Biosynthetic origin of carbon-based secondary compounds: cause of variable responses of woody plants to fertilization?

Summary. We propose that variation in the responses of carbon-based secondary compounds to fertilization in woody plants has a biosynthetic cause. The synthesis of phenylpropanoids and derived compounds (e.g., condensed tannins) competes directly with the synthesis of proteins, and therefore with plant growth, because of a common precursor, phenylalanine. In contrast, the biosynthesis of terpenoids and of hydrolyzable tannins proceeds presumably without direct competition with protein synthesis. Therefore, accelerated plant growth induced by fertilization may cause a reduction in concentrations of phenylpropanoids but may affect less or not at all the levels of other classes of secondary compounds. A meta-analysis based on fertilization experiments with 35 woody plant species supported the predicted differences fertilizing significantly decreased concentrations of phenylpropanoids but not of terpenoids or hydrolyzable tannins. Received 14 May 1998; accepted 23 June 1998.     

Geno-toxicity assay of sediment and water samples from the Upper Silesia post-mining areas, Poland by means of Allium-test

Genotoxic potential of two environmental compartments (water and sediment) from the Upper Silesia Coal Basin (USCB), Poland were evaluated and compared by employing root meristem cells of Allium cepa. The clear genotoxic effect of water and sediment sampled was shown, with an important contribution of severe types of cytogenetic abnormalities. The most biologically relevant pollutants were revealed through multivariate statistical analysis of relationships between biological effects registered and the environment contamination. Overall, results of simultaneous use of conventional monitoring methods and biological tests suggested that contemporary levels of persistent pollutants in post-mining areas of the USCB may enhance the risk both for human health and biological components of natural ecosystems.     

Biodegradation of polystyrene-graft-starch copolymers in three different types of soil

Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30 %). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93 %), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77 %) that is preventing biodegradation of degradable part of copolymers.     

Economic,social and environmental dimension of sustainable competitiveness of European countries

Over the last decade, promotion of competitiveness represents one of the central goals of economic policy of most of the countries. Moreover, in recent years, the promotion of competitiveness has been seen as a way of achieving desirable changes in economy and society. While there is no unity of views in the theory regarding the conceptual definition of the phenomenon of competitiveness, it is becoming less arguable that in strictly economic terms, competitiveness is a synonym for productivity. However, it should be noted that productivity growth that is accompanied by increasing social imbalance (for example, inequality in income distribution), on the one hand, and environmental pollution, on the other hand, cannot be a guarantee of improving the competitiveness of countries in the long run. Acknowledging precisely this fact and using the data from World Economic Forum on Global Competitiveness 2013, this paper elaborates on the phenomenon of sustainable competitiveness and tests the hypothesis about the positive impact of its social and environmental dimension on the economic dimension of sustainable competitiveness that is represented by the value of the Global Competitiveness Index. The survey of 34 countries confirmed the indisputable positive impact of the social dimension of sustainability, but also variable direction of the impact of the environmental dimension of sustainability (depending on the level of GDP per capita) on the economic dimension of sustainable competitiveness of European countries in 2013.     

Investigations on the sorption of a toxaphene model congener, the B7-1450, on marine sediments

Sorption is a natural process that takes place in sediments or soils and changes the mobility and availability of hydrophobic organic compounds, such as toxaphene pesticide in the environment. The sorption of the 2-exo,3-endo,5-exo,8,9,10,10-heptachlorobornane (B7-1450), used as a model compound of the toxaphene heptachlorobornane congeners found in sediments, was investigated for the first time through a series of batch sorption experiments. The losses of B7-1450 due to adsorption onto glass walls and to evaporation occurring during analytical treatment steps were corrected. The study showed that these specific losses ranged from 2% to 3.5% for the glass walls adsorption and can be as high as 15% for the evaporation treatment. The sorption coefficients, K(d) and K(oc), of B7-1450 could be overestimated by >30%, particularly for low-concentration samples, if the losses were not corrected. Loss correction equations were established, validated and applied to determine sorption coefficients for the B7-1450 congener. The K(oc) values for B7-1450 determined over a gradient of concentrations ranged from 3.5x10(4) to 6.5x10(4)mlg(-1), revealing a strong affinity of B7-1450 for marine sediments.     

Comparative assessment of pollution by the use of industrial agricultural fertilizers in four rapidly developing Asian countries

This article describes a study of the environmental impacts of the use of industrial agricultural chemicals in four Asian countries—China, India, the Philippines and Thailand. The objective was to contribute objectively to the discussion on the extent of the problem, past and current damages to the environment to and outline possible paths to sustainable and environmentally benign agriculture. The four countries are experiencing rapid economic growth under a tremendous population growth pressure that, with the exception of China, will continue without leveling of in a foreseeable future. This requires more food production that has been accomplished by the increased use of industrial chemical fertilizers. Although the four countries uses of industrial chemicals vary, the mix of nutrients appears to be imbalanced, resulting in large nitrogen losses into the environment, especially in China. A suggested solution of the problem begins with reducing (China) or maintaining (India, the Philippines, Thailand) average nutrient application levels needed by the crops and includes optimal hybrid agriculture by using organic fertilizers, and fertilizers in the irrigation water already overloaded with nitrogen. There is a need to balance fertilizer N and P applications with the crop needs.     

Antibiotic resistance and virulence factors of Escherichia coli from eagles and goshawks

One of the major global problems in medicine is microbial resistance to antibiotics (antimicrobial resistance) and this has become an increasingly frequent research topic. This study focuses on antimicrobial resistance, phylogenetic and genetic characterization of Escherichia coli from wild birds: ten isolates from eagles (Aquila chrysaetos), nine from goshawks (Accipiter gentilis) and 24 from broilers in the Slovak Republic. Twenty-two strains with presence of int1 gene were selected and examined for the presence or absence of transposon gene (tn3), genes of antibiotic resistance and virulence factors. We detected sequence type (ST) in eagles ST 442 with genes iss, papC, iutA, cvaC, tsh, fyuA, iroN, kps, feoB, sitA, irp2, ireA for virulence factors and tetA, sul1, sul2, dfrA, aadA for antibiotic resistance; in goshawks ST 1011 with iss, papC, fyuA, iroN, feoB, sitA and qnrS1, tetA, sul1, sul2, dfrA, aadA, respectively. These ST types have been found in humans too and should be evaluated further for possible zoonotic potential and transfer of resistance genes from the environment.     

Reductive dechlorination of polychlorinated dibenzo-p-dioxins by zerovalent iron in subcritical water

A new method for reductive dechlorination of polychlorinated dibenzo-p-dioxins (PCDDs) and remediation of contaminated soils is described that uses zerovalent iron as the dechlorination agent and subcritical water as reaction medium and extractive solvent. It is found that the zerovalent iron can be applied for stepwise dechlorination of octachlorinated dibenzo-p-dioxin (OCDD) on various matrixes in subcritical water. By using iron powder as matrix higher chlorinated congeners were practically completely reduced to less than tetra-substituted homologues. A significant part of residual OCDD, when it was spiked in to soils, and formed less chlorinated congeners are extracted with water in the given conditions. The solubility of OCDD was increased by a 4–6 orders over its solubility at ambient conditions. The new method of contentious-flow extraction is described.     

Temporal and spatial variations of air pollution across China from 2015 to 2018

This study investigated concentrations of PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃, and air quality index（AQI） values across 368 cities in mainland China during 2015–2018. The study further examined relationships of air pollution status with local industrial capacities and vehicle possessions. Strong correlations were found between industrial capacities（coal, pig iron, crude steel and rolled steel） and air pollution levels. Although statistical and ...