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Upper Part (upper + part)
Selected AbstractsMAPPING AND CLASSIFYING FLOW UNITS IN THE UPPER PART OF THE MID-CRETACEOUS SARVAK FORMATION (WESTERN DEZFUL EMBAYMENT, SW IRAN) BASED ON A DETEMINATION OF RESERVOIR ROCK TYPESJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2007B. Beiranvand The mid-Cretaceous Sarvak Formation, the second-most important reservoir unit in Iran, is composed mainly of grain-supported carbonates. For the purposes of this study, flow units in the upper part of the formation were identified, mapped and classified as part of an integrated reservoir characterization study at a giant oilfield in SW Iran. Pore types and geometries, pore-scale diagenetic history and core-scale depositional attributes were logged using conventional petrographic and lithological methods. The resulting data were combined with core descriptions, mercury-injection capillary pressure data, and wireline log and geophysical data to identify five reservoir rock types: (i) highly oil-stained, grain-supported carbonates, including patch reef and barrier complex deposits with high porosities and permeabilities; (ii) leeward and seaward shoal deposits including grain-supported packstones and skeletal wackestones with high porosities and permeabilities; (iii) dominantly mud-supported lagoonal and open-marine facies with fair porosity and permeability; (iv) grain-supported but highly cemented facies which had poor reservoir characteristics; and (v) calcareous shales and shaly limestones with no reservoir quality. Based on the reservoir rock types, eight flow units were recognised. Subsequently, four reservoir zones were defined based on these flow units at a field scale. This study has contributed to our understanding of flow units in this complex carbonate reservoir, and has improved our ability to characterize and model the architecture of the reservoir from pore to core to field scale. [source] INTRADUCTAL ULTRASONOGRAPHY OF THE GALLBLADDER IN APPLICATION OF THE ENDOSCOPIC NASO-GALLBLADDER DRAINAGEDIGESTIVE ENDOSCOPY, Issue 1 2007Daisuke Masuda Background:, Although endoscopic naso-gallbladder drainage (ENGBD) for gallbladder disease is useful, the procedure is difficult and investigations involving many cases are lacking. Furthermore, reports on transpapillary intraductal ultrasonography (IDUS) of the gallbladder using a miniature probe are rare. Methods:, A total of 150 patients (119 suspected of having gallbladder carcinoma, 24 with acute cholecystitis (AC), and seven with Mirizzi's syndrome (MS)) were the subject. (i) ENGBD: We attempted to put ENGBD tube into the GB. (ii) IDUS of the gallbladder: Using the previous ENGBD tube, we attempted to insert the miniature probe into the gallbladder and perform transpapillary IDUS of the gallbladder. In five patients, we attempted three-dimensional intraductal ultrasonography (3D-IDUS). Results:, (i) ENGBD: Overall success rate was 74.7% (112/150); the rate for the patients suspected of having gallbladder carcinoma was 75.6% (90/119), and was 71.0% (22/31) for the AC and MS patients. Inflammation and jaundice improved in 20/22 successful patients with AC and MS. Success rate was higher when cystic duct branching was from the lower and middle parts of the common bile duct than from the upper part, and was higher when branching was upwards than downwards. (ii) IDUS of the gallbladder: Success rate for miniature probe insertion into the gallbladder was 96.4% (54/56). Lesions could be visualized in 50/54 patients (92.6%). Of these, detailed evaluation of the locus could be performed in 41. In five patients attempted 3D-IDUS, the relationship between the lesion and its location was readily grasped. Conclusion:, IDUS of the gallbladder is superior for diagnosing minute images. Improvement on the device will further increase its usefulness. [source] Geomorphic and sedimentological signature of a two-phase outburst ,ood from moraine-dammed Queen Bess Lake, British Columbia, CanadaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 1 2005Jane A. Kershaw Abstract On 12 August 1997, the lower part of Diadem Glacier in the southern Coast Mountains of British Columbia fell into Queen Bess Lake and produced a train of large waves. The waves overtopped the broad end moraine at the east end of the lake and ,ooded the valley of the west fork of Nostetuko River. The displacement waves also incised the out,ow channel across the moraine. Stratigraphic and sedimentologic evidence supports the conclusion that the ,ood had two phases, one related to wave overtopping and a second to breach formation. Empirical equations were used to calculate the peak discharge of the ,ood at various points along the west fork of the Nostetuko valley and to describe the attenuation of the ,ood wave. The velocity of the ,ood was also calculated to determine the time it took for the ,ood to reach the main fork of Nostetuko River. The highest peak discharges were achieved in the upper reach of the valley during the displacement phase of the ,ood. Peak discharge declined rapidly just below the moraine dam, with little change thereafter for approximately 7 km. Empirical formulae and boulder measurements indicate a rise in peak discharge in the lower part of the west fork valley. We suggest that ,ow in the upper part of the valley records the passage of two separate ,ood peaks and that the rise in discharge in the lower part of the valley is due to amalgamation of the wave and breach peaks. Hydraulic ponding in con,ned reaches of the valley extended the duration of the ,ood. In addition, erosion of vegetation and sediment in the channel and valley sides may also have exerted an in,uence on the duration and nature of ,ooding. Sediments were deposited both upstream and downstream of channel constrictions and on a large fan extending out into the trunk Nostetuko River valley. This study extends our understanding of the variety and complexity of outburst ,oods from naturally dammed lakes. It also shows that simple empirical and other models for estimating peak discharges of outburst ,oods are likely to yield erroneous results. Copyright © 2005 John Wiley & Sons, Ltd. [source] Assessing the impact of riparian processes on streambank stability,ECOHYDROLOGY, Issue 3 2009Eddy J. Langendoen Abstract The series of biennial United States (US) National Water Quality Inventory surveys shows no reduction in the percentage of degraded miles of streams since the early 1990s despite an exponential increase in river restoration projects to improve water quality, enhance in-stream habitat and manage the riparian zone. This may suggest that many river restoration projects fail to achieve their objectives. This is partly due to a lack of understanding of the dynamics of the degraded riverine system and its interaction with the riparian zone. These projects could, therefore, benefit from using proven models of stream and riparian processes to guide restoration design and to evaluate indicators of ecological integrity. The US Department of Agriculture has developed two such models: the channel evolution computer model CONCEPTS and the riparian ecosystem model REMM. These models have been integrated to evaluate the impact of edge-of-field and riparian conservation measures on stream morphology and water quality. Vegetative riparian conservation measures are commonly used to stabilize failing streambanks. The shear strength of bank soils is greatly affected by the degree of saturation of the soils and root reinforcement provided by riparian vegetation. The integrated model was used to study the effectiveness of woody and herbaceous riparian buffers in controlling streambank erosion of an incised stream in northern Mississippi. Comparison of model results with observations showed that pore-water pressures are accurately predicted in the upper part of the streambank, away from the groundwater table. Simulated pore-water pressures deviate from those observed lower in the streambank near the phreatic surface. These discrepancies are mainly caused by differences in the simulated location of the phreatic surface and simulated evapotranspiration in case of the woody buffer. The modelling exercise further showed that a coarse rooting system, e.g. as provided by trees, significantly reduced bank erosion rates for this deeply incised stream. Published in 2009 by John Wiley & Sons, Ltd. [source] Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.)ECOLOGY OF FRESHWATER FISH, Issue 2 2010P. Gustafsson Gustafsson P, Bergman E, Greenberg LA. Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.).Ecology of Freshwater Fish 2010: 19: 170,177. © 2010 John Wiley & Sons A/S Abstract ,, Terrestrial invertebrate subsidies are believed to be important energy sources for drift-feeding salmonids. Despite this, size-specific use of and efficiency in procuring this resource have not been studied to any great extent. Therefore, we measured the functional responses of three size classes of wild brown trout Salmo trutta (0+, 1+ and ,2+) when fed either benthic- (Gammarus sp.) or surface-drifting prey (Musca domestica) in laboratory experiments. To test for size-specific prey preferences, both benthic and surface prey were presented simultaneously by presenting the fish with a constant density of benthic prey and a variable density of surface prey. The results showed that the functional response of 0+ trout differed significantly from the larger size classes, with 0+ fish having the lowest capture rates. Capture rates did not differ significantly between prey types. In experiments when both prey items were presented simultaneously, capture rate differed significantly between size classes, with larger trout having higher capture rates than smaller trout. However, capture rates within each size class did not change with prey density or prey composition. The two-prey experiments also showed that 1+ trout ate significantly more surface-drifting prey than 0+ trout. In contrast, there was no difference between 0+ and ,2+ trout. Analyses of the vertical position of the fish in the water column corroborated size-specific foraging results: larger trout remained in the upper part of the water column between attacks on surface prey more often than smaller trout, which tended to seek refuge at the bottom between attacks. These size-specific differences in foraging and vertical position suggest that larger trout may be able to use surface-drifting prey to a greater extent than smaller conspecifics. [source] Effect of habitat fragmentation on spawning migration of brown trout (Salmo trutta L.)ECOLOGY OF FRESHWATER FISH, Issue 3 2006C. Gosset Abstract , Human-induced habitat alteration is one of the main causes of the decline of freshwater fish populations. The watershed of the River Bidasoa (Spain) is an example of heavily fragmented habitat. The local brown trout (Salmo trutta L.) population is disturbed, with evidence of poor recruitment as well as low adult densities in the main stem. Forty male and female adult migratory trout were tagged with external or internal radio transmitters and released. Fixed stations with data loggers and mobile antennae were used with daily surveys to track fish movements during the migration and spawning period (3 months). Migration distances did not exceed 10 km, and half of the fish never entered a tributary in the study area. Fragmentation because of weirs on the main stem apparently prevented fish from reaching their spawning destination. Fish that entered the tributaries were first confronted with an accessibility problem because of low discharge. However, each fish chose one tributary, without making attempts to run up in other tributaries. Once in the tributary, fish were restrained in their upstream movements by dams. The study area appeared to be isolated from the vast upper part of the watershed. Within the study area, upper parts of tributaries also seemed strongly disconnected from the main stem. This study illustrates the negative impact of river fragmentation on S. trutta migration pattern. Population sustainability can be directly affected through the low availability of spawning grounds for migratory fish. Long-term effects of fragmentation may cause reproductive isolation within watersheds, which in the case of trout also means isolated phenotypic population units. [source] Niche separation of ammonia-oxidizing bacteria across a tidal freshwater marshENVIRONMENTAL MICROBIOLOGY, Issue 11 2008Hendrikus J. Laanbroek Summary Like many functional groups or guilds of microorganisms, the group of ammonia-oxidizing bacteria (AOB) consists of a number of physiologically different species or lineages. These physiological differences suggest niche differentiation among these bacteria depending on the environmental conditions. Species of AOB might be adapted to different zones in the flooding gradient of a tidal marsh. This issue has been studied by sampling sediments from different sites and depths within a tidal freshwater marsh along the river Scheldt near the village of Appels in Belgium. Samples were taken in February, April, July and October 1998. Communities of AOB in the sediment were analysed on the basis of the 16S rRNA gene by application of polymerase chain reaction in combination with denaturing gradient gel electrophoresis (DGGE). In addition, moisture content and concentrations of ammonium and nitrate were determined as well as the potential ammonia-oxidizing activities. Six different DGGE bands belonging to the ,-subclass of the Proteobacteria were observed across the marsh. The community composition of AOB was determined by the elevation in the flooding gradient as well as by the sampling depth. The presence of plants was less important for the community composition of AOB. DGGE bands affiliated with the Nitrosospira lineage were mostly found in the upper part of the marsh and in the deeper layers of the sediment. Two of the three DGGE bands related to the Nitrosomonas oligotropha lineage were more broadly distributed over the marsh, but were predominantly found in the upper layers of the sediment. Members of the environmental Nitrosomonas lineage 5 were predominantly detected in the deeper layers in the lower parts of the marsh. Potential driving factors for niche differentiation are discussed. [source] Limits of life in MgCl2 -containing environments: chaotropicity defines the windowENVIRONMENTAL MICROBIOLOGY, Issue 3 2007John E. Hallsworth Summary The biosphere of planet Earth is delineated by physico-chemical conditions that are too harsh for, or inconsistent with, life processes and maintenance of the structure and function of biomolecules. To define the window of life on Earth (and perhaps gain insights into the limits that life could tolerate elsewhere), and hence understand some of the most unusual biological activities that operate at such extremes, it is necessary to understand the causes and cellular basis of systems failure beyond these windows. Because water plays such a central role in biomolecules and bioprocesses, its availability, properties and behaviour are among the key life-limiting parameters. Saline waters dominate the Earth, with the oceans holding 96.5% of the planet's water. Saline groundwater, inland seas or saltwater lakes hold another 1%, a quantity that exceeds the world's available freshwater. About one quarter of Earth's land mass is underlain by salt, often more than 100 m thick. Evaporite deposits contain hypersaline waters within and between their salt crystals, and even contain large subterranean salt lakes, and therefore represent significant microbial habitats. Salts have a major impact on the nature and extent of the biosphere, because solutes radically influence water's availability (water activity) and exert other activities that also affect biological systems (e.g. ionic, kosmotropic, chaotropic and those that affect cell turgor), and as a consequence can be major stressors of cellular systems. Despite the stressor effects of salts, hypersaline environments can be heavily populated with salt-tolerant or -dependent microbes, the halophiles. The most common salt in hypersaline environments is NaCl, but many evaporite deposits and brines are also rich in other salts, including MgCl2 (several hundred million tonnes of bischofite, MgCl2·6H2O, occur in one formation alone). Magnesium (Mg) is the third most abundant element dissolved in seawater and is ubiquitous in the Earth's crust, and throughout the Solar System, where it exists in association with a variety of anions. Magnesium chloride is exceptionally soluble in water, so can achieve high concentrations (> 5 M) in brines. However, while NaCl-dominated hypersaline environments are habitats for a rich variety of salt-adapted microbes, there are contradictory indications of life in MgCl2 -rich environments. In this work, we have sought to obtain new insights into how MgCl2 affects cellular systems, to assess whether MgCl2 can determine the window of life, and, if so, to derive a value for this window. We have dissected two relevant cellular stress-related activities of MgCl2 solutions, namely water activity reduction and chaotropicity, and analysed signatures of life at different concentrations of MgCl2 in a natural environment, namely the 0.05,5.05 M MgCl2 gradient of the seawater : hypersaline brine interface of Discovery Basin , a large, stable brine lake almost saturated with MgCl2, located on the Mediterranean Sea floor. We document here the exceptional chaotropicity of MgCl2, and show that this property, rather than water activity reduction, inhibits life by denaturing biological macromolecules. In vitro, a test enzyme was totally inhibited by MgCl2 at concentrations below 1 M; and culture medium with MgCl2 concentrations above 1.26 M inhibited the growth of microbes in samples taken from all parts of the Discovery interface. Although DNA and rRNA from key microbial groups (sulfate reducers and methanogens) were detected along the entire MgCl2 gradient of the seawater : Discovery brine interface, mRNA, a highly labile indicator of active microbes, was recovered only from the upper part of the chemocline at MgCl2 concentrations of less than 2.3 M. We also show that the extreme chaotropicity of MgCl2 at high concentrations not only denatures macromolecules, but also preserves the more stable ones: such indicator molecules, hitherto regarded as evidence of life, may thus be misleading signatures in chaotropic environments. Thus, the chaotropicity of MgCl2 would appear to be a window-of-life-determining parameter, and the results obtained here suggest that the upper MgCl2 concentration for life, in the absence of compensating (e.g. kosmotropic) solutes, is about 2.3 M. [source] Microsite-dependent changes in methanogenic populations in a boreal oligotrophic fenENVIRONMENTAL MICROBIOLOGY, Issue 11 2003Pierre E. Galand Summary Wetlands, including peatlands, are the main source of natural methane emission. Well-defined fen microsites have different methane emissions rates, but it is not known whether the methane-producing Archaea communities vary at these sites. Possible horizontal variations of communities, in a natural oligotrophic fen, were analysed by characterizing the methanogens from two well-defined microsites: Eriophorum lawn and Hummock. Community structures were studied at two different layers of the fen, showing, respectively, high and low methane production. The structure of methanogen populations was determined using molecular techniques targeting the 16SrRNA gene and combined denaturing gradient gel electrophoresis (DGGE) and restriction fragment length polymorphism (RFLP) analysis. Results subjected to non-metric multidimensional scaling (MDS), diversity indices calculation and phylogenetic analysis revealed that upper layer communities changed with site while deeper layer communities remained the same. Phylogenetic analyses revealed six different clusters of sequences grouping with only two known orders of methanogens. Upper layers of Hummock were dominated by sequences clustering with members of Methanomicrobiales and sequences dominating the upper part of the Eriophorum lawn were related to members of the order Methanosarcinales. Novel methanogenic sequences were found at both sites at both depths. Vegetation characterizing the microsites probably influences the microbial communities in the layers of the fen where methane is produced. [source] Different portions of the maize root system host Burkholderia cepacia populations with different degrees of genetic polymorphismENVIRONMENTAL MICROBIOLOGY, Issue 1 2000Luigi Chiarini In order to acquire a better understanding of the spatial and temporal variations of genetic diversity of Burkholderia cepacia populations in the rhizosphere of Zea mays, 161 strains were isolated from three portions of the maize root system at different soil depths and at three distinct plant growth stages. The genetic diversity among B. cepacia isolates was analysed by means of the random amplified polymorphic DNA (RAPD) technique. A number of diversity indices (richness, Shannon diversity, evenness and mean genetic distance) were calculated for each bacterial population isolated from the different root system portions. Moreover, the analysis of molecular variance ( amova) method was applied to estimate the genetic differences among the various bacterial populations. Our results showed that, in young plants, B. cepacia colonized preferentially the upper part of the root system, whereas in mature plants, B. cepacia was mostly recovered from the terminal part of the root system. This uneven distribution of B. cepacia cells among different root system portions partially reflected marked genetic differences among the B. cepacia populations isolated along maize roots on three distinct sampling occasions. In fact, all the diversity indices calculated indicated that genetic diversity increased during plant development and that the highest diversity values were found in mature maize plants, in particular in the middle and terminal portions of the root system. Moreover, the analysis of RAPD patterns by means of the amova method revealed highly significant divergences in the degree of genetic polymorphism among the various B. cepacia populations. [source] Water-repellent soil and its relationship to granularity, surface roughness and hydrophobicity: a materials science viewEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2005G. McHale Summary Considerable soil water repellency has been observed at a wide range of locations worldwide. The soil exhibiting water repellency is found within the upper part of the soil profile. The reduced rate of water infiltration into these soils leads to severe runoff erosion, and reduction of plant growth. Soil water repellency is promoted by drying of soil, and can be induced by fire or intense heating of soil containing hydrophobic organic matter. Recent studies outside soil science have shown how enhancement of the natural water repellency of materials, both porous and granular, by surface texture (i.e. surface roughness, pattern and morphology) into super-hydrophobicity is possible. The similarities between these super-hydrophobic materials and observed properties of water-repellent soil are discussed from a non-soil scientist, materials-based perspective. A simple model is developed for a hydrophobic granular surface and it is shown that this can provide a mechanism for enhancement of soil water repellency through the relative size and spacing of grains and pores. The model provides a possible explanation for why soil water repellency should be more prevalent under dry conditions than wet. Consequences for water runoff, raindrop splash and soil erosion are discussed. [source] Distribution of microbial biomass and phospholipid fatty acids in Podzol profiles under coniferous forestEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2000H. Fritze Summary Microbial-derived phospholipid fatty acids (PLFAs) can be used to characterize the microbial communities in soil without the need to isolate individual fungi and bacteria. They have been used to assess microbial communities of humus layers under coniferous forest, but nothing is known of their distribution in the deeper soil. To investigate the vertical distribution we sampled nine Podzol profiles on a 100-m-long transect in a coniferous forest and analysed for their microbial biomass and PLFA pattern to a depth of 0.4 m. The transect covered a fertility gradient from Vaccinium vitis-idaea forest site type to Vaccinium myrtillus forest site type. The cores were divided into humus (O) and eluvial (E) layers and below that into 10-cm sections and designated as either illuvial (B) or parent material (C), or as a combination (BC). Two measures of microbial biomass analyses were applied: substrate-induced respiration (SIR) to determine microbial biomass C (Cmic), and the sum of the extracted microbial-derived phospholipid fatty acids (totPLFA). The soil fertility had no effect on the results. The Cmic correlated well with totPLFA (r=,0.86). The microbial biomass decreased with increasing depth. In addition the PLFA pattern changed with increased depth as assessed with principal component analysis, indicating a change in the microbial community structure. The composition of the PLFAs in the O layer differed from that in the E layer and both differed from the upper part of the B layer and from the rest of the BC layers. The deeper parts of the B layer (BC1, BC2 and BC3) were similar to one other. The O layer had more 18:2,6, a PLFA indicator of fungi, whereas the E layer contained relatively more of the PLFAs 16:1,9, 18:1,7 and cy19:0 common in gram-negative bacteria. With increased depth the relative amount of 10Me18:0, the PLFA indicator for actinomycetes, increased. We conclude that the PLFA method is a promising discriminator between the microbial community structures of the horizons in Podzols. [source] Surface podzolization in Cambisols under deciduous forest in the Belgian loess beltEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2000V. Brahy Summary Surface podzolization involves the migration of metal,humus complexes to a depth of a few centimetres. In acid soils derived from loess, this process has been diagnosed mainly by morphological observation. We investigated this process in a toposequence of Luvisols and Cambisols on loess using selective extraction and mineralogical data as well as characteristics of the leaf litter. The humus type (O and OAh horizons) is a moder in the three Luvisols and one of the Cambisols, whereas it is a fibrimor in the two other Cambisols. The contents in total alkaline and alkaline-earth cations range from 35 to 60 cmolc kg,1 in the fibrimor and from 40 to 90 cmolc kg,1 in the moder humus. In the two Cambisols with fibrimor smectite occurs in the clay fraction of the Ah horizon; Fe,humus complexes seem to have moved, but no more than 9 cm, from the Ah to the AB horizon beneath. Relative to the Ah horizon, the upper part of the AB has larger tetraborate-extractable Fe/Al ratio and optical density of the oxalate extract. Such features converge to diagnose surface podzolization in the Cambisols with fibrimor. However, they were not detected in the Cambisol and Luvisols with moder. In the two Cambisols with fibrimor, surface podzolization is consistent with (i) their smaller iron content, (ii) their more advanced weathering stage and (iii) their lower acid neutralizing capacity. [source] Axial Rotation of the Lower Human Spine by Rhythmic Torques Automatically Generated at the Resonant FrequencyEXPERIMENTAL PHYSIOLOGY, Issue 3 2003E. Geoffrey Walsh Subjects sat on a ,Balans' chair supported by the shaft of a large torque generator. The lower but not the upper part of the body was free to make to/fro movements maintained by feeding back a modified velocity signal to the generator. The stiffness could be increased by the use of a position signal. Using the equations for a torsion pendulum the good linearity observed in relationship to the applied forces allowed stiffness, inertia, damping, critical damping and the damping factor to be determined in absolute terms. The method enables parameters relevant to back function and problems to be evaluated. Eleven adults acted as subjects. [source] Übersicht über die Sporenassoziationen (lepidophyta - bis pusilla -Zone) aus dem Unterkarbon der Bohrung Neuenkirchen 2/1973 (Insel Rügen, NE-Deutschland)FOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 1 2001Gusti Burmann Abstract Es wird die Sporenzonierung für das Tournai (einschließlich der Grenzschichten) der Bohrung Neuenkirchen 2/73 auf der Insel Rügen (NE-Deutschland) vorgelegt - von der lepidophyta -Zone var. minor -Subzone des Tnla des obersten Devons bis zur pusilla -Zone des tieferen Visé. Das Profit wird verglichen mit der Zonenabfolge aus der Bohrung Wiek 4/70 (Burmann 1975). Zur lepidophyta -Zone liegen vergleichbare Daten aus dem Harz vor (Burmann 1976). Die untersuchte Abfolge von Sporenzonen umfasst die lepidophyta -Zone mit der var. minor -Subzone (höheres Tnla); PA (pusillites-asperitis; Tn1b); NRH (nitidus-rarituberculatus-hederatus; Tn1b-Tn2); ND (nitidus-distinctus; Tn2); RM (rarituber-culatus-minutissimus; tieferes Tn3); CM (claviger-macra; höheres Tn3); Pu (pusilla; V1a+V1b; Obergrenze der Pu-Zone nicht erfasst). Die stratigraphische Einbindung der Sporenzonen erfolgte durch makrofaunistische Datierungen. Die Pu-Zone ist in beiden Bohrungen untergliederbar durch einen Horizont mit Gloeocapsamorpha. Lower Carboniferous spore assemblages (lepidophyta zone to pusilla zone) in the Neuenkirchen 2/1973 borehole of Rügen Island, NE Germany A spore zonation is given for the Tournaisian sequence of the Neuenkirchen 2/73 borehole on the island of Rügen (NE Germany). The deposits range from the lepidophyta zone var. minor subzone of the uppermost Famennian (Tnla) to the pusilla zone of the basal Viséan. The results are compared with the miospore zonation of the borehole Wiek 4 (Burmann 1975), and comparable dates for the lepidophyta zone from the Harz mountains (Burmann 1976). In ascending order the miospore zones examined are: lepidophyta zone with var. minor subzone (upper part of Tnla); PA (pusillites-asperitis; Tnlb); NRH (nitidus-rarituberculatus-hederatus; Tnlb-Tn2): ND (nitidus-distinctus; Tn2); RM (rarituber-culatus-minutissimus; lower part of Tn3): CM (claviger-macra; upper part of Tn3); Pu (pusilla; V1a+V1b; the upper boundary of the Pu zone is not determined). The stratigraphy of the spore zones is also compared with the macrofaunal data. The Pu zone in both boreholes is divided into two parts by a horizon with Gloeocapsamorpha. [source] Catchment- and site-scale influences of forest cover and longitudinal forest position on the distribution of a diadromous fishFRESHWATER BIOLOGY, Issue 3 2005HANS S. EIKAAS Summary 1. The hydrologic connectivity between landscape elements and streams means that fragmentation of terrestrial habitats could affect the distribution of stream faunas at multiple spatial scales. We investigated how catchment- and site-scale influences, including proportion and position of forest cover within a catchment, and presence of riparian forest cover affected the distribution of a diadromous fish. 2. The occurrence of koaro (Galaxias brevipinnis) in 50-m stream reaches with either forested or non-forested riparian margins at 172 sites in 24 catchments on Banks Peninsula, South Island, New Zealand was analysed. Proportions of catchments forested and the dominant position (upland or lowland) of forest within catchments were determined using geographical information system spatial analysis tools. 3. Multivariate analysis of variance indicated forest position and proportion forested at the catchment accounted for the majority of the variation in the overall proportion of sites in a catchment with koaro. 4. Where forest was predominantly in the lower part of the catchments, the presence of riparian cover was important in explaining the proportion of sites with koaro. However, where forest was predominantly in the upper part of the catchment, the effect of riparian forest was not as strong. In the absence of riparian forest cover, no patterns of koaro distribution with respect to catchment forest cover or forest position were detected. 5. These results indicate that landscape elements, such as the proportion and position of catchment forest, operating at catchment-scales, influence the distribution of diadromous fish but their influence depends on the presence of riparian vegetation, a site-scale factor. [source] Transmission Electron Microscopy and UV,vis,IR Spectroscopy Analysis of the Diameter Sorting of Carbon Nanotubes by Gradient Density UltracentrifugationADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Romain Fleurier Abstract Diameter separation of single-walled carbon nanotubes is achieved via the density gradient ultracentrifugation process. Statistical analysis of the separated samples is performed using high-resolution transmission electron microscopy (HRTEM). The evolution of the diameter distribution with respect to the gradient density is extracted by analyzing hundreds of HRTEM images, and the results are found to be consistent with those estimated by UV,vis,IR spectroscopy. The efficiency of the separation process can be quantitatively characterized by the standard deviation of the diameter distribution, which is determined from the TEM analyses. This particular study indicated that for electric arc nanotubes dispersed in sodium cholate, diameter sorting is more efficient in the upper part of the gradient. [source] New archaeo-stratigraphic data for the TD6 level in relation to Homo antecessor (Lower Pleistocene) at the site of Atapuerca, north-central SpainGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2003Antoni Canals The sediments of the TD6 level of Gran Dolina Cave at Sierra de Atapuerca, Burgos, Spain, consist of a series of mud flows with angular clasts. The TD6 deposit has two parts: an upper part, known as the Aurora stratum, which yields Homo antecessor remains, and a lower part with rather homogeneous sediment. The excavation of TD6 level did not reveal a sequence of diachronic occupations. Instead, the contextual and stratigraphic studies permitted us to describe and delimit the micro-units forming the TD6 deposit. The study of the distribution of archaeological remains based on vertical archaeological profiles, using an archaeo-stratigraphic method, allowed us to document the occurrence of a series of archaeological levels within the apparent homogeneous deposit. Variations in the density of archaeological remains along the archaeo-stratigraphic levels permitted us to define two occupational cycles in TD6. These cycles seemingly show increased activities through time, culminating in the Aurora level with the presence of cannibalized Homo antecessor remains. © 2003 Wiley Periodicals, Inc. [source] Natural-gradient tracer experiments in epikarst: a test study in the Acqua dei Faggi experimental site, southern ItalyGEOFLUIDS (ELECTRONIC), Issue 3 2008E. PETRELLA Abstract Two natural-gradient tracer experiments were carried out using borehole fluorometers in order to characterize the internal structure of epikarstic horizons and analyze subsurface flow within these high-conductivity layers. The experiments were carried out in a test site in southern Italy where the epikarst is made up of an upper part with pervasive karstification and a lower part without pervasive karstification. Injection and observation boreholes were 6.9 m apart. An initial experiment demonstrated that wider (conduits) and narrower (fractures and bedding planes) openings coexist in a well-connected network within the lower epikarst. The adjusted aperture of the opening network (105 ,m) suggests that conduits are subordinately developed. The lower epikarstic horizon is hydraulically similar to granular porous media and Darcy's law can be applied to describe groundwater flow. A small value of longitudinal dispersivity (0.13 m) shows that variations in the velocity field in the direction of flow are less significant than those typical of carbonate systems at the same experiment scale. A second experiment demonstrated that longitudinal dispersivity (2.42 m) in the upper epikarst is in agreement with findings in other carbonates at the same experiment scale. However, despite the higher dispersivity and more pervasive karstification, the mean tracer velocity (3.7 m day,1) in the upper epikarst is slightly lower than the velocity in the lower epikarst (13.6 m day,1). [source] Infiltration of basinal fluids into high-grade basement, South Norway: sources and behaviour of waters and brinesGEOFLUIDS (ELECTRONIC), Issue 1 2003S. A. Gleeson Abstract Quartz veins hosted by the high-grade crystalline rocks of the Modum complex, Southern Norway, formed when basinal fluids from an overlying Palaeozoic foreland basin infiltrated the basement at temperatures of c. 220°C (higher in the southernmost part of the area). This infiltration resulted in the formation of veins containing both two-phase and halite-bearing aqueous fluid inclusions, sometimes with bitumen and hydrocarbon inclusions. Microthermometric results demonstrate a very wide range of salinities of aqueous fluids preserved in these veins, ranging from c. 0 to 40 wt% NaCl equivalent. The range in homogenization temperatures is also very large (99,322°C for the entire dataset) and shows little or no correlation with salinity. A combination of aqueous fluid microthermometry, halogen geochemistry and oxygen isotope studies suggest that fluids from a range of separate aquifers were responsible for the quartz growth, but all have chemistries comparable to sedimentary formation waters. The bulk of the quartz grew from relatively low ,18O fluids derived directly from the basin or equilibrated in the upper part of the basement (T < 200°C). Nevertheless, some fluids acquired higher salinities due to deep wall-rock hydration reactions leading to salt saturation at high temperatures (>300°C). The range in fluid inclusion homogenization temperatures and densities, combined with estimates of the ambient temperature of the basement rocks suggests that at different times veins acted as conduits for influx of both hotter and colder fluids, as well as experiencing fluctuations in fluid pressure. This is interpreted to reflect episodic flow linked to seismicity, with hotter dry basement rocks acting as a sink for cooler fluids from the overlying basin, while detailed flow paths reflected local effects of opening and closing of individual fractures as well as reaction with wall rocks. Thermal considerations suggest that the duration of some flow events was very short, possibly in the order of days. As a result of the complex pattern of fracturing and flow in the Modum basement, it was possible for shallow fluids to penetrate basement rocks at significantly higher temperatures, and this demonstrates the potential for hydrolytic weakening of continental crust by sedimentary fluids. [source] Palynological evidence for Pennsylvanian (Late Carboniferous) vegetation change in the Sydney Coalfield, eastern CanadaGEOLOGICAL JOURNAL, Issue 4 2010Tatyana K. Dimitrova Abstract The palynology of clastic samples from seven stratigraphical levels in the late Moscovian Sydney Mines Formation, exposed along the shore at Bras d'Or, Nova Scotia, has been investigated. Most of the samples were from roof shales of major coals; the one sample that was not yielded a much higher proportion of pollen derived from extra-basinal vegetation. The four stratigraphically lower roof shale samples yielded essentially similar palynological spectra, with 39,±,4% lycophytes, 9,±,4% sphenophylls, 23,±,4% tree-ferns, 12,±,4% other ferns and 5,±,3% cordaites. The palynology of the upper part of the investigated succession suggests a shift in vegetation towards one favouring more marattialean tree-ferns, cordaites and conifers, and fewer lycophytes. This correlates with changes in drainage patterns as the alluvial plain migrated seawards and thus changed water tables. No evidence was found to suggest significant climate change at this time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Stratigraphic and structural evolution of the Blue Nile Basin, Northwestern Ethiopian PlateauGEOLOGICAL JOURNAL, Issue 1 2009N. DS. Abstract The Blue Nile Basin, situated in the Northwestern Ethiopian Plateau, contains ,1400,m thick Mesozoic sedimentary section underlain by Neoproterozoic basement rocks and overlain by Early,Late Oligocene and Quaternary volcanic rocks. This study outlines the stratigraphic and structural evolution of the Blue Nile Basin based on field and remote sensing studies along the Gorge of the Nile. The Blue Nile Basin has evolved in three main phases: (1) pre-sedimentation phase, include pre-rift peneplanation of the Neoproterozoic basement rocks, possibly during Palaeozoic time; (2) sedimentation phase from Triassic to Early Cretaceous, including: (a) Triassic,Early Jurassic fluvial sedimentation (Lower Sandstone, ,300,m thick); (b) Early Jurassic marine transgression (glauconitic sandy mudstone, ,30,m thick); (c) Early,Middle Jurassic deepening of the basin (Lower Limestone, ,450,m thick); (d) desiccation of the basin and deposition of Early,Middle Jurassic gypsum; (e) Middle,Late Jurassic marine transgression (Upper Limestone, ,400,m thick); (f) Late Jurassic,Early Cretaceous basin-uplift and marine regression (alluvial/fluvial Upper Sandstone, ,280,m thick); (3) the post-sedimentation phase, including Early,Late Oligocene eruption of 500,2000,m thick Lower volcanic rocks, related to the Afar Mantle Plume and emplacement of ,300,m thick Quaternary Upper volcanic rocks. The Mesozoic to Cenozoic units were deposited during extension attributed to Triassic,Cretaceous NE,SW-directed extension related to the Mesozoic rifting of Gondwana. The Blue Nile Basin was formed as a NW-trending rift, within which much of the Mesozoic clastic and marine sediments were deposited. This was followed by Late Miocene NW,SE-directed extension related to the Main Ethiopian Rift that formed NE-trending faults, affecting Lower volcanic rocks and the upper part of the Mesozoic section. The region was subsequently affected by Quaternary E,W and NNE,SSW-directed extensions related to oblique opening of the Main Ethiopian Rift and development of E-trending transverse faults, as well as NE,SW-directed extension in southern Afar (related to northeastward separation of the Arabian Plate from the African Plate) and E,W-directed extensions in western Afar (related to the stepping of the Red Sea axis into Afar). These Quaternary stress regimes resulted in the development of N-, ESE- and NW-trending extensional structures within the Blue Nile Basin. Copyright © 2008 John Wiley & Sons, Ltd. [source] Late Miocene fish otoliths from the Colombacci Formation (Northern Apennines, Italy): implications for the Messinian ,Lago-mare' eventGEOLOGICAL JOURNAL, Issue 5 2006Giorgio Carnevale Abstract A fish otolith assemblage from the Messinian ,Lago-mare' deposits of the Colombacci Formation cropping out in the Montecalvo in Foglia Syncline, Marche, central Italy, is described. The assemblage displays a low diversity and consists of seven taxa belonging to three families: the Gobiidae, Myctophidae and Sciaenidae. Sciaenid otoliths are the most abundant elements representing 88% of the entire assemblage. The palaeoecological analysis reveals a coastal shallow marine environment strongly influenced by continental outflow. The low diversity and high abundance of the euryecious sciaenids are indicative of a very simplified food web, which probably represented an ecological response to the fluctuating environmental parameters and available food resources. The fish remains documented here provide an unambiguous evidence that normal marine conditions were present in the Mediterranean, at least in the upper part of the ,Lago-mare' event, and unquestionably demonstrate that the marine refilling preceded the Mio-Pliocene boundary. These findings clearly demonstrate that fishes, because of their mobility and migratory behaviour, represent a useful tool for the large-scale interpretation of the environmental conditions of the Messinian Mediterranean water body. The necessity of a new scenario of palaeoenvironmental evolution for the post-evaporitic Messinian of the Mediterranean is also discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Stratigraphy of upper Viséan carbonate platform rocks in the Carlow area, southeast IrelandGEOLOGICAL JOURNAL, Issue 1 2005P. Cózar Abstract The stratigraphy of the upper Viséan (Asbian to Brigantian) carbonate succession in southeast Ireland is revised on the basis of seven quarry and two borehole sections. Six lithological units have been distinguished, two units (units 1 and 2) in the upper Asbian Ballyadams Formation, and four units (units 4 to 6) in the Brigantian Clogrenan Formation (both formations are dated precisely using foraminiferans, calcareous algae and rugose corals). The boundary between the Ballyadams and Clogrenan formations is redefined 19,m below the horizon proposed by the Geological Survey of Ireland, and thus, lithological characteristics of both formations are redescribed. The upper part of the Ballyadams Formation is characterized by well-developed large-scale cyclicity, with common subaerial exposure surfaces. Fine- to medium-grained thin-bedded limestones with thin shales occur in the lower part of cycles, passing up into medium-grained pale grey massive limestones in the upper part. The Clogrenan Formation is composed mainly of medium- to coarse-grained thick limestone beds with variable presence of shales; but no large-scale cyclicity. There is a decrease in the number of subaerial exposure surfaces towards the top of the formation and common chert nodules; macrofauna occurs mostly concentrated in bands. The six units recognized in the Carlow area are comparable with other units described for the same time interval (Asbian,Brigantian) from south and southwest Ireland, demonstrating the existence of a stable platform for most parts of southern Ireland, controlled principally by glacioeustatics. Copyright © 2004 John Wiley & Sons, Ltd. [source] Origin of metamorphic soles and their post-kinematic mafic dyke swarms in the Antalya and Lycian ophiolites, SW TurkeyGEOLOGICAL JOURNAL, Issue 3-4 2003Ö. Faruk Çeli Abstract The Antalya and Lycian ophiolites are situated in the western part of the Tauride belt (SW Turkey). Ophiolite-related metamorphic sole rocks in the Tauride belt are observed either at the base of the tectonites or in mélange units. Geochemical observations from the metamorphic sole rocks of Köyce,iz ophiolite indicate three different geochemical affinities: mid-ocean ridge basalt (MORB), island-arc tholeiite (IAT) and within-plate basalt (WPB) or seamount are present at the base of the Lycian ophiolites. The sole rocks of the ophiolite are made up of amphibolite, comprising mainly amphibole, pyroxene and plagioclase. Below the amphibolites are epidote-bearing rocks and, at the base, micaschists. The metamorphic sole below ophiolites exhibits an inverted metamorphic zonation. Very strong deformation within kyanite-garnet-bearing micaschists located far from the peridotites was observed, whereas the upper part of the metamorphic sole (near the contact with the peridotites) present relatively less deformation than the lower part. The metamorphic sole rocks of the Lycian ophiolite are cross-cut by some doleritic dykes with a typical greenschist facies mineral assemblage. However, while the metamorphic sole rocks exhibit well-developed lineation and foliation; the dykes lack such structures. Copyright © 2003 John Wiley & Sons, Ltd. [source] Lagoon,tidal flat sedimentation in an epeiric sea: Proterozoic Bhander Group, Son Valley, IndiaGEOLOGICAL JOURNAL, Issue 2 2001Chandan Chakraborty Abstract The Bhander Group, the uppermost stratigraphic unit of the Proterozoic Vindhyan Supergroup in Son Valley, exhibits in its upper part a 550,m thick, muddy siliciclastic succession characterized by features indicative of deposition in a wave-affected coastal, lagoon,tidal flat environment suffering repeated submergence and emergence. The basic architecture of the deposit is alternation of centimetre- to decimetre-thick sheet-like interbeds of coarser clastics (mainly sandstone) and decimetre-thick mudstones. The coarser interlayers are dominated by a variety of ripple-formed laminations. The preserved ripple forms on bed-top surfaces and their internal lamination style suggest both oscillatory and combined flows for their formation. Interference, superimposed, ladder-back and flat-topped ripples are also common. Synsedimentary cracks, wrinkle marks, features resembling rain prints and adhesion structures occur in profusion on bed-top surfaces. Salt pseudomorphs are also present at the bases of beds. The mudstone intervals represent suspension settlement and show partings with interfaces characterized by synsedimentary cracks. It is inferred that the sediments were deposited on a coastal plain characterized by a peritidal (supratidal,intertidal) flat and evaporative lagoon suffering repeated submergence and emergence due to storm-induced coastal setup and setdown in addition to tidal fluctuations. The 550,m thick coastal flat succession is surprisingly devoid of any barrier bar deposits and also lacks shoreface and shelfal strata. The large areal extent of the coastal flat succession (c. 100,000,km2) and its great thickness indicate an extremely low-gradient epeiric basin characterized by an extensive coastal flat sheltered from the deeper marine domain. It is inferred that the Bhander coastal flat was protected from the open sea by the Bundelkhand basement arch to the north of the Vindhyan basin, instead of barrier bars. Such a setting favoured accumulation of a high proportion of terrigenous mud in the coastal plain, in contrast to many described examples from the Proterozoic. Copyright © 2001 John Wiley & Sons, Ltd. [source] Three-dimensional seismic structure beneath the Australasian region from refracted wave observationsGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2000Y. Kaiho The earthquakes in the seismicity belt extending through Indonesia, New Guinea, Vanuatu and Fiji to the Tonga,Kermadec subduction zone recorded at the 65 portable broad-band stations deployed during the Skippy experiment from 1993,1996 provide good coverage of the lithosphere and mantle under the Australian continent, Coral Sea and Tasman Sea. The variation in structure in the upper part of the mantle is characterized by deter-mining a suite of 1-D structures from stacked record sections utilizing clear P and S arrivals, prepared for all propagation paths lying within a 10° azimuth band. The azimuth of these bands is rotated by 20° steps with four parallel corridors for each azimuth. This gives 26 separate azimuthal corridors for which 15 independent 1-D seismic velocity structures have been derived, which show significant variation in P and S structure. The set of 1-D structures is combined to produce a 3-D representation by projecting the velocity values along the ray path using a turning point approximation and stacking into 3-D cells (5° by 50 km in depth). Even though this procedure will tend to underestimate wave-speed perturbations, S -velocity deviations from the ak135 reference model exceed 6 per cent in the lithosphere. In the uppermost mantle the results display complex features and very high S -wave speeds beneath the Precambrian shields with a significant low-velocity zone beneath. High velocities are also found towards the base of the transition zone, with highS -wave speeds beneath the continent and high P -wave speeds beneath the ocean. The wave-speed patterns agree well with independent surface wave studies and delay time tomography studies in the zones of common coverage. [source] Distortions of EM transients in coincident loops at short time-delaysGEOPHYSICAL PROSPECTING, Issue 6 2000F. Kamenetsky Transient electromagnetic measurements with short time-delays of transients are used for solving different problems within the upper part of a geoelectric section. However, it is necessary to take into consideration distortions connected with self-transients within the transmitter,receiver system. From the practical point of view, it is important to estimate the minimum time-delay after which these distortions may be neglected. We present such an estimation which uses a simple approximation method for a single-loop (or coincident-loop) configuration. For common values of the loop size (10 m × 10 m to 40 m × 40 m) and of the resistivity of a homogeneous half-space (1,100 ,m), the minimum time-delay beyond which we can use a standard interpretation is in the range of 2,10 µs. This is equivalent to a minimum depth of investigation in the range of 1,30 m. [source] Gender Wage Differences in West Germany: A Cohort AnalysisGERMAN ECONOMIC REVIEW, Issue 4 2002Bernd Fitzenberger A comprehensive descriptive analysis of gender wage differences over a long time period does not exist for West Germany. Using an empirical approach which explicitly takes into account changes of wage distributions for both males and females as well as life,cycle and birth cohort effects, we go beyond conventional decomposition techniques of the average gender wage gap. The paper provides stylized facts of the level and dynamics of the gender wage gap from 1975,95. The empirical analysis is based upon the IAB employment subsample. Our findings confirm the importance of distributional effects relating to skill level and employment status. While life,cycle wage growth is in general much lower for females compared to males, comparing their estimated time trends implies that the gender wage gap has narrowed substantially in the lower part of the wage distribution especially for low, and medium,skilled females but much less so in the upper part of the wage distribution. Surprisingly, we do not find any cohort effects for wages of female employees. [source] Volume of a liquid drop detaching from a sphereHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2010Kenji Katoh Abstract A theoretical and experimental study is conducted to investigate the detached volume from a pendant drop on the surface of a sphere. Observation of drop detachment by high-speed video camera reveals that the movement of the upper part of the neck of the drop is quite slow compared to that of the detaching lower part. The surface profile of the upper part was calculated approximately as a static problem using the axisymmetric Laplace equation. Using the drop profile, the system energy, including the work done by the solid,liquid wetting behavior, was calculated. Based on the condition of minimum energy, the volume of the detached part V was calculated. The volume V increases with the sphere diameter and approaches the value for the pendant drop attached to a plate. In addition, V is strongly dependent on the wettability between the sphere and the liquid and decreases with the receding contact angle. The detached volume of the water drop was measured for spheres of porous brick of various diameters. The experimental and theoretical results were found to be in good agreement. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/htj.20305 [source] | |||||||||||||||||||||||||||||||||||||||||||||||||