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  • Open Access

    ARTICLE

    Photoresponsive Multilayer Films of Chitosan and an Azopolymer

    Raquel Fernández*, Connie Ocando, Susana C. M. Fernandes, Arantxa Eceiza, Agnieszka Tercjak

    Journal of Renewable Materials, Vol.3, No.1, pp. 49-55, 2015, DOI:10.7569/JRM.2014.634134

    Abstract The main goal of this work was the development of photoactive multilayer fi lms. Taking into account that chitosan is a biodegradable, biocompatible, nontoxic, and antibacterial biopolymer, the fabrication of chitosanbased multilayer fi lms can be an interesting pathway to obtain biopolymer-based fi lms in which properties can be combined with a light-responsive material, such as an azobenzene-containing polymer. In particular, the layer-by-layer technique was used for the fabrication of the optically active fi lms consisting of alternating layers of chitosan and an azopolymer. The infl uence of the pH and the number of bilayers More >

  • Open Access

    ARTICLE

    A state and transition model for the eastern Monte Phytogeographycal Province in Rio Negro

    Kröpfl AI1, VA Deregibus2, GA Cecchi3

    Phyton-International Journal of Experimental Botany, Vol.84, No.2, pp. 390-396, 2015, DOI:10.32604/phyton.2015.84.390

    Abstract We developed a functional model for a shrub steppe vegetation of the eastern Monte Phytogeographical Province in Río Negro (Argentina) with six stable states and 12 transitions, based on the woody encroachment degree, characteristics of the herbaceous layer and the soil surface, and biological crust cover. Information was obtained from letters of naturalists and travelers along the region since the late eighteenth century, reports of old settlers, and our own research work. On the Monte, different functional groups can be distinguished. Our work focused on the three most conspicuous to analyze the dynamics of the… More >

  • Open Access

    ARTICLE

    Biofilter efficiency of Eichhornia crassipes in wastewater treatment of fish farming in Amazonia

    Rubim MAL1, PR Isolino Sampaio1, P Parolin2,3

    Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 244-251, 2015, DOI:10.32604/phyton.2015.84.244

    Abstract Fish is a very important part of the human diet in Amazonia. Near the growing cities, fish populations and individual size have decreased over the past decades. Alternatives to traditional and industrial fishing arise, including fish farming. Strategies to minimize the impact of fish farms on the environment are needed to have a regular and healthy fish supply. This is to avoid a reduction of biodiversity, a depletion of natural resources, and/or the induction of significant changes in the structure and functioning of adjacent ecosystems. Very little research has been performed on management of effluents… More >

  • Open Access

    ARTICLE

    Effects of grazing on plant species diversity and carbon partitioning in semiarid rangelands of northeastern China

    Hu FL1,2, B Liu1,3, ZM Liu1,3, YT Fang1,3, CA Busso4

    Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 209-221, 2015, DOI:10.32604/phyton.2015.84.209

    Abstract Grasslands are one of the most widespread landscapes worldwide, covering approximately one-fifth of the world’s land surface, where grazing is a common practice. How carbon storage responds to grazing in steppes remains poorly understood. We quantified the effects of grazing on community composition and species diversity, and carbon storage in two typical grasslands of northeastern China, one in Horqin and the other one in Hulunbeier. In both grasslands, grazing did not influence plant species diversity. However, it substantially decreased aboveground carbon by 31% and 54% in Horqin and Hulunbeier, respectively. Fenced and grazing treatments showed More >

  • Open Access

    ARTICLE

    A Probabilistic Approach to Hazard Mapping Based on Computer Simulations. An Example for Lava Flows at Mount Etna

    R. Rongo1,2, D. D’Ambrosio1,2, G. Iovine2,3, F. Lucà4, V. Lupiano5, V.P.Boñgolan6, W. Spataro1,2

    CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 105-130, 2015, DOI:10.3970/cmes.2015.109.105

    Abstract Determining sectors that could be affected by lava flows in volcanic areas is essential for risk mitigation purposes. Traditionally, when adopting methods based on probabilistic numerical simulations, the hazard is assessed by analysing a huge set of simulations of hypothetical events, each characterized by a distinct probability of occurrence based on statistics of historical events. If lateral or eccentric eruptions are also taken into account, simulated lava flows usually start from the nodes of regular grids of potential vents, uniformly covering the study area. In this study, an alternative approach to evaluate flow-type hazard, based More >

  • Open Access

    ARTICLE

    Contribution of different bud types to community regeneration on a typical steppe under various enclosure durations in Inner Mongolia, China

    Qian J1,2, Z Wang1, Z Liu1, W Kuang1,2, CA Busso3

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 407-414, 2014, DOI:10.32604/phyton.2014.83.407

    Abstract Understanding the changes in the total bud bank, and its contribution to community regeneration, in response to grassland enclosure to livestock grazing, is crucial for grassland management. Despite its importance, the contribution of the total bud bank and that of different bud types to community regeneration as a whole have been rarely explored. The vegetative offspring recruited from different bud types was investigated in grasslands having different enclosure durations to livestock grazing on a typical steppe of Inner Mongolia, China. Total vegetative offspring density was significantly higher (p<0.05) under continuous grazing than in fenced grasslands,… More >

  • Open Access

    ARTICLE

    Delimitation of Azadirachta indica A. Juss. from Melia azedarach L. (Meliaceae Juss.) based on leaf morphology

    Usama K Abdel-Hameed

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 363-367, 2014, DOI:10.32604/phyton.2014.83.363

    Abstract In Egypt there are two different species that are commercially marketed under the same trade name of Neem: one is Azadirachta indica A. Juss., and the other is Melia azedarach L. In this paper, leaf morphological characters (e.g., lamina architecture, stomatography, petiole and blade micromorphology) of both taxa were described and illustrated to aid in the identification and differentiation between the two misidentified taxa. The obtained results concluded that leaf morpho-anatomical characters will not only provide criteria for their correct taxonomic authentication, but would also serve as future standard data for the quality assessment of the pharmaceutical More >

  • Open Access

    ARTICLE

    Azospirillum brasilense and Glomus intraradices co-inoculation stimulates growth and yield of cherry tomato under shadehouse conditions

    Lira-Saldivar RH1, A Hernández1, LA Valdez2, A Cárdenas1, L Ibarra1, M Hernández3, N Ruiz4

    Phyton-International Journal of Experimental Botany, Vol.83, pp. 133-138, 2014, DOI:10.32604/phyton.2014.83.133

    Abstract The response of cherry tomato to biofertilization with beneficial microorganisms was evaluated under shadehouse conditions. Seeds were inoculated and/or co-inoculated with Azospirillum brasilense (Az) and/or Glomus intraradices (Gi). Thereafter, seedlings of six treatments received two applications of a suspension containing Az + Gi at 15 and 30 days after the transplant, and were compared against a non-inoculated treatment which only received conventional inorganic fertilization. Seed co-inoculation with A. brasilense and G. intraradices plus two applications of Az + Gi at 15 and 30 days after transplant increased on average 6% plant height, 11% leaf area, 10.5% dry biomass and More >

  • Open Access

    ARTICLE

    Post-treatment with plant extracts used in Brazilian folk medicine caused a partial reversal of the antiproliferative effect of glyphosate in the Allium cepa test

    VIVIANE DAL-SOUTO FRESCURA1, ANDRIELLE WOUTERS KUHN1, HAYWOOD DAIL LAUGHINGHOUSE IV2, JUÇARA TEREZINHA PARANHOS1, SOLANGE BOSIO TEDESCO1

    BIOCELL, Vol.37, No.2, pp. 23-28, 2013, DOI:10.32604/biocell.2013.37.023

    Abstract Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine, either as water infusions, baths or poultices. This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P. birotula on the Allium cepa test. Exposure to distilled water was used as a negative control, while exposure to glyphosate was used as a positive control. The interaction of extracts (as a post-treatment) with the effects of glyphosate was also studied. Results showed that glyphosate and the extracts of both P. brachypoda and P. birotula reduced the mitotic index as compared… More >

  • Open Access

    ARTICLE

    Variation in specific composition and cover in grassland exposed to various grazing pressures in the Monte Rionegrino

    Peter G1,2, FA Funk3, A Loydi4, AI Casalini5, CV Leder4

    Phyton-International Journal of Experimental Botany, Vol.81, pp. 233-237, 2012, DOI:10.32604/phyton.2012.81.233

    Abstract In the western Monte Phytogeographical Province of Rio Negro, vegetation is a shrubby-grassland steppe, where plants are interspersed within a bare soil matrix forming “phytogenic islands”. The objective of this study was to evaluate the specific composition and cover of the study ecological system under different grazing pressures. We selected areas with high, moderate and low grazing intensity at three sites. In each area we established five linear transects, where basal cover and all intercepted species were registered. Sites were arranged through a Principal Component Analysis using the Infostat software. We analyzed similarity between sites, More >

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