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1.
Degradation of ethinyl estradiol by nitrifying activated sludge 总被引:26,自引:0,他引:26
Vader JS van Ginkel CG Sperling FM de Jong J de Boer W de Graaf JS van der Most M Stokman PG 《Chemosphere》2000,41(8):1239-1243
Degradation of ethinyl estradiol (EE2) by nitrifying activated sludge was studied with micro-organisms grown in a reactor with feedback of sludge fed with only a mineral salts medium containing ammonium as the sole energy source. Ammonium was oxidised by this sludge at a rate of 50 mg NH4+ g(-1) DW h(-1). This activated sludge was also capable of degrading EE2 at a maximum rate of 1 microg g(-1) DW h(-1). Using sludge with an insignificant nitrifying capacity of 1 mg NH4+ g(-1) DW h(-1), no degradation of EE2 was detected. Oxidation of EE2 by nitrifying sludge resulted in the formation of hydrophilic compounds, which were not further identified. Most probably degradation by nitrifying sludge results in a loss of estrogenic activity, as hydroxylated derivatives of EE2 are known to have a substantially lower pharmacological activity than EE2. 相似文献
2.
Relatively few insects have invaded the marine environment, and only five species of sea skaters, Halobates Eschscholtz (Hemiptera: Gerridae), have successfully colonized the surface of the open ocean. All five species occur in the
Pacific Ocean, H. germanus White also occurs in the Indian Ocean, whereas H. micans Esch- scholtz is the only species found in the Atlantic Ocean. We sequenced a 780 bp long region of the mitochondrial cytochrome
oxidase subunit I gene (COI) for a total of 66 specimens of the five oceanic Halobates species. Our purpose was to investigate the genetic variation within species and estimate the amount of gene flow between
populations. We defined 27 haplotypes for H. micans and found that haplotype lineages from each of the major oceans occupied by this species are significantly different, having
sequences containing five to seven unique base substitutions. We conclude that gene flow between populations of H. micans inhabiting the Atlantic, Pacific, and Indian Ocean is limited and hypothesize that these populations have been separated
for 1 to 3 million years. Similarly, there may be limited gene flow between H. germanus populations found in the Pacific and Indian Ocean and between H. sericeus populations inhabiting the northern and southern parts of the Pacific Ocean. Finally, we discuss our findings in relation
to recent hypotheses about the influence of oceanic diffusion on the distribution and population structure of oceanic Halobates spp.
Received: 29 July 1999 / Accepted: 23 November 1999 相似文献
3.
Quanlu Wang Mark A. DeLuchi Daniel Sperling 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1275-1284
Alternative vehicular fuels are proposed as a strategy to reduce urban air pollution. In this paper, we analyze the emission Impacts of electric vehicles In California for two target years, 1995 and 2010. We consider a range of assumptions regarding electricity consumption of electric vehicles, emission control technologies for power plants, and the mix of primary energy sources for electricity generation. We find that, relative to continued use of gasoline-powered vehicles, the use of electric vehicles would dramatically and unequivocally reduce carbon monoxide and hydrocarbons. Under most conditions, nitrogen oxide emissions would decrease moderately. Sulfur oxide and particulate emissions would Increase or slightly decrease. Because other areas of the United States tend to use more coal in electricity generation and have less stringent emission controls on power plants, electric vehicles may have less emission reduction benefits outside California. 相似文献
4.
Emergency seed aid in Kenya: some case study insights on lessons learned during the 1990s 总被引:1,自引:0,他引:1
Sperling L 《Disasters》2002,26(4):329-342
This article reviews the effectiveness of seed-aid distributions in Kenya during the 1990s. It analyses the internal process and effects, i.e. the performance of the aid itself as well as the external process and effects, i.e. how seed-aid intervention affected farmers' broader agricultural management strategies. During the drought emergency of 1997, Kenyan farmers favourably judged many of the immediate seed-aid features such as crop and variety appropriateness and seed quality--even through the overarching goals of the seed assistance were muddled, ranging from assistance to the poor, to generalised gift-giving to stimulating progressive farming practice. However, the longer term analyses, drawn from recollections of a decade of relief activity, showed no concrete evidence that seed aid, per se, had strengthened their farming systems, nor that those who have received it once were less likely to receive it again. Thus, while seed aid has been promoted to lessen the effects of an 'acute' stress, drought, Kenyan farmers, in practice, have been experiencing much wider, 'chronic' seed system problems. This article ends by exploring this distinction between acute and chronic seed system stress and suggests a range of interventions appropriate to each. 相似文献
5.
Veiga LH Koifman S Melo VP Sachet I Amaral EC 《Journal of environmental radioactivity》2003,70(3):161-176
This paper aims to present an assessment of the environmental radiological exposure at a Brazilian area of high natural radiation and discusses the indoor radon exposure risk. A survey of inhabitant exposures arising from the inhalation of radon progeny and external gamma exposure was conducted in urban and rural areas of the Po?os de Caldas Plateau, which is recognized worldwide as a high natural radiation region. The results of this survey indicated that highest radiation exposure was restricted to the rural area of Po?os de Caldas. The radiation exposure in urban locations was quite similar to the values observed in normal background areas in some Brazilian counties. By the application of a constant relative risk model, an additional 20% in the lifetime risk of lung cancer mortality due to the exposure to radon progeny was estimated at Po?os de Caldas. It was also estimated that 16% of all lung cancer deaths at Po?os de Caldas county could be attributable to radon exposure. 相似文献
6.
Ferreira Leide Lene C. Abreu Marina P. Costa Camila B. Leda Paulo O. Behrens Maria Dutra dos Santos Elisabete Pereira 《Food and environmental virology》2022,14(2):120-137
Food and Environmental Virology - The use of natural resources for the prevention and treatment of diseases considered fatal to humanity has evolved. Several medicinal plants have nutritional and... 相似文献
7.
When shore crabs Carcinus maenas are transferred from 11 to 38 S at 11°C, new constant levels of hemolymph freezing points and of concentrations of Na, K, Ca, and Mg in the hemolymph are accomplished within 24h. From a decrease in serum protein and in serum free amino acids and an increase in the relative amounts of individual essential free amino acids in the body fluids of whole crabs, a participation of proteolytic activities and a transport of amino acids from hemolymph to cell is deduced; the stationary concentration of total intracellular free amino acids increases up to a nearly two-fold value, compared with the concentration in crabs remaining in diluted sea water. Also, the low molecular neutral sugars increase in whole crabs after high salinity stress, reaching values of more than two-fold initial concentrations within a period of 10 days. This increase is fully accounted for by a 6.7-fold increase in trehalose levels. The processes of increasing the concentrations of low molecular organic material seem to be slower than those of establishing new osmotic pressures in the hemolymph. The oxygen consumption decreases by 30 to 45% to new constant values within 8 to 12 h after the salinity change from 11 to 38, reflecting similar kinetics as the establishment of new osmotic pressures in the hemolymph. 相似文献
8.
Distribution of deep-water gorgonian corals in relation to benthic habitat features in the Northeast Channel (Atlantic Canada) 总被引:2,自引:0,他引:2
The distribution and abundance of deep-water gorgonian corals were investigated along 52 transects at 183–498 m depth in the Northeast Channel, between Georges Bank and Browns Bank in the northwest Atlantic, using a remotely operated vehicle and a towed video-camera system. Three species (Paragorgia arborea, Primnoa resedaeformis, and Acanthogorgia armata) were observed. Primnoa occurred on 35 transects below 196 m depth, with highest local abundance in stands of 104 colonies per 100 m2. Paragorgia was present on 21 transects deeper than 235 m, with highest local abundance of 49 colonies per 100 m2. Acanthogorgia was observed at only four transects between 231 m and 364 m, with a local maximum abundance of 199 colonies per 100 m2. The maximum abundance averaged for whole transects was 19.2 and 6.2 colonies per 100 m2 for Primnoa and Paragorgia, respectively. The corals were more common in the outer part of the channel along the shelf break and slope than on the shelf in the inner part. All three species showed a patchy distribution with no signs of competitive exclusion at any spatial scale. Transects with high abundance of corals were characterised by depths greater than 400 m, maximum temperatures less than 9.2°C, and a relatively high percentage coverage of cobble and boulder (more than 19% and 6%, respectively). High temperatures probably control the upper depth limit of the corals, and Primnoa seems to tolerate slightly higher temperatures than Paragorgia. Abundance of both species was negatively correlated with average temperature and positively with cobbles. Together, temperature, percentage cobble and salinity accounted for 38% of the variance of Primnoa. The comparable figure for Paragorgia was 15%. The observed distribution indicated that the abundance of coral is controlled by additional factors such as larger-scaled topographic features governing the current regimes and thus also the supply of food and larvae.Communicated by R. J. Thompson, St. Johns 相似文献
9.
We studied reproduction and larval development in three species of pedunculated barnacles with different depth distribution, that is, Scalpellum scalpellum (30–200 m), Ornatoscalpellum stroemii (100–1,600 m) and Arcoscalpellum michelottianum (64–5,190 m). Morphology, position and number of males in the female/hermaphrodite, type of larval development and the number and size of eggs were recorded. All three species have a pair of pocket-like receptacles, each of which can host only a single male in O. stroemii, up to five males in S. scalpellum and up to 12 males in A. michelottianum. Eggs and larvae were smallest in S. scalpellum, intermediately sized in O. stroemii and largest in A. michelottianum. Brood size was comparable for S. scalpellum and O. stroemii, but five times higher in A. michelottianum. The ratio for body/egg size is almost similar in S. scalpellum and A. michelottianum, but much smaller in O. stroemii. Both S. scalpellum and A. michelottianum have nauplii that spend upwards of 10 days in the plankton while the larvae of O. stroemii hatch as cyprids that settle soon after release. All these reproductive data indicate that O. stroemii invests considerably more in each propagule than the other two species. We hypothesize that the observed differences in reproductive system and mode of development in the three species represent adaptations to their different habitats. S. scalpellum are mainly transported by currents in the coastal sublittoral zone. O. stroemii is presumably spread by intermediate deep currents along the shelf and shelf-slope, while A. michelottianum occurs on seamounts and is probably transported by demersal currents over wide areas of inhospitable soft-bottoms. Our observations are in accordance with the general pattern that, egg-size and propagule-size are positively correlated to bathymetric and geographic distribution, and that the continental slope environment represents a high disturbance environment, where a short larval stage is an advantage. 相似文献
10.
Teien HC Salbu B Heier LS Kroglund F Rosseland BO 《Journal of environmental monitoring : JEM》2005,7(10):989-998
Aluminium (Al) toxicity is usually associated with acid rain and acidified freshwater systems. The present work demonstrates that acute fish mortality (50%) also occurs in moderate acidified salmon rivers during sea salt episodes. Furthermore, catchment liming was proved to be an efficient measure to counteract the fish toxicity. The impact of sea salt episodes on river water qualities and on Atlantic Salmon (Salmo salar L.) was studied in two rivers situated at the west coast of Norway. During February-May 2002, fish were kept in tanks and continually exposed to the changing water qualities. Changes in Al-species were followed using in situ fractionation techniques. During storm events and high sea salt deposition, the sea salt concentration increased (190 to 580 microM Cl), pH decreased (pH 5.3 to 4.6) and the concentration of low molecular mass (LMM) cationic Al-species (Al(i)) increased (0.7 to 3.0 microM) in the river. Subsequently, Al accumulated in fish gills (6 to 19 micromol g(-1) dw) causing ionoregulatory and respiratory failures as well as mortality. In water the concentration of LMM Al(i) stayed enhanced during four weeks, while the physiological stress responses in surviving fish remained high for a longer time (>eight weeks). To counteract Al toxicity, one of the tributary catchments had been limed four years earlier. Due to catchment liming (1000 kg ha(-1)) the water concentration of LMM Al(i)(<0.7 microM) and the Al accumulation in gills remained relatively low (<7 micromol g(-1) dw) during the storm and no fish mortality occurred. 相似文献