bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crustal velocity structure of the southern Nechako basin, British Columbia, from wide-angle seismic traveltime inversion1This article is one of a series of papers published in this Special Issue on the theme of New insights in Cordilleran Intermontane geoscience: reducing exploration risk in the mountain pine beetle-affected area, British Columbia.
Authors: Stephenson A.L. , Spence G.D. , Wang K. , Hole J.A. , Miller K.C. , Clowes R.M. , Harder S.H. , Kaip G.M. 
Published: July 2011

In the BATHOLITHSonland seismic project, a refraction – wide-angle reflection survey was shot in 2009 across the Coast Mountains and Interior Plateau of central British Columbia. Part of the seismic profile crossed the Nechako Basin, a Jurassic–Cretaceous basin with potential for hydrocarbons within sedimentary strata that underlies widespread volcanic rocks. Along this 205 km-long line segment, eight large explosive shots were fired into 980 seismometers. Forward and inverse modelling of the traveltime data were conducted with two independent methods: ray-tracing based modelling of first and secondary arrivals, and a higher resolution wavefront-based first-arrival seismic tomography. Material with velocities less than 5.0 km/s is interpreted as sedimentary rocks of the Nechako Basin, while velocities from 5.0–6.0 km/s may correspond to interlayered sedimentary and volcanic rocks. The greatest thickness of sedimentary rocks in the basin is found in the central 110 km of the profile. Two sub-basins were identified in this region, with widths of 20–50 km and maximum sedimentary depths of 2.5 and 3.3 km. Such features are well-defined in the velocity model, since resolution tests indicate that features with widths greater than ∼13 km are reliable. Beneath the sedimentary rocks, seismic velocities increase more slowly with depth — from 6.0 km/s just below the basin to 6.3 km/s at ∼17 km in depth, and then to 6.8–7.0 km/s at the base of the crust. The Moho is found at a depth of 33.5–35 km beneath the profile, and mantle velocities are high at 8.05–8.10 km/s.
Imaging the Nechako Basin, British Columbia, using ambient seismic noise1This article is one of a series of papers published in this Special Issue on the theme of New insights in Cordilleran Intermontane geoscience: reducing exploration risk in the mountain pine beetle-affected area, British Columbia.
Authors: Idowu O.A. , Frederiksen A.W. , Cassidy J.F. 
Published: July 2011

The Nechako Basin in British Columbia, Canada is suspected to have hydrocarbon potential. However, it has been a difficult basin to explore because of the presence of Tertiary volcanic outcrop. The volcanic outcrop makes the use of conventional seismic exploration methods difficult owing to a strong velocity inversion at its base. An alternative is the passive source method known as ambient noise surface wave tomography. The method, which examines the high-frequency surface wave field that is obtained from noise analysis, is sensitive to large-scale crustal structure and has been successfully applied to measuring the depths of sedimentary basins. Station-to-station Green’s functions within the basin were estimated by cross-correlating the vertical components of the seismic noise data recorded by 12 POLARIS (Portable Observatories for Lithosphere Analysis and Research Investigating Seismicity) and CNSN (Canadian National Seismgraph Network) seismic stations between September 2006 and November 2007. The resulting Green’s functions were dominated by Rayleigh waves. The dispersion characteristics of the Rayleigh waveforms were measured within the microseismic band. Inversion of the dispersion curves produced 1-D and 2-D thickness models and 2-D group velocity models for the Nechako Basin and its surrounding region. The velocity models indicate two low group velocity structures within the basin that might represent sedimentary packages, and some pockets of high-velocity zones that show the presence of volcanic rocks within and on the basin. The thickness models indicated the presence of about six different velocity layers, in which the average thickness of the basin and the crust are ∼4.8 and 30–34 km, respectively.
Current status of factors leading to team performance of on-site construction professionals in Alberta building construction projects
Authors: Hewage Kasun N. , Gannoruwa Anupama , Ruwanpura Janaka Y. 
Published: July 2011

A skill-measuring criterion or strategy can be used to optimize the scarce skilled labour force in the Canadian construction industry. The University of Calgary conducted an extensive study to assess the skill levels and team performance of field workers and managers in Alberta’s building construction projects. Over 150 workers and field managers were interviewed, surveyed with questionnaires and observed, to identify team efficiencies, skill levels, team spirit, and team perceptions of supervision. The average construction worker had over 15 years of field experience. Most of the workers were high school educated. More than 70% of the workers wanted to improve their career skills; however, internal and external opportunities were limited and (or) not promoted by the respective construction companies. A very few foremen had certified skills in administration, computer handling, planning, job management and work records. The research clearly noted the urgent need for training programs, for workers and field managers, to improve their present skill levels.
SUBCRITICAL PATTERN FORMATION IN GRANULAR FLOW
Authors: KANELLOPOULOS GIORGOS , VAN DER WEELE KO 
Published: July 2011

We study a minimal model for the flow of granular material on a conveyor belt consisting of a staircase-like array of K vertically vibrated compartments. Applying a steady inflow rate Q to the top compartment, we determine the maximum value Q cr (K) for which a continuous flow through the system is possible. Beyond Q cr (K), which depends on the vibration strength and the dimensions of the system, a dense cluster forms in one of the first compartments and obstructs the flow. We find that the formation of this cluster is already announced belowQ cr (K) by the appearance of an oscillatory density profile along the entire length of the conveyor belt, with a distinct two-compartment wavelength. These model predictions concerning the breakdown of the granular flow admit an elegant explanation in terms of bifurcation theory. In particular, the subcritical oscillatory pattern is shown to be a side effect of the period doubling bifurcation by which the uniform density profile (associated with a smooth particle flow) becomes unstable. The effect turns out to be robust enough to survive the presence of a reasonable amount of noise and even certain qualitative modifications to the flux model. The density oscillations may therefore well be of practical value and provide a warning signal for imminent clustering on actual conveyor belts.
Water-quality trends for a stream draining the Southern Anthracite Field, Pennsylvania
Authors: Cravotta C. A. , Bilger M. D. 
Published: July 2011

Stream flow, chemical and biological data for the northern part of Swatara Creek, which drains a 112 km
2
area in the Southern Anthracite Field of eastern Pennsylvania, indicate progressive improvement in water quality since 1959, after which most mines in the watershed had been flooded. Drainage from the flooded mines contributes substantially to base flow in Swatara Creek. Beginning in 1995, a variety of treatment systems and surface reclamation were implemented at some of the abandoned mines. At Ravine, Pa., immediately downstream of the mined area, median SO
4
concentration declined from about 150 mg l
−1
in 1959 to 75 mg l
−1
in 1999 while pH increased from acidic to near-neutral values (medians:
c.
pH 4 before 1975;
c.
pH 6 after 1975). Fish populations rebounded from non-existent during 1959–1990 to 21 species identified in 1999. Nevertheless, recent monitoring indicates (1) episodic acidification and elevated concentrations and transport of Fe, Al, Mn, and trace metals during storm flow; (2) elevated concentrations of Fe, Mn, Co, Cu, Pb, Ni, and Zn in streambed sediments relative to unmined areas and to toxicity guidelines for aquatic invertebrates and fish; and (3) elevated concentrations of metals in fish tissue, notably Zn. The metals are ubiquitous in the fine fraction (<0.063 mm) of bed sediment in mining-affected tributaries and the main stem of Swatara Creek. As a result of scour and transport of streambed deposits, concentrations of suspended solids and total metals in the water column are correlated, and those for storm flow typically exceed base flow. Nevertheless, the metals concentrations are poorly correlated with stream flow because concentrations of suspended solids and total metals typically peak prior to peak stream stage. In contrast, SO
4
, specific conductance and pH are inversely correlated with stream flow as a result of dilution of poorly buffered stream water with weakly acidic storm runoff derived mainly from low-pH rainfall. Declines in pH to values approaching 5.0 during storm flow events or declines in redox potential during burial of sediment could result in the remobilization of metals associated with suspended solids and streambed deposits.
Ferrous oxidation chemistry in passive abiotic systems for the treatment of mine drainage
Authors: Dempsey Brian A. , Roscoe Heath C. , Ames Ryan , Hedin Robert , Jeon Byong-Hun 
Published: July 2011

The rates of chemical oxidation and gas transfer were determined for two passive abiotic systems for the treatment of mine drainage. One system (HB) is a series of ponds whose discharge was net acidic. The second treatment system (CK) has shallow channels and net alkaline discharge. The O
2
mass transfer coefficient was 2 cm h
−1
for HB Pond #2 and ranged from 4 to 40 cm h
−1
for the CK channels, depending on channel velocity and depth. The CO
2
mass transfer coefficient was 1.3 cm h
−1
for HB Pond #2 and ranged from 1.4 to 15 cm h
−1
for the CK channels. Oxygen transfer appeared to be the rate-limiting step for oxidation of Fe(II) at HB Pond #2. The oxidation rate for Fe(II) adsorbed to already-formed ferric oxides (heterogeneous oxidation) appeared to control the rate of oxidation of Fe(II) at the CK channels. Based on field data, the heterogeneous rate constant for oxidation of Fe(II) was 6.0×10
−9
mg l
−1
s
−1
at 17°C or k
2
of 5.5×10
−8
mg l
−1
s
−1
at 25°C. This value was consistent with previously reported values for k
2
based on laboratory experiments. The annual-averaged iron removal rates were 18 g d
−1
m
−2
for HB and 42 g d
−1
m
−2
for CK, compared to empirical design expectations of 10 to 20 g d
−1
m
−2
. Heterogeneous oxidation accounted for >80 of the oxidation of Fe(II) at HB and >90% of the oxidation of Fe(II) at CK.
A fractal filtering technique for processing regional geochemical maps for mineral exploration
Authors: Xu Yaguang , Cheng Qiuming 
Published: July 2011

A regional geochemical map interpolated from point data, usually sampled in surficial media such as stream sediments or lake sediments, may contain a large amount of information critical for mineral exploration and environmental studies. The geochemical map is, however, not ‘ready-to-use’ for such tasks as the determination of a local ‘anomaly’ or the characterization of a regional trend of one or more chemical elements as may be required for the purpose of mineral resource prediction. This becomes possible only after the map has been clearly divided into different components. Fractal filtering, a recently developed technique for decomposing a map or image into different components, helps to separate the anomaly from background or to extract other meaningful patterns from the geochemical map using both frequency and spatial information.
The fractal filters are formed by applying the fractal concentration-area model to the power spectrum of the processed geochemical field. They often constitute a group of irregularly shaped filters in the frequency domain that can separate the domain of wave numbers into distinct regions, each with a power spectrum following a similar power-law or fractal property. The corresponding patterns of the separate components are obtained after transformation back to the spatial domain.
The fractal filter can be applied to decompose the original geochemical field into a set of map components with distinct scaling ranges and anisotropy. The analysis of relationships among these decomposed maps can provide useful information for the interpretation and evaluation of anomalies or trends.
This paper briefly introduces the theory behind the fractal filtering technique. A case study of regional geochemical data of lake sediments from western Meguma Terrain, Southern Nova Scotia, Canada, is used to illustrate application of this technique to process the regional geochemical maps of the study area for the prediction of the turbidite-hosted gold deposits.
Regolith evolution and geochemical dispersion in transported and residual regolith – Bronzewing gold deposit
Authors: Anand R. R. , Wildman J. E. , Varga Z. S. , Phang C. 
Published: July 2011

Geochemical dispersion in the regolith was investigated at the Bronzewing gold deposit in a variety of geomorphological environments. A series of economic gold deposits are concealed by 5–35 m of sediments, and a thick residual profile about 100 m thick. Prior to mining, samples of regolith materials were collected from surface and drill cuttings, along several lines over the north–south trending, elongate zone of mineralization. These samples were examined in detail to determine element distributions, their relationship to regolith evolution and their significance to exploration.
The residual materials (lateritic residuum and ferruginous saprolite) have Au, W and Cu anomalies in the vicinity of the deposit. Elements associated with the Au mineralization in the lateritic residuum of the Laterite Pit are Ag, Ba, Ce, W, Mo, As, Sb and Cu. Gold anomalies in lateritic residuum are less consistent in the Discovery Pit and, at both the Central and Discovery Pits, are enriched in Cu and W only close to the weathered primary mineralization. Three-dimensional modelling indicates that Au in saprolite is localized and largely residual. Geochemical dispersion from primary mineralization into the sediments is only minor, except immediately overlying the lateritic residuum or saprolite. This dispersion is, however, almost entirely mechanical and there appears to have been little, if any, post-depositional chemical dispersion. Ferruginous mottles developed in palaeochannel sediments have very low Au contents (<5 ppb) but are slightly enriched in Cu. There is a significant concentration of Au (up to 300 ppb) in authigenic smectites formed at the residual-transported interface. The deposits are blind to soil sampling (10–30 cm depth) using total and several partial extraction techniques.
The results demonstrate that dispersion of ore-related elements at Bronzewing is mostly confined to the lateritic residuum and ferruginous saprolite and that sampling of these materials, even if buried beneath transported overburden, will readily locate deposits of this type. However, it is important to distinguish between residual and transported regolith, especially nodules and pisoliths. In the absence of residual materials, sampling of the lowermost sedimentary units (gravelly sediments), possibly including the unconformity, is recommended because it may show the geochemical dispersion that is wider than the primary anomaly in saprolite or bedrock. The results also provide strong support for the use of multi-element geochemistry, with elements such as Cu and W being enriched close to primary mineralization.
Geochemical exploration around the Harmony gold deposit, Peak Hill, Western Australia
Authors: Robertson I. D. M. 
Published: July 2011

Primary Au mineralization at Harmony is associated with sulphide-poor quartz veins in mafic and ultramafic rocks. Gold and W are the most significant indicators of mineralization in fresh rock. Elements associated with the phyllic alteration halo are K, Rb and Ba, and Eu, Lu and Yb; these increase in abundance and range near mineralization. Although As and Sb are elevated, their abundances are far lower than in sulphide-rich mineralization styles. The Harmony gold deposit was completely covered by a blanket of soil and colluvium. Drilling beneath this revealed a complex, partly eroded residual regolith, clay-rich valley fill sediments and colluvium.
Sampling and analysis of the top of the basement (ferruginous saprolite, lateritic residuum and mottles washed from the mottled zone) on a 250 m sample spacing showed significant Au and W anomalies in the vicinity of the deposit. Gold dispersion in the ferruginous saprolite is restricted and requires close-spaced sampling (50 m).
The unconformity between the stripped basement and colluvium was sampled at a 150 m spacing to capitalize on any mechanical or hydromorphic dispersion along the contact. Dispersion of Au, W, Ta and Nb along this interface, indicating mechanical down-slope migration, produced better and more consistent anomalies than the basement sampling in this stripped environment. There are some very weak Au anomalies in the fine soil fraction (<75 μm), where the colluvial cover over the Harmony deposit was extremely thin (<2 m). However, this cannot be relied upon to locate mineralization.
Weathering in the Parkinson Pit and its implications for exploration in the Mt Magnet Mining District, Western Australia
Authors: Scott K. M. 
Published: July 2011

In the Parkinson Pit area at Mt Magnet, 560 km NNE of Perth, mafic and felsic rocks occur within a weathering profile that has been stripped to the saprolite. Irrespective of rock type within the pit area, the weathered profile consists of fresh rock, saprock, mottled saprolite and leached saprolite below a thin transported soil cover. The depth of weathering extends to 80 m adjacent to mineralization, although weathering depths appear to be less in mafic volcanic rocks outside the pit.
Weathering has led to separation of Ag from the primary Ag-bearing gold and the redistribution of other potential pathfinders elements (As, Co, Cu, Ni, Sb and Zn ) from the original sulphides (mainly pyrite) into Fe and Mn oxides. Gold grades have not been significantly affected by weathering.
Both mafic and felsic rocks in the Parkinson Pit area, have been metamorphosed to quartz+chlorite±mica+albite assemblages. However, hydrothermal alteration has destroyed albite and formed additional mica, so that the change: minor muscovite→paragonite±muscovite→muscovite, reflects an approach to mineralization. Because micas are retained when the rocks weather, this characteristic feature is maintained in the regolith, although changes in mica compositions and abundance are more obvious in mafic than in felsic rocks because of the greater initial mica content in the latter. Thus, proximity to mineralization, reflected by mica composition and abundance in mafic volcanic rocks, could be determined by PIMA and radiometric analysis of K content, even from weathered drill cuttings.
PTEN Positively Regulates UVB-Induced DNA Damage Repair
Authors: Ming Mei , Feng Li , Shea Christopher R. , Soltani Keyoumars , Zhao Baozhong , Han Weinong , Smart Robert C. , Trempus Carol S. , He Yu-Ying 
Published: July 2011

Abstract
Nonmelanoma skin cancer is the most common cancer in the United States, where DNA-damaging ultraviolet B (UVB) radiation from the sun remains the major environmental risk factor. However, the critical genetic targets of UVB radiation are undefined. Here we show that attenuating PTEN in epidermal keratinocytes is a predisposing factor for UVB-induced skin carcinogenesis in mice. In skin papilloma and squamous cell carcinoma (SCC), levels of PTEN were reduced compared with skin lacking these lesions. Likewise, there was a reduction in PTEN levels in human premalignant actinic keratosis and malignant SCCs, supporting a key role for PTEN in human skin cancer formation and progression. PTEN downregulation impaired the capacity of global genomic nucleotide excision repair (GG-NER), a critical mechanism for removing UVB-induced mutagenic DNA lesions. In contrast to the response to ionizing radiation, PTEN downregulation prolonged UVB-induced growth arrest and increased the activation of the Chk1 DNA damage pathway in an AKT-independent manner, likely due to reduced DNA repair. PTEN loss also suppressed expression of the key GG-NER protein xeroderma pigmentosum C (XPC) through the AKT/p38 signaling axis. Reconstitution of XPC levels in PTEN-inhibited cells restored GG-NER capacity. Taken together, our findings define PTEN as an essential genomic gatekeeper in the skin through its ability to positively regulate XPC-dependent GG-NER following DNA damage. Cancer Res; 71(15); 5287–95. ©2011 AACR.
Clusterin Inhibition Using OGX-011 Synergistically Enhances Hsp90 Inhibitor Activity by Suppressing the Heat Shock Response in Castrate-Resistant Prostate Cancer
Authors: Lamoureux Francois , Thomas Christian , Yin Min-Jean , Kuruma Hidetoshi , Beraldi Eliana , Fazli Ladan , Zoubeidi Amina , Gleave Martin E. 
Published: July 2011

Abstract
Small-molecule inhibitors of Hsp90 show promise in the treatment of castrate-resistant prostate cancer (CRPC); however, these inhibitors trigger a heat shock response that attenuates drug effectiveness. Attenuation is associated with increased expression of Hsp90, Hsp70, Hsp27, and clusterin (CLU) that mediate tumor cell survival and treatment resistance. We hypothesized that preventing CLU induction in this response would enhance Hsp90 inhibitor–induced CRPC cell death in vitro and in vivo. To test this hypothesis, we treated CRPC with the Hsp90 inhibitor PF-04929113 or 17-AAG in the absence or presence of OGX-011, an antisense drug that targets CLU. Treatment with either Hsp90 inhibitor alone increased nuclear translocation and transcriptional activity of the heat shock factor HSF-1, which stimulated dose- and time-dependent increases in HSP expression, especially CLU expression. Treatment-induced increases in CLU were blocked by OGX-011, which synergistically enhanced the activity of Hsp90 inhibition on CRPC cell growth and apoptosis. Accompanying these effects was a decrease in HSF-1 transcriptional activity as well as expression of HSPs, Akt, prostate-specific antigen, and androgen receptor. In vivo evaluation of the Hsp90 inhibitors with OGX-011 in xenograft models of human CRPC showed that OGX-011 markedly potentiated antitumor efficacy, leading to an 80% inhibition of tumor growth with prolonged survival compared with Hsp90 inhibitor monotherapy. Together, our findings indicate that Hsp90 inhibitor–induced activation of the heat shock response and CLU is attenuated by OGX-011, with synergistic effects on delaying CRPC progression. Cancer Res; 71(17); 5838–49. ©2011 AACR.