bluuebunny/crossref_metadata_2025 huggingface dataset:
Weight Optimization of Stiffened Cylindrical Panels
Authors: McGrattan R. J.
Published: November 2009

Many structures have curved panels with longitudinal, transverse, or orthogonal tee-stiffeners subjected to differential pressure, band loading, and axial and circumferential in-plane forces. Equations using energy methods are developed for the purpose of designing such cylindrical structures for minimum weight. The accuracy of the techniques is verified by excellent stress comparisons with finite-element methods. Minimum weight studies using a constrained optimization computer program are presented. Stress, deflection, stability, and minimum dimensional constraints are applied. Optimum weight designs are achieved rapidly and economically.
Selection of Degrees of Freedom for Dynamic Analysis
Authors: Matta K. W.
Published: November 2009

A technique for the selection of dynamic degrees of freedom (DDOF) of large, complex structures for dynamic analysis is described and the formulation of Ritz basis vectors for static condensation and component mode synthesis is presented. Generally, the selection of DDOF is left to the judgment of engineers. For large, complex structures, however, a danger of poor or improper selection of DDOF exists. An improper selection may result in singularity of the eigenvalue problem, or in missing some of the lower frequencies. This technique can be used to select the DDOF to reduce the size of large eigenproblems and to select the DDOF to eliminate the singularities of the assembled eigenproblem of component mode synthesis. The execution of this technique is discussed in this paper. Examples are given for using this technique in conjunction with a general purpose finite element computer program GENSAM[1].
Valve Stroking to Control Water Hammer Transients Using Dynamic Programming
Authors: Contractor D. N.
Published: November 2009

Fluid transients in a pipeline caused by valve operation can be minimized by operating the valve in an optimally prescribed manner, in a given time of closure (tc > 2L/a). Dynamic programming is used to select the operation of the valve (i.e., set the valve-operating policy) over the time period tc so that the pressure rise at the valve (the objective function) is minimized. Constraints on the valve closure policy may also be specified, e.g., monotonic valve closure. Application of this method to a simple pipeline with a reservoir at one end and a valve at the other end shows that the pressure rise at the valve is lower than when the valve is closed linearly with time. The benefits of dynamic programming are shown to be greatest when the time of closure tc is small. The method has also been applied to valve opening, so that the pressure drop at the valve is a minimum.
Acoustic Resonance in Heat Exchanger Tube Bundles—Part I: Physical Nature of the Phenomenon
Authors: Blevins R. D. , Bressler M. M.
Published: November 2009

The intense acoustic resonance resulting from gas flow across a bank of heat exchanger tubes in a duct has been investigated experimentally and theoretically. At low gas velocities, the acoustic tone emanating from tube bundles increases in proportion to the flow velocity. When the frequency approaches a bound acoustic transverse mode of the tube bundle, intense sound can result. Sound levels as high as 173 db were measured within the bundle. During resonance, the sound correlates vortex shedding from the tubes and the pressure drop increases in some bundles.
Stress Analysis of Elliptical Tube Plates in Heat Exchangers
Authors: Sang Zhi-Fu , Widera G. E. O.
Published: November 2009

Elliptical tube plates are used widely in high temperature, high pressure heat exchangers and waste heat boilers. This paper presents a detailed analysis of the stress distribution in elliptical tube plates subjected to internal pressure and discusses the location of the maximum stress. Two test models were used to gather data. Calculations were based on two-dimensional finite element analysis. The experiments used strain gage measurements. The results of the analysis of the two models show that the theoretical calculations and the experimental data are in good agreement, and that the location of the maximum stress is not at the crown of the elliptical tube plates. The latter result differs from the previously published conclusions of Rachkov and Morozov [1].
Primary Creep Analysis of an Anisotropic Thick-Walled Spherical Shell
Authors: Bhatnagar N. S. , Kularni Pradnya , Arya V. K.
Published: November 2009

The problem of primary creep of an orthotropic thick-walled spherical shell under internal pressure has been analyzed in this paper. The creep stresses and strains have been calculated using a method of successive approximations. All results have been obtained in nondimensional form. Effect of anisotropy on stresses and strain rates is discussed.
An Analytical Model of Strength Loss in Filament Wound Spherical Vessels
Authors: Leavesley P. J. , Knight C. E.
Published: November 2009

The potential strength degradation of a filament wound sphere was predicted using an incremental finite element model of the composite during fabrication. The sphere was modeled taking into account the winding pattern and the resulting internal layer boundaries. The thickness profile of the sphere’s layers were computed using a pattern simulation program. The total thickness profile and layer thickness profiles were used by the mesh generating program to ensure that the elements generated matched layer boundaries. The elements were isoparametric quadrilaterals which were collapsed to triangular elements for transitions. The main feature of the finite element program was the incremental construction and loading of the model to simulate the winding process. Strength degradation definitely occurs when the average fiber strain in any layer is negative. The negative strain means that all the winding tension has been lost from the layer, and the imposition of compressive strain causes fibers in uncured resin to wrinkle or buckle. Then when the resin cures the buckled region of fibers are degraded in strength. An analysis of a Kevlar/epoxy sphere demonstrated that strength degradation could occur. The innermost layers showed significant tension loss and compressive strain during fabrication which would produce strength degradation. The model sphere was a typical thick wall construction using normal processing conditions.
On Some Performance Parameters for Closed Feedwater Heaters
Authors: Singh K. P.
Published: November 2009

This paper gives a brief synopsis of the thermo-dynamic imperative of the feedwater heater in the power cycle, followed by the development of two performance parameters. These two parameters, the “Flash Protection Index” (FPI) and the “Heater Time Constant,” are closely linked to the heater thermal/hydraulic performance, and can be used to avert operational problems by identifying them at the design stage. Finally, a method to size the vapor suppression plate for feedwater heaters is also presented.
Strouhal Numbers for Heat Exchanger Tube Arrays in Cross Flow
Authors: Weaver D. S. , Fitzpatrick J. A. , ElKashlan M.
Published: November 2009

The prediction of tube or acoustic resonance due to cross-flow in heat exchangers is dependent upon knowledge of the flow characteristics for a given tube array geometry. For this, a Strouhal number relating a peak frequency in the turbulence spectrum to the velocity of the flow is required. The data available in the literature for this are rather confusing and the prediction methods appear somewhat contradictory. This paper reports the results from experiments conducted to determine Strouhal numbers for eight tube array models. These results together with the data available in the literature are then compared and appropriate conclusions drawn.
Collapse Characteristics of a Thin-Walled Elbow: Validation of an Analytical Procedure
Authors: Dhalla A. K.
Published: November 2009

A nonlinear analysis procedure is validated in this paper to predict deformation response, up to collapse, of thin-walled Liquid Metal Reactor (LMR) piping elbows. Nonlinear shell analysis predictions are compared with experimental measurements of two full-scale large diameter (406 mm), thin-walled (D/t = 38), piping elbows tested at room temperature and at an elevated temperature in the Multi-Load Test Facility (MLTF) at Westinghouse. The overall and local deformation predictions agree very well with the measured deformation responses up to 60 percent of the measured plastic collapse moment, Mpce. The analytical-experimental correlation is reasonable up to 0.8 Mpce. At higher load levels the correlation is not as good; at collapse the analysis overpredicts measured deformations by as much as 30 percent.
Notch Ductility Requirements of Line Pipes for Arresting Propagating Shear Fracture
Authors: Sugie E. , Matsuoka M. , Akiyama T. , Tanaka K. , Kawaguchi Y.
Published: November 2009

Full-scale burst tests were carried out on X70 line pipes, 48 in. o. d. × 0.720 in. w. t., with air and rich and natural gas as the pressurizing gases. The experimental results indicated that very high notch ductilities of pipes are required for arresting propagating shear fracture especially in the case of the rich natural gas. From theoretical investigations a method was developed which enabled the prediction of the required notch ductilities of line pipes with regard to the type of gas, design stress and acceptable fracture length.
Experimental Verification of Fracture Toughness Requirement for Leak-Before-Break Performance for 155–175 ksi Strength Level Gas Cylinders
Authors: Rana M. D.
Published: November 2009

This paper deals with a determination of the fracture toughness requirement to obtain leak-before-break performance for a 155–175 ksi strength level high-pressure gas cylinder. Analytical LEFM methods along with Irwin’s KIc-Kc equation related by the parameter βIc were used to predict the fracture toughness requirement for the plane-stress fracture state problem. Experimental work was conducted on flawed cylinders to quantify the fracture toughness requirement for leak-before-break performance. The results indicated that the analytically predicted toughness requirement is 4 to 25 percent higher than that established experimentally. The results also indicated that the minimum specified KIc(J) value of 85 ksi in. (93.5 MPam) for the gas cylinder is sufficiently higher than the analytically and experimentally established toughness values to provide the desired leak-before-break performance.
A Theoretical Assessment of Napier’s Law
Authors: Candau Y.
Published: November 2009

Napier’s Law is advantageous for calculating critical mass flow rate of water-steam mixture. On the basis of numerical computations, it has been recently extended to a number of fluids. A theoretical approach using simple thermodynamic calculations can account for the existence of such a law when a few basic conditions are fulfilled.
Experimental Tests for Suppression Effects of Water Restraint Plates on Sloshing of a Water Pool
Authors: Muto K. , Kasai Y. , Nakahara M.
Published: November 2009

Forced vibration tests for a spent fuel storage pool of nuclear facilities [1] were conducted for the purpose of determining sloshing suppression effects. The devices reported in this paper are cantilever-type water restraint plates. They reduce sloshing and also prevent overflow of water from the pool. Parameters examined in the experimental tests were the installation height levels, lengths and shapes of the water restraint plates. The most effective installation conditions of these water restraint plates were found through the tests.
Effect of Imperfect Contact Between Adjacent Layers on the Integrity of Wrapped Vessels
Authors: Rasty J. , Sabbaghian M.
Published: November 2009

Multilayer vessels are the designer’s solution to the inefficiency involved in operating monoblock vessels at pressures above 50 MPa. Multilayer wrapped vessels are commonly employed in high-pressure applications of up to 550 MPa. They are advantageous to monoblock cylindrical construction in several aspects, one of which is the prestressing of the layers in order to more efficiently distribute the stresses developed due to the inside pressure. Calculation of prestress in each layer, due to shrinkage of the weld, has been reported before. Nearly all such reports are based on the assumption that layers are in perfect contact with one another. In practice, however, occasions may arise, where due to imperfect rolling and/or variations in the thickness of a plate, there remains an isolated local gap between adjacent layers. In this investigation, the size of a gap is defined in terms of its circumferential arc length and maximum radial height. The effects of imperfect contact on prestresses are obtained, in terms of the size of the gap, by calculating the stresses sustained by the layer in order to bring the layer in perfect contact with the next layer. The foregoing task is achieved by deriving expressions for the stresses due to the closure of a gap as well as analysis by finite element approach. A method is proposed to calculate, for a given size gap, the necessary reduction in operating pressure in order to maintain the original factor of safety. Inversely, if the vessel must operate at the original design pressure, one can calculate the maximum allowable size of a gap (for a given percent reduction in factor of safety or strength) that would not affect the integrity of the vessel.
Effects of Plasticity on Dynamic Response of Piping Structures
Authors: Lazzeri L.
Published: November 2009

The analysis of elastoplastic structures under a combination of static and dynamic loads is examined. It is shown that under the hypothesis of a ductile behavior, progressive distortion is the leading failure mechanism. Procedures are described to compute: (a) the equivalent damping due to hysteretic losses; (b) frequency shifting due to structural softening in the plastic fields; (c) ductility effects on dynamic loads; and (d) ratcheting due to a combination of static and dynamic loads.
J-Estimation Procedure Based on Moire Interferometry Data
Authors: Kang B. S. J. , Kobayashi A. S.
Published: November 2009

The accuracy of the approximate J-estimation procedure evaluated along rectangular contours in the elastic and the HRR crack tip fields was assessed. The path independency of the approximate J’s in the presence of LEFM and elastic-plastic stress fields was demonstrated experimentally in 7075-T6, 2024-0 and 5052–H32 SEN specimens with small stable crack growth of 1 to 2 mm. HRR field does not exist in a ductile material with relatively large strain-hardening exponent, i.e., N = 15. The approximate J and the COD resistance curves for 2024-0 and 5052-H32 specimens for small crack extension was established. These curves showed little sensitivity to the notch tip acuity due to large plastic yielding.
Fatigue and Creep-Fatigue Testing of Bellows at Elevated Temperature
Authors: Yamamoto S. , Isobe K. , Ohte S. , Tanaka N. , Ozaki S. , Kimura K.
Published: November 2009

Fatigue and creep-fatigue tests at elevated temperature were conducted on two different-sized bellows, φ 1100 mm and φ 300 mm in nominal inner diameter, to investigate the fatigue life and the creep-fatigue interaction in a bellows, and also to provide test data for developing a life prediction method and design-by-analysis rules for bellows in elevated temperature service. A series of tests consisted of strain behavior and fatigue tests at room temperature, and fatigue and creep-fatigue tests at elevated temperature. Also, inelastic finite element analyses were performed on a bellows under internal pressure and cyclic axial deflections. Analytical results were compared with the measured data obtained in the room temperature testing to verify the strain prediction method.
Design and Life Prediction of Fired Heater Tubes in the Creep Range
Authors: Seshadri R.
Published: November 2009

Realistic fired heater tube-life predictions are essential to safe and economical design, proactive inspection strategy and meaningful tube retirement evaluations. The traditional method of heater tube design (API RP 530), that is based on the “mean-diameter equation,” sometimes implies tube-life in excess of actual operating experience. The main reason for this discrepancy is the interaction of cyclic radial thermal gradient, that exists across the tube wall, with the pressure-induced stresses resulting in enhanced creep damage. Upper-bound estimates for creep deformations and creep damage are obtained in this paper using a simple analytical procedure. Some broad guidelines relating to the assessment of remaining tube-life, tube retirement and inspection frequencies are presented.
Finite and Infinitesimal Damage: Study of Evolution and Experimental Simulation
Authors: Dragon A. , Desoyer T.
Published: November 2009

The damage-related internal variables are introduced as associated with kinematical (deformation) measures. Two basic damage tensors relative to finite damage are defined through macro-micro transition for the Lagrangian velocity gradient and the Eulerian one. Both reduce to a small-damage tensor as the finite deformation measures reduce to their common infinitesimal strain counterpart. The damage mechanism by cavity growth from hard inclusions is examined. The systematic procedure is proposed to settle up the damage evolution equation. It is based on the datum of the local velocity field within an elementary cell viewed as an element containing an inner cavity and subject to displacement boundary conditions compatible with homogeneous deformation of outer faces. Experimental procedure is employed to verify the hypotheses regarding the local velocity field in the cell and evolutive cavity forms in a two-dimensional case. Artificial cylindrical inclusions are embedded in a metal plate, periodicity of their spacing being respected. The laser-speckle measurements of displacement increments are performed within a unit-cell chosen as the whole element is loaded to plasticity range. They permit to evaluate the “local” smoothed velocity field perturbed by cavity presence.
Design Criteria for Boilers and Pressure Vessels in the U.S.A.
Authors: Bernstein Martin D.
Published: November 2009

Preface. Code criteria defined. Evolution of ASME Boiler and Pressure Vessel Code. How the Code operates today. Design by rule. Evolution of design by analysis. Types of stress and their significance. Failure modes. Strength theories. Design loads. New or unusual designs. Code Cases. Interpretations. Stress limits for design by rule and design by analysis. Elevated temperature design. Recent developments. A glimpse at the future. References.
Towards Automated Nanoassembly With the Atomic Force Microscope: A Versatile Drift Compensation Procedure
Authors: Krohs Florian , Onal Cagdas , Sitti Metin , Fatikow Sergej
Published: November 2009

While the atomic force microscope (AFM) was mainly developed to image the topography of a sample, it has been discovered as a powerful tool also for nanomanipulation applications within the last decade. A variety of different manipulation types exists, ranging from dip-pen and mechanical lithography to assembly of nano-objects such as carbon nanotubes (CNTs), deoxyribonucleic acid (DNA) strains, or nanospheres. The latter, the assembly of nano-objects, is a very promising technique for prototyping nanoelectronical devices that are composed of DNA-based nanowires, CNTs, etc. But, pushing nano-objects in the order of a few nanometers nowadays remains a very challenging, labor-intensive task that requires frequent human intervention. To increase throughput of AFM-based nanomanipulation, automation can be considered as a long-term goal. However, automation is impeded by spatial uncertainties existing in every AFM system. This article focuses on thermal drift, which is a crucial error source for automating AFM-based nanoassembly, since it implies a varying, spatial displacement between AFM probe and sample. A novel, versatile drift estimation method based on Monte Carlo localization is presented and experimental results obtained on different AFM systems illustrate that the developed algorithm is able to estimate thermal drift inside an AFM reliably even with highly unstructured samples and inside inhomogeneous environments.
Bacterial Trigger of Plant Protection
Authors: Hines Pamela
Published: November 2009

The bacterial trigger for a rice innate immune response is identified.
The Death of Cocco
Authors: Ash Caroline
Published: November 2009

A specific virus encodes membrane components that broadcast cell death and population demise of its coccolithophore host.
Novel VIM Metallo-β-Lactamase Variant from Clinical Isolates of
Enterobacteriaceae
from Algeria
Authors: Robin Frédéric , Aggoune-Khinache Nadjet , Delmas Julien , Naim Malek , Bonnet Richard
Published: November 2009

Five different strains of bacteria belonging to the family
Enterobacteriaceae
were isolated from two patients hospitalized in the intensive care unit of the Central Military Hospital of Algiers, Algeria. All five strains, one
Providencia stuartii
strain, two
Escherichia coli
strains, and two
Klebsiella pneumoniae
strains, were intermediate or resistant to all β-lactams, including carbapenems. Synergy between imipenem and EDTA was observed for all five strains. The results of the PCR experiment confirmed the presence of a
bla
VIM
gene in all five strains. The
bla
VIM
genes were located as part of a class 1 integron on a 180-kb conjugative plasmid. They encoded a novel metallo-β-lactamase designated VIM-19, which differed from the parental enzyme VIM-1 by only two substitutions: Ser228Arg, previously observed in the closely related enzyme VIM-4, and Asn215Lys, not previously observed in other VIM-type carbapenemases. VIM-19 was further characterized after purification through determination of its kinetic constants. This enzyme was inhibited by EDTA and hydrolyzed penicillins, cephalosporins, and carbapenems, as observed for other VIM-type carbapenemases but with greater catalytic efficiency against penicillins than VIM-1. VIM-19 is the first carbapenemase enzyme identified from an isolate from Algeria. These results confirm the emergence of VIM-4-like enzymes in members of the family
Enterobacteriaceae
from Mediterranean countries.
Factors Associated with Virological Response to Etravirine in Nonnucleoside Reverse Transcriptase Inhibitor-Experienced HIV-1-Infected Patients
Authors: Marcelin Anne-Genevieve , Flandre Philippe , Descamps Diane , Morand-Joubert Laurence , Charpentier Charlotte , Izopet Jacques , Trabaud Mary-Anne , Saoudin Henia , Delaugerre Constance , Tamalet Catherine , Cottalorda Jacqueline , Bouvier-Alias Magali , Bettinger Dominique , Dos Santos Georges , Ruffault Annick , Alloui Chakib , Henquell Cecile , Rogez Sylvie , Barin Francis , Signori-Schmuck Anne , Vallet Sophie , Masquelier Bernard , Calvez Vincent
Published: November 2009

To identify factors associated with virological response (VR) to an etravirine (ETR)-based regimen, 243 patients previously treated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) were studied. The impact of baseline HIV-1 RNA, CD4 cell count, past NNRTIs used, 57 NNRTI resistance mutations, genotypic sensitivity score (GSS) for nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors (PIs), and the number of new drugs used with ETR for the first time on the VR to an ETR regimen were investigated. Among the 243 patients, the median baseline HIV-1 RNA level was 4.4 log10copies/ml (interquartile range [IQR], 3.7 to 4.9) and the median CD4 count was 175 cells/mm3(IQR, 69 to 312). Patients had been previously exposed to a median of 6 NRTIs, 1, NNRTI, and 5 PIs. Overall, 82% of patients achieved a VR at month 2, as defined by a decrease of at least 1.5 log10copies/ml and/or HIV-1 RNA level of <50 copies/ml. No difference in VR was observed between patients receiving or not a boosted PI in combination with ETR. Factors independently associated with a better VR to ETR were the number of drugs (among enfuvirtide, darunavir, or raltegravir) used for the first time in combination with ETR and the presence of the K103N mutation at baseline. Mutations Y181V and E138A were independently associated with poor VR, whereas no effect of the Y181C on VR was observed. In conclusion, ETR was associated with high response rates in NNRTI-experienced patients in combination with other active drugs regardless of the therapeutic class used.
A Novel Class of
meso
-Tetrakis-Porphyrin Derivatives Exhibits Potent Activities against Hepatitis C Virus Genotype 1b Replicons
In Vitro
Authors: Cheng Yao , Tsou Lun K. , Cai Jianfeng , Aya Toshihiro , Dutschman Ginger E. , Gullen Elizabeth A. , Grill Susan P. , Chen Annie Pei-Chun , Lindenbach Brett D. , Hamilton Andrew D. , Cheng Yung-chi
Published: November 2009

Recent years have seen the rapid advancement of new therapeutic agents against hepatitis C virus (HCV) in response to the need for treatment that is unmet by interferon (IFN)-based therapies. Most antiviral drugs discovered to date are small molecules that modulate viral enzyme activities. In the search for highly selective protein-binding molecules capable of disrupting the viral life cycle, we have identified a class of anionic tetraphenylporphyrins as potent and specific inhibitors of the HCV replicons. Based on the structure-activity relationship studies reported herein,
meso
-tetrakis-(3,5-dicarboxy-4,4′-biphenyl) porphyrin was found to be the most potent inhibitor of HCV genotype 1b (Con1) replicon systems but was less effective against the genotype 2a (JFH-1) replicon. This compound induced a reduction of viral RNA and protein levels when acting in the low nanomolar range. Moreover, the compound could suppress replicon rebound in drug-treated cells and exhibited additive to synergistic effects when combined with protease inhibitor BILN 2061 or with IFN-α-2a. Our results demonstrate the potential use of tetracarboxyphenylporphyrins as potent anti-HCV agents.
Baculovirus-Based Nasal Drop Vaccine Confers Complete Protection against Malaria by Natural Boosting of Vaccine-Induced Antibodies in Mice
Authors: Yoshida Shigeto , Araki Hitomi , Yokomine Takashi
Published: November 2009

Blood-stage malaria parasites ablate memory B cells generated by vaccination in mice, resulting in diminishing natural boosting of vaccine-induced antibody responses to infection. Here we show the development of a new vaccine comprising a baculovirus-basedPlasmodium yoelii19-kDa carboxyl terminus of merozoite surface protein 1 (PyMSP119) capable of circumventing the tactics of parasites in a murine model. The baculovirus-based vaccine displayed PyMSP119on the surface of the virus envelope in its native three-dimensional structure. Needle-free intranasal immunization of mice with the baculovirus-based vaccine induced strong systemic humoral immune responses with high titers of PyMSP119-specific antibodies. Most importantly, this vaccine conferred complete protection by natural boosting of vaccine-induced PyMSP119-specific antibody responses shortly after challenge. The protective mechanism is a mixed Th1/Th2-type immunity, which is associated with the Toll-like receptor 9 (TLR9)-dependent pathway. The present study offers a novel strategy for the development of malaria blood-stage vaccines capable of naturally boosting vaccine-induced antibody responses to infection.
CXCL10 Production by Human Monocytes in Response to
Leishmania braziliensis
Infection
Authors: Vargas-Inchaustegui Diego A. , Hogg Alison E. , Tulliano Gianfranco , Llanos-Cuentas Alejandro , Arevalo Jorge , Endsley Janice J. , Soong Lynn
Published: November 2009

Leishmania
(subgenus
Viannia
)
braziliensis
is the causative agent of mucocutaneous leishmaniasis (ML) in South America, and ML is characterized by excessive T- and B-cell responses to the parasite. We speculate that the unbalanced production of inflammatory mediators in response to
L
.
braziliensis
infection contributes to cell recruitment and disease severity. To test this hypothesis, we first examined the response of peripheral blood mononuclear cells (PBMCs) from healthy volunteers to
L
.
braziliensis
infection. We observed that while
L
.
braziliensis
infection induced the production of chemokine (C-X-C motif) ligand 10 (CXCL10) and interleukin-10 (IL-10) in human PBMCs and macrophages (MΦs), enhanced expression of CXCL10 and its receptor, chemokine CXC receptor (CXCR3), was predominantly detected in CD14
+
monocytes. The chemoattractant factors secreted by
L
.
braziliensis
-infected cells were highly efficient in recruiting uninfected PBMCs (predominantly CD14
+
cells) through Transwell membranes. Serum samples from American tegumentary leishmaniasis (ATL) patients (especially the ML cases) had significantly higher levels of CXCL10, CCL4, and soluble tumor necrosis factor (TNF) receptor II (sTNFRII) than did those of control subjects. Our results suggest that, following
L
.
braziliensis
infection, the production of multiple inflammatory mediators by the host may contribute to disease severity by increasing cellular recruitment.
TheSalmonella entericaSerotype Typhi Vi Capsular Antigen Is Expressed after the Bacterium Enters the Ileal Mucosa
Authors: Tran Quynh T. , Gomez Gabriel , Khare Sangeeta , Lawhon Sara D. , Raffatellu Manuela , Bäumler Andreas J. , Ajithdoss Dharani , Dhavala Soma , Adams L. Garry
Published: November 2009

Salmonella entericaserotype Typhi, the etiological agent of typhoid fever, produces the Vi capsular antigen, a virulence factor absent inSalmonella entericaserotype Typhimurium. Previous studies suggest that the capsule-encodingviaBlocus reduces inflammatory responses in intestinal tissue; however, there are currently no data regarding the in vivo expression of this locus. Here we implemented direct and indirect methods to localize and detect Vi antigen expression within polarized intestinal epithelial cells and in the bovine ileal mucosa. We report thattviB, a gene necessary for Vi production inS.Typhi, was significantly upregulated during invasion of intestinal epithelial cells in vitro. During infection of bovine ligated loops,tviBwas expressed at levels significantly higher in calf tissue than those in the inoculum. The presence of the Vi capsular antigen was detected in calf ileal tissue via fluorescence microscopy. Together, these results support the concept that expression of the Vi capsular antigen is induced whenS.Typhi transits from the intestinal lumen into the ileal mucosa.
Some aspects of the mechanics of arching in backfilled stopes
Authors: Fahey Martin , Helinski Matthew , Fourie Andy
Published: November 2009

In current underground mining using “open stoping” methods, it is common to backfill mined-out voids (“stopes”) using hydraulically placed backfill, which is commonly composed of tailings, to which cement is often added. Knowledge of the stress state within a backfilled stope is required for safe design of drawpoint barricades and for other operational reasons. This stress state depends, inter alia, on the degree of “arching” that occurs, resulting from the development of shear stress between the fill and the stope walls. This paper presents a numerical modelling study of aspects of the arching phenomenon, carried using the computer code Plaxis. The backfill is characterized using the Mohr–Coulomb soil model, and both dry backfill and saturated backfill are considered to completely cover the full spectrum of backfill types that are used in practice. It is shown that even with dry backfill, the behaviour is governed by a complex interaction between the soil parameters. The behaviour is more complex with saturated backfill, with a key parameter being the permeability of the backfill relative to the rate of filling — i.e., whether the backfilling operation can be considered to be “drained” or “undrained” or somewhere between these two extremes.
Interpretation of cone penetration tests — a unified approach
Authors: Robertson P. K.
Published: November 2009

The electric cone penetration test (CPT) has been in use for over 40 years and is growing in popularity in North America. This paper provides some recent updates on the interpretation of some key geotechnical parameters in an effort to develop a more unified approach. Extensive use is made of the normalized soil behaviour type (SBTn) chart based on normalized cone resistance (Qt) and normalized friction ratio (Fr). Updates are provided regarding the normalization process and its application to the identification of soil type. The seismic CPT has provided extensive data linking CPT net cone resistance to shear-wave velocity and soil modulus. New correlations are presented in the form of contours of key parameters on the SBTn chart. These new relationships enable a more unified interpretation of CPT results over a wide range of soils. Updates are also provided in terms of in situ state parameter, peak friction angle, and soil sensitivity. The correlations are evaluated using available laboratory and full-scale field test results. Many of the recommendations contained in this paper are focused on low to moderate risk projects where empirical interpretation tends to dominate. For projects where more advanced methods are more appropriate, the recommendations provided in this paper can be used as a screening to evaluate critical regions–zones where selective additional in situ testing and sampling maybe appropriate.
Response of a polyvinyl chloride water pipe when transverse to an underlying pipe replaced by pipe bursting
Authors: Cholewa J. A. , Brachman R. W.I. , Moore I. D.
Published: November 2009

An existing deteriorated or hydraulically undersized pipe can be replaced with a new pipe by static pipe bursting. Cavity expansion during pipe bursting induces ground movements, which may potentially damage nearby buried utilities if they are in close proximity to the pipe bursting operation. A large-scale pipe bursting experiment was performed in an 8 m long, 8 m wide, and 3 m deep test pit filled with a well-graded sand and gravel soil. A polyvinyl chloride (PVC) pipe, crossing transversely and 0.45 m above the existing pipe being replaced, was instrumented with strain gages to quantify the response of that transverse utility to the ground movements associated with pipe bursting. In this paper, the measured strain and corresponding deflection of the PVC pipe are examined and compared with measurements of surface uplift. The maximum longitudinal strain measured in the pipe was less than 0.1% and its vertical diameter decreased by only 0.5%, suggesting that ground displacements induced by pipe bursting did not jeopardize the transverse water pipe’s long-term performance, provided its joints were not damaged. A simplified design equation is introduced and shown to provide estimates of maximum longitudinal strain in the PVC pipe close to those measured during the laboratory experiment.
COMPARATIVE INVESTIGATIONS ON MAGNETICAL ENHANCED NEGATIVE- AND POSITIVE-CORONA DISCHARGES
Authors: MI JUNFENG , XU DEXUAN , TIAN XIMEI , SUN YINGHAO , ZHANG XIAOYU
Published: November 2009

The magnetically enhanced negative- and positive-corona discharges were compared in the current study. In the magnetically enhanced corona discharges, some small permanent magnets were employed to form the local magnetic fields on the corona discharge region, in which the Larmor movements of free electrons enhance ionizations of the gas molecules. The characteristics of discharge current changing in the magnetically enhanced corona discharges were firstly revealed here. The experimental results showed that the relative increases of corona discharge currents had a maximum value in both the magnetically enhanced negative- and positive-corona discharges, when a magnetic field was fixed and the inter-electrode voltages were changed. The reasons for the maximum values were analyzed in detail. In addition, comparing with the magnetically enhanced positive-corona discharge, the inter-electrode voltage for the maximum value is lower for the negative one, because the intensity of inter-electrode electric field was altered by the accumulations of positive or negative ions.
SPIN-POLARIZED DENSITY FUNCTIONAL STUDY ON HETEROFULLERENE AND METALLOFULLERENE CLUSTERS
Authors: SINGH RANBER , PRAKASH SATYA
Published: November 2009

The fullerene cage clusters C 60 and C 70 become magnetic and half metallic when doped with B and N atoms. The five-atom transition metal clusters of Mn , Fe , Co , and Ni encapsulated inside fullerene cages have higher magnetic moment, while that of Cr become nonmagnetic as compared to corresponding isolated clusters. These clusters encapsulated inside fullerene cages get distorted. The distortion in a cluster inside C 70 is larger as compared to that inside C 60, C 59 B , and C 59 N cages. These clusters also distort the hexagons and pentagons of fullerene cages. The fullerene cages expand but retain their shapes. The energy calculations show that Mn and Cr clusters encapsulated inside C 60 and C 59 N are stable.
SPLIT-EXTENSIONS OF EXCHANGE RINGS: A DIRECT PROOF
Authors: CĂLUGĂREANU GRIGORE
Published: November 2009

A direct ring-theoretic proof for "if R is a ring, e is an idempotent and eRe and (1 - e)R(1 - e) are both exchange rings then R is also an exchange ring" (left open for the last 31 years) is given.
Correlation of Plasma MMP-1 and TIMP-1 Levels and the Colonic Mucosa Expressions in Patients with Ulcerative Colitis
Authors: Wang Ying-De , Tan Xiao-Yan , Zhang Ke
Published: November 2009

Background. Both plasma and mucosal levels of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) have been shown to be independently correlated with ulcerative colitis (UC), but their relationship with each other and to disease severity remains unclear. This study aims to evaluate the relationship between colonic mucosal and plasma levels of MMP-1 and TIMP-1 with each other and with the severity of ulcerative colitis (UC).Methods. Colonic mucosal lesions and venous blood samples were collected from 30 patients with UC and 15 normal subjects. Real-time reverse transcription-PCR and immunohistochemistry were used to determine colonic mucosal MMP-1 and TIMP-1 expression; ELISA was used to measure plasma levels of MMP-1 and TIMP-1.Results. Expression of colonic mucosal and plasma MMP-1 and TIMP-1 in patients with UC was significantly higher than that of controls (P<.05), and was positively correlated with disease severity (P<.05). Plasma MMP-1 and TIMP-1 levels were well correlated with their corresponding expression in colonic mucosa (P<.05,r=0.805 and 0.908).Conclusion. Plasma MMP-1 and TIMP-1 levels reflect their colonic mucosal expression to some extent in patients with UC. Plasma MMP-1 and TIMP-1, in particular, demonstrate the potential to become biomarkers to clinically diagnose UC, predict its severity, and guide further therapy.
Dwarf Cosmology with the Stromlo Missing Satellites Survey
Authors: Jerjen Helmut
Published: November 2009

The standard Lambda Cold Dark Matter model is considered to be a triumph of theoretical astrophysics but observations of the Milky Way and its system of satellite galaxies irresistibly signal that theory is incomplete on galactic and subgalactic scales. The Stromlo Missing Satellites (SMS) Survey is a critical endeavor to investigate at what level predictions of
CDM cosmology are consistent with the observed matter distribution in the Milky Way halo. It will be the deepest, most extended search for optically elusive satellite galaxies to date, covering 20 000 square degrees of sky. The international SMS Survey collaboration will exploit 150 TB of CCD images in six filters acquired by the new SkyMapper telescope of the Australian National University over the next five years, expecting on completion photometric limits 0.5–1.0 mag fainter than the Sloan Digital
Sky Survey. The primary objective of the program is to characterise the baryonic and dark matter components of a complete sample of MW satellites in the Southern hemisphere to provide stringent observational constraints for improving our understanding of how the Milky Way formed and what physical processes governed galaxy formation and evolution in general.
Nonexpansive Matrices with Applications to Solutions of Linear Systems by Fixed Point Iterations
Authors: Lim Teck-Cheong
Published: November 2009

We characterize (i) matrices which are nonexpansive with respect to some matrix norms, and (ii) matrices whose average iterates approach zero or are bounded. Then we apply these results to iterative solutions of a system of linear equations.
Sheddase Activity of Tumor Necrosis Factor-α Converting Enzyme Is Increased and Prognostically Valuable in Head and Neck Cancer
Authors: Ge Lisheng , Baskic Dejan , Basse Per , Vujanovic Lazar , Unlu Sebnem , Yoneyama Toshie , Vujanovic Andrea , Han Jie , Bankovic Dragic , Szczepanski Miroslaw J. , Hunt Jennifer L. , Herberman Ronald B. , Gollin Susanne M. , Ferris Robert L. , Whiteside Theresa L. , Myers Eugene N. , Vujanovic Nikola L.
Published: November 2009

Tumor necrosis factor α converting enzyme (TACE) is a sheddase overexpressed in cancers that generates cancer cell growth and survival factors, and is implicated in carcinogenesis and tumor growth. This indicates that TACE could be a potentially important cancer biomarker. Unexpectedly, TACE expression in cancer tissues does not correlate with cancer stage or invasiveness. Although TACE sheddase activity is a more direct and potentially better indicator of TACE biology and might be a better cancer biomarker than TACE expression, it has not been studied in cancer tissues. In the present study, we developed a reliable specific assay for quantification of TACE sheddase activity, investigated TACE activity and TACE protein expression in head and neck cancer (HNC) tissues, and examined the correlation of the results with HNC clinical stages and likelihood to recur. We found that HNC cell lines and tissues contained remarkably higher quantities of TACE activity and TACE protein than normal keratinocytes or oral mucosa. siRNA silencing of TACE resulted in the inhibition of release of the tumorogenic factors amphiregulin and transforming growth factor α, and tumor protective factors tumor necrosis factor receptors from HNC cells. Importantly, TACE activity, but not TACE protein expression, was significantly higher in large, T3/T4, primary tumors relative to small, T1/T2, primary tumors, and especially in primary tumors likely to recur relative to those unlikely to recur. These data show that increased TACE activity in cancer is biologically and clinically relevant, and indicate that TACE activity could be a significant biomarker of cancer prognosis. (Cancer Epidemiol Biomarkers Prev 2009;18(11):2913–22)
Association between Lifestyle Factors and CpG Island Methylation in a Cancer-Free Population
Authors: Brait Mariana , Ford Jean G. , Papaiahgari Srinivas , Garza Mary A. , Lee Jin I. , Loyo Myriam , Maldonado Leonel , Begum Shahnaz , McCaffrey Lee , Howerton Mollie , Sidransky David , Emerson Mark R. , Ahmed Saifuddin , Williams Carla D. , Hoque Mohammad Obaidul
Published: November 2009

Background: Many risk factors have been associated with cancer, such as age, family history, race, smoking, high-fat diet, and poor nutrition. It is important to reveal the molecular changes related to risk factors that could facilitate early detection, prevention, and overall control of cancer.

Methods: We selected six cancer-specific methylated genes that have previously been reported in primary tumors and have also been detected in different bodily fluids of cancer patients. Here, we used quantitative fluorogenic real-time methylation-specific PCR in plasma DNA samples for the detection of methylation changes from an asymptomatic population who do not have any known cancer.

Results: The promoter methylation frequencies of the studied genes were as follows: APC (7%), CCND2 (22%), GSTP1 (2%), MGMT (9%), RARβ2 (29%), and P16 (3%). Promoter methylation of at least one of the genes analyzed was observed in ∼46% (72 of 157) of the samples by binary dichotomization. Promoter hypermethylation of at least two genes was detected in 17% (26 of 157) of the samples. RARβ2 methylation was observed in 45% of subjects who had a high-fat diet in contrast with those who had a low-fat diet (23%; P = 0.007).

Discussion: Our findings may help to elucidate early methylation changes that may lead to cancer development. These methylation changes could be due to exposure to risk factors and may be useful for cancer prevention measures such as changes in lifestyle. Longitudinal follow-up of a high-risk population is needed to understand the association of methylation of candidate genes in cancer development. (Cancer Epidemiol Biomarkers Prev 2009;18(11):2984–91)
Human Papillomavirus 16 Load and E2/E6 Ratio in HPV16-Positive Women: Biomarkers for Cervical Intraepithelial Neoplasia ≥2 in a Liquid-Based Cytology Setting?
Authors: Boulet Gaëlle A.V. , Benoy Ina H. , Depuydt Christophe E. , Horvath Caroline A.J. , Aerts Marc , Hens Niel , Vereecken Annie J. , Bogers Johannes J.
Published: November 2009

This retrospective case-control study assessed human papillomavirus 16 (HPV16) viral load and E2/E6 ratio as risk markers for cervical intraepithelial neoplasia (CIN) ≥2 lesions in HPV16-positive women in a routine liquid-based cytology setting. Triplex quantitative PCR for HPV16 E6, E2, and β-globin was done to determine the HPV16 load and the E2/E6 ratio, as a surrogate marker for integration, for women with a negative histologic endpoint (200 controls: 83 normal histology and 117 CIN1) and women with a ≥CIN2 endpoint (180 cases: 41 CIN2, 122 CIN3, and 17 invasive carcinoma). Our analysis showed a significantly higher HPV16 load in the case group, which was completely attributable to the high viral load of samples with invasive carcinoma as histologic endpoint. There was no significant difference in viral load between the other histologic groups. The E2/E6 ratio proved to be lower for the cases. However, the E2/E6 ratio indicated the presence of HPV integration in a considerable amount of control samples (44.3%), which suggests that HPV integration occurs early in the development of cancer and undermines the clinical value of viral integration. Overall, the intrinsic heterogeneous nature of the cervical cytology samples caused a substantial overlap of the HPV16 load and the E2/E6 ratio between controls and cases, which precludes the determination of cutoff values for risk prediction and hampers the clinical applicability in a cervical screening setting. (Cancer Epidemiol Biomarkers Prev 2009;18(11):2992–9)