A deep Chandra survey of the Groth Strip – I. The X-ray data     

K. Nandra  E. S. Laird  K. Adelberger  Jonathan P. Gardner  R. F. Mushotzky  J. Rhodes  C. C. Steidel  H. I. Teplitz  K. A. Arnaud 《Monthly notices of the Royal Astronomical Society》2005,356(2):568-586

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Tribute to John Wasson     

Ed Anders  Derek Sears 《Meteoritics & planetary science》1992,27(1):2-2

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Variations in the Rate of Anaerobic Succinate Accumulation within the Central and Marginal Regions of an Euryoxic Bivalve Mantle     

Ed  Greenfield Miles A.  Crenshaw 《Marine Ecology》1981,2(4):353-362

Abstract. Anaerobic metabolism in the central and marginal portions of the mantle of Mercenaria mercenaria was compared. Anaerobic succinate accumulation was more rapid in the central region. This difference may be due to higher phosphoenolpyruvate carboxykinase activity in the central region. Thus, the central region is more specialized for anaerobic metabolism and the marginal region more for net shell growth. The original rate of succinate accumulation in the mantle is similar in isolated mantles and intact clams, suggesting that mantle succinate production does not require translocation of precursors from other tissues. However, in intact clams, the rate of succinate accumulation in the central region of the mantle slows after four hours. The reduced rate is probably caused by reducing the metabolic rate. Succinate accumulation and shell dissolution are slower in freshly collected clams than in clams that had been stored anaerobically. The difference may be due to induction of PEPCK synthesis during storage. Shell derived calcium did not accumulate in the mantle and, therefore did not alter the intracellular calcium concentration in the mantle.  相似文献   

The Ah receptor in marine animals: phylogenetic distribution and relationship to cytochrome P4501A inducibility     

Mark E. Hahn  Alan Poland  Ed Glover  John J. Stegeman 《Marine environmental research》1992,34(1-4)

In mammals, the induction of cytochrome P4501A forms by chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and halogenated biphenyls is under control of a soluble protein known as the Ah (aromatic hydrocarbon) receptor. Little is known about the presence and properties of the Ah receptor in other vertebrate and invertebrate species. In these studies, we sought evidence for an Ah receptor in the liver or liver-equivalent of 20 species of marine and freshwater animals, using the photoaffinity ligand 2-azido-3-[¹²⁵I] iodo-7,8-dibromodibenzo-p-dioxin (N₃[¹²⁵I]Br₂DD). Specific labeling of cytosolic proteins by N₃[¹²⁵I]Br₂DD was observed in seven species of teleost and elasmobranch fish, in PLHC-I fish hepatoma cells, and in beluga whales. No specifically labeled proteins were found in cytosol from two species of agnathan fish nor in any of nine invertebrate species representing eight classes of four phyla. The presence or absence of specifically labeled polypeptides corresponds with the inducibility of cytochrome P4501A and sensitivity to the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related planar halogenated aromatic hydrocarbons in many of these groups. Thus, Ah receptor function may have arisen early invertebrate evolution and has been conserved from elasmobranch and teleost fish to mammals.  相似文献   

The effects of sewage discharge on water quality and phytoplankton of Hawai'ian coastal waters     

Parnell PE 《Marine environmental research》2003,55(4):293-311

The effects of sewage discharge on algal populations and the quality of Hawai'ian coastal waters were investigated. Two outfalls were studied. One discharges primary treated sewage and the other discharges secondary treated sewage but are otherwise similar. This enabled comparisons of the effects of these different levels of treatment on the water quality and algal productivity of receiving waters. Plumes were followed and repeatedly sampled in a time-series manner. Rhodamine dye was used as a conservative tracer to compare the dilution behavior of the plume constituents MRP, NO(3)+NO(2), NH(4), Silicate, TDP, TDN, total bacteria, PC, and PN. Rates of initial dilution ranged from two to almost three orders of magnitude, and were in reasonable agreement with engineering model predictions. Dilution of plume constituents approximated that of Rhodamine until background concentrations were reached, typically within 10 min of discharge. Chl a concentrations did not increase through time in the primary sewage plume but did increase up to 30% in the secondary sewage plume. However, rates of far-field dilution were so rapid that the increase could not have been due to algal growth. The increase was attributed to the plume mixing with a water mass whose relative chl a concentrations were greater. Rates of secondary dilution ranged from 2 to 3 orders of magnitude resulting in total dilutions of 10(5)-10(6) within 3 h of discharge. These rates of secondary dilution were much greater than model predictions. From a nutrient standpoint, secondary treatment exhibited no advantages over primary treatment because dilutions were so rapid.  相似文献   

Bury, Burn or Both: A Two-for-One Deal on Biomass Carbon and Energy     

David W. Keith  James S. Rhodes 《Climatic change》2002,54(3):375-377

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Beyond world cities: Central America in a global space of flows   总被引：1，自引：0，他引：1  

Ed Brown  Peter J. Taylor  & Gilda Catalano 《Area》2002,34(2):139-148

Central America is a region without a world city. Traditionally, the region's national projects have been based upon openness to the world economy: how do the region's contemporary transnational projects connect to the world economy under the new conditions of openness that is contemporary globalization? Focusing upon advanced producer services, three connections into the world city network are identified: global service firms operating directly in Central American cities, local service firms operating indirectly through extra-regional world cities and global service firms operating through Latin American regional offices. Miami is confirmed as the primary world city through which Central America connects into the world economy  相似文献   

Precambrian–Cambrian boundary interval deposition and the marginal platform of the Avalon microcontinent     

Ed Landing   《Journal of Geodynamics》2004,37(3-5):411

Thick terminal Proterozoic–lowest Cambrian successions allow reference of the Saint John, New Brunswick, and MacCodrum Brook, southern Cape Breton Island, areas to the marginal platform of the Avalon microcontinent. Marginal-platform siliciclastic-dominated sequences form a cover on Late Precambrian arc successions from southern New Brunswick to North Wales. Their deposition in fault-bounded basins began with the origin of the Avalon microcontinent and development of a persistent transtensional regime in the latest Precambrian. The terminal Proterozoic–lowest Cambrian on the Avalonian marginal platform consists of three successive lithofacies associations: lower subaerial rift to marginal-marine facies; overlying cool-water, wave-influenced, marine platform sandstones and shales; and higher macrotidal quartz arenites (=Avalonian depositional sequences 1–2). Only the Lower Cambrian macrotidal quartz arenites onlap southeast, where they form the oldest Cambrian unit on the inner platform. These major lithofacies are the Rencontre, Chapel Island, and Random formations, respectively, in Avalonian North America. Southwest thinning of the Rencontre–Chapel Island–Random interval in southern New Brunswick reflects slower subsidence of a fault-bounded area in the city of Saint John. The depositional sequence 1–2 unconformity, which falls in the sub-trilobitic Lower Cambrian Watsonella crosbyi Zone of the Chapel Island Formation, persists for 650 km along the marginal platform from southeastern Newfoundland to southern New Brunswick and, potentially, appears in Cape Breton Island. Latest Precambrian-earliest Cambrian epeirogenic and depositional history was very uniform along the marginal platform, and a unified lithostratigraphic nomenclature is appropriate.  相似文献   

The Ninole Basalt — Implications for the structural evolution of Mauna Loa volcano,Hawaii     

Peter W Lipman  J M Rhodes  G Brent Dalrymple 《Bulletin of Volcanology》1990,53(1):1-19

Lava flows of the Ninole Basalt, the oldest rocks exposed on the south side of the island of Hawaii, provide age and compositional constraints on the evolution of Mauna Loa volcano and the southeastward age progression of Hawaiian volcanism. Although the tholeiitic Ninole Basalt differs from historic lavas of Mauna Loa volcano in most major-element contents (e.g., variably lower K, Na, Si; higher Al, Fe, Ti, Ca), REE and other relatively immobile minor elements are similar to historic and prehistoric Mauna Loa lavas, and the present major-element differences are mainly due to incipient weathering in the tropical environment. New K-Ar whole-rock ages, from relatively fresh roadcut samples, suggest that the age of the Ninole Basalt is approximately 0.1–0.2 Ma, although resolution is poor because of low contents of K and radiogenic Ar. Originally considered the remnants of a separate volcano, the Ninole Hills are here interpreted as faulted remnants of the old south flank of Mauna Loa. Deep canyons in the Ninole Hills, eroded after massive landslide failure of flanks of the southwest rift zone, have been preserved from burial by younger lava due to westward migration of the rift zone. Landslide-induced depressurization of the southwest rift zone may also have induced phreatomagmatic eruptions that could have deposited widespread Basaltic ash that overlies the Ninole Basalt. Subaerial presence of the Ninole Basalt documents that the southern part of Hawaii Island had grown to much of its present size above sea level by 0.1–0.2 Ma, and places significant limits on subsequent enlargement of the south flank of Mauna Loa.  相似文献   

The Ninole Basalt — Implications for the structural evolution of Mauna Loa volcano, Hawaii     

Peter W Lipman  J M Rhodes  G Brent Dalrymple 《Bulletin of Volcanology》1991,53(1):1-19

Lava flows of the Ninole Basalt, the oldest rocks exposed on the south side of the island of Hawaii, provide age and compositional constraints on the evolution of Mauna Loa volcano and the southeastward age progression of Hawaiian volcanism. Although the tholeiitic Ninole Basalt differs from historic lavas of Mauna Loa volcano in most major-element contents (e.g., variably lower K, Na, Si; higher Al, Fe, Ti, Ca), REE and other relatively immobile minor elements are similar to historic and prehistoric Mauna Loa lavas, and the present major-element differences are mainly due to incipient weathering in the tropical environment. New K-Ar whole-rock ages, from relatively fresh roadcut samples, suggest that the age of the Ninole Basalt is approximately 0.1–0.2 Ma, although resolution is poor because of low contents of K and radiogenic Ar. Originally considered the remnants of a separate volcano, the Ninole Hills are here interpreted as faulted remnants of the old south flank of Mauna Loa. Deep canyons in the Ninole Hills, eroded after massive landslide failure of flanks of the southwest rift zone, have been preserved from burial by younger lava due to westward migration of the rift zone. Landslide-induced depressurization of the southwest rift zone may also have induced phreatomagmatic eruptions that could have deposited widespread Basaltic ash that overlies the Ninole Basalt. Subaerial presence of the Ninole Basalt documents that the southern part of Hawaii Island had grown to much of its present size above sea level by 0.1–0.2 Ma, and places significant limits on subsequent enlargement of the south flank of Mauna Loa.  相似文献