Analysis of stomach contents of the porbeagle shark (Lamna nasus Bonnaterre) in the northwest Atlantic   总被引：1，自引：0，他引：1  

Joyce  W. N.; Campana  S. E.; Natanson  L. J.; Kohler  N. E.; Pratt  H. L.  Jr; Jensen  C. F. 《ICES Journal of Marine Science》2002,59(6):1263-1269

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The development of a bloom of the dinoflagellate [Gyrodinium aureolum (Hulbert)] on the south-west Irish coast     

Raine  R.; Joyce  B.; Richard  J.; Pazos  Y.; Moloney  M.; Jones  K. J.; Patching  J. W. 《ICES Journal of Marine Science》1993,50(4):461-469

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On gas fluxes from small lakes and ponds     

Joyce Kwan  Peter A. Taylor 《Boundary-Layer Meteorology》1994,68(4):339-356

A semi-empirical model for estimating gas fluxes at the air-water interface in a neutrally stratified atmosphere is presented. Gas transfer velocity is assumed to depend on local friction velocity, whose variation with over-water fetch is estimated from Walmsleyet al.'s (1989) Guidelines. As guidance for limnologists estimating CO₂ and CH₄ fluxes from lakes and ponds in the Hudson Bay Lowlands region, we present model results of the variation of gas transfer velocity with over-water fetch,k(x), for comparison with the customary constant valuek ₀. Gas fluxes are estimated over well mixed, circular and elliptical lakes and ponds. The results of accounting for fetch dependence, wind direction, pond shapes and sizes lead to correction factors to fluxes obtained withk ₀. Recent studies of gas transfer velocity for gases of low solubility from lakes are reviewed, and the problem of time averaging on quantities determined from experimental measurements is also discussed.  相似文献   

Transient induction of 7-ethoxyresorufin-O-deethylase (EROD) activity by medium change in the rainbow trout liver cell line, RTL-W1.     

H Segner  A Behrens  E M Joyce  K Schirmer  N C Bols 《Marine environmental research》2000,50(1-5):489-493

Cytochrome P4501A (CYP1A) metabolizes a wide array of lipophilic xenobiotics. In fish liver, CYP1A is constitutively expressed at low levels, but xenobiotics can strongly induce CYP1A expression via a receptor-mediated pathway. While induction of hepatic CYP1A in teleosts by xenobiotics is well investigated, very little is known on the regulation of constitutive CYP1A expression and its induction by factors other than xenobiotics. In the present study we show that in the rainbow trout liver cell line, RTL-W1, CYP1A-catalyzed 7-ethoxyresorufin-O-deethylase (EROD) activity can be induced by a change of the culture medium, in the absence of xenobiotics. The increase in cellular EROD levels is of transient nature. Experiments with cell incubation solutions supplemented with various medium components indicate that photooxidized tryptophan is the agent causing the increase of EROD activity after medium change.  相似文献   

Effects of uncertainty in rock-physics models on reservoir parameter estimation using seismic amplitude variation with angle and controlled-source electromagnetics data     

Jinsong Chen  Thomas A. Dickens 《Geophysical Prospecting》2009,57(1):61-74

This paper investigates the effects of uncertainty in rock-physics models on reservoir parameter estimation using seismic amplitude variation with angle and controlled-source electromagnetics data. The reservoir parameters are related to electrical resistivity by the Poupon model and to elastic moduli and density by the Xu-White model. To handle uncertainty in the rock-physics models, we consider their outputs to be random functions with modes or means given by the predictions of those rock-physics models and we consider the parameters of the rock-physics models to be random variables defined by specified probability distributions. Using a Bayesian framework and Markov Chain Monte Carlo sampling methods, we are able to obtain estimates of reservoir parameters and information on the uncertainty in the estimation. The developed method is applied to a synthetic case study based on a layered reservoir model and the results show that uncertainty in both rock-physics models and in their parameters may have significant effects on reservoir parameter estimation. When the biases in rock-physics models and in their associated parameters are unknown, conventional joint inversion approaches, which consider rock-physics models as deterministic functions and the model parameters as fixed values, may produce misleading results. The developed stochastic method in this study provides an integrated approach for quantifying how uncertainty and biases in rock-physics models and in their associated parameters affect the estimates of reservoir parameters and therefore is a more robust method for reservoir parameter estimation.  相似文献   

'…the world was getting smaller': women, agoraphobia and bodily boundaries     

Joyce Davidson 《Area》2000,32(1):31-40

Summary Drawing on individual and group interviews with agoraphobic women, this paper explores sufferers' accounts of agoraphobia as entailing apparent dysfunctions in spatial awareness. In particular, it examines the effects of agoraphobic anxiety on the lived boundaries of body and self and relates this to agoraphobics' contrasting experiences of the relative 'security' of the home and the unheimlich and disturbing architecture of the shopping mall.  相似文献   

Precolumbian jade: New geological and cultural interpretations. Frederick W. Lange (Editor), 1993, University of Utah Press,xix + 378 pp., $45.00 (clothbound)     

Rosemary A. Joyce 《Geoarchaeology》1994,9(3):259-261

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Solar Models with Dynamic Screening and Early Mass Loss Tested by Helioseismic,Astrophysical, and Planetary Constraints     

Suzannah R. Wood  Katie Mussack  Joyce A. Guzik 《Solar physics》2018,293(7):111

The faint young Sun paradox remains an open question. Presented here is one possible solution to this apparent inconsistency, a more massive early Sun. Based on the conditions on early Earth and Mars, a luminosity constraint is set as a function of mass. We examine helioseismic constraints of these alternative mass-losing models. Additionally, we explore a dynamic electron screening correction in an effort to improve helioseismic agreement in the core of the early mass-losing model.  相似文献   

Sea level and paleotemperature records from a mid-Holocene reef on the North coast of Java, Indonesia     

Karem Azmy  Evan Edinger  Joyce Lundberg  Wilfredo Diegor 《International Journal of Earth Sciences》2010,99(1):231-244

Mid-Holocene age fossil-fringing reefs occur along the tectonically stable north coast of Java, Indonesia, presenting an opportunity for sea level and paleoclimate reconstruction. The fossil reef at Point Teluk Awur, near Jepara, Central Java, contains two directly superposed horizons of Porites lobata microatolls. Corals in the lower horizon, 80 cm above modern sea level, yielded Uranium series dates of 7090 ± 90 year BP, while corals in the upper horizon at 1.5 m grew at 6960 ± 60 year BP. These dates match the transgressive phase of regional sea-level curves, but suggest a mid-Holocene highstand somewhat older than that recorded on mid-Pacific islands. Paleotemperature was calibrated using Sr/Ca and δ¹⁸O values of a modern P. lobata coral and the locally measured sea surface temperature (SST), yielding SST–Sr/Ca and SST–δ¹⁸O calibration equations [T _Sr/Ca = 91.03–7.35(Sr/Ca) and T_{d¹⁸ \textO} T_{{\delta^{18} {\text{O}}}}  = −3.77 to −5.52(δ¹⁸O)]. The application of the local equations to Sr/Ca and δ¹⁸O measurements on these corals yielded a range of temperatures of 28.8 ± 1.7°C, comparable to that of the modern Java Sea (28.4 ± 0.7°C). A paleo-salinometer [Δδ¹⁸O = ∂δ¹⁸O/∂T ( T_{d¹⁸ \textO} T_{{\delta^{18} {\text{O}}}}  − T _Sr/Ca)], re-calculated using the local parameters, also suggests Java Sea mid-Holocene paleosalinity similar to modern values.  相似文献   

Association of specific organic matter compounds in size fractions of soils under different environmental controls     

Joyce S. ClementeAndre J. Simpson  Myrna J. Simpson 《Organic Geochemistry》2011,42(10):1169-1180

Inherent chemical recalcitrance and association of organic matter (OM) with minerals are mechanisms responsible for the long term preservation of OM in soils. The structural characteristics of OM are also believed to control specific interactions between OM and soil minerals. However, the extent of the relationship between recalcitrance and mineral protection and the specificity of these chemically driven interactions are not clearly understood at the molecular level. To measure chemical patterns of OM sequestration in sand-, silt-, clay-size and light fractions, we analyzed three soils, which mainly differed in carbon content and overlying vegetation, but have similar clay mineralogy, using biomarker analysis and nuclear magnetic resonance (NMR). Despite differences in environmental controls, long chain aliphatic compounds generally accumulated in the fine fractions of all soils. This accumulation is likely due to the strong interaction between recalcitrant forms of OM and soil minerals. For example, polymethylene and >C₂₀ organic acids accumulated in fine fractions, while lignin-derived phenols were protected from oxidation in silt-size fractions. Diffusion edited solution state ¹H NMR suggested that contributions from microbial-derived OM was greater in finer fractions, which is likely due to the accumulation of microbial-derived compounds or higher microbial activity in clay micro-sites. Our data suggest that, for these Prairie soils, the specific structure of OM and not environmental factors is responsible for long term preservation of OM in mineral fractions. Further research is necessary to understand the interplay between these preservation mechanisms such that the long term fate of OM can be further elucidated.  相似文献