bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intermittent parathyroid hormone (PTH) treatment and age‐dependent effects on rat cancellous bone and mineral metabolism
Authors: Friedl Gerald , Turner Russell T. , Evans Glenda L. , Dobnig Harald 
Published: June 2007

AbstractIn recent years, intermittent PTH treatment has been investigated extensively for its efficacy in preventing osteoporotic fractures and to improve fracture healing and implant fixation. Although these tasks concern patients of all ages, very little is known about whether aging impacts the bone anabolic response to PTH. Female Sprague‐Dawley rats of 1, 3, and 13 months of age were either treated by hPTH‐(1‐34) or by vehicle solution (CTR) for 1 week. As main outcome measures, we determined the effects on static and dynamic histomorphometry of cancellous bone. In addition, we measured gene expression in femur and serum parameters reflecting bone turnover and mineral metabolism. There was a profound decrease in bone formation rate (BFR) with aging in CTR rats, whereas PTH treatment resulted in a significant relative 1.5‐, 3‐, and 4.7‐fold increase in BFR, without altering indices of bone resorption. Aging decreased and PTH increased mRNA levels for bone matrix proteins and growth factors in a gene‐specific manner. In younger animals, PTH‐induced a marked stimulation in the mineral apposition rate with no effect on osteoblast number, whereas the latter was increased in older animals (1.0‐, 1.7‐, and 3.1‐fold). Treatment with PTH in young rats led to a significant increase in trabecular number (1.6–2.6/mm, p < 0.05), whereas older rats demonstrated increases in trabecular thickness only (52.8–77.8 µm, p < 0.001). Although PTH increased bone formation at all ages, we found significant age‐related differences in the cellular and molecular mechanisms involved in the bone anabolic response to the hormone. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1454–1464, 2007
Laboratory preparation and evaluation of Pollock variety avocado (Persea americana Mill) guacamole
Authors: Ramtahal Giselle A , Akingbala John O , Baccus‐Taylor Gail SH 
Published: June 2007

AbstractGuacamole was produced from ripe avocado (Persea americana) by blending the pulp with local herbs, spices and salt. The guacamole was stored at 5 °C for 2 weeks, during which physical, chemical and microbial analyses were conducted. Organoleptic evaluations by a semi‐trained panel were also performed, until the guacamole was deemed unfit for human consumption. The results indicated that fresh avocado pulp contains 835, 13, 16, 92, 44, 16 and 0.078 g kg−1, moisture, ash, protein, fat, carbohydrate, fiber, and vitamin C respectively, and has a pH of 6.7; compared with 838, 13, 16, 92, 44, 16, and 0.042 g kg−1, respectively, of the same nutrients in freshly prepared guacamole, which has a pH of 6.0. During storage, the moisture content, consistency, total soluble solids and total titratable acidity (as citric acid) of the guacamole increased, but the vitamin C content decreased. The color of the avocado pulp, which darkened during conversion into guacamole, darkened further as storage increased as evidenced by a decrease in the L, a and b values. Sensory evaluation revealed that the mean storage period (5 °C) for the guacamole was 6 days. Although the fresh avocado pulp, the freshly prepared guacamole, and the stored guacamole contained bacteria, yeasts and molds, the pathogens Staphylococcus aureus and Salmonella were absent. Copyright © 2007 Society of Chemical Industry
THE FATE OF THE FIVE‐CENT‐FARE. II THE NEW TRAMWAYS CONTRACT IN MONTREAL
Authors: Wilcox Delos F. 
Published: June 2007

AbstractThe first article under this title appeared in the November issue and others will follow every month hereafter, covering the situation in various American cities. Montreal's solution, calling for service‐at‐cost plus a bonus for good service, is novel and ingenious though legally hampered.
A computational strategy for poroelastic problems with a time interface between coupled physics
Authors: Néron D. , Dureisseix D. 
Published: June 2007

AbstractThis paper deals with a computational strategy suitable for the simulation of multiphysics problems and based on the LArge Time INcrement (LATIN) method. One of the main issues in the design of advanced tools for the simulation of such problems is to take into account the different time and space scales that usually arise with the different physics. Here, we focus on using different time discretizations for each physics by introducing an interface with its own discretization. The proposed application concerns the simulation of a 2‐physics problem: the fluid–structure interaction in porous media. Copyright © 2007 John Wiley & Sons, Ltd.
Digital cementum luminance analysis (DCLA): a tool for the analysis of climatic and seasonal signals in dental cementum
Authors: Wall‐Scheffler C. M. , Foley R. A. 
Published: June 2007

AbstractCementum banding patterns have been used by archaeozoologists and wildlife managers for a number of decades to assess the season and age at death of mammalian populations. However, the observation and measurement of the nature of cementum banding, especially that of the final band, has proved to be difficult except under conditions of excellent preservation and advanced microscopy. The research presented here details a method for extracting luminance data from the banding patterns of cementum in order to quantify the optical properties of cementum tissue. By doing so, analysis of the relationship between cementum deposition and environmental variables is achieved. We present the results of a digital cementum luminance analysis (DCLA) on a sample of first molars from two species,Ovis aries, Soay andCapra ibex. The results indicate that significant relationships occur between seasonal temperature changes and cementum histology. Furthermore, we show that luminance values can be used to assess the geographical range of genetically similar populations. Our results demonstrate that the study of luminance is a vital tool for the quantitative study of dental cementum for both archaeological and ecological studies. Copyright © 2007 John Wiley & Sons, Ltd.
Time‐course of change in [11C]carfentanil and [11C]raclopride binding potential after a nonpharmacological challenge
Authors: Scott David J. , Stohler Christian S. , Koeppe Robert A. , Zubieta Jon‐Kar 
Published: June 2007

AbstractPositron Emission Tomography (PET) with appropriate radiotracers and quantification methods allows the detection of changes in endogenous neurotransmission by determine the reduction in the binding potential (BP) of receptors before and after experimental challenges. These have typically employed psychostimulants and PET with dopamine (DA) receptor radiotracers. However, reductions in BP persist far beyond the increases in the release of the endogenous neurotransmitter, an effect ascribed to receptor internalization and recycling, a possible confound in repeated studies. Here we examined the time‐course of changes in BP during a nonpharmacological challenge, moderate levels of sustained pain, shown to induce robust reductions in μ‐opioid and DA D2 BP, as measured with [11C]carfentanil and [11C]raclopride. It was hypothesized that, contrary to pharmacological probes, the use of a more “physiological” stimulus would not be associated with persistent changes in the BP measures. The pain challenge was associated with reductions in μ‐opioid receptor BP in several cortical and subcortical regions. These did not persist in a subsequent scan. Similar results were obtained for DA D2 receptor BP, where the pain challenge induced significant reductions in the caudate nucleus. These data demonstrate that changes in receptor BP induced by a nonpharmacological challenge did not persist into subsequent scans. They further suggest differences in the effect of pharmacological and nonpharmacological probes on PET BP measures. These may reflect varying levels of change in receptor affinity, receptor internalization, and recycling depending on the type of challenge employed. Synapse 61:707–714, 2007. © 2007 Wiley‐Liss, Inc.
A small dopamine permeability of storage vesicle membranes and end product inhibition of tyrosine hydroxylase are sufficient to explain changes occurring in dopamine synthesis and storage after inhibition of neuron firing
Authors: Wallace Lane J. 
Published: June 2007

AbstractComputer simulations of dopamine (DA) regulation at a striatal varicosity were developed to determine basic principles that explain the pattern of changes in level of neurotransmitter and its rate of synthesis and metabolism when DA neuron firing is inhibited. The models suggest that DA synthesis is normally at a slower rate because of end‐product inhibition of tyrosine hydroxylase (TH) by cytosolic DA. The vast majority of DA in the cytosol arrives there via “recycling”—DA that was released during an exocytotic event is moved into the cytosol via the dopamine transporter (DAT). When neuronal firing is inhibited, the amount of cytosolic DA markedly decreases as there is no recycling. The rate of DA synthesis then increases because of the loss of end‐product inhibition of TH. The newly synthesized DA is stored in vesicles, thus increasing the total amount of DA in the vesicles. A small amount of DA is continually leaking out of vesicles, and the amount leaking out increases proportionally to the amount of DA in vesicles. When the amount of DA leaking out balances the amount being stored by the vesicular monoamine transporter, DA accumulates in the cytosol. The accumulating DA inhibits TH activity, and the system enters a steady state condition characterized by approximately double the normal amount of DA in vesicles and approximately normal rate of DA synthesis and metabolism. Synapse 61:715–723, 2007. © 2007 Wiley‐Liss, Inc.
Free Convection in a Trench with Radiative Wall Conditions
Authors: De Socio L. M. , Misici L. 
Published: June 2007

AbstractFree convection is considered in a rectangular trench with an assigned temperature distribution at the bottom and radiative vertical walls. Following a domain perturbation technique, the problem reduces to the Stokes' equation. After proving the existence and uniqueness of the solution, from a functional point of view, the stream function is expressed in closed form via a bi‐harmonic series and the shape of the free surface is also given. An application follows in order to show the convergence characteristics of the solution and the flow structure.
Dynamic Behavior of Distensible Fluid Lines Carrying a Pulsating Incompressible Liquid
Authors: Bauer H. F. , Metten St. , Siekmann J. 
Published: June 2007

AbstractAn analysis of the propagation of pressure waves through a thin‐walled elastic tube, filled with a streaming incompressible fluid, is presented. The outer surface of the tube is assumed to be free. Axially symmetric solutions for the linearized equations governing the motion of the (viscous or nonviscous) fluid and the (elastic) solid are obtained. The motion of the tube wall is described by the Donnell shell equations. The solutions lead to a complicated transcendental dispersion equation relating wave number and frequency. This equation is studied by both analytical and numerical means in some detail.
Schwingungen unter gleichzeitiger zufälliger Zwangs‐ und Parametererregung
Authors: Schmidt G. 
Published: June 2007

AbstractSchwingungen eines Systems mit einem Freiheitsgrad, kombinierter zufälliger Zwangs‐ und Parametererregung in Form eines Weißen Rauschens und Rückstell‐, Trägheits‐ und Dämpfungsnichtlinearitäten werden untersucht. Mit Hilfe der Theorie der Itǒgleichungen und einer iterativen Methode von Stratonovich, die die Methode der stochastischen Mittelung verallgemeinert, werden stationäre Lösungen der Fokker‐Planck‐Kolmogorov‐Gleichung für die Verteilungsdichte der Amplitude gefunden, die zu Ergebnissen über verschiedene Momente und die Wahrscheinlichkeit für das Überschreiten eines festen Amplitudenniveaus führen.
Ecoulement moléculaire libre autour d'un dièdre droit
Authors: Tiem Dang Hong 
Published: June 2007

AbstractDie freie Molekularströmung an einem konkaven rechtwinkligen Keil wird systematisch untersucht. Die ungestörte Gasströmung wird maxwellisch und die Reflektion an der Grenzfläche wird als vollkommen diffus vorausgesetzt. Es werden analytische Ausdrücke für die makroskopischen Größen der Gasströmung erhalten und die nummerischen Ergebnisse werden in Form von Linien gleicher Dichte, gleicher Temperatur und von Stromlinien wiedergegeben.
Der Einfluß der Verformungen des Grundzustandes auf die Stabilität gerader Stäbe
Authors: Heinen A. , Eilering S. 
Published: June 2007

AbstractIn [7] wurde eine allgemein gültige Stabilitätstheorie für gerade, elastische Stäbe hergeleitet, mit der jeder beliebige (auch nichtlineare) Grundzustand auf seine Stabilität hin untersucht werden kann. In dieser Arbeit werden die in [7] angegebenen Stabilitätsgleichungen für ein Kipp‐ und ein Torsionsproblem exakt gelöst. Dabei wird in exemplarischer Weise der oft erhebliche Einfluß der Verformungen des Grundzustandes aufgezeigt.
On Numerical Solution Scheme for Thermoelastic Problems in Inhomogeneous Media by means of Boundary‐Volume Element
Authors: Tanaka Masataka , Tanaka Kikuaki 
Published: June 2007

AbstractThe paper is concerned with thermoelastic problems in which the material constants are prescribed as arbitrary, continuous and differentiable functions of spatial coordinates. The formulation is made in terms of Green's function which is available in the literature for homogeneous elastostatics. The governing equation is transformed into a set of integral equations in the inner domain and also on the boundary. The resulting integral equations are discretized by means of boundary elements as well as volume elements. The behavior of the problems is completely determined by solving simultaneously the system of linear equations thus obtained.
Untersuchung von Parameternichtlinearitäten bei Übersetzungsgetrieben
Authors: Hortel M. , Schmidt G. 
Published: June 2007

AbstractAn Hand eines elastisch gelagerten Zahnradübersetzungsgetriebes wird der Einfluß der nichtlinearen, mit der Zeit veränderlichen Steifigkeitsglieder, der sogenannten Parameternichtlinearität, untersucht. Die mit Hilfe der Integralgleichungsmethode durchgeführte Analyse des Hauptresonanzfalles zeigt insbesondere den beachtlichen qualitativen Einfluß der Parameternichtlinearität. Diese Eigenschaften können nicht nur beim Konstruktionsentwurf, sondern auch in manchen Fällen an fertigen Konstruktionen zu schwingungsverkleinernden Änderungen ausgenützt werden.
Angenäherte Fehlerermittlung Für Modalsynthese‐Ergebnisse innerhalb der Systemanalyse und Systemidentifikation
Authors: Natke H. G. 
Published: June 2007

AbstractDie Modalsynthese ist ein Verfahren zur Untersuchung des dynamischen Verhaltens komplizierter schwingungsfähiger elastomechanischer Systeme mittels Subsystem‐Ergebnissen. In der vorliegenden Arbeit ist Für endlichdimensionale Systeme ein. Verfahren zur angenäherten Fehlerermittlung der Modalsyntheseergebnisse mitgeteilt, das auf der dynamischen Kondensation beruht und die Kenntnis der Modalgrößen der unterdrückten Freiheitsgrade nicht benötigt. Das Vorgehen ist bei jeder regulären Transformation in generalisierte Koordinaten anwendbar. Beispiele zeigen Für eine ungünstige Transformation die Güte der angenäherten Fehler.
The General Theory of the Motion of a Single Wheelset Moving through a Curve with Constant Radius and Cant
Authors: de Pater A. D. 
Published: June 2007

AbstractPaper deals with the problem of the motion of a railway wheelset through a curve with constant radius and cant. The investigation includes both the stationary and the parasitic movement. General equations of motion are derived; both as Lagrange's equations and as the equations expressing the rate of change of the momentum and of the moment of momentum of the wheelset. For values of the curve radius which tend to infinity, the equations of motion can be considered as exact‐ones. The equations are very complicated and before solving them they should be reduced by taking into account that the wheelset and contact point displacements always remain small as compared with the track gauge, whereas the rotation angles (of the parasitic motion) of the wheelset remain small with respect to unity. The draft of such a first‐order theory will be the subject of a forthcoming publication.
Hydromagnetic Flow in Thin Films of Liquid with a Rheological Power‐Law
Authors: Roy S. K. , Agarwal J. P. 
Published: June 2007

AbstractThe problem of determining the flow characteristics of a thin film of conducting non‐Newtonian power‐law liquid adhering to a vertical plate in the presence of a magnetic field has been investigated for two cases, namely, the plate stationary and the plate withdrawn with a constant velocity from a liquid bath. It is found that the effect of increase in magnetic field is to decrease the velocity in the case of stationary plate and to increase the velocity in the case of moving plate. The flow rate of the film, however, decreases with increase in the magnetic field in both the cases, and the flow of the film is thereby restricted. Moreover, when a dilatant liquid film flows along a stationary plate, there is found to exist a critical value of the generalized Hartmann number, and if the generalized Hartmann number exceeds its critical value, there appears a zone near the free surface in which the liquid flows like a quasi‐solid body. This zone widens with the increase in the generalized Hartmann number.
Behaviour of Finite Amplitude Waves in a Radiating Gas
Authors: Sharma V. D. , Shyam Radhe , Menon V. V. 
Published: June 2007

AbstractA differential approximation for the equations of radiative transfer in a grey gas of arbitrary opacity including the effects of radiative flux, pressure and energy density is applied in a study of the effects of thermal radiation on the growth and decay properties of finite amplitude waves of arbitrary shape propagating through a thermally inviscid gas.
On Some Generalized Free Boundary‐Value Problem for a System of One‐Dimensional Diffusion Equations
Authors: Wolska‐Bocheneky J. , v. Wolfersdorf L. 
Published: June 2007

AbstractA free boundary value problem for a system of two one‐dimensional diffusion equations occurring in metal physics is dealt with by reducing to a system of two nonlinear integral equations of Volterra type following a known method due to A. Friedman.
Sturm‐Sequence Check for Eigenproblems Resulting from Variational Principles with Subsidiary Conditions
Authors: Mang H. A. , Walter H. 
Published: June 2007

AbstractPermitting determination of the number of eigenvalues smaller than a shift to the right of the largest one of these eigenvalues, the well‐known “Sturm‐sequence check” is an indispensable remedy for the numerical solution of large‐scale eigenproblems. The purpose of the present paper is to adapt the classical “Sturm‐sequence check” for application to eigenproblems derived from variational principles with subsidiary conditions in the form of linear constraint conditions for the unknowns, as are frequently occurring in technical applications. The scope of this article encompasses theoretical considerations as well as a numerical study. The objectives of the numerical investigation are twofold: (a) numerical verification of the theoretical findings by means of transparent hand‐calculation and (b) application of a computer algorithm containing the modified “Sturm‐sequence check”.
Transverse Curvature Effects on a Slender Cone with Heat Transfer and Angle of Attack
Authors: Kumar Pradeep , Jain A. C. 
Published: June 2007

AbstractFür das dreidimensionale Grenzschichtproblem werden die Gleichungen in räumlichen Polarkoordinaten für eine kompressible Strömung an einem schlanken Kegel mit Wärmeübertragung und Angriffswinkel gelöst. Die Strömungsfunktionen werden in aufsteigende Potenzen der Parameter bezüglich der transversen Krümmung und des Angriffswinkels entwickelt. Die Gleichungen, die bis zur ersten Ordnung der bestimmenden Parameter korrekt sind, werden mit der Methode der Universellen Funktionen gelöst. Man erhält allgemeine Ausdrücke für die Wärmeübertragung und die Koeffizienten der Grenzschicht in der Längs‐ und Umfangsrichtung für die Prandtlzahlen 1,0 und 0,72. Für die Prandtl‐Zahl 1.0 erhält man die Spezialfälle von Probstein und Elliot [1] und Moore [2]. Es wird gezeigt, daß bei Berücksichtigung der Effekte der transversalen Krümmung und des Angriffswinkels die Reynoldssche Analogie zur Berechnung der Wärmeübertragungskoeffizienten nicht gilt. Die für die Prandtl‐Zahl 0,72 vorausberechneten Werte der Wärmeübertragung werden mit experimentellen Daten von Tracy [3] verglichen. Man stellt fest, daß unter Einbeziehung der Effekte der transversalen Krümmung die vorausberechneten Ergebnisse näher bei den experimentellen Daten liegen.
Zur numerischen Berechnung der stationären turbulenten Blasenströmung in senkrechten Kanälen
Authors: Bauerfeind K. 
Published: June 2007

AbstractFür den Fall der ebenen turbulenten Blasenströmung zwischen parallelen Wänden werden die zeitlich1gemittelten Grundgleichungen des Zwei‐Fluid‐Modells unter Verwendung empirischer Ansätze für die Turbulenz‐ und Phasenwechselwirkungs‐Terme mit einem Finite‐Differenzen‐Verfahren gelöst. Konvergenz und Stabilität des Verfahrens werden anhand berechneter Profilentwicklungen wichtiger Strömungsparameter nachgewiesen.
Restoration of reproductive potential after expiration or removal of melengestrol acetate contraceptive implants in Tigers (Panthera tigris)
Authors: Chuei Jason Y. , Asa Cheryl S. , Hall‐Woods Monica , Ballou Jonathon , Traylor‐Holzer Kathy 
Published: June 2007

AbstractThe need for contraception in the successful management of captive wild animals is becoming increasingly apparent. Because concerns exist regarding the reversibility of the contraceptive implant melengestrol acetate (MGA), reproductive data for 94 female Amur (Panthera tigris altaica) and Sumatran tigers (Panthera tigris sumatrae) were analyzed using survival analyses to evaluate return to reproductive status after implant removal or assumed expiration. Females placed in potential breeding situations after MGA implants were surgically removed showed a 62% return to reproduction by 5.25 years, whereas females with implants that were assumed to have expired showed only a 30% return to reproduction by 6 years. Implanted females did not reproduce as successfully as non‐implanted control females, which showed an 85% probability of reproducing after placement in a new breeding situation by 2.66 years. Parturition increased the probability of reproducing in non‐implanted females, but not in implanted females. Litter size, stillbirths, and offspring survival were not significantly different between non‐implanted, implant‐removed and implant‐expired female tigers. Ten female tigers reproduced both before and after implant placement, and the differences in litter size, stillbirths, and offspring survival were not significant, nor were they significantly different from non‐implanted females. Prior parturition, age when implant was removed, and duration of implantation did not affect the probability of reproducing for females after implant removal. These results show substantial reversibility of MGA implants, leading to 62% successful reproduction after implant removal. The reasons for lower successful reproduction in animals previously treated with the contraceptive compared to non‐implanted females are not known, but a greater delay in reversibility was seen when implants were left in place and only presumed expired. Zoo Biol 26:275–288, 2007. © 2007 Wiley‐Liss, Inc.