Cloning and analysis of the CYP1A promoter from the atlantic killifish (Fundulus heteroclitus)     

Wade H. Powell  Hilary G. Morrison  E. Jennifer Weil  Sibel I. Karchner  Mitchell L. Sogin  John J. Stegeman  Mark E. Hahn 《Marine environmental research》2004,58(2-5):119

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Spectral characteristics of the Gawler Range Volcanics in drill core Myall Creek RC1     

G. Gordon  S. McAvaney  C. Wade 《Australian Journal of Earth Sciences》2016,63(8):973-986

Traditional core-logging methods in conjunction with spectral scanning techniques have been used to log volcanic successions of the lower Gawler Range Volcanics. The open-file drill core Myall Creek RC 1 was re-logged and scanned using HyLogger? core scanning technologies as a part of the Geological Survey of South Australia's Southern Gawler Rangers mapping program and the Mineral System Drilling Program. Myall Creek RC 1 is one of the key stratigraphic drill cores for the region, owing to the intersection of a large section of the Gawler Range Volcanics. Spectral characterisation of the Eucarro Rhyolite revealed differential weathering of plagioclase phenocrysts, while high-resolution imagery and spectral results were used to log new basaltic flows and small flow features in the Roopena Basalt. The composition and distribution of feldspars in the unnamed lower Gawler Range Volcanic units were used to aid traditional logging of visually similar lithologies. A spectral scalar, the felsic–mafic index, was used to identify unusual features in the unnamed sequence and was found to identify iron oxides as either fracture coatings or finely disseminated in the matrix of the sample. Iron oxides were also used to identify features within lithological units, which were difficult to discern visually, especially the layers in the deepest layered ignimbrite at the end of the drill core.  相似文献   

Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, southern coastal Tanzania   总被引：2，自引：0，他引：2  

Christopher J. Nicholas  Paul N. Pearson  Paul R. Bown  Tom Dunkley Jones  Brian T. Huber  Amina Karega  Jackie A. Lees  Ian K. McMillan  Aoife O&#x;Halloran  Joyce M. Singano  Bridget S. Wade 《Journal of African Earth Sciences》2006,45(4-5):431-466

The geology of southern coastal Tanzania has remained poorly understood since the first comments on its stratigraphy were made over 100 years ago. However, new field surveys combined with shallow drilling along the coast between Kilwa and Lindi are beginning to resolve the depositional history and structural evolution of this region over the past 85 Ma. Here we present the first attempt to synthesize the results of these studies to provide a coherent sedimentological, litho- and sequence stratigraphic framework, including new geological maps, for the Upper Cretaceous and Paleogene of the coastal zone.Santonian to Oligocene sediments crop out along a broad coastal belt south of the Rufiji River from the Kilwa peninsula to Lindi Creek in southern Tanzania. During 55 Ma, over 1 km of a broadly homogeneous, mid to outer shelf clay-dominated succession was deposited across the passive margin, which we define here as the Kilwa Group. This lies disconformably across the shelf on Albian marls and is itself unconformably overlain by shallow water Miocene clays and more recent limestones, sands and gravels. Four formations can be identified within the Kilwa Group on the basis of characteristic secondary lithologies and facies, described here for the first time; the Nangurukuru, Kivinje, Masoko and Pande Formations. These formations include conformable stratigraphic intervals through both the Paleocene–Eocene and Eocene–Oligocene boundaries. Within the Kilwa Group, 12 sequence stratigraphic cycles can be identified at present, demonstrating relatively uniform and continual subsidence across the margin from Santonian to Early Oligocene time. A further major bounding surface is present between the Upper Cretaceous and Paleogene, but this may become partly conformable in the Lindi area. Although the principal lithology in all formations is clay or claystone, there are more permeable intervals containing pervasive coarser siliciclastic sediments and these have yielded traces of crude oil which is likely to have migrated from lower in the succession. The Kilwa Group thus also provides important new evidence for petroleum play development in the southern coastal zone.  相似文献   

Assessment of persistent organochlorine residues in sediments of Hadramout coastal area, Gulf of Aden, Yemen   总被引：1，自引：0，他引：1  

Mostafa AR  Wade TL  Sweet ST  Al-Alimi AK  Barakat AO 《Marine pollution bulletin》2007,54(7):1053-1058

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Use of chemical tracers in assessing the diet and foraging regions of eastern North Pacific killer whales     

Krahn MM  Herman DP  Matkin CO  Durban JW  Barrett-Lennard L  Burrows DG  Dahlheim ME  Black N  LeDuc RG  Wade PR 《Marine environmental research》2007,63(2):91-114

Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers-stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles-were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n=84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.  相似文献   

On the periodic solutions of a rigid dumbbell satellite in a circular orbit     

Juan L. G. Guirao  Juan A. Vera  Bruce A. Wade 《Astrophysics and Space Science》2013,346(2):437-442

The aim of the present paper is to provide sufficient conditions for the existence of periodic solutions of the perturbed attitude dynamics of a rigid dumbbell satellite in a circular orbit.  相似文献   

Towards the estimation root-zone soil moisture via the simultaneous assimilation of thermal and microwave soil moisture retrievals     

Fuqin Li  Wade T. Crow  William P. Kustas 《Advances in water resources》2010

The upcoming deployment of satellite-based microwave sensors designed specifically to retrieve surface soil moisture represents an important milestone in efforts to develop hydrologic applications for remote sensing observations. However, typical measurement depths of microwave-based soil moisture retrievals are generally considered too shallow (top 2–5 cm of the soil column) for many important water cycle and agricultural applications. Recent work has demonstrated that thermal remote sensing estimates of surface radiometric temperature provide a complementary source of land surface information that can be used to define a robust proxy for root-zone (top 1 m of the soil column) soil moisture availability. In this analysis, we examine the potential benefits of simultaneously assimilating both microwave-based surface soil moisture retrievals and thermal infrared-based root-zone soil moisture estimates into a soil water balance model using a series of synthetic twin data assimilation experiments conducted at the USDA Optimizing Production Inputs for Economic and Environmental Enhancements (OPE³) site. Results from these experiments illustrate that, relative to a baseline case of assimilating only surface soil moisture retrievals, the assimilation of both root- and surface-zone soil moisture estimates reduces the root-mean-square difference between estimated and true root-zone soil moisture by 50% to 35% (assuming instantaneous root-zone soil moisture retrievals are obtained at an accuracy of between 0.020 and 0.030 m³ m⁻³). Most significantly, improvements in root-zone soil moisture accuracy are seen even for cases in which root-zone soil moisture retrievals are assumed to be relatively inaccurate (i.e. retrievals errors of up to 0.070 m³ m⁻³) or limited to only very sparse sampling (i.e. one instantaneous measurement every eight days). Preliminary real data results demonstrate a clear increase in the R² correlation coefficient with ground-based root-zone observations (from 0.51 to 0.73) upon assimilation of actual surface soil moisture and tower-based thermal infrared temperature observations made at the OPE³ study site.  相似文献   

Assessment of persistent organochlorine pollutants in sediments from Lake Manzala, Egypt   总被引：2，自引：0，他引：2  

Barakat AO  Mostafa A  Wade TL  Sweet ST  El Sayed NB 《Marine pollution bulletin》2012,64(8):1713-1720

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in surface and core sediment samples collected from Manzala Lake, the largest of the Egyptian coastal lakes. Total concentrations of OCPs and ∑7 PCBs (ICES) in sediments ranged from 0.63 to 31.31 ng/g and 0.26 to 31.27 ng/g, respectively. Geographical distribution indicates that levels of contaminants were significantly higher in areas which are mainly influenced by municipal discharge, indicating significant sources of these compounds in urbanised areas. The composition of DDT and its metabolites suggest old input of DDT. The levels of contaminants in Manzala Lake were similar or lower than those observed in comparable areas worldwide. The profiles of ∑OCPs and ∑PCBs in a core from a site heavily impacted by sewage discharge have highest concentrations in the surface core section indicating recent inputs. Assessment of ecotoxicological risk indicated that sediments in two sites were likely to pose potential biological adverse impact.  相似文献   

Automated cleaning and uncertainty attribution of archival bathymetry based on a priori knowledge   总被引：1，自引：0，他引：1  

Rodney Wade Ladner  Paul Elmore  A. Louise Perkins  Brian Bourgeois  Will Avera 《Marine Geophysical Researches》2017,38(3):291-301

Hydrographic offices hold large valuable historic bathymetric data sets, many of which were collected using older generation survey systems that contain little or no metadata and/or uncertainty estimates. These bathymetric data sets generally contain large outlier (errant) data points to clean, yet standard practice does not include rigorous automated procedures for systematic cleaning of these historical data sets and their subsequent conversion into reusable data formats. In this paper, we propose an automated method for this task. We utilize statistically diverse threshold tests, including a robust least trimmed squared method, to clean the data. We use LOESS weighted regression residuals together with a Student-t distribution to attribute uncertainty for each retained sounding; the resulting uncertainty values compare favorably with native estimates of uncertainty from co-located data sets which we use to estimate a point-wise goodness-of-fit measure. Storing a cleansed validated data set augmented with uncertainty in a re-usable format provides the details of this analysis for subsequent users. Our test results indicate that the method significantly improves the quality of the data set while concurrently providing confidence interval estimates and point-wise goodness-of-fit estimates as referenced to current hydrographic practices.  相似文献   

Stream chloride concentrations as a function of land use: a comparison of an agricultural watershed to an urban agricultural watershed     

Samanta Manon Lax  Eric Wade Peterson  Stephen J. Van der Hoven 《Environmental Earth Sciences》2017,76(20):708

The concentration of chloride (Cl^?) in streams in northern regions has increased as a result of applications of deicers. This study focused on quantifying the relationship between land use and stream Cl^? concentrations. The study area comprises two adjacent watersheds in central Illinois, with similar geology and climate but different land uses (agricultural and urban). GIS analysis delineated watershed land use and calculated road surface areas. Stream water samples were collected and analyzed for anionic composition. During the winter months, streams dominated with urban land use experienced a 20-fold increase in Cl^? concentrations (range between 36 and 1350 mg L^?1); Cl^? concentrations in agricultural dominated streams also increased, but the increase was smaller (3X) and concentrations remained low (between 11 and 58 mg L^?1). As road salts are not the sole source of Cl^? in a stream, Cl^? and bromide (Br^?) mass ratios (Cl/Br) and Cl^? and sodium (Na) molar ratios ([Cl]/[Na]) were used to identify potential sources of Cl^?. The ratios indicate urbanized watersheds were impacted by road salts; agricultural watersheds ratios indicate other anthropogenic sources. A nonlinear relationship between urban land use and stream Cl^? concentrations indicates urban land use as low as 23% results in elevated Cl^? concentrations (greater than 150 mg L^?1) in stream waters.  相似文献