bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Extremum Principles for Mixed Boundary Value Problems in Magnetohydrodynamic Pipe Flow
Authors: Smith P. 
Published: May 2007

AbstractSome extremum principles are established for the rectilinear flow of a fluid in a pipe under the influence of a uniform magnetic field. The pipe walls are composed of non‐conducting and conducting segments. Bounds are deduced for the mass‐flow rate which can be used to construct asymptotic formulae valid for large Hartmann numbers. Several illustrative examples are included.
A Theoretical Investigation of Finite Amplitude Thermal Convection in Non‐Newtonian Fluids
Authors: van der Borght R. , Murphy J. O. , Steiner J. M. 
Published: May 2007

AbstractFür den Fall sechseckigen Umrisses einer Konvektionszelle endlicher Länge werden die Grundgleichungen hergeleitet, die die Wärmekonvektion in einer nichtnewtonschen Flüssigkeit beschreiben. Ihre numerische Lösung zeigt im Falle zweier freier Ränder, daß die viskoelastischen Effekte die Nusselt‐Zahl nur wenig ändern. Immerhin ist die Nusselt‐Zahl bei gegebener Rayleigh‐Zahl durchweg — wenn auch nur wenig — größer als bei einer newtonschen Flüssigkeit vergleichbarer Viskosität. Diese theoretischen Voraussagen stehen im Einklang mit neueren experimentellen Ergebnissen im Falle zweier starrer Ränder.
Transient Stresses in an Elastic Half Space Resulting from the Frictionless Indentation of a Rigid Wedge‐Shaped Die
Authors: Robinson A. R. , Thompson J. C. 
Published: May 2007

AbstractFür das im Titel genannte Problem erhält man eine im Rahmen der klassischen Elastizitätstheorie exakte Lösung, wenn man annimmt, daß der Halbraum homogen und isotrop ist und der Keil mit konstanter Geschwindigkeit eindringt. Für eine gegebene Form des Keiles und des elastischen Mediums bestimmt die Eindringgeschwindigkeit eindeutig die Geschwindigkeit der vom Rande weg sich ausdehnenden Kontaktzone. Diese Geschwindigkeit, verglichen mit den Geschwindigkeiten der Dilatorischen, Rotatorischen und der Oberflächenwellen im elastischen Medium legt fest, welcher der vier möglichen charakteristischen Übergangszustände der Spannungen sich entwickelt.Jeder der vier Kontaktgeschwindigkeitsbereiche wird mit der Methode der selbst‐ähnlichen Potentiale behandelt.
The Development of Jet Mixing Toward the Asymptotic Similar Solution
Authors: Brink D. F. , Chow W. L. 
Published: May 2007

AbstractIn der Arbeit wird analytisch untersucht, wie sich ein ursprünglich nichtähnliches Geschwindigkeitsprofil bei einem Strahlmischvorgang nach der am Ende asymptotischen ähnlichen Lösung hin entwickelt. Die entsprechenden Gleichungen für die inkompressible Grenzschicht werden mit Hilfe der asymptotischen Integrationsmethode von Meksyn für beide Ströme unterhalb und oberhalb der vorkommenden Stromlinie gelöst. Es wird genau beschrieben und diskutiert, wie sich diese Entwicklung der Strömung zu der schließlichen ähnlichen Lösung unter dem Einfluß der Anfangsbedingung verhält.
Die Beeinflussung der Stabilität von Laminarströmungen durch die Eigenschaften der Wände
Authors: Brechling J. 
Published: May 2007

AbstractDie Entwicklung von Störbewegungen in einer Laminarströmung kann durch Bewegung der die Strömung begrenzenden Wände weitgehend variiert werden. Im einzelnen untersucht wird das Problem der passiven Beeinflussung, bei der die Wandbewegung durch die Störströmung selbst angeregt wird. Zur Berechnung der Stabilität wird ein geeignetes Rechenverfahren zur Integration der Sommerfeldschen Gleichung als Eigenwertaufgabe entwickelt.
Zur Begründung einiger Iterationsmethoden in der Nichtlinearen Kriechtheorie
Authors: Babadshanjan H. 
Published: May 2007

AbstractAm Beispiel von Randwertaufgaben der nichtlinearen Kriechtheorie werden die Methode der zusätzlichen Deformationen und die Methode der zusätzlichen Belastungen begründet.
Über die Konstruktion Greenscher Tensoren und ihre Bedeutung für die numerische Mathematik
Authors: Beckert Herbert 
Published: May 2007

AbstractIn dieser Arbeit wurden zu allgemeinen linearen Bandwertproblemen stark elliptischer Systeme die klassischen und erweiterten Greenschen Tensoren mit Variationsmethoden konstruiert und deren Singularitätsordnung am Rande abgeschätzt. Dieselbe Konstruktion ergeben die reduzierten Greenschen Tensoren über endlichdimensionalen Ritzschen Teilräumen 𝔐n. Für die numerische Mathematik ist von Bedeutung, daß für diese Tensoren auch die klassische Darstellungsformel für die Ritz‐Lösung über 𝔐n gültig ist.
Uric acid changes in urine and plasma: An effective tool in screening for purine inborn errors of metabolism and other pathological conditions
Authors: Simoni R. E. , Ferreira Gomes L. N. L. , Scalco F. B. , Oliveira C. P. H. , Aquino Neto F. R. , Costa de Oliveira M. L. 
Published: May 2007

SummaryPurine inborn errors of metabolism (IEM) are serious hereditary disorders, which should be suspected in any case of neonatal fitting, failure to thrive, recurrent infections, neurological deficit, renal disease, self‐mutilation and other manifestations. Investigation usually starts with uric acid (UA) determination in urine and plasma. UA, the final product of purine metabolism in humans, may be altered not only in purine IEM, but also in other related pathologies and clinical conditions. However, data and information about abnormal UA levels are scattered in the literature, often being controversial and confusing. A comprehensive overview has been elaborated, according to abnormal UA levels in urine and plasma, which associates these alterations with purine IEM. Other possible diseases, clinical conditions, diet and drug intake, related to the metabolism of uric acid, are also presented. The article includes tables that classify the disorders according to different patterns of UA alterations, with pertinent enzymes, clinical symptoms, inheritance and comments. Additionally, summarized pathophysiological mechanisms of important disorders are described. The overview is intended to assist in the interpretation of the results of UA analyses. It demonstrates that variation of UA concentrations in urine and plasma may constitute an effective tool in screening for purine IEM and other related pathological conditions.
Erblicher Brust- und Eierstockkrebs
Authors: Gadzicki D. , Meindl A. , Schlegelberger B. 
Published: May 2007

Zusammenfassung
Erbliche Faktoren spielen eine wesentliche Rolle bei der Entstehung des Brustkrebses. Etwa die Hälfte der erblich bedingten Erkrankungen wird auf Veränderungen in den 1994 bzw. 1995 identifizierten Genen BRCA1 und BRCA2 zurückgeführt. BRCA1 und BRCA2 spielen eine wesentliche Rolle in der zellulären Antwort auf DNA-Schäden und sind über die zahlreiche Interaktionspartner an mehreren Signalwegen beteiligt, die u. a. die Zellzykluskontrolle, das „Chromatin-Remodeling“ und den Proteinabbau über die Ubiquitinierung steuern. Der Nachweis einer BRCA1/2-Mutation hat erhebliche Implikationen für das Risiko, (erneut) an Brust- und Eierstockkrebs zu erkranken. Die Entwicklung zielgerichteter Therapieoptionen wird es in Zukunft unentbehrlich machen, bereits zum Zeitpunkt der Diagnosestellung zu wissen oder so schnell wie möglich zu ermitteln, ob eine BRCA1/2-Mutation vorliegt, um wirkungsvolle operative oder therapeutische Maßnahmen zu ergreifen.
Psychotropic drugs use and risk of heat-related hospitalisation
Authors: Martin-Latry Karin , Goumy Marie-Pierre , Latry Philippe , Gabinski Claude , Bégaud Bernard , Faure Isabelle , Verdoux Hélène 
Published: May 2007

AbstractObjectiveTo assess if use of psychotropic drugs is associated with an increased risk of admission for heat-related pathologies during a heat wave period.MethodWe conducted a matched case–control study. Cases were defined as subjects admitted to an emergency department for heat-related pathology (hyperthermia or heat stroke) over the August 2003 heat wave. Controls were defined as subjects living in the same area but not hospitalised over the same period and who had at least one prescription form submitted for refunding by the social security insurance in July 2003. Multivariate analyses were used to identify psychotropic drugs independently associated with hospital referral during the heat wave period.ResultsOut of the 1405 patients admitted to the emergency department, 56 (4%) presented with heat-related pathology. The mean age of cases was 83 years. Multivariate analyses showed that cases were more likely than controls to be treated with anticholinergic drugs (OR 6.0, 95% CI 1.8–19.6), antipsychotics (OR 4.6, 95% CI 1.9–11.2) or anxiolytics (OR 2.4, 95% CI 1.3–4.4).ConclusionIn special risk situations such as heat waves, the risk/benefit ratio of psychotropic drugs which could interfere with body temperature regulation has to be carefully assessed, particularly in the elderly.
Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian women
Authors: Bolca Selin , Possemiers Sam , Maervoet Veerle , Huybrechts Inge , Heyerick Arne , Vervarcke Stefaan , Depypere Herman , De Keukeleire Denis , Bracke Marc , De Henauw Stefaan , Verstraete Willy , Van de Wiele Tom 
Published: May 2007

Hop-derived food supplements and beers contain the prenylflavonoids xanthohumol (X), isoxanthohumol (IX) and the very potent phyto-oestrogen (plant-derived oestrogen mimic) 8-prenylnaringenin (8-PN). The weakly oestrogenic IX can be bioactivated viaO-demethylation to 8-PN. Since IX usually predominates over 8-PN, human subjects may be exposed to increased doses of 8-PN. A dietary intervention trial with fifty healthy post-menopausal Caucasian women was undertaken. After a 4 d washout period, participants delivered faeces, blank urine and breath samples. Next, they started a 5 d treatment with hop-based supplements that were administered three times per d and on the last day, a 24 h urine sample was collected. A semi-quantitative FFQ was used to estimate fat, fibre, alcohol, caffeine and theobromine intakes. The recoveries of IX, 8-PN and X in the urine were low and considerable inter-individual variations were observed. A five-fold increase in the dosage of IX without change in 8-PN concentration resulted in a significant lower IX recovery and a higher 8-PN recovery. Classification of the subjects into poor (60 %), moderate (25 %) and strong (15 %) 8-PN producers based on either urinary excretion or microbial bioactivation capacity gave comparable results. Recent antibiotic therapy seemed to affect the 8-PN production negatively. A positive trend between methane excretion and 8-PN production was observed. Strong 8-PN producers consumed less alcohol and had a higher theobromine intake. From this study we conclude thatin vivoO-demethylation of IX increases the oestrogenic potency of hop-derived products.
Bubble rise in a liquid with a surfactant gas, in particular carbon dioxide
Authors: HARPER J. F. 
Published: May 2007

When a gas bubble rises in a surfactant solution, the velocity field and the distribution of surfactant affect each other. This paper gives the theory for small Reynolds and internal Péclet numbers if the surfactant is gaseous or volatile, if its mass flux across the bubble and around its surface dominates its mass flux through the bulk liquid, and if slowness of both adsorption and convective diffusion must be allowed for.The theory is tested on the experiments of Kelsall et al. (J. Chem. Soc. Faraday Trans., vol. 92, 1996, p. 3879). Their bubbles rose as expected in a pure liquid until the apparatus was opened to the atmosphere. That significantly slowed the bubbles down. The effect is so sensitive to small concentrations of slowly adsorbing or reacting surfactants that atmospheric carbon dioxide could have caused it, even though it alters the equilibrium surface tension by less than four parts per million in pure air.There are still unexplained discrepancies between experiment and theory. Additional experiments are suggested that would help to explain them.
Pilot comparison between potassium titanyl phosphate laser and bipolar radiofrequency in paediatric tonsillectomy
Authors: Hegazy H M , Albirmawy O A , Kaka A H , Behiry A S 
Published: May 2007

AbstractObjectives:To compare the advantages and disadvantages of potassium titanyl phosphate laser with those of bipolar radiofrequency techniques, in paediatric tonsillectomy.Study design:Prospective, randomised, clinical study.Patients and methods:From July 2004 to April 2006, 80 patients aged between 10 and 15 years, with tonsillectomy planned for chronic tonsillitis, were included in the study. Children were prospectively randomised into two equal groups: potassium titanyl phosphate laser tonsillectomy and bipolar radiofrequency tonsillectomy. Operative time and intra-operative blood loss were recorded. Patients were scheduled for follow up during the first, second and fourth post-operative weeks. They were asked to record their pain and discomfort on a standardised visual analogue scale, from zero (no pain) to 10 (severe pain). Post-operative complications were also recorded and managed.Results:The potassium titanyl phosphate laser group showed a slightly longer operative time (mean 12 minutes) than the bipolar radiofrequency group (mean 10 minutes). Intra-operative blood loss was significantly less in the potassium titanyl phosphate laser group (mean 21 cm3) than in the bipolar radiofrequency group (mean 30 cm3). In the first week, post-operative pain scores were less in the potassium titanyl phosphate laser group than in the bipolar radiofrequency group (means 7.5 and 8.5, respectively). However, in the second week pain scores increased more in the potassium titanyl phosphate laser group than in the bipolar radiofrequency group (means 8.5 and 6, respectively). In the fourth week, both groups showed equal and nearly normal pain scores. No case of reactionary post-tonsillectomy haemorrhage was recorded in either group. Only one case of secondary post-tonsillectomy haemorrhage was recorded, in the potassium titanyl phosphate laser group (2.5 per cent), managed conservatively.Conclusion:Both the potassium titanyl phosphate and the bipolar radiofrequency techniques were safe and easy to use for tonsillectomy, with reduced operative time, blood loss and complication rates and better post-operative general patient condition. Potassium titanyl phosphate laser resulted in reduced operative bleeding and immediate post-operative pain, compared with the bipolar radiofrequency technique. However, potassium titanyl phosphate laser required slightly more operative time and caused more late post-operative pain than the bipolar radiofrequency technique. The low rate of recorded complications showed that both techniques cause little damage to the tonsillar bed during dissection, thus minimising complications.
Non-recurrent laryngeal nerve related to thyroid surgery: report of three cases
Authors: Page C , Monet P , Peltier J , Bonnaire B , Strunski V 
Published: May 2007

AbstractPurpose of the study:We aimed to highlight a rare anatomical variation involving the recurrent laryngeal nerve, and to emphasise its implications for thyroid surgery.Materials and methods:Over a period of 13 years, 993 patients underwent thyroid surgery; 1557 recurrent laryngeal nerves (887 on the right side) were exposed.Results:Three non-recurrent laryngeal nerves were found on the right side, associated with a retro-oesophageal subclavian artery. One case was suspected before surgery.Discussion:Several variations in the path and branches of the recurrent laryngeal nerve have been reported in the literature. The frequency of occurrence of a non-recurrent laryngeal nerve is about 1 per cent, for patients undergoing thyroid surgery. Other surgically relevant anatomical variations of the recurrent laryngeal nerve include associations with the inferior thyroid artery and the presence of nerve branches.Conclusion:The recurrent laryngeal nerve must be carefully dissected and totally exposed during thyroid surgery in order to best preserve its function. Moreover, the thyroid surgeon must be aware of the existence of anatomical variations, which are not as rare as one may think.
Explicit diagonalization of the Markov form on the
Temperley–Lieb algebra
Authors: GENAUER JOSH , STOLTZFUS NEAL W. 
Published: May 2007

AbstractIn a fundamental paper in 1984, Vaughan Jones developed his new polynomial
invariant of knots using a Markov trace on the Temperley–Lieb
algebra. Subsequently, Lickorish used the associated bilinear pairing to
provided an alternative proof for the existence of the 3-manifold invariants of
Witten, Reshetinkin and Turaev. A key property of this form is the
non-degeneracy of this form except at the parameter values
±2cos(π/(n+1)) [7]. Ko
and Smolinsky derived a recursive formula for the determinants of specific
minors of Markov's form, establishing the needed non-degeneracy
[6]. In this paper,
we define a triangular change of basis in which the form is diagonal and
explicitly compute the diagonal entries of this matrix as products of quotients
of Chebyshev polynomials, corroborating the determinant computation of Ko and
Smolinsky. The method of proof employs a recursive method for defining the
required orthogonal basis elements in the Temperley–Lieb algebra,
similar in spirit to Jones' and Wenzl's recursive formula
for a family of projectors in the Temperley–Lieb algebra. We define a
partial order on the non-crossing chord diagram basis and give an explicit
formula for a recursive construction of an orthogonal basis, via a recursion
over this partial order. Finally we relate this orthogonal basis to bases
constructed using the calculus of trivalent graphs developed by Kauffman and
Lins [5].
A strict totally coordinatized version of Kapranov and Voevodsky's 2-category 2Vect
Authors: ELGUETA JOSEP 
Published: May 2007

AbstractIn this paper we describe the 2-category 2Mat of 2-matrices, i.e., a strict totally coordinatized version of the 2-category 2Vect of Kapranov and Voevodsky finite dimensional 2-vector spaces, analogous to the category Mat of matrices which appears as the coordinatized version of the category Vect of finite dimensional vector spaces. In particular, explicit formulas for the composition of 1-morphisms and the two compositions between 2-morphisms are given.
Quantum stochastic operator cocycles via associated semigroups
Authors: LINDSAY J. MARTIN , WILLS STEPHEN J. 
Published: May 2007

AbstractA recent characterisation of Fock-adapted contraction operator stochastic cocycles on a Hilbert space, in terms of their associated semigroups, yields a general principle for the construction of such cocycles by approximation of their stochastic generators. This leads to new existence results for quantum stochastic differential equations. We also give necessary and sufficient conditions for a cocycle to satisfy such an equation.
A Whitehead–Ganea approach for proper Lusternik–Schnirelmann category
Authors: GARCÍA–CALCINES J. M. , GARCÍA–DÍAZ P. R. , MAS A. MURILLO 
Published: May 2007

AbstractWe establish Whitehead and Ganea characterizations for proper LS-category. We use the embedding of the proper category into the exterior category, and construct in the latter a suitable closed model structure of Strøm type. Then, from the axiomatic LS-category arising from the exterior homotopy category we can recover the corresponding proper LS invariants. Some applications are given.
On the topology defined by Thurston's asymmetric metric
Authors: PAPADOPOULOS ATHANASE , THÉRET GUILLAUME 
Published: May 2007

AbstractWe establish some properties of Thurston's asymmetric metric L on the Teichmüller space ${\cal T}_{\frak{g},\frak{n}}$ of a surface of genus $\frak{g}$ with $\frak{n}$ punctures and with negative Euler characteristic. We study convergence of sequences of elements in ${\cal T}_{\frak{g},\frak{n}}$ in the sense of L, as well as sequences that tend to infinity in ${\cal T}_{\frak{g},\frak{n}}$. We show that the topology that the asymmetric metric L induces on Teichmüller space is the same as the usual topology. Furthermore, we show that L satisfies the axioms of a (not necessarily symmetric) metric in the sense of Busemann and conclude that L is complete in the sense of Busemann.
Brunnian links, claspers and Goussarov–Vassiliev finite type invariants
Authors: HABIRO KAZUO 
Published: May 2007

AbstractGoussarov and the author independently proved that two knots in S3 have the same values of finite type invariants of degree <n if and only if they are Cn-equivalent, which means that they are equivalent up to modification by a kind of geometric commutator of class n. This property does not generalize to links with more than one component.In this paper, we study the case of Brunnian links, which are links whose proper sublinks are trivial. We prove that if n ≥ 1, then an (n+1)-component Brunnian link L is Cn-equivalent to an unlink. We also prove that if n ≥ 2, then L can not be distinguished from an unlink by any Goussarov–Vassiliev finite type invariant of degree <2n.
The horofunction boundary of finite-dimensional normed spaces
Authors: WALSH CORMAC 
Published: May 2007

AbstractWe determine the set of Busemann points of an arbitrary finite-dimensional normed space. These are the points of the horofunction boundary that are the limits of “almost-geodesics”. We prove that all points in the horofunction boundary are Busemann points if and only if the set of extreme sets of the dual unit ball is closed in the Painlevé–Kuratowski topology.
Site fidelity of Weddell seals: the effects of sex and age
Authors: Cameron Michael F. , Siniff Donald B. , Proffitt Kelly M. , Garrott Robert A. 
Published: May 2007

AbstractSite fidelity is believed to be an important life history strategy for Weddell seals (Leptonychotes weddellii), that return to traditional breeding colonies each spring. We examined four hypotheses concerning their fidelity to these colonies: 1) fidelity is stronger to natal sites (natal fidelity) than to other sites, 2) females exhibit greater site fidelity than males, 3) site fidelity for both sexes increases with age, 4) site fidelity in adult females is related to their reproductive status and their total number of offspring. Analysis of a long-term tagging database from McMurdo Sound did not support hypotheses 1 and 2. Although animals did express fidelity to specific sites over their lifetime (χ2 tests, P < 0.05), fidelity to natal colonies was lower than to other sites (χ2 test, P < 0.05). There were no differences in site fidelity between males and females (χ2 tests, P > 0.05). Hypothesis 3 was supported. Since the probability of a returning seal occupying the same colony as the previous year increased with age among both sexes to about age 12. Finally, in support of hypothesis 4, females with a higher degree of site fidelity were more likely to both have a higher reproductive rate and return to a site where they have previously given birth.