bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Methicillin-Resistant
Staphylococcus aureus
Involvement in Disease Sites by Concomitant Nasal Sampling
Authors: Robicsek Ari , Suseno Mira , Beaumont Jennifer L. , Thomson Richard B. , Peterson Lance R.
Published: December 2007

Nasal colonization with methicillin-resistant
Staphylococcus aureus
(MRSA) is believed to precede disease. It is therefore reasonable to expect that testing for nasal MRSA colonization could provide guidance in the choice of empirical therapy for infections. We conducted a retrospective review of 5,779 nasal MRSA tests performed within a 24-h period before or after a clinical culture showed the growth of any organism. A positive nasal MRSA test strongly predicted MRSA involvement at a clinical site (relative risk, 12.9 times higher than in the remainder of the population; 95% confidence intervals [CI], 10.4, 16.1). Nasal MRSA colonization also strongly predicted antimicrobial resistance in other organisms. A negative nasal test was less useful; only 217 of 323 patients (67.2%; 95% CI, 61.8, 72.3) with clinical cultures involving MRSA had detectable, concomitant nasal MRSA colonization. Patients with clindamycin-susceptible MRSA infections were less likely (59%) to have nasal colonization than those with clindamycin-resistant MRSA infections (71%;
P
= 0.042). Patients nasally colonized with MRSA were substantially more likely to have antibiotic-resistant floras in clinical specimens, and this should be considered when initiating therapy. However, nearly a third of MRSA-infected patients were not nasally colonized, suggesting that nasal colonization need not precede disease and that a negative test for nasal colonization would not rule out MRSA disease in settings of moderate or high prevalence.
The Microbicide Tenofovir Does Not Inhibit Nucleic Acid Amplification Tests for Detection of
Chlamydia trachomatis
and
Neisseria gonorrhoeae
in Urine Samples
Authors: Wood Billie Jo , Rizzo-Price Patricia , Holden Jeff , Hardick Andrew , Quinn Thomas C. , Gaydos Charlotte A.
Published: December 2007

The potential inhibitory effects of tenofovir and a placebo were examined using the Becton Dickinson ProbeTec, Gen-Probe Aptima Combo 2, and Roche Amplicor tests to detect
Chlamydia trachomatis
and
Neisseria gonorrhoeae
. Concentrations of 5% to 0% of tenofovir and the placebo were added to dilutions of
C. trachomatis
and
N. gonorrhoeae
. No appreciable inhibition was observed.
Association of
Mycoplasma ovipneumoniae
Infection with Population-Limiting Respiratory Disease in Free-Ranging Rocky Mountain Bighorn Sheep (
Ovis canadensis canadensis
)
Authors: Besser Thomas E. , Cassirer E. Frances , Potter Kathleen A. , VanderSchalie John , Fischer Allison , Knowles Donald P. , Herndon David R. , Rurangirwa Fred R. , Weiser Glen C. , Srikumaran Subramaniam
Published: December 2007

Bronchopneumonia is a population-limiting disease in bighorn sheep in much of western North America. Previous investigators have isolated diverse bacteria from the lungs of affected sheep, but no single bacterial species is consistently present, even within single epizootics. We obtained high-quality diagnostic specimens from nine pneumonic bighorn sheep in three populations and analyzed the bacterial populations present in bronchoalveolar lavage specimens of seven by using a culture-independent method (16S rRNA gene amplification and clone library analyses).
Mycoplasma ovipneumoniae
was detected as a predominant member of the pneumonic lung flora in lambs with early lesions of bronchopneumonia. Specific PCR tests then revealed the consistent presence of
M. ovipneumoniae
in the lungs of pneumonic bighorn sheep in this study, and
M. ovipneumoniae
was isolated from lung specimens of five of the animals. Retrospective application of
M. ovipneumoniae
PCR to DNA extracted from archived formalin-fixed, paraffin-embedded lung tissues of historical adult bighorn sheep necropsy specimens supported the association of this agent with bronchopneumonia (16/34 pneumonic versus 0/17 nonpneumonic sheep were PCR positive [
P
< 0.001]). Similarly, a very strong association was observed between the presence of one or more
M. ovipneumoniae
antibody-positive animals and the occurrence of current or recent historical bronchopneumonia problems (seropositive animals detected in 9/9 versus 0/9 pneumonic and nonpneumonic populations, respectively [
P
< 0.001]).
M. ovipneumoniae
is strongly associated with bronchopneumonia in free-ranging bighorn sheep and is a candidate primary etiologic agent for this disease.
Equine Infectious Anemia Virus Entry Occurs through Clathrin-Mediated Endocytosis
Authors: Brindley Melinda A. , Maury Wendy
Published: December 2007

Entry of wild-type lentivirus equine infectious anemia virus (EIAV) into cells requires a low-pH step. This low-pH constraint implicates endocytosis in EIAV entry. To identify the endocytic pathway involved in EIAV entry, we examined the entry requirements for EIAV into two different cells: equine dermal (ED) cells and primary equine endothelial cells. We investigated the entry mechanism of several strains of EIAV and found that both macrophage-tropic and tissue culture-adapted strains utilize clathrin-coated pits for entry. In contrast, a superinfecting strain of EIAV, EIAV
vMA-1c
, utilizes two mechanisms of entry. In cells such as ED cells that EIAV
vMA-1c
is able to superinfect, viral entry is pH independent and appears to be mediated by plasma membrane fusion, whereas in cells where no detectable superinfection occurs, EIAV
vMA-1c
entry that is low-pH dependent occurs through clathrin-coated pits in a manner similar to wild-type virus. Regardless of the mechanism of entry being utilized, the internalization kinetics of EIAV is rapid with 50% of cell-associated virions internalizing within 60 to 90 min. Cathepsin inhibitors did not prevent EIAV entry, suggesting that the low-pH step required by wild-type EIAV is not required to activate cellular cathepsins.
Cooperative Effect of the Attenuation Determinants Derived from Poliovirus Sabin 1 Strain Is Essential for Attenuation of Enterovirus 71 in the NOD/SCID Mouse Infection Model
Authors: Arita Minetaro , Ami Yasushi , Wakita Takaji , Shimizu Hiroyuki
Published: December 2007

Enterovirus 71 (EV71) is a causative agent of hand, foot, and mouth disease and is also associated with serious neurological disorders. An attenuated EV71 strain [EV71(S1-3′)] has been established in the cynomolgus monkey infection model; this strain contains the attenuation determinants derived from the type 1 poliovirus vaccine strain, Sabin 1 [PV1(Sabin)], in the 5′ nontranslated region (NTR), 3D polymerase, and 3′ NTR. In this study, we analyzed the effect of the attenuation determinants of PV1(Sabin) on EV71 infection in a NOD/SCID mouse infection model. We isolated a mouse-adapted EV71 strain [EV71(NOD/SCID)] that causes paralysis of the hind limbs in 3- to 4-week-old NOD/SCID mice by adaptation of the virulent EV71(Nagoya) strain in the brains of NOD/SCID mice. A single mutation at nucleotide 2876 that caused an amino acid change in capsid protein VP1 (change of the glycine at position 145 to glutamic acid) was essential for the mouse-adapted phenotype in NOD/SCID mice. Next, we introduced attenuation determinants derived from PV1(Sabin) along with the mouse adaptation mutation into the EV71(Nagoya) genome. In 4-week-old mice, the determinants in the 3D polymerase and 3′ NTR, which are the major temperature-sensitive determinants, had a strong effect on attenuation. In contrast, the effect of individual determinants was weak in 3-week-old NOD/SCID mice, and all the determinants were required for substantial attenuation. These results suggest that a cooperative effect of the attenuation determinants of PV1(Sabin) is essential for attenuated neurovirulence of EV71.
Patterns of CD8+Immunodominance May Influence the Ability ofMamu-B*08-Positive Macaques To Naturally Control Simian Immunodeficiency Virus SIVmac239 Replication
Authors: Loffredo John T. , Bean Alex T. , Beal Dominic R. , León Enrique J. , May Gemma E. , Piaskowski Shari M. , Furlott Jessica R. , Reed Jason , Musani Solomon K. , Rakasz Eva G. , Friedrich Thomas C. , Wilson Nancy A. , Allison David B. , Watkins David I.
Published: December 2007

Certain major histocompatibility complex (MHC) class I alleles are strongly associated with control of human immunodeficiency virus and simian immunodeficiency virus (SIV). CD8+T cells specific for epitopes restricted by these molecules may be particularly effective. Understanding how CD8+T cells contribute to control of viral replication should yield important insights for vaccine design. We have recently identified an Indian rhesus macaque MHC class I allele,Mamu-B*08, associated with elite control and low plasma viremia after infection with the pathogenic isolate SIVmac239. Here, we infected fourMamu-B*08-positive macaques with SIVmac239 to investigate why some of these macaques control viral replication. Three of the four macaques controlled SIVmac239 replication with plasma virus concentrations below 20,000 viral RNA copies/ml at 20 weeks postinfection; two of four macaques were elite controllers (ECs). Interestingly, two of the four macaques preserved their CD4+memory T lymphocytes during peak viremia, and all four recovered their CD4+memory T lymphocytes in the chronic phase of infection. Mamu-B*08-restricted CD8+T-cell responses dominated the acute phase and accounted for 23.3% to 59.6% of the total SIV-specific immune responses. Additionally, the ECs mounted strong and broad CD8+T-cell responses against several epitopes in Vif and Nef. Mamu-B*08-specific CD8+T cells accounted for the majority of mutations in the virus at 18 weeks postinfection. Interestingly, patterns of viral variation in Nef differed between the ECs and the other two macaques. Natural containment of AIDS virus replication inMamu-B*08-positive macaques may, therefore, be related to a combination of immunodominance and viral escape from CD8+T-cell responses.
Activation of p90 Ribosomal S6 Kinase by ORF45 of Kaposi's Sarcoma-Associated Herpesvirus and Its Role in Viral Lytic Replication
Authors: Kuang Ersheng , Tang Qiyi , Maul Gerd G. , Zhu Fanxiu
Published: December 2007

The extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway is essential for infection by a variety of viruses. The p90 ribosomal S6 kinases (RSKs) are direct substrates of ERK and functional mediators of ERK MAPK signaling, but their roles in viral infection have never been examined. We demonstrate that ORF45 of Kaposi's sarcoma-associated herpesvirus (KSHV) interacts with RSK1 and RSK2 and strongly stimulates their kinase activities. The activation of RSK by ORF45 is correlated with ERK activation but does not require MEK. We further demonstrate that RSK1/RSK2 is activated during KSHV primary infection and reactivation from latency; a subset of RSK1/RSK2 is present in the viral replication compartment in the nucleus. Depletion of RSK1/RSK2 by small interfering RNA or the specific inhibitor BI-D1870 suppresses KSHV lytic gene expression and progeny virion production, suggesting an essential role of RSK1/RSK2 in KSHV lytic replication.
Lipid Intermediates in the Biosynthesis of Bacterial Peptidoglycan
Authors: van Heijenoort Jean
Published: December 2007

This review is an attempt to bring together and critically evaluate the now-abundant but dispersed data concerning the lipid intermediates of the biosynthesis of bacterial peptidoglycan. Lipid I, lipid II, and their modified forms play a key role not only as the specific link between the intracellular synthesis of the peptidoglycan monomer unit and the extracytoplasmic polymerization reactions but also in the attachment of proteins to the bacterial cell wall and in the mechanisms of action of antibiotics with which they form specific complexes. The survey deals first with their detection, purification, structure, and preparation by chemical and enzymatic methods. The recent important advances in the study of transferases MraY and MurG, responsible for the formation of lipids I and II, are reported. Various modifications undergone by lipids I and II are described, especially those occurring in gram-positive organisms. The following section concerns the cellular location of the lipid intermediates and the translocation of lipid II across the cytoplasmic membrane. The great efforts made since 2000 in the study of the glycosyltransferases catalyzing the glycan chain formation with lipid II or analogues are analyzed in detail. Finally, examples of antibiotics forming complexes with the lipid intermediates are presented.
VISCOELASTIC BEHAVIOR OF CONDUCTIVE POLYMER BASED ER DISPERSIONS UNDER SMALL DEFORMATIONS
Authors: KRZTOŃ-MAZIOPA ANNA , OSUCHOWSKI MARCIN , PŁOCHARSKI JANUSZ
Published: December 2007

ER fluids under shear are often approximated by the Bingham model with the electric field induced yield stress. This approach, however, neglects the properties of the solid phase created. The oscillation measurements taken under field below the yield point and leading to calculation of storage and loss moduli of the electrified solid do not allow for determination of the full stress–strain relationship of the solidified ER suspension. In order to overcome this problem and collect information about the mechanical properties of this solid a dedicated rheometer was constructed capable of measuring small strains under moderate stresses and under electric field. Full shapes of the stress–strain curves were recorded leading to determination of storage modulus, maximum deformation and yield point. Looking for relations between the viscoelastic behavior of ER suspensions and properties of their material components a series of fluids comprising silicone oil dispersions of conductive polymers (polyaniline, poly(p-phenylene), pyrolyzed polyacrylonitrile) and polymer electrolytes (polyacrylonitrile complexes with inorganic salts) was studied. It was found that the viscoelastic responses of ER fluids were affected by material characteristics of the dispersed phase.
EFFECTS OF BODY FORCES ON THE STRUCTURE AND RHEOLOGY OF ER AND MR FLUIDS
Authors: KLINGENBERG DANIEL J. , ULICNY JOHN C. , SMITH ANTHONY L.
Published: December 2007

We employ particle-level simulations to show that body forces, such as gravity or centrifugal forces, can significantly influence the structure and rheology of ER and MR suspensions even when the magnitude of the body force acting on a particle is small compared to the field-induced force. We also report an experimental investigation of the effects of body forces on the structure of ER suspensions. Experimental results agree qualitatively with predictions.
RHEOLOGICAL PROPERTIES OF NOVEL MAGNETORHEOLOGICAL FLUIDS
Authors: MANTRIPRAGADA S. , WANG X. , GORDANINEJAD F. , HU B. , FUCHS A.
Published: December 2007

The rheological properties of novel MR fluids are characterized using a parallel plate MR shear rheometer. In these MR fluids the surface of iron particles is coated with a polymer. The rheological properties are measured and compared at various magnetic field strengths, shear rates and strain amplitudes. It has been shown that these MR fluids exhibit stable and desirable rheological properties such as, low viscosity and high yield stress.
PHOSPHATE COATING ON THE SURFACE OF CARBONYL IRON POWDER AND ITS EFFECT IN MAGNETORHEOLOGICAL SUSPENSIONS
Authors: BOMBARD ANTONIO J. F. , KNOBEL MARCELO , ALCÂNTARA MARIA REGINA
Published: December 2007

Two types of carbonyl iron powders, (CIP's, BASF AG), the HS and HS-I (I = insulated, due a coating with phosphate), and two kinds of silica, one hydrophobic (Cab-O-Sil® TS610) and other hydrophilic (Cab-O-Sil® M5), were used to evaluate the influence of the surface treatment of the magnetic particle and the kind of fumed silica on the formulation of some magnetorheological suspensions (MRS). Oscillatory measurements at no field showed an evident difference between the silicas, but not a specific interaction with the phosphate coating on HSI. On the other hand, steady flow experiments also without magnetic field showed that the kind of silica and its specific interactions with the coating on iron powder drove the rheological behavior of the MRS on all region of the shear rate. Under magnetic field, the flow curves differences will be due to the iron particles and its magnetic properties, mainly on the region of higher shear rate.
MONITORING INTERPARTICLE DISTANCE IN MAGNETORHEOLOGICAL COMPOSITES
Authors: BOSSIS G. , COQUELLE E. , NOEL C. , GIULIERI F. , CHAZE A. M.
Published: December 2007

We describe two different systems, the first one based on a magnetorheological elastomer and the second one on magnetic particles inside a liquid crystal. In both system we manage to have chain structures with particles that are not in contact. The effect of the gap between particles on the viscoelastic properties are studied. We show in particular how in magnetorheological elastomers, the energy dissipation is closely related to the creation and the motion of cavities in the gap between the particles. In liquid crystal chaining of particles can occur without applying a magnetic field. This happens if the anchoring of liquid crystal on the surface of the particles is homeotropic. We demonstrate how the combination of elastic defects and of a magnetic field allow to obtain microscopic springs made of a pair of magnetic spheres.
FORMATION OF POLARIZED CONTACT LAYERS AND THE GIANT ELECTRORHEOLOGICAL EFFECT
Authors: HUANG XIANXIANG , WEN WEIJIA , YANG SHIHE , SHENG PING
Published: December 2007

The discovery of the giant electrorheological (GER) effect poses a challenge to the theorists for an explanation of its physical underpinnings. This is particularly the case as the GER effect breaks the yield stress upper bound predicted on the basis of induced polarization mechanism. The GER effect was observed in suspensions of coated nanoparticles, each consisting of a core particle of barium titanyl oxalate (20-50 nm), coated with a 5-7 nm layer of urea. The suspending oil is also very important, as the "wrong" oil can mean no electrorheological effect at all. Our prior work has shown the GER data, on the field dependence of yield stress, to be quantitatively accountable by the formation of aligned molecular dipolar layers in the region of particle-particle contact. Here we justify this picture through microscopic statistical mechanic considerations. We present a model of hydrogen bonding which can give rise to both electrowetting between the particles and the oil, as well as inducing the formation of aligned surface molecular dipolar layers. Monte Carlo simulation is used to account for both the entropy and energetic effects. It is shown that the formation of aligned surface dipolar layers can indeed be a robust phenomenon.
EXPERIMENTAL STUDIES ON MAGNETORHEOLOGICAL MODEL SUSPENSIONS
Authors: TRENDLER ALEXANDRA-MARIA , BÖSE HOLGER
Published: December 2007

Magnetorheological model suspensions with different contents of iron particles have been investigated. The results show an increase of the shear stress by increasing the magnetic field and the solid content, which was mathematically modelled. The influence of the solid content is approximately exponential without magnetic field and linear in strong magnetic fields. The effect of the temperature and of the base oil viscosity on the shear stress is negligible in the field but decisive without field. The sedimentation behavior also strongly depends on the iron particle content, where MR fluids with a higher concentration settle with a lower intensity due to the higher sediment height. The response time of the magnetorheological model suspensions could not be clearly determined, but it is less than 10 milliseconds.
PREPARATION AND MAGNETORHEOLOGICAL CHARACTERIZATION OF CI/PVB CORE/SHELL PARTICLE SUSPENDED MR FLUIDS
Authors: YOU J. L. , PARK B. J. , CHOI H. J. , CHOI S. B. , JHON M. S.
Published: December 2007

Hybrid magnetic particles of carbonyl iron ( CI ) /poly(vinyl butyral) ( PVB ) with core/shell microstructure ( CI - PVB ) were prepared in order to enhance the dispersion stability of the magnetorheological (MR) fluids. Since the composite particles of CI - PVB have a lower density than that of the pristine CI particles, they are regarded to improve the sedimentation problem of magnetic particles in the MR fluid when the particles are dispersed in a mineral oil and to make easy redispersion after caking. The PVB coating layers were found to play an important role in the steric repulsion between the relatively large CI particles. Morphology and composition of the CI - PVB particles were observed via SEM and TGA, respectively. Flow properties of both CI and CI - PVB based MR fluids were examined via a rotational rheometer in parallel plate geometry equipped with a magnetic field supplier.
CONCORDANCE OF BOUNDARY LINKS
Authors: LEVINE JEROME
Published: December 2007

We show that the twisted signature invariants of boundary link concordance derived from unitary representations of the free group are actually invariants of ordinary link concordance. We also show how the discontinuity locus of this signature function is determined by Seifert matrices of the link.
THE BIANCHI TYPE V MAGNETIZED STRING DUST COSMOLOGICAL MODEL IN GENERAL RELATIVITY
Authors: BALI RAJ , JAIN SHILPI
Published: December 2007

The Bianchi type V magnetized string dust cosmological model for perfect fluid distribution is investigated. We assume that the magnetic field is along the x direction, so F23 is the only nonvanishing component of Fij. We also find that F14 = 0 = F24 = F34 due to the assumption of infinite electrical conductivity. The behavior of the model in the presence and the absence of a magnetic field is also discussed.
CIRCULAR MOTION IN ACCELERATING BLACK HOLE SPACE–TIMES
Authors: BINI DONATO , CHERUBINI CHRISTIAN , GERALICO ANDREA , JANTZEN ROBERT T.
Published: December 2007

The motion of test particles along circular orbits in the vacuum C metric is studied in the Frenet–Serret formalism. Special orbits and corresponding intrinsically defined geometrically relevant properties are selectively studied.
SHORTCUTS IN PARTICLE PRODUCTION IN A TOROIDALLY COMPACTIFIED SPACE–TIME
Authors: HOFF DA SILVA J. M. , DA ROCHA R.
Published: December 2007

We investigate the particle production in a toroidally compactified space–time due to the expansion of a Friedmann cosmological model in ℝ3 × S1 outside a U(1) local cosmic string. The case of a Friedmann space–time is also investigated where torsion is incorporated in the connection. We present a generalization to toroidal compactification of p extra dimensions, where the topology is given by ℝ3 × Tp. Some implications are presented and discussed. Besides the dynamics of space–time, we investigate in detail the physical consequences of the topological transformations.
A SIMPLE ALGORITHM BASED ON FLUCTUATIONS TO PLAY THE MARKET
Authors: GIL L.
Published: December 2007

In Biology, all motor enzymes operate on the same principle: they trap favourable brownian fluctuations in order to generate directed forces and to move. Whether it is possible or not to copy one such strategy to play the market was the starting point of our investigations. We found the answer is yes! In this paper we describe one such strategy and appraise its performance with historical data from the European Monetary System (EMS), the US Dow Jones, the german Dax and the french Cac40.
Deformation bands in sandstone: a review
Authors: Fossen Haakon , Schultz Richard A. , Shipton Zoe K. , Mair Karen
Published: December 2007

Deformation bands are the most common strain localization feature found in deformed porous sandstones and sediments, including Quaternary deposits, soft gravity slides and tectonically affected sandstones in hydrocarbon reservoirs and aquifers. They occur as various types of tabular deformation zones where grain reorganization occurs by grain sliding, rotation and/or fracture during overall dilation, shearing, and/or compaction. Deformation bands with a component of shear are most common and typically accommodate shear offsets of millimetres to centimetres. They can occur as single structures or cluster zones, and are the main deformation element of fault damage zones in porous rocks. Factors such as porosity, mineralogy, grain size and shape, lithification, state of stress and burial depth control the type of deformation band formed. Of the different types, phyllosilicate bands and most notably cataclastic deformation bands show the largest reduction in permeability, and thus have the greatest potential to influence fluid flow. Disaggregation bands, where non-cataclastic, granular flow is the dominant mechanism, show little influence on fluid flow unless assisted by chemical compaction or cementation.
Rainfall-induced lahars in the Belham Valley, Montserrat, West Indies
Authors: Barclay Jenni , Alexander Jan , Sušnik Janez
Published: December 2007

Rain falling on loose volcanic debris over the Soufrière Hills Volcano, Montserrat generates hazardous floods in the Belham Valley. These rainfall-induced lahars vary greatly in discharge and sediment concentration in space and time. They differ from examples documented on other volcanoes in that: (1) the eruption has been continuing since July 1995, generating repeated pulses of excess sediment; (2) rainfall is the only significant trigger; (3) the system is small, with short distance to the sea and relatively low altitude at the catchment top. Repeat mapping and comparison with pre-eruption data demonstrate significant geomorphological change, with
c
. 120 m shoreline progradation and
c
. 0.4 m a
−1
mean aggradation rate in the middle to lower valley. The nature of the hazard and area of risk have changed as the valley has aggraded, the channel widened and the runoff efficiency increased (as a result of rilling and vegetation removal). Lahars in the Belham Valley correlate with days when >10 mm rain fell in 24 h, with more events triggered in the late rainy season. The flows are mainly Newtonian but one non-Newtonian flow event has been demonstrated and is described in detail (20 March 2000). This flow is explained by direct volcanic ash input to the runoff.
Elastic dislocation modelling for prediction of small-scale fault and fracture network characteristics
Authors: Dee S. J. , Yielding G. , Freeman B. , Healy D. , Kusznir N. J. , Grant N. , Ellis P.
Published: December 2007

Predicting the effects of small-scale faults and fractures on reservoir behaviour requires a definition of their spatial distribution, orientation and mode. Elastic dislocation (ED) theory can predict the distribution of displacement, strain and stress in the rock volume surrounding major faults, from mapping of fault geometry and slip distribution in 3D seismic-reflection datasets. The intensity of small-scale faulting can be related to the predicted local strain, or the degree to which the shear stresses exceeded the rock failure envelope. We illustrate the methodology with three case studies: (i) a relatively-simple thrust anticline from Venezuela, where hydrocarbons are trapped in Pliocene sandstones within the faulted hanging wall anticline; (ii) the Gull-faks Field and of the North Sea; and (iii) the Miskar Field, offshore Tunisia, where large seismically mapped normal faults are forward-modelled to predict small-scale fault characteristics for comparison with detailed interpretation and seismic attribute analysis. Key requirements for the development of a robust predictive model of the small-scale fault and fracture network are a geometrically consistent framework model, judicious choice of mechanical properties, and a reasonable estimate of regional background strain.
Fold amplification and style transition involving fractured dip-domain boundaries: buckling experiments in brittle paraffin wax multilayers and comparison with natural examples
Authors: Bazalgette L. , Petit J.-P.
Published: December 2007

Experiments aiming to study the conditions of fracture localization during buckle folding in brittle sedimentary layers of the upper crust were conducted using brittle paraffin wax multilayers submitted to axial and vertical load. The particular aim was to understand the mechanisms of development of subtle features often observed in apparently rounded natural folds. These consist of scarcely visible discontinuous fractured zones, more or less parallel to the fold axis, that separate domains of constant dip. These zones are of great interest for fluid dynamics in folded fractured reservoirs. It is shown that such axial kink boundaries referred to as dip-domain boundaries (DDBs) play a major role in the development of curvature in fractured buckle folds. DDBs observed in experiments consist of the localization and coalescence of tensile fractures along axial planes after the elastic instability stage. The tested physical parameters were (1) the intensity of the vertical load, (2) the bed thickness within a mechanical unit of constant thickness, (3) the stiff (multilayer)-soft (embedding material) thickness ratio and (4) the interlayer friction. In low interlayer friction conditions DDBs remain relatively localized during shortening, leading to chevron-style folds. With high interlayer friction conditions, DDBs tend to multiply laterally from an initial chevron fold. The latter phenomenon leads towards a more rounded fold, but one that still shows discontinuous curvature comparable to that observed in natural conditions. Fold models of flexural slip and tangential longitudinal strain (orthogonal flexure) are discussed under the influence of tensile failure in multilayer materials.
Flow potential of fracture corridors and large conductive fractures in a clastic reservoir, Oman
Authors: Ozkaya S. I. , Minton K. R.
Published: December 2007

Borehole image logs, without accompanying flowmeter logs, are found to be of little use in identifying fluid conductive faults and fractures in a clastic reservoir in Oman. Both high permeability opening mode fluid conductive fractures and low-permeability deformation bands filled with sand and clay gouge appear conductive on image logs. Regional tectonic evolution and the nature of structural elements do not provide sufficient information to differentiate fluid conductive seismic faults or fault segments. Rapid water breakthrough may be indicative of fluid conductive faults and large fractures, but water cut rise is complex. The effect of faults and fractures may be masked by spud date, and water fingering through highly permeable layers, especially when the percentage of fluid conductive fault segments and fractures is low. Faults, deformation bands and large conductive fractures are found to cause openhole log spikes in this field. Since openhole logs are available from a large number of horizontal wells, it becomes feasible to prepare risk maps from map distribution of openhole log spikes even though it is not possible to pinpoint the exact location of fluid conductive faults and large fractures.
Stone decay induced by fire on historic buildings: the case of the cloister of Lisbon Cathedral (Portugal)
Authors: Dionísio A.
Published: December 2007

Lisbon Cathedral, built in Late Romanesque style, is one of the most ancient Portuguese monuments. Its cloister was severely damaged by a fire that occurred in 1755 right after an earthquake. The aim of this investigation is to study stone thermal damage through the application of
in situ
and laboratory techniques. With this study it is possible to identify and characterize (chemically and mineralogically) the main thermal decay forms. Special attention is given to colour modification and granular disintegration. Through the application of an indirect ultrasound method it is verified that only a small number of stone blocks are relatively sound (11%). In terms of chromatic alteration, two factors are considered to explain heat-induced colour modification: the transformation of goethite into hematite and an increase in hematite single crystalline domains. It is also established that the most probable high-temperature range to which the cloister stones were subjected during the fire was 300–350 °C.
Effect of long-term changes in air pollution and climate on the decay and blackening of European stone buildings
Authors: Grossi C. M. , Brimblecombe P.
Published: December 2007

This paper reviews the long-term effects of past, present and future air pollution and climate on the decay of stones from historic buildings. It summarizes the historical effects as well as causes and consequences of damage. The most significant change in terms of pollution has been a shift from high levels of sulphate deposition from coal burning to a blackening process dominated by diesel soot and nitrogen deposition from vehicular sources in cities. Blackening of light-coloured fabric eventually reaches a point where it becomes publicly unacceptable. Public opinion can assist the development of aesthetic thresholds and derive limit values for elemental carbon in urban air. Public perception is also affected by the pattern of blackening. This century new climate regimes will cause dramatic changes in blackening patterns by wind-driven rain. Climate changes, most particularly changes in temperature, humidity stress and time of wetness, can also affect the weathering of stone in terms of responses to frost and soluble salts. Future pollution and climate are relevant considerations in the management of historic buildings.
Dilation of building materials submitted to frost action
Authors: Thomachot C. , Matsuoka N.
Published: December 2007

This paper presents the results of laboratory frost weathering of five geomaterials used in stone monuments showing more or less frost damage: two sandstones (France), molasses (Switzerland), and a volcanic tuff and brick (Japan). Samples were submitted to unidirectional freezing simulations during which temperature and dilation were measured. The aim of these experiments was to understand which internal or external factors prevailing on dilation would lead to cracking. Results showed that water supply and repetition of freeze-thaw cycles were most important in the dilation of the materials. They also showed that the materials with the weakest transfer properties by capillary absorption were the most sensitive to frost action.
Green walls?: integrated laboratory and field testing of the effectiveness of soft wall capping in conserving ruins
Authors: Viles H. A. , Wood C.
Published: December 2007

Soft wall capping, which involves placing a cap of soil and turf (or other vegetation) on the top of ruined walls, is a potentially low cost, easy to maintain, ecologically sensitive and effective method of conserving ruined monuments. An integrated programme of laboratory and field testing has been designed to test the performance of soft capping in comparison with hard capping at a range of sites in England. A sample of ruined walls has been soft capped and monitored using repeat photography, with more detailed wooden dowel monitoring of wall moisture and electronic monitoring of temperatures and moisture levels at the base of soft caps at some sites. Experiments designed to test the thermal blanketing capability of the soft caps have been run in an environmental cabinet on scaled-down versions of soft and hard caps, and similar set-ups have also been monitored outdoors in Oxford. Short-term data from both field trials and laboratory tests illustrate the success of soft wall capping under a wide range of environmental conditions, but longer-term monitoring is needed to evaluate more fully the conservation benefits of soft capping.
The
ad
60 Denizli Basin earthquake and the apparition of Archangel Michael at Colossae (Aegean Turkey)
Authors: Piccardi Luigi
Published: December 2007

This paper illustrates the results of a multidisciplinary study on the active tectonics of Hierapolis and Colossae in Aegean Turkey. Tectonic analysis is combined with a study of historical seismicity, highlighting the use of historical sources from oral tradition (legends and myths) to derive important geological information for which the legendary account is the only witness. Strong correlation between tectonic and historical/mythological data suggests that the legendary narration is based on real geological events. This allows a better understanding of the local active tectonics and seismic history. At Hierapolis, it is possible to recognize evidence of surface faulting from the
ad
60 earthquake. At Colossae, we can reconstruct the local geomorphic evolution, and show its relationship to the
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60 earthquake.
Sorption of lanthanum onto clay minerals: a potential tracer for fine sediment transport in the coastal marine environment?
Authors: Spencer K. L. , James S. L. , Taylor J. A. , Kearton-Gee T.
Published: December 2007

In order to improve predictions of coastal morphological response to sea-level rise and sustainably manage dredged sediment there is an urgent need to develop a field methodology that can measure accurately transport pathways of the <63 µm sediment fraction in coastal and estuarine environments. Techniques such as sediment trend analysis and sediment tracing using fluorescent sands are well established for the silt and sand fraction but are unsuitable for clay sediments due to their cohesive nature. Geochemically labelled clays have been used as fine sediment tracers in freshwater environments with some success, although little is known about their chemical or physical behaviour once released in saline environments.

A number of pure clays and natural estuarine sediments were labelled with La following agitation in a 0.01 M solution of La Cl
3
. In order to examine the retention of La on the clay mineral surface the labelled sediment was washed sequentially four times using both de-ionised water and artificial seawater. A labelled bentonite retained 43000 µg g
-1
La and this was only reduced to 36000 µg g
-1
La after washing in seawater. This suggests that retention of La is good even in saline conditions and concentrations of La are high enough to enable detection after considerable signal dilution. Sorption of La is dependent predominantly upon the cation exchange capacity of the sediment.
Use of swath bathymetry in the investigation of sand dune geometry and migration around a near shore ‘banner’ tidal sandbank
Authors: Schmitt Thierry , Mitchell Neil C. , Ramsay Tony S.
Published: December 2007

Banner tidal sandbanks in the Bristol Channel have been repeatedly surveyed with a multibeam sonar to study the geometry and migration patterns of superimposed dunes. The data presented in this paper constitute one of the first studies concerned with sediment transport around a banner sandbank (Helwick Sands in the Bristol Channel) using repeated swath- bathymetry. The data reveal that the dunes maintain their shapes over a period of 11 months, and that they migrate in opposite directions on the alternate sides of the bank. Curiously, dunes connect over the crest of the bank despite opposing sediment transport directions on the flanks. Dune height increases with water depth as found in similar environments. We suggest how the morphology of the dunes results from the complex interaction between surface waves and tidal currents that occurs within the proximity of the headland.
Micritic fabrics define sharp margins of Wenlock patch reefs (middle Silurian) in Gotland and England
Authors: Kershaw Steve , Li Yue , Guo Li
Published: December 2007

Silurian reefs are well known to comprise frame-building corals, stromatoporoids and algae, but also a range of calcimicrobial components and micritic sediments of possible microbial origin. The margins of Wenlock patch reefs tend to have diffuse edges that grade into the surrounding bedded facies because of talus shed from the reefs. However, portions of patch reefs show sharp-bounded reef margins, with bedded limestones terminating abruptly against the reef edge. Examples of sharp boundaries where the reef comprises only carbonate mudstone-wackestone with poorly-defined gross fabric, and containing no metazoan framework, have been found in Wenlock patch reefs the UK and Gotland. Although in some cases the micrite may demonstrate a peloidal structure, in others there is no clear structure, broadly fitting the aphanitic (structureless) type of fabric found in leiolites (suspected microbial facies that show no structure). The fabrics are interpreted to have been formed by microbial mediation of micrite precipitation as part of reef construction, and are therefore automicrites. In all cases the sharp reef edges indicate coherence of the micritic fabric, interpreted as a lithified wall against which bedded limestones were deposited. This arrangement supports published interpretations of pronounced topography of Wenlock patch reefs, and shows the presence of steep, vertical and, possibly, overhanging reef margins, formed prior to bedded sediment accumulation. Thus, there is likely to have been a time interval between reef formation and deposition of bedded sediments, possibly caused by reef upward growth in transgressive settings, followed by catch-up of bedded limestone deposition.
Glacial contourites on the Antarctic Peninsula margin: insight for palaeoenvironmental and palaeoclimatic conditions
Authors: Lucchi Renata G. , Rebesco Michele
Published: December 2007

Deep-sea finely laminated and barren glacial sediments occur in the sediment drift field offshore the Pacific margin of the Antarctic Peninsula where a weak contour current flows at present to the SW. Atypical sedimentary facies were related to the coexistence and interaction of different sedimentary processes. Three ‘end-members’ of radiograph facies were defined to represent the sedimentary sequences controlled by a dominant process, as follows. (1) Direct influence of turbidity currents on sedimentation is observed in the area surrounding the Alexander Channel system with silty layers interbedded with laminated mud free of ice-rafted debris (IRD). (2) Distal meltwater turbid flows dominate the more proximal area of the top plateau with structureless and coarser-grained sediments containing IRD. (3) Along the crest of the drift, persistent weak bottom currents control the deposition of fine-grained sediments conveyed into the system through other processes. These laminated sediments contain IRD and are, atypically, not bioturbated, because of unusual, climatically related, environmental conditions of suppressed primary productivity and oxygen-reduced deep waters. These glacial contourites were observed on most of the Antarctic margin with the exception of the areas in which polynyas were maintained during the glacial stages. Glacial contourites can be used as a proxy to define temporal and spatial extension of the Antarctic sea-ice.
The Eirik Drift: a long-term barometer of North Atlantic deepwater flux south of Cape Farewell, Greenland
Authors: Hunter S. E. , Wilkinson D. , Stanford J. , Stow D. A. V. , Bacon S. , Akhmetzhanov A. M. , Kenyon N. H.
Published: December 2007

The Eirik Drift lies on the slope and rise off the southern tip of the Greenland margin where it formed under the influence of the North Atlantic deep western boundary current. The drift contains a semi-continuous and often expanded sedimentary record ranging from Early Eocene to Holocene and so contains a record of bottom current strengths over decadal to millennial time scales. These variations in current strength can be related to changes in thermohaline circulation and climate. The drift body is composed of four seismic sequences, with a number of internal discontinuities, reflecting a variety of palaeoceanographic events. Three secondary ridges are observed trending to the NW from the main ridge crest. The presence of these ridges, which have been active since the Early Pliocene, suggests that the deep current separates into three strands as it crosses the Eirik Drift, with each strand depositing a separate ridge. Variation in the degree of lateral migration within the Early to Late Pliocene sequence between ridges reflects local variation in the angle of slope on which the ridges formed. Cyclicity of reflector amplitude within the Late Pliocene to Pleistocene sequence could reflect changes in carbonate accumulation and deep current strength linked to glacial-interglacial variations.
Influence of caffeine ingestion on perceived mood states, concentration, and arousal levels during a 75-min university lecture
Authors: Peeling Peter , Dawson Brian
Published: December 2007

This investigation aimed to assess the effect of a caffeine supplement on perceived mood state, concentration, and arousal during a 75-min university lecture. Methods. This randomized, blind, cross-over design investigation ran over a course of 2 consecutive weeks. During week 1, 10 third-year Human Movement and Exercise Science students were assigned to either a caffeine- or placebo-supplemented group and were subsequently required to attend a 75-min exercise rehabilitation lecture. Seven days later, students were assigned to the opposite supplementation group before attending a second follow-on lecture, equal in duration to that of week 1. At the conclusion of each lecture, students were required to complete a mood perception questionnaire to assess the perceived level of mood state, concentration, and arousal during the lecture. The results showed that after caffeine consumption, students perceived themselves to be significantly more awake, clear minded, energetic, alert, and anxious ( P < 0.05). Additionally, students also felt they were better able to concentrate and had a greater level of arousal than when the placebo was consumed ( P < 0.05). In conclusion, the results of this investigation show that university students report enhanced perceptual feelings of behavior and mood state when a low dose of caffeine is consumed 60 min prior to a 75-min academic lecture.
Edemagenic gain and interstitial fluid volume regulation
Authors: Dongaonkar R. M. , Quick C. M. , Stewart R. H. , Drake R. E. , Cox C. S. , Laine G. A.
Published: December 2007

Under physiological conditions, interstitial fluid volume is tightly regulated by balancing microvascular filtration and lymphatic return to the central venous circulation. Even though microvascular filtration and lymphatic return are governed by conservation of mass, their interaction can result in exceedingly complex behavior. Without making simplifying assumptions, investigators must solve the fluid balance equations numerically, which limits the generality of the results. We thus made critical simplifying assumptions to develop a simple solution to the standard fluid balance equations that is expressed as an algebraic formula. Using a classical approach to describe systems with negative feedback, we formulated our solution as a “gain” relating the change in interstitial fluid volume to a change in effective microvascular driving pressure. The resulting “edemagenic gain” is a function of microvascular filtration coefficient ( K f), effective lymphatic resistance ( R L), and interstitial compliance ( C). This formulation suggests two types of gain: “multivariate” dependent on C, R L, and K f, and “compliance-dominated” approximately equal to C. The latter forms a basis of a novel method to estimate C without measuring interstitial fluid pressure. Data from ovine experiments illustrate how edemagenic gain is altered with pulmonary edema induced by venous hypertension, histamine, and endotoxin. Reformulation of the classical equations governing fluid balance in terms of edemagenic gain thus yields new insight into the factors affecting an organ's susceptibility to edema.