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91.
Kramer GF Lee EH Rowland RA Mulchi CL 《Environmental pollution (Barking, Essex : 1987)》1991,73(2):137-152
Effects of increased ozone (O3) and carbon dioxide (CO2) on polyamine levels were determined in soybean (Glycine max L. Merr. cv. Clark) grown in open-top field chambers. The chamber treatments consisted of three O3 regimes equal to charcoal filtered (CF), non-filtered (NF), and non-filtered plus 40 nl litre(-1) O3 and CO2 treatments equal to 350, 400 and 500 microl litre(-1) for a total of nine treatments. Leaf samples were taken at three different times during the growing season. Examination of growth and physiological characteristics, such as photosynthesis, stomatal resistance, and shoot weight, revealed that increasing CO2 ameliorated the deleterious effects of increased O3. Results from the initial harvest, at the pre-flowering growth stage (23 days of treatment), showed that increasing O3 at ambient CO2 caused increases in putrescine (Put) and spermidine (Spd) of up to six-fold. These effects were lessened with increased CO2. Elevated CO2 increased polyamines in plants treated with CF air, but had no effect in the presence of ambient or enhanced O3 levels. Leaves harvested during peak flowering (37 days of treatment) showed O3-induced increases in Put and Spd at ambient CO2 concentrations. However, increased CO2 levels inhibited this response by blocking the O3-induced polyamine increase. Leaves harvested during the pod fill stage (57 days of treatment) showed no significant O3 or CO2 effects on polyamine levels. Our results demonstrate that current ambient O3 levels induce the accumulation of Put and Spd early in the growing season and that further increases in O3 could result in even greater polyamine increases. These results are consistent with a possible antiozonant function for polyamines. The ability of increased CO2 to protect soybeans from O3 damage, however, does not appear to involve polyamine accumulation. 相似文献
92.
Low frequency of extra-pair paternity in pied flycatchers revealed by DNA fingerprinting 总被引:8,自引:0,他引:8
Jan T. Lifjeld Tore Slagsvold Helene M. Lampe 《Behavioral ecology and sociobiology》1991,29(2):95-101
Summary Genetic parentage of 135 nestlings from 27 broods of polygynous and monogamous pied flycatchers Ficedula hypoleuca was analyzed by means of multilocus DNA fingerprinting. The minisatellite probe alpha-globin 3HVR detected approximately 12 scorable bands per fingerprint, and the proportion of bands shared between presumably unrelated adults averaged 0.22+0.08 SD. The fingerprints of 125 of the 135 nestlings made a complete match to those of their putative parents. In 4 nestlings a single mismatched band occurred, but since band sharing with both putative parents was high, the single mismatches were assumed to be caused by mutation. The 6 remaining nestlings had 5 or more mismatched bands each, low band-sharing proportions with their putative father and high band-sharing proportions with their putative mother. We thus conclude that they were all sired through extra-pair copulations (EPCs). Hence, only 4% of nestlings were sired through EPCs, and none resulted from intraspecific brood parasitism. One of the cuckolding males was identified, explaining all 5 mismatched bands in the nestling's fingerprint. Three of the illegitimate nestlings were from primary nests of polygynous males; 3 were from nests of monogamous males. The fact that many males in this study started to advertise for a second female in a distant territory several days before their first mate began egglaying, and still managed to secure almost exclusive paternity in their first brood, suggests that male polyterritoriality is not costly in terms of lost paternity. Common anti-cuckoddry tactics performed by male birds, like high rate of within-pair copulation and continuous mate-guarding thoughout the female's fertilizable period, do not seem to be important in pied flycatchers.Offprint requests to: J.T. Lifjeld 相似文献
93.
A Barba M A Camara S Navarro Garcia C Sanchez-Fresneda N Lopez de Hierro A Acebes 《Journal of environmental science and health. Part. B》1991,26(3):323-332
Residues of Bromopropylate were determine in artichokes, strawberries and beans after foliar spray of acaricide at two rates. The rates used were 1 g/l formulated product (normal recommended) and 1.5 g/l. The residue levels of bromopropylate in the three crops after 14 days were lower than 0.7 ppm and did not exceed the Maximum Residual Level (MRL) recommended by FAO. In the artichokes and strawberries, the total concentration of residues decreased by 50% of the initial level after 2-3 days. Only trace levels of the bromopropylate residues (less than 0.01 ppm) were detected in the "hearts" of the artichokes. Bromopropylate residues in the green beans were also less than 0.8 ppm after the first day of foliar spraying. The kinetic of degradation occurred in two different steps. In the first step (4-6 days) the dissipation of bromopropylate was faster whereas in the second step (7-14 days) the loss of residues was much slower. 相似文献
94.
95.
Taha R Ba-Omar M Pillay AE Roos G al-Hamdi A 《Journal of environmental monitoring : JEM》2001,3(4):417-420
The environmental impact of using petroleum-contaminated sand (PCS) as a substitute in asphalt paving mixtures was examined. An appreciable component of PCS is oily sludge, which is found as the dregs in oil storage tanks and is also produced as a result of oil spills on clean sand. The current method for the disposal of oily sludge is land farming. However, this method has not been successful as an oil content of < 1% w/w is required, and difficulty was encountered in reaching this target. The reuse of the sludge in asphalt paving mixtures was therefore considered as an alternative. Standard tests and environmental studies were conducted to establish the integrity of the materials containing the recycled sludge. These included physical and chemical characterization of the sludge itself, and an assessment of the mechanical properties of materials containing 0%, 5%, 22% and 50% oily sludge. The blended mixtures were subjected to special tests, such as Marshall testing and the determination of stability and flow properties. The experimental results indicated that mixtures containing up to 22% oily sludge could meet the necessary criteria for a specific asphalt concrete wearing course or bituminous base course. To maximize the assay from the recycled material, the environmental assessment was restricted to the 50% oily sludge mixture. Leachates associated with this particular mixture were assayed for total organic residue and certain hazardous metal contaminants. The results revealed that the organics were negligible, and the concentrations of the metals were not significant. Thus, no adverse environmental impact should be anticipated from the use of the recycled product. Our research showed that the disposal of oily sludge in asphalt paving mixtures could possibly yield considerable savings per tonne of asphalt concrete, and concurrently minimize any direct impact on the environment. 相似文献
96.
T. E. Lewis A. B. Crockett R. L. Siegrist 《Environmental monitoring and assessment》1994,30(3):213-246
Concerns over data quality have raised many questions related to sampling soils for volatile organic compounds (VOCs). This paper was prepared in response to some of these questions and concerns expressed by Remedial Project Managers (RPMs) and On-Scene Coordinators (OSCs). The following questions are frequently asked:
- Is there a specific device suggested for sampling soils for VOCs?
- Are there significant losses of VOCs when transferring a soil sample from a sampling device (e.g., split spoon) into the sample container?
- What is the best method for getting the sample from the split spoon (or other device) into the sample container?
- Are there smaller devices such as subcore samplers available for collecting aliquots from the larger core and efficiently transferring the sample into the sample container?
- Are certain containers better than others for shipping and storing soil samples for VOC analysis?
- Are there any reliable preservation procedures for reducing VOC losses from soil samples and for extending holding times?
- Open test pit or trench.
- Surface soils (<5 ft in depth).
- Subsurface soils (>5 ft in depth).
97.
Industrial and weathering inputs of Cd and Zn to the Sepetiba Bay and basin were assessed, based on production parameters obtained from local environment and industry authorities, and literature data. The results are compared with similar evaluations from other coastal regions and field data obtained in measuring Zn and Cd transport by rivers, direct run-off and atmospheric deposition in the region. Cadmium and zinc inputs to the bay increased by three orders of magnitude relative to pre-industrial fluxes and presently reach up to 1.6 and 180 tonnes per year for Cd and Zn, respectively, which represents a large input-to-area ratio, and explains the high concentration of these metals previously reported in the estuarine biota and sediments of Sepetiba Bay. Industrial activities, mainly metallurgical and chemical, comprise 94% and 84% of the total Cd and Zn inputs to the Bay. This figure identifies the point sources as being responsible for the environmental contamination and for regional poisoning risks. 相似文献
98.
99.
Else Marie Løbersli Eiliv Steinnes Magne Ødeg»rd 《Environmental monitoring and assessment》1990,15(2):111-129
Herbarium plants were used as a material to study possible long-term changes in mineral elements of forest plants. Plants from South Norway collected in the period 1870 to 1930 were compared to plants collected in 1982. Relative to mineral contents in plants from 1870 to 1930, the 1982 material showed elevated levels of Zn, Cd, Rb, K, Mn and Ti and decreased levels of Sr, B, Ca and Mo in some of the plant species analysed. Most of these differences may be explained by changes in the environmental conditions, due to differences in chemical composition of precipitation, accelerated soil acidification and subsequent increasing mineral weathering. Consequently analysis of herbarium plants seems to provide valuable information about preindustrial levels of mineral elements and seems to detect changes in mineral elements brought about by recent anthropogenic activity. 相似文献
100.
Excessive nitrate-N in south-central Minnesota ditches and streams is related to land-use change, and may be contributing to the development of the zone of hypoxia in the Gulf of Mexico. Intensive land-use (agricultural management) has progressively increased as subsurface drainage has improved crop productivity over the past 25 years. We have examined water at varying scales for delta18O and, nitrate-N concentrations. Additionally, analysis of annual peak flows, and channel geomorphic features provided a measure of hydrologic change. Laboratory and field results indicate that agricultural drainage has influenced riverine source waters, concentrations of nitrate-N, channel dimensions and hydrology in the Blue Earth River (BER) Basin. At the mouth of the BER shallow ground water comprises the largest source water component. The highest nitrate-N concentrations in the BER and tributaries typically occurred in May and June and ranged from 7-34 mg L(-1). Peak flows for the 1.01-2-yr recurrence intervals increased by 20-to-206% over the past 25 years. Geomorphic data suggest that small channels (ditches) were entrenched by design, whereas, natural that are disconnected from an accessible riparian corridor. Frequent access to a functioning riparian zone is important for denitrification. 相似文献