bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Soil on the Dynamic Response of Liquid-Tank
Systems
Authors: Hori N. 
Published: June 2008

Abstract
A procedure is presented for the subsystem approach of a liquid-tank-soil system subjected to horizontal and vertical earthquake excitations by the Rayleigh-Ritz method. The dynamic interaction forces between the tank and soil are represented by the impedance functions obtained from the boundary element method. The tank is modeled as an elastic shell and the base of the tank is considered as a surface rigid disk resting on an elastic half-space or a layered elastic medium. A shaking table test of a liquid-elastic tank on an elastic soil model was carried out to verify experimentally the dynamic interaction. The numerical results show that the elastic response of the tank decreases due to the effect of radiation damping in the foundation. Furthermore, the experimental results show that the response of the tank decreases due to stiffness of the soil.
Simplified Models for the Dynamic Response of Tall Unanchored Liquid
Containers
Authors: Natsiavas S. 
Published: June 2008

Abstract
Two simplified models are presented for determining the hydrodynamic loads developed during the seismic response of tall unanchored liquid storage tanks. In both models the general procedure starts by first solving the fluid response problem in closed form. This eliminates all but the sloshing unknowns associated with the hydrodynamic problem. In the first model, the geometrical discretization is performed by applying the assumed mode method. In the second model, the system parameters are identified by requiring the same base loads when the real system and the model are subjected to the same base motion. During the formulation process, special attention is paid to developing a simple but sufficiently accurate analytical modeling of the mechanism associated with the separation of the base plate of the tank from its foundation, which occurs during strong ground motion. Soil flexibility and liquid sloshing effects are also modeled. The accuracy of both models is verified by comparison with experimental data. In addition, this comparison shows the applicability of these models for determining the seismic loads in tall unanchored tanks.
Numerical Prediction of Welded Joint Performance—Relative Criticality
of Weld Defect and Remote Deformation
Authors: DeGiorgi V. Gensheimer , Matic P. , Jolles M. I. 
Published: June 2008

Abstract
Structural integrity problems which deal with welded sections are common in the pressure vessel and piping industry. The current work uses continuum fracture toughness concepts to determine the structural integrity of a butt-welded plate with a lack of penetration defect in the weld material. The difference in weld and base metal properties are explicitly included in the computational simulation. The analysis technique presented does not require the analyst to assume a failure location. The critical strain energy density associated with fracture of a material at the continuum scale is used as the failure criterion.
Basis and Development of Toughness Requirements for Class 2, Class 3,
Containment and Component Support Materials in Section III of the ASME
Code
Authors: Yukawa S. , Doty W. D. , Landerman E. I. 
Published: June 2008

Abstract
In 1972, Section III of the ASME Boiler and Pressure Vessel Code adopted new fracture toughness requirements for Class 1 components based on fracture mechanics concepts. In the ensuing several years, new toughness requirements were developed and adopted for the other Section III classes of components covered by Subsections NC, ND, NE, and NF. This paper describes the chronology of these developments and the bases of the rules and criteria. The formulation of specific rules is discussed and examples of data used to support the criteria are described. The rules and requirements as initially adopted, and subsequent revisions and modifications are discussed to show their evolution into the current version.
Remaining Life of High-Energy Piping Systems Using Equivalent
Stress
Authors: Cohn M. J. 
Published: June 2008

Abstract
Fossil power plant high-energy piping systems operated at high temperatures are subject to creep damage, which is a time-dependent phenomenon. Traditional guidelines, such as the American Society of Mechanical Engineers (ASME) B31.1 Power Piping Code, were developed for plants having design lives in the 25–30 yr regime. Since many of these systems are being operated beyond 200,000 hr, it is important to reconsider the methodology of creep damage analysis to assure reliable long-term operation. Seven high-energy piping systems were evaluated in this study. The analysis of a minimum piping system life due to creep considered two approaches. The first approach used the traditional ASME B31.1 flexibility analysis guidelines. The second approach considered more detailed multiaxial stress state types of evaluations. The various equivalent stress methods used all six load components from the flexibility analysis. In nearly every case, the equivalent stress methods predicted significantly higher stresses. Consequently, the equivalent stress methodology results in 14 to 97 percent lower time to rupture values as compared to the values predicted using ASME B31.1 stresses.
Modeling of Distortion in Girth-Welded Thin Pipes
Authors: Song H. , Moshaiov A. 
Published: June 2008

Abstract
The axisymmetric distortion in girth-welded pipes is studied in this paper. A model is developed based on the fact that only a small part of the pipe near the welding arc undergoes high temperature changes, and thus behaves thermo-elastic-plastically, while the rest of the structure is elastic in nature and may, at most, have some thermo-elastic effects. The model is shown to match Finite Element Method in predicting the overall approximated axisymmetric shrinkage in girth-welded pipes. A qualitative agreement with published analytical and experimental results is achieved as well.
An Experimental Study on the Influence of Structural Damping on
Internal Fluid Pressure During a Transient Flow
Authors: Budny D. D. , Hatfield F. J. , Wiggert D. C. 
Published: June 2008

Abstract
The traditional approach to designing a piping system subject to internal dynamic pressure is to restrain the piping as much as possible, and the approximation made in the analysis is to assume no contribution of structural energy dissipation. To determine the validity of this concept and approximation, an experimental study of a piping system was performed to measure the influence of structural damping. A pipe system was designed with a loop that could be turned so that its natural frequency would match that of the contained liquid. It was discovered that a properly sized damper on the piping loop greatly accelerates the decay of the fluid pressure transient. The damper absorbs some energy from the piping, reducing the resulting rebound fluid pressure. When the loop is subjected to forced steady-state vibration, there is a fluid pressure response. The amplitude of that pressure can be reduced by installing an external damper: the stiffer the damper the more effective it is in reducing dynamic pressure.
Dynamic Response of Buried Pipelines—An Elasticity
Solution
Authors: Mishra B. K. , Upadhyay P. C. 
Published: June 2008

Abstract
This paper presents a theory of elasticity solution of the axisymmetric steady-state dynamic response of a buried pipeline excited by a plane longitudinal wave (P-wave) traveling in the surrounding soil. Both the pipeline and the ground have been assumed to be linearly elastic, homogeneous and isotropic. Linear elasticity equations of motion have been solved simultaneously for the pipeline and the surrounding soil. A perfect bond between the pipeline and the ground has been assumed. The midplane deformations of the pipeline have been plotted against the nondimensional wave number of the incident wave, for different soil condition and angle of incidence of the wave. The results of the present work have been compared with those found by using a shell theory which includes the effect of shear deformation and rotary inertia. It has been found that excellent agreement exists between the results obtained by the two approaches. The present work concludes that the use of shell model, including effects of shear deformation and rotary inertia, is justified for the analysis of dynamic response of buried pipelines excited by seismic waves traveling in the ground.
Elastic-Plastic Analysis of a Spherical Shell Loaded Radially Through
a Flexible Cylindrical Nozzle
Authors: Leung C.-P. , Brooks G. N. 
Published: June 2008

Abstract
This study investigates the elastic-plastic behavior of a shallow spherical shell loaded radially through a flexible cylindrical nozzle. Both the sphere and the cylinder can yield and exhibit plastic deformation. The Tresca yield condition is employed to derive elastic-plastic moment-curvature relationship in a simple form which is implemented in an efficient solution scheme. Three geometric parameters represent the relative dimensions of the structure. Numerical results are obtained for a range of values of these parameters. Various situations involving the failure of the sphere and/or the cylinder are studied. The ultimate or failure loads of the structure are plotted as functions of the geometric parameters.
Thermal Stresses in a Partially Filled Horizontal
Vessel
Authors: Russo E. P. , St. Cyr W. W. , Herrington P. D. 
Published: June 2008

Abstract
Stresses produced by a thermal gradient in the wall of a partially filled horizontal cylindrical vessel are presented. Three different thermal gradients are considered: 1) a discontinuous temperature change; 2) a hyperbolic temperature change; and 3) a linear temperature change at the liquid level. Thermal shock effects are also presented.
Biological Activities of Anti-Merozoite Surface Protein-1 Antibodies Induced by Adjuvant-Assisted Immunizations in Mice with Different Immune Gene Knockouts
Authors: Hui George , Choe Dan , Hashimoto Caryn 
Published: June 2008

ABSTRACTImmunizations withPlasmodium falciparumMSP1-42 or MSP1-19 induce antibodies that inhibit parasites in vitro, which correlates with in vivo protective immunity by vaccination. We previously showed that several adjuvant formulations can induce anti-MSP1-19 antibodies in interleukin-6, intercellular adhesion molecule 1, CD80, and CD86 knockout (KO) mice and at levels similar to those obtained in the healthy uninfected hosts. Here, we determine whether these immune gene KOs or the immunopotentiating activities of the adjuvants have a more important influence on the induction of parasite-inhibitory anti-MSP1-19 antibodies. Results showed that the biological activities of the anti-MSP1-19 antibodies induced by these adjuvants were not affected by the immune gene KOs. All adjuvant formulations that induced significant inhibitory antibody responses (i.e., >50% inhibition of parasite growth) contained monophosphoryl lipid A (MPL) in emulsion carriers, whereas MPL or emulsion carriers alone were ineffective. The ability to retain vaccine efficacy by the MSP1-19 and adjuvant formulations in the altered immunological background is a valuable and significant attribute in light of many instances of skewed immune status in the targeted vaccine populations.
Evidence of Multiple
Treponema
Phylotypes Involved in Bovine Digital Dermatitis as Shown by 16S rRNA Gene Analysis and Fluorescence In Situ Hybridization
Authors: Klitgaard Kirstine , Boye Mette , Capion Nynne , Jensen Tim K. 
Published: June 2008

ABSTRACT

The etiopathogenesis of the skin disease digital dermatitis (DD), an important cause of lameness in cattle, remains uncertain. Microscopically, the disease appears to be polymicrobial, with spirochetes as the predominant bacteria. The objective of this study was to identify the main part of the bacteria involved in DD lesions of cattle by using culture-independent molecular methods. Ten different phylotypes of
Treponema
were identified either by 16S rRNA gene sequencing of bacteria from DD lesions or by fluorescence in situ hybridization (FISH) analysis using phylotype-specific 16S rRNA-directed oligonucleotide probes. Two phylotypes, phylotype 1 (PT1) and PT2, were not closely related to any characterized treponemal species. PT7 was 99.3% identical to
Treponema denticola
, while PT9 resembled
T. vincentii
by 96%. The remaining phylotypes, PT3, PT4, PT5, PT6, and PT8, and
Treponema brennaborense
had previously been isolated from DD lesions. Forty DD biopsy specimens were examined for
Treponema
by FISH. With one exception, all of the biopsy specimens revealed epidermotropic, intermingled infection with three or more different phylotypes (mean, 4.7). The most prevalent species were PT1 (95%), PT6 (93%), and PT3 (85%). While colonization by PT3 was confined to the surface of the epidermis, both PT1 and PT6 invaded deep into the stratum spinosum and were seen in ulcerated dermal papillae. In two cases, all 10 phylotypes were demonstrated. Furthermore, FISH with a
Treponema
group-specific probe showed that
Treponema
accounted for more than 90% of the total bacterial population in the biopsy specimens. These data strongly suggest that a group of apparently symbiotic
Treponema
species are involved as primary bacterial pathogens in DD.
Higher Homologous and Lower Cross-Reactive Gag-Specific T-Cell Responses in Human Immunodeficiency Virus Type 2 (HIV-2) Than in HIV-1 Infection
Authors: Jennes Wim , Camara Makhtar , Dièye Tandakha , Mboup Souleymane , Kestens Luc 
Published: June 2008

ABSTRACTHuman immunodeficiency virus type 2 (HIV-2) infection results in slower CD4+T-cell decline, lower plasma viral load levels, and hence slower progression of the disease than does HIV-1 infection. Although the reasons for this are not clear, it is possible that HIV-2 replication is more effectively controlled by host responses. We used aligned pools of overlapping HIV-1 and HIV-2 Gag peptides in an enhanced gamma interferon enzyme-linked immunospot assay to compare the levels of homologous and cross-reactive Gag-specific T-cell responses between HIV-1- and HIV-2-infected patients. HIV-2-infected patients showed broader and stronger homologous Gag-specific T-cell responses than HIV-1-infected patients. In contrast, the cross-reactive T-cell responses in HIV-2-infected patients were both narrower and weaker than those in HIV-1-infected patients, in line with overall weaker correlations between homologous and heterologous T-cell responses among HIV-2-infected patients than among HIV-1-infected patients. Cross-reactive responses in HIV-2-infected patients tended to correlate directly with HIV-1/HIV-2 Gag sequence similarities; this was not found in HIV-1-infected patients. The CD4+T-cell counts of HIV-2-infected patients correlated directly with homologous responses and inversely with cross-reactive responses; this was not found in HIV-1-infected patients. Our data support a model whereby high-level HIV-2-specific T-cell responses control the replication of HIV-2, thus limiting viral diversification and priming of HIV-1 cross-reactive T-cell responses over time. However, we cannot exclude the possibility that HIV-2 replication is controlled by other host factors and that HIV-2-specific T-cell responses are better maintained in the context of slow viral divergence and a less damaged immune system. Understanding the nature of immune control of HIV-2 infection could be crucial for HIV vaccine design.
The Epstein-Barr Virus LF2 Protein Inhibits Viral Replication
Authors: Calderwood Michael A. , Holthaus Amy M. , Johannsen Eric 
Published: June 2008

ABSTRACT
The switch from Epstein-Barr virus (EBV) latent infection to lytic replication is governed by two transcriptional regulators, Zta and Rta. We previously reported that the EBV protein encoded by the LF2 gene binds to Rta and can inhibit Rta activity in reporter gene assays. We now report that LF2 associates with Rta in the context of EBV-infected cells induced for lytic replication. LF2 inhibition of Rta occurs in both epithelial and B cells, and this downregulation is promoter specific: LF2 decreases Rta activation of the BALF2, BMLF1, and BMRF1 promoters by 60 to 90% but does not significantly decrease Rta activation of its own promoter (Rp). LF2 decreases Rta activation by at least two mechanisms: decreased DNA binding and interference with transcriptional activation by the Rta acidic activation domain. Coexpression of LF2 also specifically induces modification of Rta by the small ubiquitin-like modifiers SUMO2 and SUMO3. We further demonstrate that LF2 overexpression blocks lytic activation in EBV-infected cells induced with Rta or Zta. Our results demonstrate that LF2, a gene deleted from the EBV reference strain B95-8, encodes a potent inhibitor of EBV replication, and they suggest that future studies of EBV replication need to account for the potential effects of LF2 on Rta activity.
Association of Hepatitis C Virus Replication Complexes with Microtubules and Actin Filaments Is Dependent on the Interaction of NS3 and NS5A
Authors: Lai Chao-Kuen , Jeng King-Song , Machida Keigo , Lai Michael M. C. 
Published: June 2008

ABSTRACT
The hepatitis C virus (HCV) RNA replication complex (RC), which is composed of viral nonstructural (NS) proteins and host cellular proteins, replicates the viral RNA genome in association with intracellular membranes. Two viral NS proteins, NS3 and NS5A, are essential elements of the RC. Here, by using immunoprecipitation and fluorescence resonance energy transfer assays, we demonstrated that NS3 and NS5A interact with tubulin and actin. Furthermore, immunofluorescence microscopy and electron microscopy revealed that HCV RCs were aligned along microtubules and actin filaments in both HCV replicon cells and HCV-infected cells. In addition, the movement of RCs was inhibited when microtubules or actin filaments were depolymerized by colchicine and cytochalasin B, respectively. Based on our observations, we propose that microtubules and actin filaments provide the tracks for the movement of HCV RCs to other regions in the cell, and the molecular interactions between RCs and microtubules, or RCs and actin filaments, are mediated by NS3 and NS5A.
Structural Analysis Reveals an Amyloid Form of the Human Papillomavirus Type 16 E1
∧
E4 Protein and Provides a Molecular Basis for Its Accumulation
Authors: McIntosh Pauline B. , Martin Stephen R. , Jackson Deborah J. , Khan Jameela , Isaacson Erin R. , Calder Lesley , Raj Kenneth , Griffin Heather M. , Wang Qian , Laskey Peter , Eccleston John F. , Doorbar John 
Published: June 2008

ABSTRACT

The abundant human papillomavirus (HPV) type 16 E4 protein exists as two distinct structural forms in differentiating epithelial cells. Monomeric full-length 16E1
∧
E4 contains a limited tertiary fold constrained by the N and C termini. N-terminal deletions facilitate the assembly of E1
∧
E4 into amyloid-like fibrils, which bind to thioflavin T. The C-terminal region is highly amyloidogenic, and its deletion abolishes amyloid staining and prevents E1
∧
E4 accumulation. Amyloid-imaging probes can detect 16E1
∧
E4 in biopsy material, as well as 18E1
∧
E4 and 33E1
∧
E4 in monolayer cells, indicating structural conservation. Our results suggest a role for fibril formation in facilitating the accumulation of E1
∧
E4 during HPV infection.
Nonstructural Proteins 1 and 2 of Respiratory Syncytial Virus Suppress Maturation of Human Dendritic Cells
Authors: Munir Shirin , Le Nouen Cyril , Luongo Cindy , Buchholz Ursula J. , Collins Peter L. , Bukreyev Alexander 
Published: June 2008

ABSTRACTHuman respiratory syncytial virus (RSV) is the most important agent of serious pediatric respiratory tract disease worldwide. One of the main characteristics of RSV is that it readily reinfects and causes disease throughout life without the need for significant antigenic change. The virus encodes nonstructural protein 1 (NS1) and NS2, which are known to suppress type I interferon (IFN) production and signaling. In the present study, we monitored the maturation of human monocyte-derived myeloid dendritic cells (DC) following inoculation with recombinant RSVs bearing deletions of the NS1 and/or NS2 proteins and expressing enhanced green fluorescent protein. Deletion of the NS1 protein resulted in increased expression of cell surface markers of DC maturation and an increase in the expression of multiple cytokines and chemokines. This effect was enhanced somewhat by further deletion of the NS2 protein, although deletion of NS2 alone did not have a significant effect. The upregulation was largely inhibited by pretreatment with a blocking antibody against the type I IFN receptor, suggesting that suppression of DC maturation by NS1/2 is, at least in part, a result of IFN antagonism mediated by these proteins. Therefore, this study identified another effect of the NS1 and NS2 proteins. The observed suppression of DC maturation may result in decreased antigen presentation and T-lymphocyte activation, leading to incomplete and/or weak immune responses that might contribute to RSV reinfection.
Generalized Mann Iterations for Approximating Fixed Points of a Family of Hemicontractions
Authors: Hu Liang-Gen , Xiao Ti-Jun , Liang Jin 
Published: June 2008

AbstractThis paper concerns common fixed points for a finite family of hemicontractions or a finite family of strict pseudocontractions on uniformly convex Banach spaces. By introducing a new iteration process with error term, we obtain sufficient and necessary conditions, as well as sufficient conditions, for the existence of a fixed point. As one will see, we derive these strong convergence theorems in uniformly convex Banach spaces and without any requirement of the compactness on the domain of the mapping. The results given in this paper extend some previous theorems.
Fasudil-induced hypoxia-inducible factor-1α degradation disrupts a hypoxia-driven vascular endothelial growth factor autocrine mechanism in endothelial cells
Authors: Takata Keiko , Morishige Ken-ichirou , Takahashi Toshifumi , Hashimoto Kae , Tsutsumi Seiji , Yin Limei , Ohta Tsuyoshi , Kawagoe Jun , Takahashi Kazuhiro , Kurachi Hirohisa 
Published: June 2008

Abstract
Hypoxic response of endothelial cells (EC) is an important component of tumor angiogenesis. Especially, hypoxia-inducible factor-1 (HIF-1)–dependent EC-specific mechanism is an essential component of tumor angiogenesis. Recently, the Rho/Rho-associated kinase (ROCK) signaling has been shown to play a key role in HIF-1α induction in renal cell carcinoma and trophoblast. The present study was designed to investigate whether low oxygen conditions might modulate HIF-1α expression through the Rho/ROCK signaling in human umbilical vascular ECs (HUVEC). Pull-down assay showed that hypoxia stimulated RhoA activity. Under hypoxic conditions, HUVECs transfected with small interfering RNA of RhoA and ROCK2 exhibited decreased levels of HIF-1α protein compared with nontargeted small interfering RNA transfectants, whereas HIF-1α mRNA levels were not altered. One of ROCK inhibitors, fasudil, inhibited hypoxia-induced HIF-1α expression without altering HIF-1α mRNA expression. Furthermore, proteasome inhibitor prevented the effect of fasudil on HIF-1α expression, and polyubiquitination was enhanced by fasudil. These results suggested that hypoxia-induced HIF-1α expression is through preventing HIF-1α degradation by activating the Rho/ROCK signaling in ECs. Furthermore, hypoxia induced both vascular endothelial growth factor (VEGF) and VEGF receptor-2 expression through the Rho/ROCK/HIF-1α signaling in HUVECs. Thus, augmented VEGF/VEGF receptor-2 autocrine mechanism stimulated HUVEC migration under hypoxic conditions. In summary, the Rho/ROCK/HIF-1α signaling is an essential mechanism for hypoxia-driven, VEGF-mediated autocrine loop in ECs. Therefore, fasudil might have the antimigratory effect against ECs in tumor angiogenesis. [Mol Cancer Ther 2008;7(6):1551–61]