bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppressive effect of paroxetine, a selective serotonin uptake inhibitor, on tetrahydrobiopterin levels and dopamine as well as serotonin turnover in the mesoprefrontal system of mice
Authors: Miura Hideki , Kitagami Tomitsune , Ozaki Norio 
Published: June 2007

AbstractTetrahydrobiopterin (BH4) is a coenzyme of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), which are rate‐limiting enzymes of monoamine biosynthesis. According to the monoamine hypothesis of depression, antidepressants will restore the function of the brain monoaminergic system and the BH4 concentration. In the present study, we investigated the effect of paroxetine, a selective serotonin reuptake inhibitor (SSRI), on the BH4 levels and dopamine (DA) and serotonin (5‐HT) turnover in the mesoprefrontal system, incorporating two risk factors of depression, social isolation and acute environmental change. Male ddY mice (8W) were divided into two housing groups, i.e., group‐housing (eight animals per cage; 28 days), and isolation‐housing (one per cage; 28 days), being p.o.‐administered paroxetine (5 or 10 mg/kg; days 15–28), and exposed to a 20‐min novelty stress (day 28). The levels of BH4, DA, homovanilic acid (HVA), 5‐HT, and 5‐hydroxyindoleacetic acid (5‐HIAA) were measured in the prefrontal cortex and midbrain. In both the regions, novelty stress significantly increased BH4 levels under the isolation‐housing condition, whereas these levels were decreased under the group‐housing condition. Thus, social isolation altered the neurochemical response to novelty stress. Paroxetine significantly decreased BH4 levels under the isolation‐housing condition, whereas decreased HVA/DA and 5‐HIAA/5‐HT ratios were observed under the group‐housing condition. Thus, social isolation may have influenced the suppressive effects of paroxetine on BH4 levels as well as exerted an influence on DA and 5‐HT turnover. We replicated our recent findings that SSRI, fluvoxamine, suppressed BH4 levels, as well as DA and 5‐HT turnover in the mouse mesoprefrontal system. Synapse 61:698–706, 2007. © 2007 Wiley‐Liss, Inc.
Effects of increased endogenous serotonin on the in vivo binding of [11C]DASB to serotonin transporters in conscious monkey brain
Authors: Yamamoto Shigeyuki , Onoe Hirotaka , Tsukada Hideo , Watanabe Yasuyoshi 
Published: June 2007

AbstractUsing a combination of positron emission tomography (PET) and the microdialysis technique, the effects of increased endogenous serotonin (5‐hydroxytryptamine; 5‐HT) on the binding of [11C]DASB to 5‐HT transporters (5‐HTT) were investigated in the conscious monkey brain. Five rhesus monkeys (Macaca mulatta) were scanned with [11C]DASB under the control condition and the increased endogenous 5‐HT condition, in which 5‐hydroxy‐L‐tryptophan (5‐HTP) was administered (20 mg/kg, i.v.) before the PET scan. Compared with the control scan, the 5‐HTP administration significantly decreased the binding potential (BP) (BP = Bmax/Kd) of [11C]DASB in several brain regions. The mean % decrease of BP was biggest in the caudate and putamen. Two monkeys were scanned with [11C]5‐HTP to assess the amino acid decarboxylase (AADC) activity in the brain, resulting in the high activity in the caudate and putamen. Microdialysis measurements showed that although 5‐HTP administration (20 mg/kg, i.v.) increased the extracellular 5‐HT levels in both the prefrontal cortex and caudate, the increase of the 5‐HT level in the caudate was 27 times higher than that in the prefrontal cortex. These results suggest that the caudate and putamen, both of which show high AADC activity, convert 5‐HTP to 5‐HT at a high rate, and the increased 5‐HT competes with [11C]DASB for the 5‐HTT. Synapse 61:724–731, 2007. © 2007 Wiley‐Liss, Inc.
A direct method for ultrasound prediction of day of delivery: a new, population‐based approach
Authors: Gjessing H. K. , Grøttum P. , Eik‐Nes S. H. 
Published: June 2007

AbstractObjectivesTo introduce a direct population‐based method for prediction of term based on ultrasound measurements of the biparietal diameter and femur length in the second trimester of pregnancy.MethodsOur data consisted of 41 343 ultrasound scans from a non‐selected population, prospectively collected during the years 1987–2004. Using measurements of biparietal diameter and femur length, we constructed prediction curves for term by computing median remaining time of pregnancy from the ultrasound measurement to birth. A local linear quantile regression method was used to smooth the median and quantile curves.ResultsThe quality of term prediction was stable over the prediction range for both biparietal diameter (25–60 mm) and femur length (11–42 mm). The femur‐based predictions were nearly as good as those of the biparietal diameter. For the biparietal diameter, the median of the prediction residual was − 0.09 days; 87.2% of the births fell within ± 14 days of the predicted day of delivery, 3.5% births were classified as preterm and 4.3% as post‐term. The corresponding figures for femur length were − 0.04 days, 86.7%, 3.6% and 4.5%. The covariates maternal age, parity, mother's smoking habits, sex of the fetus and examination year generally affected the predicted term by less than 1 day.ConclusionsThis direct ultrasound‐based prediction of term using population‐based data avoids selection biases possibly present in smaller prospective samples. The model obviates the dependence on last menstrual period found in standard methods for term prediction, and allows an immediate assessment of prediction quality in a population setting. The femur‐based predictions had a quality similar to those based on the biparietal diameter. The model can be updated continuously as new data are collected. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Eine einheitliche Herleitung verschiedener Interpolationsformeln mittels der Taylorschen Formel der Operatorenrechnung
Authors: Tasche M. 
Published: June 2007

AbstractZahlreiche Verfahren der numerischen Differentiation und Integration basieren auf Interpolationsmethoden oder Polynomentwicklungen. Deshalb ist eine einheitliche Herleitung von Interpolationsformeln und Polynomentwicklungen und entsprechenden Fehlerabschätzungen von Interesse. In der vorliegenden Arbeit lösen wir dieses Problem mittels der Taylorschen Formel der Operatorenrechnung. Dabei wird die Operatorenrechnung als Teilgebiet der Theorie der verallgemeinert inversen Operatoren verstanden.
Gas‐Particulate Flow through a Curved Pipe
Authors: Jain R. K. , Prabha Saroj 
Published: June 2007

AbstractGas‐particulate flow through the curved pipe is analyzed in order to study the effect of the secondary flow on the volume flow rate at given pressure gradient. It is observed that as the secondary flow through the pipe increases, volume flour rate decreases. Moreover, when the particles are fine, the volume flow rate for the clean gas is greater than the volume flow rate for gas‐particulate flow. For coarse particles, volume flow rate for gas‐particulate flow is greater than the volume flow rate for the clean gas.
Zum Problem des gegenseitigen Einflusses von selbsterregten und fremderregten Schwingungen
Authors: Tondl A. 
Published: June 2007

AbstractDiese Studie ist ein Beitrag zur Analyse der gegenseitigen Wirkung von selbsterregten und fremderregten Schwingungen eines Systems mit einem Freiheitsgrad und einer nichtlinearen Federcharakteristik. Es wird sowohl der Fall der weichen als auch der der harten Selbsterregung untersucht. Die Stabilität und die reale Existenz der semitrivialen und nichttrivialen Lösungen (d. h. der Lösungen, die sowohl Komponenten der selbsterregten als auch der fremderregten Schwingungen enthalten) werden in Resonanz analysiert.
On the Behavior of Plates Laminated of Bimodulus Composite Materials
Authors: Reddy J. N. , Bert C. W. 
Published: June 2007

AbstractAn excet and finite‐element analysis is used to predict the static bending and natural vibration response of rectangular plates laminated of composite material having different elastic properties depending upon whether the fiber‐direction strains are tensile or compressive. The analysis is based on a theory that accounts for anisotropy, bending‐stretching coupling, thickness shear deformation, and both coupling inertia und rotatory inertia. The finite‐element results are found to agree very closely with the exact closed‐form solutions in the case of a cross‐ply rectangular plate having simply supported edges and subjected to sinusoidally distributed normal‐pressure loading or temperature loading.
The Newtonian Two‐Fluid Model and Stationary Flow in Cylindrical Tubes of Varying Radius
Authors: Perkkiö J. 
Published: June 2007

AbstractThe stationary and laminar flow of two immiscible Newtonian fluids with equal density and different viscosities in cylindrical tubes with varying radius is considered. The expressions of the wall shearing stress and the flow resistance are calculated. The results are applied to flow through locally constricted tubes, for example to the flow of blood in blood vessel with stenosis.
Fehlerschätzung und Nachiteration bei Galerkin‐Verfahren
Authors: Lippold G. 
Published: June 2007

AbstractZur Schätzung der lokalen Diskretisierungsfehler in Galerkin‐Verfahren für lineare Gleichungen mit stark positiven Operatoren verwenden wir die Defekte von Näherungslösungen in genaueren Gleichungen. Durch die Wahl geeigneter Galerkin‐Schemata kann auf spezielle in der Literatur bekannte Glättungsprozesse verzichtet werden.
Das hydraulische Modell eines Plasmas in einem z‐Pinch
Authors: Förste J. 
Published: June 2007

AbstractUnter gewissen Bedingungen kann die Strömung in einer Plasmasäule im Rahmen einer hydraulischen Näherung beschrieben werden. Dabei hängen die Strömungsparameter U, V, N und R nur von der axialen Koordinate z und der Zeit t ab. U und V sind dabei die Geschwindigkeitskomponenten in z‐Richtung bzw. senkrecht dazu, N ist die Dichte und R die radiale Ausdehnung. Für diese Größen ergibt sich aus den Grundgleichungen der Magnetohydrodynamik ein Rand‐Anfangswert‐Problem; für dieses werden Existenz‐ und Einzigkeitsaussagen bewiesen.
Schwingungsinduzierte Durchflußänderung im Ringraum zwischen konzentrischen Rohren
Authors: Müller H. 
Published: June 2007

AbstractIm Ringraum zwischen konzentrischen Rohren fließe inkompressible newtonsche Flüssigkeit in axialer Richtung. Durch harmonische Querschwingungen des Innenzylinders wird eine Veränderung des nunmehr zeitlich gemittelten Volumenstromes bei gleichbleibendem Druckgradienten bewirkt, deren Berechnung im Rahmen einer Störungstheorie Ziel dieser Arbeit ist. Es zeigt sich, daß im Fall langsamer Schwingungen Volumenstromerhöhung, im Fall schneller Schwingungen Volumenstromminderung eintritt. Im Bereich mittlerer Frequenzen findet ein monotoner Übergang zwischen diesen Extremzuständen statt. Die Effekte sind um so stärker, je enger der Spalt zwischen den Rohren ist, d. h. je näher deren Radienverhältnis bei 1 liegt.
Flow in a Cylindrical Tube with sudden Change of Suction Across the Wall
Authors: Bauer Helmut F. 
Published: June 2007

AbstractIn a permeable circular cylindrical tube with constant suction across the wall the constant radial flow velocity at the wall is suddenly changed to another constant value. The transient flow behavior, such as the velocity‐, stress‐ and pressure distribution are presented analytically. Many special cases of interest to engineering and biological processes may be obtained.
Impact of a Body on a Mass Attached to an Elastically Restrained Beam
Authors: Kounadis A. N. 
Published: June 2007

AbstractAn extension of the classical problem of transverse impact of a body striking with an initial velocity on a beam, is presented. The individual and coupling effects on the dynamic response of the beam are discussed for a number of parameters such as: attached masses (position, translational and rotational inertia), elastic spring supports, and height of free fall of the body. A powerfull and quick analytical procedure leading to a closed form solution is developed which is demonstrated through numerous examples. An additional advantage of the proposed procedure is that an upper bound for the maximum value of any displacement or stress component can be readily established by means of the eigenfrequencies.
Sudden Twisting of an Infinite Elastic Conductor with a Penny‐Shaped Crack in a Constant Axial Magnetic Field
Authors: Shindo Y. 
Published: June 2007

AbstractThe problem of a torque applied suddenly to the surface of a penny‐shaped crack in an infinite elastic conductor permeated by a uniform axial magnetic field is considered. The singular solution is equivalent to that of the sudden appearence of a crack in a body under torsion. We discuss two special cases here. First, the quasistatic electromagnetic field is considered. Laplace and Fourier transforms are used to reduce the problem to a pair of dual integral equations. The solution to the dual integral equations is expressed in terms of a Fredholm integral equation of the second kind having the kernel that is a finite integral. The dynamic singular stress distributions near the crack tip are obtained in closed forms and the influence of the magnetic field upon the dynamic stress‐intensity factors is shown graphically. Second, perfect conductivity is also considered.
On a Model of a Polycondensation Process with Thermal Degradation
Authors: Gajewski H. , Sparing H.‐D. 
Published: June 2007

AbstractA mathematical model of the melt polycondensation of polyethylene terephthalate respecting degradation reaction is considered. In the framework of this model simple approximate formulas for predicting the temporal evolution of the average degree of polymerization are established.
Monoton einschließende Verfahren bei additiv zerlegbaren Gleichungen
Authors: Schmidt H J. W. , Schneider  
Published: June 2007

AbstractZur monotonen Lösungseinschließung bei nichtlinearen Gleichungen wird eine Klasse von Verfahren entwickelt, welche als wichtige Sonderfälle Verfahren vom Newton‐, Regula falsi‐ und Jacobi‐Newton‐Typ enthält. In Abschwächung üblicher Monotonieforderungen wird dabei zugelassen, daß sich die Gleichung in Summanden mit unterschiedlichem Monotonieverhalten zerlegen läßt.
On Control‐Approximation Problems in Hilbert Spaces and Related Dual Problems: Subdifferentiability Properties and Estimates
Authors: Dietze S. 
Published: June 2007

AbstractIn this paper we consider abstract control‐approximation problems in Hilbert spaces, related dual problems and equivalent problems which arise from optimality conditions. We give the connections between these problems and study several properties of them, particularly properties concerning the subdifferentiability of the cost functionals. Furthermore, we derive estimates for the solutions and the optimal functional values. The results of this paper are above all useful for solving the control‐approximation problems, by the aid of the dual problems, directly or in connection with regularization methods.
Bemerkungen zur Instabilität der Strömung nicht‐newtonscher Flüssigkeiten
Authors: Becker E. 
Published: June 2007

AbstractIn nicht‐newtonschen Flüssigkeiten kann eine Instabilität bei schleichender Strömung auftreten. Die Energiemethode zur Stabilitätsuntersuchung liefert hierfür ein Stabilitätskriterium, vorausgesetzt, man kennt das Stoffgesetz der Flüssigkeit. Es wird gezeigt, wie man sich eine relevante Stoffgleichung, ausgehend von der Grundströmung, deren Stabilität zu untersuchen ist, durch ein Störungsverfahren verschaffen kann. Am Beispiel ebener viskometrischer Grundströmung wird unter Beschränkung auf ebene Störungen ein einfaches, experimentell gut bestätigtes Ergebnis für die Stabilitätsgrenze hergeleitet.
Strukturelles Deformationsmodell räumlich armierter Verbundwerkstoffe
Authors: Teters G. A. , Kregers A. F. 
Published: June 2007

AbstractAusgehend von der Mittelungsmethode der Theorie lokaler Deformationen wird ein mathematisches Modell räumlich armierter Kompositwerkstoffe konstruiert. Aus den gegebenen Eigenschaften der Armierung, des Matrixmaterials und der Armierungsgeometrie werden die Deformationen eines charakteristischen Strukturelements bestimmt. Die Berechnung der Deformationseigenschaften wird durch die Mittelung der Spannungen bzw. der Dehnungen des charakteristischen Strukturelements durchgeführt. Die erhaltenen Ergebnisse werden mit experimentellen Daten verglichen.
Diskretisierungsverfahren zur Lösung singulär gestörter Randwertprobleme
Authors: Tobiska L. 
Published: June 2007

AbstractIn der vorliegenden Arbeit wird die Konvergenz und Stabilität von Diskretisierungsverfahren für singulär gestörte Zweipunktrandwertaufgaben untersucht. Einige Resultate lassen sich auf den zweidimensionalen Fall übertragen. Darüberhinaus wird die Konvergenz im globalen Gebiet (ohne Grenzschichten) untersucht.
On the Hill's Fundamental Equation for Quasihomogeneous Materials
Authors: Kafka V. 
Published: June 2007

AbstractThe well known Hill's equation (1) that is of fundamental meaning for the analysis of quasihomogeneous materials, is discussed and proved on the basis of assumptions that describe the macroscopic behaviour of these materials, i.e. on the basis of their definition. It is shown that an analogous equation where the volume averages are meant not in the composite but in one material constituent only, is not valid.
Analysis of Chebyshev Relaxation in Multigrid Methods for Nonlinear Parabolic Differential Equations
Authors: van der Houwen P. J. , Sommeijer B. P. 
Published: June 2007

AbstractThe main purpose of this paper is the analysis of the behaviour of (nonlinear) Chebyshev relaxation in multigrid methods for solving the implicit relations obtained when an implicit linear multistep method is applied to the space‐discretized parabolic differential equation. The relaxation parameters are tuned to those frequencies in the iteration error which one wants to damp on the successive grids. The coarsest grid problem, being related to the semi‐discrete parabolic equation on the coarsest grid, is solved by a stabilized Runge‐Kutta method. Numerical experiments and comparison with Gauss‐Seidel relaxation are reported.
Die exakte Berechnung der Moore‐Penrose‐Inversen einer Matrix durch Residuenarithmetik
Authors: Springer J. 
Published: June 2007

AbstractMit Hilfe der Residuenarithmetik können Matrixinverse und Lösungen von linearen Gleichungssystemen exakt (rundungsfehlerfrei) berechnet werden. Nach einer kurzen Einführung in die Residuenarithmetik und einem Überblick über bisher erzielte Ergebnisse wird in dieser Arbeit eine neue und effektivere Methode zur exakten Berechnung der Moore‐Penrose‐Inversen A+ einer ganzzahligen Matrix A beschrieben. Sie beruht auf neuen Formeln für einen gemeinsamen ganzzahligen Nenner der (rationalen) Elemente von A+. Das Verfahren kann auch zur Lösung allgemeiner linearer Gleichungssysteme verwendet werden.
Pulsatile Flow in a Rotating Duct of Varying Gap
Authors: Goswami B. , Nanda R. S. 
Published: June 2007

AbstractThe problem of pulsatile flow in a duct of varying gap rotating with an angular velocity Ω about an axis perpendicular to the axis of the duct is analysed. Boundary layer approximations are invoked and the resulting equations are solved by a process of sucessive approximations. The first order harmonic and the second order steady mean velocity and pressures are obtained. The overall behaviour of the solution is characterised by two parameters X2 = Ωa2/v and α = ωa2/v where a is the mean half width of the channel, ω the frequency of oscillation and v is the kinematic viscosity. The details of the response of the fluid to the imposed oscillations are examined.
Monotonicity Methods for Nonlinear Singular Integral and Integro‐Differential Equations
Authors: Wolfersdorf L. V. 
Published: June 2007

AbstractApplying methods of monotone operator theory existence theorems are proved for some classes of nonlinear singular integral and integro differential equations of Cauchy's type. In particular there are admitted more general nonlinearities in the considered integral equations than in the existing literature.
The Acceleration of Fast Deflagration Waves
Authors: Stewarta D. S. , Ludford G. S. S. 
Published: June 2007

AbstractIn an earlier paper Stewart and Ludford gave a theory of steady deflagration waves based on an ignition‐temperature model obtained from Arrhenius kinetics. They were able to describe analytically the structure of deflagration waves for the entire range of wave speeds between zero and the maximum (Chapman‐Jouget) value. In this paper we construct a quasisteady theory of flame acceleration based on that work, which can predict the acceleration response of a preexisting flame to quite arbitrary hydrodynamic disturbances in the limit of small heat release during the combustion. Explicit formulas and criteria are developed. In particular, we find that an unsteady deflagration wave can travel at speeds in excess of the Chapman‐Jouget value, and even at arbitrarily large supersonic values.
Three‐Dimensional Thermoelastic Treatment in Spherical Region and its Application to Solid Sphere due to Rotating Heat Source
Authors: Tanigawa Yoshinobu , Takeuti Yoitiro 
Published: June 2007

AbstractThis paper is concerned with three‐dimensional thermoelastic treatment governed by spherical coordinate system. The first part in this paper is devoted to derive the convenient expressions for the displacements and stress components by introducing two functions obtained from the three‐dimensional field equations of motion. It is shown that one of them is harmonic, and the other one is a solution of Poisson's equation. In the latter part, we have applied the above treatment to a practical three‐dimensional thermoelastic problem. As an illustrative example, we have analyzed the thermal stress problem of a solid sphere due to rotating heat source, and carried out the numerical calculation.
Relaxationsprozesse in Aerosolströmungen mit polydisperser Partikelphase
Authors: Roth P. , Thielen K. 
Published: June 2007

AbstractStarting from the principles of the two‐phase‐flow theory the relaxation process of an aerosol with very small polydisperse solid particles behind shock waves has been studied. Different size distributions of the particles in the initial state have been assumed. The overall volume concentration of the particles should be small. Therefore the exchange processes between the phases have a weak influence on the gas phase, only. For the momentum and heat transfer processes molecular effects have been taken into account by simple Knudsen number corrections. Different computations show the time‐dependent deformation of the particle size distribution function during the aerosol relaxation behind shock waves.
Computation of Imperfection‐Sensitivity at Two‐Fold Branching Points
Authors: Gáspár Z. 
Published: June 2007

AbstractThere is a degenerate critical point (usually elliptic or hyperbolic umbilic) of the potential function of semisymmetric conservative systems in the case of a two‐fold branching point. The bifurcation set of a standard form is known in both cases in a parametrized form. In an imperfection‐sensitivity examination the relevant critical point is regarded as the first one reached by a continuously changing load, starting from a stable equilibrium state. The coordinate system of the imperfection‐sensitivity surface is transformed so that it coincides with a part of the bifurcation set of the standard form. Analysis of this reveals imperfections which decrease the critical load. Algorithms are given to compute these decreases. Finally the different possible forms of the equilibrium paths are sketched.