Affiner votre recherche
Résultats 1-10 de 11
Nutrient response to diagnostic fertilization of Norway spruce Picea abies (L.) Karst plantations in western Quebec, Canada.
1990
Janicki W. | Jones A.R.C.
Effect of increased carbon dioxide and ozone on leaf spot pathogens of birch
2002
Syrjala, L. | Poteri, M. (Finnish Forest Research Institute, Suonenjoki (Finland). Suonenjoki Research Station)
Both CO2 and ozone increased the diseased leaf area of clone V5952 in Exp. 1 in the year 2000. The size of spots increased most under ozone fumigation, and the number of spots under ozone and CO2 + O3 fumigations. In clone K1659 all fumigation treatments decreased or had no effect on the DLA, or the number and size of the leaf spots. Also the number of fallen leaves under fumigation treatments was higher in clone V5952 than in clone K1659. Analysis of the year 2001 monitoring results is currently going on
Afficher plus [+] Moins [-]Airborne trichloroacetic acid and its deposition in the catchment area of the Caspian sea
1999
Weissflog, L. | Manz, M. | Popp, P. | Elansky, N. | Arabov, A. | Putz, E. | Schuurmann, G. (UFZ-Centre for Environmental Research, Department of Chemical Ecotoxicology, PF 2, 04301 Leipzig (Germany))
On the fine structure of mesophyll- and sieve cells in needles from slightly and severely damaged spruce trees (Picea abies (L.) Karst.) of the "Postturm" site Ratzeburg
1992
Schmitt, U. (Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzbiologie und Holzschutz) | Kristen, U. | Ruetze, M. | Schultze, R.
Potential protective effects of Spirulina platensis on liver, kidney, and brain acrylamide toxicity in rats
2021
Bin-Jumah, May N. | AL-Huqail, Arwa Abdulkreem | Abdelnaeim, Noha | Kamel, Mohamed | Fouda, Maged M A | Abulmeaty, Mahmoud M A | Saadeldin, Islam M. | Abdel-Daim, Mohamed M.
Acrylamide (AA) is a hazardous chemical that is widely used in industrial practices. Spirulina platensis (SP) is a blue green alga that is rich in bioactive compounds with many medicinal benefits. The aim of the present study was to evaluate the ameliorative effect of SP against AA toxicity in rats. Animals were divided into six groups: Group (1) was normal rats, groups (2) and (3) received SP at 500 and 1000 mg/kg BW orally respectively for 21 days, group (4) was administered 20 mg/kg BW AA daily for 14 days, while groups (5) and (6) were given orally SP at the same doses of groups (2) and (3), then AA at similar dose of group (4). Rats that received AA alone displayed markedly increased serum levels of liver enzymes (ALT, AST, and ALP), kidney function parameters (urea and creatinine), DNA damage marker (8-OHdG), and proinflammatory cytokines (IL-1β, IL-6, and TNF-α), compared to control rats. Furthermore, tissue analysis revealed marked increases in hepatic, renal, and brain MDA and NO, as well as marked reductions in the antioxidant biomarkers (GSH, GSH-Px, SOD, and CAT) in acrylamide-intoxicated rats. Spirulina ameliorated the alterations in serum biochemical parameters and reduced MDA and NO, as well as improved antioxidant biomarkers in AA-intoxicated rats in a dose-dependent manner. Our results show that SP has a powerful protective effect on serum biochemistry and liver, kidney, and brain antioxidant machinery in AA-intoxicated rats.
Afficher plus [+] Moins [-]Atmospheric Absorption of Fluoride by Cultivated Species. Leaf Structural Changes and Plant Growth
2011
Mesquita, Geisa Lima | Tanaka, Francisco André Ossamu | Cantarella, Heitor | Mattos, Dirceu Jr
Fluoride (F) is an air pollutant that causes phytotoxicity. Besides the importance of this, losses of agricultural crops in the vicinity of F polluting industries in Brazil have been recently reported. Injuries caused to plant leaf cell structures by excess F are not well characterized. However, this may contribute to understanding the ways in which plant physiological and biochemical processes are altered. A study evaluated the effects of the atmospheric F on leaf characteristics and growth of young trees of sweet orange and coffee exposed to low (0.04 mol L−1) or high (0.16 mol L−1) doses of HF nebulized in closed chamber for 28 days plus a control treatment not exposed. Gladiolus and ryegrass were used as bioindicators in the experiment to monitor F exposure levels. Fluoride concentration and dry mass of leaves were evaluated. Leaf anatomy was observed under light and electron microscopy. High F concentrations (~180 mg kg−1) were found in leaves of plants exposed at the highest dose of HF. Visual symptoms of F toxicity in leaves of citrus and coffee were observed. Analyses of plant tissue provided evidence that F caused degeneration of cell wall and cytoplasm and disorganization of bundle sheath, which were more evident in Gladiolus and coffee. Minor changes were observed for sweet orange and ryegrass. Increase on individual stomatal area was also marked for the Gladiolus and coffee, and which were characterized by occurrence of opened ostioles. The increased F absorption by leaves and changes at the structural and ultrastructural level of leaf tissues correlated with reduced plant growth.
Afficher plus [+] Moins [-]Organochlorine Contamination in Selected Estuarine and Coastal Marine Finfish and Shellfish of New Jersey
1998
Kennish, Michael J. | Ruppel, Bruce E.
Analysis of PCB, DDT, and chlordane contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey (U.S.A.) indicates consistently highest organochlorine contaminant levels in samples from the north and northeast regions of the state in proximity to industrialized sites. Gas chromatographic analysis of tissue samples from three finfish species (bluefish, Pomatomus saltatrix; striped bass, Morone saxatilis; weakfish, Cynoscion regalis) and one shellfish species (blue crab, Callinectes sapidus) collected throughout the state during the 1986–1987 and 1988–1991 sampling periods revealed mean PCB, DDT, and chlordane concentrations ranging from 200–5, 380 µg g⁻¹ wet weight, 25.14–492.52 µg kg⁻¹ wet weight, and 5–106.44 µg kg⁻¹ wet weight, respectively. A major conclusion of this study is that some commercially and recreationally important finfish and shellfish species in New Jersey waters, especially those which are lipid-rich, have continued to accumulate PCBs, DDTs and chlordane from the environment long after restrictive regulations were first placed on their use in the United States during the 1970s. The greatest impact of organochlorine contamination is nearby urban centers, most notably Newark and New York City.
Afficher plus [+] Moins [-]Trace element accumulation in the tissues of fish from lakes with different pH values
1990
Stripp, R.A. (United States Dept. of Energy, New York, NY (USA). Environmental Measurements Lab.) | Heit, M. | Bogen, D.C. | Bidanset, J. | Trombetta, L.
Elemental patterns in roots and foliage of mature spruce across a gradient of soil aluminium
1988
Joslin, J.D. (Tennessee Valley Authority, Muscle Shoals, AL (USA). Air Quality Branch) | Kelly, J.M. | Wolfe, M.H. | Rustad, L.E.
Growth and elemental uptake of Rhodes grass (Chloris gayana) grown in a mine waste-contaminated soil amended with fly ash-enriched vermicompost
2020
Lukashe, Noxolo Sweetness | Mnkeni, Pearson Nyari Stephano | Mupambwa, Hupenyu Allan
Vegetation cover in mine waste-affected soils is necessary to ensure sustainability of these fragile ecosystems. This study evaluated the potential of fly ash-enriched vermicompost (FV) to improve growth of Chloris gayana in a gold mine waste-affected soil. The treatments in the study were based on optimizing phosphorus supplied as vermicompost at 20 mg P and 40 mg P per kilogram soil which were compared to triple super phosphate (TSP) applied at 40 mg P/kg. The 40-mg P/kg FV treatment resulted in 38.4%, 164% and 182.5% significant increase in shoot height, shoot biomass and root biomass, respectively, relative to the control. The increased biomass was reflected in the plant tissue analysis where 40 mg P/kg FV had high P, Ca, Mg and K, though not significantly different to the 20-mg P/kg FV treatment. Amendment effect had no influence on plant tissue N, Pb, Cd and As. Chloris gayana uptake of Fe, Mn, Zn and Cr was significantly reduced with addition of the vermicompost, whereas Cu and B were significantly increased in the 40-mg P/kg FV treatment relative to the control though the increases did not exceed the critical concentration limits of these elements. Therefore, re-vegetation of mine waste-contaminated soils can be achieved with addition of FV at a rate of 40 mg P/kg FV. However, more studies may need to be done under field conditions to further evaluate the effectiveness of such vermicomposts in improving the re-vegetation capacity of mine waste-contaminated soils.
Afficher plus [+] Moins [-]