bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment with CRH‐1 antagonist antalarmin reduces behavioral and endocrine responses to social stressors in marmosets (Callithrix kuhlii)
Authors: French Jeffrey A. , Fite Jeffrey E. , Jensen Heather , Oparowski Katie , Rukstalis Michael R. , Fix Holly , Jones Brenda , Maxwell Heather , Pacer Molly , Power Michael L. , Schulkin Jay
Published: March 2007

Corticotropin‐releasing hormone (CRH) has multiple roles in coordinating the behavioral and endocrine responses to a host of environmental challenges, including social stressors. In the present study we evaluated the role of CRH in mediating responses to a moderate social stressor in Wied's black tufted‐eared marmosets (Callithrix kuhlii). Male and female marmosets (n=14) were administered antalarmin (a selective CRH‐1 receptor antagonist; 50µg/kg, p.o.) or vehicle in a blind, counterbalanced, crossover design. One hr after treatment, marmosets were separated from long‐term pairmates and then housed alone in a novel enclosure for 7 hr. Behavior was recorded during separation and upon reunion with the partner, and urine samples for cortisol assay collected before, during, and after the intervention. Separation from partners elevated urinary cortisol concentrations over baseline for both conditions, but antalarmin treatment reduced the magnitude of the elevation. Antalarmin also lowered rates of behavioral patterns associated with arousal (alarm and “e‐e” vocalizations, object manipulate/chew), but had no effect on contact calls, locomotory activity or alertness. Although most patterns of social behavior upon reunion with the partner were not affected by antalarmin, antalarmin‐treated marmosets displayed more sexual behavior (mounts and copulations) upon reunion. These data indicate that antagonism of the CRH‐1 receptor acts to reduce the magnitude of both endocrine and behavioral responses to a moderate social stressor without causing any overall reduction in alertness or general activity. This supports the hypothesis that CRH, acting through its type 1 receptor, is involved in coordinating the responses to anxiety‐producing events. These results further suggest that the marmoset is a useful model for exploration of the role of CRH in mediating the behavioral and neuroendocrine responses to psychosocial stressors, particularly in the context of heterosexual social relationships. Am. J. Primatol. 69:877–889, 2007. © 2007 Wiley‐Liss, Inc.
Absolute Configuration of Conformationally Flexible cis‐Dihydrodiol Metabolites by the Method of Confrontation of Experimental and Calculated Electronic CD Spectra and Optical Rotations
Authors: Kwit Marcin , Sharma Narain D. , Boyd Derek R. , Gawronski Jacek
Published: March 2007

We have determined the absolute configurations of conformationally flexible cis‐dihydrodiol metabolites (cis‐1,2‐dihydroxy‐3,5‐cyclohexadienes), bearing different substituents (e.g., Br, F, CF3, CN, Me) in 3‐ and 5‐positions, by the method of confrontation of experimental and calculated electronic CD spectra and optical rotations. Convergent results were obtained by both methods in eight out of ten cases. For the difficult cases, where either conformer population and/or chiroptical properties (calculated rotational strengths of the long‐wavelength Cotton effect or optical rotations) of contributing conformers remain inconclusive, the absolute configuration could still be correctly assigned based on one of the biased properties (either ECD or optical rotation). This approach appears well‐suited for a broad spectrum of conformationally flexible chiral molecules.
Infrared Spectrum and Structure of Thorimine (HNThH2)
Authors: Wang Xuefeng , Andrews Lester , Marsden Colin J.
Published: March 2007

Laser‐ablated thorium atoms react with ammonia to form thorimine (NHThH2), the first actinide imine to be reported. This work underscores the high reactivity of thorium atoms, particularly for NH bond activation, reveals a new type of multiple bond to actinide atoms, and shows that this bond is strong for thorium as a result of an important contribution from the f orbitals.
Short‐ vs long‐term androgen suppression plus external beam radiation therapy and survival in men of advanced age with node‐negative high‐risk adenocarcinoma of the prostate
Authors: D'Amico Anthony V. , Denham James W. , Bolla Michel , Collette Laurence , Lamb David S. , Tai Keen‐Hun , Steigler Allison , Chen Ming‐Hui
Published: March 2007

BACKGROUND

The study evaluated whether the use of 3 years as compared with 6 months of androgen suppression therapy (AST) combined with external beam radiation therapy (RT) in the treatment of high‐risk prostate cancer was associated with prolonged survival in advanced age men.

METHODS

A pooled analysis of 311 men enrolled in 3 prospective randomized trials between 1987 and 2000 who received 6 months or 3 years of AST and RT for locally advanced or high‐grade localized adenocarcinoma of the prostate comprised the study cohort. Cox regression multivariable analysis was performed adjusting for known prognostic factors to determine whether the treatment received was associated with time to death after randomization. The median age and follow‐up was 70 and 5.9 years, respectively, during which 82 (26%) deaths occurred.

RESULTS

Treatment received was not significantly associated with survival time after randomization (adjusted hazard ratio [AHR]: 1.1; 95% confidence interval [CI]: 0.7, 1.8; P = .70), whereas age at randomization (AHR: 1.05; 95% CI: 1.01, 1.09; P = .02) was. The presence of Gleason score 8 to 10 cancers approached significance (AHR: 1.6; 95% CI: 0.9, 2.6; P = .09).

CONCLUSIONS

After adjusting for known prognostic factors, the treatment of node‐negative, high‐risk prostate cancer using 3 years as compared with 6 months of AST with RT was not associated with prolonged survival in men of advanced age. The European Organization for Research and Treatment of Cancer randomized trial will help answer whether unknown confounding factors affected the results of the study. Cancer 2007. © 2007 American Cancer Society.
Remarks on the theory of partial differential equations of mixed type and applications to the study of transonic flow
Authors: Germain P.
Published: March 2007

I shall begin by recalling briefly some well known statements on problems arising in the theory of transonic flow. These, from the mathematical point of view, are related to a partial differential equation of the mixed type. But they are not the simplest basic problems of the theory of equations of this type. Although there are close similarities between the study of transonic flow and the mathematical study of mixed equations, one cannot say that the studies are strictly equivalent. The second part of this lecture is devoted to the formation and the study of elementary solutions of equations of this type; a few applications to certain boundary value problems are proposed.
An Electrochemical Alternative Approach to the Cyclization of Alkynes Bearing Proximate Malonyl Moieties
Authors: Arcadi Antonio , Inesi Achille , Marinelli Fabio , Rossi Leucio , Verdecchia Mirella
Published: March 2007

A versatile alternative approach to the synthesis of butenolides, quinolones and 3‐pyrrolin‐2‐ones has been achieved by galvanostatic electrolysis of MeCN/TEATFB solutions and subsequent addition of the cathodic solution to alkynes bearing proximate malonyl moieties. The electrogenerated cyanomethyl anion permits the formation of the reactive anionic intermediates under mild conditions, avoiding the need to use classical bases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electron‐Density Determination of Electrophilic Building Blocks as Model Compounds for Protease Inhibitors
Authors: Grabowsky Simon , Pfeuffer Thomas , Chęcińska Lilianna , Weber Manuela , Morgenroth Wolfgang , Luger Peter , Schirmeister Tanja
Published: March 2007

Three types of synthesised compounds, the aziridine 1, the epoxide 2 and the acceptor‐substituted olefin 3, were chosen as model compounds for electrophilic building blocks, which can covalently block the nucleophilic amino acids of the active sites of proteases (Cys in cysteine proteases or Asp in aspartate proteases). In order to rationally design optimised inhibitors and to understand the differences in inhibition properties of the scrutinised building blocks their structural and electronic properties were studied by ultra‐high resolution X‐ray diffraction and ab initio calculations to yield the experimental electron‐density distribution. It could be shown that the carbon atom C1 of the three‐membered heterocycle is the preferred electrophilic centre for attack of the nucleophiles, which is consistent with the results of corresponding chemical experiments with sulfur and oxygen nucleophiles.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Solvent Effects in the Enantioselective Catalytic‐Phase‐Transfer Alkylation of Polymer‐Supported Glycine–Imine tert‐Butyl Ester: Asymmetric Solid‐Phase Synthesis of (R)‐α‐Amino Acid Derivatives
Authors: Kim Mi‐Jeong , Jew Sang‐sup , Park Hyeung‐geun , Jeong Byeong‐Seon
Published: March 2007

Polymer‐supported glycine–imine tert‐butyl esters (3, 8) were prepared from Merrifield‐ or Wang‐resin and used in the enantioselective synthesis of (R)‐α‐amino acid derivatives by using (S,S)‐3,4,5‐trifluorophenyl‐NAS bromide (5) as the chiral phase‐transfer catalyst. The chemical yields and enantioselectivities were found to be dramatically dependent upon the ratio of water to organic solvent. The optimal solvent was a mixture of toluene/chloroform/water (9:1:0.5). The catalytic enantioselective solid‐phase phase‐transfer alkylation of polymer‐supported glycine–imine substrate 3 with various alkyl halides with the use of 50 % aqueous CsOH in the optimal solvent system at 0 °C followed by hydrolysis and benzoylation afforded the corresponding (R)‐N‐benzoyl‐α‐amino acid tert‐butyl esters 11 in 60–80 % yield and with enantiomeric ratios (er) of 96.5:3.5 to 99.5:0.5.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Synthesis of Molecular Rods with a Transversal Push‐Pull System
Authors: Błaszczyk Alfred , Fischer Matthias , von Hänisch Carsten , Mayor Marcel
Published: March 2007

The design and synthesis of the molecular cruciforms 1–4 consisting of an oligophenylene‐ethynyl backbone with an acetyl‐protected sulfur anchor group on one end and a crossing oligophenylene cross‐bar with terminal trifluoromethyl and dimethylamino groups as transversal push‐pull system are reported. These cruciforms 1–4 are model compounds to investigate electronic potential‐dependent switching properties of molecular junctions. While the oligophenylene‐ethynyl backbone is responsible for the electronic transport properties, the transversal push‐pull system should alter the tilt angle of the rod upon alignment in an electric field. As the tunnel distance at the rods end to the opposite electrode depends on the tilt angle of the rod, a considerable dependence of the transport current on the tilt angle is expected. The investigation of such transport mechanisms with the model compounds 1–4 may unravel the origin of negative differential conductance phenomena in devices consisting of sandwiched self assembled monolayers between two electrodes. The reported cruciform structures display limited stability features in the presence of acids. Their assembly is based on metal catalyzed cross coupling reactions with the chromatographic separation of two, on opposite sides monoprotected regioisomers as key step.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Cationic Rhodium(I)/Bisphosphane Complex‐Catalyzed Isomerization of Secondary Propargylic Alcohols to α,β‐Enones
Authors: Tanaka Ken , Shoji Takeaki , Hirano Masao
Published: March 2007

We have determined that hydrogenated cationic Rh(I)/bisphosphane complexes are highly active catalysts for the isomerization of secondary propargylic alcohols to α,β‐enones. A kinetic resolution of secondary propargylic alcohols proceeded with moderate selectivity with [Rh((R)‐BINAP)]OTf as a catalyst. Mechanistic studies revealed that the isomerization proceeds through intramolecular 1,3‐ and 1,2‐hydrogen migration pathways. The isomerization of propargylic diol derivatives was also investigated, which revealed that 1,4‐diketones, furans, and α,β‐enones were obtained from 2‐butyn‐1,4‐diol, 1‐methoxy‐2‐butyn‐4‐ol, and 1‐acetoxy‐2‐butyn‐4‐ol derivatives, respectively. Furthermore, chemoselectivity of the isomerization of an acetylenic diol was investigated, and preferential oxidation of a propargylic hydroxy group was observed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Speciation and Environmental Fate of Chromium in Rivers Contaminated with Tannery Effluents
Authors: Dominik J. , Vignati D. A. L. , Koukal B. , Pereira de Abreu M.‐H. , Kottelat R. , Szalinska E. , Baś B. , Bobrowski A.
Published: March 2007

Redox and size speciation of chromium in rivers contaminated with tannery wastewater was carried out to provide insight into its transport and removal mechanisms. Total chromium was determined with Inductively Coupled Plasma‐Mass Spectrometry and Cr (VI) with Catalytic Adsorption Stripping Voltammetry. For the size speciation, particles were retained with a cartridge filter (cut‐off 1.2 μm) and the total filterable fraction was further fractionated with Tangential Flow Filtration to determine the concentrations of chromium associated with the High Molecular Weight Colloidal (HMWC), Low Molecular Weight Colloidal (LMWC) and Truly Dissolved (TD) fractions. Two fluvial systems of similar sizes, but located in contrasting climatic zones, were selected for comparison: the Sebou‐Fez system in Morocco and Dunajec River‐Czorsztyn Reservoir system in Poland. Particulate Cr dominated in the Sebou‐Fez system (about 90 %); while in the Dunajec‐Czorsztyn system, it represented only 17–53 % of the total chromium in raw water. Still, the partition coefficients [Kd] were of the same magnitude. Chromium (III) was the only form detected in Sebou‐Fez, whereas in Dunajec‐Czorsztyn Cr (VI) was also present with its proportion increasing downstream from the input of tannery wastewater due to the preferential removal of Cr (III). In the filtered water in Morocco a large fraction of Cr occurred in the HMWC fraction (50–70 %) at the two most contaminated sites, while the LMWC and TD forms prevailed at the non‐contaminated sites in the Sebou River. At a very high concentration, in the water in the proximity of tanneries (well above the theoretical saturation level) Cr precipitated as polynuclear Cr‐hydroxide. In Dunajec‐Czorsztyn, the partition of Cr (III) was approximately equal between the HMWC, LMWC and TD fractions, in contrast to Cr (VI) which occurred almost exclusively in the TD fraction. In both systems, Cr (III) was rapidly removed from the water to the sediments. The confluence of the Sebou with the Fez and the Czorsztyn reservoir trapped efficiently Cr (III) preventing its spreading over long distances. Cr (VI) showed conservative behavior and bypassed the Czorsztyn Reservoir. This study provides a first set of data on the partitioning of Cr (III) and Cr (VI) between the particulate, the colloidal and truly dissolved fractions in fluvial systems contaminated with tannery effluents. It also suggests that, in these systems, truly dissolved Cr (III) can be adequately modeled from the total filterable concentrations.
Discrete crack modelling for dynamically loaded, unreinforced concrete structures
Authors: Skrikerud Petter E. , Bachmann Hugo
Published: March 2007

The dynamic response of unreinforced concrete structures is studied taking account of initiation, extension, closing and reopening of so‐called discrete cracks. The computational procedure is based on the finite‐element method and is at present restricted to two‐dimensional situations. The discrete cracks are simulated by separation of originally adjacent finite elements. An equivalent tensile‐strength criterion is used for the initiation and extension of the cracks which are assumed to propagate perpendicularly to the principal tensile stress. If this direction does not coincide with the interelement boundaries of the finite‐element mesh, the latter is automatically altered. Between elements being separated by a crack special ‘crack elements’ are introduced, which take account of the stress transfer by aggregate interlock. The equations of motion are integrated numerically using an explicit formulation. The procedures outlined are demonstrated on a simplified cross‐section of a concrete gravity dam subjected to horizontal earthquake excitation.
Steady‐state harmonic response of a rigid plate bearing on a liquid‐saturated poroelastic halfspace
Authors: Halpern Marc R. , Christiano Paul
Published: March 2007

Soil–structure interaction problems are typically modelled by assuming subgrade behaviour to be either elastic or viscoelastic. Herein, compliance functions that may be used to solve soil–structure interaction problems are evaluated by treating the subgrade as a liquid‐saturated poroelastic material whose behaviour is governed by Biot's theory.

The compliances are evaluated for the harmonic rocking and vertical motions of rigid permeable and impermeable plates bearing on a poroelastic halfspace. Comparisons are made with elastic solutions which assume the subgrade to be either completely drained or undrained. Also, solid and fluid contact stresses are reported for the poroelastic case and compared to the solid contact stresses for the elastic cases.
A mixed method for transient analysis of soil–structure interaction under SH‐motion
Authors: Eilouch M. N. Alyagshi , Sandhu R. S.
Published: March 2007

A Fourier transform approach is applied to the transient analysis of dynamic soil–structure interaction under SH‐motion. The governing equations are formulated in the frequency domain using a Finite Element–Boundary Element (FE–BE) coupling method. After solving the transformed problem, the transient solution is obtained using the discrete inverse Fourier transform with a fast Fourier transform algorithm. Two examples are presented in order to show the numerical performance of the proposed technique.
Hybrid modelling of a single‐layer half‐space system in SOIL–structure interaction
Authors: Tzong Tsair‐Jyh , Penzien Joseph
Published: March 2007

A hybrid model is applied to two‐dimensional soil–structure interaction problems for the case of a single layer on a halfspace. A continuous impedance function along a semi‐cylindrical interface separating the near and far fields is proposed to simulate the radiation of energy and the energy reflection due to the layer of soil. This function as determined by system identification, together with a near‐field finite element system, provides a solution for the dynamic analysis of any type of structure.
Pipeline response to random ground motion by discrete model
Authors: Datta T. K. , Mashaly E. A.
Published: March 2007

The response of buried pipelines to random excitation by earthquake forces is obtained using a lumped mass model. The earthquake is considered as a stationary random process characterized by a power spectral density function (PSDF). The cross spectral density function between two random inputs along the length of the pipe is defined with the help of the local earthquake PSDF which is the same for all points, and a frequency dependent exponentially decaying (with distance) function. Soil resistance to dynamic excitation along the pipelength is obtained in an approximate manner with the help of frequency independent impedance functions derived from half‐space analysis and Mindlin's static stresses within the soil due to point loads. The proposed method has the advantage that it can take into consideration the cross terms in soil stiffness and damping matrices and can consider any boundary condition that needs to be satisfied at the ends of the pipe. A parametric study is also made to show the influence of cross terms in the soil stiffness and damping matrices on the response of the pipe.
Steady‐state and transient responses of non‐classically damped linear systems
Authors: Ventura Carlos E. , Veletsos Anestis S.
Published: March 2007

A recently proposed procedure for interrelating the steady‐state and transient responses of multi‐degree‐of‐freedom, classically damped linear systems is extended to non‐classically damped systems. The extension is formulated for baseexcited systems, and it is illustrated by simple examples.
Mode‐superposition methods in dynamic analysis of classically and non‐classically damped linear systems
Authors: Borino G. , Muscolino G.
Published: March 2007

Mode‐superposition analysis is an efficient tool for the evaluation of the response of linear systems subjected to dynamic agencies. Two well‐known mode‐superposition methods are available in the literature, the mode‐displacement method and the mode‐acceleration method. Within this frame a method is proposed called a dynamic correction method which evaluates the structural response as the sum of a pseudostatic response, which is the particular solution of the differential equations, and a dynamic correction evaluated using a reduced number of natural modes.

The greater accuracy of the proposed method with respect to the other methods is evidenced through extensive numerical tests, for classically and non‐classically damped systems.
Damping in tall buildings—a mechanism and a predictor
Authors: Jeary A. P.
Published: March 2007

Only when the data base is of sufficient quality can a theoretical model of any process be justified. Such a data base has recently been assembled in the field of damping in tall buildings. It is now possible to specify a damping value appropriate to a particular building vibrating at a specified amplitude which is well correlated with values which are measured in practice. The mechanism on which this predictor is based suggests that the predictor will be applicable to other types of structure as well. As yet the data base for these other structures does not exist, but some circumstantial evidence is encouraging.
Optimum design and earthquake‐response constrained design of elastic shear buildings
Authors: Nakamura Tsuneyoshi , Yamane Takashi
Published: March 2007

The necessary and sufficient conditions for global optimality and the closed form solution are derived for a problem of minimizing a weighted sum of storey stiffnesses of a shear building subject to a fundamental frequency constraint. A set of higher frequency formulae is derived for optimally designed shear buildings with equal masses. It is shown that, if the weight coefficients are regarded as parameters for adjustment, the distribution of the SRSS estimates of the maximum interstorey drifts can be adjusted so as to coincide with a specified one. The base shear–fundamental period formulae and the base shear–design drift formulae are derived semi‐analytically for shear buildings with equal masses on the basis of the optimum design formulae and the SRSS estimates of the maximum interstorey drifts. Some numerical examples are presented in order to illustrate the validity of the proposed method of earthquake‐response constrained design.
Response of a rigid foundation to a spatially random ground motion
Authors: Luco J. E. , Wong H. L.
Published: March 2007

A method to obtain the dynamic response of an extended rigid foundation supported on an elastic half‐space when subjected to a spatially varying ground motion including both random and deterministic effects is presented. The method relies on an integral representation of the response of the foundation in terms of the free‐field ground motion. Numerical results for a rigid square foundation and for a ground motion characterized by a particular spatial coherence function are described. The results obtained indicate that the spatial randomness of the ground motion produces effects similar to the deterministic effects of wave passage including reduction of the translational components of the response at high frequencies and creation of rocking and torsional response components. The possibility of defining an effective apparent horizontal velocity which produces effects equivalent to those from a given spatial randomness is explored.
Response of a circular foundation on a uniform half‐space to elastic waves
Authors: Luco J. E. , Mita A.
Published: March 2007

An alternative technique to obtain the dynamic response of a massless rigid circular foundation resting on a uniform elastic half‐space when subjected to harmonic plane waves is presented. The technique relies on the use of an integral representation involving the free‐field ground motion and the contact tractions obtained in the course of calculating the dynamic force–displacement relationship of the foundation for external forces. Tables listing the translational and rotational components of the response of the foundation for non‐vertically incident SH, P, SV and Rayleigh waves are presented.
Floor response spectra with structure–equipment interaction effects by a mode synthesis approach
Authors: Suarez Luis E. , Singh M. P.
Published: March 2007

A mode synthesis‐based direct approach is presented to calculate seismic response of equipment supported on structures. The approach incorporates the effect of the dynamic interaction between the equipment and the supporting structure. The modal properties of the combined structure–equipment system are obtained by synthesizing the modal properties of the individual structures. The seismic input defined in terms of smoothed ground response spectra can be directly utilized in this approach. Both heavy and light equipment can be considered by the approach equally effectively. Numerical examples demonstrating the effectiveness of the proposed approach are presented.
The non‐linear seismic response of AGR core graphite brick slices—correlation of experimental and analytical results
Authors: Ahmed Khalid , Stojko Stefan
Published: March 2007

It is a requirement for all future nuclear stations in the U.K. that they can be shut down safely in the event of an earthquake.

The AGR reactor core structures have been mathematically modelled using non‐linear techniques which are implemented in the three‐dimensional computer code AGRCOR. Experimental verification of the code has already been determined for a simple one‐dimensional row of graphite brick slices.

This paper discusses the correlation of experimental results with analytical predictions for the dynamic response of a two‐dimensional array of 18 graphite brick slices. The moving structure was excited in a single axis by a common rigid restraint structure in either a sine sweep or dwell mode at constant acceleration. In the paper, descriptions are given of (1) the numerical method; (2) the initial theoretical validation of AGRCOR; (3) the analytical and experimental models; (4) statistical methods used for correlation of results; and (5) the sensitivity of various parameters which control the response of the structure.

The comparisons of experimental absolute brick velocities and interbrick shear forces with the analytical predictions were generally in good agreement. Also the resonant frequencies and instability regions of the brick responses were determined both experimentally and analytically.
Seismic response evaluation of Meloland Road Overpass using 1979 imperial Valley earthquake records
Authors: Werner S. D. , Beck J. L. , Levine M. B.
Published: March 2007

During the 1979 Imperial Valley earthquake, an array of 26 strong‐motion accelerometers produced records for the Meloland Road Overpass, a two‐span reinforced concrete bridge structure located only 0.5 km away from the causative fault for this earthquake event. This paper describes the application of a new system identification methodology to the array of strong‐motion measurements, in order to assess seismic response characteristics of this bridge. Results of this application show that (1) linear models provide an excellent fit to the measured motions of the bridge, despite the fact that it was subjected to very strong shaking; (2) the transverse response of the structure is controlled by its abutment motions, with no significant dynamic amplification in the deck; and (3) the vertical response of the bridge deck at the midlength of its spans is dominated by a single vertical translational mode whereas, above the central pier, the deck's vertical response is most affected by the vertical motions of the pier base and by torsion of the deck. Also, systematic estimates of modal damping ratios and qualitative assessments of states of stress developed in the bridge during the earthquake are provided.
General dynamic‐stiffness matrix of a timoshenko beam for transverse vibrations
Authors: Chen Yung‐Hsiang
Published: March 2007

The general dynamic‐stiffness matrix of a Timoshenko beam for transverse vibrations is presented in this paper. All the effects of rotary inertia of the mass, shear distortion, structural damping, axial force, elastic‐spring and dashpot foundation are taken into account in the formulation. As a consequence, the deflection function of the beam vibration is in complex form, and the nature of the beam vibration and the corresponding dynamic stiffnesses of the beam are characterized by general complex wave numbers. The dynamic‐stiffness matrix for any special case can be derived easily from the general formula, which may be used directly in standard structural analysis.
The coupling effect of axial motion and joint mass on the lateral vibrations of a rigid‐jointed triangular frame
Authors: Kounadis A. N. , Meskouris K.
Published: March 2007

In this investigation, the coupling effects of the axial motion and other parameters on the bending eigenfrequencies and eigenmodes of laterally vibrating frames are re‐examined. To this end an energy variational approach is performed on a rigid‐jointed triangular frame, whose joint mass is eccentrically located with respect to its theoretical position. The governing partial differential equations subject to the appropriate boundary conditions are very conveniently formulated and successfully solved in a closed form by using generalized functions and Laplace transforms. Contrary to the usual assumptions of the standard dynamic analysis of continuous systems, herein the effect of axial contraction and extension is accounted for when establishing the translational kinematic boundary conditions. This may lead to considerable discrepancies that reveal the decisive role of the axial motion effect on the dynamic response of framed structures. Such discrepancies are clearly confirmed through a thorough numerical discussion of the governing parameters: joint mass and its rotatory inertia, joint angle, positioning of the mass, slenderness ratios, stiffness and length ratios.
Code design provisions for torsionally coupled buildings on elastic foundation
Authors: Chandler A. M. , Hutchinson G. L.
Published: March 2007

The effectiveness of the design recommendations made by various major building codes to account for torsional coupling effects is evaluated with respect to the parametric responses to earthquake ground motion of a simple single‐storey asymmetric building model supported on an elastic foundation. The objectives are to determine the extent to which the response trends observed in previous studies of asymmetric rigidly based buildings are affected by changes in the flexibility of the foundation medium and to comment on and suggest necessary amendments to the design recommendations in order that suitable allowance be made for the resultant changes in the magnitude of torsional coupling effects. It is concluded that whilst the qualitative effects of torsional coupling are not affected by soil–structure interaction, their magnitude depends significantly on the frequency content of the free‐field motion. The response to the El Centro earthquake record is conservatively accounted for by assuming the structure to be supported on a rigid foundation. An allowance for increased response effects due to soil–structure interaction is suggested for incorporation in the torsional design recommendations when European earthquake records are employed.
Vertical vibration of three‐dimensional rigid foundations on layered media
Authors: Chow Y. K.
Published: March 2007

A numerical method of analysis is presented for the determination of the steady‐state vertical vibration of rigid foundations with arbitrary three‐dimensional geometries resting on the surface of a layered soil medium. The method utilizes the flexibility concept applied to steady‐state periodic problems and it is solved in the frequency domain. The accuracy of the method is verified by comparison with several published solutions for massless, smooth rigid rectangular foundations on a homogeneous, isotropic elastic half‐space. Parametric solutions are presented to study the dynamic behaviour of massless, smooth rigid rectangular foundations on a homogeneous, elastic stratum.
Use of seismic data from similar regions
Authors: Rosenblueth Emilio , Ordaz Mario
Published: March 2007

Attention is first focused on the probability distributions of the exceedance rates of given earthquake magnitudes when the generation process is idealized as Poisson. But data on significant disturbances are always scarce. Local‐seismicity assessment is hence guided by information from tectonically similar areas, but ordinarily the guidance is intuitive. Bayesian statistics constitute the tool to do this rationally. Two more alternatives are presented and illustrated here. The approach is extended to a generating process that includes the Poisson as a special case.
The soft‐output principle—reminiscences and new developments
Authors: Hoeher Peter A. , Robertson Patrick , Offer Elke , Woerz Thomas
Published: March 2007

A major breakthrough in digital communications was the provisioning of ‘soft’ outputs at each processing stage, with appropriate capabilities to use this as soft inputs in the next processing stage. This allowed for much more performant receivers especially in difficult mobile radio channel conditions, and set the stage for iterative processing. This article will outline the development of soft output algorithms over the last two decades along with associated state‐of‐the‐art applications and conclude with an outlook towards novel applications of the soft principle. Copyright © 2007 John Wiley & Sons, Ltd.
Maternal experience inhibits the production of immature neurons in the hippocampus during the postpartum period through elevations in adrenal steroids
Authors: Leuner Benedetta , Mirescu Christian , Noiman Liron , Gould Elizabeth
Published: March 2007

Motherhood is accompanied by alterations in numerous nonreproductive behaviors, including learning and memory, as well as anxiety and stress regulation. These functions have been linked to adult neurogenesis in the hippocampus, but the effect of maternal experience on this brain region has not been completely explored. To determine whether the production of new hippocampal granule cells is altered during the postpartum period, we examined the number of proliferating cells and their progeny in the dentate gyrus of primiparous female rats at various time points during the postpartum period while they were caring for their offspring, as well as after weaning. Additionally, we investigated whether cell proliferation in the postpartum female is affected by the presence of offspring and nursing‐induced increases in glucocorticoids. Analysis of the number of BrdU‐labeled cells revealed that cell proliferation in the dentate gyrus was suppressed in lactating postpartum females until the time of weaning. This effect was temporary; a difference was detectable at 1 week after BrdU‐labeling, when the majority of cells expressed a marker of immature and mature granule neurons (TuJ1) but not at 2 weeks, when most cells expressed a marker of mature neurons (NeuN). The decrease in cell proliferation was dependent on elevated basal glucocorticoid levels associated with lactation; removal of nursing pups reduced basal corticosterone levels and prevented the decrease in the number of BrdU‐labeled cells. Moreover, preventing increased basal corticosterone levels by means of adrenalectomy and low‐dose corticosterone replacement eliminated the reduction in cell proliferation. These findings indicate that offspring interactions inhibit adult neurogenesis through changes in adrenal steroids, and further suggest a potential mechanism for alterations in hippocampal function during the postpartum period. © 2007 Wiley‐Liss, Inc.
Ameliorative effects of a neuroprotective agent, T‐817MA, on place learning deficits induced by continuous infusion of amyloid‐β peptide (1–40) in rats
Authors: Nguyen Phuong Thi Hong , Kimura Tatsuo , Ho Son Anh , Tran Anh Hai , Ono Taketoshi , Nishijo Hisao
Published: March 2007

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive decline due to neuronal loss and neural network dysfunction. It has been postulated that progressive neuronal loss in AD is consequence of the neurotoxic properties of the amyloid‐β peptide (Aβ). In the present study, we investigated the effect of T‐817MA (1‐{3‐[2‐(1‐benzothiophen‐5‐yl)ethoxy] propyl}‐3‐azetidinol maleate), a newly synthesized neurotrophic compound, on place learning deficits in rats with hippocampal damages. To induce granule cell loss in the dentate gyrus (DG) of the hippocampus, Aβ (1–40) was continuously infused (300 pmol/day) into the cerebral ventricle using a mini‐osmotic pump for 5 weeks. Three weeks after the Aβ infusion, the rats were tested in a place learning task, which required them to alternatively visit two diametrically opposed areas in an open field to obtain intracranial self‐stimulation reward. The results indicated that the Aβ‐infused rats without treatment of T‐817MA displayed learning impairment in the task; their performance level was significantly inferior to that of the vehicle rats. Treatment of T‐817MA (8.4 mg/kg/day, p.o.) significantly improved the task performance of the Aβ‐infused rats. Furthermore, T‐817MA prevented granule cell loss due to Aβ‐infusion, which was correlated to task performance of the rats. However, other cognitive enhancer, an acetylcholinesterase inhibitor, had no such effects. The results demonstrated that T‐817MA ameliorated learning deficits induced by Aβ infusion, which might be attributed to neuroprotection in the hippocampus. © 2007 Wiley‐Liss, Inc.
Signs of proinflammatory/genotoxic switch (adipogenotoxicosis) in mammary fat of breast cancer patients: Role of menopausal status, estrogens and hyperglycemia
Authors: Berstein Lev M. , Kovalevskij Anatolij Y. , Poroshina Tatjana E. , Kotov Alexander V. , Kovalenko Irina G. , Tsyrlina Evgenia V. , Leenman Elena E. , Revskoy Sergey Y. , Semiglazov Vladimir F. , Pozharisski Kazimir M.
Published: March 2007

The abundance of fat tissue surrounding normal and malignant epithelial mammary cells raises the questions whether such “adipose milieu” is important in the local proinflammatory/genotoxic shift, which apparently promotes tumor development and worsens prognosis, and what conditions stimulate this shift, or “adipogenotoxicosis.” We studied 95 mammary fat samples from 70 postmenopausal and 25 premenopausal breast cancer (BC) patients at a distance of 1.5–2.0 cm from tumors. The levels of leptin, adiponectin, TNFα and IL‐6 release after 4‐hr incubation of the samples were evaluated with ELISA, nitric oxide (NO) production by Griess reaction and lipid peroxidation by determination of thiobarbiturate‐reactive products (TBRP). Infiltration of fat with macrophages (CD68‐positive cells) and expression of cytochrome P450 1B1/estrogen 4‐hydroxylase (CYP1B1) were detected by immunohistochemistry. Aromatase (CYP19) activity in mammary fat was measured by 3H2O release from 3H‐1β‐androstenedione. In the postmenopausal BC patients, NO and TNFα production by adipose tissue explants increased independent of BMI and in parallel with decreasing leptin and, especially, adiponectin release. In the premenopausal patients, higher CYP1B1 expression and TBRP level were found in mammary fat, while higher aromatase activity was combined with higher CYP1B1 expression as well as NO and IL‐6 production. In the postmenopausal group, impaired glucose tolerance was associated with higher IL‐6 release production by fat and with higher IL‐6/adiponectin ratio. Thus, signs of adipogenotoxicosis in mammary fat can be found in both pre‐ and postmenopausal BC patients. This condition is likely being maintained through estrogen‐ and glucose‐related factors and mechanisms presumably associated with less favorable types of hormonal carcinogenesis. © 2007 Wiley‐Liss, Inc.
Benefit of sentinel lymphadenectomy for patients with nonulcerated cutaneous melanomas in the Breslow range between 0.76 and 1 mm: A follow‐up study of 148 patients
Authors: Starz Hans , Balda Bernd‐Ruediger
Published: March 2007

Sentinel lymphadenectomy (SLNE) is now internationally accepted for the primary treatment of melanomas thicker than 1 mm. But it is still controversial whether also patients with nonulcerated melanomas in the Breslow range between 0.76 and 1 mm should be included. At the authors' department, 87 of such patients (Group A) underwent SLNE in combination with wide local excision (WLE) of their primary melanomas in the years 1995 to 2001. SLN micrometastases were found in 10 of these patients (11.5%). Radical completion lymph node dissections (CLND) were added in 4 of the 10 patients without revealing any further nodal metastases. All the 87 Group A patients remained free from recurrent disease at a median follow‐up time of 74 months. The control Group B from the same department encompassed 61 consecutive stage Ia patients with melanomas in the identical Breslow range, who had undergone only WLE of their primaries without SLNE in the years 1987 to 1993 (median follow‐up time 115 months). Five of these 61 patients (8.2%) developed melanoma metastases within 12 to 68 (median 19) months of follow‐up, 3 of them initially in regional lymph nodes. Four of the 5 individuals died because of the final distant dissemination of the melanoma. Kaplan–Meier comparisons between Groups A and B with log‐rank testing showed a significantly worse outcome of Group B with respect to recurrence‐free survival (p = 0.01), regional nodal progression (p = 0.041), distant metastasis (p = 0.023) and melanoma‐related mortality (p = 0.03). The overall survival was not significantly different, because expiries not related to melanoma predominated in both groups. Our data suggest that SLNE seems to nearly completely eliminate the risk of melanoma recurrences in patients with melanomas between 0.76 and 1 mm thick. © 2007 Wiley‐Liss, Inc.
Tribological investigation of novel HDPE‐HAp‐Al2O3 hybrid biocomposites against steel under dry and simulated body fluid condition
Authors: Nath Shekhar , Bodhak Subhadip , Basu Bikramjit
Published: March 2007

Among various biocompatible polymers, polyethylene based materials have received wider attention because of its excellent stability in body fluid, inertness, and easy formability. Attempts have been made to improve their physical properties (modulus/strength) to enable them to be used as load bearing hard tissue replacement applications. Among such attempts, high density polyethylene (HDPE)‐hydroxyapatite (HAp) composite (HAPEXTM), has already been developed for total hip replacement (THR) acetabular cup and low load bearing bone tissue replacement. In the present work, alumina has been added as a partial replacement of HAp phase to improve the mechanical and tribological properties of the HAPEX composite. In an attempt to assess the suitability of the developed composite in THR application, the tribological properties against steel counterbody under both in air and simulated body fluid (SBF), have been investigated and efforts have been made to understand the wear mechanisms. The fretting wear study indicates the possibility of achieving extremely low COF (Coefficient of Friction ∼0.09) as well as higher wear resistance (order of 10−6 mm3/N m) with the newly developed composites in SBF. A low wear depth of ∼4.6−5.3 μm is recorded, irrespective of fretting environment. The implication of the work is that optimal and combined addition of bioactive and bioinert ceramic filler to HDPE can provide a good opportunity to obtain hybrid biocomposites with better combination of physical properties (modulus, hardness) as well as low friction and high wear resistance. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Semiovals contained in the union of three concurrent lines
Authors: Blokhuis Aart , Kiss Győrgy , Kovács István , Malnič Aleksander , Marušič Dragan , Ruff János
Published: March 2007

Semiovals which are contained in the union of three concurrent lines are studied. The notion of a strong semioval is introduced, and a complete classification of these objects in PG(2,p) and PG(2,p2), p an odd prime, is given. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 491–501, 2007
A new approach for numerical simulation of quantum transport in double‐gate SOI
Authors: Abdolkader Tarek M.
Published: March 2007

Numerical simulation of nanoscale double‐gate SOI (Silicon‐on‐Insulator) greatly depends on the accurate representation of quantum mechanical effects. These effects include, mainly, the quantum confinement of carriers by gate‐oxides in the direction normal to the interfaces, and the quantum transport of carriers along the channel. In a previous work, the use of transfer matrix method (TMM) was proposed for the simulation of the first effect. In this work, TMM is proposed to be used for the solution of Schrodinger equation with open boundary conditions to simulate the second quantum‐mechanical effect. Transport properties such as transmission probability, carrier concentration, and I–V characteristics resulting from quantum transport simulation using TMM are compared with that using the traditional tight‐binding model (TBM). Comparison showed that, when the same mesh size is used in both methods, TMM gives more accurate results than TBM. Copyright © 2007 John Wiley & Sons, Ltd.
Glial fibrillary acidic protein‐expressing cells in the neurogenic regions in normal and injured adult brains
Authors: Zhu Hong , Dahlström Annica
Published: March 2007

In the adult brain, neurogenic stem cells are prevalent in the subventricular zone (SVZ) of the lateral ventricle wall and the subgranular zone (SGZ) in the dentate gyrus. Cells that have structural and molecular characteristics of astrocytes function as neurogenic stem cells in these regions, in which these cells also participate in the creation of the microenvironment that stimulates neurogenesis. In the present paper, we review the phenotypic properties, subpopulations, and proliferation of glial fibrillary acidic protein (GFAP)‐expressing cells in these two neurogenic regions and their responses to different brain injuries. Cells fulfilling the criteria for astrocytes, i.e., expressing GFAP, in the SVZ and SGZ respond differently to brain injuries or neurogenic stimuli. The importance of guidance by astrocytes of newly formed neuronal cells is emphasized. The assessment of GFAP‐expressing cells in the neurogenic regions is of great importance for understanding the mechanism underlying the response of neural stem cells to brain injury. © 2007 Wiley‐Liss, Inc.