Phylogeny of the Sepia officinalis species complex in the eastern Atlantic extends the known distribution of Sepia vermiculata across the Benguela upwelling region     

AJE Healey  NJ McKeown  WM Potts  CL de Beer  W Sauer  PW Shaw 《African Journal of Marine Science》2017,39(3):307-313

Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks.  相似文献   

A middle proterozoic volcanic-plutonic cycle in Saudi Arabia     

J. Kemp 《Precambrian Research》1978,6(1):A28

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Sedimentary record of heavy metal pollution in Lake Erie     

J.O Nriagu  A.L.W Kemp  H.K.T Wong  N Harper 《Geochimica et cosmochimica acta》1979,43(2):247-258

Three cores, one kilometer apart, from each of seven locations along Lake Erie were analyzed for heavy metals and dated by ²¹⁰Pb techniques. The sedimentary record of anthropogenic inputs of heavy metals parallels the increasing intensity of cultural activity in the lake basin. On the average, pollution sources annually contribute 0.4 μg of Cd, 12 μg of Cu, 12 μg of Pb and 36 μg of Zn deposited per each cm² of the Eastern Basin sediments: 0.5, 8.8, 11 and 31 μg of Cd, Cu, Pb and Zn, respectively, deposited per cm² of Western Basin sediments and 0.7, 1.4, 2.0 and 5.6 μg of Cd, Cu, Pb and Zn, respectively, deposited per cm² of fine-grained sediments in the Central Basin. These anthropogenic flux rates exceed the pre-colonial data by 80–600%. The mean flux rates for ²¹⁰Pb into the Eastern. Central and Western Basins are 0.45, 0.07 and 0.15dpm cm^?2 yr^?1. respectively. From an inventory of sources and sinks of the metals, it is shown that about 2500 × 10³ kg of Cu. 1900 × 10³ kg of Pb and 6750 × 10³kg of Zn are delivered annually into the lake. The calculated retention in the lake sediments of 45%, 65% and 35% of the total annual inputs of Cu. Pb and Zn, respectively, agrees closely with the accumulation of data derived from sediment analyses. Sewage discharges, direct and indirect, are shown to be an important source of metal in the lake. The mean residence times in the water column are inferred to be 104 days for Cu. 180 days for Pb and 152 days for Zn.  相似文献   

Response of the phoxocephalid amphipod,Rhepoxynius abronius,to a small oil spill in Yaquina Bay,Oregon     

P. F. Kemp  R. C. Swartz  J. O. Lamberson 《Estuaries and Coasts》1986,9(4):340-347

A spill of approximately 284,000 liters of Bunker C and diesel fuel oils occurred at the entrance of Yaquina Bay, Oregon, following the wreck of the freighterBlue Magpie on 19 November 1983. A portion of this oil entered the lower estuary and was deposited on subtidal benthic habitats occupied by the phoxocephalid amphipodRhepoxynius abronius. This species is particularly sensitive to contaminants in sediment and its life history had previously been studied at the same sites affected by the spill. The oil was initially present as small, sand-coated globules at the study site, and persisted in association with detritus and sediment for months. Bioassays withRhepoxynius abronius showed that the oil globules were not acutely toxic unless mixed into the sediment at concentrations of 1.0 parts per thousand or greater. A series of 10-d bioassays before and after the spill showed that sediment collected from oiled subtidal sites did not become acutely toxic to this species. Although the density of theR. abronius population declined by 75% after the spill, similar declines of the same population were observed at this site in fall 1980. Oil-exposedR. abronius from Yaquina Bay were slightly more sensitive to cadmium in sediment than individuals from Whidbey Island, Puget Sound, Washington. Although mean fecundity was greater in 1984 than in 1981, recruitment following the spill was lower than in the 1980–1981 study. Thus, there is limited evidence for a small impact of the oil spill on this sensitive amphipod.  相似文献   

Investigation as legitimacy: the maturing of the big public inquiry     

R. Kemp  T. O&#x;riordan  M. Purdue 《Geoforum》1984,15(3):477-488

All major resource development schemes lie embedded in political prejudices and commitments, in interest group expectations which themselves are influenced by past events, and in the changing atmosphere of public priorities. A proposal to develop a new technology, which, especially if successful, would lead to further investments of a similar nature but which would by necessity restrict the scope for other opportunities in other policy areas, is bound to be controversial. The inevitable demand is for full justification through some kind of reputable open examination whose conduct and outcome are deemed to be fair and legitimate. While the form of that examination will vary from country to country its function remains the same — namely, to mobilise public support for a decision and the policies that envelop it. In the U.K. the public inquiry seeks to serve such a function. Its constitutional role, history, contemporary style and emerging problems of legitimacy are all examined with reference to the Sizewell B Inquiry into Britain's first pressurised water reactor.  相似文献   

Comparison of proxy records of Late Pleistocene climate change from a high‐resolution loess–palaeosol sequence in north‐central China     

Rob A. Kemp  Edward Derbyshire  Xingmin Meng 《第四纪科学杂志》1999,14(1):91-96

A micromorphologically based pedosedimentary reconstruction of a 40‐m loess–palaeosol sequence from the western part of the Chinese Loess Plateau provides a sensitive proxy record of changing processes and associated environmental conditions in this region between ca. 150 000 and 10 000 yr BP. Depth functions of more traditional climate proxies, such as magnetic susceptibility, calcium carbonate content and median grain size, support the broad pattern of environmental changes inferred from the micromorphology, although the bulk properties sometimes lag behind or are out of phase with each other and do not match all the fluctuations in the micromorphological record. The reasons for the disparities are probably complex, although they partly reflect differences in response rates and sensitivities of proxies to different climate parameters, as well as genuine out‐of‐phase changes in strength of monsoonal climate controls. This work illustrates the sensitivity of micromorphology in detecting past environmental changes within rapidly aggrading landscapes, and emphasises the need to understand more fully the local and regional significance of bulk proxies currently used in global correlations with marine‐ and ice‐core records. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Short-range variations in the micromorphology of a palaeosol from Wivenhoe in southeast England     

Rob. A. Kemp  Joanne S. Faulkner 《第四纪科学杂志》1998,13(3):233-243

The pedogenic histories of four adjacent profiles of a polygenetic palaeosol developed on a Middle Pleistocene terrace of the proto-Thames from Wivenhoe in southeast England are reconstructed on the basis of superposition of key micromorphological features. Despite a considerable variation in macromorphology, partly resulting from large-scale periglacial features, three of the profiles have similar micromorphological records in that they retain evidence for two phases of clay illuviation separated by a period of periglacial disruption. This reconstruction, however, seems to be incomplete because the fourth profile contains micromorphological evidence for a further illuviation–disruption cycle. The extent of this variation suggests that soil micromorphology should be used only with care to reconstruct pedogenic or pedosedimentary histories of complex polygenetic palaeosols, or to compare such palaeosols on different surfaces of chronosequences spanning periods of major climatic change. The variable and possibly limited resolution of micromorphology, together with the current uncertainty over the exact environmental signifiance of illuvial clay features, means that inferred pedogenic phases should be correlated with specific climatic stages only with considerable caution. © 1998 John Wiley & Sons, Ltd.  相似文献   

An early-time infrared and optical study of the Type Ia Supernova 1998bu in M96     

M. Hernandez  W. P. S. Meikle  A. Aparicio  C. R. Benn  M. R. Burleigh  A. C. Chrysostomou  A. J. L. Fernandes  T. R. Geballe  P. L. Hammersley  J. Iglesias-Paramo  D. J. James  P. A. James  S. N. Kemp  T. A. Lister  D. Martinez-Delgado  A. Oscoz  D. L. Pollacco  M. Rozas  S. J. Smartt  P. Sorensen  R. A. Swaters  J. H. Telting  W. D. Vacca  N. A. Walton  M. R. Zapatero-Osorio 《Monthly notices of the Royal Astronomical Society》2000,319(1):223-234

We present first-season infrared (IR) and optical photometry and spectroscopy of the Type Ia Supernova 1998bu in M96. We also report optical polarimetry of this event. SN 1998bu is one of the closest type Ia supernovae of modern times, and the distance of its host galaxy is well determined. We find that SN 1998bu is both photometrically and spectroscopically normal. However, the extinction to this event is unusually high, with     We find that SN 1998bu peaked at an intrinsic     Adopting a distance modulus of 30.25 (Tanvir et al.) and using Phillips et al.'s relations for the Hubble constant, we obtain     Combination of our IR photometry with those of Jha et al. provides one of the most complete early-phase IR light curves for a SN Ia published so far. In particular, SN 1998bu is the first normal SN Ia for which good pre- t _{B max} IR coverage has been obtained. It reveals that the J , H and K light curves peak about 5 days earlier than the flux in the B -band curve.  相似文献   

The solar occultation for ice experiment     

Larry L. Gordley  Mark E. Hervig  Chad Fish  James M. Russell  Scott Bailey  James Cook  Scott Hansen  Andrew Shumway  Greg Paxton  Lance Deaver  Tom Marshall  John Burton  Brian Magill  Chris Brown  Earl Thompson  John Kemp 《Journal of Atmospheric and Solar》2009,71(3-4):300-315

The Solar Occultation For Ice Experiment (SOFIE) was launched onboard the Aeronomy of Ice in the Mesosphere (AIM) satellite on 25 April 2007, and began science observations on 14 May 2007. SOFIE conducts solar occultation measurements in 16 spectral bands that are used to retrieve vertical profiles of temperature, O₃, H₂O, CO₂, CH₄, NO, and polar mesospheric cloud (PMC) extinction at wavelengths from 0.330 to 5.006 μm. SOFIE performs 15 sunset measurements at latitudes from 65° to 85°S and 15 sunrise measurements from 65° to 85°N each day. This work describes the SOFIE instrument, measurement approach, and retrieval results for the northern summer of 2007.  相似文献   

Long-Term Trends in Submersed Aquatic Vegetation (SAV) in Chesapeake Bay, USA, Related to Water Quality     

Robert J. Orth  Michael R. Williams  Scott R. Marion  David J. Wilcox  Tim J. B. Carruthers  Kenneth A. Moore  W. Michael Kemp  William C. Dennison  Nancy Rybicki  Peter Bergstrom  Richard A. Batiuk 《Estuaries and Coasts》2010,33(5):1144-1163

Chesapeake Bay supports a diverse assemblage of marine and freshwater species of submersed aquatic vegetation (SAV) whose broad distributions are generally constrained by salinity. An annual aerial SAV monitoring program and a bi-monthly to monthly water quality monitoring program have been conducted throughout Chesapeake Bay since 1984. We performed an analysis of SAV abundance and up to 22 environmental variables potentially influencing SAV growth and abundance (1984–2006). Historically, SAV abundance has changed dramatically in Chesapeake Bay, and since 1984, when SAV abundance was at historic low levels, SAV has exhibited complex changes including long-term (decadal) increases and decreases, as well as some large, single-year changes. Chesapeake Bay SAV was grouped into three broad-scale community-types based on salinity regime, each with their own distinct group of species, and detailed analyses were conducted on these three community-types as well as on seven distinct case-study areas spanning the three salinity regimes. Different trends in SAV abundance were evident in the different salinity regimes. SAV abundance has (a) continually increased in the low-salinity region; (b) increased initially in the medium-salinity region, followed by fluctuating abundances; and (c) increased initially in the high-salinity region, followed by a subsequent decline. In all areas, consistent negative correlations between measures of SAV abundance and nitrogen loads or concentrations suggest that meadows are responsive to changes in inputs of nitrogen. For smaller case-study areas, different trends in SAV abundance were also noted including correlations to water clarity in high-salinity case-study areas, but nitrogen was highly correlated in all areas. Current maximum SAV coverage for almost all areas remain below restoration targets, indicating that SAV abundance and associated ecosystem services are currently limited by continued poor water quality, and specifically high nutrient concentrations, within Chesapeake Bay. The nutrient reductions noted in some tributaries, which were highly correlated to increases in SAV abundance, suggest management activities have already contributed to SAV increases in some areas, but the strong negative correlation throughout the Chesapeake Bay between nitrogen and SAV abundance also suggests that further nutrient reductions will be necessary for SAV to attain or exceed restoration targets throughout the bay.  相似文献