bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Note on Physical Components
Authors: Williams G. , Hector D. L. 
Published: June 2007

AbstractMany differing definitions of physical components of tensors exist in the literature. Most of these agree when defined relative to orthogonal coordinate systems. The purpose of this paper is to compare existing definitions and to clarify the situation in an oblique coordinate system. The conclusion is reached that any mapping of the tensor into the relevant Rn which is one to one, structure preserving and having physical significance can define physical components.
Circular Crack Problem for Initialy Stressed Neo‐Hookean Solid
Authors: Kurashige M. 
Published: June 2007

AbstractFor an axisymmetric problem under incremental deformation theory for neo‐Hookean solid, a basic equation to be satisfied by a displacement function is obtained and the components of incremental displacement, strain and stress are expressed by the displacement function. Using the basic equation and expressions, the distribution of incremental stress in the neighbourhood of a circular crack with internal pressure in an infinite body under an initial finite deformation owing to all‐around compression is investigated, and the influence of initial stress upon the distribution of incremental stress is presented in the form of curves.
Über die Unstetigkeiten des Interferenzkernes im Integralgleichungssystem für ein in Unterschallströmung harmonisch schwingendes T‐Leitwerk
Authors: Martinez J. 
Published: June 2007

AbstractFür ein in Unterschallströmung harmonisch schwingendes T‐Leitwerk wird der Interferenzkern des Integralgleichungssystems, welches die Amplitudenfunktionen der Anstellwinkel‐ und Druckverteilung zueinander in Beziehung setzt, untersucht. Für den unstetigen Anteil des Interferenzkernes wird ein geschlossener Ausdruck angegeben. Diese Darstellung ist bei der numerischen Bestimmung der Druckverteilung eines harmonisch schwingenden T‐Leitwerkes anwendbar.
Geometrische Bemerkungen zur Theorie nichtstationärer Gasströmungen
Authors: Sauer R. 
Published: June 2007

AbstractBei der nichtstationären eindimensionalen Strömung von Gasen ist bei Beschränkung auf isentropische Zustandsänderungen der Druck p eine Funktion der Zustandsgrößen x1, x2 (x1 = Energie der Masseneinheit = Wärmeinhalt + kinetische Energie, x2 = Strömungsgeschwindigkeit) und die Stromfunktion Ψ eine Funktion von y1, y2 (y1 = Länge, y2 = Zeit). Die Druckfläche p = p (x1, x2) und die Stromfunktionsfläche Ψ = Ψ (y1, y2) sind dabei durch die vorgegebene Strömung in bestimmter Weise aufeinander bezogen. Es wird vorausgesetzt, daß diese Beziehung eine punktweise ein‐eindeutige Abbildung vermittelt. Die geometrischen Eigenschaften dieser Abbildung werden untersucht. Dabei ergeben sich sowohl auf den beiden Flächen als auch in ihren Grundrissen in der x1, x2‐Ebene und der y1, y2‐Ebene bemerkenswerte parallel‐bezogene Paare von Kurvennetzen (anti‐parallele und reziprok‐parallele Kurvennetze).
Lifting‐line Theory of Supercavitating Hydrofoil of Finite Span
Authors: Nishiyama T. 
Published: June 2007

AbstractLifting‐line theory is developed for a supercavitating hydrofoil of finite span at non‐zero cavitation number. Main treatments in the paper are enumerated as follous:

Simplification of basic equations in the perturbed flow field for a supercavitating hydrofoil of large aspect ratio shows that two‐dimensionality still holds with respect to an effective angle of attack over the span.
Making use of this result, an integral equation is derived for the circulation distribution over the span at non‐zero cavitation number and then its numerical method of solution is shown.
Foil characteristics are obtained analytically from circulation calculated and also discussed in details in relation to the aspect ratio and cavitation number. Particularly, a three dimensional correction factor is introduced to the supercavitating hydrofoils of finite span.
Comparisons with the experimental data and former theories are made to confirm the appropriateness of the present theory.
Zur Konstruktion invarianter polyedrischer Kegel für gewisse Klassen von reellen Matrizen und deren Ausnutzung für Fehlerabschätzungen beim Eigenwertproblem
Authors: Schwetlick H. 
Published: June 2007

AbstractEs werden hinreichende Bedingungen dafür angegeben, daß sich eine reelle Matrix mittels einer speziellen Ähnlichkeitstransformation in eine Matrix mit nichtnegativen Elementen überführen läßt. Diese Bedingungen werden verwendet, um mittels der Sätze von Perron und Collatz Fehlerabschätzungen für den betragsgrößten Eigenwert einer Matrix und einen zugehörigen Eigenvektor anzugeben. Dabei muß eine Näherung für diesen Eigenvektor bekannt sein.
Wavemechanics of Compressible Fluids
Authors: Wilhelm H. E. 
Published: June 2007

AbstractIt is shown that the complete set of nonlinear conservation equations for mass, vector momentum, and energy of compressible, dissipation‐free fluids can be transformed into a complex, scalar wave equation. The latter contains only a single nonlinear term which has the meaning of a pressure potential. Thus the transformation leads to a considerable simplification in the mathematical description of compressible fluids. As a concrete illustration of the wavemechanical formulation, the dispersion of acoustic waves is treated briefly.
Linearisierung der instationären, gasdynamischen Gleichung und Diskussion der Voraussetzungen an verschiedenen Fällen
Authors: Sockel H. 
Published: June 2007

AbstractDie vorliegende Linearisierung der gasdynamischen Gleichung ist allgemein gehalten und kann daher auf alle speziellen Fälle angewendet werden. Anhand von Beispielen wird gezeigt, wie man aus den Randbedingungen den für das Einzelproblem charakteristischen Parameter erhält. Dieser erlaubt eine Abschätzung der Größe des instationären Gliedes im Vergleich zu den anderen Ausdrücken in der Differentialgleichung.
Über die Gewinnung von Optimalitätsbedingungen für nichtkonvexe Optimierungsaufgaben durch Lösung linearer Programme
Authors: Kleinmichel H. 
Published: June 2007

AbstractJeder nichtlinearen Optimierungsaufgabe werden zwei lineare Optimierungsaufgaben zugeordnet. Mit den Lösungen der zugeordneten linearen Aufgaben lassen sich einfache Optimalitätsbedingungen für das nichtlineare Ausgangsproblem formulieren.
Zur Konstruktion von Bergman‐Operatoren
Authors: Watzlawek W. 
Published: June 2007

AbstractFür eine bestimmte Klasse linearer partieller Differentialgleichungen zweiter Ordnung wird eine Möglichkeit zur Gewinnung von Bergman‐Operatoren aus gewissen Lösungen der Differentialgleichung angegeben. Für die Spezialfälle der Helmholtzgleichung und einer von K. W. Bauer untersuchten Differentialgleichung ergeben sich von M. Kracht und E. Kreyszig auf andere Weise aus der Riemann‐Funktion erhaltene Operatoren.
Eine allgemeine Aussage über die Stabilität ausgewanderter Schwingungsmittellagen bei determinierter Erschütterung
Authors: Merz E. 
Published: June 2007

AbstractAlle Untersuchungen über das Auswanderungsverhalten von Schwingungsmeßgeräten und elektrischen Zeigermeßwerken bei determinierten Erschütterungen haben stets auf denselben Stabilitätsentscheid geführt. In dieser Arbeit wird der Nachweis erbracht, daß dieser Stabilitätsnachweis für solche Probleme und auch für allgemeinere Bewegungsgleichungen ähnlichen Aufbaus generell gilt. Die umfangreiche Stabilitätsuntersuchung wird damit wesentlich vereinfacht.
On a Class of Steady Nonrotating Axisymmetric Flows: II
Authors: Rassmussen H. 
Published: June 2007

AbstractDie in Teil I (ZAMM 51, (1971)) begonnene Untersuchung derjenigen nichtrotierenden stationären, zähen, inkompressiblen und achsensymmetrischen Strömungen, bei denen die Axialkomponente der Geschwindigkeit nur von dem längs der Achse gemessenen Abstand von einem Bezugspunkt abhängt, wird fortgesetzt. Es werden die restlichen beiden Fälle der integrierten Form der maßgeblichen gewöhnlichen Differentialgleichung betrachtet und ihre Lösungen in einem dreidimensionalen Phasenraum studiert.
Eine Schalentheorie endlicher Verformungen und ihre Anwendung zur Herleitung der Stabilitätstheorie
Authors: Başar Y. 
Published: June 2007

AbstractIn der vorliegenden Arbeit werden zuerst für endliche Verzerrungs‐ bzw. Verschiebungsgrößen die Grundgleichungen elastischer Schalentragwerke hergeleitet. Das Materialgesetz wird in zwei verschiedenen Formen vorausgesetzt, die dann zu entsprechenden Gleichgewichtsbedingungen und konstitutiven Gleichungen führen. Die aufgestellte Theorie stützt sich auf die Annahme der Normalenhypothese. Ausgehend von den allgemeinen Gleichungen der nichtlinearen Theorie werden dann die linearen Stabilitätsbeziehungen abgeleitet. Mit Hilfe dieser Grundgleichungen kann das Differentialgleichungssystem zur Stabilitätsuntersuchung von Schalentragwerken mit beliebiger Geometrie und Belastung in abstrakter Weise aufgestellt werden.
Systeme mit linearem Hauptteil und linearen Abschätzungen für die Störfunktion
Authors: Kappel F. 
Published: June 2007

AbstractIn der vorliegenden Arbeit werden Systeme der Gestalt
magnified image
A eine konstante Matrix, betrachtet. Mit Hilfe der direkten Methode Ljapunovs werden lineare Schranken für die Störfunktion g(x, t) angegeben, wobei als Ljapunov‐Funktionen quadratische Formen verwendet werden. Es wird ein numerisch brauchbares Verfahren angegeben, um möglichst günstige Schranken zu erhalten.
Abbrechkriterium für Iterationsverfahren
Authors: Krawczyk R. 
Published: June 2007

AbstractDie unendliche Folge xn des allgemeinen Iterationsverfahrens zur Lösung einer Operatorgleichung x = T x in einem metrischen Raum wird häufig durch eine endliche Folge x̃n approximiert, welche von der benutzten Rechenanlage abhängt. Es wird ein Abbrechkriterium angegeben, welches die “numerische Konvergenz” im Sinne von [3] garantiert. Dieses Abbrechkriterium wird auf das Newtonsche Verfahren zur Lösung einer Gleichung im Reellen und auf eine lineare Integralgleichung angewandt.
Über reguläre Zerlegungen bei nichtlinearen Abbildungen
Authors: Alefeld G. 
Published: June 2007

AbstractIn [3] hat R. S. Varga den Begriff der regulären Zerlegung einer Matrix eingeführt und damit die Konvergenz einiger Iterationsverfahren zur Auflösung linearer Gleichungssysteme nachgewiesen. In dieser Arbeit sollen diese Ergebnisse in zweierlei Hinsicht verallgemeinert werden: Einerseits werden auch nichtlineare Abbildungen zugelassen, andererseits werden alle Aussagen in einem halbgeordneten Banachraum formuliert und bewiesen. Als konkrete Anwendung ergeben sich unmittelbar Aussagen über die Konvergenz einiger Iterationsverfahren zur Auflösung nichtlinearer Gleichungssysteme im Rn.
Forced Motion of Elastic Cylindrical Rods A Comparison of Two Theories
Authors: Reismann H. , Tsai L.‐W. 
Published: June 2007

AbstractThis investigation considers axial forced motion of elastic rods of finite length, and compares the predictions of elementary red theory (as characterized by the wave equation) with those of an improved theory which accounts for longitudinal as well as radial motions. A specific example of transient forced motion indicates the possibility of considerable differences in the predictions of the two theories.
Effects of Shearing Force and Rotary Inertia to Dynamical Behaviours of Thin Cylindrical Shells Subjected to Impulsive Inner Pressures
Authors: Suzuki S. 
Published: June 2007

AbstractBehaviours of dynamical stresses and bending moments acting in the cantilevered thin cylindrical shells subjected to impulsive inner pressure are investigated. Cylinder is assumed to be elastic and inner pressure to be expressed as step function with respect to time. In this analysis, shearing force and rotatory inertia are taken into consideration. Relationships between dimensions of a cylinder and dynamic load factors with respect to hoop stress at free end and bending moment at clamped end are studied. From the results of analysis, it became evident that the values of dynamic load factors with respect to hoop stress at free end for the case where two factors are taken into consideration are much different from those for the case where these are neglected.
Adaptation of baroreflex function to increased carotid artery stiffening in patients with transposition of great arteries
Authors: Pinter Alexandra , Laszlo Andrea , Mersich Beatrix , Kadar Krisztina , Kollai Mark 
Published: June 2007

We have shown previously that TGA (transposition of great arteries) is associated with increased carotid artery stiffness. It has been established that stiffening of the barosensory vessel wall results in reduced baroreceptor activation and impaired BRS (baroreflex sensitivity). In the present study we tested the hypothesis that the increased carotid artery stiffness in TGA patients was associated with reduced cardiovagal BRS. We studied 32 TGA patients aged 9–19 years, 12±3 years after surgical repair and 32 age-matched healthy control subjects. Carotid artery diastolic diameter and pulsatile distension was determined by echo wall tracking; carotid blood pressure was measured by tonometry. BRS was measured using spontaneous techniques [BRSseq and LFgain (low-frequency transfer function gain)] and by the phenylephrine method (BRSphe). Carotid artery distensibility was markedly reduced in patients as compared with controls (5.6±1.9×10−3 compared with 8.7±2.7×10−3/mmHg P&lt;0.05, as determined using an unpaired Student's t test), but BRS was not different in patients and controls (20.3±14.7 compared with 21.7±12.7 for BRSseq; 13.1±9.2 compared with 10.6±4.5 for LFgain; and 19.1±8.6 compared with 24.8±7.2 for BRSphe respectively). Carotid artery elastic function was markedly impaired in patients with TGA, but the increased stiffness of the barosensory vessel wall was not associated with reduced BRS. It appears that attenuation of baroreceptor stimulus due to arterial stiffening may be compensated by other, possibly neural, mechanisms when it exists as a congenital abnormality.
Evaluation of ischaemia-modified albumin as a marker of myocardial ischaemia in end-stage renal disease
Authors: Sharma Rajan , Gaze David C. , Pellerin Denis , Mehta Rajnikant L. , Gregson Helen , Streather Christopher P. , Collinson Paul O. , Brecker Stephen J. D. 
Published: June 2007

The early diagnosis of myocardial ischaemia is problematic in patients with ESRD (end-stage renal disease). The aim of the present study was to determine whether IMA (ischaemia-modified albumin) increases during dobutamine stress and detects myocardial ischaemia in patients with ESRD. A total of 114 renal transplant candidates were studied prospectively, and all received DSE (dobutamine stress echocardiography). IMA levels were taken at baseline and 1 h after cessation of DSE. A total of 35 patients (31%) had a positive DSE result. Baseline IMA levels were not significantly different in the DSE-positive and -negative groups. The increase in IMA was significantly higher in the DSE-positive group compared with those with no ischaemic response (26.5±19.1 compared with 8.2±9.6 kU/l respectively; P=0.007; where kU is kilo-units). From ROC (receiver operator charactertistic) curve analysis, the optimal IMA increase to predict an ischaemic response was 20 kU/l, with a sensitivity of 81% and a specificity of 72% [area under the curve, 0.80 (95% confidence interval, 0.44–0.94); P=0.03]. There were 18 deaths, ten of which were cardiac in nature over a follow up period of 2.25±0.71 years. An increase in IMA ≥20 kU/l was associated with significantly worse survival (P=0.02). In conclusion, IMA is a moderately accurate marker of myocardial ischaemia in ESRD. Patients with an increase in IMA ≥20 kU/l during DSE had significantly worse survival.
Inoculation and Passaging of Mammalian Cell Suspension Cultures
Authors: Darlington Gretchen J. 
Published: June 2007

INTRODUCTIONThis protocol describes the growth and passaging of mammalian cells in suspension culture using a simple dilution procedure. In situations in which total replacement of medium is desired, the cells can be gently pelleted by centrifugation and resuspended in the appropriate medium.
Xenopus laevis Animal Cap/Vegetal Endoderm Conjugates: Figure 1.
Authors: Sive Hazel L. , Grainger Robert M. , Harland Richard M. 
Published: June 2007

INTRODUCTIONIn Xenopus laevis, mesoderm can be induced in animal cap cells by contact with vegetal cells (presumptive endoderm). This juxtaposition of tissues was the first indication that the process of mesoderm induction could be separated from neural induction. This protocol describes how to set up a conjugate using Xenopus animal cap and vegetal tissue. In theory, a single embryo can provide both animal and vegetal cells; however, in practice, this is difficult to achieve.
Xenopus laevis Animal Cap/Dorsal Mesoderm Conjugates: Figure 1.
Authors: Sive Hazel L. , Grainger Robert M. , Harland Richard M. 
Published: June 2007

INTRODUCTIONIn Xenopus laevis, dorsal mesoderm is also called “organizer” tissue or Spemann’s organizer. It is fated to form the prechordal plate and notochord, as well as some somitic tissue. This protocol presents a method for the preparation of dorsal mesoderm conjugates, which can be useful in assessing whether test genes or promoters are responsive to dorsal mesodermal signals and, if so, by what region of the mesoderm they are induced. The example presented here is an animal cap/dorsal mesoderm conjugate.
An Expedient and Versatile Protocol for Extracting High-Quality DNA from Plant Leaves
Authors: Vallejos C. Eduardo 
Published: June 2007

INTRODUCTIONProtocols for extracting plant genomic DNA have to contend with two major challenges: preventing the oxidation of phenolic substances that can react with nucleic acids and proteins, and eliminating polysaccharides that interfere with downstream enzymatic manipulations of DNA. A protocol has been developed in which the above-mentioned substances are removed from the sample before the DNA is removed from the chromatin structure. This protocol requires only two tubes during extraction and a single precipitation step to yield high-quality DNA. DNA extracted with this method has virtually no protein or phenolic contaminants (A260/A280>1.8), is RNA-free, contains high-molecular-weight fragments according to CHEF electrophoresis, and is fully digestible by restriction enzymes. This protocol has been successfully tested with leaf samples from common bean and corn; with leaves known to be rich in phenolics (tomato and bell pepper), pectins (sweet orange, grapefruit, and peach), or both substances (Muscadine grape); and with leaves that contain latex in the sap (papaya).
PCR-Based Analysis of Immunoprecipitated Chromatin: Figure 1.
Authors: Wagschal Alexandre , Delaval Katia , Pannetier Maëlle , Arnaud Philippe , Feil Robert 
Published: June 2007

INTRODUCTIONAfter chromatin immunoprecipitation (ChIP), different PCR-based approaches can be used to determine how much DNA is precipitated at a locus of interest. Real-time PCR amplification is often the preferred technique. One can also use duplex PCR amplification, which is the coamplification of a fragment from the region of interest and a control fragment (e.g., the actin gene, or the tubulin gene). This approach allows for estimating relative levels of specific histone modifications along chromosomal domains. For allele-specific studies (for instance, on dosage-compensation mechanisms or on genomic imprinting), electrophoretic detection of single-strand conformation polymorphisms (SSCP) or similar strategies such as hot-stop PCR can differentiate PCR products that represent the silent allele from those amplified from the active allele. If a polymorphic restriction site is present in one allele and absent in the other, the method of choice is hot-stop PCR. If no polymorphic restriction sites are available, but there are single nucleotide polymorphisms (SNPs) that distinguish the alleles of interest, the best approach is to separate the PCR products derived from the two different alleles using SSCP. In SSCP, it is possible to discriminate denatured PCR products derived from one allele or the other because the secondary structure of each single strand will be directly dependent on the sequence itself. Hence, in nondenaturing gel conditions, each single strand will migrate differently. These four PCR-based methodologies to analyze immunoprecipitated chromatin (real-time PCR, duplex PCR, hot-stop PCR, and SSCP) are presented here.
Viability Staining of Mammalian Cell Cultures
Authors: Darlington Gretchen J. 
Published: June 2007

INTRODUCTIONVarious manipulations of cells, including passaging, freezing, and dissociation from primary tissue, can result in cell death. To determine the number of surviving cells in a population, exclusion of the dye trypan blue can be used. Normal healthy cells are able to exclude the dye, but trypan blue will diffuse into cells in which membrane integrity has been lost. This dye-exclusion method provides a rough estimate of cell viability and often does not distinguish within a 10%-20% difference. Additionally, cells that exclude dye are not necessarily capable of attachment and prolonged survival or proliferation.
Microdissection: Explant and Transplant Assays in Xenopus laevis
Authors: Sive Hazel L. , Grainger Robert M. , Harland Richard M. 
Published: June 2007

INTRODUCTIONWhen analyzing any developmental process, important questions are those relating to the formation of different cell types. What makes a cell decide to become a particular cell type? What cell interactions are involved in this decision? The “commitment” of cells to a particular lineage is also called “specification” or “determination.” Analysis of the cell interactions, or inductions, required for tissue-type determination is a critical step in the identification of the genes that control the process. Lineage commitment and inductive interactions can be assessed by explant or transplant assays with embryos from Xenopus laevis.
Localization of Members of the γ-Glutamyl Transpeptidase Family Identifies Sites of Glutathione and Glutathione S-Conjugate Hydrolysis
Authors: Martin Melinda N. , Saladores Pilar H. , Lambert Elton , Hudson Andre O. , Leustek Thomas 
Published: June 2007

Abstract
γ-Glutamyl transpeptidases (GGTs) are essential for hydrolysis of the tripeptide glutathione (γ-glutamate-cysteine-glycine) and glutathione S-conjugates since they are the only enzymes known to cleave the amide bond linking the γ-carboxylate of glutamate to cysteine. In Arabidopsis thaliana, four GGT genes have been identified based on homology with animal GGTs. They are designated GGT1 (At4g39640), GGT2 (At4g39650), GGT3 (At1g69820), and GGT4 (At4g29210). By analyzing the expression of each GGT in plants containing GGT:β-glucuronidase fusions, the temporal and spatial pattern of degradation of glutathione and its metabolites was established, revealing appreciable overlap among GGTs. GGT2 exhibited narrow temporal and spatial expression primarily in immature trichomes, developing seeds, and pollen. GGT1 and GGT3 were coexpressed in most organs/tissues. Their expression was highest at sites of rapid growth including the rosette apex, floral stem apex, and seeds and might pinpoint locations where glutathione is delivered to sink tissues to supplement high demand for cysteine. In mature tissues, they were expressed only in vascular tissue. Knockout mutants of GGT2 and GGT4 showed no phenotype. The rosettes of GGT1 knockouts showed premature senescence after flowering. Knockouts of GGT3 showed reduced number of siliques and reduced seed yield. Knockouts were used to localize and assign catalytic activity to each GGT. In the standard GGT assay with γ-glutamyl p-nitroanilide as substrate, GGT1 accounted for 80% to 99% of the activity in all tissues except seeds where GGT2 was 50% of the activity. Protoplasting experiments indicated that both GGT1 and GGT2 are localized extracellularly but have different physical or chemical associations.