Induction of zona radiata and vitellogenin genes in estradiol and nonylphenol exposed male sheepshead minnows (Cyprinodon variegatus)   总被引：1，自引：0，他引：1  

Knoebl I  Hemmer MJ  Denslow ND 《Marine environmental research》2004,58(2-5):547-551

Several genes normally induced by estradiol (E(2)) in female fish, those for vitellogenins (VTGs) and zona radiata proteins (ZRPs), are also inducible in males exposed to estrogenic chemicals. Male sheepshead minnows (SHM) were exposed to both E(2) and para-nonylphenol (NP), at several doses and times to determine a dose-response. Quantitative real time PCR was used to measure mRNA for VTG1, VTG2, ZRP2 and ZRP3. Both E(2) and NP elicited a dose-response increase in all of the mRNAs tested. Exposure to both chemicals resulted in VTG2 expression at about a 10-fold lower level than VTG1, and ZRP2 expression at a lower level than ZRP3.  相似文献   

Effects of acoustic alarms, designed to reduce small cetacean bycatch in gillnet fisheries, on the behaviour of North Sea fish species in a large tank     

Kastelein RA  van der Heul S  van der Veen J  Verboom WC  Jennings N  de Haan D  Reijnders PJ 《Marine environmental research》2007,64(2):160-180

World-wide many cetaceans drown incidentally in fishing nets. To reduce the unwanted bycatch in gillnets, pingers (acoustic alarms) have been developed that are attached to the nets. In the European Union, pingers will be made compulsory in some areas in 2005 and in others in 2007. However, pingers may effect non-target marine fauna such as fish. Therefore in this study, the effects of seven commercially-available pingers on the behaviour of five North Sea fish species in a large tank were quantified. The species tested were: sea bass (Dicentrarchus labrax), pout (Trisopterus luscus), thicklip mullet (Chelon labrosus), herring (Clupea harengus), and cod (Gadus morhua). The fish were housed as single-species schools of 9-13 individuals in a tank. The behaviour of fish in quiet periods was compared with their behaviour during periods with active pingers. The results varied both between pingers and between fish species. Sea bass decreased their speed in response to one pinger and swam closer to the surface in response to another. Thicklip mullet swam closer to the bottom in response to two pingers and increased their swimming speed in response to one pinger. Herring swam faster in response to one pinger, and pout and cod (close relatives) showed no behavioural responses to any of the pingers. Of the seven pingers tested, four elicited responses in at least one fish species, and three elicited no responses. Whether similar responses would be elicited in these fish species in the wild, and if so, whether such responses would influence the catch rate of fisheries, cannot be derived from the results of this study. However, the results indicate the need for field studies with pingers and fish. Based on the small number of fish species tested, the present study suggests that the higher the frequency of a pinger, the less likely it is to affect the behaviour of marine fish.  相似文献   

Progressive deformation of an evaporite-bearing accretionary complex: SeaMARC I,SeaBeam and piston-core observations from the Mediterranean Ridge     

Kim A. Kastens  Nancy A. Breen  Maria B. Cita 《Marine Geophysical Researches》1992,14(4):249-298

The Mediterranean Ridge is an arcuate ridge of deformed sediment caught up in the convergent plate margin between the African plate and the Aegean. An intensive campaign of SeaMARC I and SeaBeam surveys followed by piston coring has been conducted along the contact between undeformed turbidites of the Sirte Abyssal Plain and folded and faulted sediments of the Mediterranean Ridge. Along the outer edge of the Ridge, surficial sediments have been deformed into sinusoidal ridges and troughs (wavelengths 0.5–2 km, amplitude 20–150 m), which we interpret as folds. In plan view, the ridge and the trough fabric parallels the NW-SE trending regional contours, suggesting that the folds formed in response to compression orthogonal to the Mediterranean Ridge. The outermost ridge is shedding a debris apron out onto the abyssal plain, implying that uplift and deformation are ongoing. We show that the geometry of the outermost folds can be produced by elastic bending of a packet of 5–10 relatively strong layers, each 10–20 m thick, interbedded between weaker layers; we equate the strong layers with gypsum beds in the Messinian upper evaporites. Folding the seafloor from a flat layer into the observed ridge and trough topography would shorten the layer by less than 2%. Two percent shortening (equals two percent thickening) is insufficient to create the observed relief of the Mediterranean Ridge even if the entire sediment column down to basement were involved; we infer that additional shortening/thickening is accommodated by thrust faulting above a decollement at the top of the Messinian salt layer. At distances > 15 km from the deformation front and more than 500 m from the abyssal plain, sharp-edged, fine-grained side-scan lineations with very little vertical relief cut across the kilometer-scale ridge and trough topography. These fine-grained lineations fall in two groups trending N/S to NNE/SSW and ~ENE. We interpret these lineaments as traces of conjugate strike-slip faults formed in the same compressional regime which formed the NW/SE trending folds. The onset of strike-slip faulting may coincide with the cessation of imbricate thrust fan development above the initial salt-controlled decollement surface. The following characteristics of the Mediterranean Ridge are attributed to the presence of evaporites in the incoming sedimentary section: (1) initial deformation by folding rather than thrust faulting; (2) narrow taper; (3) rapid rate of outward growth; (4) karstification.  相似文献   

Changes in topography and vegetation near gaps in a protective foredune     

Karl F. Nordstrom  JeanMarie Hartman  Amy L. Freestone  Mark Wong  Nancy L. Jackson 《Ocean & Coastal Management》2007,50(11-12):945-959

Data gathered on a foredune on a nourished beach reveal the relationships between topography and plant communities at gaps in the dune crest. Sand inundation at gaps allows plants in some portions of the dune to rejuvenate to earlier successional stages, while an increase in richness occurs in other portions. Ammophila breviligulata can create an initial dune ridge, colonize new areas of bare sand within the dune field, facilitate growth of other species, and provide a natural alternative to fencing in managing gaps. Foredune mobility can be considered a positive factor if beach width and dune volume provide adequate protection.  相似文献   

Growth and reproductive dynamics of adult female Dungeness crabs (Cancer magister) in northern California     

Hankin  David G.; Diamond  Nancy; Mohr  Michael S.; Ianelli  James 《ICES Journal of Marine Science》1989,46(1):94-108

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Apatite-rich pyrometamorphic rocks from Suweileh area,Jordan     

Nancy Al-Ajarmeh  Hani Khoury 《Arabian Journal of Geosciences》2018,11(17):520

Representative samples from the upper Cretaceous pyrometamorphic rocks from Suweileh area were investigated by using XRD, XRF, SEM/EDS, and microprobe techniques. Suweileh area is characterized by the presence of varicolored marble (dominated by green apatite-rich rocks) overlying bituminous marl and silicified limestone-phosphorite beds. The bituminous rocks are enriched with P, S, and F in addition to reduced sensitive trace elements that were inherited later by their metamorphic equivalents. The rocks were affected by severe tectonism that produced intensive fracturing which facilitated the chemical leaching. The mineralogy of the varicolored marble from Suweileh area is equivalent to Daba-Siwaqa and Maqarin areas in central and north Jordan. High-temperature and low-temperature groups of minerals were recognized. The first group is the result of pyrometamorphism produced from the spontaneous combustion of bituminous marl. The metamorphism was contemporaneous with tectonism of the Rift Valley. The second secondary group of minerals is the result of alteration by high alkaline waters followed by precipitation along the weakness zones. A hyperalkaline circulating water similar to the current issuing waters from Maqarin (north Jordan) was responsible for leaching and precipitation of anions and trace elements. A similar scenario was reported in north and central Jordan. The calculated structural formula of fluorapatite is Ca_5.02 (P_2.325, Si_0.22, S_0.0833) O₁₂ F_0.975. The apatite structure incorporates S and Si (inherited from the bituminous precursor) that substitute for P in the tetrahedral positions.  相似文献   

An experimental test of Henry's Law in solid metal‐liquid metal systems with implications for iron meteorites     

Nancy L. CHABOT  Andrew J. CAMPBELL  John H. JONES  Munir HUMAYUN  Carl B. AGEE 《Meteoritics & planetary science》2003,38(2):181-196

Abstract— Experimental solid metal‐liquid metal partition coefficients have been used to model the crystallization of magmatic iron meteorites and understand the evolution of asteroid cores. However, the majority of the partitioning experiments have been conducted with trace elements doped at levels that are orders of magnitude higher than measured in iron meteorites. Concern about Henry's Law and the unnatural doping levels have been cited as one reason that two recent iron meteorite studies have dismissed the experimental partition coefficients in their modeling. Using laser ablation ICP‐MS analysis, this study reports experimentally determined solid metal‐liquid metal trace element partition coefficients from runs doped down to the levels occurring in iron meteorites. The analyses for 12 trace elements (As, Co, Cr, Cu, Ga, Ge, Ir, Os, Pd, Pt, Re, and W) show no deviations from Henry's Law, and these results support decades of experimental work in which the partition coefficients were assumed to be independent of trace element concentration. Further, since our experiments are doped with natural levels of trace elements, the partitioning results are directly applicable to iron meteorites and should be used when modeling their crystallization. In contrast, our new Ag data are inconsistent with previous studies, suggesting the high Ag‐content in previous studies may have influenced the measured Ag partitioning behavior.  相似文献   

Storm Surges in the Strait of Georgia Simulated with a Regional Model     

Nancy Soontiens  Susan E. Allen  Doug Latornell  Kate Le Souëf  Idalia Machuca  Jean-Philippe Paquin 《大气与海洋》2016,54(1):1-21

The Strait of Georgia is a large, semi-enclosed body of water between Vancouver Island and the mainland of British Columbia connected to the Pacific Ocean via Juan de Fuca Strait at the south and Johnstone Strait at the north. During the winter months, coastal communities along the Strait of Georgia are at risk of flooding caused by storm surges, a natural hazard that can occur when a strong storm coincides with high tide. This investigation produces storm surge hindcasts using a three-dimensional numerical ocean model for the Strait of Georgia and the surrounding bodies of water (Juan de Fuca Strait, Puget Sound, and Johnstone Strait) collectively known as the Salish Sea. The numerical model employs the Nucleus for European Modelling of the Ocean architecture in a regional configuration. The model is evaluated through comparisons of tidal elevation harmonics and storm surge with observations. Important forcing factors contributing to storm surges are assessed. It is shown that surges entering the domain from the Pacific Ocean make the most significant contribution to surge amplitude within the Strait of Georgia. Comparisons between simulations and high-resolution and low-resolution atmospheric forcing further emphasize that remote forcing is the dominant factor in surge amplitudes in this region. In addition, local wind patterns caused a slight increase in surge amplitude on the mainland side of the Strait of Georgia compared with Vancouver Island coastal areas during a major wind storm on 15 December 2006. Generally, surge amplitudes are found to be greater within the Strait of Georgia than in Juan de Fuca Strait.  相似文献   

Epistemic and ethical trade-offs in decision analytical modelling     

Martin Vezér  Alexander Bakker  Klaus Keller  Nancy Tuana 《Climatic change》2018,147(1-2):1-10

Designing decision analytical models requires making choices that can involve a range of trade-offs and interactions between epistemic and ethical considerations. Such choices include determining the complexity of a model and deciding what types of risk will be assessed. Here, we demonstrate how model design choices can involve trade-offs between the epistemic benefits of representational completeness and simplicity, which interact with ethical considerations about fairness and human life. We illustrate this point by focusing on modeling studies that assess flood risks in New Orleans, Louisiana. Addressing the ethical and epistemic implications of model design choices can help clarify the scope of factors necessary to inform ethically sound and economically efficient decision-making.  相似文献   

Climate change implications for irrigation and groundwater in the Republican River Basin,USA     

Gengxin Ou  Francisco Munoz-Arriola  Daniel R. Uden  Derrel Martin  Craig R. Allen  Nancy Shank 《Climatic change》2018,151(2):303-316

This study investigates the influence of climate change on groundwater availability, and thereby, irrigation across political boundaries within the US High Plains aquifer. A regression model is developed to predict changes in irrigation according to predicted changes in precipitation and temperature from a downscaled dataset of 32 general circulation models (GCMs). Precipitation recharge changes are calculated with precipitation-recharge curves developed for prognostic representations of precipitation across the Nebraska-Colorado-Kansas area and within the Republican River Basin focal landscape. Irrigation-recharge changes are scaled with changes in irrigation. The groundwater responses to climate forcings are then simulated under new pumping and recharge rates using a MODFLOW groundwater flow model. Results show that groundwater pumping and recharge both will increase and that the effects of groundwater pumping will overshadow those from natural fluctuations. Groundwater levels will decline more in areas with irrigation-driven decreasing trends in the baseline. The methodologies and predictions of this study can inform long-term water planning and the design of management strategies that help avoid and resolve water-related conflicts, enabling irrigation sustainability.  相似文献