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Environmental Pollution (environmental + pollution)
Selected AbstractsNanomaterials and the environment: The views of the Royal Commission on Environmental Pollution (UK)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2010M.H. Depledge [source] Contaminant-associated alteration of immune function in black-footed albatross (Phoebastria nigripes), a North Pacific predatorENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007Myra E. Finkelstein Abstract Environmental pollution is ubiquitous and can pose a significant threat to wild populations through declines in fitness and population numbers. To elucidate the impact of marine pollution on a pelagic species, we assessed whether toxic contaminants accumulated in black-footed albatross (Phoebastria nigripes), a wide-ranging North Pacific predator, are correlated with altered physiological function. Blood samples from adult black-footed albatrosses on Midway Atoll, part of the Hawaiian (USA) archipelago, were analyzed for organochlorines (e.g., polychlorinated biphenyls [PCBs] and chlorinated pesticides), trace metals (silver, cadmium, tin, lead, chromium, nickel, copper, zinc, arsenic, selenium, and total mercury), and a sensitive physiological marker, peripheral white blood cell immune function (mitogen-induced lymphocyte proliferation and macrophage phagocytosis). We found a positive significant relationship between organochlorines, which were highly correlated within individual birds (p < 0.001, r > 0.80, Spearman correlation for all comparisons; PCBs, 160 ± 60 ng/ml plasma [mean ± standard deviation]; DDTs, 140 ± 180 ng/ml plasma; chlordanes, 7.0 ± 3.6 ng/ml plasma; hexachlorobenzene, 2.4 ± 1.5 ng/ml plasma; n = 15) and increased lymphocyte proliferation (p = 0.020) as well as percentage lymphocytes (p = 0.033). Mercury was elevated in black-footed albatrosses (4,500 ± 870 ng/ml whole blood, n = 15), and high mercury levels appeared to be associated (p = 0.017) with impaired macrophage phagocytosis. The associations we documented between multiple contaminant concentrations and immune function in endangered black-footed albatrosses provide some of the first evidence that albatrosses in the North Pacific may be affected by environmental contamination. Our results raise concern regarding detrimental health effects in pelagic predators exposed to persistent marine pollutants. [source] Effects of ethynylestradiol on the reproductive physiology in zebrafish (Danio rerio): Time dependency and reversibilityENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2002Kris Van den Belt Abstract Environmental pollution with natural or synthetic estrogens may pose a serious threat to reproduction of wildlife species. This study describes the effects of 17-,-ethynylestradiol (EE2) on fish reproductive organs in a laboratory model. Adult zebrafish were semistatically exposed to nominal concentrations of 0, 10, and 25 ng/L EE2 for 24 d and then transferred to EE2-free medium. Gonadosomatic index (GSI), plasma vitellogenin concentration (VTG), and histology of the gonads (control and 10 ng/L only) were examined as a function of time. It was found that EE2 has an adverse impact on both male and female reproductive organs. Notably in females, gonadal changes were observed through histological evaluation after 3 d of exposure to 10 ng/L EE2, and this was followed by a reduction of GSI at day 6 of exposure. In males, a reduction of GSI and altered testis histology was found after 24 d of exposure to 10 ng/L. The observed effects on the ovary after EE2 exposure, combined with complete recovery after 24 d, is considered to be triggered by feedback at the level of the pituitary. In both males and females, VTG was induced in response to EE2 and normalized during the recovery period. The observed correlation between VTG and ovarian somatic index (OSI) demonstrates that excessive VTG induction may be predictive for adverse effects of EE2 on ovarian function in female zebrafish. These results indicate that long-term stimulation by synthetic estrogens such as EE2 might impair reproductive function in zebrafish in a reversible manner. [source] DNA damage in Pakistani pesticide-manufacturing workers assayed using the Comet assayENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2006Javed A. Bhalli Abstract The production and use of chemical pesticides has increased in recent years. Although the increased use of pesticides may benefit agriculture, they are also the potential source of environmental pollution, and exposure to pesticides can have negative consequences for human health. In the present study, we have assessed DNA damage in blood leukocytes from 29 Pakistani pesticide-factory workers and 35 controls of similar age and smoking history. The workers were exposed to various mixtures of organophosphates, carbamates, and pyrethroids. DNA damage was measured with the single cell gel electrophoresis (SCGE) assay or Comet assay, using the mean comet tail length (,m) as the DNA damage metric. Exposed workers had significantly longer comet tail lengths than the controls (mean ± SD 19.98 ± 2.87 vs. 7.38 ± 1.48, P < 0.001). Of the possible confounding factors, smokers had significantly longer mean comet tail lengths than nonsmokers and exsmokers for both the workers (21.48 ± 2.58 vs.18.37 ± 2.28, P < 0.001) and the controls (8.86 ± 0.56 vs. 6.79 ± 1.31, P < 0.001), while age had a minimal effect on DNA damage (P > 0.05 and P < 0.05 for workers and controls, respectively). The results of this study indicate that occupational exposure to pesticides causes DNA damage. Environ. Mol. Mutagen., 2006. © 2006 Wiley-Liss, Inc. [source] Cell-cycle deregulation in BALB/c 3T3 cells transformed by 1,2-dibromoethane and folpet pesticidesENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 5 2003Maria Alessandra Santucci Abstract The cell-transforming potential of 1,2-dibromoethane and folpet, two widely used agricultural pesticides that are potential sources of environmental pollution, has been previously ascribed to their promoting activity. In this study, we investigated whether BALB/c 3T3 transformation by these chemicals was associated with the deregulation of signals involved in cell-cycle progression and in cell-cycle checkpoint induction. We found that two BALB/c 3T3 cell clones transformed by in vitro medium-term (8-week) exposure to the carcinogens had a constitutive acceleration of cell transition from G1 to S phase and an abrogation of the radiation-induced G1/S checkpoint. These events involved multiple signals; in particular, the inhibitors of cyclin/cyclin-dependent kinase complexes p21 and p27 were significantly down-modulated and the positive regulators of cell-cycle progression cyclin D3 and E were up-modulated. As anticipated for cells where the G1/S checkpoint was abrogated, the transformed cells exhibited a significant reinforcement of the radiation-induced G2/M checkpoint, the only checkpoint remaining to protect genomic integrity. However, cyclin A1 and B1 coexpression and cyclin A1 overexpression were found despite the G2 arrest in irradiated cells and these signals likely attenuate the G2/M checkpoint. These alterations to normal cell cycling may promote the emergence of both numerical and structural chromosomal abnormalities and their tolerance. Such a condition could play a key role in neoplastic transformation and be crucial in tumor progression. Furthermore, cyclin A1 overexpression may play an autonomous role in the neoplastic transformation of BALB/c 3T3 cells, as it does in other cell types of mesenchymal origin. Environ. Mol. Mutagen. 41:315,321, 2003. © 2003 Wiley-Liss, Inc. [source] The evolution of Chinese policies and governance structures on environment, energy and climateENVIRONMENTAL POLICY AND GOVERNANCE, Issue 3 2010Stephen Tsang Abstract Although a successor to the 1997 Kyoto Protocol has not yet materialized, the 2009 Copenhagen meeting underlined the importance of China in international debates on climate and energy. This is based not only on China's current climate emissions, but also on its expected energy use and economic growth. Within China, climate issues have, like environmental pollution more generally, received increasing government and societal attention, but so has energy , topics that relate to one other but also have different priorities and actor interests behind them. However, while climate change has become more prominent, as shown in the targets included in the current five-year plan, its institutional embeddedness in relation to particularly energy issues has received limited attention. This paper aims to help shed some light on how Chinese policies and governance structures on energy, climate and environment have evolved, particularly considering the roles of national and provincial authorities. Administrative structures and policy-making processes turn out to be very complex, with a range of units and bodies at different levels with distinct responsibilities as well as inter-linkages. Moreover, tensions and conflicts can be found regarding climate change and environmental policies on the one hand, and prevailing objectives to further economic development on the other. Energy policies serve the same economic goals, with climate change being most often operationalized in terms of energy conservation. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment. [source] Genotoxicity in wood mice (Apodemus sylvaticus) along a pollution gradient: Exposure-, age-, and gender-related effectsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2006Jan Scheirs Abstract We investigated the effects of environmental pollution on genetic damage in wood mice (Apodemus sylvaticus) by means of the comet assay, with special attention to the role of age and gender as potential confounding variables. The present study was carried out at four sites along a pollution gradient in the vicinity of Antwerp (Belgium), with a nonferrous smelter as the main pollution source. We measured the concentration of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) in mouse liver and kidney and the concentration of organochlorine compounds (polychlorinated biphenyls and 1,1-dichloro-2,2-bis(p -chlorophenyl)ethylene) in mouse muscle tissue to assess individual exposure. Cadmium exposure was very high at the sites closest to the smelter, and exposure to this metal decreased with increasing distance from the smelter. Exposure to the other pollutants was low to moderate at the different sites. Genetic damage was higher in mice from populations in the vicinity of the nonferrous smelter compared with that in the control populations. A significant increase in genetic damage with age was observed at the most polluted sites, but not at the control sites. Genetic damage was higher in male mice than in female mice at the most polluted site, but not at the other areas. Yet, no obvious relationship was found between individual pollutant levels and individual genetic damage levels. We conclude that the comet assay can be used to compare genotoxicity at the population level if the confounding variables of gender and age are taken into account. However, its use for individual health risk assessment remains questionable. [source] Effects of environmental pollution on microsatellite DNA diversity in wood mouse (Apodemus sylvaticus) populationsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005Veerle Berckmoes Abstract Ten microsatellite DNA loci were surveyed to investigate the effects of heavy metal pollution on the genetic diversity and population genetic structure of seven wood mouse (Apodemus sylvaticus) populations along a heavy metal pollution gradient away from a nonferrous smelter in the south of Antwerp (Flanders, Belgium). Analysis of soil heavy metal concentrations showed that soil Ag, As, Cd, Cu, and Pb decreased with increasing distance from the smelter. Genetic analyses revealed high levels of genetic variation in all populations, but populations from the most polluted sites in the gradient did not differ from those of less-polluted sites in terms of mean observed and expected heterozygosity level and mean allelic richness. No correlation was found between measures of genetic diversity and the degree of heavy metal pollution. However, an analysis of molecular variance and a neighbor-joining tree suggested a contamination-related pattern of genetic structuring between the most polluted and less polluted sites. Pairwise FST values indicated that populations were significantly genetically differentiated, and assignment tests and direct estimates of recent migration rates suggested restricted gene flow among populations. Additionally, genetic differentiation increased significantly with geographical distance, which is consistent with an isolation-by-distance model. We conclude that, at least for our microsatellite DNA markers, genetic diversity in the studied wood mouse populations is not affected greatly by the heavy metal pollution. [source] Fluoride concentrations in antler bone of roe deer (Capreolus capreolus) indicate decreasing fluoride pollution in an industrialized area of western GermanyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2001Uwe Kierdorf Abstract In order to reconstruct temporal changes in ambient fluoride levels in the industrialized Ruhr area (western Germany), we analyzed the bone fluoride content of 167 antlers of roe deer (Capreolus capreolus) killed between 1951 and 1999 in the northern part of this region. Individual values ranged between 110 and 8,178 mg F,/kg ash, and there was an overall marked decrease over the sampling period. Average bone fluoride concentrations in antlers from the periods 1980 through 1989 (geometric mean [95% confidence interval]: 1,490 [1,193,1,861] mg/kg ash) and 1990 through 1999 (753 [644,882] mg/kg ash) differed significantly (p < 0.001) and were both significantly (p < 0.001) lower than those from the periods 1951 through 1969 (3,720 [3,227,4,288] mg/kg ash) and 1970 through 1979 (2,573 [2,203,3,006] mg/kg ash). The findings are seen as indicative of a progressively reduced atmospheric fluoride deposition into the study area, caused by effective emission-control measures in Germany and neighboring countries. Because antlers are replaced annually, grow during a fixed period of some months, and are regularly collected and kept as trophies, they are well suited as monitoring units for analyzing temporal trends in environmental pollution by fluoride and other bone-seeking pollutants. [source] Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plantENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2000William A. Hopkins Abstract Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. We document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr, and V, compared with conspecifics from the reference sites. In addition, malformed larvae from the most contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. We hypothesize that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance. [source] Age,environment model for breast cancerENVIRONMETRICS, Issue 3 2004Nobutane Hanayama Abstract In the field of breast cancer study, it has become accepted that crucial exposures to environmental risks might have occurred years before a malignant tumor is evident in human breasts, while age factors such as ages at menstruation have been known as risks for the disease already. To project trends in two such kinds of risks for the disease, the concept of environment effects is introduced for (age, period)-specific breast cancer mortality rates. Also, a new model, named the age,environment (AE) model, which assumes that the logarithm of the expected rate is a linear function of environment effects and age effects, is proposed. It is shown that, although environment effects have different meanings from period effects or cohort effects, in the age,period,cohort (APC) model, the range space of the design matrix for the AE model is included in that for APC model. It is seen, however, that the AE model provides a better fit to the data for females in Japan and the four Nordic countries than does the APC model in terms of AIC. From the results of ML estimation of the parameters in the AE model based on the data obtained in Japan, we see high levels of environment effects associated with the Sino,Japanese war, World War II and the environmental pollution due to the economy in the recovery period from the defeat. Besides, from those based on the data obtained in the four Nordic countries, we see high levels of environment effects associated with the environment becoming worse after the year of Helsinki Olympics and low levels of them associated with the period including the year of ,Miracle of the Winter War' in Finland. Copyright © 2004 John Wiley & Sons, Ltd. [source] The production of n -3 long-chain polyunsaturated fatty acids in transgenic plantsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 11 2006Johnathan A. Napier Abstract Long-chain polyunsaturated fatty acids (LC-PUFA) now have a proven role in human health and nutrition, including the n -3 forms normally found in fish oils. Unfortunately, global fish stocks are now more than ever subject to over-fishing and environmental pollution, indicating the need for an alternative source of fish oils. Recent efforts have focussed on the production of LC-PUFA in transgenic plants to provide a sustainable and clean source of fish oils. The current progress in this area is considered, as well as the bottlenecks that remain to be overcome. [source] Refrigerated transport and environmentINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2004S. K. Chatzidakis Abstract The regulations and the technical specifications for international carriage of perishable foodstuffs and for the special equipment to be used for such carriage are prescribed in the international ATP Agreement. The refrigerated special equipment has to be checked for quality conformity with the ATP standards, at officially designated national ATP test stations. Some of the alternatively proposed ATP testing procedures for checking of the in-service and second-hand refrigerated transport equipment are incomplete and can give incorrect test results. The consequence is increase in energy consumption and an increased environmental pollution through CO2 emission. This study analyses the ATP testing procedures for in-service equipment, investigates the impact on the environmental and gives some proposals for improvement. Copyright © 2004 John Wiley & Sons, Ltd. [source] Integration of magnetism and heavy metal chemistry of soils to quantify the environmental pollution in Kathmandu, NepalISLAND ARC, Issue 4 2005Pitambar Gautam Abstract Soil profiles of the Kathmandu urban area exhibit significant variations in magnetic susceptibility (,) and saturation isothermal remanence (SIRM), which can be used to discriminate environmental pollution. Magnetic susceptibility can be used to delineate soil intervals by depth into normal (< 10,7 m3/kg), moderately enhanced (10,7,< 10,6 m3/kg) and highly enhanced (, 10,6 m3/kg). Soils far from roads and industrial sites commonly fall into the ,normal' category. Close to a road corridor, soils at depths of several centimeters have the highest ,, which remains high within the upper 20 cm interval, and decreases with depth through ,moderately magnetic' to ,normal' at approximately 30,40 cm. Soils in the upper parts of profiles in urban recreational parks have moderate ,. Soil SIRM has three components of distinct median acquisition fields (B1/2): soft (30,50 mT, magnetite-like phase), intermediate (120,180 mT, probably maghemite or soft coercivity hematite) and hard (550,600 mT, hematite). Close to the daylight surface, SIRM is dominated by a soft component, implying that urban pollution results in enrichment by a magnetite-like phase. Atomic absorption spectrometry of soils from several profiles for heavy metals reveals remarkable variability (ratio of maximum to minimum contents) of Cu (16.3), Zn (14.8) and Pb (9.3). At Rani Pokhari, several metals are well correlated with ,, as shown by a linear relationship between the logarithmic values. At Ratna Park, however, both , and SIRM show significant positive correlation with Zn, Pb and Cu, but poor and even negative correlation with Fe (Mn), Cr, Ni and Co. Such differences result from a variety of geogenic, pedogenic, biogenic and man-made factors, which vary in time and space. Nevertheless, for soil profiles affected by pollution (basically traffic-related), , exhibits a significant linear relationship with a pollution index based on the contents of some urban elements (Cu, Pb, Zn), and therefore it serves as an effective parameter for quantifying the urban pollution. [source] The Exploitation of Crop Allelopathy in Sustainable Agricultural ProductionJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2005T. D. Khanh Abstract Crop allelopathy may be useful to minimize serious problems in the present agricultural production such as environmental pollution, unsafe products, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity. Several crops including alfalfa, buckwheat, maize, rice, rye, sorghum, sunflower, wheat, etc. are affected either by their own toxicity or phytotoxin exudates when their residues decompose in the soil, that show strong suppression on weed emergences. Allelopathic crops when used as cover crop, mulch, smother crops, green manures, or grown in rotational sequences are helpful in reducing noxious weeds and plant pathogen, improve soil quality and crop yield. Those crop plants, particularly the legumes, incorporated at 1,2 tons ha,1 (alfalfa, buckwheat, rice by-products), which can give weed reduction and increase of rice yield by 70 and 20 %, respectively, are suggested for use as natural herbicides. Allelochemicals from allelopathic crops may aid in the development of biological herbicides and pesticides. Cultivating a system with allelopathic crops plays an important role in the establishment of sustainable agriculture. The introduction of allelopathic traits from accessions with strong allelopathic potential to the target crops will enhance the efficacy of crop allelopathy in future agricultural production. [source] Sturgeon aquaculture in China: status of current difficulties as well as future strategies based on 2002,2006/2007 surveys in eleven provincesJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2009By R. Li Summary A nationwide survey in July and August 2007 employed a representative sample of Chinese sturgeon farms from 2002,2006/2007, including data from previous surveys and official statistics dating back to 1998, showing that the development of China's sturgeon aquaculture has progressed steadily in the past few years. Acipenser baerii and Amur hybrids (Acipenser schrenckii × Huso dauricus) have become the dominant cultured species, accounting for 80% of total production. Production centers moved from the southeastern coast towards the midwestern inland provinces, where cold freshwater resources are available in abundance. The paper presents production trends as well as the price structure for commercial fish/meat and juveniles in the various provinces and also considers import and export data for products, fertilized eggs and fingerlings. Results show that: (i) production of juveniles in hatcheries has risen only slightly during the survey period; (ii) the number of larvae obtained from the wild gradually declines each year; (iii) the price for commercial fish/meat drastically declined between 1998 to 2002, but remained stable from 2002 to 2007; and (iv) total production from the 83 surveyed farms was almost stable from 2002 to 2007. Major problems influencing sustainable development of sturgeon aquaculture were identified, including: (i) insufficient domestic supply of larvae and the ban for commercial use of A. sinensis; (ii) disorganized hybridization; (iii) the potential threat to the genetics of natural stocks in the Yangtze River; (iv) diseases originating from environmental pollution and poor-quality fish feed; (v) limited domestic markets; (vi) low volume of sturgeon export due to lack of intensive processing; and (vii) lack of organizational structure in the industry. [source] A cost-effective cane molasses medium for enhanced cell-bound phytase production by Pichia anomalaJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2004A. Vohra Abstract Aim:, Formulation of an inexpensive cane molasses medium for improved cell-bound phytase production by Pichia anomala. Methods and Results:, Cell-bound phytase production by Pichia anomala was compared in synthetic glucose,beef extract and cane molasses media. The yeast was cultivated in 250 ml flasks containing 50 ml of the medium, inoculated with a 12 h-old inoculum (3 × 106 CFU ml,1) and incubated at 25°C for 24 h at 250 rev min,1. Different cultural parameters were optimized in cane molasses medium in batch fermentation. The cell-bound phytase content increased significantly in cane molasses medium (176 U g,1 dry biomass) when compared with the synthetic medium (100 U g,1 dry biomass). In fed-batch fermentation, a marked increase in biomass (20 g l,1) and the phytase yield (3000 U l,1) were recorded in cane molasses medium. The cost of production in cane molasses medium was £0·006 per 1000 U, which is much lower when compared with that in synthetic medium (£0·25 per 1000 U). Conclusions:, An overall 86·6% enhancement in phytase yield was attained in optimized cane molasses medium using fed-batch fermentation when compared with that in synthetic medium. Furthermore, the production in cane molasses medium is cost-effective. Significance and Impact of the Study:, Phytase yield was improved in cane molasses when compared with the synthetic medium, and the cost of production was also significantly reduced. This enzyme can find application in the animal feed industry for improving the nutritional status of feed and combating environmental pollution. [source] Ion channels in toxicologyJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2010Iván Restrepo-Angulo Abstract Ion channels play essential roles in human physiology and toxicology. Cardiac contraction, neural transmission, temperature sensing, insulin release, regulation of apoptosis, cellular pH and oxidative stress, as well as detection of active compounds from chilli, are some of the processes in which ion channels have an important role. Regulation of ion channels by several chemicals including those found in air, water and soil represents an interesting potential link between environmental pollution and human diseases; for instance, de novo expression of ion channels in response to exposure to carcinogens is being considered as a potential tool for cancer diagnosis and therapy. Non-specific binding of several drugs to ion channels is responsible for a huge number of undesirable side-effects, and testing guidelines for several drugs now require ion channel screening for pharmaceutical safety. Animal toxins targeting human ion channels have serious effects on the population and have also provided a remarkable tool to study the molecular structure and function of ion channels. In this review, we will summarize the participation of ion channels in biological processes extensively used in toxicological studies, including cardiac function, apoptosis and cell proliferation. Major findings on the adverse effects of drugs on ion channels as well as the regulation of these proteins by different chemicals, including some pesticides, are also reviewed. Association of ion channels and toxicology in several biological processes strongly suggests these proteins to be excellent candidates to follow the toxic effects of xenobiotics, and as potential early indicators of life-threatening situations including chronic degenerative diseases. Copyright © 2010 John Wiley & Sons, Ltd. [source] Molluscicides from some common medicinal plants of eastern Uttar Pradesh, IndiaJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2010Sunil Kumar Singh Abstract Many aquatic snails act as intermediate hosts for the larvae of trematodes, Fasciola hepatica and Fasciola gigantica, which cause the diseases fascioliasis and schistosomiasis. The WHO has tested several thousands of synthetic compounds for the control of the snail host. Although effective, these molluscicides have so far not proved themselves to be entirely satisfactory. With a growing awareness of environmental pollution, efforts are being made to discover molluscicidal products of plant origin. Being products of biosynthesis, these are potentially biodegradable in nature. Several groups of compounds present in various plants have been found to be toxic to target organisms at acceptable doses ranging from <1 to 100,ppm. Common medicinal plants, i.e. Thevetia peruviana, Alstonia scholaris (Family; Apocynaceae), Euphorbia pulcherima and Euphorbia hirta (Family; Euphorbiaceae), have potent molluscicidal activity against freshwater snails. The toxicological actions of Thevetia peruviana may be due to the presence of apigenin-5-methyl ether (flavonoid) and triterpenoid glycosides, while a number of alkaloids (pseudo-akuammigine in addition to betulin, ursolic acid and ,-sitosterol), steroids and triterpenoids are present in Alstonia scholaris and the diterpenoids, pulcherrol, ,-sitosterol, hentriacontane, ellagic acid and ,-amyrin are present in Euphorbia hirta and in Euphorbia pulcherima. Although, at present very little literature is available on the control of vector snails through plant origin pesticides, an attempt has been made in this review to assemble all the known information on molluscicidal properties of common medicinal plants of eastern Uttar Pradesh, India, which might be useful for the control of harmful snails. Copyright © 2009 John Wiley & Sons, Ltd. [source] Biodesulfurization of dibenzothiophene using recombinant Pseudomonas strainJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2008Lavanya Meesala Abstract BACKGROUND: The sulfur content in crude oil available from various sources ranges from 0.03 to values as high as 8.0 wt%. These high quantities of sulfur must be removed before the crude oil is processed because combustion of this oil would result in severe environmental pollution, such as acid rain. Due to high utility and operating costs, the conventional hydrodesulfurization process (HDS) is considered to be uneconomic. The biotechnological option, biodesulfurization (BDS) seems an attractive low cost, environmentally benign technology. RESULTS: This paper reports the development of a recombinant strain of bacteria designed by introducing desulfurizing, dsz genes containing plasmid pSAD 225-32, which was isolated from Rhodococcus erythropolis IGTS8 into a gram negative solvent-tolerant bacterium, Pseudomonas putida (MTCC 1194). This recombinant bacterium can desulfurize the dibenzothiophene (DBT) in the sulfur selective 4S-pathway. It has been observed that for the same concentration of DBT, the recombinant strain's growth rate is greater than that of the parent strain. Increasing the concentration of DBT resulted in an increase of lag phase as well as decreased growth rate, which shows that the bacteria is following substrate inhibition type kinetics. This genetically modified bacterium can desulfurize 73.1% of 1.2 mmol L,1 DBT (dissolved in ethanol) in 67 h of cultivation time using growing cells. CONCLUSIONS: It is concluded that further research in this area of biodesulfurization using genetically modified organisms may remove the bottlenecks presently in the way of commercialization of the BDS process. Copyright © 2007 Society of Chemical Industry [source] Lipase-mediated methanolysis of soybean oils for biodiesel productionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2008Xin Chen Abstract BACKGROUND: Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Biocatalysis of soybean oils using soluble lipase offers an alternative approach to lipase-catalyzed biodiesel production using immobilized enzyme or whole-cell catalysis. The central composite design (CCD) of response surface methodology (RSM) was used here to evaluate the effects of enzyme concentration, temperature, molar ratio of methanol to oil and stirring rate on the yield of fatty methyl ester. RESULTS: Lipase NS81006 from a genetically modified Aspergillus oryzae was utilized as the catalyst for the transesterification of soybean oil for biodiesel production. The experimental data showed that enzyme concentration, molar ratio of methanol to oil and stirring rate had the most significant impact on the yield of fatty methyl ester; a quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis. The predicted biodiesel yield was 0.928 (w/w) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 0.936 ± 0.014 (w/w) confirmed the validity of the predicted model. CONCLUSION: RSM and CCD were suitable techniques to optimize the transesterification of soybean oil for biodiesel production by soluble lipase NS81006. The related lipase NS81006 reuse stability, chemical or genetic modification, and transesterification mechanism should be taken into consideration. Copyright © 2007 Society of Chemical Industry [source] The status of fish conservation in South African estuariesJOURNAL OF FISH BIOLOGY, Issue 9 2010A. K. Whitfield Estuary-dependent fish species are defined as those taxa whose populations would be adversely affected by the loss of estuarine habitats. Of the 155 species regularly recorded in South African estuaries, only 32 (21%) are completely dependent on these systems, but this figure increases to 103 species (66%) if partially dependent taxa are included in the analysis. The conservation of fishes in estuaries on the subcontinent is threatened by a number of factors, including habitat degradation, disruption of essential ecological processes, hydrological manipulations, environmental pollution, overexploitation due to fishing activities and, more recently, climate change and the effects of introduced aquatic animals. Although major threats to fishes are usually linked to environmental degradation, there is increasing evidence that the stocks of certain fish species are overexploited or collapsed. Fish conservation and fisheries management does not depend on the implementation of a single action, but rather the co-ordination of a detailed plan, often in a multidisciplinary context. Some examples of innovative means of contributing to estuarine fish conservation in a South African context include the determination and implementation of the ecological freshwater requirements for estuaries, the zoning of estuaries for different uses and the recognition that the maintenance of ecological processes are vital to aquatic ecosystem health. Apart from the designation of protected areas, the main direct means of conserving fish species and stocks include habitat conservation, controls over fishing methods, effort, efficiency and seasonality, pollution control and the prevention of artificial manipulation of estuary mouths. Since becoming a democracy in 1994, environmental legislation, policy and institutional arrangements in South Africa have undergone some major changes, which, if fully implemented, will be very positive for fish conservation in estuaries on the subcontinent. [source] Recovery of Components from Shrimp (Xiphopenaeus kroyeri) Processing Waste by Enzymatic HydrolysisJOURNAL OF FOOD SCIENCE, Issue 5 2006Helenice Duarte De Holanda ABSTRACT:, Industrial shrimp waste is a good source of protein, chitin, and carotenoids. In general, this waste is discarded with no attempt to use it, thus contributing to environmental pollution. This study was aimed at recovering the 3 main components of industrial shrimp waste, protein, chitin, and astaxanthin, using enzymatic treatment with Alcalase and pancreatin. An increase in the degree of hydrolysis (DH) from 6% to 12% resulted in 26% to 28% protein recovery. Alcalase was more efficient than pancreatin, increasing the recovery of protein from 57.5% to 64.6% and of astaxanthin from 4.7 to 5.7 mg astaxanthin/100 g of dry waste, at a DH of 12%. The enzymatic hydrolysis of the industrial waste from Xiphopenaeus kroyeri shrimp using Alcalase allowed for 65% protein recovery in the form of hydrolysates, in addition to providing suitable conditions for the recovery of astaxanthin and chitin. [source] Microwave induced efficient synthesis of (un)substituted benzaldehyde (5-aryl-1,3,4-thiadiazol-2-yl)hydrazones using silica-supported dichlorophosphate as a recoverable dehydrantJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2008Zheng Li (Un)substituted benzaldehyde (5-aryl-1,3,4-thiadiazol-2-yl)hydrazones were efficiently synthesized by reactions of (un)substituted benzaldehyde thiocarbohydrazones with aromatic carboxylic acids by using silica-supported dichlorophosphate as a recoverable dehydrant under microwave irradiation. The protocol has advantages of short reaction time, high yield, easy work-up procedure and no environmental pollution. [source] Control of Plant Pathogenic Bacteria of Xanthomonas spp. by the Essential Oil and Extracts of Metasequoia glyptostroboides Miki ex Hu In vitro and In vivoJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2010Vivek K. Bajpai Abstract Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and non-biodegradable and cause extended environmental pollution. Therefore, this study was undertaken to assess the in vitro and in vivo antibacterial efficacy of the essential oil and organic extracts of Metasequoia glyptostroboides against plant pathogenic bacteria of Xanthomonas spp. The oil (1000 ,g/disc) and extracts (1500 ,g/disc) displayed potential antibacterial effect in vitro as a diameter of zones of inhibition against Xanthomonas campestris pv. campestris KC94-17-XCC, X. campestris pv. vesicatoria YK93-4-XCV, X. oryzae pv. oryzae KX019-XCO and X. sp SK12, which were found in the range of 10,14 and 8,12 mm, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of oil and the extracts were ranged from 125,250 and 125 500 ,g/ml and 250,1000 and 250,2000 ,g/ml, respectively. Also the oil had strong detrimental effect on the viable count of the tested bacteria. Further, the oil displayed remarkable in vivo antibacterial effect up to 65 to 100% disease suppression efficacy against the tested strains of Xanthomonas spp. on greenhouse-grown oriental melon plants (Cucumis melo L. var. makuwa). These results suggest that the oil and extracts of M. glyptostroboides could be potential source of natural antibacterials for applying in food and agriculture industries to control plant bacterial diseases caused by Xanthomonas spp. [source] Nitrogen release dynamics and transformation of slow release fertiliser products and their effects on tea yield and qualityJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2008Dr Wen-Yan Han Abstract BACKGROUND: Tea (Camellia sinensis (L.) O. Kuntze) is a perennial leaf harvested crop. It requires more nitrogen than most other crops and preferentially utilises NH4+ to NO3, when both are available in the soil. It is expected that slow release fertilisers coupled with a nitrification inhibitor could improve the N use efficiency and simultaneously reduce environmental pollution. In this study, three slow release fertilisers were developed and tested: CaMg phosphate coated urea with dicyandiamide (DCD) as a nitrification inhibitor and polyolefin coated urea with and without DCD. The main aim was to compare the nitrogen release dynamics and transformation of these fertilisers and their effects on tea yield and quality. RESULTS: The results showed that the coatings significantly slowed N release and kept mineral N in soils at a higher concentration for a longer time compared to uncoated urea. Polyolefin was a superior coating to CaMg phosphate. DCD was an effective nitrification inhibitor and significantly reduced the ratio of nitrate to total mineral N in a highly acidic tea soil. The 15N use efficiency was 29% where uncoated fertiliser was applied and 46% where polyolefin coated fertiliser with DCD was applied. The application of slow release fertilisers increased the chlorophyll content in mature leaves and enhanced the uptake of mineral elements by tea plants. Bud sprouting, shoot growth and mature leaf longevity were significantly improved, resulting in higher biomass of tea plants. Slow release fertilisers increased the yield of shoots by 51,143% (mean, 106%) in a pot experiment and 4,14% (mean, 9%) in a field experiment compared to uncoated urea. Tea quality parameters, especially free amino acids, were also significantly increased. CONCLUSION: Slow release fertilisers, especially polyolefin coated urea with DCD could significantly increase the N use efficiency and improve tea growth. Their uses in tea fields not only improved the profit margin, but possibly reduced environmental pollution. Copyright © 2008 Society of Chemical Industry [source] Chemical characterization of tomato pomaceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2006Marcos Del Valle Abstract Tomato-processing by-product, also known as tomato pomace, consists of peel and seeds and represents around 4% of the fruit weight. If these wastes remain unused, they not only add to the disposal problem but also aggravate environmental pollution. The aim of this paper is to evaluate the chemical composition of tomato pomace collected at different steps during industrial processing in order to assess the quality of this by-product. Twenty-one tomato pomace samples were considered for analysis. Samples corresponded to different steps during tomato processing for paste: seven after pulper, five after finisher, six before turbopress and three after turbopress. Samples were analyzed for moisture content, total and soluble sugars, protein, fat, soluble and total fiber, as well as mineral content. From the results obtained we can conclude that tomato pomace composition (in dry weight basis) is as follows: 59.03% fiber, 25.73% total sugars, 19.27% protein, 7.55% pectins, 5.85% total fat and 3.92% minerals. Copyright © 2006 Society of Chemical Industry [source] Characteristics of sex-biased dispersal and gene flow in coastal river otters: implications for natural recolonization of extirpated populationsMOLECULAR ECOLOGY, Issue 3 2002G. M. Blundell Abstract River otters (Lontra canadensis) were extirpated from much of their historic distribution because of exposure to pollution and urbanization, resulting in expansive reintroduction programmes that continue today for this and other species of otters worldwide. Bioaccumulation of toxins negatively affects fecundity among mustelids, but high vagility and different dispersal distances between genders may permit otter populations to recover from extirpation caused by localized environmental pollution. Without understanding the influence of factors such as social structure and sex-biased dispersal on genetic variation and gene flow among populations, effects of local extirpation and the potential for natural recolonization (i.e. the need for translocations) cannot be assessed. We studied gene flow among seven study areas for river otters (n = 110 otters) inhabiting marine environments in Prince William Sound, Alaska, USA. Using nine DNA microsatellite markers and assignment tests, we calculated immigration rates and dispersal distances and tested for isolation by distance. In addition, we radiotracked 55 individuals in three areas to determine characteristics of dispersal. Gender differences in sociality and spatial relationships resulted in different dispersal distances. Male river otters had greater gene flow among close populations (within 16,30 km) mostly via breeding dispersal, but both genders exhibited an equal, low probability of natal dispersal; and some females dispersed 60,90 km. These data, obtained in a coastal environment without anthropogenic barriers to dispersal (e.g. habitat fragmentation or urbanization), may serve as baseline data for predicting dispersal under optimal conditions. Our data may indicate that natural recolonization of coastal river otters following local extirpation could be a slow process because of low dispersal among females, and recolonization may be substantially delayed unless viable populations occurred nearby. Because of significant isolation by distance for male otters and low gene flow for females, translocations should be undertaken with caution to help preserve genetic diversity in this species. [source] Strategies for development of vaccines for control of ixodid tick speciesPARASITE IMMUNOLOGY, Issue 7 2006J. DE LA FUENTE SUMMARY Ticks are distributed worldwide and impact human and animal health, as well as food animal production. Control of ticks has been primarily by application of acaricides, which has resulted in selection of resistant ticks and environmental pollution. Vaccines have been shown to be a feasible tick control method that offers a cost-effective, environmentally friendly alternative to chemical control. However, identification of tick-protective antigens remains the limiting step in vaccine development. Tick antigens exposed naturally to the host during tick feeding and those concealed have both shown promise as candidate vaccine antigens. Development of vaccines against multiple tick species may be possible using highly conserved tick-protective antigens or by antigens showing immune cross-reaction to different tick species. Vaccines made from a combination of key protective antigens may greatly enhance vaccine efficacy. Preliminary studies have suggested the possibility of vaccine strategies directed toward both tick control and the blocking of pathogen transmission. Characterization of the tick genomes will have a great impact on the discovery of new protective antigens. The future of research directed toward tick vaccine development is exciting because of new and emerging technologies for gene discovery, and vaccine formulation and delivery. [source] The use of life-cycle assessment to evaluate the environmental impacts of growing genetically modified, nitrogen use-efficient canolaPLANT BIOTECHNOLOGY JOURNAL, Issue 4 2008Alison Strange Summary Agriculture, particularly intensive crop production, makes a significant contribution to environmental pollution. A variety of canola (Brassica napus) has been genetically modified to enhance nitrogen use efficiency, effectively reducing the amount of fertilizer required for crop production. A partial life-cycle assessment adapted to crop production was used to assess the potential environmental impacts of growing genetically modified, nitrogen use-efficient (GMNUE) canola in North Dakota and Minnesota compared with a conventionally bred control variety. The analysis took into account the entire production system used to produce 1 tonne of canola. This comprised raw material extraction, processing and transportation, as well as all agricultural field operations. All emissions associated with the production of 1 tonne of canola were listed, aggregated and weighted in order to calculate the level of environmental impact. The findings show that there are a range of potential environmental benefits associated with growing GMNUE canola. These include reduced impacts on global warming, freshwater ecotoxicity, eutrophication and acidification. Given the large areas of canola grown in North America and, in particular, Canada, as well as the wide acceptance of genetically modified varieties in this area, there is the potential for GMNUE canola to reduce pollution from agriculture, with the largest reductions predicted to be in greenhouse gases and diffuse water pollution. [source] | ||||||||||||||||||||||