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111.
Proposal for applying a component-based mixture approach for ecotoxicological assessment of fracturing fluids 总被引:2,自引:2,他引:0
Janet Riedl Stefanie Rotter Sonja Faetsch Mechthild Schmitt-Jansen Rolf Altenburger 《Environmental Earth Sciences》2013,70(8):3907-3920
Hydraulic fracturing is increasingly being used to produce gas from unconventional resource sites for energy supply. Therefore, concerns about risks of this technology related to human health and the environment have to be addressed. Among the major issues is the potential contamination of surrounding water systems by chemical additives used in fracturing fluids. In this study, the ecotoxicological hazards of fracturing fluids, both, their individual components (chemicals) as well as their mixtures (product) were assessed using a component-based mixture approach. For five exemplary fracturing fluids, 40–90 wt% of the contained substances could unambiguously be defined in their chemical identity. The concentrations used in the applied fluid mixture were considered as (maximum) exposure concentrations. For components with mass fractions between 10 and 74 wt%, the effect concentrations for acute and chronic toxicity of fish, daphnia and algae were retrieved from experimental databases and through predictive modeling. The hazard indices calculated from the ratio of exposure to effect concentration were >1 for all fracturing fluids, using different scenarios. This indicated a hazard from the undiluted fracturing fluids. The assessment framework presented in this study allows for dealing with data gaps and uncertainties in a tiered fashion and in particular accommodates for combined effects resulting from chemical mixtures. It might be employed for ecotoxicological risk assessment of products containing chemical mixtures and optimization of their environmental performance. 相似文献
112.
Janet Speake 《The Cartographic journal》2013,50(4):345-355
The use of qualitative research techniques in a largely quantitative cartographic domain is opening up myriad ways to explore users’ engagements technologies of navigation. This study draws on young UK-based students’ real words and life experiences as they engage with Satellite Navigation and other wayfinding technologies during first-time visits to new places to reflect on the nature of the changing relationships between self, navigational object, space and place. 相似文献
113.
114.
Real-time PCR and NASBA for rapid and sensitive detection of Vibrio cholerae in ballast water 总被引:2,自引:0,他引:2
Fykse EM Nilsen T Nielsen AD Tryland I Delacroix S Blatny JM 《Marine pollution bulletin》2012,64(2):200-206
Transport of ballast water is one major factor in the transmission of aquatic organisms, including pathogenic bacteria. The IMO-guidelines of the Convention for the Control and Management of Ships' Ballast Water and Sediments, states that ships are to discharge <1 CFU per 100 ml ballast water of toxigenic Vibrio cholerae, emphasizing the need to establish test methods. To our knowledge, there are no methods sensitive and rapid enough available for cholera surveillance of ballast water. In this study real-time PCR and NASBA methods have been evaluated to specifically detect 1 CFU/100ml of V. cholerae in ballast water. Ballast water samples spiked with V. cholerae cells were filtered and enriched in alkaline peptone water before PCR or NASBA detection. The entire method, including sample preparation and analysis was performed within 7 h, and has the potential to be used for analysis of ballast water for inspection and enforcement control. 相似文献
115.
Nyctiphanes australis (Euphausiacea) and an upwelling plume in western Cook Strait,New Zealand 总被引:1,自引:1,他引:0
Quantitative data are presented on the distribution of adult and larval stages of the euphausiid Nyctiphanes australis G. O. Sars, in western Cook Strait, New Zealand, an area influenced by an upwelling plume. The behaviour of N. australis in the Kahurangi Point region at different stages of its life history appears to ensure its maintenance, in general, over the continental shelf on an upwelling coast. Population structure at the source of the upwelling near Kahurangi Point differed from that in regions “down stream” from the plume. Nyctiphanes australis was most abundant at the “downstream” eastern end of the upwelling plume, and the evidence suggesting that the dense populations there may be resident is discussed. Possible reasons for low densities of furcilia II and III stages in the eastern plume region are considered. 相似文献
116.
Janet M. Bradford‐Grieve 《新西兰海洋与淡水研究杂志》2013,47(4):781-793
Two species of benthopelagic calanoid Copepoda, Neoscolecithrix cf. magna (Grice, 1972) and N. ornata n. sp., are described from the upper slope off North Cape, New Zealand. Neoscolecithrix ornata is distinguished from other species of Neoscolecithrix Canu, 1896 s.s. that have a female leg 5 terminal segment with 4 spines (2 terminal and 1 on each border) principally by the transverse row of long, fine spines on the female genital double somite; and by the more squat terminal segment of leg 5 (length/width ratio about 3.7). This is the second time Neoscolecithrix has been recorded from New Zealand. A new genus, Cenognatha n. gen., is distinguished from Neoscolecithrix principally because: rostrum short (bearing 2 filaments); mandibu‐lar gnathobase masticatory margin with slender dorsal spinulose seta; maxilla endite 1 with 5 well‐developed setae, endite 3 without brush‐like sensory seta, endopod usually with 3 long worm‐like sensory setae and 5 brush‐like setae; posterodistal border of basis of legs 1–3 without spines; distal segment of female leg 5 and its basis subequal in length; male leg 5 of similar lengths on both sides (styliform on right), endopod present at least on 1 side, 1‐segmented and spine‐like on right. 相似文献
117.
Janet M. Bradford‐Grieve 《新西兰海洋与淡水研究杂志》2013,47(4):941-949
Xantharus Andronov, 1981 is reported, for the first time from New Zealand, from the upper slope (306 m) off the southeastern coast of North Island (41°04.10′S, 176°22.05′E). Xantharus cryeri n. sp. females differ from the three known species by a combination of characters: antennules that extend to the distal border of pedigerous somite 2; ancestral segment XVIII of the antennule with 1 seta; mandible basis with 3 setae; maxilla endite 1 with 5 setae; leg 1 basis with inner distal border lined with small spinules; and leg 5 is squat, with all segments as long as wide and the 2 terminal spine‐like extensions of the terminal segment approximately as long as the articulated, inner, subterminal spine. 相似文献
118.
Abstract Greenshell? mussels (Perna canaliculus Gmelin), scallops (Pecten novaezealandiae Reeve), and Pacific oysters (Crassostrea gigas Thunberg) were fed with a New Zealand strain of mass cultured Ostreopsis siamensis Schmidt (for 27 and 84 h and with 1.5 × 106 or 8.6 × 106 cells, respectively) under laboratory conditions. The microalgal cells contained 0.3 pg palytoxin equivalents cell–1 (as determined by the haemolysis neutralisation assay (HNA) of Bignami (1993)) and extracts of these cells were toxic to mice after intraperitoneal injection. No palytoxin‐like material was detected either in the hepatopancreas or the muscle and roe of mussels fed O. siamensis. Oysters contained detectable amounts of toxin in hepatopancreas muscle, and roe while higher concentrations were present in the hepatopancreas of scallops. Extracts of control shellfish (tested biotoxin free and not fed O. siamensis) were toxic to mice, and there was no definitive evidence that feeding shellfish with O. siamensis at the levels employed in the present experiment increased the toxicity of shellfish tissue extracts to mice. 相似文献
119.
Michael C. Kelley Ronald R. Ilma Michael Nicolls Philip Erickson Larisa Goncharenko Jorge L. Chau Nestor Aponte Janet U. Kozyra 《Journal of Atmospheric and Solar》2010,72(4):285-291
In November 2004, a major magnetic storm occurred, a lengthy portion of which was recorded by the Upper Atmospheric Radar Chain. On the 9th and 10th, the Jicamarca Radar detected the highest magnitude penetrating electric fields (±3 mV/m) and vertical drifts (±120 m/s) ever seen at this premiere facility. These large and variable drifts were highly correlated with the interplanetary magnetic and electric fields and created a double F layer on the dayside and unusual TEC behavior throughout the low-latitude zone. These solar wind-induced drifts both suppressed and generated irregularities at the magnetic equator at different times. Large-scale thermospheric disturbances were generated by high-latitude heating and tracked through the middle- to low-latitude zones where both parallel and perpendicular plasma drifts created major ionospheric changes. The auroral oval was located at a magnetic L shell of about three for many hours. 相似文献
120.
Yoko Furukawa Janet L Watkins Jinwook Kim Kenneth J Curry Richard H Bennett 《Geochemical transactions》2009,10(1):2-11