bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Order Model Dynamics of the Forced Cylinder Wake
Authors: Mureithi N. W. , Huynh K. , Pham A.
Published: July 2010

The periodically forced cylinder wake exhibits complex but highly symmetrical patterns. In recent work, the authors have exploited symmetry-group equivariant bifurcation theory to derive low order equations describing, approximately, the dominant nonlinear dynamics of wake mode interactions. The models have been shown to qualitatively predict the observed bifurcations suggesting that the Karman wake remains, dynamically, a fairly simple system at least when viewed in 2D. Preliminary experimental data are presented supporting the feasibility of using 2D simulation results for the derivation of the low order model parameters. A POD analysis of the wake PIV velocity field yields flow modes closely similarly to those obtained via 2D CFD computations for Re in the 1000 range. The paper presents new results of simulations for Re = 200. For this low Reynolds number, the forced Karman wake exhibits rich dynamics dominated by quasi-periodicity, mode locking, torus doubling and chaos. The low Re torus breakdown may be explained by the Afraimovich-Shilnikov theorem. Interestingly, in a previous analysis for the higher Re number, Re = 1000, transition to a period-doubled flow state was found to occur via a route akin to the Takens-Bogdanov bifurcation scenario.
The Effect of Post-Irradiation Annealing on VVER-440 RPV Materials Mechanolocal Properties and Nano-Structure Under Re-Irradiation
Authors: Rogozkin S. , Chernobaeva A. , Aleev A. , Nikitin A. , Zaluzhnyi A. , Erak D. , Shtrombakh Ya. , Zabusov O. , Debarberis L. , Zeman A.
Published: July 2010

The present work provides the analyses of embrittlement behavior and atom probe tomography study of nano-structure evolution of VVER-440 RPV materials under irradiation and re-irradiation. Specimens from VVER-440 weld with high level of cupper (0.16 wt.%) and phosphorus (0.027–0.038 wt.%) were irradiated in surveillance channels of Rovno Nuclear Power plant unit 1 (Ro-1). The embrittlement behavior has been assessed by transition temperature shift.
Recent Developments in High Temperature Codes
Authors: Dogan Bilal , Ainsworth R. A.
Published: July 2010

The codes and standards specify design rules and methods for assessing defects in structures in service. Recent international effort on design and assessment of components subjected to quasi-static and cyclic loading at high temperatures has focused on the issue of Creep-Fatigue damage and condition assessment, which to date have not been comprehensively addressed in codes. The work has concentrated on basic understanding of material behavior and methods for analyzing laboratory data in order to address the need for service life assessment of components in ageing plants. This recognizes that power plants, on average 35 years in service, are facing increased operational demands imposed in order to respond to the increasing electricity demand. This paper gives an overview of the subject procedures and recent developments in codes and standards. Novel features of the procedure developments relative to the existing high temperature assessment procedures are highlighted.
Effect of Load Eccentricity on the Behavior of a Bolted Joint With a Yielded Fastener
Authors: Nassar Sayed A. , Ganganala Mohan
Published: July 2010

A nonlinear model is proposed for studying the effect of the eccentricity of applied tensile forces on the clamp load loss in bolted joints that were initially tightened beyond the bolt elastic limit. The joint may not have been yielded at initial assembly, however. A closed form solution is obtained for the amount of clamp load loss due to a cyclic separating force. The proposed model takes into account two sources of nonlinearity; namely, the strain hardening behavior of the yielded bolt material as well as the nonlinear deformation behavior of the clamped plates under an external separating load. After the initial tightening of the fastener past its elastic limit, the subsequent application of a tensile separating force on the joint tends to increase the fastener tension in a nonlinear fashion, and simultaneously reduce the clamping force in the bolted joint from its initial value. Upon the removal of the cyclic tensile load, the bolted joint system reaches a new equilibrium point between the residual fastener tension, and the joint clamping force. At the new equilibrium point, the fastener tension is reduced from its preload due to its plastic elongation; simultaneously, a partial-yet permanent-loss in the clamp load level takes place. Excessive clamp load loss may lead to joint leakage, fastener loosening, or fatigue failure. For a known amplitude of the external cyclic tensile load, the increase in bolt tension and corresponding reduction in the joint clamp load are highly sensitive to the eccentricity of the tensile load (from the bolt center). Variables studied include the eccentricity value of the separating load, the rate of strain hardening of the bolt material, compressive and tensile stiffnesses of the clamped plates, bolt stiffness, bolt preload, and the magnitude of the separating tensile load.
Cyclic Behavior and Fatigue of Stainless Surge Line Material
Authors: Solin Jussi , Nagel Gerhard , Mayinger Wolfgang
Published: July 2010

Fatigue of Niobium stabilized austenitic stainless steel (X6CrNiNb1810mod) was studied using specimens extracted from a solution annealed and quenched φ360×32 mm pipe, which fulfils all the German KTA material requirements for primary components in BWR and PWR. An experimental strain life fatigue curve was determined as a base line for component specific evaluations and for comparison with the Langer and Chopra curves, which are the basis of the ASME III and NRC RG 1.207 design criteria. Stress strain responses in strain controlled tests were carefully measured to clarify the fatigue mechanisms. In the LCF regime our data lie within a common scatter band between the Langer and Chopra curves. When approaching HCF regime (> 100 000 cycles), the curves deviate and Chopra curve becomes highly conservative for this material. Strain controlled fatigue tests ranging to 10 million cycles in RT air indicated an endurance limit behavior for this alloy.
Polar catastrophe and the spin-polarized electron gas at the LaMnO3/SrMnO3 interface
Authors: Nanda B. R. K. , Satpathy S.
Published: July 2010

From calculations using ab initio density-functional methods, the authors show that analogous to the much-studied polar LaAlO3/SrTiO3 interface, there also forms a two-dimensional electron gas at the LaMnO3/SrMnO3 (100) interface due to the polar catastrophe. The electron gas originates from the accumulation of half an electron per cell to quench the polar catastrophe and from the leakage of Mn(eg) electrons from the LaMnO3 side to the SrMnO3 side. These electrons mediate a ferromagnetic double-exchange interaction between the Mn moments at the interface, causing the interface region to be ferromagnetic and in turn the electrons becoming spin-polarized owing to the Zeeman field of the Mn moments.
Nanoscale electrical characterization of arrowhead defects in GaInP thin films grown on Ge
Authors: Beinik I. , Galiana B. , Kratzer M. , Teichert C. , Rey-Stolle I. , Algora C. , Tejedor P.
Published: July 2010

In this work the authors present an electrical characterization of the so called arrowhead defects (ADs) in GaInP thin films grown on Ge(100) substrates misoriented by 6° toward (111). The samples have been evaluated by means of conductive atomic force microscopy (C-AFM) and Kelvin probe force microscopy (KPFM). It is shown that the ADs have terminating planes which are composed from two alternating subplanes inclined 12° (close to {105} plane) and 6° (close to {109}) with respect to the (100) plane. The terminating planes of the arrowhead defects possess higher conductivity compared to their surrounding. The terminating planes differ also in their electrical behavior from each other, demonstrating different values of conductivity (C-AFM) and bucking voltages (KPFM). The difference in current densities between two terminating planes was found to be ∼170±35 μA/m2 at −3 V, and the difference in the bucking voltages was ∼70 mV at 5 V of the electrical excitation signal in the lift mode. It is suggested that the distinctive electrical behavior of the ADs is caused by an ordering effect which leads in this case to the degraded electrical properties of the ADs.
Novel technique for formation of metal lines by functional liquid containing metal nanoparticles and reduction of their resistivity by hydrogen treatment
Authors: Kieu Nguyen Thi Thanh , Ohdaira Keisuke , Shimoda Tatsuya , Matsumura Hideki
Published: July 2010

A novel technique for formation of metal lines for electronic devices, and for reduction of resistivity in such metal lines, is proposed. In the technique, the metal lines are formed in trenches by using functional liquids containing metal nanoparticles. The trenches are constructed on a plastic substrate by imprint of a patterned mold. When the whole surface of the plastic substrate is covered with a hydrophobic film, the hydrophobic property disappears only in the trenches due to the pressing process of the imprint, and thus the functional liquid automatically accumulates into the trenches. When the metallic functional liquid is modified with tween-20 (polyoxyethylene-20), metal lines with a width of 10 μm are formed by capillary effect. The resistivity of such metal lines can be lowered to the order of 10−6 Ω cm by exposing them to hydrogen atoms generated in vacuum by catalytic cracking of hydrogen molecules with heated tungsten wires.
Twenty-Five Years of Translational Medicine in Antiretroviral Therapy: Promises to Keep
Authors: Broder Samuel
Published: July 2010

Early translational research on dideoxynucleoside drugs set HIV-1/AIDS on a path from a belief in the futility of antiretroviral therapy to the current array of therapeutic options.
Recombinant Innovation and Translational Science Trainees
Authors: Meyers Frederick J.
Published: July 2010

Diversely trained young scholars form the center of an innovation network in translational medicine.
New Antiseptic Peptides To Protect against Endotoxin-Mediated Shock
Authors: Gutsmann Thomas , Razquin-Olazarán Iosu , Kowalski Ina , Kaconis Yani , Howe Jörg , Bartels Rainer , Hornef Mathias , Schürholz Tobias , Rössle Manfred , Sanchez-Gómez Susana , Moriyon Ignacio , Martinez de Tejada Guillermo , Brandenburg Klaus
Published: July 2010

Systemic bacterial infections are associated with high mortality. The access of bacteria or constituents thereof to systemic circulation induces the massive release of immunomodulatory mediators, ultimately causing tissue hypoperfusion and multiple-organ failure despite adequate antibiotic treatment. Lipid A, the “endotoxic principle” of bacterial lipopolysaccharide (LPS), is one of the major bacterial immunostimuli. Here we demonstrate the biological efficacy of rationally designed new synthetic antilipopolysaccharide peptides (SALPs) based on the
Limulus
anti-LPS factor for systemic application. We show efficient inhibition of LPS-induced cytokine release and protection from lethal septic shock
in vivo
, whereas cytotoxicity was not observed under physiologically relevant conditions and concentrations. The molecular mechanism of LPS neutralization was elucidated by biophysical techniques. The lipid A part of LPS is converted from its “endotoxic conformation,” the cubic aggregate structure, into an inactive multilamellar structure, and the binding affinity of the peptide to LPS exceeds those of known LPS-binding proteins, such as LPS-binding protein (LBP). Our results thus delineate a novel therapeutic strategy for the clinical management of patients with septic shock.
Optimized Nile Red Efflux Assay of AcrAB-TolC Multidrug Efflux System Shows Competition between Substrates
Authors: Bohnert Jürgen A. , Karamian Brian , Nikaido Hiroshi
Published: July 2010

AcrAB-TolC is the major constitutively expressed efflux pump system that provides resistance to a variety of antimicrobial agents and dyes in
Escherichia coli
. However, no systematically optimized real-time dye efflux assay has been published for the measurement of its activity and for detection of possible competition between substrates. Here, we report on the development of such an assay using a lipophilic dye, Nile Red. Energy-depleted cells were loaded with the dye in the presence of low (10 μM or less) concentrations of the proton conductor carbonyl cyanide
m
-chlorophenylhydrazone (CCCP). The CCCP was then removed, and efflux was triggered by energization with glucose. Various known efflux pump inhibitors and antimicrobials were checked for the ability to slow down Nile Red efflux, presumably through competition. Besides the known inhibitors Phe-Arg-β-naphthylamide and 1-naphthyl-methylpiperazine, several tetracyclic compounds (doxorubicin, minocycline, chlortetracycline, doxycycline, and tetracycline) and tetraphenylphosphonium chloride were found to interfere with dye efflux. This inhibition could not be explained by the depletion of proton motive force. None of the other tested antimicrobials, including macrolides, fluoroquinolones, and β-lactams, had any impact on Nile Red efflux, even at concentrations of up to 1 mM.
In Vitro
Potentiation of Carbapenems with ME1071, a Novel Metallo-β-Lactamase Inhibitor, against Metallo-β-Lactamase- Producing
Pseudomonas aeruginosa
Clinical Isolates
Authors: Ishii Yoshikazu , Eto Maki , Mano Yoko , Tateda Kazuhiro , Yamaguchi Keizo
Published: July 2010

ME1071, a maleic acid derivative, is a novel specific inhibitor for metallo-β-lactamases (MBL). In this study, the potentiation of ME1071 in combination with several β-lactams was evaluated using MBL-producing
Pseudomonas aeruginosa
isolates. The rates of susceptibility of MBL producers to carbapenems (imipenem, biapenem, and doripenem) and ceftazidime were increased by 8 to 27% in the presence of 32 μg/ml of ME1071. The corresponding resistance rates were decreased by 13 to 46%, respectively. On the other hand, ME1071 showed weaker or no potentiation with non-MBL producers. The

K
i

value of ME1071 for IMP-1 was 0.4 μM, significantly lower than the

K
m

values of carbapenems for the IMP-1 enzyme. On the other hand, the

K
i

value of ME1071 for VIM-2 was 120 μM, higher than the

K
m

values of carbapenems for the VIM-2 enzyme. Results of this study indicate that ME1071 can potentiate the activity of ceftazidime and carbapenems against MBL-producing strains of
P. aeruginosa
.
Epidemiology, Treatment, and Prevention of Human T-Cell Leukemia Virus Type 1-Associated Diseases
Authors: Gonçalves Denise Utsch , Proietti Fernando Augusto , Ribas João Gabriel Ramos , Araújo Marcelo Grossi , Pinheiro Sônia Regina , Guedes Antônio Carlos , Carneiro-Proietti Anna Bárbara F.
Published: July 2010

Human T-cell leukemia virus type 1 (HTLV-1), the first human retrovirus to be discovered, is present in diverse regions of the world, where its infection is usually neglected in health care settings and by public health authorities. Since it is usually asymptomatic in the beginning of the infection and disease typically manifests later in life, silent transmission occurs, which is associated with sexual relations, breastfeeding, and blood transfusions. There are no prospects of vaccines, and screening of blood banks and in prenatal care settings is not universal. Therefore, its transmission is active in many areas such as parts of Africa, South and Central America, the Caribbean region, Asia, and Melanesia. It causes serious diseases in humans, including adult T-cell leukemia/lymphoma (ATL) and an incapacitating neurological disease (HTLV-associated myelopathy/tropical spastic paraparesis [HAM/TSP]) besides other afflictions such as uveitis, rheumatic syndromes, and predisposition to helminthic and bacterial infections, among others. These diseases are not curable as yet, and current treatments as well as new perspectives are discussed in the present review.
Community-Associated Methicillin-ResistantStaphylococcus aureus: Epidemiology and Clinical Consequences of an Emerging Epidemic
Authors: David Michael Z. , Daum Robert S.
Published: July 2010

Staphylococcus aureusis an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistantS. aureus(MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.
The Antifungal Activity of the Penicillium chrysogenum Protein PAF Disrupts Calcium Homeostasis in Neurospora crassa
Authors: Binder Ulrike , Chu Meiling , Read Nick D. , Marx Florentine
Published: July 2010

The antifungal protein PAF from
Penicillium chrysogenum
exhibits growth-inhibitory activity against a broad range of filamentous fungi. Evidence from this study suggests that disruption of Ca
2+
signaling/homeostasis plays an important role in the mechanistic basis of PAF as a growth inhibitor. Supplementation of the growth medium with high Ca
2+
concentrations counteracted PAF toxicity toward PAF-sensitive molds. By using a transgenic
Neurospora crassa
strain expressing codon-optimized aequorin, PAF was found to cause a significant increase in the resting level of cytosolic free Ca
2+
([Ca
2+
]
c
). The Ca
2+
signatures in response to stimulation by mechanical perturbation or hypo-osmotic shock were significantly changed in the presence of PAF. BAPTA [bis-(aminophenoxy)-ethane-
N
,
N
,
N
′,
N
′-tetraacetic acid], a Ca
2+
selective chelator, ameliorated the PAF toxicity in growth inhibition assays and counteracted PAF induced perturbation of Ca
2+
homeostasis. These results indicate that extracellular Ca
2+
was the major source of these PAF-induced effects. The L-type Ca
2+
channel blocker diltiazem disrupted Ca
2+
homeostasis in a similar manner to PAF. Diltiazem in combination with PAF acted additively in enhancing growth inhibition and accentuating the change in Ca
2+
signatures in response to external stimuli. Notably, both PAF and diltiazem increased the [Ca
2+
]
c
resting level. However, experiments with an aequorin-expressing Δ
cch-1
deletion strain of
N. crassa
indicated that the L-type Ca
2+
channel CCH-1 was not responsible for the observed PAF-induced elevation of the [Ca
2+
]
c
resting level. This study is the first demonstration of the perturbation of fungal Ca
2+
homeostasis by an antifungal protein from a filamentous ascomycete and provides important new insights into the mode of action of PAF.
Paracoccidioides brasiliensis
Enolase Is a Surface Protein That Binds Plasminogen and Mediates Interaction of Yeast Forms with Host Cells
Authors: Nogueira Sarah Veloso , Fonseca Fernanda L. , Rodrigues Marcio L. , Mundodi Vasanth , Abi-Chacra Erika A. , Winters Michael S. , Alderete John F. , Soares Célia Maria de Almeida
Published: July 2010

Paracoccidioidomycosis (PCM), caused by the dimorphic fungus
Paracoccidioides brasiliensis
, is a disseminated, systemic disorder that involves the lungs and other organs. The ability of the pathogen to interact with host components, including extracellular matrix (ECM) proteins, is essential to further colonization, invasion, and growth. Previously, enolase (EC 4.2.1.11) was characterized as a fibronectin binding protein in
P. brasiliensis
. Interaction of surface-bound enolase with plasminogen has been incriminated in tissue invasion for pathogenesis in several pathogens. In this paper, enolase was expressed in
Escherichia coli
as a recombinant glutathione
S
-transferase (GST) fusion protein (recombinant
P. brasiliensis
enolase [r
Pb
Eno]). The
P. brasiliensis
native enolase (
Pb
Eno) was detected at the fungus surface and cytoplasm by immunofluorescence with an anti-r
Pb
Eno antibody. Immobilized purified r
Pb
Eno bound plasminogen in a specific, concentration-dependent fashion. Both native enolase and r
Pb
Eno activated conversion of plasminogen to plasmin through tissue plasminogen activator. The association between
Pb
Eno and plasminogen was lysine dependent. In competition experiments, purified r
Pb
Eno, in its soluble form, inhibited plasminogen binding to fixed
P. brasiliensis
, suggesting that this interaction required surface-localized
Pb
Eno. Plasminogen-coated
P. brasiliensis
yeast cells were capable of degrading purified fibronectin, providing
in vitro
evidence for the generation of active plasmin on the fungus surface. Exposure of epithelial cells and phagocytes to enolase was associated with an increased expression of surface sites of adhesion. In fact, the association of
P. brasiliensis
with epithelial cells and phagocytes was increased in the presence of r
Pb
Eno. The expression of
Pb
Eno was upregulated in yeast cells derived from mouse-infected tissues. These data indicate that surface-associated
Pb
Eno may contribute to the pathogenesis of
P. brasiliensis
.
Naturally Produced Outer Membrane Vesicles fromPseudomonas aeruginosaElicit a Potent Innate Immune Response via Combined Sensing of Both Lipopolysaccharide and Protein Components
Authors: Ellis Terri N. , Leiman Sara A. , Kuehn Meta J.
Published: July 2010

Pseudomonas aeruginosais a prevalent opportunistic human pathogen that, like other Gram-negative pathogens, secretes outer membrane vesicles. Vesicles are complex entities composed of a subset of envelope lipid and protein components that have been observed to interact with and be internalized by host cells. This study characterized the inflammatory responses to naturally producedP. aeruginosavesicles and determined the contribution of vesicle Toll-like receptor (TLR) ligands and vesicle proteins to that response. Analysis of macrophage responses to purified vesicles by real-time PCR and enzyme-linked immunosorbent assay identified proinflammatory cytokines upregulated by vesicles. Intact vesicles were shown to elicit a profoundly greater inflammatory response than the response to purified lipopolysaccharide (LPS). Both TLR ligands LPS and flagellin contributed to specific vesicle cytokine responses, whereas the CpG DNA content of vesicles did not. Neutralization of LPS sensing demonstrated that macrophage responses to the protein composition of vesicles required the adjuvantlike activity of LPS to elicit strain specific responses. Protease treatment to remove proteins from the vesicle surface resulted in decreased interleukin-6 and tumor necrosis factor alpha production, indicating that the production of these specific cytokines may be linked to macrophage recognition of vesicle proteins. Confocal microscopy of vesicle uptake by macrophages revealed that vesicle LPS allows for binding to macrophage surfaces, whereas vesicle protein content is required for internalization. These data demonstrate that macrophage sensing of both LPS and protein components of outer membrane vesicles combine to produce a bacterial strain-specific response that is distinct from those triggered by individual, purified vesicle components.
Phylogenetic Analysis ofChlamydia trachomatisTarp and Correlation with Clinical Phenotype
Authors: Lutter Erika I. , Bonner Christine , Holland Martin J. , Suchland Robert J. , Stamm Walter E. , Jewett Travis J. , McClarty Grant , Hackstadt Ted
Published: July 2010

Chlamydia trachomatisis the leading cause of infectious blindness worldwide and is the most commonly reported pathogen causing sexually transmitted infections. Tarp (translocated actin recruiting phosphoprotein), a type III secreted effector that mediates actin nucleation, is central toC. trachomatisinfection. The phylogenetic analysis oftarPfrom reference strains as well as ocular, genital, and lymphogranuloma venereum (LGV) clinical isolates demonstrated an evolutionary relationship with disease phenotype, with LGV and ocular isolates branched into clades that were separate from the urogenital isolates. The sequence analysis of Tarp indicated a high degree of variability and identified trends within clinical groupings. Tarps from LGV strains contained the highest number of tyrosine-rich repeat regions (up to nine) and the fewest (two) predicted actin binding domains. The converse was noted for Tarp proteins from ocular isolates that contained up to four actin binding domains and as few as one tyrosine-rich repeat region. The results suggest that Tarp is among the few known genes to play a role inC. trachomatisadaptations to specific niches within the host.
Tenocyte hypercellularity and vascular proliferation in a rabbit model of tendinopathy: contralateral effects suggest the involvement of central neuronal mechanisms
Authors: Andersson Gustav , Forsgren Sture , Scott Alexander , Gaida James Edmund , Stjernfeldt Johanna Elgestad , Lorentzon Ronny , Alfredson Håkan , Backman Clas , Danielson Patrik
Published: July 2010

Objective

To determine whether there are objective findings of tendinosis in a rabbit tendinopathy model on exercised and contralateral (non-exercised) Achilles tendons.

Design

Four groups of six New Zealand white rabbits per group were used. The animals of one (control) group were not subjected to exercise/stimulation.

Interventions

Animals were subjected to a protocol of electrical stimulation and passive flexion–extension of the right triceps surae muscle every second day for 1, 3 or 6 weeks.

Main Outcome Measures

Tenocyte number and vascular density were calculated. Morphological evaluations were also performed as well as in-situ hybridisation for vascular endothelial growth factor (VEGF) messenger RNA.

Results

There was a significant increase in the tenocyte number after 3 and 6 weeks of exercise, but not after 1 week, in comparison with the control group. This was seen in the Achilles tendons of both legs in experimental animals, including the unexercised limb. The pattern of vascularity showed an increase in the number of tendon blood vessels in rabbits that had exercised for 3 weeks or more, compared with those who had exercised for 1 week or not at all. VEGF-mRNA was detected in the investigated tissue, with the reactions being more clearly detected in the tendon tissue with tendinosis-like changes (6-week rabbits) than in the normal tendon tissue (control rabbits).

Conclusions

There were bilateral tendinosis-like changes in the Achilles tendons of rabbits in the current model after 3 weeks of training, suggesting that central neuronal mechanisms may be involved and that the contralateral side is not appropriate as a control.
Significance of “gneissic” rocks in the Liscomb Complex, Nova Scotia
Authors: Owen J. V. , Corney R. , Dostal J. , Vaughan A.
Published: July 2010

The Liscomb Complex comprises Late Devonian intrusive rocks (principally peraluminous granite) and medium- to high-grade metamorphic rocks (“gneisses”) that collectively are hosted by low-grade (greenschist facies) metasediments of the Cambro-Ordovician Meguma Group. The conventional view that these “gneisses” contain high-grade mineral assemblages and represent basement rocks has recently been challenged, and indeed, some of the rocks previously mapped as gneisses, particularly metapelites, have isotopic compositions resembling the Meguma Group. Amphibole-bearing enclaves in the Liscomb plutons, however, are isotopically distinct and in this regard resemble xenoliths of basement gneisses in the Popes Harbour lamprophyre dyke, south of the Liscomb area. Metasedimentary enclaves with Meguma isotopic signatures can contain garnets with unzoned cores (implying high temperatures) that host high-grade minerals (prismatic sillimanite, spinel, and (or) corundum) and are enclosed by retrograde-zoned rims. These features are interpreted here as having formed during and following the attainment of peak temperatures related to Liscomb magmatism. The amphibole-bearing meta-igneous rocks described here contain cummingtonite or hornblendic amphibole and occur as enclaves in granodioritic to tonalitic plutons. They are mineralogically, texturally, and isotopically distinct from Meguma metasediments and at least some of the plutonic rocks that enclose them, so remain the most likely candidate for basement rocks in the Liscomb Complex.
Population-specific locomotor phenotypes are displayed by barramundi, Lates calcarifer, in response to thermal stress
Authors: Edmunds Richard C. , van Herwerden Lynne , Fulton Christopher J.
Published: July 2010

We investigated how thermal stress may alter the locomotor phenotype of barramundi, Lates calcarifer , from genetically distinct northern (low latitude) and southern (high latitude) populations in tropical Australia. Following early growth and development under native (25 °C and 30 °C) and non-native (20 °C and 35 °C) temperatures, we observed distinct differences in the swimming performance of northern and southern individuals that were consistent with expectations based on local thermal adaptation. Southern population fish exhibited significantly faster swimming speeds (32.10 ± 0.33 cm·s–1, mass-adjusted mean ± 95% confidence limit) than their northern counterparts (28.58 ± 0.64 cm·s–1) under cold-stress (20 °C) conditions. Conversely, northern population fish performed significantly better (51.63 ± 2.1 cm·s–1) than their southern counterparts (44.18 ± 3.11 cm·s–1) under heat-stress (35 °C) conditions. We conclude that L. calcarifer display locomotor phenotypes thermally adapted to their local environment, with early growth under non-native temperatures leading to significantly reduced phenotypic fitness.
Modelling fishing-induced adaptations and consequences for natural mortality
Authors: Jørgensen Christian , Fiksen Øyvind
Published: July 2010

When trade-offs involving predation and mortality are perturbed by human activities, behaviour and life histories are expected to change, with consequences for natural mortality rates. We present a general life history model for fish in which three common relationships link natural mortality to life history traits and behaviour. First, survival increases with body size. Second, survival declines with growth rate due to risks involved with resource acquisition and allocation. Third, fish that invest heavily in reproduction suffer from decreased survival due to costly reproductive behaviour or morphology that makes escapes from predators less successful. The model predicts increased natural mortality rate as an adaptive response to harvesting. This extends previous models that have shown that harvesting may cause smaller body size, higher growth rates, and higher investment in reproduction. The predicted increase in natural mortality is roughly half the fishing mortality over a wide range of harvest levels and parameter combinations such that fishing two fish kills three after evolutionary adaptations have taken place.
Do riparian zones qualify as critical habitat for endangered freshwater fishes?
Authors: Richardson John S. , Taylor Eric , Schluter Dolph , Pearson Mike , Hatfield Todd
Published: July 2010

Identification of critical habitat is a key step in conservation and recovery of endangered and threatened freshwater fish. Critical habitat under Canadian and US legislation may include habitat that is not directly used by listed fish, provided it is necessary for species conservation or recovery. Riparian habitat meets biological criteria for critical habitat because riparian zones are integral to aquatic ecosystem functions of importance to many fish species and other organisms. These functions include provision of shade for temperature-sensitive species, control of channel complexity and sediment inputs through bank stabilization, input of large wood and allochthonous energy sources, and filtering of nutrients and toxins from adjacent land. In response to decades of stream-riparian research, widespread implementation of regulations to protect riparian zones in most developed countries represent a de facto consensus that riparian buffers are essential for aquatic ecosystem health and the maintenance of populations of fish and other species. Consistent with widespread riparian regulations deemed necessary to protect not-at-risk species, riparian habitat adjacent to a body of water containing a listed freshwater species should be considered biologically critical unless the habitat requirements of individual taxa are demonstrated to be insensitive to the ecological functions associated with riparian habitat.
Characterization of Norwegian marine clays with combined shear wave velocity and piezocone cone penetration test (CPTU) data
Authors: Long Michael , Donohue Shane
Published: July 2010

A database of research-quality piezocone cone penetration test (CPTU) and shear wave velocity, Vs, information for Norwegian marine clays has been assembled to study the small-strain stiffness relationships for these materials and to examine the potential use of CPTU and Vs data in combination for the purposes of characterizing these soils. Data for sites where high-quality block sampling was carried out have mostly been used. Improvements have been suggested to existing correlations between the small-strain shear modulus, Gmax, or Vs and index properties for these soils. Recent research has shown that CPTU corrected cone tip resistance, qt, and especially the pore pressure measured during CPTUs, u2, and Vs can be measured reliably and repeatably and are not operator or equipment dependant. Therefore, a new soil classification chart involving the normalized cone resistance, Qt, and normalized shear wave velocity, Vs1, or Vs1 and Δu/[Formula: see text] (where u is the pore-water pressure and [Formula: see text] is the in situ vertical effective stress) is presented. Using this chart it is possible to clearly distinguish between clays of different overconsolidation ratios (OCRs).
The mechanics of subglacial sediment: an example of new “transitional” behaviour
Authors: Altuhafi Fatin , Baudet Béatrice A. , Sammonds Peter
Published: July 2010

A series of isotropic compression tests and drained and undrained triaxial compression tests have been performed on glacial sediment from Iceland. Langjökull sediment, which is well graded, is thought to have reached a critical grading during deposition and transportation. Multiple parallel normal compression lines (NCLs) were found, but a unique critical state line (CSL) could be identified. This is unlike other so-called “transitional” soils, whose grading varies between reasonably well graded to gap graded, which tend to have distinct NCLs and critical state lines depending on the specimen density. It is thought that in the case of the Langjökull sediment studied, its particular strain history that involved incessant shearing during deposition accounts for the difference in behaviour. This provides the interesting case of a soil that has been crushed to a critical grading in situ, which depends on the mineralogy of the grains, which was then sampled and tested. Despite the unique grading, samples with a range of different void ratios can be prepared and the combination of grading and density seems to set a fabric that cannot be changed by compression, resulting in multiple parallel NCLs. At the critical state, however, the fabric has been destroyed and the CSL is unique.
A simple model for the effect on soil strength of episodes of remoulding and reconsolidation
Authors: White David J. , Hodder Matt
Published: July 2010

Many geotechnical processes related to offshore foundations and pipelines on clay soils involve intermittent episodes of remoulding and reconsolidation. To assess the resulting response, it is necessary to predict the operative soil strength, which decreases due to remoulding but can increase due to reconsolidation. A simple framework that allows these processes to be linked, via concepts from critical state soil mechanics, is described. The framework is illustrated by back-analysing a T-bar penetrometer test that involved episodes of both remoulding and reconsolidation, which was conducted in a geotechnical centrifuge. It is shown that the model can capture the surprising increases in both the intact and the remoulded strength that are observed between episodes of remoulding.
Synthesis and characterization of chalcone-substituted phosphazenes
Authors: Ngaini Zainab , Abdul Rahman Norashikin I.
Published: July 2010

A series of mono[(E)-1-(4-alkyloxyphenyl)-3-(4-hydroxy-phenyl)prop-2-en-1-one]cyclotriphosphazenes and hexakis[(E)-1-(4-alkyloxy-phenyl)-3-(4-hydroxy-phenyl) prop-2-en-1-one]cylotriphosphazenes have been synthesized. A convenient synthetic method was performed from the reaction of hexachlorocyclotriphosphazenes with 1 and 6 equiv. of (E)-1-(4-alkyloxyphenyl)-3-(4-hydroxy-phenyl)prop-2-en-1-one (2a–2c) to afford (3a–3c) in 17%–19% and (4a–4c) in 70%–82%, respectively. The compounds differ in the length of alkyl groups, CnH2n+1, where n = 10, 12, and 14.
Electrochemical reduction of sunset yellow at a multiwalled carbon nanotube (MWCNT)-modified glassy carbon electrode and its analytical application
Authors: Song Yuan-Zhi
Published: July 2010

The electrochemical reduction of sunset yellow at a multiwalled carbon nanotube (MWCNT)-modified glassy carbon electrode is investigated using cyclic voltammetry. A simple, sensitive, and inexpensive method for determination of sunset yellow in soft drinks is proposed and the accuracy and reproducibility of this determination method are evaluated. This method is satisfactorily applied for the determination of sunset yellow in soft drinks in the concentration range of 1.2–125.0 mg L–1 and 125.0–265.0 mg L–1, with a detection limit of 0.5 mg L–1.
Étude DFT des réactions d’hydrogénation des cyclohéxènes disubstitués en position 2 et 3
Authors: Ayadi Sameh , Abderrabba Manef
Published: July 2010

Dans ce travail, nous avons étudié théoriquement les réactions d’hydrogénation des cyclohéxènes disubstitués par une voie chimique par le (Z)-1,2-diazène (1) et le (E)-1,2-diazène (1′). Nous avons discuté de point de vue thermodynamique la possibilité et la stéréosélectivité de ces réactions. Les états de transition de la réaction entre les cyclohéxènes de type (2a–2c) et le (Z)-1,2-diazène (1) ont été déterminés.
Chemical Composition of Stemflow from Some Eastern Canadian Tree Species
Authors: Mahendrappa M. K.
Published: July 2010

Stemflow samples from three hardwood and six softwood species were collected during May through October and concentrated by the freeze-concentration method and then freeze-dried. Liquid samples were used for pH determinations and the freeze-dried materials were analyzed for carbohydrates; carbon, hydrogen, nitrogen, and oxygen of the organic fraction; and calcium, magnesium, sodium, potassium, and iron of the inorganic constituents.In comparison with hardwoods, the stemflow from softwoods was more acidic and contained larger concentrations of total solids (organic + inorganic constituents).Except for nitrogen, which was present in larger proportions in hardwood than in softwood stemflow, there was no distinct difference in the composition of other constituents of the organic fraction. Concentrations of cations in the stemflow from the majority of the species decreased in the order of potassium, calcium, sodium, and magnesium. Only potassium and carbohydrates were returned to the soil in kilogram quantities per hectare whereas the other nutrients were returned in amounts less than 1 kg/ha.
Nonlinear Models for Stand Table Projection in Northern Hardwood Stands
Authors: Ek Alan R.
Published: July 2010

Nonlinear equation models were developed for prediction of periodic ingrowth, mortality, and survivor growth by 2-in. (5.1-cm) diameter classes in northern hardwood stands. Equations were constructed using 5 year growth records on 132 plots from stands with a broad range of age and size class distributions. The model for number of ingrowth trees in the smallest diameter class measured was [Formula: see text] where G and N are initial stand basal area and number of trees, respectively, on a per acre basis and the bi's are constants. Mortality in a diameter class expressed as trees per acre was described by the model [Formula: see text] where g and n indicate initial basal area and number of trees in a specified diameter class. Survivor growth was described by prediction of the number of trees in a class which grow into the next larger size class during the growth period. The model for the number of stems moving up was [Formula: see text] where S is a site class term. Considerations in the formulation of the models and a discussion of their utility and limitations are also presented.
Water Level Fluctuation in a Northeastern Ontario Peatland
Authors: Dai T. S. , Haavisto V. F. , Sparling J. H.
Published: July 2010

Depths to water level and changes due to local climate were dissimilar in five peatland conditions in northeastern Ontario. The deepest water level and the greatest fluctuations occurred in an ombrotrophic black spruce bog site. The sedge-dominated poor fen site was submerged following every heavy rain. Waterlogged conditions remained within 6 cm of the surface at all times because of the influence by the water level of Dai Lake. The water level of Dai Lake varied within a narrow range because the loss of water was primarily dependent on slow seepage and evaporation. The lagg site was affected by continuous inflow, high water levels, and fast run-off, therefore, a larger fluctuation of water level prevailed at this site.
Snow Damage to Branches of Young Red Pine Stands Related to Plantation Density
Authors: Neary Daniel G. , Day Maurice W. , Schneider G.
Published: July 2010

Snow damage was measured in a 9-year-old northern Michigan red pine (Pinusresinosa) plantation following three severe winters. Snow related injury was usually in the form of complete branch breakage or partially severed lateral branches. Densities of 2000 trees/ha suffered three to four times more damage as those with 500 trees/ha.Injury was primarily concentrated at about 75 cm above the ground, a height reflecting snow depth. This corresponded to the location of the fourth whorl where branch injury was twice as extensive in plots with 1000, 1500, and 2000 trees/ha as those with 500 or 750 trees/ha.Although few trees have as yet died from this snow damage, many have been severely weakened and are thus predisposed to insect attack, disease infestation, and further mechanical injury.
Chemical and Environmental Treatments Promoting Rooting of Pine Cuttings
Authors: Hare R. C.
Published: July 2010

Cuttings from older pines rooted more abundantly and rapidly in a growth chamber than in a greenhouse. Numerous rooting powder formulations were tested, and those containing auxins, sucrose, a fungicide, and a growth retardant outperformed those lacking one or more of these components. Best treatment combinations gave 83% rooting of cuttings from 13-year-old shortleaf pine (Pinusechinata Mill.) in 12 weeks, 100% rooting of cuttings from 12-year-old Japanese black pine (P. thunbergiana Franco) in 8 weeks, and 100% rooting of cuttings from 1-year-old slash pine (P. elliottii var. elliottii Engelm.) in 6 weeks. The most effective powder contained 1% each of indolebutyric acid, 1-phenyl-3-methyl-5-pyrazolone, and N-dimethylaminosuccinamic acid, plus 10% each of powdered sucrose and captan.
A Study of Tree Root Strength Deterioration Following Clearfelling
Authors: O'Loughlin C. L.
Published: July 2010

The tensile strengths of Douglas fir and western red cedar roots growing in landslide-susceptible mountain soils in coastal British Columbia were measured in the laboratory. Tests on small roots, between 1 and 12 mm in diameter, sampled from living trees and from dead stumps cut at various times in the past, showed that Douglas fir and cedar roots rapidly lose their tensile strength after death of the parent tree. Within 3–5 years after felling of the parent tree small roots may lose over half their original tensile strength.
A CLASS OF POVERTY MEASURES INDUCED BY THE DUAL DECOMPOSITION OF AGGREGATION FUNCTIONS
Authors: GARCÍA-LAPRESTA JOSÉ LUIS , DE LA VEGA CASILDA LASSO , MARQUES PEREIRA RICARDO ALBERTO , URRUTIA ANA MARTA
Published: July 2010

In this paper we introduce a new family of poverty measures for comparing and ordering social situations. The aggregation scheme of these poverty measures is based on the one-parameter family of exponential means. The poverty measures introduced satisfy interesting properties and the dual decomposition of the underlying exponential means induces a natural decomposition of the proposed poverty indices themselves into three underlying factors: incidence, intensity, and inequality among the poor.
FABRICATION AND MEASUREMENT OF SUSPENDED SILICON CARBIDE NANOWIRE DEVICES AND DEFLECTION
Authors: JUNG INHWA , CHUNG JAE-HYUN , PINER RICHARD , SUK JI WON , RUOFF RODNEY S.
Published: July 2010

In this paper, we report the measurement of the deflection of β- SiC nanowires supported at both ends. Such wires hold promise as active elements in NEMS/MEMS devices. To ensure the stable mechanical clamping and electrical contacts between electrodes and nanowires, we have developed a method of metal deposition to improve the contacts. This method consists of multiple depositions at different angles in order to avoid the shadow effect and reduce the compressive residual stress. The improvement of the contacts was verified via SEM observation and electrical transport measurements. To suspend the nanowire, a dielectric layer underneath was removed, followed by critical point drying. The change of electrical resistance was measured when the suspended nanowires were deflected by either capillary forces arising from the surface tension or electrostatic forces.
ON THE BRAIDED MONOIDAL CATEGORY OF W-SMASH COPRODUCT COMODULE
Authors: Dong Lihong , Jiao Zhengming
Published: July 2010

In this paper, we discuss the W-smash coproduct comodule category [Formula: see text] and give the necessary and sufficient conditions for the W-smash coproduct comodule category [Formula: see text] to be a braided monoidal category.
RINGS WITH LEFT MULTIPLICATIVE IDENTITIES
Authors: Ghosseiri Nader M.
Published: July 2010

In this paper we introduce the notion of left multiplicative identities for rings and prove some properties of such rings.