bluuebunny/crossref_metadata_2025 huggingface dataset:
KPC Screening by Updated BD Phoenix and Vitek 2 Automated Systems
Authors: Thomson Kenneth S. , Robledo Iraida E. , Vázquez Guillermo J. , Moland Ellen S.
Published: July 2011

Current BD Phoenix and Vitek 2 methodologies were assessed as screens for KPC β-lactamases. Using carbapenem MICs or expert system interpretations as screens, both systems exhibited high (97%) sensitivity in tests with 103 well-characterized Gram-negative isolates, 77 of which were KPC producers.
High Concordance between the Position-Specific Scoring Matrix and Geno2pheno Algorithms for Genotypic Interpretation of HIV-1 Tropism: V3 Length as the Major Cause of Disagreement
Authors: Seclén Eduardo , Soriano Vicente , González María M. , Gómez Sagrario , Thielen Alexander , Poveda Eva
Published: July 2011

The agreement between the position-specific scoring matrix (PSSM) and geno2pheno as tools for genotypic interpretation of HIV-1 tropism using 800 clinical specimens was assessed. There was an overall concordance of 88%. Disagreement was found mostly in specimens with short V3 lengths (<35 amino acids). Thus, consideration of V3 lengths should improve the predictability of HIV-1 tropism using genotypic algorithms.
Infections Caused by Unusual Methylobacterium Species
Authors: Lai Chih-Cheng , Cheng Aristine , Liu Wei-Lun , Tan Che-Kim , Huang Yu-Tsung , Chung Kuei-Pin , Lee Meng-Rui , Hsueh Po-Ren
Published: July 2011

We describe six patients with hospital-acquired bacteremia caused by
Methylobacterium
species, including
M. radiotolerans
(
n
= 2),
M. thiocyanatum
(
n
= 2),
M. aminovorans
(
n
= 1), and
M. lusitanum
(
n
= 1), which were confirmed to species level by 16S rRNA gene sequence analysis. Among these patients, five had catheter-related bacteremia and all had favorable outcomes.
Functional Genomics Reveals the Induction of Inflammatory Response and Metalloproteinase Gene Expression during Lethal Ebola Virus Infection
Authors: Cilloniz Cristian , Ebihara Hideki , Ni Chester , Neumann Gabriele , Korth Marcus J. , Kelly Sara M. , Kawaoka Yoshihiro , Feldmann Heinz , Katze Michael G.
Published: July 2011

Ebola virus is the etiologic agent of a lethal hemorrhagic fever in humans and nonhuman primates with mortality rates of up to 90%. Previous studies with Zaire Ebola virus (ZEBOV), mouse-adapted virus (MA-ZEBOV), and mutant viruses (ZEBOV-NP
ma
, ZEBOV-VP24
ma
, and ZEBOV-NP/VP24
ma
) allowed us to identify the mutations in viral protein 24 (VP24) and nucleoprotein (NP) responsible for acquisition of high virulence in mice. To elucidate specific molecular signatures associated with lethality, we compared global gene expression profiles in spleen samples from mice infected with these viruses and performed an extensive functional analysis. Our analysis showed that the lethal viruses (MA-ZEBOV and ZEBOV-NP/VP24
ma
) elicited a strong expression of genes 72 h after infection. In addition, we found that although the host transcriptional response to ZEBOV-VP24
ma
was nearly the same as that to ZEBOV-NP/VP24
ma
, the contribution of a mutation in the NP gene was required for a lethal phenotype. Further analysis indicated that one of the most relevant biological functions differentially regulated by the lethal viruses was the inflammatory response, as was the induction of specific metalloproteinases, which were present in our newly identify functional network that was associated with Ebola virus lethality. Our results suggest that this dysregulated proinflammatory response increased the severity of disease. Consequently, the newly discovered molecular signature could be used as the starting point for the development of new drugs and therapeutics. To our knowledge, this is the first study that clearly defines unique molecular signatures associated with Ebola virus lethality.
Herpes Simplex Virus 1 Protein Kinase Us3 and Major Tegument Protein UL47 Reciprocally Regulate Their Subcellular Localization in Infected Cells
Authors: Kato Akihisa , Liu Zhuoming , Minowa Atsuko , Imai Takahiko , Tanaka Michiko , Sugimoto Ken , Nishiyama Yukihiro , Arii Jun , Kawaguchi Yasushi
Published: July 2011

Us3 is a serine-threonine protein kinase encoded by herpes simplex virus 1 (HSV-1). We have identified UL47, a major virion protein, as a novel physiological substrate of Us3.
In vitro
kinase assays and systematic analysis of mutations at putative Us3 phosphorylation sites near the nuclear localization signal of UL47 showed that serine at residue 77 (Ser-77) was required for Us3 phosphorylation of UL47. Replacement of UL47 Ser-77 by alanine produced aberrant accumulation of UL47 at the nuclear rim and impaired the nuclear localization of UL47 in a significant fraction of infected cells. The same defect in UL47 localization was produced by an amino acid substitution in Us3 that inactivated its protein kinase activity. In contrast, a phosphomimetic mutation at UL47 Ser-77 restored wild-type nuclear localization. The UL47 S77A mutation also reduced viral replication in the mouse cornea and the development of herpes stromal keratitis in mice. In addition, UL47 formed a stable complex with Us3 in infected cells, and nuclear localization of Us3 was significantly impaired in the absence of UL47. These results suggested that Us3 phosphorylation of UL47 Ser-77 promoted the nuclear localization of UL47 in cell cultures and played a critical role in viral replication and pathogenesis
in vivo
. Furthermore, UL47 appeared to be required for efficient nuclear localization of Us3 in infected cells. Therefore, Us3 protein kinase and its substrate UL47 demonstrated a unique regulatory feature in that they reciprocally regulated their subcellular localization in infected cells.
When does a fetus become a person? An Israeli viewpoint
Authors: Rimon-Zarfaty Nitzan , Raz Aviad E , Hashiloni-Dolev Yael
Published: July 2011

Background and methodology

‘Biological’ and ‘human’ life or ‘personhood’ are not necessarily identical. While the Catholic Church does not separate the two, concluding that human life commences at conception, Judaism endows the fetus with personhood gradually throughout the pregnancy. Gradualism is also reflected in many Western abortion laws that prohibit ‘late abortion’. Importantly, the Israeli law does not prohibit abortion at any stage of pregnancy. To examine attitudes regarding the status of the fetus vis-a-vis its stages of development, a questionnaire presenting ten successive stages was distributed to Israeli respondents (n = 281). For each stage participants were asked to grade the fetus as having ‘personhood’ or as a ‘living organism’ on a five-point scale. Data were analysed to show frequency distribution.

Results

The fetus gains its ascribed personhood gradually. Most of the participants perceived the fetus as a person at the stage in which the woman feels its movements. Additionally, many (especially secular respondents) evaluated the fetus as a living organism at earlier stages, thus making a distinction between the fetus as a living organism and as a person. An international comparison with English-speaking countries revealed a local ‘Israeli’ tendency to attribute personhood status to the fetus only at a relatively late stage.

Discussion and conclusions

The ‘Israeli’ fetus acquires its status gradually. This finding challenges the dichotomous conceptualisation of the fetus as ‘a person’ or ‘non-person’. The authors conclude by presenting the perceived transformation of the fetus to ‘personhood’ as being influenced by national and religious factors.
Academic freedom and global health
Authors: Evans Donald
Published: July 2011

There is a tension between the preservation of academic freedom and the economic context in which the university currently finds itself. This tension embodies serious threats to global health as a result of three overlapping phenomena which impede the production and diffusion of valuable knowledge about health. These phenomena, the privatisation, commercialisation and instrumentalisation of knowledge are identified and examined in this paper in relation to human rights and international morality.
Outcome in small aneurysms (<4 mm) treated by endovascular coiling
Authors: Lum Cheemun , Narayanam Surendra Babu , Silva Leonardo , Shankar Jai , Bussiere Miguel , Dos Santos Marlise P , Lesiuk Howard
Published: July 2011

Background

Coiling of small aneurysms can be technically challenging. These aspects of coiling tend to be less problematic in medium to large aneurysms as they are more accommodating of microcatheters and coils. When physicians are asked their opinion regarding aneurysm coilability in small aneurysms, the decision often lies in the operator's feeling that they could reasonably exclude the aneurysm with a complication rate similar to larger aneurysms. The purpose of our study was to investigate the feasibility, intraprocedural rupture rates and long term durability of endovascular coiling for small (≤4 mm) aneurysms compared with non-small (>4 mm) aneurysms. To control for factors such as vessel tortuosity and aneurysm location, a control group was chosen matched to the study group both in age and aneurysm location.

Materials and methods

A retrospective review of 360 intracranial aneurysms coiled at our institution between 2003 and 2008 was performed. For the control group, intracranial aneurysms coiled in the same period matched to location and age were chosen.

Results

The frequency of intraprocedural perforations was 4/34 (0.12) and 3/68 (0.04) for the small and non-small cohort, respectively (p=0.22). All patients who had a perforation in the small aneurysm groups had a good clinical outcome compared with 1/3 in the non-small group (two mortalities). The frequency of recanalization for the small and non-small groups was 3/34 (0.09) and 23/68 (0.33), respectively (p=0.006). There was no retreatments in the small aneurysm group and five (0.07) in the non-small group (p=0.116).

Conclusion

Coiling of small (≤4 mm) aneurysms is feasible with a reasonable complication rate. There is a non-significant increase in frequency of intraprocedural rupture with coiling of small aneurysms compared with controls matched to aneurysm location and age but this is not associated with increased morbidity. Coiling of small aneurysms leads to durable results at long term follow-up.
Local differentiation of flowering phenology in an alpine-snowbed herb Gentiana nipponica
Authors: Kawai Yuka , Kudo Gaku
Published: July 2011

Phenological events of alpine plants are strongly influenced by the seasonal thermal conditions at the local scale that are caused by heterogeneity in snowmelt time. Populations in late-snowmelt locations suffer from a short period for seed maturation, in which rapid flowering that occurs soon after snowmelt (i.e., a low thermal requirement for flowering) is advantageous. To test the possibility of local adaptation of flowering phenology, we compared reproductive phenology, the preflowering period, and the thermal requirement for flowering of the alpine-snowbed species Gentiana nipponica Maxim. between populations inhabiting early- and late-snowmelt sites within a local area. Plants in the late-snowmelt population showed a shorter preflowering period than in the early-snowmelt population; nevertheless, they often failed to set fruit owing to the short growth period. To test the plasticity and genetic regulation of flowering phenology, we performed a reciprocal transplant experiment between early- and late-snowmelt populations. Although the preflowering period showed clear plastic responses depending on the transplanted habitats, the lower thermal requirement for flowering was retained in plants originating from the late-snowmelt populations, even after transplantation. Therefore, habitat-specific differentiation of flowering phenology was genetically determined between these local populations.
Polymerase chain reaction identification of a female-specific genetic marker inArceuthobium americanum(lodgepole pine dwarf mistletoe) and its implications forArceuthobiumsex determination
Authors: Dwarka Arvin , Ross Friedman Cynthia M. , MacKay Mairi E. , Nelson Don
Published: July 2011

In North America, the most widespread and speciose mistletoe is Arceuthobium M. Bieb. (dwarf mistletoes, Viscaceae), which is a dioecious parasite of conifers. Little is known about its sex determination system, and sex chromosomes have not been identified. A genetic marker for early gender discrimination in Arceuthobium would be useful in the study of sex ratios and sex determination. Here, random amplified polymorphic DNA analysis via the polymerase chain reaction (PCR) was used to investigate genetic differences between genders in Arceuthobium americanum Nutt. ex Engelm. collected near Kamloops, British Columbia and Bélair, Manitoba. A total of 196 10-mer primers were selected for analysis of DNA from isolated male and female A. americanum somatic tissue. A ∼900 bp female-specific DNA fragment was generated with primer OPB-18 (5′-CCACAGCAGT-3′). The fragment was cloned and sequenced. Using GenBank and the basic local alignment search tool alignment software, it was determined that the first ∼300 bp of this DNA sequence shared a high degree of similarity to transposable elements (76%) and a Y-chromosome (male) fragment (75%) in Silene latifolia Poir. Sequence-characterized amplified region primers were then designed. This study has generated an efficient molecular tool to differentiate male and female A. americanum while also providing evidence indicating that A. americanum may have homomorphic, possibly protoheteromorphic, sex chromosomes.
Uptake and partitioning of simulated atmospheric N inputs inPopulus tremuloides – Pinus strobusforest mesocosms
Authors: Nave Lucas E. , Curtis Peter S.
Published: July 2011

Canopies of forest ecosystems frequently intercept and retain >50% of atmospheric nitrogen (N) deposition. Atmospheric N reaching the forest floor often is retained in litter and soil pools, but if atmospheric N retained by the canopy is assimilated through foliar uptake, then N inputs may have greater effects on tree N requirements and growth than suggested by N additions to forest floors alone. To quantify foliar and root uptake of N deposition by trees and to determine patterns of within-tree N allocation, we performed a tightly controlled15N tracer experiment using constructed, seminatural forest mesocosms. Mesocosms contained seedling trees, which assimilated modest amounts of the aqueous15NH4Cl applied to their canopies and surrounding soils (10% and 14%, respectively). The seedlings allocated most of the15N that they took up to leaf biomass (40%–50%), regardless of uptake pathway. Soil pools retained >80% of the15N applied to mesocosm forest floors, with soil organic matter concentration explaining 79% of the variation in soil15N recovery across sampling depths. The low value for15N movement into biomass and its retention in soil pools suggests that atmospheric N deposition measured at a nearby forest site has no short-term effects on tree N content or growth.
Influence of arbuscular mycorrhizae on biomass and root morphology of selected strawberry cultivars under salt stress
Authors: Fan Li , Dalpé Yolande , Fang Chengquan , Dubé Claudine , Khanizadeh Shahrokh
Published: July 2011

To investigate the influence of arbuscular mycorrhizal fungi (AMF) on biomass and root morphology, a greenhouse experiment was conducted using three elite strawberry ( Fragaria  × ananassa Duch.) cultivars (‘Kent’, ‘Jewel’, and ‘Saint-Pierre’). They were subjected to three NaCl levels (0, 30, and 60 mmol/L) and were inoculated and noninoculated (control) with AMF Glomus irregulare . The presence of AMF significantly changed root morphology and increased root-length percentages of medium (0.5 mm < root diameter φ ≤ 1.5 mm) and coarse (φ > 1.5 mm) roots, shoot and root tissue biomass, root to shoot ratio (R/S ratio), and specific root length (SRL), regardless of cultivar and salinity. In contrast, salt alone changed root morphology and decreased shoot and root tissue biomass, R/S ratio, and SRL. The AMF colonization rates were reduced linearly and significantly with increasing salinity levels. Cultivars responded differently to AMF than to salt stress. ‘Saint-Pierre’ seemed to be the most tolerant cultivar to salinity, while ‘Kent’ was the most sensitive. Consequently, AMF symbiosis highly enhanced salt tolerance of strawberry plants, which confirmed the potential use of mycorrhizal biotechnology in sustainable horticulture in arid areas.
Changes in cytosine methylation and DNA sequence induced by ethylmethane sulfonate in rice
Authors: Wang Xiaoli , Ou Xiufang , Wang Kaixi , Dong Mingyue , Man Guiliang , Cai Yi , Shi Yu , Yu Xiaoming , Liu Bao
Published: July 2011

Although genetic mutagenicity of the chemical ethylmethane sulfonate (EMS) is well established, it remains unclear whether and to what extent this compound is epigenetically mutagenic. This issue was studied in Oryza sativa L. (rice) by conducting a parallel investigation using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), on two sets of EMS-treated M0 plants: phenotypically normal and altered. Although more methylation than genetic changes were induced by the EMS-treatments in both sets of plants, the greatest differences were observed in the set of plants with altered phenotypes, suggesting a role of induced epigenetic variation in causing the phenotypic novelties. Moreover, the frequencies of the two types of instabilities induced by the EMS treatment, genetic and epigenetic, are correlated, implicating a common or overlapping mutagenic basis.
Seismic reflection constraints on upper crustal structures in the volcanic-covered central Nechako basin, British Columbia1This 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: Calvert A.J. , Hayward N.E. , Spratt J.E. , Craven J.A.
Published: July 2011

In 2008, a Vibroseis seismic reflection survey was acquired by Geoscience BC across the eastern part of the volcanic-covered Nechako basin in central British Columbia, where Cretaceous sedimentary rocks have been exhumed along a NNW trend. Good signal penetration through the volcanic cover is indicated by lower crustal reflections at 8–12 s, which were recorded by the entire seismic survey. Comparison of the 2008 seismic survey with data from a previous survey indicates that the lack of reflectivity in the earlier surveys is generally representative of the subsurface geology. The seismic data show that ∼1700 and ∼2900 m thick sub-basins are present at the northern and southern ends of this trend, but the intervening Cretaceous rocks are discontinuous and relatively thin. The creation of a passive-roof duplex by Campanian or later low-angle thrusting is inferred within the thickest Cretaceous strata, but elsewhere faulting is likely related to Eocene extension or transtension. Seismic reflections are also recorded from folded volcanic stratigraphy, the base of the surface volcanic rocks, an underlying volcaniclastic stratigraphy, and intrusions projecting into a Quaternary volcanic cone. Seismic interpretation is complemented by coincident audiofrequency magnetotelluric surveys, from which faulting is inferred at offsets in a regional conductor. No regionally extensive stratigraphy can be identified within the seismic data, and the central Nechako basin appears to be a complex network of small, deformed sub-basins, rather than a single large basin.
Late Wisconsinan glacial history in the Bonaparte Lake map area, south-central British Columbia: implications for glacial transport and mineral exploration1This 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.2Earth Sciences Sector Contribution Number: 20100093.
Authors: Plouffe A. , Bednarski J.M. , Huscroft C.A. , Anderson R.G. , McCuaig S.J.
Published: July 2011

This study is centred on the Bonaparte Lake map area located in the southern Interior Plateau of south-central British Columbia. The reconstruction of the Late Wisconsinan glacial history of this part of the southern sector of the Cordilleran Ice Sheet incorporates (i) the analysis and interpretation of landforms of various scales, (ii) the sedimentology and stratigraphy of glacial sediments, and (iii) the geochemical and mineralogical composition of till and analysis of regional glacial dispersal of these components. The onset of the last glacial event was initiated by ice advancing westerly and southwesterly into the study area from an alpine source region located in the Cariboo Mountains. As glaciation intensified, ice from the Coast Mountains coalesced with the Cariboo Mountain ice over the Interior Plateau and developed into an ice divide around 52° north latitude, which resulted in ice flow to be diverted to a southerly direction over the study area. The two dominant ice-flow directions produced palimpsest dispersal that was measured by three tracers in till including thorianite grains and terbium concentrations in the heavy mineral fraction, and granitoid pebble percentage. The two main phases of ice flow identified within our study area have significant implications for mineral exploration that uses mineral tracing in glacial sediments, especially in the area underlain by the highly prospective Quesnel Terrane.
Investigation of a ship's propeller jet using momentum decay and energy decay
Authors: Lam Wei-Haur , Song Yongchen , Raghunathan Srinivasan , Hamill Gerard , Robinson Desmond
Published: July 2011

Previous researchers use the velocity decay as an input to investigate the ship’s propeller jet induced scour. A researcher indicated that most of the equations used to predict the stability of various protection systems are often missing a physical background. The momentum decay and energy decay are currently proposed as an initial input for seabed scouring investigation, which are more sensible in physics. Computational fluid dynamics (CFD) and laser Doppler anemometry (LDA) experiments are used to obtain the velocity data and then transforming into momentum and energy decays. The findings proposed several exponential equations of velocity, momentum and energy decays to estimate the region exposed to the seabed scouring.
Influence of suspended and off-bottom mussel culture on the sea bottom and benthic habitats: a review1This review is part of a virtual symposium on current topics in aquaculture of marine fish and shellfish.
Authors: McKindsey Christopher W. , Archambault Philippe , Callier Myriam D. , Olivier Frédéric
Published: July 2011

Aquaculture is the fastest growing sector of the food industry, raising concerns about the influence of this activity on the environment. We take a holistic approach to review off-bottom and suspended mussel culture effects on the benthic environment and benthic communities. Both longline and “bouchot” mussel culture add much physical structure (infrastructure and mussels) to the environment, altering hydrosedimentary processes by modifying currents and increasing sedimentation locally, and providing habitat for many benthic organisms. Biodeposition from mussels and these organisms increases benthic organic loading and linked biogeochemical processes to influence O2, pH, redox potentials, dissolved sulphides, and other sediment parameters, benthic respiration and nutrient fluxes, and benthic infaunal communities. Mussel culture may also influence seagrasses and algae, although this has not been well-studied. Far-field effects on the benthos may occur through a number of mechanisms, including aggregation of epibenthic macrofauna in culture sites, alteration of plankton communities, and the enhancement of exotic and indigenous pest species owing to the addition of physical structure to the environment. Quantitative relationships between farming level and benthic influences are lacking, making predictions of effects difficult.
Production of flounder (Pleuronectiformes) in eastern North America: biological issues1This review is part of a virtual symposium on current topics in aquaculture of marine fish and shellfish.
Authors: Audet C. , Tremblay R.
Published: July 2011

Flounders (Pleuronectiformes) from eastern North America have been extensively studied over the last few decades, and most of that work has been oriented towards different aspects related to fish production, i.e., aquaculture. However, aquaculture production has not progressed as it might have been expected. Flounders are omnivorous, euryhaline, inhabit shore habitats, and offer good potential for aquaculture diversification. They are found all along the eastern coast of Canada and the US, and different species occupy coastal habitats with some species overlapping in certain areas. Despite specific biological and ecological requirements for each species, the accumulated knowledge on breeding, larval rearing, juveniles, and stock enhancement creates a frame of reference that is often underestimated but that indicates a promising future for the production of these fishes.
D MESON HADRONIC DECAYS AT CLEO-c
Authors: YANG FAN
Published: July 2011

The recent CLEO-c results on hadronic decays of D and Ds mesons are presented. First the absolute branching fractions for D and Ds mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.
A MONOPOLE INSTANTON-LIKE EFFECT IN THE ABJM MODEL
Authors: NAGHDI M.
Published: July 2011

Making use of ansatzs for the form fields in the ten-dimensional type IIA supergravity version of the ABJM model, we come with a solution in the Euclidean signature recognized as a monopole instanton-like object. Indeed we will see that we can have a (anti-)self-dual solution at a special limit. While as a topological object, its backreaction on the original background should be ignorable, we show the energy–momentum tensors vanish exactly. On the field theory side, the best counterpart is an U(1) gauge field of a gauge transformation. To adjust with bulk, the gauge field must prompt to a dynamic one without adding any kinetic term for this dual photon except a marginal, Abelian AB-type Chern–Simons term on the boundary. We will see how both side solutions match next to another confirmation from some earlier works of this vortex–particle duality.
EQUILIBRIUM POINTS AND THEIR STABILITY IN THE RESTRICTED FOUR-BODY PROBLEM
Authors: BALTAGIANNIS A. N. , PAPADAKIS K. E.
Published: July 2011

We study numerically the problem of four bodies, three of which are finite, moving in circles around their center of mass fixed at the origin of the coordinate system, according to the solution of Lagrange where they are always at the vertices of an equilateral triangle, while the fourth is infinitesimal. The fourth body does not affect the motion of the three bodies (primaries). The allowed regions of motion as determined by the zero-velocity surface and corresponding equipotential curves as well as the positions of the equilibrium points are given. The existence and the number of collinear and noncollinear equilibrium points of the problem depend on the mass parameters of the primaries. For three unequal masses, collinear equilibrium solutions do not exist. Critical masses associated with the existence and the number of equilibrium points, are given. The stability of the relative equilibrium solutions in all cases is also studied. The regions of the basins of attraction for the equilibrium points of the present dynamical model for some values of the mass parameters are illustrated.
DIFFERENT TYPES OF ATTRACTORS IN THE THREE BODY PROBLEM PERTURBED BY DISSIPATIVE TERMS
Authors: HADJIDEMETRIOU JOHN D. , VOYATZIS GEORGE
Published: July 2011

We study the evolution of a conservative dynamical system with three degrees of freedom, where small nonconservative terms are added. The conservative part is a Hamiltonian system, describing the motion of a planetary system consisting of a star, with a large mass, and of two planets, with small but not negligible masses, that interact gravitationally. This is a special case of the three body problem, which is nonintegrable. We show that the evolution of the system follows the topology of the conservative part. This topology is critically determined by the families of periodic orbits and their stability. The evolution of the complete system follows the families of the conservative part and is finally trapped in the resonant orbits of the Hamiltonian system, in different types of attractors: chaotic attractors, limit cycles or fixed points.
CHAINS OF ROTATIONAL TORI AND FILAMENTARY STRUCTURES CLOSE TO HIGH MULTIPLICITY PERIODIC ORBITS IN A 3D GALACTIC POTENTIAL
Authors: KATSANIKAS M. , PATSIS P. A. , PINOTSIS A. D.
Published: July 2011

This paper discusses phase space structures encountered in the neighborhood of periodic orbits with high order multiplicity in a 3D autonomous Hamiltonian system with a potential of galactic type. We consider 4D spaces of section and we use the method of color and rotation [Patsis & Zachilas, 1994] in order to visualize them. As examples, we use the case of two orbits, one 2-periodic and one 7-periodic. We investigate the structure of multiple tori around them in the 4D surface of section and in addition, we study the orbital behavior in the neighborhood of the corresponding simple unstable periodic orbits. By considering initially a few consequents in the neighborhood of the orbits in both cases we find a structure in the space of section, which is in direct correspondence with what is observed in a resonance zone of a 2D autonomous Hamiltonian system. However, in our 3D case we have instead of stability islands rotational tori, while the chaotic zone connecting the points of the unstable periodic orbit is replaced by filaments extending in 4D following a smooth color variation. For more intersections, the consequents of the orbit which started in the neighborhood of the unstable periodic orbit, diffuse in phase space and form a cloud that occupies a large volume surrounding the region containing the rotational tori. In this cloud the colors of the points are mixed. The same structures have been observed in the neighborhood of all m-periodic orbits we have examined in the system. This indicates a generic behavior.
ANTI-PHASE AND INVERSE π-LAG SYNCHRONIZATION IN COUPLED DUFFING-TYPE CIRCUITS
Authors: VOLOS CHRISTOS K. , KYPRIANIDIS IOANNIS M. , STOUBOULOS IOANNIS N.
Published: July 2011

The dynamic behavior of bidirectionally coupled Duffing-type circuits is numerically and experimentally investigated. Two related phenomena are explored such as anti-phase synchronization and inverse π-lag synchronization. Anti-phase synchronization is observed for the first time in coupled Duffing-type systems, while the inverse π-lag synchronization phenomenon in mutually coupled identical oscillators is a new type of synchronization. Inverse π-lag synchronization can be characterized by the vanishing of the sum of two relevant periodic signals. The first one is the signal of the first circuit x1and the second is the signal of the second circuit x2with a time lag τmin. This time lag is equal to T/2, where T is the period of x1and x2. The measurements and numerical computations suggest that these two synchronization phenomena are correlated with the symmetry under the transformation, x → -x, y → -y and t → t + T/2, which the Duffing equation exhibits.
NEW CONTACT-DEFINITION ALGORITHM USING INSCRIBED SPHERES FOR 3D DISCONTINUOUS DEFORMATION ANALYSIS
Authors: AHN TAE-YOUNG , SONG JAE-JOON
Published: July 2011

The speed and stability of three-dimensional (3D) discontinuous deformation analysis (DDA) are strongly dependent on the efficiency and correctness of contact detection and the definition algorithm, which affects the simultaneous equilibrium equations solved in every open–close iteration (OCI) retry. In particular, the definition of vertex-to-vertex contacts in a tangled zone may abruptly change the entrance planes, even in the case of very small displacement of the objects. This study proposes a new contact-definition algorithm using an inscribed sphere virtually installed in every contacting vertex. The suggested algorithm generates virtual entrance planes in the case of a vertex-to-vertex contact, and controls the accuracy of the contact definition process by adjusting the sphere size. Verification tests of the proposed algorithm indicate an increase in the efficiency and stability of 3D DDA.
QUALITY OF LIFE ASSESSMENTS AND SOCIAL SUSTAINABILITY: SKI TOURISM DEVELOPMENT IN INVERMERE, BRITISH COLUMBIA
Authors: ASPINALL ALISON , CUKIER JUDIE , DOBERSTEIN BRENT
Published: July 2011

The purpose of this study was to determine the feasibility of using quality of life assessments (QLA) to evaluate social sustainability and impacts of a hypothetical tourism development modelled after the currently-proposed Jumbo Glacier Resort. Results of this study indicated that there was a significant difference between the pre- and post-development scenarios on respondents' perceived quality of life: respondents perceived that their quality of life would be lower after the development of the resort. Also, respondents' general attitudes towards tourism development, and the specific Jumbo Glacier Resort project, had a statistically significant impact on their expected quality of life, and their interpretation of how tourism impacts their quality of life. The study suggests that quality of life assessment can make valuable contributions to the fields of social impact assessment and social sustainability analysis, and the results of such assessments can make valuable contributions to the fields of sustainable community development.
Application of acoustic fluid inclusion decrepitometry to gold exploration in Finland
Authors: Partamies Sami A. G. , Poutiainen Matti A. J.
Published: July 2011

Acoustic fluid inclusion decrepitometry was applied to five Archean and 14 Palaeoproterozoic gold deposits in order to evaluate the applicability of the method in gold (Au) exploration. The sample material consists mostly of Au–sulphide-bearing and barren quartz veins. The deposits are characterized by decrepigrams and fluid inclusion geochemistry. The decrepigrams exhibit different regional characteristics for the different domains but within these domains or single ore provinces they are usually very uniform and coherent.

The decrepigrams of mineralized and barren quartz veins show recognizable differences in their discrimination in areas where this can rarely be discerned by mere visual observation. Furthermore, the highest concentration of Au usually correlates with the peak frequency of gaseous (CO
2
and CH
4
) fluid inclusions which decrepitate at temperatures below 350°C, and with the highest amount of other fluid inclusion types (H
2
O–CO
2
±CH
4
and H
2
O), which decrepitate over a wide range at temperatures above 350°C. These results show that careful collection and assessment of decrepitation data may play a small but constructive role in Au exploration.
Biogeochemical prospecting for platinum group metals in eastern Siberia
Authors: Kovalevskii A. L.
Published: July 2011

Analysis of more than 25 000 plant samples, mostly rotted stumps and cones of Scots pine (
Pinus sylvestris
), has resulted in the discovery of several new types of platinum group metal (PGM) mineralization in weathered bedrock. Mineralization occurs in intrusions dominated by hybrid syenites of Palaeozoic age within the deeply faulted Gil’bera area of eastern Siberia. Plant ash contains up to 5000 ppb (ng g
−1
) Pt, in contrast to background levels of <1 ppb Pt. An initial survey revealed 12 biogeochemical anomalies, 1–10 m wide, with concentrations of 50–500 ppb Pt in plant ash. Subsequent trenching disclosed seven types of PGM mineralization: (1) stockworks up to several hundred metres in width; (2) smaller-scale PGM-rich zones (30–80 m wide) within these stockworks; (3) complex mineralized zones, 2–30 m wide, containing Au, Ag and from 2 to 6 of the PGM; (4) steeply-dipping zones, 0.2–3 m wide, within (3) above, containing only one PGM in one or two trees; (5) PGM in xenoliths of hydrothermally altered and skarnitized rocks; (6) zones of secondary alteration 1–5 m thick that blanket unweathered rock; and (7) lenses of secondary alteration. Of these seven categories of rocks hosting PGM, the most interesting occurrences fall within the weathered bedrock of group 6 from which PGM were mined
c.
100 years ago.
Leaching of loosely bound elements during wet grain size separation with sodium hexametaphosphate: implications for selective extraction analysis
Authors: Plouffe Alain , Hall Gwendy E. M. , Pelchat Pierre
Published: July 2011

Sodium hexametaphosphate, Na
6
(PO
3
)
6
, is often used as a dispersant in wet grain size separation procedures to obtain the clay-sized (<0.002 mm) fraction of till and soil samples. However, the complexing properties of this reagent can lead to a loss of elements through chemical leaching during the separation process. This work examines potential losses of Cr, Zn, Fe, Mn, Ni, Sb, and Hg from glacial sediment (till) to dispersant solution. Compared to dissolution by conventional aqua regia digestion, these losses are insignificant at <0.3%. However, if the elements in a loosely bound form are under study using selective or sequential leaches, then the losses can be viewed as substantial. Sodium hexametaphosphate solution, used as dispersant at a strength of 0.5%, was found to dissolve as much as 68% of the Hg in a bulk till sample (<4 mm) that would be brought into solution by a 1 M sodium acetate extractant at pH 5, designed to dissolve the adsorbed/exchangeable/carbonate phase of a geological sample. Up to 10% of the Hg and 7% of the Cr leached from the clay-sized fraction by 1 M NaOAc could have been lost to the Na
6
(PO
3
)
6
dispersant during the clay-sized separation. Consequently, the concentrations of labile or weakly bound forms of elements reported in a sequential extraction scheme could be reduced because of a loss to the Na
6
(PO
3
)
6
dispersant.
Primary alteration and geochemical dispersion haloes of Archaean orogenic gold deposits in the Yilgarn Craton: the pre-weathering scenario
Authors: Eilu P. , Groves D. I.
Published: July 2011

Widespread orogenic gold deposits are hosted by practically all rock types over the range of metamorphic grades in the Archaean Yilgarn Craton, Western Australia. They are normally located in second- or third-order structures, most commonly near crustal- to regional-scale deformation zones, in brittle, brittle–ductile and ductile deformational environments. Despite this extreme variability, the alteration and geochemical features of these deposits are strikingly consistent.

Each gold deposit is enveloped by an alteration-zoning sequence. In greenschist facies, the alteration zones are, from distal to proximal and according to the diagnostic minerals: calcite–chlorite, calcite–ankerite and sericite. In amphibolite facies, two zones are normally detected, a distal biotite and a proximal calc-silicate zone with no intermediate zone.

The ores are enriched in Ag, As, Au, Ba, CO
2
, K, Rb, S, Sb, Si, Te and W, and depleted in Na and Y relative to host-rocks. Base metals, Fe, Mg and Mn are rarely mobile in these settings. From the available, albeit limited, database there is little correlation between rock type or metamorphic grade and the elements enriched in the gold deposit. All enriched components may form primary dispersion haloes around the deposits. Parameters that most consistently define dispersion haloes for those deposits studied in the Yilgarn Craton are As, Au, Sb, Te, W, and the carbonation and sericitization indices. In nearly all cases, at least one of the parameters defines an anomaly significantly more extensive than that defined by Au alone. In some cases, Se or Y anomalies also extend beyond the Au anomaly. Importantly, there is also at least one pathfinder element whose primary dispersion extends beyond the alteration halo based on mineral assemblages, whereas the alteration–index anomalies normally do not extend beyond these limits. The primary geochemical dispersion halo may extend laterally for >200 m, and along strike for a few kilometres, from the gold orebody.

A single geochemical parameter rarely defines an extensive and consistent vector towards gold ore. However, useful directional information can be achieved when trends defined by several geochemical parameters are combined.
Evolution, classification and use of ferruginous regolith materials in gold exploration, Yilgarn Craton, Western Australia
Authors: Anand R. R.
Published: July 2011

Ferruginous regolith materials are abundant and widespread in the Yilgarn Craton of Western Australia and have been successfully used as sample media in Au exploration. However, their formation has been complex. They are developed in residual and transported materials of various ages. Four general types are recognized: ferruginous duricrust and gravel, ferruginous mottles, ferruginous saprolite and iron segregations. Ferruginous duricrusts include lateritic residuum and ferricrete. Lateritic residuum has evolved by partial collapse of mottled or ferruginous regolith, involving local vertical and lateral (generally 10–50 m) movements after chemical wasting. Ferricretes are ferruginized sediments. Some are detrital clasts cemented by Fe oxides and others are authigenic pisoliths and nodules in sandy or clayey sediments. Ferruginous mottles are formed by accumulation of hematite and goethite in saprolite, residual clays or sediments. Ferruginous saprolite is formed by the uniform ferruginization of saprolite. Iron segregations form by the replacement and/or modification of sulphide-rich lithologies or as exotic accumulation of Fe oxides along preferred pathways, such as fractures, faults and lithological contacts within saprolite.

Gold dispersion in the ferruginous zone of the profile is commonly considered to have a ‘mushroom’ shape formed by downward weathering, where the surficial Au halo is derived from the mineralization by a combination of chemical, residual and mechanical processes. In this study, appreciation of regolith–landform history provides an understanding of the nature of Au dispersion (or lack of it) in ferruginous materials. It has been possible to relate the mechanisms of dispersion of Au to the material being ferruginized, the environment of ferruginization and its position within a weathering profile. The distribution of Au at the micro-morphological scale provides evidence of a mobility related to the formation of particular facies of ferruginous duricrust. Accordingly, it is essential that careful attention is paid to characterization of potential ferruginous sample media and their location in the landscape in order to deduce their relationship to bedrock.
Exploration for gold using calcrete – lessons from the Yilgarn Craton, Western Australia
Authors: Lintern M. J.
Published: July 2011

This paper describes and reviews the use of calcrete (caliche) for Au exploration in the southern Yilgarn Craton of Western Australia. There are very strong correlations between Au and the alkaline earth metals, particularly in residual soils. However, where transported overburden exceeds about 10 m, the use of calcrete to indicate underlying Au mineralization is severely limited. Even where transported overburden is less than 10 m, other factors, such as thick clay, may restrict geochemical signals from reaching the calcrete. In some cases, gold in calcrete occurring over mineralization may have been sourced from upslope.

Several lessons are to be learnt from calcrete sampling in the Yilgarn WA. Some of the more important being:

Calcrete is an excellent sample medium for Au exploration because its physico-chemical properties appear to mimic those of the Au species found in soil, so that Au and Ca commonly accumulate in the same part of the soil profile.

Calcrete consists of a variety of materials and morphologies derived from the parent material on and within which it develops, although dominated by calcite and dolomite.

Gold found in calcrete may have been transported laterally up to several hundred metres – that is, its presence does not necessarily indicate Au mineralization directly below.

Regolith classification (including mapping and profiles) is essential to correctly interpret Au anomalies developed in calcrete.

If the thickness of transported overburden exceeds 10 m and/or if lacustrine sediments are present, experience to date suggests that calcrete will probably be ineffective as a sample medium.
Hydrogeochemistry in the Yilgarn Craton
Authors: Gray David J.
Published: July 2011

The hydrogeochemistry of the Yilgarn Craton and its margins has been extensively investigated, with particular emphasis on the chemistry of Au. Four groundwater regions have been delineated based on variations in salinity, acidity and oxidation potential: (1)
Northern
(N Yilgarn and margins) – Fresh and neutral, trending more saline in the valley axes; (2)
Central
– Neutral and brackish (commonly <1% TDS) to saline (about 3% TDS), trending to hypersaline (10–30% TDS) at the salt lakes, with common increases in salinity with depth; (3)
Kalgoorlie
– Commonly acid (pH 3–5), except where buffered by extremely alkaline materials (e.g. ultramafic rocks), and saline within the top part of the groundwater mass, trending more neutral (pH 5–7) and hypersaline at depth and within a few kilometres of salt lakes; and (4)
Eastern
(E Yilgarn and Officer Basin) – Saline to hypersaline, neutral to acid and reducing. Dissolved concentrations of many ions are low, due to the presence of lignites in the channel sediments.

These regional variations have major effects on the concentrations of many elements. Aluminium, Li, Y, REE and U are dominantly controlled by pH and thus have higher concentrations in acid groundwaters, such as those in the Kalgoorlie region. Dissolved concentrations of Mn, Co, Ni, Cu and Zn are less closely correlated with acidity, and show scope for lithological discrimination, but there is no apparent relationship with Au mineralization. Dissolved Cr shows an absolute correlation with ultramafic rocks, apparently irrespective of pH, possibly due to its presence as chromate (i.e. Cr
6+
as CrO
4
2−
). Concentrations of As, Sb Mo, W and Bi are low in acid groundwaters, but are higher above pH 6.5, particularly in the Central region. Therefore, acid groundwaters (particularly in the Kalgoorlie district) will be poor media for the use of these elements as exploration pathfinders. Molybdenum differs from the other elements in this group in having significant concentrations in acid groundwaters, although lower than in neutral and alkaline groundwaters.

Dissolved Au is commonly the best pathfinder for Au mineralization. It occurs dominantly as halides (chloride and/or iodide) and has enhanced concentrations (to >1 ppb) under the acid/saline/oxidizing conditions common in the Kalgoorlie region, whereas concentrations in the northern Yilgarn are two orders of magnitude less. This implies that supergene Au remobilization should be considerably less in the northern Yilgarn than in the Kalgoorlie region. Additionally, the threshold dissolved Au concentration as used for Au exploration differs significantly between regions.