Taxonomic description of a new marine ciliate,Euplotes qingdaoensis n. sp. (Ciliophora: Euplotida)     

陈相瑞  马洪钢 《中国海洋湖沼学报》2014,32(2):426-432

The characteristics and infraciliature of a new euplotid ciliate,Euplotes qingdaoensis n.sp.,discovered from the coastal waters of Jiaozhou Bay,northern China,were studied using live observation and silver impregnation.The new marine species is characterized by a slightly fl attened body(90–110 μm×70–80 μm,in vivo),an adoral zone of 26–29 membranelles,10 strong frontoventral and fi ve transverse cirri,two caudal cirri,a single left marginal cirrus,seven dorsal kineties,a middle kinety with about 15 pairs of basal bodies,a silverline system of the double-eurystomus type,and a C-shaped macronucleus.  相似文献   

Dokhan volcanics of Gabal Monqul area,North Eastern Desert,Egypt: geochemistry and petrogenesis     

Adel A. A. Abdel Wahed  Khaled G. Ali  Magdy M. A. Khalil  Ahmed E. Abdel Gawad 《Arabian Journal of Geosciences》2012,5(1):29-44

The Dokhan volcanics are represented by a thick stratified lava flows succession of basalt, andesite, imperial porphyry, dacite, rhyodacite, rhyolite, ignimbrites, and tuffs. These lavas are interbanded with their pyroclastics in some places including banded ash flow tuffs, lithic tuffs, crystal lapilli tuffs, and agglomerates. They are typical calc–alkaline and developed within volcanic arc environment. All rocks show moderate enrichment of most large ion lithophile elements relative to high field strength elements (HFSE). The incompatible trace elements increase from basalt through andesite to rhyolite. The felsic volcanics are characterized by moderate total rare earth elements (REE) contents (162 to 392 ppm), less fractionated patterns {(Ce/Yb)_N = (1.24 to 10.93)}, and large negative Eu anomaly {(Eu/Eu*) = (0.15 to 0.92)}. The mafic volcanics have the lowest REE contents (61 to 192 ppm) and are relatively steep {(Ce/Yb)_N = (3.2 to 8.5)}, with no negative Eu anomalies {(Eu/Eu*) = (0.88 to 1)}. The rhyolite displays larger negative Eu anomaly (Eu/Eu* = 0.28) than those of other varieties, indicating that the plagioclase was an early major fractionating phase. The mineralogical and chemical variations within volcanics are consistent with their evolution by fractional crystallization of plagioclase and clinopyroxene.  相似文献   

Miocene to recent alkaline volcanism between Al Haruj and Waw an Namous (southern Libya)   总被引：1，自引：0，他引：1  

Jacques-Marie Bardintzeff  Catherine Deniel  Hervé Guillou  Bernard Platevoet  Philippe Télouk  Khaled M. Oun 《International Journal of Earth Sciences》2012,101(4):1047-1063

Unspiked K–Ar ages, petrological, geochemical and isotopic data are reported on samples from southern Libya (Wan an Namous—Al Haruj area). The Wan an Namous intracaldera cone dated at 0.2?Ma consists of unusually undersaturated foidite, representing the most extreme compositions among Libyan and Tibestian lavas. A basanitic and a basaltic lava flow located north-west of Wan an Namous, and probably belonging to the Al Haruj volcanic field, were dated at 5.1?Ma and 8.1?Ma. These data extend the range of ages previously reported for Al Haruj lavas. REE and multi-element patterns are typical of alkaline intraplate magmas. Sr ratios range from 0.70314 to 0.70812, whereas Nd ratios are very homogeneous (0.51290–0.51293). Pb ratios (19.231?<?²⁰⁶Pb/²⁰⁴Pb?<?19.547, 15.607?<?²⁰⁷Pb/²⁰⁴Pb?<?15.641 and 38.859?<?²⁰⁸Pb/²⁰⁴Pb?<?39.242) are typical of HIMU-FOZO compositions. Such isotope characteristics are very similar to those available on two Gharyan (northern Libya) lavas and largely overlap those of Hoggar and Cameroon Line alkaline rocks. These lavas were produced by low and variable degrees of partial melting of a garnet- and amphibole-bearing mantle source, constraining the depth of melting between 80 and 150?km. Crustal contamination was also probably involved for the oldest sample. Mineral compositions of a dunite–harzburgite xenolith clearly indicate that the lithospheric mantle was affected by partial melting and metasomatic processes by magmatic liquids, probably associated with the genesis of Cenozoic lavas. Lithospheric delamination and asthenospheric upwelling, due to the reactivation of lithospheric megastructures induced by the Africa-Europe convergence, could represent a model for the genesis of Libyan lavas, as in Hoggar.  相似文献   

Petrography, chemistry and genesis of phosphorite concretions in the Eocene Umm Rijam Chert limestone Formation, Ma'an area, south Jordan   总被引：1，自引：0，他引：1  

Khalid Tarawneh  Khaled Moumani 《Journal of Asian Earth Sciences》2006,26(6):627-635

Phosphorite concretions are recorded for the first time within the lower part of the Umm Rijam Chert Limestone Formation (Eocene) in the Ma'an area, southern Jordan. The phosphorite concretions are typically hosted and encountered as individual layer in moderately lithified sediments of marl, chalk and chalky marl. The phosphorite concretions are present in thin layer (10–30 cm thick). They are localized on a hardground surface that formed as a result of cementation of soft ground by bioclastic materials. Light grey and brownish to black colors are encountered with isometric, ellipsoid, elongated, subangular to subrounded phosphorite concretions (up to 6 cm in length). Most of the phosphorite concretions preserve bioturbation structures; they also include fecal pellets of various sizes. The main biogenic components are fragments of macrofossils (bivalves) and microfossils (planktonic foraminifera) in different proportions. Petrographic examinations reveal that the phosphorite concretions are composed of cryptocrystalline apatite that characteristically appears in cross-polarized light almost as isotropic phosphate and minor anisotropic phosphate. Apatite and calcite are the main mineral constituents of the phosphorite concretions identified by XRD. The apatite is identified as francolite (carbonate-flour-apatite). Chemical analyses of the phosphorite concretions using X-ray florescence indicate that the P₂O₅ content ranges from 18.8 to 31.19%, whereas SEM–EDS analyses indicate that the phosphorus proportion is around 14% by volume. It could be argued that the phosphorite concretions were transported after being reworked, or were derived from carbonate and chalk pebbles that were later phosphatized and subjected to erosion, forming residual lag deposit along the hardground surface.  相似文献   

Application of GPS in Traffic Management Systems     

Ardeshir Faghri  Khaled Hamad 《GPS Solutions》2002,5(3):52-60

Integrated Traffic Management Systems (ITMS) need reliable, accurate, and real-time data. Travel time, speed, and delay are three of the most important factors used in ITMS for monitoring, quantifying, and controlling congestion. GPS has recently become available for civil applications. Because it provides real-time spatial and time measurements, it has an increasing use in conducting different transportation studies. This article presents the application of GPS in collecting travel time, speed, and delay information of 64 major roads in the state of Delaware. A comparative statistical analysis was performed on data collected by GPS, with data collected simultaneously by the conventional method. The GPS data proved to be at least as accurate as the data collected by the conventional method, and it was 50% more efficient in terms of manpower. Moreover, the sample-size requirement was determined to maintain 95% confidence level throughout the controlled test. Benefiting from the Geographic Information System's dynamic segmentation tool, our travel time, delay, and speed information were integrated with other relevant traffic data. This was presented graphically on the Internet for public use. Statistical trend analysis for the data collected in 1997, 1998, 1999, and 2000 are also presented and applications on the overall ITMS are discussed. ? 2002 Wiley Periodicals, Inc.  相似文献   

Active faulting and natural hazards in Armenia, eastern Turkey and northwestern Iran   总被引：1，自引：0，他引：1  

Arkady S. Karakhanian  Vladimir G. Trifonov  Herve Philip  Ara Avagyan  Khaled Hessami  Farshad Jamali  M. Salih Bayraktutan  H. Bagdassarian  S. Arakelian  V. Davtian  A. Adilkhanyan 《Tectonophysics》2004,380(3-4):189-219

Active fault zones of Armenia, SE Turkey and NW Iran present a diverse set of interrelated natural hazards. Three regional case studies in this cross-border zone are examined to show how earthquakes interact with other hazards to increase the risk of natural disaster. In northern Armenia, a combination of several natural and man-made phenomena (earthquakes, landslides and unstable dams with toxic wastes) along the Pambak-Sevan-Sunik fault (PSSF) zone lowers from 0.4 to 0.2–0.3g the maximum permissible level (MPL) of seismic hazard that may induce disastrous destruction and loss of life in the adjacent Vanadzor depression.

In the Ararat depression, a large active fault-bounded pull-apart basin at the junction of borders of Armenia, Turkey, Iran and Azerbaijan, an earthquake in 1840 was accompanied by an eruption of Ararat Volcano, lahars, landslides, floods, soil subsidence and liquefaction. The case study demonstrates that natural hazards that are secondary with respect to earthquakes may considerably increase the damage and the casualties and increase the risk associated with the seismic impact.

The North Tabriz–Gailatu fault system poses a high seismic hazard to the border areas of NW Iran, eastern Turkey, Nakhichevan (Azerbaijan) and southern Armenia. Right-lateral strike–slip motions along the North Tabriz fault have given rise to strong earthquakes, which threaten the city of Tabriz with its population of 1.2 million.

The examples illustrate how the concentration of natural hazards in active fault zones increases the risk associated with strong earthquakes in Armenia, eastern Turkey and NW Iran. This generally occurs across the junctions of international borders. Hence, the transboundary character of active faults requires transboundary cooperation in the study and mitigation of the natural risk.  相似文献   

Characterization of complex fluvial systems using remote sensing of spatial and temporal water level variations in the Amazon,Congo, and Brahmaputra Rivers   总被引：1，自引：0，他引：1  

Hahn Chul Jung  James Hamski  Michael Durand  Doug Alsdorf  Faisal Hossain  Hyongki Lee  A. K. M. Azad Hossain  Khaled Hasan  Abu Saleh Khan  A.K.M. Zeaul Hoque 《地球表面变化过程与地形》2010,35(3):294-304

The Surface Water and Ocean Topography (SWOT) satellite mission will provide global, space‐based estimates of water elevation, its temporal change, and its spatial slope in fluvial environments, as well as across lakes, reservoirs, wetlands, and floodplains. This paper illustrates the utility of existing remote sensing measurements of water temporal changes and spatial slope to characterize two complex fluvial environments. First, repeat‐pass interferometric SAR measurements from the Japanese Earth Resources Satellite are used to compare and contrast floodplain processes in the Amazon and Congo River basins. Measurements of temporal water level changes over the two areas reveal clearly different hydraulic processes at work. The Amazon is highly interconnected by floodplain channels, resulting in complex flow patterns. In contrast, the Congo does not show similar floodplain channels and the flow patterns are not well defined and have diffuse boundaries. During inundation, the Amazon floodplain often shows sharp hydraulic changes across floodplain channels. The Congo, however, does not show similar sharp changes during either infilling or evacuation. Second, Shuttle Radar Topography Mission measurements of water elevation are used to derive water slope over the braided Brahmaputra river system. In combination with in situ bathymetry measurements, water elevation and slope allow one to calculate discharge estimates within 2.3% accuracy. These two studies illustrate the utility of satellite‐based measurements of water elevation for characterizing complex fluvial environments, and highlight the potential of SWOT measurements for fluvial hydrology. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Molecular phylogeny of oligotrich genera Omegastrombidium and Novistrombidium (Protozoa, Ciliophora) for the systematical relationships within Family Strombidiidae     

张倩倩  伊珍珍  徐大鹏  龚骏  宋微波 《中国海洋湖沼学报》2010,28(4):769-777

The phylogeny of the oligotrich ciliates is currently a hot debate despite the availability of both morphological and molecular data. In the present paper, further small subunit rRNA (SS rRNA) genes were analyzed from the Genera Omegastrombidium and Novistrombidium, as well as from Strombidium, and combined with three new SS rRNA sequences from Strombidium basimorphum, S. sulcatum population QD-1, and Novistrombidium testaceum population GD. The phylogenetic positions of these organisms were inferred using Bayesian inference, Maximum Likelihood, and Maximum Parsimony methods. The main results are: (1) the SS rRNA gene sequence analyses match the recent findings about the molecular evolution of oligotrichs, indicating that the family Strombidiidae is paraphyletic; (2) the Genus Omegastrombidium is separated from the Genus Strombidium, as shown in recent cladistic analyses; (3) morphospecies in Genus Novistrombidium, based on similarity of somatic ciliature, are separated from each other in all topological trees, indicating that this genus could be a paraphyletic group; (4) the molecular data indicate a possibility of paraphyly for the genus Strombidium; and (5) the similarities of the SS rRNA gene of specimens identified as S. sulcatum and S. inclinatum are 99.8%–100%. However, present knowledge on the oligotrichs sensu stricto is still insufficient and further studies based on both molecular and other technologies are required.  相似文献   

Temporal population dynamics of dinoflagellate Prorocentrum minimum in a semi-enclosed mariculture pond and its relationship to environmental factors and protozoan grazers     

许恒龙  MIN Gi-Sik  CHOI Joong-Ki  朱明壮  姜勇  AL-RASHEID Khaled A.S. 《中国海洋湖沼学报》2010,(1)

The ecological processes and interrelationships between protists,either autotrophic or heterotrophic,and environmental factors in mariculture ponds are largely unknown.This study investigated the temporal dynamics of potentially harmful dinoflagellate,Prorocentrum minimum (Pavillard) Schiller,and its relationship to physico-chemical factors and protozoan grazers over a complete cycle in a semi-enclosed shrimp-farming pond near Qingdao,Northern China.P.minimum occurred frequently in low numbers from June to ...  相似文献   

Genetic and morphological divergence in the purple sea urchin Paracentrotus lividus (Echinodermata, Echinoidea) across the African Mediterranean coast     

Temim Deli  Mohamed Hbib Ben Atti  Rym Zitari-Chatti  Khaled Sai  Noureddine Chatti 《海洋学报(英文版)》2017,36(12):52-66

The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA (canonical discriminant analyses), pairwise NPMANOVA (non parametric multivariate analysis of variance) comparisons and MDS (multidimensional scaling) plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM (analysis of similarities) and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER (similarity percentages) routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mtDNA COI (cytochrome oxidase I) gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin, as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA (analysis of molecular variance) analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range.  相似文献