bluuebunny/crossref_metadata_2025_split huggingface dataset:
Consistent inelastic design spectra: Strength and displacement
Authors: Vidic Tomaž , Fajfar Peter , Fischinger Matej 
Published: April 2007

AbstractA procedure for the determination of inelastic design spectra (for strength, displacement, hysteretic and input energy) for systems with a prescribed ductility factor has been developed. All the spectra are consistent (interrelated and based on the same assumptions). This is the first of two companion papers which deals with the ‘classical’ structural parameters: strength and displacement. The input data are the characteristics of the expected ground motion in terms of a smooth elastic pseudo‐acceleration spectrum. Simple, approximate expressions for the strength reduction factor R are proposed. The value of R depends on the natural period of the system, the prescribed ductility factor, the hysteretic behaviour, damping and ground motion. Fairly accurate approximations to the inelastic spectra for strength and displacement can be derived from the elastic spectrum using the proposed values for R.
Inelastic seismic response of torsionally unbalanced systems designed using elastic dynamic analysis
Authors: Wong C. M. , Tso W. K. 
Published: April 2007

AbstractThis paper evaluates the inelastic seismic response of torsionally unbalanced structural systems with strength distributed using elastic response spectrum analysis. The structural model is a single mass torsionally unbalanced system with lateral load resisting elements spanning in two principal directions. The element strength is distributed based on elastic response spectrum analysis and three different approaches to incorporate accidental torsion are considered: (a) without incorporating accidental torsion; (b) by applying static floor torques; (c) by shifting the location of the centre of mass. The seismic input is bidirectionally applied at the base of the model. It is shown that the inelastic responses depend strongly on the torsional stiffness of the system. For a torsionally stiff system, the torsional response leads to a decrease in the stiff edge displacement; however, for a torsionally flexible system, it tends to increase the stiff edge displacement. Using response spectrum analysis without including accidental torsion may lead to excessive additional ductility demand on the stiff edge element. With accidental torsion effect incorporated, the response spectrum analysis will give a strength distribution such that there will be no excessive additional ductility demands on the lateral load resisting elements.
Experimental observations on the seismic shear performance of RC beam‐to‐column connections subjected to varying axial column force
Authors: Agbabian M. S. , Higazy E. M. , Abdel‐Ghaffar A. M. , Elnashai A. S. 
Published: April 2007

AbstractThe paper presents results from the first series of an ongoing experimental study aimed at quantifying the effect of axial column load on the shear capacity of beam‐to‐column connections. This is deemed important due to the recent evidence showing that vertical earthquake ground motion, when combined with high overturning moments, may cause reduced column compression or even tension. In which case, the concrete contribution to shear resistance in the panel zone is diminished, which may lead to failure prior to the attainment of the full resisting capacity of the beam section. The results first show that the failure mode of the models was, as intended, shear failure of the panel zone. It is further observed that the axial column load has a marked effect on the shear deformation capacity, yield point, cracking pattern, ultimate capacity and ductility of the panel zone. Differences in the range of 30 per cent in capacity and 50 per cent in deformability were recorded. The preliminary results are useful in providing design guidance for structures located in areas of potential high vertical ground motion component. Also, for high‐rise structures, where there are large overturning moments, the results may be of use in ensuring a uniform safety factor (or overstrength) in various non‐dissipative parts of the structure.
Using accidental eccentricity in code‐specified static and dynamic analyses of buildings
Authors: de la Llera Juan Carlos , Chopra Anil K. 
Published: April 2007

AbstractThe differences between the increase in building response due to accidental eccentricity predicted by code‐specified static and dynamic analyses are studied for symmetric and unsymmetric single and multistorey buildings. The increase in response computed from static analysis of the building is obtained by applying the equivalent static forces at distance ea, equal to the storey accidental eccentricity, from the centre of mass at each floor. Alternatively, this increase in response is computed by dynamic analysis of the building with the centre of mass of each floor shifted through a distance ea from its nominal position. A parametric study is performed on single‐storey systems in order to evaluate the differences in response predicted by both analysis procedures. It is shown that these results are essentially the same as the ones obtained for a special class of multistorey systems. Upper and lower bounds for the differences in response computed from static and dynamic analyses are obtained for general multistorey systems. These differences in response depend primarily on the ratio of the fundamental torsional and lateral frequencies of the building. They are larger for small values of the frequency ratio and decrease to zero as the frequency ratio becomes large. Further, these discrepancies are in many cases of the same order as the code‐intended increase in response due to accidental eccentricity. This implies that the code‐specified static and dynamic analyses to account for accidental torsion should be modified to be mutually consistent.
Subgrade model for transient response analysis of multiple embedded bodies
Authors: Konagai Kazuo , Nogami Toyoaki 
Published: April 2007

AbstractDuring the dynamic response of multiple partially or fully embedded structures, the subgrade medium at the sides of the structures not only generates the soil‐structure interaction forces but also transmits the motions from one structural body to others. With Winkler's hypothesis, these forces and motions are formulated in the time‐domain in a simple form utilizing the frequency‐domains formulations. The validity of the developed formulations is examined using small‐scale‐model test results obtained for piles in a synthetic ground. A numerical example is provided to demonstrate the approach proposed and the formulations developed. The simplified time‐domain formulations are found to be numerically efficient and yet capable of predicting the behaviour reasonably well.
Earthquake collapse analysis of steel frames
Authors: Challa V. R. Murty , Hall John F. 
Published: April 2007

AbstractThe non‐linear response of planar moment‐resistant steel frames is investigated with regard to P‐Δ‐type collapses under severe earthquake ground motions. The frame model employs configuration updating, fibre‐type beam‐column members with geometric stiffness, panel zone elements at the beam‐to‐column junctions, and realistic hysteretic relations which are used for both the fibres and panel zones. Frame design follows the 1991 Uniform Building Code, and three panel zone designs are considered. It is found that P‐Δ collapse of the 20‐storey frame examined results from the formation of a collapse mechanism involving the lowest few stories. Column hinging occurs even though the code requirement that column strength exceed beam strength is satisfied. Among the different panel zone designs, the weakest one proved most resistant to developing a collapse mechanism in the frame.
Dynamic response of single piles embedded in transversely isotropic layered media
Authors: Liu Weiming , Novak Milos 
Published: April 2007

AbstractDynamic response of single piles embedded in transversely isotropic layered media is investigated using the finite element method combined with dynamic stiffness matrices of the soil derived from Green's functions for ring loads. The influence of soil anisotropy on the dynamic behaviour of piles is examined through a series of parametric studies.
Dam‐foundation rock interaction effects in frequency‐response functions of arch dams
Authors: Tan Hanchen , Chopra Anil K. 
Published: April 2007

AbstractThe linear response of a selected arch dam to harmonic upstream, vertical or cross‐stream ground motion is presented for a wide range of the important system parameters characterizing the properties of the dam, foundation rock, impounded water and reservoir boundary materials. Based on these frequency‐response functions, the dam‐foundation rock interaction effects in the dynamic response of arch dams are investigated.
Dynamic response of a pair of walls retaining a viscoelastic solid
Authors: Veletsos A. S. , Parikh V. H. , Younan A. H. 
Published: April 2007

AbstractMaking use of a previously reported, simple, approximate method of analysis, a critical evaluation is made of the dynamic pressures and forces induced by horizontal ground shaking on a pair of infinitely long, parallel walls retaining a uniform viscoelastic solid. The walls are presumed to be rigid but elastically constrained against rotation at their base. The effects of both harmonic and earthquake‐induced excitations are examined. The accuracy of the method is assessed by comparing its predictions for the special case of fixed‐based walls with those obtained by an exact method, and comprehensive numerical data are presented which elucidate the underlying response mechanisms, and the effects and relative importance of the parameters involved. The parameters examined include the characteristics of the ground motion, the ratio of the distance between walls to the height of the contained material, and the flexibility of the rotational wall constraints. In addition to valuable insights into the responses of the systems investigated, the results presented provide a convenient framework for the analysis of more complex systems as well.
Displacement‐based design of RC bridge columns in seismic regions
Authors: Kowalsky Mervyn J. , Priestley M. J. Nigel , MacRae Gregory A. 
Published: April 2007

AbstractThis paper presents a seismic design philosophy based on displacements rather than forces. By inverting the seismic design process, a rational method is established where member strength and stiffness depend on the target displacement. A comprehensive procedure for displacement‐based design of cantilever bridge columns is presented and verified by dynamic inelastic time history analysis. Parameter studies are used to examine the influence of several variables within the possible design solution space.
Time domain procedure of FE‐BE‐IBE coupling for seismic interaction of arch dams and canyons
Authors: Chuhan Zhang , Feng Jin , Pekau O. A. 
Published: April 2007

AbstractA procedure for three‐dimensional (3‐D) coupling of finite elements (FEs), boundary elements (BEs) and infinite boundary elements (IBEs) is presented for the numerical modelling of seismic interaction between arch dams and rock canyons. First, a system of coupling 3‐D boundary and infinite boundary elements is developed for simulation of infinite and irregular canyons and for determination, in the frequency domain, of impedance functions on the dam‐canyon interface. Secondly, the impedance functions for all degrees‐of‐freedom are transformed approximately into frequency independent discrete parameters by a curve fitting technique. Finally, these discrete parameters are combined with the dam structure which is discretized by finite elements, thus allowing the response of the arch dam‐canyon system to be evaluated. The proposed procedure is efficient because it permits the seismic analysis of arch dam‐canyon interaction by the substructure technique in the time domain. To demonstrate both the validity and efficiency of the present procedure, the response of an arch dam‐canyon system is obtained under unit impulse acting on the dam‐canyon interface as the free field input. Very good agreement is noted when comparing the frequency response determined from the time domain with that from the frequency domain under harmonic excitation applied on the interface of the dam‐canyon.
Volatile components of Thymus vulgaris L. from wild‐growing and cultivated plants in Jordan
Authors: Hudaib M. , Aburjai T. 
Published: April 2007

AbstractThe composition of the essential oil hydrodistilled from the aerial parts of Thymus vulgaris L. grown in Jordan has been determined by GC and GC–MS. Variations in oil composition and yield between cultivated and wild‐growing plants collected from different localities, at different altitudes, have been also evaluated. Higher oil yields were observed in plants growing wild (3.7–5.6% of dried material) than in cultivated plants (1.1–2.0%), and those collected from the Mshaqar region, in the middle of Jordan and at the highest altitude, were the richest in oil (∼5.4%). Generally, the oil was characterized by marked levels of phenolic monoterpenoids (mainly thymol and carvacrol) in the range 70.8–89.0%. High levels of the monoterpenoid hydrocarbons p‐cymene (3.4–8.2%) and γ‐terpinene (1.6–7.7%) were also observed. Other major components were 1,8‐cineole (up to 2.1%), α‐thujone (up to 1.2%), camphor (up to 1.1%) and β‐caryophyllene (0.2–2.8%). With the exception of plants growing wild in the Ramtha region, in the far north of Jordan, carvacrol was found as the principal phenol of all other oils (50.6–86.1%) and was dominant (>85%) in wild plant oils. The oil from Ramtha was characterized by the highest level of thymol (∼63.8%) as the dominant phenol and was most abundant in p‐cymene (8.2%), 1,8‐cineole (2.1%) and γ‐terpinene (7.7%). In addition to assigning carvacrol or thymol chemotypes to the plant, the high content of active monoterpenoid phenols strongly suggests a potential use of Jordanian thyme oil in cough products and antimicrobial–herbal drug combinations. Copyright © 2007 John Wiley & Sons, Ltd.
Changes in body mass, energy balance, physical function, and inflammatory state in patients with locally advanced head and neck cancer treated with concurrent chemoradiation after low‐dose induction chemotherapy
Authors: Silver Heidi J. , Dietrich Mary S. , Murphy Barbara A. 
Published: April 2007

AbstractBackground:We aimed to determine changes in body mass and body composition in relation to energy balance, inflammatory state, and physical function before and after concurrent chemoradiation (CCR).Methods:Seventeen patients with stage III and IVa head and neck cancer, aged 58.9 ± 5.4 years, who had completed a 9‐week regimen of low‐dose induction chemotherapy came to the General Clinical Research Center pre‐ and post‐CCR for measurement of body mass composition by dual‐energy X‐ray absorptiometry, resting energy expenditure (REE) by indirect calorimetry, physical performance (by Modified Baecke Questionnaire and Reuben's Physical Performance Test), and functionality (Activities and Instrumental Activities of Daily Living scores). Fasting venous samples were collected to determine C‐reactive protein and cytokines interleukin (IL)‐1β, IL‐6, IL‐8, and IL‐10. Random 24‐hour telephone diet recalls assessed energy intakes.Results:Weight loss began 1 week after CCR. Lean body mass (LBM) accounted for 71.7% ± 21% of body mass loss. No change occurred in energy intakes or calorie/nitrogen ratio. REE was significantly increased when adjusted for LBM loss (kcal/kg), p = .019. LBM loss was significantly associated with physical performance decline, r = .71, p = .004, and increased functional dependence, r = .58, p = .02. Total physical activity level declined significantly, p = .003. Cytokine levels were strongly associated with physical and functional decline.Conclusions:The aberrant changes in body composition, metabolism, and inflammatory state were associated with clinically and statistically significant impairments in physical performance and function. Future investigations and clinical practice should combine nutrition with antiinflammatory agents and exercise activities to support lean tissue anabolism and prevent physical and functional decline of patients with head and neck cancer undergoing CCR. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Role of activated nuclear factor‐κB in the pathogenesis and therapy of squamous cell carcinoma of the head and neck
Authors: Allen Clint T. , Ricker Justin L. , Chen Zhong , Van Waes Carter 
Published: April 2007

AbstractBackground:Nuclear factor‐κB (NF‐κB), a transcription factor known to modulate expression of factors involved in inflammation, immunity, proliferation, and apoptosis, is constitutively activated and plays a role in pathogenesis and therapeutic resistance in head and neck squamous cell carcinoma (HNSCC). Understanding the molecular alterations leading to aberrant NF‐κB activation in HNSCC may direct investigators to novel therapeutic targets.Methods:Results of laboratory and clinical studies are reviewed.Results:The structure, function, and activation of NF‐κB, products of NF‐κB target genes and their role in HNSCC oncogenesis, and current NF‐κB modulating interventions are described.Conclusions:Aberrant NF‐κB activation contributes to the expression of oncogenes and the malignant phenotype observed in HNSCC. NF‐κB, along with providing a link between cancer and inflammation, may serve as an appropriate therapeutic target to inhibit tumor growth and sensitize cancer cells to established cytotoxic anticancer therapies. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
The training effects of principle knowledge on fault diagnosis performance
Authors: Ham Dong‐Han , Yoon Wan Chul 
Published: April 2007

AbstractIn regard to the effectiveness of types of knowledge on fault diagnosis performance, many experimental studies showed that training with procedural knowledge (diagnostic rules) is very effective to enhance diagnosis performance. But the effects of training with principle knowledge (theoretical knowledge) have been controversial. Some studies went so far as to claim that principle knowledge is not useful for diagnosis. However, common experience suggests that understanding the principles of system dynamics is valuable in certain diagnostic situations. In this study, we conducted an experiment to investigate the value of principle knowledge in various fault situations. A context‐free digital logic circuit including 41 gates of three basic types was simulated for the subjects to diagnose. The experimental results showed that instructing principle knowledge has positive effects that are dependent on the complexity of diagnostic problems. The observations also provide insights on how fault diagnosis benefits from principle knowledge. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 263–282, 2007.
Hippocampal size positively correlates with verbal IQ in male children
Authors: Schumann Cynthia Mills , Hamstra Julia , Goodlin‐Jones Beth L. , Kwon Hower , Reiss Allan L. , Amaral David G. 
Published: April 2007

AbstractHistorically, there have been numerous proposals that the size of the brain correlates with its capacity to process information. Little is known, however, about which specific brain regions contribute to this correlation in children and adolescents. This study evaluated the relationship between intelligence and the size of various brain structures in typically developing male children 8–18 yrs of age. Magnetic resonance imaging (MRI) scans were used to measure the volume of the cerebrum, cerebral gray and white matter, cerebellum, amygdala, and hippocampus. Gray matter and hippocampal volume significantly correlated with full scale and verbal IQ. Since the hippocampus strongly correlated with verbal but not performance IQ, our findings reinforce the hypothesis that the hippocampus is involved in declarative and semantic learning, which contributes more notably to verbal IQ, than to performance IQ. Given the substantial evidence for environmentally induced changes in hippocampal structure, an unresolved issue is whether this relationship reflects genetically determined individual variation or learning induced plasticity. © 2007 Wiley‐Liss, Inc.
Most human Alu and Murine B1 repeats are unique
Authors: Umylny Boris , Presting Gernot , Efird Jimmy T. , Klimovitsky Boris I. , Ward W. Steven 
Published: April 2007

AbstractAlus and B1s are short interspersed repeat elements (SINEs) indirectly derived from the 7SL RNA gene. While most researchers recognize that there exists extensive variability between individual elements, the extent of this variability has never been systematically tested. We examined all Alu elements over 200 nucleotides and all B1 elements over 100 nucleotides in the human and mouse genomes, and analyzed the number of copies of each element at various stringencies from 22 nucleotides to full length. Over 98% of 923,277 Alus and 365,377 B1s examined were unique when queried at full length. When the criterion was reduced to half the length of the repeat, 97% of the Alus and 73% of the B1s were still found to be a single copy. All single and multi‐copy sequences have been mapped and documented. Access to the data is possible using the AluPlus website http://www.ibr.hawaii.edu. J. Cell. Biochem. 102: 110–121, 2007. © 2007 Wiley‐Liss, Inc.
Regulation of matrix Gla protein by parathyroid hormone in MC3T3‐E1 osteoblast‐like cells involves protein kinase A and extracellular signal‐regulated kinase pathways
Authors: Suttamanatwong Supaporn , Franceschi Renny T. , Carlson Ann E. , Gopalakrishnan Rajaram 
Published: April 2007

AbstractInhibition of osteoblast‐mediated mineralization is one of the major catabolic effects of parathyroid hormone (PTH) on bone. Previously, we showed that PTH induces matrix γ‐carboxyglutamic acid (Gla) protein (MGP) expression and established that this induction is critical for PTH‐mediated inhibition of osteoblast mineralization. In the present study, we focus on the mechanism through which PTH regulates MGP expression in osteoblastic MC3T3‐E1 cells. Following transient transfection of these cells with a −748 bp murine MGP promoter‐luciferase construct (pMGP‐luc), PTH (10 −7 M) induced promoter activity in a time‐dependent manner with a maximal four‐ to six fold induction seen 6 h after PTH treatment. Both H‐89 (PKA inhibitor) and U0126 (MEK inhibitor), suppressed PTH induction of MGP promoter activity as well as the MGP mRNA level. In addition, forskolin (PKA activator) stimulated MGP promoter activity and mRNA levels confirming that PKA is one of the signaling molecules required for regulation of MGP by PTH. Co‐transfection of MC3T3‐E1 cells with pMGP‐luc and MEK(SP), a plasmid encoding the constitutively active form of MEK, led to a dose‐dependent increase in MGP promoter activity. Both MGP promoter activity and MGP mRNA level were not affected by the protein kinase C (PKC) inhibitor, GF109203X. However, phorbol 12‐myristate 13‐acetate (PMA), a selective PKC activator induced MGP mRNA expression through activation of extracellular signal‐regulated kinase (ERK). Taken together, these results indicate that PTH regulates MGP via both PKA‐ and ERK‐dependent pathways. J. Cell. Biochem. 102: 496–505, 2007. © 2007 Wiley‐Liss, Inc.