bluuebunny/crossref_metadata_2025 huggingface dataset:
The 58-Kilodalton Major Virulence Factor of
Francisella tularensis
Is Required for Efficient Utilization of Iron
Authors: Lindgren Helena , Honn Marie , Golovlev Igor , Kadzhaev Konstantin , Conlan Wayne , Sjöstedt Anders
Published: August 2009

We investigated the role of the 58-kDa FTT0918 protein in the iron metabolism of
Francisella tularensis
. The phenotypes of SCHU S4, a prototypic strain of
F. tularensis
subsp.
tularensis
, and the ΔFTT0918 and Δ
fslA
isogenic mutants were analyzed. The gene product missing in the Δ
fslA
mutant is responsible for synthesis of a siderophore. When grown in broth with various iron concentrations, the two deletion mutants generally reached lower maximal densities than SCHU S4. The ΔFTT0918 mutant, but not the Δ
fslA
mutant, upregulated the genes of the
F. tularensis
siderophore locus (
fsl
) operon even at high iron concentrations. A chrome azurol sulfonate plate assay confirmed siderophore production by all strains except the Δ
fslA
strain. In a cross-feeding experiment using medium devoid of free iron, SCHU S4 promoted growth of the Δ
fslA
strain but not of the ΔFTT0918 strain. The sensitivity of SCHU S4 and the ΔFTT0918 and Δ
fslA
strains to streptonigrin demonstrated that the ΔFTT0918 strain contained a smaller free intracellular iron pool and that the Δ
fslA
strain contained a larger one than SCHU S4. In contrast to the marked attenuation of the ΔFTT0918 strain, the Δ
fslA
strain was as virulent as SCHU S4 in a mouse model. Altogether, the data demonstrate that the FTT0918 protein is required for
F. tularensis
to utilize iron bound to siderophores and that it likely has a role also in siderophore-independent iron acquisition. We suggest that the FTT0918 protein be designated Fe utilization protein A, FupA.
The Global Regulator CodY Regulates Toxin Gene Expression inBacillus anthracisand Is Required for Full Virulence
Authors: van Schaik Willem , Château Alice , Dillies Marie-Agnès , Coppée Jean-Yves , Sonenshein Abraham L. , Fouet Agnès
Published: August 2009

In gram-positive bacteria, CodY is an important regulator of genes whose expression changes upon nutrient limitation and acts as a repressor of virulence gene expression in some pathogenic species. Here, we report the role of CodY inBacillus anthracis, the etiologic agent of anthrax. Disruption ofcodYcompletely abolished virulence in a toxinogenic, noncapsulated strain, indicating that the activity of CodY is required for full virulence ofB. anthracis. Global transcriptome analysis of acodYmutant and the parental strain revealed extensive differences. These differences could reflect direct control for some genes, as suggested by the presence of CodY binding sequences in their promoter regions, or indirect effects via the CodY-dependent control of other regulatory proteins or metabolic rearrangements in thecodYmutant strain. The differences included reduced expression of the anthrax toxin genes in the mutant strain, which was confirmed bylacZreporter fusions and immunoblotting. The accumulation of the global virulence regulator AtxA protein was strongly reduced in the mutant strain. However, in agreement with the microarray data, expression ofatxA, as measured using anatxA-lacZtranscriptional fusion and by assayingatxAmRNA, was not significantly affected in thecodYmutant. AnatxA-lacZtranslational fusion was also unaffected. Overexpression ofatxArestored toxin component synthesis in thecodYmutant strain. These results suggest that CodY controls toxin gene expression by regulating AtxA accumulation posttranslationally.
Long-term proton pump induced hypergastrinaemia does induce lineage-specific restitution but not clonal expansion in benign Barrett's oesophagus in vivo
Authors: Obszynska Jolanta A , Atherfold Paul A , Nanji Manoj , Glancy Deborah , Santander Sonia , Graham Trevor A , Otto William R , West Kevin , Harrison Rebecca F , Jankowski Janusz AZ
Published: August 2009

Background

Barrett's oesophagus is a common premalignant lesion caused partly by acid reflux. Although the requisite therapy, proton pump inhibitors (PPIs), have been implicated in the progression of Barrett's oesophagus in animal models, harmful effects of prolonged PPI therapy in Barrett's oesophagus is both inconclusive and controversial. We therefore aimed to test the role of PPI-induced hypergastrinaemia in vitro and see whether any biological parameters were useful surrogates of long-term therapy in man.

Methods

We undertook detailed serological and tissue assessment of gastrin and CCK2 receptors in 90 patients randomised to different doses of PPI therapy during a detailed 2-year follow-up. We also undertook a comprehensive study of cell models to study the consequential biological effects of gastrin on the mucosa.

Results

Gastrin and its cognate receptor CCK2R were expressed highest in the stomach, then less in Barrett's oesophagus and least in squamous oesophagus (SqE) (n=20 paired t-test, p<0.01). Analysis of the change in Barrett's oesophagus segment length change in 70 patients who were randomised to high or low PPI dose showed no difference over 2 years (n=70 t-test, p=0.8). Prolonged PPI use did, however, increase the serum gastrin, (36 pg/ml±57 pg/ml to 103 pg/ml±94 pg/ml (paired t test, p<0.05)). In vitro gastrin also induced changes in OE33(E)cckr Barrett's oesophagus cells, but not OE21(E)cckr squamous cells, transfected with CCK2R; migration was induced by 1 ng/ml of gastrin but proliferation only increased with 100 ng/ml (paired t-test, p<0.01) and both were abolished by antagonists.

Conclusion

While the short-term effects of gastrin enhance epithelial restitution in Barrett's oesophagus (but not squamous mucosa) there is no clinical evidence that Barrett's oesophagus length expands over time. This study, which is the largest and longest term randomised controlled trial of gastrin biology in Barrett's oesophagus, is further proof of the clinical safety of PPI therapy.
Seismic studies of the crust under the Williston Basin
Authors: Kanasewich E. R. , Hajnal Z. , Green A. G. , Cumming G. L. , Mereu R. F. , Clowes R. M. , Morel-a-l'Huissier P. , Chiu S. , Macrides C. G. , Shahriar M. , Congram A. M.
Published: August 2009

The seismic refraction method was used in 1981 to study the crust under the northern half of the Williston Basin, in Saskatchewan. A new method of spatial seismic recording, based on a triangular arrangement of receivers, was used for the first time to obtain three-dimensional structure and velocity information. The broadside seismic refraction and wide-angle reflection data obtained by the technique were of particular value in defining several faulted blocks. These blocks are also characterized by aeromagnetic anomalies trending in a northerly direction. The crustal thickness in the southern part of the western provinces shows large variation ranging from 35 to 50 km. Much of the area is also notable for the presence of one or more low-velocity layers and a high-velocity lower crust. There is good evidence for significant lateral heterogeneity, and detailed deep seismic reflection and refraction studies would likely yield information on dips and strikes of beds and faults around the basin as well as define the properties of the various terranes of the Hudsonian mobile belt.
Clay mineral indicators of geological and geochemical subaerial modification of near-surface Tertiary sediments on the northeastern Grand Banks of Newfoundland
Authors: Segall M. P. , Buckley D. E. , Lewis C. F. M.
Published: August 2009

Based on mineralogical studies of clay-sized material, two sedimentary environments have been interpreted for the Tertiary sediments on northeastern Grand Banks of Newfoundland: (i) an acidic leaching environment (pH < 7.0) is observed as a weathered, probably desiccated crust directly underlying the Tertiary–Quaternary unconformity; and (ii) an alkaline marine environment directly underlies the weathered zone. The weathered zone has been sampled at depths of 2–3 m (locally) below the seabed surface in the study area. Mineralogically the < 2 μm size fraction is characterized by relatively high kaolinite concentrations (7 – 18%) and a clinochlore component. The more deeply buried sediments have been deposited under marginal to normal marine conditions (a regressive phase, pH 7–8). Clay-sized components in this zone are characterized by high concentrations of expandable minerals (average 45%) and chamosite.Sediments from both of these environments differ from the thin, clay-poor Late Pleistocene – Holocene sands and gravels at the present seabed surface. Late Pleistocene – Holocene sediments have clay-sized mineralogical suites, partially reworked from weathered zone components (up to 15% kaolinite, locally) but are mostly derived from a northern latitude provenance (high illite (average 28%), quartz (average 14%), and feldspar (average 19%)). Expandable mineral phases range from 0 to 24%.The differing clay-sized mineralogical signatures indicate (i) alteration of the Tertiary marine sediments (expandable minerals) by acidic leaching to form a kaolinite-enriched weathered zone; (ii) the reworking of weathered zone materials during deglacial marine transgressions; (iii) the incorporation of sediments from the weathered zone into the Holocene sedimentary regime during Recent times, possibly by ice scouring; (iv) input from northern latitude provenances by reworking of earlier deposited glacial material; and (v) minor clay input to the Late Pleistocene – Holocene sands and gravels from ice rafting over the past 10 000 years.
Shallow sediment temperature perturbations and sediment thermal conductivities, Canadian Beaufort Shelf
Authors: Taylor Alan E. , Allen Vic
Published: August 2009

A regional survey of sediment temperatures and thermal conductivities was conducted at 33 stations across the outer shelf of the Canadian Beaufort Sea. Techniques developed for deep-ocean heat-flow investigations were used to study the upper 3 m of sediments. Temperature–depth profiles exhibit curvatures that may be explained by seasonal changes in bottom-water temperature; some curvatures may arise from other causes. It is unlikely that thermal effects of the underlying, degradational permafrost can be detected from such shallow temperatures because of the magnitude of, and lack of independent knowledge of, these transient and local influences. Thermal conductivities measured on sediment cores and corrected to −1 °C range from 0.9 to 2.4 W m−1 K−1 (average 1.26 ± 0.2 W m−1 K−1). These values are higher than typical conductivities of deep-ocean sediments. The wide range of thermal conductivities observed across the outer Beaufort Shelf may be explained by the presence of a varying fraction of quartz sand that represents a component of high conductivity.
Stratigraphy and genesis of five superposed paleosols in pre-Wisconsinan drift on Mokowan Butte, southwestern Alberta
Authors: Karlstrom Eric T.
Published: August 2009

Five paleosols in five superposed diamicts (probably tills) on Mokowan Butte permit subdivision of pre-Wisconsinan drift and a description of Quaternary and probably late Tertiary soil-forming environments. The surface soil and upper two buried paleosols (soils 5, 4, and 3, respectively) have strongly developed, 1–5 m thick, leached, reddish, clay-rich (20–48% clay), argillic horizons overlying indurated petrocalcic, calcic, or leached B horizons. The lower two buried paleosols (soils 2 and 1) are strongly developed and have 40–150 cm thick, clay-rich (18–49% clay) argillic horizons over calcic, petrocalcic, or leached B horizons. Based on their resemblance to Paleudalfs, Paleustalfs, or Palexerults, soils 5, 4, and 3 probably formed under interglacial climates that were moister and at least 6 °C warmer than the present. Properties of soil 2 (Petrocalcic Paleustalf) and soil 1 (Typic Croboralf) imply soil formation under warm, semi-arid climates and a modern type of climate, respectively. Estimates of soil age based on degree of soil formation, paleomagnetic data, and regional correlation with dated glacial chronologies suggest soils 5 and 4 are in middle and early Pleistocene tills (= early Illinoian or Kansan and Nebraskan?), respectively, and soils 3, 2, and 1 are in late Pliocene till or diamict.
Foraminiferal zonation of the Viking interval in the Hasler Shale (Albian), northeastern British Columbia
Authors: Stelck C. R. , Koke Kory R.
Published: August 2009

A dominantly arenaceous foraminiferal fauna of over 33 genera and 65 species was recovered from silty shales in the mid-portion of the Hasler Formation in the upper Albian part of the Fort St. John Group. The assemblages lie stratigraphically below occurrences of Neogastroplites and below the Miliammina manitobensis Zone. The foraminifera come from above the occurrence of Haplophragmoides gigas gigas, although assignment of the beds is to the upper part of the H. gigas Zone.The upper part of the Haplophragmoides gigas Zone may be divided into several subzones above the H. gigas gigas Sub-zone in ascending order, viz., H. gigas ssp A Subzone, Reophax tundraensis Subzone, Trochammina depressa Subzone, Trochammina umiatensis Subzone, and Reophax troyeri Subzone.The assemblages have close affinities with the faunas of both the overlying and underlying shales, and are an expression of a late shallowing–deepening cycle within the Skull Creek – Joli Fou seaway. They were penecontemporaneous with Viking Sandstone deposition in Alberta. The assemblages are interpreted as mid-neritic to shallow neritic from slightly acidic waters. Only 4 of 150 samples collected carried calcareous components. Diagnostic megafauna are lacking.The microfaunas include the following genera: Bathysiphon, Hyperammina, Kechenotiske, Thuramminoides, Psammosphaera, Saccammina, Reophax, Scherochorella, Hippocrepina, Glomospira, Glomospirella, Ammodiscus, Miliammina, Psamminopelta, Haplophragmoides, Trochamminoides, Ammomarginulina, Ammobaculites, Haplophragmium, Ammobaculoides, Trochammina, Textulariopsis, Pseudobolivina, Verneuilinoides, Verneuilina, Uvigerinammina, Gaudryina, Gravellina, Eggerella, Lenticulina, Marginulina, Lagena, Nodosaria.
The alteration of sparry calcite crystals in a vadose setting, Grand Cayman Island
Authors: Jones Brian
Published: August 2009

Calcite crystals that cement the dolostone clasts in a karst breccia from Grand Cayman Island have been substantially altered as a result of infestation by algae and (or) fungi as well as etching that may or may not be related to organic activity. The features produced include (1) borings, (2) constructive micrite envelopes, (3) spiky calcite, (4) almond-shaped etch pits, (5) crystal surfaces with a blocky topography and (6) etched crystal surfaces that suggest some of the crystals may have grown by spiral growth. Spar calcite crystals in a vadose setting can be.subjected to complex chemical and physical processes that are commonly mediated by algae and (or) fungi. These microorganisms are capable of removing CaCO3 from substrates via dissolution, transporting that CaCO3 elsewhere and then directly or indirectly causing its reprecipitation during the calcification of their filaments and (or) the formation of the constructive micrite envelopes.The extensive alteration of calcite cements in the karst breccia from Grand Cayman Island demonstrates that organically mediated processes can be extremely important in vadose diagenesis. Recognition of the features produced by these complex processes may prove useful in the identification of carbonates that have been subjected to vadose diagenesis.
Pressure and temperature conditions of metamorphism in the vicinity of three massive sulfide deposits, Flin Flon – Snow Lake belt, Manitoba
Authors: Aggarwal Pradeep K. , Nesbitt Bruce E.
Published: August 2009

Estimates of pressure and temperature conditions of metamorphism in the vicinity of three massive sulfide deposits of the Flin Flon – Snow Lake, Manitoba, greenstone belt have been obtained using mineral assemblages in mafic and felsic metavolcanic rocks. The Flin Flon area around the Centennial deposit, in the western part of the belt, has been metamorphosed to low greenschist facies. Near the Spruce Point deposit, in the central part of the belt, the metamorphic conditions are estimated to be of the upper greenschist facies, with a temperature of 475 ± 75 °C at 2.6 ± 1.2 kbar pressure (1 kbar = 0.1 kPa). The Snow Lake area to the west, in the vicinity of the Anderson Lake deposit, has been metamorphosed to sillimanite grade. In the staurolite–biotite–sillimanite zone, the temperature and pressure conditions were 580 ± 25 °C and 5.25 + 0.75 kbar; in the biotite–sillimanite–almandine zone, the temperature was 620 ± 25 °C at a maximum pressure of 6.2 kbar. Based on the temperature and pressure estimates from the Snow Lake area, it is suggested that experimental studies of the upper stability of staurolite and quartz at low pressure indicate temperatures that are unusually high compared with those indicated by field assemblages.
New polygnathid conodonts from the Frasnian (Upper Devonian) of southeastern Alaska
Authors: Savage Norman M.
Published: August 2009

Of several Late Devonian conodont apparatuses being studied as part of ongoing investigations in southeastern Alaska, two are sufficiently distinct to warrant description at this time. Although the reconstruction of conodont apparatuses in large assemblages frequently presents workers with more than one solution, sometimes a combination of elements in low-diversity collections occurs often enough to leave less doubt that they belong to a single species. This is the case for the two taxa described here. Representative individuals of Polygnathus sinuosus wadleighensis n. ssp. are characterized by an anguliplanate Pa element and by ramiform elements that bear long, well-spaced denticles. Representative individuals of Polygnathus buddingtoni n. sp. have a Pa element resembling that of Polygnathus webbi in several features but with a shorter carina; the ramiform elements are robust and bear discrete, stout denticles. These Alaskan occurrences are of middle Frasnian age.
Yochelcionella americana (Mollusca) from the Lower Cambrian of Newfoundland
Authors: Peel John S.
Published: August 2009

Yochelcionella americana Runnegar and Pojeta, 1980, is described from the Forteau Formation (upper Lower Cambrian) of western Newfoundland. This is only the second occurrence of this distinctive species, originally described from Pennsylvania, and the first certain record of the genus from Canada.
Lacustrine ostracodes in the Late Pleistocene Sunnybrook diamicton of southern Ontario, Canada
Authors: Westgate J. A. , Chen F.-J. , Delorme L. D.
Published: August 2009

Two opposing interpretations have been made on the depositional origin of the Late Pleistocene Sunnybrook diamicton in the Metro-Toronto region of southern Ontario. The traditional view holds this deposit to be a till, but more recent arguments advocate a glaciolacustrine origin by suspension deposition and ice rafting.The discovery of a low-diversity ostracode fauna consisting of Candona subtriangulata, Candona caudata, and Darwinula stevensoni in the Sunnybrook diamicton suggests a lacustrine origin. Excellent preservation of thin, fragile shells and a mixture of juveniles and adults in sediments of varying texture—clayey silt to silty clay—indicate that there has been little winnowing or selective sorting and that the ostracodes are in situ. Indications are that the Sunnybrook diamicton was deposited in a large, deep, and cold lake.These new palaeontological observations call for a reassessment of the Quaternary stratigraphy of the Ontario Basin and suggest that the Laurentide Ice Sheet in the eastern Great Lakes region was less extensive during the early part of the Wisconsin Glaciation than previously assumed.
A magnetotelluric investigation under the Williston Basin of southeastern Saskatchewan
Authors: Maidens J. M. , Paulson K. V.
Published: August 2009

A magnetotelluric (MT) survey using naturally occurring ultra low frequency (ULF) and extremely low frequency (ELF) sources was conducted in the frequency range of 0.5 mHz to 20 Hz in order to locate the western edge and the depth of the North American Central Plains (NACP) conductivity anomaly in the Bengough area of southeastern Saskatchewan. The data base was also used to evaluate the complex singular-value decomposition (CSVD) method of MT processing and to corroborate certain geologic interpretations in this part of the Williston Basin.Modelling of the resulting impedance tensors revealed a deep (10–15 km) zone with resistivity (35–85 Ω∙m) significantly lower than typical values (1000–1500 Ω∙m) obtained from a borehole resistivity log of the top 30 m of the Precambrian at a depth of 2.3 km. An increase in depth (to 20 km) and resistivity (150–275 Ω∙m) of this deep zone measured at the survey's west end was interpreted as indicating the anomaly's western edge. The CSVD processing of the data did not show any particular advantages over the conventional cross-spectral method.
Late Quaternary vegetational history of the Black River region in northeastern Alaska
Authors: Anderson Patricia M. , Reanier Richard E. , Brubaker Linda B.
Published: August 2009

Two pollen diagrams describe the previously unknown vegetational history of the Black River and Little Black River drain ages of northeastern Alaska. Tundra grew throughout much of the region between ca. 19 800 and 15 000 years BP. Prior to 18 000 years BP, the vegetation was dominated perhaps by xeric Cyperaceae communities, but apparently between ca. 18 000 and 15 000 years BP a more diverse herb tundra characterized the vegetation. Herbaceous species continued to be important in the vegetation until ca. 9700 years BP, although Betula nana–glandulosa and Salix species became more common after 15 000 years BP. At ca. 9700 years BP a major change in the vegetation occurred with the spread of Populus (probably P. balsamifera), B. nana–glandulosa, and Salix, possibly resulting in a mosaic of shrub tundra and Populus gallery forest. Picea glauca migrated into the Black River region ca. 7500 years BP, followed by Alnus ca. 7200 years BP and Picea mariana ca. 6000 years BP.Herb zone records from the Black River region support the hypothesis that eastern Beringian vegetation was characterized by a tundra mosaic prior to 14 000 years BP. Chronological and geographical patterns in the Populus subzone from eastern Beringia suggest that the expansion of Populus populations may not have been exclusively in response to climate change. Dates of Picea arrival on the western Porcupine Plateau indicate that this area probably was not an early Holocene migration route for Picea.
Airborne UHF radar sounding of glaciers and ice shelves, northern Ellesmere Island, Arctic Canada
Authors: Narod B. Barry , Clarke Garry K. C. , Prager Bradley T.
Published: August 2009

More than 2000 line-kilometres of ice were sounded in 1981 using an 840 MHz pulsed radar system. The surveyed regions include Mt. Oxford ice cap, Disraeli Glacier, Milne Glacier, Ward Hunt Ice Shelf, and Milne Ice Shelf in northern Ellesmere Island, Arctic Canada. The maximum ice thickness that was reliably recorded was 750 m for Milne Glacier. In addition to ice thickness interpretation, the power reflection coefficient (PRC) and propagation loss rate were estimated from the data. Measured basal PRC's differ for ice shelves, floating glaciers, and grounded glaciers. Spatial variations of PRC have been used to infer a composite structure for the ice shelves. Ward Hunt Ice Shelf proved difficult to sound, probably because of its known saline and brackish chemistry. Excellent results were obtained for Milne Ice Shelf and its depth was found to average roughly 70 m, in places attaining 100 m. Bottom-side crevasses were observed within Milne Ice Shelf. The characteristic ridge and trough topography of the ice shelf surface has little or no bottom-side expression.
Ferromanganese deposits from the Gulf of Alaska Seamount Province: mineralogy, chemistry, and origin
Authors: Koski Randolph A.
Published: August 2009

Ferromanganese-oxide deposits dredged from four seamounts (Welker, Miller, Murray, and Patton) in the Gulf of Alaska Seamount Province include poorly crystallized microlaminated crusts on basalt substrate, well-crystallized Mn-oxide veins in epiclastic sedimentary rocks, and crystalline Mn-oxide layers and micronodules in phosphorite. The principal rock types dredged are alkali-basalt pillow fragments and tuffaceous conglomerate and sandstone. The glassy rims of pillow fragments, the glassy goundmass of large volcanic clasts, and the tuffaceous component of the sediment are altered to palagonite. Other low-temperature alteration products include phillipsite, smectite, and carbonate-apatite.Thick (10–50 mm) Fe–Mn crusts consist mainly of δ-MnO2; straight and cuspate growth laminae indicate variable growth rates and periods of nondeposition. A larger number of detrital particles toward the top of thick crusts record the increasing influence of active volcanoes of the Aleutian arc during northwestward movement of the Pacific plate. Thick crusts on basalt substrate have higher Mn/Fe ratios and lower Co content than Fe–Mn crusts from low-latitude seamounts of the central Pacific region. Thin (< 10 mm) crusts on volcaniclastic substrate contain todorokite and birnessite and have higher Mn/Fe ratios, Ni, and Cu and lower Fe and Co than thick Gulf of Alaska crusts.Veins of todorokite and cryptomelane with complex internal structure occur in altered tuffaceous sandstone and conglomerate from Miller Seamount. Fibrous todorokite has a composition similar to those of other marine examples but may contain up to 7% Mn2+ in M2 sites. Microprobe analysis of the marine cryptomelane indicates a composition that is approximately (K,Ba)1–2(Mn4+,Co)7–8O16∙x(H2O).A third type of Fe–Mn deposit in phosphorite is an intimate mixture of todorokite (and minor δ-MnO2)-bearing layers and micronodules, carbonate-apatite, and phillipsite that encloses grains of altered volcanic glass and lithic fragments.The microlaminated structure, mineralogy (predominantly δ-MnO2), and composition (Mn/Fe ratio and transition metal, rare earth element, U, and Th contents) of the thick crusts are characteristic of hydrogenetic Fe–Mn crusts elsewhere in the Pacific. Conversely, the crystallinity and chemical composition of the Mn-oxide veins and thin crusts indicate formation during diagenesis of the volcanogenic sediment substrate. Mn and other transition metals are mobilized during low-temperature oxidative alteration (palagonitization) of basaltic volcanic glass; the oxidation of Fe2+ to Fe3+ during palagonitization and the dissolution of the dilute biogenic fraction of the sediment combine to lower the Eh of ambient pore fluid and enhance the mobility of Mn2+. Diagenesis in the phosphatic sandstone from Patton Seamount involves organic-rich sediment and pore waters elevated in phosphorus owing to upwelling above a large volcanic edifice.
The Lake Algonquin shoreline, Kincardine – Port Elgin, Ontario
Authors: Karrow P. F.
Published: August 2009

Elevations at the base of the shore cliff attributed to glacial Lake Algonquin are anomalously low, by ~10–15 m, between Kincardine and Port Elgin, Ontario. Weak remnant bluff-face benches, a hanging terrace of Algonquin age along Underwood Creek, and an incipient gravel foreland all record Main Algonquin water levels through much of this interval. It is suggested that subtill sand and gravel, weakly resistant to wave erosion, allowed the shoreline position to remain nearly constant as water levels fell through the "Upper Group" of Algonquin beaches.
Preconsolidation of tills and intertill clays by glacial loading in southern Saskatchewan, Canada
Authors: Sauer E. Karl , Egeland Anne K. , Christiansen E. A.
Published: August 2009

Preconsolidation of pre-Battleford tills and intertill clays resulted in a narrow range of effective pressures (1800 ± 200 kPa) at 10 sites along a 1300 km transect across southern Saskatchewan. These data suggest an almost invariant loading system that is independent of total ice thickness, which ranged from 1150 to 2000 m. The preconsolidation process apparently took place in a temperate glacier environment. The loading system is characterized as a variable thickness of ice related to distance from the glacier terminus. A steady hydraulic "grade line" sustained a potentiometric surface within the subglacial sediments at an elevation consistently 69–76% of the total ice thickness. This mechanism maintains small fluctuations in effective stress.
The Pipestone Pond Complex, central Newfoundland: complex magmatism in an eastern Dunnage Zone ophiolite
Authors: Jenner G. A. , Swinden H. Scott
Published: August 2009

Ophiolitic rocks are preserved in both the Notre Dame and Exploits subzones in the Dunnage Zone of the Newfoundland Appalachians. Ophiolites in the Exploits Subzone are generally less well preserved and exposed than their Notre Dame Subzone counterparts and, consequently, have received less attention in the literature.The Pipestone Pond Complex is an Exploits Subzone ophiolitic sequence, which outcrops on the western side of a structural window through the Exploits Subzone into the underlying Gander Zone. It includes a basal harzburgite, which passes upwards into a cumulate pyroxenite and gabbro sequence, and thence into isotropic gabbro intruded by pegmatitic gabbro, diabase, and plagiogranite. There is no sheeted dyke unit. Pillow lava occurs at the top of the sequence but is not observed to be in stratigraphic contact with the intrusive rocks. The ophiolitic rocks are structurally disrupted and no single cross section traverses the complete ophiolitic stratigraphy.Although the stratigraphic sequence of the Pipestone Pond Complex is relatively straightforward, whole-rock geochemical and Nd/Sm isotopic data provide evidence for a complex magmatic history. The intrusive rocks have εNd(t) ranging from −1.1 to + 4 and geochemical signatures indicating derivation from depleted and refractory mantle sources that were clearly influenced by subduction. Within the intrusive rocks, there are no simple petrogenetic relationships among the gabbros and dykes and trondhjemites. The extrusive rocks, in contrast, have εNd(t) of + 7.3 and geochemical signatures similar to those of normal mid-ocean-ridge basalts. They represent magmatism derived from depleted oceanic mantle, not affected by the subducted slab.The tectonic interpretation of the Pipestone Pond Complex is hampered by a lack of definitive evidence for the relative age of the arc-related plutonic rocks and the non-arc-related extrusive rocks. Two possible interpretations are (i) the initiation of subduction under oceanic crust and (ii) arc rifting. The Pipestone Pond Complex is geologically and geochemically analogous to the Boil Mountain Complex in Maine, and together they may form part of an extensive ophiolitic terrane that was emplaced upon the Gondwanan continental margin prior to its collision with Laurentia.
Petrochemistry, tectonic history, and Sr–Nd systematics of the Liscomb Complex, Meguma Lithotectonic Zone, Nova Scotia
Authors: Clarke D. B. , Chatterjee A. K. , Giles P. S.
Published: August 2009

The Liscomb Complex (area ca. 240 km2), located in the Meguma Lithotectonic Zone of the Canadian Appalachians, consists of three main lithological components: high-grade gneisses, mafic plutons, and peraluminous granitoid bodies. Field relations and 40Ar/39Ar dating (369–377 Ma) embracing all three lithological groups show that the complex is post-Acadian. The gneisses occur as a domal uplift and represent a mixed volcano-sedimentary package that is structurally, metamorphically, and chemically distinct from the surrounding low-grade metawackes and metapelites of the Meguma Group. The mafic intrusions (quartz gabbro to quartz diorite) have major and trace element compositions (e.g., Ti–Zr–Y, Nb–Zr–Y, Th/Yb – Ta/Yb, rare earth elements) typical of within-plate or volcanic arc materials. The peraluminous granitoid rocks range from two-mica granodiorites to leucomonzogranites, and are mineralogically and chemically very similar to granitic rocks elsewhere in the Meguma Zone. Neodymium and strontium isotopic analyses show that (i) the gneisses have a wide range of εNd and initial Sr isotopic ratios, with Nd model ages that are generally younger than those of the Meguma Group; (ii) the mafic intrusive rocks represent magmas derived from slightly depleted mantle sources (εNd +3.3 to +1.4), in part modified by crustal contamination (εNd +0.5 to −5.0); and (iii) the granitoid rocks isotopically overlap both the South Mountain Batholith and the intermediate gneisses of the Liscomb Complex. The combined field, petrological, and chemical evidence suggests that underplating by mafic magmas, followed by thermal doming of the gneisses, diapirism through the Meguma Group, anatexis, and multiple intrusion of both mafic and felsic magmas best explain the observed relationships in the Liscomb Complex. This mechanical model may also apply to granite generation throughout the Meguma Zone.
Thermal conductivity measurement of rock fragments using a pulsed needle probe
Authors: Lewis T. J. , Villinger H. , Davis E. E.
Published: August 2009

A heat pulse generated inside a needle probe can be used to measure the thermal conductivity of surrounding rock fragments or drill cuttings. As the pulse of heat is conducted outwards into the surrounding aggregate of rock fragments and water, the decrease in temperature inside the probe is recorded as a function of time. An asymptotic relation between probe temperature, conductivity, and inverse time since the heat pulse is shown to be accurate for the range of times used. The relatively slow thermal response of the probe in samples with higher conductivities is accommodated by a delay in the origin time of the pulse. The combined correction for finite pulse length and slow probe response is shown to be small and predictable. The thermal conductivity of rock fragments is calculated from a model that is dependent on the water content of the sample, as in other methods. Results using this method and a divided bar apparatus are equivalent, given the expected accuracy of a divided bar. The measured thermal conductivities of water, fused quartz, and crystalline quartz compare closely with their accepted values.
Age, distribution, and stratigraphy of Glacier Peak tephra in eastern Washington and western Montana, United States
Authors: Foit Jr. Franklin F. , Mehringer Jr. Peter J. , Sheppard John C.
Published: August 2009

Tephra layers from Williams Lake Fen, Wildcat Lake, and East Wenatchee, Washington, and Kearns Basin, Lost Trail Pass, Sheep Mountain Bog, and Marys Frog Pond, Montana, were analyzed by electron microprobe (EMP), and associated lake deposits were radiocarbon dated. Though the tephra layers can be grouped by source (Glacier Peak, Mount Mazama, Mount Saint Helens, and unknown source), statistical analyses of both glass and mineral compositions show that finer distinctions within a group (for example, Glacier Peak B, M, and G) cannot be made on the basis of chemical data obtained using conventional EMP techniques. It appears that more-sensitive analytical techniques may be needed to discriminate among the Glacier Peak tephras. Tephra stratigraphy at the various sites reveals a potentially greater complexity in Glacier Peak tephra distributions and ages than was anticipated. All sites, except Sheep Mountain Bog and East Wenatchee, contained two Glacier Peak tephras. Taken as a whole the Glacier Peak tephra layers may record closely timed, multiple eruptions with restricted ash falls as well as widespread tephra from large eruptions. Radiocarbon dating generally confirms a 14C age of 11 200 years BP for a distal Glacier Peak couplet(s) that occurs, stratigraphically, both above and below Mount Saint Helens J tephra in east-central Washington.
Tectonic development of the northern Williston basin: a seismic interpretation of an east – West regional profile
Authors: Zhu Chengnan , Hajnal Zoltan
Published: August 2009

Based on seismic analysis in conjunction with well control, 10 time-stratigraphic sequences and sub-sequences are mapped in Phanerozoic strata of the northern Williston basin. Seven additional time-unit subdivisions are distinguished in the upper-most Cretaceous. These sequences, sub-sequences, and units, and their unconformities, reveal that the northern Williston basin experienced three developmental episodes: initial subsidence during the time of deposition of the Sauk sequence (540–505 Ma); stability during the time of deposition of the Tippecanoe to Upper Colorado sequences (480–84 Ma); and deformation since the time of deposition of the Montana sequence (post-66 Ma). The seismic unconformities indicate nine subsidence events separated by five major erosional periods. All the major erosional cycles are consequences of periodic and incongruent uplift and tilting of the western and eastern flanks of the basin relative to its centre.
J-Orchestra
Authors: Tilevich Eli , Smaragdakis Yannis
Published: August 2009

J-Orchestra is a system that enhances centralized Java programs with distribution capabilities. Operating at the bytecode level, J-Orchestra transforms a centralized Java program (i.e., running on a single Java Virtual Machine (JVM)) into a distributed one (i.e., running across multiple JVMs). This transformation effectively separates distribution concerns from the core functionality of a program. J-Orchestra follows a semiautomatic transformation process. Through a GUI, the user selects program elements (at class granularity) and assigns them to network locations. Based on the user's input, the J-Orchestra backend
automatically partitions
the program through compiler-level techniques, without changes to the JVM or to the Java Runtime Environment (JRE) classes. By means of bytecode engineering and code generation, J-Orchestra substitutes method calls with remote method calls, direct object references with proxy references, etc. It also translates Java language features (e.g., static methods and fields, inheritance, inner classes, new object construction, etc.) for efficient distributed execution.

We detail the main technical issues that J-Orchestra addresses, including its mechanism for program transformation in the presence of unmodifiable code (e.g., in JRE classes) and the translation of concurrency and synchronization constructs to work correctly over the network. We further discuss a case study of transforming a large, commercial, third-party application for efficient execution in a client server environment and outline the architectural characteristics of centralized programs that are amenable to automated distribution with J-Orchestra.
The reported and revealed importance of job attributes to aspiring information technology
Authors: Kuhn Kristine , Joshi K. D.
Published: August 2009

Although information systems practitioners recognize the importance of diversity in recruiting efforts and offer advice on targeted recruiting, IT researchers have not provided empirical research findings to support these efforts. In the absence of research demonstrating group-level differences in what employees want from their work, any attempt at targeted recruitment strategies is at best based on anecdotal evidence and at worst on mistaken premises and potentially invalid stereotypes. In this study, we examine gender similarities and differences in job attribute preferences among prospective IT professionals. Participants evaluated a series of multi-attribute job descriptions in a policy-capturing design. Although male and female aspiring IT professionals gave the same average importance ratings to work values and desired the same types of job attributes, there were some subtle gender differences in the weights they place on these factors in evaluating potential jobs. In some cases, observed results were contrary to gender differences reported in research suggesting that commonly accepted stereotypes do not necessarily apply. For instance, men were actually somewhat more averse to lengthy work weeks than women, and women did not place any less weight on income than men.
Trust in virtual teams
Authors: Mitchell Alanah , Zigurs Ilze
Published: August 2009

Trust was one of the most prominent topics of early research in virtual teams, highlighted by the emergence of the theory of swift trust. As researchers continue to study this topic, it is important to understand what problems have been solved as well as what aspects of trust in virtual teams remain a mystery. We address this goal by presenting an in-depth analysis of existing research on trust in virtual teams. We review theories, methods, tasks, technologies, and major outcome themes from 42 empirical studies over an eleven-year period from 1997 through 2007. The analysis reveals gaps and areas for future research, including the need for additional theorizing, broader use of methods, deliberate interventions that enhance trust, and continuing evolution of the trust concept.
Taking the high road to web services implementation
Authors: Fink Lior , Neumann Seev
Published: August 2009

The increasing adoption of Web services is one of the most important technological trends in contemporary business organizations. This trend is motivated by claims about the ability of Web services to facilitate information technology (IT) flexibility, improve information management, and even lead to a competitive advantage. However, as the move towards Web services is gaining momentum, research about their organizational consequences remains mostly conceptual. This exploratory study empirically investigates whether the implementation of Web services applications is associated with these technological, informational, and strategic impacts. A field study approach is employed to collect cross-sectional data from 293 IT managers in Israel. Data analysis generally supports the research hypotheses, showing that the implementation of Web services applications positively affects the flexibility of IT infrastructure resources and information flexibility. The results also show that a specific implementation -- an Enterprise Information Portal -- also has positive effects on the flexibility of IT infrastructure capabilities, information quality, and IT-based competitive advantage. Finally, the results demonstrate the magnitude of the organizational impacts of Web services applications by comparing them to those of non-Web ERP systems. The implications of the findings for practice and research are discussed
Dynamics of Winds and Currents Coupled to Surface Waves
Authors: Sullivan Peter P. , McWilliams James C.
Published: August 2009

We discuss the coupling processes between surface gravity waves and adjacent winds and currents in turbulent boundary layers. These processes mediate exchanges of momentum, heat, and gases between the atmosphere and ocean and thus are of global significance for climate. Surface waves grow primarily by pressure-form stress from airflow over the waveforms, and they dissipate in the open sea by wave breaking that injects and stirs momentum, energy, and bubbles into the ocean. Wave motions pump wind eddies that control fluxes across the lower atmosphere. Flow separation occurs behind steep wave crests, and at high winds the crests flatten into spume, which diminishes the drag coefficient. In the ocean the Lagrangian-mean wave velocity, Stokes drift, induces a vortex force and material transport. These generate Langmuir circulations penetrating throughout the boundary layer and enhancing entrainment at the stratified interior interface in combination with other turbulent eddies and inertial-shear instability.
Local complement activation triggers neutrophil recruitment to the site of thrombus formation in acute myocardial infarction
Authors: Distelmaier Klaus , Adlbrecht Christopher , Jakowitsch Johannes , Winkler Susanne , Dunkler Daniela , Gerner Christopher , Wagner Oswald , Lang Irene M. , Kubicek Markus
Published: August 2009

Atherosclerotic plaque rupture with subsequent mural thrombus formation is considered the main event compromising epicardial flow in acute myocardial infarction (AMI). However, the precise mechanisms underlying acute coronary occlusion are unknown.

We compared the proteomic profiles of systemic plasma and plasma derived from the site of thrombus formation of patients with AMI by two-dimensional gel electrophoresis and ELISA. We identified a local activation of the complement system, with selective accumulation of the complement activator Creactive protein (CRP) and the downstream complement effectors C3a and C5a. CRP in coronary thrombus co-localised with C1q and C3 immunoreactivities, suggesting classical complement activation. In vitro, coronary thrombus derived plasma enhanced neutrophil chemotaxis in a C5a dependent fashion. In vivo, neutrophil accumulation at the site of thrombus formation paralleled the time delay from symptom onset to first balloon inflation or aspiration, and was correlated with C5a and enzymatic infarct size. We present the first direct evidence for localised complement activation in acute coronary thrombi. Our data indicate that local complement effectors amplify the vascular occlusion process in AMI by enhanced neutrophil recruitment.
Red cell distribution width (RDW) as a predictor of long-term mortality in patients undergoing percutaneous coronary intervention
Authors: Poludasu Shyam , Marmur Jonathan D. , Weedon Jeremy , Khan Waqas , Cavusoglu Erdal
Published: August 2009

Red cell distribution width (RDW) has been shown to be an independent predictor of mortality in patients with coronary artery disease and in patients with heart failure. The current study evaluated the prognostic utility of RDW in patients undergoing percutaneous coronary intervention (PCI). We evaluated 859 patients who underwent PCI during January 2003 to August 2005. After a median follow up of four (interquartile range 3.1 to 4.4) years, there were a total of 95 (11%) deaths. RDW was analysed as a categorical variable with empirically determined cut points of 13.3 and 15.7 (low RDW <13.3, medium RDW ≥13.3 to <15.7, high RDW ≥15.7) based on differences in hazard ratio (HR) for death among RDW deciles.In univariate analysis, higher RDW was a significant predictor of mortality (p<0.001). In multivariate analysis there was a significant two-way interaction between RDW and haemoglobin (Hgb). RDW was not an independent predictor of mortality in patients with Hgb <10.4. However, among patients with Hgb >10.4, high RDW was a strong and independent predictor of mortality. For patients with Hgb ≥10.4 to <12.7, HR for death in patients with high RDW relative to low RDW was 5.2 (95% confidence intervals [CI]: 2.0–13.3). For patients with Hgb ≥12.7, HR for death in patients with high RDW relative to low RDW was 8.6 (CI:2.8–28.6). Higher RDW was a strong and independent predictor of long-term mortality in patients undergoing PCI who were not anaemic at baseline.