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121.
In the period from 1980 to 1984 organic phosphorus, nutrients, primary production rates (14C), chlorophyll a (chl a) standing crops, and basic oceanographic parameters were measured during 23 cruises at six stations in the open waters of the northern Adriatic Sea. These waters are significantly influenced by polluted Po River discharge. Organic phosphorus was correlated with several parameters which characterize phytoplankton activity and organic matter decomposition processes. In the late winter-spring period, organic phosphorus is produced during phytoplankton blooms. It is hypothesized that microzooplankton grazing is the main factor increasing the organic phosphorus concentrations in summer (up to 1.1 mol 1-1). Fall and winter had much lower values (below 0.3 mol 1-1) due to remineralization processes and an increased water mass exchange between the northern and central Adriatic regions. The direct contribution of organic phosphorus by freshwater discharge was not found to be significant. The higher organic phosphorus concentrations that can occur in low salinity waters are most likely due to their increased capability to support primary production.  相似文献   
122.
The influence of copper(II)chloride on selected key enzymes and metabolites in intermediary metabolism and the energy charge potential of the hyperregulating shore crab, Carcinus maenas (L.) were investigated. Crabs, collected in Odense Fjord, Denmark between September 1989 and May 1990, were exposed to 10 ppm copper(II)chloride, in 10 ppt salinity seawater at 15°C for up to 1 wk. Hexokinase activity was 77% lower in the posterior gills and 60% lower in the midgut gland than in control crabs. Phosphofructokinase activity was reduced in the midgut gland by 82% but was unaffected in the gills. Pyruvate kinase activity was undetectable in the gills of exposed crabs and reduced by 47% in the midgut gland. Citrate synthase activity was depressed by 30% in the posterior gills and unaffected in other tissues. Copper exposure had no apparent effect on tissue cytochrome c oxidase activity. Chela muscle was the only tissue in which copper exposure did not bring about reductions in the enzyme activities tested. As a result of 1 wk of copper exposure the average lactate level increased by 3.5-fold in haemolymph, 9.3-fold in posterior gills and 6.5-fold in midgut gland. The average glucose level was raised by a factor of 6 in the haemolymph, 3.4 in the posterior gills and 1.2 in the midgut gland. Energy charge potential was at a very high level (ca. 0.9) and was unaffected by copper exposure.  相似文献   
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Top layer sediment samples from the Czech Republic were analyzed to obtain the preliminary information about contamination of the region by chlorinated paraffins. Sediment samples from three locations with different industrial discharges were taken over the period of 2 years. The analysis was performed by short-column gas chromatography-electron capture negative ion mass spectrometry (SCGC/ECNI-MS). Short chain chlorinated paraffin sediment concentrations varied between 24.00 and 45.78 ng g(-1) (dry weight, d.w.) in the Kosetice area, 16.30-180.75 ng g(-1) (dry weight) in the Zlín area and 4.58-21.57 ng g(-1) dry weight in the Beroun area. Highly chlorinated undecanes prevailed in the samples. On the basis of these results, more detailed studies should be conducted to determine the magnitude and extent of chlorinated paraffin contamination in these regions.  相似文献   
125.
The levels of polychlorinated camphenes (toxaphenes) were investigated in liver samples from 18 glaucous gulls (Larus hyperboreus) from Bj?rn?ya (74 degrees N, 19 degrees E) and four individuals from Longyearbyen (78 degrees N, 15 degrees E). Additionally brominated flame retardants (BFRs), PCBs and chlorinated pesticides were investigated in liver and intestinal contents of 15 of the glaucous gulls from Bj?rn?ya. Of the analysed BFRs only 2,2',4,4'-tetra- and 2,2',4,4',5-pentabrominated diphenylethers (PBDE 47 and 99) could be detected. The concentrations ranged between 2 and 25 ng/g ww. In addition, high resolution measurements with GC/HRMS revealed the existence of several, not quantified, PBDEs and polybrominated biphenyls (PBBs) congeners in the samples. B9-1679 and B8-1413 were the dominating toxaphenes with median concentrations of 8 and 15 ng/g ww. Concentrations of toxaphenes and PBDEs were up to 100-times lower than the concentrations of PCB and some of the pesticides. PCB and p,p/-DDE constituted 90% of the contaminants found.  相似文献   
126.
The effect of metals and ammonia on the relationship between mass concentrations of sulphur dioxide and sulphate in the air was studied near an aluminium plant over a 1-year period. Sulphur dioxide, sulphates and ammonia in the air as well as metals (Pb, Fe, Mn, Zn, Cu, Cd and Al) in the deposit were measured at four measuring sites.The levels of mass concentrations of SO2 were low at all measuring sites while the levels of mass concentrations of sulphates in the air and concentrations of metals in the deposit were high. The levels of ammonia were found to decrease in relationship to the distance from the source of pollution.The relationship between the mass concentrations of sulphate and SO2 can be described by the equation y=ax b ;where y is the percentage of sulphate sulphur in the total sulphur (sulphate and SO2) and x is the mass concentration of the total sulphur in the air. The values of the coefficients a and b are characteristic of individual areas.As the results show the coefficients a and b obtained at a measuring site close to the plant and outside the urban area are characteristic of an industrial area. At control sites in the urban area the coefficients are characteristic of an urban area. At the measuring site close to the industrial zone and the centre of the urban area the interaction of the effects occurs. Therefore, the coefficient a is characteristic of an urban area and b of an industrial one.  相似文献   
127.
Increased cancer incidence and mortality have been found among humans exposed to high levels of organochlorines (OCs), either accidentally or as industrial workers. In order to assess levels of OCs in Norwegian women north of the Arctic Circle and validate self-reported fish consumption as a surrogate measure of organochlorine body burden, concentrations of seven polychlorinated biphenyl (PCB) congeners [IUPAC Nos. CB-105, CB-118, CB-138 (+ CB-163), CB-153, CB-180, CB-183, CB-187], beta-hexachlorocyclohexane (beta-HCH), 2,2'-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) and cis- and trains-chlordane (c-CD and t-CD) were examined in plasma samples of middle-aged women attending for health screening. Altogether, 47 of those invited (81%) completed a questionnaire and donated a suitable blood sample. The ability of questionnaire data to predict plasma levels of OCs was tested in linear and logistic regression analyses. Measured plasma concentrations were in the range reported for the general female population of other Western countries and the relative amounts of PCBs were similar to the circumpolar pattern. Intake of seagulls' eggs was a predictor of PCB congeners CB-138 (+CB-163) (p<0.05) and CB-153 (p<0.01). No other food category was positively associated with any compound. In contrast, duration of residence in the study municipality, body mass index (BMI) and lifetime lactation (months) were the best univariate predictors. There was an increase in beta-HCH, p,p'-DDE and most of the PCBs (p<0.05 for all) with increasing length of time a subject had lived in the municipality. BMI was a positive predictor for beta-HCH (OR=3.10, 95% CI 1.50-6.43, per 5 kgm(-2)), chlordane (OR=2.13, 95% CI 1.12-4.05, per 5 kgm(-2)) and CB-105 and CB-153 (p<0.05 for both). Lactation was negatively associated with all OCs (p<0.05), except chlordane and two of the PCB congeners. Time living in the municipality and lactation explained 34%, of the variance in concentration of total PCB in a multivariate model (p<0.001). The results indicate that regular consumption of fish (mostly lean species) from the Norwegian waters is not associated with an increased body burden of OCs (e.g., of importance to cancer development), although they confirm that lactation is the most important elimination route of these contaminants in women.  相似文献   
128.
The Passenger Pigeon (Ectopistes migratorius) was a social breeder, and it has been suggested that the species experienced functional extinction, defined as a total reproductive failure, prior to its actual extinction in the early years of the 20th century. We applied a novel randomization test based on the relative times of the most recent egg‐ and skin‐specimen sightings (i.e., recorded date of specimen collection) to test for functional extinction. For a total of 6 eggs and 27 skins, the observed significance level was 0.38, which indicated that the species did not become functionally extinct. Thus, proposals to reverse its rapid decline in the late 19th century could have been successful.  相似文献   
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130.
The results of multi-criteria ranking of copper concentrates by their quality, according to their content of useful and harmful components, are presented in this paper. Cu, Ag and Au were taken as useful components, while Pb, Zn, As, Cd, Hg, Bi and Sb were considered as harmful with adequate weight parameters. Considering its specific role in copper metallurgy, sulfur in the concentrate was considered in two scenarios. In the first scenario S was considered as a useful and in the other one as a harmful component. The ranking is done by implementing the PROMETHEE/GAIA method with an additional implementation of the special PROMETHEE V method, using the standard limitations of the heavy metals content in the concentrate. In this way, it is possible to perform an optimization of the input charge for the copper extraction from two aspects. The first aspect covers benefits from the content of useful metals, while the second deals with the protection of the environment, considering the content of harmful components of the charge.Using multi-criteria decision making for the sake of ranking the quality of copper concentrates, as described in this paper, could be considered as a contribution to the methodology of forming the market price of this product.  相似文献   
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