bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrovirus Restriction by TRIM5α Variants from Old World and New World Primates
Authors: Song Byeongwoon , Javanbakht Hassan , Perron Michel , Park Do Hyun , Stremlau Matthew , Sodroski Joseph
Published: March 2005

The TRIM5α proteins of humans and some Old World monkeys have been shown to block infection of particular retroviruses following virus entry into the host cell. Infection of most New World monkey cells by the simian immunodeficiency virus of macaques (SIV
mac
) is restricted at a similar point. Here we examine the antiretroviral activity of TRIM5α orthologs from humans, apes, Old World monkeys, and New World monkeys. Chimpanzee and orangutan TRIM5α proteins functionally resembled human TRIM5α, potently restricting infection by N-tropic murine leukemia virus (N-MLV) and moderately restricting human immunodeficiency virus type 1 (HIV-1) infection. Notably, TRIM5α proteins from several New World monkey species restricted infection by SIV
mac
and the SIV of African green monkeys, SIV
agm
. Spider monkey TRIM5α, which has an expanded B30.2 domain v3 region due to a tandem triplication, potently blocked infection by a range of retroviruses, including SIV
mac
, SIV
agm
, HIV-1, and N-MLV. Tandem duplications in the TRIM5α B30.2 domain v1 region of African green monkeys are also associated with broader antiretroviral activity. Thus, variation in TRIM5α proteins among primate species accounts for the observed patterns of postentry restrictions in cells from these animals. The TRIM5α proteins of some monkey species exhibit dramatic lengthening of particular B30.2 variable regions and an expanded range of susceptible retroviruses.
ICP27 Recruits Aly/REF but Not TAP/NXF1 to Herpes Simplex Virus Type 1 Transcription Sites although TAP/NXF1 Is Required for ICP27 Export
Authors: Chen I-Hsiung Brandon , Li Ling , Silva Lindsey , Sandri-Goldin Rozanne M.
Published: March 2005

Herpes simplex virus type 1 (HSV-1) protein ICP27 interacts with the cellular export adaptor protein Aly/REF, which is part of the exon junction complex implicated in cellular mRNA export. We previously reported that Aly/REF was no longer associated with splicing factor SC35 sites during infection but instead colocalized with ICP27 in distinct structures. Here we show that these structures colocalize with ICP4 and are sites of HSV-1 transcription. ICP27 mutants with lesions in the region required for the interaction with Aly/REF failed to recruit Aly/REF to viral transcription sites; however, ICP27 export to the cytoplasm was unimpaired, indicating that the interaction of ICP27 with Aly/REF is not required for ICP27 shuttling. ICP27 has also been shown to interact with the cellular mRNA export receptor TAP/NXF1. We report that ICP27 interacts directly with TAP/NXF1 and does not require Aly/REF to bridge the interaction. The C terminus of ICP27 is required; however, the N-terminal leucine-rich region also contributes to the interaction of ICP27 with TAP/NXF1. In contrast to the results found for Aly/REF, mutants that failed to interact with TAP/NXF1 were not exported to the cytoplasm, and TAP/NXF1 was not recruited to sites of HSV-1 transcription. Therefore, the interaction of ICP27 with TAP/NXF1 occurs after ICP27 leaves viral transcription sites. We conclude that ICP27 and the viral RNAs to which it binds are exported via the TAP/NXF1 export receptor.
Inhibition of RIG-I-Dependent Signaling to the Interferon Pathway during Hepatitis C Virus Expression and Restoration of Signaling by IKKε
Authors: Breiman Adrien , Grandvaux Nathalie , Lin Rongtuan , Ottone Catherine , Akira Shizuo , Yoneyama Mitsutoshi , Fujita Takashi , Hiscott John , Meurs Eliane F.
Published: March 2005

Interferon (IFN) is one important effector of the innate immune response, induced by different viral or bacterial components through Toll-like receptor (TLR)-dependent and -independent mechanisms. As part of its pathogenic strategy, hepatitis C virus (HCV) interferes with the innate immune response and induction of IFN-β via the HCV NS3/4A protease activity which inhibits phosphorylation of IRF-3, a key transcriptional regulator of the IFN response. In the present study, we demonstrate that inhibition by the protease occurs upstream of the noncanonical IKK-related kinases IKKε and TBK-1, which phosphorylate IRF-3, through partial inhibition of the TLR adapter protein TRIF/TICAM1-dependent pathway. Use of TRIF
−/−
mouse embryo fibroblasts however revealed the presence of a TRIF-independent pathway involved in IFN induction that was also inhibited by NS3/4A. Importantly, we show that NS3/4A can strongly inhibit the ability of the recently described RIG-I protein to activate IFN, suggesting that RIG-I is a key factor in the TRIF-independent, NS3/4A-sensitive pathway. Expression of IFN signaling components including IKKε, TBK-1, TRIF, and wild type or constitutively active forms of RIG-I in the HCV replicon cells resulted in IFN-β promoter transactivation, with IKKε displaying the highest efficiency. Subsequently, overexpression of IKKε resulted in 80% inhibition of both the positive and negative replicative strands of the HCV replicon. The partial restoration of the capacity of the host cell to transcribe IFN-β indicates that IKKε expression is able to bypass the HCV-mediated inhibition and restore the innate antiviral response.
Expression of Glucose Transporter 1 Confers Susceptibility to Human T-Cell Leukemia Virus Envelope-Mediated Fusion
Authors: Coskun Ayse Kubra , Sutton Richard E.
Published: March 2005

Human T-cell leukemia virus type 1 (HTLV-1) was the first human retrovirus identified and causes both adult T-cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-1-associated myelopathy, among other disorders. In vitro, HTLV-1 has an extremely broad host cell tropism in that it is capable of infecting most mammalian cell types, although at the same time viral titers remain relatively low. Despite years of study, only recently has a bona fide candidate cellular receptor, glucose transporter 1 (glut-1), been identified. Although glut-1 was shown to bind specifically to the ectodomain of HTLV-1 and HTLV-2 envelope glycoproteins, which was reversible with small interfering RNA directed against glut-1, cellular susceptibility to HTLV upon expression of glut-1 was not established. Here we show that expression of glut-1 in relatively resistant MDBK cells conferred increased susceptibility to both HTLV-1- and HTLV-2-pseudotyped particles. glut-1 also markedly increased syncytium formation in MDBK cells after exposure to HTLV-1. Another assay also demonstrated HTLV-1 envelope-cell fusion in the presence of glut-1. Taken together, these results provide additional evidence that glut-1 is a receptor for HTLV.
Activation of CREB/ATF Sites by Polyomavirus Large T Antigen
Authors: Love Tara M. , de Jesus Rowena , Kean Jennifer A. , Sheng Qing , Leger Andrew , Schaffhausen Brian
Published: March 2005

Polyomavirus large T antigen (LT) has a direct role in viral replication and a profound effect on cell phenotype. It promotes cell cycle progression, immortalizes primary cells, blocks differentiation, and causes apoptosis. While much of large T function is related to its effects on tumor suppressors of the retinoblastoma susceptibility (Rb) gene family, we have previously shown that activation of the cyclin A promoter can occur through a non-Rb-dependent mechanism. Here we show that activation occurs via an ATF/CREB site. Investigation of the mechanism indicates that large T can synergize with CREB family members to activate transcription. Experiments with Gal4-CREB constructs show that synergy is independent of CREB phosphorylation by protein kinase A. Examination of synergy with Gal4-CREB deletion constructs indicates that large T acts on the constitutive activation domain of CREB. Large T can bind to CREB in vivo. Genetic analysis shows that the DNA-binding domain (residues 264 to 420) is sufficient to activate transcription when it is localized to the nucleus. Further analysis of the DNA-binding domain shows that while site-specific DNA binding is not required, non-site-specific DNA binding is important for the activation. Thus, CREB binding and DNA binding are both important for large T activation of CREB/ATF sites. In contrast to previous models where large T transactivation occurred indirectly, these results also suggest that large T can act directly at promoters to activate transcription.
Human Papillomavirus Type 18 E6 Protein Binds the Cellular PDZ Protein TIP-2/GIPC, Which Is Involved in Transforming Growth Factor β Signaling and Triggers Its Degradation by the Proteasome
Authors: Favre-Bonvin Arnaud , Reynaud Caroline , Kretz-Remy Carole , Jalinot Pierre
Published: March 2005

Several viral proteins expressed by DNA or RNA transforming viruses have the particular property of binding via their C-terminal end to various cellular proteins with PDZ domains. This study is focused on the PDZ protein TIP-2/GIPC, which was originally identified in two-hybrid screens performed with two different baits: the human T-cell leukemia virus type 1 Tax oncoprotein and the regulator of G signaling RGS-GAIP. Further studies have shown that TIP-2/GIPC is also able to associate with the cytoplasmic domains of various transmembrane proteins. In this report we show that TIP-2/GIPC interacts with the E6 protein of human papillomavirus type 18 (HPV-18). This event triggers polyubiquitination and proteasome-mediated degradation of the cellular protein. In agreement with this observation, silencing of E6 by RNA interference in HeLa cells causes an increase in the intracellular TIP-2/GIPC level. This PDZ protein has been previously found to be involved in transforming growth factor β (TGF-β) signaling by favoring expression of the TGF-β type III receptor at the cell membrane. In line with this activity of TIP-2/GIPC, we observed that depletion of this protein in HeLa cells hampers induction of the
Id3
gene by TGF-β treatment and also diminishes the antiproliferative effect of this cytokine. Conversely, silencing of E6 increases the expression of Id3 and blocks proliferation of HeLa cells. These results support the notion that HPV-18 E6 renders cells less sensitive to the cytostatic effect of TGF-β by lowering the intracellular amount of TIP-2/GIPC.
TFII-I Regulates Induction of Chromosomally Integrated Human Immunodeficiency Virus Type 1 Long Terminal Repeat in Cooperation with USF
Authors: Chen Jiguo , Malcolm Tom , Estable Mario C. , Roeder Robert G. , Sadowski Ivan
Published: March 2005

Human immunodeficiency virus type 1 (HIV-1) replication is coupled to T-cell activation through its dependence on host cell transcription factors. Despite the enormous sequence variability of these factors, several
cis
elements for host factors are highly conserved within the 5′ long terminal repeats (LTRs) of viruses from AIDS patients; among these is the RBEIII upstream element for the Ras response element binding factor 2 (RBF-2). Here we show that RBF-2 is comprised of a USF1/USF2 heterodimer and TFII-I, which bind cooperatively to RBEIII. Recombinant USF1/USF2 binds to the RBEIII core sequence 160-fold less efficiently than it binds to an E box element, but the interaction with RBEIII is stimulated by TFII-I. Chromosomally integrated HIV-1 LTRs bearing an RBEIII mutation have slightly elevated basal transcription in unstimulated Jurkat cells but are unresponsive to cross-linking of the T-cell receptor or stimulation with phorbol myristate acetate (PMA) and ionomycin. Induction is inhibited by dominant interfering USF and TFII-I but not by the dominant negative I-κB protein. USF1, USF2, and TFII-I bind to the integrated wild-type LTR in unstimulated cells and become phosphorylated during the induction of transcription upon stimulation with PMA. These results demonstrate that USF1/USF2 and TFII-I interact cooperatively at the upstream RBEIII element and are necessary for the induction of latent HIV-1 in response to T-cell activation signals.
Epstein-Barr Virus Transforming Protein LMP1 Plays a Critical Role in Virus Production
Authors: Ahsan Nazmul , Kanda Teru , Nagashima Kazuo , Takada Kenzo
Published: March 2005

The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1), which is critical for EBV-induced B-cell transformation, is also abundantly expressed during the lytic cycle of viral replication. However, the biological significance of this strong LMP1 induction remains unknown. We engineered a bacterial artificial chromosome clone containing the entire genome of Akata strain EBV to specifically disrupt the LMP1 gene. Akata cell clones harboring the episomes of LMP1-deleted EBV were established, and the effect of LMP1 loss on virus production was investigated. We found that the degree of viral DNA amplification and the expression levels of viral late gene products were unaffected by LMP1 loss, demonstrating that the LMP1-deleted EBV entered the lytic replication cycle as efficiently as the wild-type counterpart. This was confirmed by our electron microscopic observation that nucleocapsid formation inside nuclei occurred even in the absence of LMP1. By contrast, loss of LMP1 severely impaired virus release into culture supernatants, resulting in poor infection efficiency. The expression of truncated LMP1 in Akata cells harboring LMP1-deleted EBV rescued the virus release into the culture supernatant and the infectivity, and full-length LMP1 partially rescued the infectivity. These results indicate that inducible expression of LMP1 during the viral lytic cycle plays a critical role in virus production.
RNA Polymerase I-Driven Minigenome System for Ebola Viruses
Authors: Groseth Allison , Feldmann Heinz , Theriault Steven , Mehmetoglu Gülsah , Flick Ramon
Published: March 2005

In general, Ebola viruses are well known for their ability to cause severe hemorrhagic fever in both human and nonhuman primates. However, despite substantial sequence homology to other members of the family
Filoviridae
,
Reston ebolavirus
displays reduced pathogenicity for nonhuman primates and has never been demonstrated to cause clinical disease in humans, despite its ability to cause infection. In order to develop a tool to explore potential roles for transcription and replication in the reduced pathogenicity of
Reston ebolavirus
, we developed an RNA polymerase I (Pol I)-driven minigenome system. Here we demonstrate successful
Reston ebolavirus
minigenome rescue, including encapsidation, transcription, and replication, as well as the packaging of minigenome transcripts into progeny particles. The Pol I-driven
Reston ebolavirus
minigenome system provides a higher signal intensity with less background (higher signal-to-noise ratio) than a comparable T7-driven
Reston ebolavirus
minigenome system which was developed simultaneously. Successful
Reston ebolavirus
minigenome rescue was also achieved by the use of helper plasmids derived from the closely related
Zaire ebolavirus
or the more distantly related
Lake Victoria marburgvirus
. The use of heterologous helper plasmids in the
Reston ebolavirus
minigenome system yielded levels of reporter expression which far exceeded the level produced by the homologous helper plasmids. This comparison between minigenomes and helper plasmids from different filovirus species and genera indicates that inherent differences in the transcription and/or replication capacities of the ribonucleoprotein complexes of pathogenic and apathogenic filoviruses may exist, as these observations were confirmed in a
Lake Victoria marburgvirus
minigenome system.
Herpes Simplex Virus Entry Mediator Associates in Infected Cells in a Complex with Viral Proteins gD and at Least gH
Authors: Perez-Romero Pilar , Perez Aleida , Capul Althea , Montgomery Rebecca , Fuller A. Oveta
Published: March 2005

We examined herpes simplex virus (HSV)-infected human HEp-2 cells or porcine cells that express herpes virus entry mediator (HVEM) for virus and receptor protein interactions. Antibody to HVEM, or its viral ligand gD, coimmunoprecipitated several similar proteins. A prominent 110-kDa protein that coprecipitated was identified as gH. The HVEM/gD/gH complex was detected with mild or stringent cell lysis conditions. It did not form in cells infected with HSV-1(KOS)Rid1 virus or with null virus lacking gD, gH, or gL. Thus, in cells a complex forms through physical associations of HVEM, gD, and at least gH.
$K\bar{K}$ PRODUCTION AT COSY
Authors:   FOR THE ANKE COLLABORATION: For the ANKE Collaboration list see, KLEBER VERA
Published: March 2005

Near threshold [Formula: see text] production has been studied in several hadronic reactions at COSY. Data on pp→ppK+K- and pd→3HeK+K- are available at several excess energies. ϕ mesons are clearly observed whereas the contribution from the scalar resonances a0/f0(980) is unclear. Data on [Formula: see text] were measured at two excess energies and for the lower energy the total cross section as well as differential distributions have been extracted. The main contribution to this reaction is identified as the [Formula: see text] channel. Furthermore, the differential distributions may give information on the [Formula: see text] FSI and scattering length. The data at the higher energy are still under analysis, and a preliminary value for the total cross section is given. [Formula: see text] production in pn reactions is also investigated in a recently performed measurement.
RECENT RESULTS FROM THE KLOE EXPERIMENT
Authors:   FOR THE KLOE COLLABORATION: The KLOE Collaboration: A. Aloisio, F. Ambrosino, A. Antonelli, M. Antonelli, C. Bacci, G. Bencivenni, S. Bertolucci, C. Bini, C. Bloise, V. Bocci, F. Bossi, P. Branchini, S. A. Bulychjov, R. Caloi, P. Campana, G. Capon, T. Capussela, G. Carboni, F. Ceradini, F. Cervelli, F. Cevenini, G. Chiefari, P. Ciambrone, S. Conetti, E. De Lucia, P. De Simone, G. De Zorzi, S. Dell'Agnello, A. Denig, A. Di Domenico, C. Di Donato, S. Di Falco, B. Di Micco, A. Doria, M. Dreucci, O. Erriquez A, LANFRANCHI GAIA
Published: March 2005

Recent results obtained by the KLOE experiment operating at DAΦNE, the Frascati ϕ-factory, are presented. They mainly concern neutral kaon decays including rare KS decays, KL lifetime, the radiative ϕ→f0γ decay and the measurement of the e+e- hadronic cross section using initial state radiation.
THE PANDA DETECTOR AT THE GSI-FAIR PROJECT
Authors:   FOR THE PANDA COLLABORATION., RITMAN JAMES
Published: March 2005

A major component of the approved upgrade of the GSI facility in Darmstadt, Germany is the High Energy Storage Ring (HESR) for high intensity, phase space cooled antiprotons with momenta up to 15 GeV/c. At this facility a wide physics program is planned to investigate both the structure of hadrons in the charmonium mass range and the spectroscopy of double hypernuclei. To serve the many experiments planned at this new facility, a general purpose detector called PANDA (Proton ANtiproton Detector Array) is planned. An overview of the PANDA detector concept, as well as selected results from simulation of the detector's performance will be presented.
STUDY OF ρ AND ω MESON CONVERSION DECAYS WITH THE CMD-2 DETECTOR AT THE VEPP-2M COLLIDER
Authors:   ON BEHALF OF THE CMD-2 COLLABORATION., KAZANINE VASSILI
Published: March 2005

In 2000 a large statistical sample of about 3.4 pb -1 was collected in the 720—840 MeV c.m. energy range with the CMD-2 detector at the VEPP-2M collider. It corresponds to 1.8·106ω meson decays. This data sample was used to study the ρ and ω meson conversion decays. The measured branching fraction for the ω→π0e+e- decay mode agrees with the previous result of the ND detector but has about two times better accuracy. Upper limits for the decay modes ρ→π0e+e- and ρ,ω→ηe+e- were set for the first time.
Spectral reflectance properties (0.4–2.5 μm) of secondary Fe-oxide, Fe-hydroxide, and Fe-sulphate-hydrate minerals associated with sulphide-bearing mine wastes
Authors: Crowley J.K. , Williams D.E. , Hammarstrom J.M. , Piatak N. , Chou I-Ming , Mars J.C.
Published: March 2005

Diffuse reflectance spectra of 15 mineral species commonly associated with sulphide-bearing mine wastes show diagnostic absorption bands related to electronic processes involving ferric and/or ferrous iron, and to vibrational processes involving water and hydroxyl. Many of these absorption bands are relatively broad and overlapping; however, spectral analysis methods, including continuum removal and derivative analysis, permit most of the minerals to be distinguished. Key spectral differences between the minerals are illustrated in a series of plots showing major absorption band centres and other spectral feature positions. Because secondary iron minerals are sensitive indicators of pH, Eh, relative humidity, and other environmental conditions, spectral mapping of mineral distributions promises to have important application to mine waste remediation studies.
Geochemical signature of mineralization in weathered sediments and bedrock, Thunderdome prospect, Broken Hill region, westernNew South Wales, Australia: implications for mineral explorationunder cover
Authors: Tonui Eric , Caritat Patrice de , Leyh Wolfgang
Published: March 2005

The stratiform Pb–Ag–Zn and stratabound Cu–Au mineralization of the Thunderdome prospect, located in the Mundi Mundi Plain 50 km NW of Broken Hill, NSW, is covered by
c.
200 m of sediments. A downhole mineralogical and geochemical dispersion study was carried out on 245 regolith samples from six exploration drillholes to establish if geochemical dispersion from the mineralization could be identified in the overlying cover. This was achieved using a combination of qualitative and quantitative XRD, Portable Infrared Mineral Analyzer (PIMA) and XRF techniques. The stratigraphy is defined by a variable thickness of diagenetically modified and weathered Cenozoic sediments (and soil) overlying the weathered Proterozoic basement, which hosts the mineralization. The composition of the sediments and saprolite appears to have been influenced by chemical dispersion from underlying mineralization, as shown by anomalous concentrations of Cu (up to
c.
13 times above background), Ni (
c.
9 times), As, Zn, Pb and Co (all
c.
3 times) among others. Some of these anomalies are widespread and may be either clastic or related to adsorption on clay minerals, Fe-oxides and neoformed, poorly crystalline mineral phases. The precise transport mechanisms from the underlying mineralization need to be tested in order to gain further insights into geochemical dispersion processes under cover.
Depletion and enrichment of primary haloes: their importance in the genesis of and exploration for mineral deposits
Authors: Goldberg I.S. , Abramson G.Ya. , Los V.L.
Published: March 2005

The model of the primary halo that was created in the 1930s has not fundamentally changed. The primary halo of an ore deposit (ore body) is considered an environment of enrichment of ore-forming and associated elements as a result of ore genesis. However, extensive multi-element geochemical data show that the primary halo, like the positive anomaly, is only part of a complexly differentiated geochemical system. The system comprises the primary haloes of enrichment (positive anomalies) and haloes of depletion (negative anomalies) of ore-forming and other elements. However, negative anomalies have not been generally recognized for various reasons: they are combined with the background, taken to be background, or seen to be a random phenomenon, since they are not featured in the existing conceptual model of the primary halo.

The structure of geochemical systems is characterized by polar zoning, a fundamental feature of a system. Polar zoning can be defined as two separate areas (zones) within the system that are distinguished by the concentration or the composition of element or group of elements. The positive anomaly of deposit elements is the nucleus of the system. Polar zoning of the ferrous group (e.g. Sc, Ti, Cr) of elements is formed within the nucleus of the system: negative anomalies of this group of elements spatially coincide within mineralization and positive anomalies are recorded on the margin of the positive anomaly of ore-forming elements of system. The size of the geochemical ore deposit system varies, with a range between several and a few hundred square kilometers. The ore bodies are located in the nucleus of the geochemical system of the deposit.

The main criteria for the evaluation of a favorable area are based upon the linear dependence between the dimensions of the halo of depletion of the ore-forming elements and the metal reserves in the deposits. Larger ore bodies are found in systems with larger haloes of depletion. The linear dependency indicates a significant role of country rock as a source of metal.
Application of groundwater–mineral equilibrium calculationsto geochemical exploration for sediment-hosted uranium:observations from the Frome Embayment,South Australia
Authors: Pirlo Mark C. , Giblin Angela M.
Published: March 2005

This paper considers the interpretation of uranium (U) ore–mineral equilibrium calculations in groundwater to help understand ore genesis and assist exploration. Groundwater samples collected on two recent field sampling trips in the Frome Embayment region of South Australia have been analysed for major and selected trace elements. These data together with previous published data have been used to construct geochemical models of the equilibrium state of the groundwaters. Species’ activities and mineral saturation states have been estimated. Calculated species’ activities are generally in the range reported in the previous modelling by Giblin involving groundwaters from similar local sources. Our models indicate that amorphous UO
2
, rather than the ore minerals coffinite and uraninite, is the solidU mineral phase that is the likely control on groundwater U concentration. The UO
2
(am) saturation index did not show a systematic variation with ore grade or proximity to mineralization. Its use for exploration at smaller scales, where the groundwater composition is similar between sample sites and U minerals are present at various concentrations, is doubtful. Inherent limitations on the information provided by mineral saturation indices restrict their exploration application,particularly in high salinity palaeochannel groundwater environments, such as those common in Australia.
Two lithogeochemical approaches to the identification of alteration patterns at the Elura Zn–Pb–Ag deposit, Cobar, New South Wales, Australia: use of Pearce Element Ratio analysis and Isocon analysis
Authors: Whitbread M.A. , Moore C.L.
Published: March 2005

Lithogeochemical approaches to the identification of ore-related alteration can be obscured by closure effects and/or pre-existing lithological variations. Two mass balance approaches that can address these problems are Pearce Element Ratio analysis (PER) and Isocon analysis (IA). Both approaches have been applied to sedimentary rocks hosting the Elura ore-body, north of Cobar, in central-west New South Wales, Australia. Elura is an epigenetic, zinc–lead–silver deposit, (45 Mt with 8.5% Zn, 5.3% Pb, and 69 ppm Ag), hosted within Devonian siltstone–sandstone turbidites of the Cobar Basin. The ability of PER and IA to identify alteration at Elura and to navigate towards ore within altered zones is evaluated.

PER identified mineralogical controls on calcium, carbonate, potassium and aluminium. Molar Ca/Ti v. C/Ti plots segregate calcite-bearing background samples from iron–magnesium–carbonate altered rocks closer to ore. Molar K/Ti v. Al/Ti and K/Ti v. (Al–Na)/Ti diagrams show altered rock bulk compositions to be consistent with the development of muscovite, while background samples have an illite ± albite precursor. The precursor lithotype has a major influence on the intensity of alteration and resultant mineralogy of altered samples.

IA shows that carbonate carbon, Ag, As, K, Pb, Rb, Sb, Tl and Zn are strongly added to host rocks, while Na is strongly leached. Other elements show variable trends towards ore, with lithotype strongly affecting the patterns. Samples have greater mass gains closer to ore. Selection of an appropriate parent rock is critical in gaining meaningful results in IA.
Geochemical exploration for gold in Jamaica: a comparison of stream sediment and soil surveys
Authors: Garrett Robert G. , Lalor Gerald C. , Vutchkov Mitko
Published: March 2005

The geology of Jamaica is reviewed with reference to gold. Two geochemical surveys, one employing stream sediments for mineral exploration in selected regions of Jamaica considered
a priori
to have greater mineral potential, and the other an island-wide low-density soil survey to meet agro-environmental objectives, were undertaken in 1986 and 1988, respectively. The paper presents an interpretation of the previously unpublished soil data for gold, and undertakes a comparison of the two surveys in terms of their effectiveness for gold exploration. The stream sediment survey (1 site per 1 km
2
) led to the discovery of three new gold occurrences, one of which became a producing mine in 2001, and the recognition of two previously known auriferous districts. The low-density soil survey (1 site per 64 km
2
) identified the host rocks of three of these auriferous districts as having gold potential, including those of the producing mine, demonstrating its value as a broad-scale regional mineral reconnaissance tool. Geochemical studies of gold in Jamaica are complicated by the presence of transported palaeo-anomalies, related to Miocene ash-falls, in
terra rossa
soils in karst terrain. The Fe/Na ratio is an index of soil maturity and increases over two-and-a-half orders of magnitude with increasing soil age and mature. The plotting of Au versus the Fe/Na ratio in soils offers a simple procedure for identifying samples most likely to be related to gold occurrences in bedrock, i.e. high Au and low Fe/Na ratio. It is concluded that in the specific instance of Jamaica's high relief terrain and the apparent limitation of gold occurrences to the Cretaceous Inliers and Eocene Wagwater Trough underlying those high relief areas, stream sediment sampling is the most effective mineral exploration tool.
Groundwater geochemistry and exploration methods: Myra Falls volcanogenic massive-sulphide deposits, Vancouver Island, British Columbia, Canada
Authors: Phipps Graham C. , Boyle D.R. , Clark I.D.
Published: March 2005

The Myra Falls Price deposit is a zinc-rich volcanogenic massive-sulphide ore-body located in a mountainous region of central Vancouver Island, British Columbia. High rainfall and steep hydraulic gradients limit the water–mineral contact, which results in a low solute load in the oxygenated groundwater. Despite this, significant element contrasts exist that permit the development of groundwater geochemical methods for exploration. Zinc displays the strongest and most reliable anomaly contrasts in groundwaters associated with mineralization related to the Price deposit. Statistical procedures are used to differentiate two overlapping subpopulations of Zn concentrations, which are partitioned into two constituent populations. A threshold value of 20 μg/l was established, which includes an uncertainty that allows up to 10% of the background population being defined as anomalous. Zn anomalies can be further enhanced with a suite of pathfinder elements associated with primary mineralization and hydrothermal alteration, including Cu, Pb, Cd, Mn, As, Sb, Ba and U.

In addition to massive-sulphide mineralization, sulphides also exist as clasts within a breccia unit designated as the ore-clast breccia (OCB). Effective discrimination is possible between anomalies in groundwaters associated with massive-sulphide mineralization and groundwaters associated with OCB through the use of elements associated with primary mineralization and hydrothermal alteration such as K, Rb, B, Ba, Cd, Sb, U and barite saturation, which are elevated in groundwaters associated with massive-sulphide mineralization but not the OCB.

Groundwater geochemical exploration methods offer a supplemental tool to exploration of Zn-rich massive-sulphide deposits where existing infrastructure, exploration drifts and drill holes are present.
Galvanic sulphide oxidation as a metal-leaching mechanism and its environmental implications
Authors: Kwong Y.T. John , Swerhone George W. , Lawrence John R.
Published: March 2005

Following a brief review of the theoretical aspects of galvanic sulphide oxidation, the significance of galvanic interaction in the oxidation of natural mixed sulphide assemblages is demonstrated using test materials prepared from sulphide-containing rocks in a series of chemical and microbial weathering experiments. The test results indicate that: (1) metal leaching can effectively proceed even in a near-neutral environment; and (2) the occurrence of acid mine drainage can be delayed due to cathodic protection of an acid-generating sulphide such as pyrite from oxidative dissolution. While microbial mediation may enhance the weathering of sulphides with a high electrode potential, the competing galvanic processes diminish the dominating role of the microbes in effecting the oxidation of sulphides with a low electrode potential when the sulphides occur in a mixed assemblage.
In-situ
potential measurements on sulphide surfaces with micro-electrodes demonstrated the occurrence of a significant potential difference between a contacting sulphide pair sufficient to sustain galvanic interaction for the duration of the experiments. It is also shown that galvanic sulphide oxidation and hence metal leaching can occur even under an oxygenated water cover. Therefore, subaqueous disposal may not be the best management option for all reactive mine wastes, especially those containing metals or trace elements that remain mobile under near-neutral pH conditions.
Stable isotope (C, O, S) systematics in alteration haloes associatedwith orogenic gold mineralization in the Victorian gold province,SE Australia
Authors: Bierlein Frank P. , Arne Dennis C. , Cartwright Ian
Published: March 2005

This study investigates whether hydrothermal alteration of metasedimentary rocks associated with orogenic gold mineralization in the Victorian gold province produces systematic changes in oxygen, carbon and sulphur isotope compositions that might provide explorationists with vectors towards ore. The presence of systematic isotopic trends across wallrock alteration haloes in gold deposits in the Stawell, Percydale, Ballarat, Bendigo and Fosterville goldfields clearly supports the interpreted hydrothermal origin of these haloes. General increases in carbonate δ
13
C towards the ore zones in all deposits record the influx of hydrothermal CO
2
. Whole-rock silicate and quartz δ
18
O, carbonate δ
18
O, and sulphide δ
34
S shifts equally mirror petrological and geochemical changes that resulted from prolonged and extensive interaction between externally derived hydrothermal fluids and the surrounding siliciclastic wallrocks. With the possible exception of sulphur, however, the isotopic enrichment/depletion trends are subtle and also vary significantly from deposit to deposit. Results of this study and comparisons with published data suggest that the oxygen and carbon isotopic ratios of silicates and carbonates in whole-rock samples within the alteration haloes are buffered by the wallrocks. Hydrothermal sulphides in Victorian orogenic gold deposits are characterized by δ
34
S values generally in the range −5 to +5‰. However, there is relatively little influx of hydrothermal sulphur beyond
c.
5 to 10 m from the vein margins and disseminated pyrite well removed from the lode systems is characterized by either greatly negative or positive δ
34
S values typically greater than±10‰.
Rare earth element geochemistry of groundwater in the Palouse Basin, northern Idaho–eastern Washington
Authors: Nelson Bethany J. , Wood Scott A. , Osiensky James L.
Published: March 2005

Concentrations of rare earth elements (REE) were determined in groundwaters from the Palouse Basin, located in northern Idaho and eastern Washington. Samples were taken from wells and springs tapping waters in four different rock units: loess, Wanapum Basalt, Grande Ronde Basalt, and Moscow Mountain Granite. In general, unfiltered aliquots of the waters had higher concentrations of REE than those filtered through a 0.45 μm filter, sometimes by several orders of magnitude, indicating the presence of REE as suspended particles or large colloids. Overall REE concentrations in the waters decrease, and the unfiltered and filtered aliquots become more similar in concentration, with increasing depth within the stratigraphic section (i.e. loess → Wanapum → Grande Ronde). There are some distinctions in NASC (North American Shale Composite)-normalized REE patterns among the four groups of waters, but there is considerable variation among the waters within each group. When normalized to their host rocks, most filtered and many unfiltered aliquots of groundwaters from all four units show depletion of the LREE relative to the HREE. The results are consistent with a model in which meteoric water enters the basalt aquifers via the loess, picking up a heavy particulate and some dissolved REE load, followed by infiltration downward through the units. While moving downwards, the waters are subjected to natural filtration processes in which the particulate REE are largely removed.
High thallium content in rocks associated with Au–As–Hg–Tl and coal mineralization and its adverse environmental potential in SW Guizhou, China
Authors: Xiao Tangfu , Guha Jayanta , Boyle Dan
Published: March 2005

Very few investigations have dealt with the environmental impact of the highly toxic metal thallium (Tl), and its subsequent dispersion through natural processes and human activities such as mining and farming. This study is focused on high concentrations of Tl in rocks in SW Guizhou, China, that are related to several widely scattered disseminated gold–mercury–arsenic and coal deposits, and a primary Tl deposit within an Au–As–Hg–Tl metallogenic belt of the Huijiabao anticline. The Tl, Hg and As in the Lanmuchang Hg–Tl deposit area are associated with the abundant occurrence of sulfide minerals such as lorandite, realgar, orpiment and cinnabar. Concentrations of Tl range from 100 to 35 000 ppm in sulfide ores, and 39–490 ppm in host rocks. The enrichment of Au, Tl, Hg, As, and Sb in the Yanshang gold mineralized area reflects the occurrence of Au mineralization and its mineral assemblage of Tl–Hg–As–Sb sulfides. Thallium ranges from 0.22 to 16 ppm in Au ores and host rocks. Thallium in coals is enriched up to 46 ppm within the Au–As–Hg–Tl metallogenic belt, and is derived from the regional Au–As–Hg–Tl mineralization. Mercury and As show a similar distribution to Tl with high concentrations in sulfide ores, coals and host rocks.

Human populations living near and downstream of Tl deposits and Tl-bearing ore deposits are susceptible to Tl contamination because of its high toxicity and high uptake rate by crops. The dispersion of Tl, Hg and As associated with the primary mineralization of Au–As–Hg–Tl can be traced through physical erosion and chemical weathering, producing secondary dispersion into soils, groundwater and surface water and crops. Mining activities compound the natural processes, readily dispersing Tl into the surface environment. The Lanmuchang area illustrates Tl contamination related to a Tl-rich deposit due to both natural processes and the impact of mining. The Yanshang area demonstrates Tl contamination related toa Tl-bearing gold deposit, caused by natural processes in the absence of mining activity.
Interaction of aqueous Au species with goethite, smectite and kaolinite
Authors: Cohen D.R. , Waite T.D.
Published: March 2005

Adsorption of aqueous Au species by goethite, smectite and kaolinite has been investigated as a function of pH at 25 °C. Adsorption isotherms indicate Au is mainly adsorbed as anionic complexes with adsorption edges centred at pH 8.5 for goethite, 7.5 for smectite (Swy-1) and 8.0 for kaolinite (KGa-1). The possibility that colloidal Au species interact with the mineral surfaces cannot be excluded. A zone of slow adsorption of Au(III) complexes exists for goethite at pH <6.5 and kaolinite at pH <8, with complete adsorption from solutions containing <5 μM Au and 1 g/l solids requiring over 100 hours of reaction time. Adsorption by goethite in thepH range 7–9 is more rapid and may be largely attributed to adsorption of Au(OH)
3
.(H
2
O)
o
. The loss of Au from solution at pH values above adsorption edges may be due to adsorption of uncharged Au species or development of colloidal gold. Aqueous phase equilibrium modelling indicates Au
o
(monomer or colloid) to be the dominant phase at pH 4–10 but its rate of formation in 0.1 M NaCl is slow. The uptake of Au by goethite has been modelled as an inner-sphere surface complexation using the diffuse layer model. The model of best fit was obtained using a single binding site and setting AuCl
4
−
, AuCl
3
(OH)
−
and Au(OH)
3
.(H
2
O)
o
as the main Au(III) sorbing species with logK
int
values for the formation of the adsorbed species of 9, 35 and 17 respectively.
Soil data analysis from central Portugal by Principal Component Analysis and geostatistical techniques
Authors: Batista A. C. , Ferreira da Silva E. A. , Azevedo M. C. C. , Sousa A. J. , Cardoso Fonseca E.
Published: March 2005

The area under study is located near Estarreja, in central Portugal where chemical industries are the main source of pollution. Until 1975, liquid effluents produced by these industrial units were discharged directly into several nearby streams. These effluents contained many different types of contaminants, such as aniline, benzene, monochlorobenzene, mononitrobenzene, As, Hg, Zn and Pb, amongst others. The industrial units also dumped a large amount of solid waste, which was stockpiled, directly on the surrounding land. This solid waste contains pyrite-rich ashes, dusts and sludge containing Hg and calcium hydroxide. A geochemical soil survey was conducted in a 49-km
2
area where a total of 985 soil samples were collected during 1998 and 1999, on a regular grid of 200 × 200 m. The soil samples were analysed for Cu, Pb, Zn, Fe, Mn, Co, Ni, Cr and As, following an HCl–HNO
3
–HF digestion.

To identify the main soil contaminants and to map the most important contaminated areas, Principal Component Analysis (PCA) and geostatistical techniques (Variography and Kriging map) were used. The results of PCA data analysis, compared to the available information in pollution indices (Contamination Index – Cidx), outline one important area contaminated by Cu, Pb, Zn and As as a result of effluent dumping by the chemical industry.
Sulphide oxidation and groundwater transport of base metals at the Halfmile Lake and Restigouche Zn–Pb massive sulphide deposits, Bathurst Mining Camp, New Brunswick
Authors: Leybourne Matthew I. , Goodfellow Wayne D. , Boyle Dan R.
Published: March 2005

A detailed hydrogeochemical study at the undisturbed Halfmile Lake and Restigouche Zn–Pb deposits, Bathurst Mining Camp, New Brunswick, was initiated to elucidate processes controlling the oxidation of sulphide minerals, factors influencing base-metal dispersion in ground and surface waters, and to improve hydrogeochemical exploration methods. Groundwaters were collected using flow-through bailer and straddle-packer technologies; the latter of which proved to be the most effective under the fracture-flow dominated conditions. Groundwaters from the two deposits are compositionally distinct. At the Halfmile Lake deposit, groundwaters are dominated by low total dissolved solids (TDS < 250 mg l
−1
) and Ca–HCO
3
-type compositions. Groundwaters at the Restigouche deposit vary in composition from shallow Ca–HCO
3
- and Ca–SO
4
-type waters to high TDS Na–Cl-type waters. Elevated sulphate and base metal contents (up to 4200 μg l
−1
Zn and 1400 μg l
−1
Pb) of shallow Ca–SO
4
-type groundwaters proximal to massive sulphides indicate that the sulphides are undergoing natural oxidation. The degree to which the massive sulphides are oxidized depends on the depth of penetration of dissolved oxygen and flux rates, which are controlled by the permeability of the rocks and local hydrological gradients. Transport of metals away from massive sulphides depends on physical factors that include hydrology, groundwater flow, and the degree of connectivity between groundwater and surface water environments, as well as groundwater pH, metal adsorption and colloid mobility.
Application of the artificial neural network to multivariate anomalyrecognition in geochemical exploration for hydrocarbons
Authors: Zhang Liuping , Bai Guoping
Published: March 2005

Traditional methods of multivariate statistical analyses, used to recognize anomalous hydrocarbon signatures in petroleum exploration, have at least four shortcomings: (1) it is difficult to isolate anomalies where the data are not normally distributed; (2) it is difficult to separate distinct anomaly populations corresponding to distinct formation mechanisms while separating anomalies from background; (3) it is not fitting to present illustrations of multivariate anomalies on contour maps; and (4) it is not suitable for preparation for multivariate pattern recognition. These present serious obstacles to the application of exploration geochemistry in hydrocarbon exploration. This study demonstrates that the Back Propagation Artificial Neural Network (BP-ANN) with logic multiplication cluster analysis (a new cluster analysis proposed in this paper) overcomes the difficulties exhibited by traditional multivariate methods. The logic multiplication cluster analysis was designed to produce a training set for the BP-ANN. This approach was established on the basis of geochemical characteristics and origin of the various populations in geochemical data, such as background, micro-seepage anomalies and seepage anomalies. The topology of the BP-ANN was optimized using the outputs of the BP-ANN and the correct rate. In order to illustrate the multivariate anomalies recognized using BP-ANN on contour maps, we designed the expression functions for BP-ANN application in this field. With traditional methods of anomaly recognition, acid-extractable hydrocarbons in soils have not proven to be efficient indicators for hydrocarbon potential in East Anan Sag, Inner Mongolia. However, the BP-ANN has indicated that these indicators are efficient and that areas of East Anan Sag have potential reserves of petroleum.
MINSQ – a least squares spreadsheet method for calculating mineral proportions from whole rock major element analyses
Authors: Herrmann Walter , Berry Ron F.
Published: March 2005

MINSQ is a spreadsheet adaptation of the least squares method that utilizes the
Solver
tool in Microsoft Excel™ to quantitatively estimate the proportions of constituent minerals in rocks from whole rock lithogeochemical data. It is simple to use and easily and interactively adaptable to observed mineral or normative assemblages. The structure facilitates input of actual mineral analyses for individual rock samples. The spreadsheet format and the numerical
Solver
tool in Microsoft Excel™ put the user in a powerful position to adapt this method to a wide range of numerical problems in geochemistry.
Regolith mineralogy and geochemical dispersion at the Northparkes Cu–Au deposits, New South Wales, Australia
Authors: Tonui Eric , Jones Roger , Scott Keith
Published: March 2005

The Cu–Au mineralization at Northparkes, western NSW, Australia, occurs as disseminated or veined sulphides in K-rich trachyandesites intruded by quartz monzonite porphyries. Detailed mapping of the open pits revealed a complex regolith consisting of in situ weathered mineralized trachyandesite and weathered alluvial–colluvial material in a palaeovalley. The kaolinite–smectite-rich sediments have been locally derived, and are marked by development of mottles and ferruginous nodules indicating intense post-depositional weathering. Primary mineralization is expressed in the regolith by anomalous Au, Cu and As contents. Lead and Zn show variable dispersion patterns in the transported regolith of the E22 and E27 deposits. This is probably due to differences in their chemical mobility, provenance and sedimentary environment. Although it occurs at depth (30–50 m), the widespread occurrence of saprock makes it a very good sampling medium in this region.