bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of methamphetamine exposure during prenatal and preweaning periods lasts for generations in rats
Authors: Šlamberová Romana , Pometlová Marie , Rokyta Richard 
Published: March 2007

AbstractOur previous studies demonstrated that methamphetamine (MA) administration during gestation and/or lactation affects maternal behavior in rats and that birth weight and sensory‐motor coordination of their pups are also influenced. The present study tested the hypothesis that the effect of MA induces long‐term changes affecting second generation of rats that were not exposed to the drug. Adult females exposed during prenatal and preweaning periods to 5 mg/kg MA daily, were examined for regularity of estrous cycle and mated with stimulus, unexposed males. Dams (nontreated absolute control, saline‐ and MA‐exposed) were observed with their pups in two tests of maternal behavior (observational and retrieval tests). Their pups were further tested throughout the preweaning period to examine their development. Our data demonstrate that MA‐exposed mothers displayed more nursing, were more often in the nest and in contact with their pups, and were faster in retrieving their pups than saline‐exposed and/or control mothers. There were no differences in litter characteristics, birth weight and weight gain of pups between groups. Interestingly, pups from mothers exposed to MA during prenatal and preweaning period had impaired sensory‐motor coordination. They achieved righting reflex in mid‐air later than both control groups. Additionally, they had more falls in rotarod and bar‐holding tests than pups from both control and saline‐exposed mothers. In homing performance, pups from MA‐ and saline‐exposed dams learned slower to return to the home box than pups from control dams. Thus, the present study demonstrates that MA abused by mothers may affect two generations of their offspring. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 312–322, 2007.
Effects of process variables for biodiesel production by transesterification
Authors: Akgün Nalan , İşcan Emine 
Published: March 2007

AbstractIn this study, biodiesel production from various vegetable oils by transesterification was studied, to determine the optimum conditions. Experiments were carried out by using different kinds of catalysts (sodium hydroxide, potassium hydroxide, barium hydroxide, pyrolitic coke and wood ash) and feedstocks (corn oil, sunflower oil, soybean oil, olive pomace oil and cottonseed oil) at 65 °C and an agitation speed of 1000 rpm. The neutralization step with controlled pH was performed by treatment with phosphoric acid. An experimental design was used to evaluate the effects of the parameters such as types of vegetable oils, kinds of catalysts, reaction time, alcohol/oil volumetric ratio and amount of catalyst, on the methyl ester conversion. Using response surface methodology, a quadratic polynomial equation was obtained by multiple regression analysis. It was found that catalyst concentration was the most effective parameter. Sodium hydroxide and potassium hydroxide exhibited a superior catalytic behavior, whereas pyrolitic coke and wood ash had to be used in excess amount or for prolonged reaction times. Moreover, the properties such as viscosity, density, calorific value, acid value, and refractive index of the biodiesel were measured. The tri‐, di‐, monoacylglycerols and glycerol residuals in the methyl esters produced were also quantified by GC analysis.
Analysis of phospholipids by NACE with on‐line ESI‐MS
Authors: Gao Fei , Zhang Zhengxiang , Fu Xiaofang , Li Wei , Wang Tao , Liu Huwei 
Published: March 2007

AbstractA hyphenated method of nonaqueous capillary electrophoresis coupled to electrospray ionization mass spectrometry (NACE‐ESI‐MS) is described for the simultaneous analysis of phospholipids. The best results were obtained with a mixed solution of methanol/ACN (40:60 v/v) containing 20 mM ammonium acetate and 0.5% acetic acid, under the applied voltage of 30 kV and capillary temperature of 25°C. ESI‐MS measurements were performed in the negative mode with methanol/ACN (40:60 v/v) containing 50 mM ammonium acetate as sheath liquid at a flow rate of 2 μL/min. Different phospholipid classes have been successfully separated within 16 min, and the molecular species of every single class have been identified by using MS2 or MS3, which generates characteristic fragments through CID. The developed method has been applied to analyze the phospholipids extracted from rat peritoneal surface and the molecular species of phospholipid classes are presented.
A generalized continuum method for dynamic analysis of asymmetric tall buildings
Authors: Danay A. , Gluck J. , Gellert M. 
Published: March 2007

AbstractThe paper presents a continuum method for dynamic analysis of asymmetric tall buildings with uniform cross‐section in which the horizontal stiffness is provided by shear walls and columns of arbitrary shape and layout, coupled by horizontal beams.The equations of motions are formulated in variational terms, including axial strain energy. Numerical solutions, obtained by using finite time differences and infinite polynomials, are presented for the response of a twenty‐storey building with six shear walls to an impact load and earthquake accelerations.It is shown that omission of the axial deformations results in a substantially distorted pattern of behaviour, some of its effects being:
Overestimation of the bending stiffness of the coupled shear walls, with corresponding changes in their stiffness ratios.
Underestimation of the periods of the principal modes, with a corresponding change in the dynamic response.
Distortion of the magnitude, form, time of onset and coupling of the maximum displacements.
Pronounced change in the shear force and moment diagrams for the shear walls, the beams and the building as a whole.
Horizontal ground motion in los angeles during the san fernando earthquake
Authors: Crouse C. B. 
Published: March 2007

AbstractAccelerograms, Fourier amplitude spectra and response spectra from ground motion recorded in the San Fernando earthquake at selected sites in Los Angeles were examined and compared. Although differences exist in the data from the bases of a group of six tall buildings close together near the intersection of Wilshire Boulevard and Normandie Avenue, the differences are not significant from the standpoint of design. A single design spectrum is most appropriate for this area, even though there exists a variety of foundation conditions, building properties and basement configurations for the six sites.The degree to which soil‐structure interaction and the local geology affected the response could not be precisely determined from the basement accelerograms, although the data from the six Wilshire‐Normandie sites offered some evidence that soil‐structure interaction and local site conditions did not contribute significantly to the character of the recorded motions. There was some correlation between the degree of similarity in the response at two sites and their distance apart. Thus, it is possible that some differences in the response of the closely spaced buildings could result from different superposition of the seismic waves.The shapes of response spectra from all of the sites studied, including the spectra from seven buildings 2–3 miles distant from the buildings near the intersection of Wilshire Boulevard and Normandie Avenue, indicate that the character of the ground motion was probably more dependent on the source mechanism and the travel paths of the earthquake waves, rather than on more local effects.
Observations and estimation of long‐period strong ground motion in the los angeles basin
Authors: Hanks Thomas C. 
Published: March 2007

AbstractWhile the accurate estimation of ground‐motion amplitudes across the entire frequency band of engineering interest is not possible at the present time, the excitation and propagation of long‐period strong‐ground motion can be understood with existing seismological methodology. In the Los Angeles Basin, the long‐period strong ground motion excited by the San Fernando earthquake is dominated by the presence of surface waves, whose gross amplitude and frequency content are easily attributable to physical properties of the earthquake source and source‐station propagation paths. Observed measures of the long‐period strong ground motion of the Kern County earthquake relative to the San Fernando earthquake at two sites in the Los Angeles Basin which recorded both shocks can be predicted with considerable accuracy by a simple earthquake source model. This source model is extrapolated to represent the maximum credible earthquake likely to affect the Los Angeles area, taken to be a repeat of the Fort Tejon (1857) earthquake along the San Andreas fault. The measures of long‐period strong ground motion in the Los Angeles Basin estimated for it agree well with the comparable measures of Earthquake A‐2, intended to represent the same situation. For the purpose of aseismic design of long‐period structures, Earthquake A‐2 is a reasonable, if not all inclusive, estimate of the long‐period strong ground motion in the Los Angeles Basin generated by a magnitude 8+ earthquake along the San Andreas fault north and east of Los Angeles.
Response of beams to propagating boundary excitation
Authors: Masri S. F. 
Published: March 2007

AbstractAn exact solution is presented for the transient response of viscously damped Bernoulli‐Euler beams with arbitrary boundary conditions that are subjected to directly applied dynamic loads in addition to arbitrary support motion. It is shown that, for certain system characteristics, the wave‐like progression of the disturbance may have a significant influence on the structural response of such beams.
The dynamic foundation interaction of multistorey frames
Authors: Dumanoǧlu A. A. , Severn R. T. 
Published: March 2007

AbstractThis paper discusses the extent to which foundation properties influence the response of some framed structures to earthquakes.Three stages can be isolated, the first of which checks the validity of a theoretical method by means of model studies. Five models were made, a five‐storey plane frame rigidly fixed at its feet, two models of the same frame but now in association with a linearly elastic isotropic foundation, Adiprene L‐100 and L‐167, which had E‐values of 4.4 and 39.7 N/mm2, respectively. A five‐storey, asymmetric space frame was also made, with fixed feet and with a foundation of modulus 4.4 N/mm2. In this first stage, resonance tests were made, using the MAMA,2 to obtain frequencies, mode shapes and damping values. Corresponding frequencies and mode shapes were calculated using a finite element idealization.The second stage uses a proven computer program for a parametric study to obtain a large number of results, which give a good indication of the effect of different foundation conditions on this type of structure. Some calculations are also made in which the foundation is represented by equivalent springs8 instead of finite elements.In the third stage dynamic response was considered. A shaking table was built on which the models were subjected to a number of actual earthquake records, which had been suitably scaled and recorded on magnetic tape. The structural response was measured, and compared with calculated values obtained by step‐by‐step methods and, alternatively, the modal addition approach. For the asymmetric space‐frame, particular attention was paid to the torsional effect.
Ground vibrations due to seismic detonation of a buried source
Authors: Awojobi A. O. , Sobayo O. A. 
Published: March 2007

AbstractThe problem of vibrations at the free surface of an elastic half‐space due to detonation of a buried source is studied here from the viewpoint of the geophysical seismic technique employed in oil exploration. The fundamental assumption of the theory, therefore, is that the pressure at the source is impulsive and a Dirac delta function of time. The depth of the source below the surface of the medium is considered in the present theory as an additional parameter which has hitherto made the buried source problem formidable and, therefore, has limited almost all previous works to the relatively easy problem of surface blasting.An exact formulation is presented by dividing the half‐space into a stratum above the level of the buried source and a half‐space below it. For boundary conditions at the interface, it is assumed that the vertical displacement and shear stress at the level of the source are continuous while the direct stress is discontinuous. A numerical evaluation of the contour integration in the analysis is presented for the components of vibrations at any point of the free surface for a Poissonian medium. Finally, the analysis provides a theoretical justification for the interesting results obtained from field experiments recorded in an earlier work.
Shear wave velocities from down‐hole measurements
Authors: Beeston H. E. , McEvilly T. V. 
Published: March 2007

AbstractShear wave velocities of soils, which provide shear moduli for earthquake response calculations, can be measured clearly and accurately using the down‐hole method. Such a method has been used at a number of sites in California with good results to depths of 200 ft. Seismic waves from hammer blows, delivered to the ends of a heavy plank loaded by the front wheels of a vehicle, are received by a three‐component geophone in a carefully prepared vertical hole and recorded at 1 mm/ms with a six‐channel seismograph. A series of records are obtained at various measured depths in the hole, allowing calculation of interval velocities. Shear waves are easily identified by a clear 180 degrees phase difference between waves generated by blows on the opposite ends of the plank. Compressional waves are routinely logged by a vertical hammer blow at each recording depth. Shear velocities are reproducible to about 5 per cent in surveys of neighbouring holes. The reading uncertainty of ± 1 msec for the S arrival gives a resolution sufficient to detect a buried layer 5–10 ft thick with a velocity contrast of only 20 per cent.
Dynamic response of non‐linear building‐foundation systems
Authors: Bielak Jacobo 
Published: March 2007

AbstractAn analysis is made of the steady‐state response of a bilinear hysteretic structure supported on the surface of a viscoelastic half‐space. The method of equivalent linearization is used to solve the equations of motion, and simplified approximate formulas are obtained for the fundamental resonant frequency of the system and for an effective critical damping ratio. Numerical results indicate that for non‐linear hysteretic structures compliance of the soil foundation may lead to larger displacements than would occur if the base were rigid. This behaviour differs from that generally observed for linear systems, for which the effect of soil‐structure interaction is to reduce the rigid‐base response.
A substructure method for earthquake analysis of structures including structure‐soil interaction
Authors: Gutierrez Jorge A. , Chopra Anil K. 
Published: March 2007

AbstractA general substructure method for analysis of response of structures to earthquake ground motion, including the effects of structure‐soil interaction, is presented. The method is applicable to complex structures idealized as finite element systems and the soil region treated as either a continuum, for example as a viscoelastic halfspace, or idealized as a finite element system. The halfspace idealization permits reliable analysis for sites where essentially similar soils extend to large depths and there is no rigid boundary such as soil‐rock interface. For sites where layers of soft soil are underlain by rock at shallow depth, finite element idealization of the soil region is appropriate; in this case, the direct and substructure methods would lead to equivalent results but the latter provides the better alternative. Treating the free field motion directly as the earthquake input in the substructure method eliminates the deconvolution calculations and the related assumption—regarding type and direction of earthquake waves—required in the direct method.Spatial variations in the input motion along the structure‐soil interface of embedded structures or along the base of long surface supported structures are included in the formulation.The substructure method is computationally efficient because the two substructures—the structure and the soil region—are analysed separately; and, more important, it permits taking advantage of the important feature that response to earthquake ground motion is essentially contained in the lower few natural modes of vibration of the structure on fixed base.
Collocation, dissipation and [overshoot] for time integration schemes in structural dynamics
Authors: Hilber Hans M. , Hughes Thomas J. R. 
Published: March 2007

AbstractThe concept of collocation, originally used by Wilson in the development of dissipative algorithms for structural dynamics, is systematically generalized and analysed. Optimal schemes within this class are developed and compared with a recently proposed family of dissipative algorithms, called a methods. The α methods are found to be superior on the basis of standard measures of dissipation and dispersion.It is pointed out that the tendency to overshoot is an important and independent factor which should be considered in an evaluation of an implicit scheme. The basis for studying overshoot is discussed and the optimal collocation and α methods are compared. It is found that pathological overshooting is an inherent property of collocation schemes, whereas the overshooting characteristics of the α methods are good.
Dynamic response of skew bridge decks
Authors: Srinivasan R. S. , Munaswamy K. 
Published: March 2007

AbstractIn this paper the dynamic response of a skew bridge deck has been investigated, treating it as an orthotropic plate and using the finite strip method. Employing the normal mode method, the response of the deck due to a moving force has been calculated. Williams' method has been used to accelerate the convergence of the solution. Numerical work has been done for different skew angles and speed ranges. In this study, the history curves and the maximum amplification spectra for deflection and bending moment are presented.
A six‐month double‐blind, randomized, placebo‐controlled study of a transdermal patch in Alzheimer's disease–– rivastigmine patch versus capsule
Authors: Winblad Bengt , Cummings Jeffrey , Andreasen Niels , Grossberg George , Onofrj Marco , Sadowsky Carl , Zechner Stefanie , Nagel Jennifer , Lane Roger 
Published: March 2007

AbstractObjectivesTo compare the efficacy, safety and tolerability of a novel rivastigmine transdermal patch with conventional rivastigmine capsules and placebo in patients with Alzheimer's disease (AD).MethodsIn this 24‐week, multicenter, double‐blind, double‐dummy, placebo‐ and active‐controlled trial, patients with probable AD were randomized to one of four treatment groups: 12 mg/day rivastigmine capsules; 10 cm2 (9.5 mg/24 h) rivastigmine patch; 20 cm2 (17.4 mg/24 h) rivastigmine patch; or placebo. Primary efficacy measures were the Alzheimer's Disease Assessment Scale—Cognitive subscale (ADAS‐Cog) and Alzheimer's Disease Cooperative Study––Clinical Global Impression of Change (ADCS‐CGIC).ResultsOne thousand one hundred and ninety five AD patients from 21 countries participated in the study. Treatment differences (vs placebo) on the ADAS‐Cog at Week 24 in 10 cm2 patch, 20 cm2 patch and capsule groups were 1.6 (p = 0.005), 2.6 (p < 0.001) and 1.6 (p = 0.003). Treatment differences on the ADCS‐CGIC were 0.3 (p = 0.01), 0.2 (p = 0.054) and 0.3 (p = 0.009). Comparison between the 10 cm2 patch and the capsule revealed non‐inferiority. Rates of nausea in the 10 cm2 patch and capsule groups were 7.2% and 23.1%, respectively; rates of vomiting were 6.2% and 17.0%, respectively. Moderate or severe skin irritation occurred in ≤10% patients across the four patch sizes (5, 10, 15 and 20 cm2).ConclusionsThe target dose of 10 cm2 rivastigmine patch provides efficacy similar to the highest doses of capsules with a superior tolerability profile. The transdermal patch with rivastigmine may offer convenience important to many caregivers and patients. Copyright © 2007 John Wiley & Sons, Ltd.
Biomimetic Model of Coenzyme B12: Aquabis(ethane‐1,2‐diamine‐κN,κN′)ethylcobalt(III) – Its Kinetic and Binding Studies with Imidazoles and Amino Acids and Interactions with CT DNA
Authors: Pallavi Ponuganti , Nagababu Penumaka , Satyanarayana Sirasani 
Published: March 2007

AbstractPseudo‐first‐order reaction kinetics and binding studies of trans‐[Co(en)2(Et)H2O] complex with 1H‐imidazole, substituted 1H‐imidazoles, histidine, histamine, glycine and glycine ethyl ester were investigated by means of spectrophotometric techniques. Equilibrium constants were determined as a function of pH at 25°. Binding and kinetic studies were correlated to basicity and steric hindrance. From the equilibrium data, it was found that the entering nucleophile is participating in the transition state, an Id mechanism is proposed. The effect of the incoming ligands on the complex was studied by molecular mechanics. The interaction of trans‐[Co(en)2(Et)H2O] with CT DNA was studied spectrophotometrically.
Hormone replacement therapy and breast cancer in former users of oral contraceptives—The Norwegian Women and Cancer study
Authors: Lund Eiliv , Bakken Kjersti , Dumeaux Vanessa , Andersen Vegard , Kumle Merethe 
Published: March 2007

AbstractCombined estrogen–progestin menopausal therapy (HRT) and combined estrogen–progestin contraceptives (OC) both increase breast cancer risk during current use and a few years after. We investigated risk of breast cancer in women who were users of HRT dependant on former history of OC use in a large, national population‐based cohort study, the Norwegian Women and Cancer study (NOWAC). Exposure information was collected through postal questionnaires. Based on follow‐up of 30,118 postmenopausal women by linkage to national registers of cancer, deaths, and emigration we revealed 540 incident breast cancer cases between 1996 and 2004. Compared to never users of either drugs current use of HRT gave a significant (p = 0.002) higher risk of breast cancer in former OC users, RR = 2.45 (95% CI 1.92–3.12), than among never users of OCs, RR = 1.67 (1.32–2.12). Relative risk of current use of HRT was similar for estrogen only and combinations with progestin added in ever users of OCs. The increased risk of breast cancer in current HRT users with a history of former OC use could have potential great impact on postmenopausal breast cancer risk as the proportion of postmenopausal women with former OC use will continue to increase. © 2007 Wiley‐Liss, Inc.