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Copper Sulphate (copper + sulphate)
Selected AbstractsLake-specific responses in sedimentary sulphur, after additions of copper sulphate to lakes in Michigan, USALAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2009Paul E. Drevnick Abstract Copper sulphate (CuSO4) is commonly added to lakes and reservoirs to manage nuisance and exotic species. Several studies have previously reported that CuSO4 is very useful for this purpose, and that the copper is ultimately stored in lake sediments. In contrast, there has been little study on the fate of the sulphate from CuSO4 additions. The purpose of this study was to elucidate the effects of CuSO4 additions on sedimentary sulphur. Concentrations, isotopes, and fluxes of total and reduced sulphur in sediment cores from four Michigan lakes were compared, including two reference lakes that have never received CuSO4 additions, and two treatment lakes that have received CuSO4 additions by lake managers totalling 1,3 kg sulphate ha,1 year,1 since 1940. The results of this study confirm that sediments do not consistently provide records of sulphate loading across lakes. Isotopic evidence indicates this inconsistency is caused, in part, by lakes with well-mixed sediments, in which sulphate is reduced to sulphide, but then subsequently reoxidized to sulphate and remobilized to the overlying water column. One of the treatment lakes, however, exhibited a clear correlation between CuSO4 additions and an increased sulphur flux to the sediment. During any given year, however, the sulphate added from CuSO4 additions amounted to no more than 10% of the sulphate added from wet deposition. Based on this seemingly insignificant quantity of sulphate, ascribing any effect of CuSO4 additions on sedimentary sulphur is tenuous at best. One possibility is that the addition of CuSO4 at rates that do not overwhelm the natural sulphur cycle of a lake or reservoir is a reasonable management tool for nuisance and exotic species. [source] Phenotypical variation in a toxic strain of the phytoplankter, Cylindrospermopsis raciborskii (nostocales, cyanophyceae) during batch cultureENVIRONMENTAL TOXICOLOGY, Issue 6 2001Peter R. Hawkins Abstract A nonaxenic strain of Cylindrospermopsis raciborskii Woloszynska (AWT 205) was grown in batch culture, with and without nitrate as the primary N source. Rapid log-phase growth with nitrate was 1.0 doubling/day versus 0.3 doubling/day without nitrate. Cylindrospermopsin (CYN) production was measured by HPLC. The rate of intracellular CYN production matched cell division rate for both the diazotrophies at cell densities less than 107 cell/ml. At cell density >107 cell/ml, additional resource limitation in batch culture slowed log-phase growth to 0.04 division/day and cell division and CYN production decoupled. Intracellular CYN concentration increased at a rate of 0.08 doubling/day, twice the cell division rate. Extracellular CYN as a proportion of the total CYN increased from 20% during the rapid growth phase, to 50% during the slow growth phase. The total CYN yield from cultures grown out to stationary phase (55 days) exceeded 2 mg CYN/l. C. raciborskii cells in log-phase growth, exposed to 1 ppm copper (as copper sulphate), lysed within 24 hours. After copper treatment, all CYN was in the filterable fraction. These findings imply that in naturally occurring blooms of C. raciborskii, the movement of intracellular CYN into solution will be the greatest during stationary phase, when intracellular concentrations are highest and cell lysis is more frequent. The application of algicides that promote cell lysis will exacerbate this effect. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 460,467, 2001 [source] Comparison of haemoglobinometry by WHO Haemoglobin Colour Scale and copper sulphate against haemiglobincyanide reference methodINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2004I. S. Timan Summary Although estimation of haemoglobin is essential for diagnosing anaemia and assessing its severity, many health centres in developing countries do not have the facilities for haemoglobinometry. The WHO Haemoglobin Colour Scale (HCS) method is a simple and inexpensive clinical device that was recently developed in order to diagnose anaemia in such centres. In Indonesia, the copper sulphate specific gravity method is used for blood donor screening and also in primary health clinics in the rural and remote areas. In this study, the HCS method is compared with the copper sulphate method and with an earlier paper scale, the Tallquist method, against the standard haemiglobincyanide spectrophotometric method. The HCS method showed an acceptable level of precision and accuracy for use as a reliable screening tool to diagnose anaemia in patients and also for blood donor screening. [source] Susceptibility of channel catfish, Ictalurus punctatus (Rafinesque), to Edwardsiella ictaluri challenge following copper sulphate exposureJOURNAL OF FISH DISEASES, Issue 10 2007B R Griffin Abstract Channel catfish, Ictalurus punctatus (Rafinesque), with or without a preliminary 24 h exposure to 2 mg copper sulphate L,1, were challenged with 7.5 × 106 colony forming units L,1 of Edwardsiella ictaluri to determine the effect of copper sulphate on disease resistance. Catfish previously exposed to copper sulphate were significantly more resistant to the bacterial challenge than those not exposed. Catfish not exposed to copper sulphate suffered 35.5% mortality while catfish exposed to copper sulphate experienced 14.1% mortality. Copper concentrations were the same in tank waters of both exposed and control fish at the time of challenge, eliminating the possibility that copper in the water may have been toxic to bacteria. Copper concentrations in freeze dried and ground tissues of unexposed, exposed, and purged channel catfish were highest in fish before copper sulphate exposures suggesting that elevated tissue levels of copper were not responsible for the increased resistance to bacterial challenge. Competition for sites of bacterial attachment to gill or epithelial cells may account for the reduction in mortality; although this is not supported by the low copper content of fish tissue after copper exposure. [source] The effect of environmental factors on the distribution of Neoparamoeba pemaquidensis in TasmaniaJOURNAL OF FISH DISEASES, Issue 10 2005M Douglas-Helders Abstract Aquaculture in Tasmania is mostly carried out in estuaries. These estuarine habitats show a great variety and form unique environments in which Neoparamoeba pemaquidensis, the amoebic gill disease (AGD)-causing protozoan, may or may not survive. Tasmania is divided into two zones, one where AGD is present and one where AGD is absent, but any ecological data to rationalize this distribution is lacking. In in vitro trials N. pemaquidensis strains were exposed to different concentrations of ammonium sulphate, copper sulphate, copper sulphate and tannin, and different Neoparamoeba densities, salinities and temperatures. A trial using field water samples investigated the survival of N. pemaquidensis in waters sourced from AGD-free and AGD-positive zones, and water analysis was performed to determine any differences. Significantly decreased protozoan survival was found with exposure to increasing copper sulphate concentrations from 10 to 100 000,m (P < 0.001), salinity of 15, (P < 0.001), low Neoparamoeba densities of 625 and 1250 cells mL,1 (P = 0.0005), and water sourced from Macquarie Harbour (P < 0.001). The water chemistry of this AGD-free zone showed significantly lower dissolved calcium and magnesium concentrations which may contribute to this area being AGD-free. Understanding of the ecology of N. pemaquidensis will enable better control and prevention strategies for Tasmanian salmon growers. [source] Acute columnaris infection in channel catfish, Ictalurus punctatus (Rafinesque): efficacy of practical treatments for warmwater aquaculture pondsJOURNAL OF FISH DISEASES, Issue 1 2004S Thomas-Jinu Abstract Columnaris disease was induced in channel catfish, Ictalurus punctatus (Rafinesque), by bath exposure to four highly virulent isolates of Flavobacterium columnare. In untreated controls, mortality began 20 h after exposure and reached 100% by 48 h. Mortality in channel catfish given antibiotic treatments with oxytetracycline or a combination of sulphadimethoxine and ormetoprim in feed prior to bacterial challenge was zero with all four strains of F. columnare. Diquat® (Zeneca Agricultural Products, Wilmington, DE, USA) was the most effective bath treatment; mortality with all four strains was zero. With potassium permanganate, chloramine-T, hydrogen peroxide and copper sulphate, bath treatment efficacy varied significantly among strains (P = 0.0346) and among treatments (P = 0.0033). Bath treatments with chloramine-T and potassium permanganate significantly reduced (P < 0.05) mortality from 100 to 75 and 69%, respectively, but copper sulphate and hydrogen peroxide treatments were not effective. Based on our results, oral antibiotics prevented columnaris disease but, of the bath treatments, only Diquat® produced a dramatic reduction in the mortality of acutely infected fish. Diquat® is labelled for aquatic use as an herbicide in the USA but in large ponds it is prohibitively expensive. [source] Influence of lipase and/or emulsifier addition on the ileal and faecal nutrient digestibility in growing pigs fed diets containing 4% animal fat,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2004NA Dierick Abstract Information on the addition of lipase and/or emulsifiers to less digestible or saturated fat sources, such as tallow or other animal fats, used in swine feeding is very limited. Therefore, in a 4 × 4 Latin square design, the effects of adding lipase (0.05% L5, microbial source) and/or an emulsifier (0.3% Lysoforte) on the apparent ileal (AID) and faecal (AFD) digestibility of the main nutrients and fatty acids in particular were studied with four ileal-cannulated growing pigs (female, initial live weight 20 kg) fed diets containing barley/soybean meal supplemented with 4% animal fat. The fat source contained 35% saturated (S) and 65% unsaturated (U) fatty acids. All diets were free of antibacterial substances (antibiotics, copper sulphate or zinc oxide beyond requirements), in order to avoid interactions between the parameters studied and the gut flora. Lipase addition did not affect the AID or AFD of fat. However, the digestibility of minor fatty acids (C6:0, C14:0) was significantly improved by lipase at both ileal and faecal level. On the other hand, lipase supplementation (P < 0.05) improved the AID of dry matter (DM) and energy as well as the AFD of DM, organic matter (OM), crude protein (CP), ash and energy. Addition of an emulsifier did not have any significant influence on the AID or AFD of fat, while the AID values of DM, OM, CP and energy as well as the AFD values of DM, OM, CP and ash were significantly (P < 0.05) improved. Adding lipase in combination with an emulsifier to the diets decreased (P < 0.05) the AID and AFD of fat, with minor effects on the AID and AFD of the non-fat components of the diet. The lack of improvement in the digestion of fat by exogenous lipase and/or emulsifier may be related to the rather high U/S ratio (0.65:0.35) of the animal fat source used and to the mode of incorporation of the emulsifier (no pre-dispersion in the fat source). Furthermore, during the trial the diets, stored at room temperature, showed a steady increase in their content of free fatty acids (to more than 700 g kg,1 fat), due to endogenous lipase activity, leaving less room for upgrading the digestion of animal fat by exogenous lipase and/or emulsifier. Copyright © 2004 Society of Chemical Industry [source] Lake-specific responses in sedimentary sulphur, after additions of copper sulphate to lakes in Michigan, USALAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2009Paul E. Drevnick Abstract Copper sulphate (CuSO4) is commonly added to lakes and reservoirs to manage nuisance and exotic species. Several studies have previously reported that CuSO4 is very useful for this purpose, and that the copper is ultimately stored in lake sediments. In contrast, there has been little study on the fate of the sulphate from CuSO4 additions. The purpose of this study was to elucidate the effects of CuSO4 additions on sedimentary sulphur. Concentrations, isotopes, and fluxes of total and reduced sulphur in sediment cores from four Michigan lakes were compared, including two reference lakes that have never received CuSO4 additions, and two treatment lakes that have received CuSO4 additions by lake managers totalling 1,3 kg sulphate ha,1 year,1 since 1940. The results of this study confirm that sediments do not consistently provide records of sulphate loading across lakes. Isotopic evidence indicates this inconsistency is caused, in part, by lakes with well-mixed sediments, in which sulphate is reduced to sulphide, but then subsequently reoxidized to sulphate and remobilized to the overlying water column. One of the treatment lakes, however, exhibited a clear correlation between CuSO4 additions and an increased sulphur flux to the sediment. During any given year, however, the sulphate added from CuSO4 additions amounted to no more than 10% of the sulphate added from wet deposition. Based on this seemingly insignificant quantity of sulphate, ascribing any effect of CuSO4 additions on sedimentary sulphur is tenuous at best. One possibility is that the addition of CuSO4 at rates that do not overwhelm the natural sulphur cycle of a lake or reservoir is a reasonable management tool for nuisance and exotic species. [source] Copper-mediated reversal of defective laccase in a ,vph1 avirulent mutant of Cryptococcus neoformansMOLECULAR MICROBIOLOGY, Issue 4 2003Xudong Zhu Summary Previous studies have shown that a ,vph1 Cryptococcus neoformans mutant defective in vesicular acidification lacked several important virulence factors including a copper-containing laccase and was avirulent in a mouse model. In the present studies, we characterized laccase transcription and protein production to obtain insights into the mechanism of the vph1 mutation in this pathogen. Although transcription and protein expression were somewhat reduced, laccase protein was found to be successfully translated and correctly targeted to the cell wall in the ,vph1 mutant as shown by Western blot and immuno-electron microscopy, despite a complete lack of laccase activity. Laccase activity was substantially restored in metabolically active ,vph1 cells at 30°C by addition of 100 µM copper sulphate. This restoration by copper was found to occur through both transcriptional and post-translational mechanisms. Laccase transcriptional induction by copper was found to be dependent on enhancer region II within the 5,-untranslated region of CNLAC1. Copper was also found to restore partial activity to ,vph1 cells at 0°C, suggesting that cell wall laccase was expressed in the mutant as an apo-enzyme. Apo-laccase restoration by copper was found to be facilitated by an acidic environment, consistent with a role for the vacuolar (H+)-ATPase proton pump in copper assembly of laccase in C. neoformans. [source] Free Convective Mass Transfer Behaviour of Inclined Cylinders with Active EndsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2003Inderjit Nirdosh Abstract Rates of mass transfer at inclined cylinders with active ends were determined under natural convection conditions by measuring the limiting current of copper deposition from acidified copper sulphate. Physical properties of the solution, cylinder dimensions and inclination were varied to produce a ScGr range of 1.53 × 109 to 7 × 1010. Under these conditions the data for different orientations were correlated by Sh = 1.075 (ScGr)0.242. The characteristic length used in obtaining Sh and Gr was calculated by dividing the cylinder surface area by the cylinder perimeter projected onto the horizontal plane. At high CuSO4 concentrations a reasonable agreement was found between the experimental rate of mass transfer and that calculated by summing the rate of mass transfer at individual surfaces of the cylinder. Deviations were observed at low CuSO4 concentrations, and the possible causes of the deviations were explained. On a déterminé les taux de transfert de matière dans le cas de cylindres inclinés aux extrémités actives dans des conditions de convection naturelle, en mesurant le courant limite du dépôt de cuivre venant de sulfate de cuivre acidifié. On a fait varier les propriétés physiques de la solution, les dimensions de cylindre et l'inclinaison pour donner une gamme de ScGr de 1.53 × 109 to 7 × 1010. Dans ces conditions, les données pour différentes orientations ont été corrélées par Sh = 1.075 (ScGr)0.242. La longueur caractéristique utilisée pour obtenir Sh et Gr a été calculée en divisant la superficie du cylindre par le périmètre projeté sur un plan horizontal. À de fortes concentrations de CuSO4, un accord raisonnable est trouvé entre le taux de transfert de matière expérimental et celui qui est obtenu en faisant la somme des taux de transfert de matière sur les différentes surfaces du cylindre. Des écarts sont observés à de faibles concentrations de CuSO4, et les causes possibles de ces écarts sont expliquées. [source] | |||||||||||||