Characterization and induction of cytochrome P-450 in the rainbow trout kidney     

Maija Pesonen  Tommy Andersson  Lars Frlin 《Marine environmental research》1985,17(2-4)

Cytochrome P-450 monooxygenases catalyze the biotransformation of a great variety of foreign, as well as endogenous, lipid-soluble compounds to more water-soluble products. As in mammals, highest concentration of cytochrome P-450 in fish is found in the liver. However, previous studies have indicated that fish kidney contains relatively high cytochrome P-450-mediated activities.^1,2 We have therefore prepared and characterized subcellular fractions from the kidney of rainbow trout suitable for studies on cytochrome P-450-dependent reactions. Furthermore, as in the liver, several cytochrome P-450-mediated reactions in the kidney were induced following treatment of the fish with β-naphthoflavone.  相似文献   

Feeding of Plaice (Pleuronectes Platessa L.) and COD (Gadus Morhua L.) Larvae     

Nordeng  Hans; Bratland  Per 《ICES Journal of Marine Science》1971,34(1):51-57

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Mafic plutonic rocks in a continental‐arc setting: geochemistry of 1.87–1.78 Ga rocks from south‐central Sweden and models of their palaeotectonic setting     

Henrikki Rutanen  Ulf B. Andersson 《Geological Journal》2009,44(3):241-279

Mafic intrusive rocks (1.79–1.78 Ga) of the Transscandinavian Igneous Belt (TIB) and the c. 1.87 Ga Hedesunda Igneous Complex in the Fennoscandian Shield of south‐central Sweden were studied using whole‐rock and isotope geochemistry. Rock types vary from gabbros/norites (and leucogabbros) to quartz diorites, with Mg# between 76 and 49, and wt% SiO₂ between 43.6 and 59.7, indicating some variation in evolutionary levels and variable cumulus components. Geochemical signatures are calc‐alkaline to shoshonitic, large ion lithophile elements and light rare earth elements enriched and high‐field strength elements depleted of continental‐arc type. ε_Nd(t) ranges between +1.0 and +2.7, and ⁸⁷Sr/⁸⁶Sr(t) between 0.7020 and 0.7038. There is no systematic correlation between chemical parameters and isotope ratios. These isotopic data overlap with other mafic plutonic TIB rocks; samples from the Dala Province (DP) tend to overlap with the c. 1.7 Ga basic Dala lavas of TIB at slightly elevated relative Sr/Nd ratios. With two exceptions, the ε_Nd(t) of +1 to +2 conform to an isotopically ‘mildly depleted’ source, typical for mafic TIB rocks and many Svecofennian rocks in the region. Reported values above ε_Nd(t) +2.0 are scarce in the TIB. Mantle sources represent depleted mantle wedge material that was enriched by fluids/melts not long before (T_DM c. 2.0 Ga), that is during subduction in the preceding Svecofennian (2.0–1.87 Ga) and/or during the TIB‐0&1 event (1.85–1.78 Ga). The palaeotectonic settings inferred are active continental margins; N–S‐directed convergence at 1.87 Ga and E–W‐directed at 1.79–1.78 Ga. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

U–Pb TIMS age constraints on the evolution of the Neoproterozoic Meatiq Gneiss Dome,Eastern Desert,Egypt     

Arild Andresen  Mohamed Ali Abu El-Rus  Per Inge Myhre  Gamal Y. Boghdady  Fernando Corfu 《International Journal of Earth Sciences》2009,98(3):481-497

Ages are used to constrain the temporal evolution of the Meatiq Gneiss Dome, Eastern Desert, Egypt, by dating (ID-TIMS) pre-, syn-, and post-tectonic igneous rocks in and around the dome. The Um Ba’anib Orthogneiss, comprising the deepest exposed structural levels of the dome, has a crystallization age of 630.8 ± 2 Ma. The overlying mylonites are interpreted to be a thrust sheet/complex (Abu Fannani Thrust Sheet) of highly mylonitized metasediments (?), migmatitic amphibolites, and orthogneisses with large and small tectonic lenses of less-deformed intrusives. Two syn-tectonic diorite lenses in this complex have crystallization ages of 609.0 ± 1.0 and 605.8 ± 0.9 Ma, respectively. The syn-tectonic Abu Ziran diorite, cutting across the tectonic contact between mylonite gneisses of the Abu Fannani Thrust Sheet and a structurally overlying thrust sheet of eugeoclinal rocks (“Pan-African nappe”), has a magmatic emplacement age of 606.4 ± 1.0 Ma. Zircons from a gabbro (Fawakhir ophiolite) within the eugeoclinal thrust sheet yielded a crystallization age of 736.5 ± 1.2 Ma. The post-tectonic Fawakhir monzodiorite intrudes the ophiolitic rocks and has an emplacement age of 597.8 ± 2.9 Ma. Two other post-tectonic granites, the Arieki granite that intrudes the foliated Um Ba’anib Orthogneiss, and the Um Had granite that cuts the deformed Hammamat sediments, have emplacement ages of 590 ± 3.1 and 596.3 ± 1.7 Ma, respectively. We consider formation of the Meatiq Gneiss Dome to be a young structural feature (<631 Ma), and our preferred tectonic interpretation is that it formed as a result of NE–SW shortening contemporaneous with folding of the nearby Hammamat sediments around 605–600 Ma, during oblique collision of East and West Gondwana.  相似文献   

The effect of river liming on the accumulation of radiocesium in sediments from a down stream lake     

Per Kristian Egeberg 《Aquatic Sciences - Research Across Boundaries》2000,62(1):68-78

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Composition of the water accommodated fractions as a function of exposure times and temperatures   总被引：1，自引：0，他引：1  

Faksness LG  Brandvik PJ  Sydnes LK 《Marine pollution bulletin》2008,56(10):1746-1754

The water accommodated fractions (WAFs) of nine oils in seawater have been studied. The oils range from light condensate to heavy crude, and include one highly biodegraded oil and one very wax rich oil. This study has identified large variations in the chemical composition of WAFs, depending on oil type, temperature, and mixing time. Experiments at different temperatures (2-13 °C) showed that it takes longer time to reach equilibrium at the lowest temperatures, and that this varies for the different oil types. Oils with higher pour point (wax rich oils) need a longer time to establish WAF in equilibrium than oils with lower pour points (naphthenic oils). At 13 °C a mixing time of 48 h, as recommended in standard procedures, seems to be sufficient for asphalthenic and paraffinic oils. The results demonstrated that for WAF prepared from an unknown oil, or at lower temperatures, different mixing times should be tested. Since the WAF often is used in toxicity testing, the toxicity might be underestimated if the mixing time is too short.  相似文献   

Clustering of galaxies around radio quasars at 0.5≤z≤0.8     

Margrethe Wold  Mark Lacy  Per B. Lilje  Stephen Serjeant 《Monthly notices of the Royal Astronomical Society》2000,316(2):267-282

We have observed the galaxy environments around a sample of 21 radio-loud, steep-spectrum quasars at 0.5≤ z ≤0.82, spanning several orders of magnitude in radio luminosity. The observations also include background control fields used to obtain the excess number of galaxies in each quasar field. The galaxy excess was quantified using the spatial galaxy–quasar correlation amplitude, B _gq, and an Abell-type measurement, N _0.5. A few quasars are found in relatively rich clusters, but on average, they seem to prefer galaxy groups or clusters of approximately Abell class 0. We have combined our sample with literature samples extending down to z ≈0.2 and covering the same range in radio luminosity. By using the Spearman statistic to disentangle redshift and luminosity dependences, we detect a weak, but significant, positive correlation between the richness of the quasar environment and the radio luminosity of the quasar. However, we do not find any epoch dependence in B _gq, as has previously been reported for radio quasars and galaxies. We discuss the radio luminosity–cluster richness link and possible explanations for the weak correlation that is seen.  相似文献   

Coastal profile response to sea level rise: a process‐based approach     

Troels Aagaard  Per Sørensen 《地球表面变化过程与地形》2012,37(3):354-362

Prevailing ideas and calculations of coastal response to sea level rise (SLR) are often based on the Bruun model (Bruun P., Sea‐level rise as a cause of shore erosion, Journal Waterways Harbors Division, ASCE 88 : 117–130, 1962) that predicts upward and landward transfer of an equilibrium profile during SLR through offshore sediment transport on the shoreface. The model is based on a number of assumptions of questionable validity as well as outdated concepts on how sediment is transported across the shoreface. This contribution takes a numerical modelling approach that is based on first‐order processes contributing to the movement of sediment across the shoreface. Using a wave transformation model that predicts hydrodynamic processes driving cross‐shore sediment transport and an energetics‐based model for the coupling between hydrodynamics and sediment transport, we show that cross‐shore sediment transport is mainly onshore directed at the boundary between the lower and the upper shoreface, in agreement with the model proposed by Davidson‐Arnott (Conceptual model of the effects of sea level rise on sandy coasts, Journal of Coastal Research 21 : 1166–1172, 2005). The transition from onshore to offshore directed transport is located well within the surf zone and with a rising sea level this transition point becomes displaced landward and upward. Tests also show that substrate slope is of fundamental importance to the manner in which beaches react to rising sea level. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Chronic exposure of adults and embryos of Pandalus borealis to oil causes PAH accumulation, initiation of biomarker responses and an increase in larval mortality     

Renée Katrin Bechmann  Bodil Katrine Larsen  Ingrid Christina Taban  Per Møller 《Marine pollution bulletin》2010,60(11):2087-2098

Adult shrimps (Pandalus borealis) and their embryos were exposed to an oil-water dispersion (OWD) at concentrations of 0.015, 0.06 and 0.25 mg/L using a continuous flow system. Lysosomal membrane stability was analysed in haemocytes using the neutral red retention assay and an alkaline unwinding assay was used to measure DNA damage in hepatopancreas tissue. Exposure to oil induced concentration and time dependent biomarker responses in adult shrimps together with the accumulation of PAH in their tissues. Oil exposure of shrimp embryos caused increased mortality in the resultant larvae, even if the larvae were kept in clean water after hatching. There were minor differences observed in larval stage development times in the first part of the experiments. The fatty acid composition of embryos exposed to oil was different to that of non-exposed larvae. PAH tissue concentration and biomarker responses correlated to the reduced survival of the shrimp larvae.  相似文献   

Algorithms for GPS operation indoors and downtown   总被引：6，自引：0，他引：6  

Nainesh Agarwal  Julien Basch  Paul Beckmann  Piyush Bharti  Scott Bloebaum  Stefano Casadei  Andrew Chou  Per Enge  Wungkum Fong  Neesha Hathi  Wallace Mann  Anant Sahai  Jesse Stone  John Tsitsiklis  Benjamin Van Roy 《GPS Solutions》2002,6(3):149-160

The proliferation of mobile devices and the emergence of wireless location-based services has generated consumer demand for availability of GPS in urban and indoor environments. This demand calls for enhanced GPS algorithms that accommodate high degrees of signal attenuation and multipath effects unique to the "urban channel." This paper overviews the market for location-based services and discusses algorithmic innovations that address challenges posed by urban environments. Electronic Publication  相似文献