gov (United States)

    Wood, B J; Halliday, A N; Rehkämper, M

    2010-10-28

    It has long been thought that the Earth had a protracted and complex history of volatile accretion and loss. Albarède paints a different picture, proposing that the Earth first formed as a dry planet which, like the Moon, was devoid of volatile constituents. He suggests that the Earth's complement of volatile elements was only established later, by the addition of a small veneer of volatile-rich material at ∼100 Myr (here and elsewhere, ages are relative to the origin of the Solar System). Here we argue that the Earth's mass balance of moderately volatile elements is inconsistent with Albarède's hypothesis but is well explained by the standard model of accretion from partially volatile-depleted material, accompanied by core formation.

  13. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Macroeconomic Volatility and Welfare in Developing Countries

    OpenAIRE

    Loayza, Norman V.; Rancière, Romain; Servén, Luis; Ventura, Jaume

    2007-01-01

    Macroeconomic Volatility and Welfare in Developing Countries: An Introduction Norman V. Loayza, Romain Ranciere, Luis Serven, ` and Jaume Ventura Macroeconomic volatility, both a source and a reflection of underdevelopment, is a fundamental concern for developing countries. This article provides a brief overview of the recent literature on macroeconomic volatility in developing countries, highlighting its causes, consequences, and possible remedies. to reduce domestic policy-induced macroecon...

  15. Identify and Manage the Software Requirements Volatility

    OpenAIRE

    Khloud Abd Elwahab; Mahmoud Abd EL Latif; Sherif Kholeif

    2016-01-01

    Management of software requirements volatility through development of life cycle is a very important stage. It helps the team to control significant impact all over the project (cost, time and effort), and also it keeps the project on track, to finally satisfy the user which is the main success criteria for the software project. In this research paper, we have analysed the root causes of requirements volatility through a proposed framework presenting the requirements volatility causes and how...

  16. Labour Demand and Exchange Rate Volatility

    OpenAIRE

    Udo Broll; Sabine Hansen

    2004-01-01

    The purpose of this paper is to assess under what conditions exchange rate volatility exerts a positive effect on a firm's labour demand. As the exchange rate volatility increases, so does the value of the export option provided the firm under study is flexible. Flexibility is important because it gives the firm option value. Higher volatility increases the potential gains from trade and may increase the demand for labour. This may explain part of the mixed empirical findings regarding the ef...

  17. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    John Y. Campbell; Glen B. Taksler

    2002-01-01

    This paper explores the effect of equity volatility on corporate bond yields. Panel data for the late 1990s show that idiosyncratic firm-level volatility can explain as much cross-sectional variation in yields as can credit ratings. This finding, together with the upward trend in idiosyncratic equity volatility documented by Campbell, Lettau, Malkiel, and Xu (2001), helps to explain recent increases in corporate bond yields. The definitive version is available at www.blackwell-synergy.com.

  18. Selling the green dream

    International Nuclear Information System (INIS)

    Wood, E.

    2005-01-01

    The article discusses the marketing and sales of energy generated from renewable energy sources. To purchase environmental energy in the USA, the consumer need do no more than tick a box on a sheet of paper. But, it is not just households that opt for green energy: businesses are also willing customers. A factor in the success in selling green energy to big business is that the retail price of wind power can be held constant over periods of several years, whereas fossil fuel prices can fluctuate wildly. Details of sources and sales of the top ten companies selling green energy are given

  19. Manufacturing Green Consensus

    DEFF Research Database (Denmark)

    Gulsrud, Natalie Marie; Ooi, Can Seng

    2014-01-01

    In an increasingly global economy, being green, or having an environmentally sustainbale place brand, provides a competitive advantage. Singapore, long known as the ``garden city´´ has been a leader in green city imaging since the founding of the equatorial city-state, contributing, in large part...... to the city’s profile as the economic giant of Southeast Asia. Using a political ecology lens, the paper aims to uncover the contested socio-economic narratives of green city imaging by examining the evolution of the garden city branding scheme since Singapore’s independence in 1959. Results show...

  20. About green political parties

    Directory of Open Access Journals (Sweden)

    Orlović Slobodan P.

    2015-01-01

    Full Text Available In this work the author refers to some legal and political questions in connection with green political parties. Those questions cover: the ideology of green political parties, their number and influence, both in general and in Serbia. The first part of work is generally speaking about political parties - their definition, ideology, role and action. Main thesis in this work is that green political parties, by their appearance, were something new on the political scene. But quickly, because of objective and subjective reasons, they were changing original ideas and were beginning to resemble to all other political parties. In this way, they lost their vanguard and political alternativeness.