bluuebunny/crossref_metadata_2025_split huggingface dataset:
MANY MASSES ON ONE STROKE: ECONOMIC COMPUTATION OF QUARK PROPAGATORS
Authors: FROMMER ANDREAS , NÖCKEL BERTOLD , GÜSKEN STEPHAN , LIPPERT THOMAS , SCHILLING KLAUS 
Published: November 2004

The computational effort in the calculation of Wilson fermion quark propagators in Lattice Quantum Chromodynamics can be considerably reduced by exploiting the Wilson fermion matrix structure in inversion algorithms based on the non-symmetric Lanczos process. We consider two such methods: QMR (quasi minimal residual) and BCG (biconjugate gradients). Based on the decomposition M/κ = 1/κ−D of the Wilson mass matrix, using QMR, one can carry out inversions on a whole trajectory of masses simultaneously, merely at the computational expense of a single propagator computation. In other words, one has to compute the propagator corresponding to the lightest mass only, while all the heavier masses are given for free, at the price of extra storage. Moreover, the symmetry γ5M = M†γ5 can be used to cut the computational effort in QMR and BCG by a factor of two. We show that both methods then become — in the critical regime of small quark masses — competitive to BiCGStab and significantly better than the standard MR method, with optimal relaxation factor, and CG as applied to the normal equations.
QUASI TWO-BODY DECAYS OF CHARM MESONS
Authors: TERASAKI K. 
Published: November 2004

Quasi two-body decays of charm mesons are studied by using a hard-meson approximation in which the amplitude M is given by M≃METC+MS. The surface term MS is given by a sum of all possible pole amplitudes involving contributions of four-quark and hybrid mesons in addition to ground-state [Formula: see text] mesons. Contributions of multihadron intermediate states are taken in the form of METC. The spectator type of decays can have significant contributions of s-channel poles of four-quark mesons. In the annihilation type of decays, s-channel hybrid-meson poles can play an important role. The mixed type of decays can have all the pole contributions of the ground-state [Formula: see text], possible hybrid and four-quark mesons in the s-channel. The estimated branching ratios, [Formula: see text] and [Formula: see text] are of ordinary size, in contrast with the factorization which predicts very large rates for these decays. The [Formula: see text] and [Formula: see text] decays can be suppressed in consistency with the other decays.
AN ANALYTICAL SOLUTION OF A SECOND KIND VOLTERRA INTEGRAL EQUATION REPRESENTING THE CONTRIBUTION OF GRAVITATIONAL WAVES TO THE POLARIZATION OF THE COSMIC MICROWAVE BACKGROUND
Authors: GIBILISCO MARINA 
Published: November 2004

Volterra integral equations of the second kind have a remarkable importance in many physical problems. In this paper, I shall discuss the particular case of a Volterra equation whose solution represents the polarization of the cosmic microwave background (CMB) induced by cosmological gravitational waves. The analytical study of the radiative transfer equation, written in the Chandrasekhar formalism, is performed after a change of variables that follows the formalism developed by Polnarev in 1980. Then, the problem turns into the solution of a second kind Volterra equation, containing the gravitational wave spectrum in its source term. An analytical solution for this Volterra equation can be found if its kernel has a polynomial or an exponential form: in these cases, respectively, the methods of the resolvent and of the iterated kernels can be successfully applied; the solution thus determined represents the polarization of the CMB photons induced by cosmological gravitational waves. The calculated polarization degree for the CMB is plotted versus the wave number k of the gravitational waves inducing the polarization. In the case of an exponential kernel, i.e. for a Universe fast reionized at small redshift (z≤20), I obtain a remarkable polarization peak at small k (k≤4); such a degree of polarization for the CMB should be observable at angular scales near 9°, thus providing also a test for many reionization models. On the contrary, for a standard ionization history, a CMB polarization comparable in magnitude to the one predicted above could only be observed at small angular scales (θ≤2°).
CONSTRAINED ANNEALING FOR SYSTEMS WITH QUENCHED DISORDER
Authors: PALADIN GIOVANNI , PASQUINI MICHELE , SERVA MAURIZIO 
Published: November 2004

We review a method for the study of systems with quenched disorder, such as Ising models with random field or coupling, by means of annealed averages where appropriate constraints are imposed. It allows one to understand the role of the intensive variables of the disorder (mean magnetic field, impurities concentration, frustration…) and improves the annealed approximation of the quenched free energy. The constrained annealing can be obtained by introducing generalized Gibbs-like potential depending on Lagrangian multipliers associated to the intensive variables of the disorder. The minimum of the potential gives a lower bound of the quenched free energy which can be a very accurate estimate for a proper choice of the constraints. The method is first applied to one-dimensional Ising models with random magnetic fields. In this case the frustration is properly taken into account and the quenched free energy density is estimated with a precision higher than the numerical results. As a first step to higher dimensional model we then introduce an Ising model with two competing interactions: nearest neighbour random couplings and a positive infinite range coupling. At low temperature the model exhibits a new type of non-trivial ‘ferrimagnetic’ order in a region of low temperatures and intermediate disorder strength. The qualitative features of the model (in particular the phase transition line between ferromagnetic and ferrimagnetic phases) is reproduced by the constrained annealing. Finally we apply our method to d-dimensional Ising models with random nearest neighbour coupling. In this case, we also introduce an alternative new way to obtain constrained annealed averages without recurring to the Lagrange multipliers. It requires to perform quenched averages on small volumes, in a analytic or numerical way. We thus give a sequence of converging lower bounds for the quenched free energy. In particular, in 2d the known analytic estimates are considerably improved.
THE VAN HOVE SINGULARITY IN HIGH Tc SUPERCONDUCTORS
Authors: HORBACH M.L. , KAJÜTER H. 
Published: November 2004

Experimental indications for the role of the van Hove singularity (vHs) in the electronic density of states of high Tc superconductors are discussed. It is argued that (i) like the resistivity, the measured temperature and doping dependences of the normal state electronic specific heat of YBCO are consistent with the existence of a vHs and (ii) the doping dependence of Tc in the underdoped and optimally doped regimes may be accounted for mainly by a vHs. Further, we discuss the suppression of the quasiparticle scattering rate below Tc, and the coherence lengths in the hole-doped materials and NCCO. Assuming that the same mechanism for superconductivity operates in the electron-doped and the hole-doped cuprates, we argue that the bosonic mode that causes the superconductivity is strongly influenced by the doping in the overdoped regime. We further argue that this boson involves an energy scale larger than that of phonons and is only weakly coupled to the charge carriers.
TESTING THE ROBUSTNESS OF THE STEADY-STATE CHARACTERISTICS OF A METABOLIC PATHWAY: PARAMETER SENSITIVITIES AS A BASIC FEATURE FOR MODEL VALIDATION
Authors: CASCANTE MARTA , CURTO RAUL , SORRIBAS ALBERT 
Published: November 2004

Mathematical models are useful for analyzing metabolic problems. To build up these models, we need: (1) A scheme of the target system, (2) Measurements of concentrations and fluxes in steady-state, (3) The rate law of each reaction and (4) The set of differential equations that reflects the model behaviour. Usually, the rate-laws are identified from in vitro data, which could result in unrealistic models when compared with the behavior of the intact system. Hence, mathematical models must be carefully validated before one can trust their behavior. We can use different features of a biological system as a reference for validating a model. The steady-state robustness to parameter changes can be used as an index for such an evaluation. In this sense, a realistic model should reflect a fundamental property of a living system: small perturbations are compatible with system performance. We present an example of such analysis in the case of the ethanolic fermentation pathway of Saccharomyces cerevisiae. The parameter sensitivities of the model are computed in two experimental conditions and a diagnostic is made on the validity of the corresponding model. Translation of the mechanistic model into an S-system model facilitates the analysis of parameter sensitivity. After the analysis, a high parameter sensitivity suggest the need for a careful estimation of the involved parameters.
NONLINEAR MATHEMATICAL MODELS OF HORMONAL SYSTEMS
Authors: NAUROSCHAT J. , AN DER HEIDEN U. 
Published: November 2004

The paper considers various approaches to mathematical modelling of endocrine systems. The functional and operational complexity of hormonal activities turns out to be the result of the cooperation of three factors: global feedback structures on the level of glands, subtle feedback and regulatory mechanisms on the level of single cells and molecules (including messengers, receptors and functional proteins like G-proteins) and finally, coupling to other organs (predominantly to the brain, e.g. via hypothalamus). To date, it is practically impossible to construct a mathematical model comprising together all these aspects. The paper aims at providing some major building bricks to such an endeavor. In the first part we summarize some of our recent models on the gobal structure of hormonal systems, in the form of nonlinear differential equations containing delay terms; oscillatory input from the brain is taken into account. Solutions of the equations display nearly all kinds of dynamical behaviour as stable limit cycles, phase locking, quasi-periodic and chaotic motions. Special emphasis is put on developing a mathematical model for the fine-tuned sequence of hormone-induced transmembrane signalling, where agonist couples to some cellular effector via transfer-proteins — this principle is widely spread among the hormone-targeted cells and crucially involved in regulating cells' behaviour towards external stimuli, e.g. their ability to desensitize as a reaction to sustained hormonal input.
A 2-DIMENSIONAL MODEL FOR MACROPARASITIC INFECTIONS IN A HOST WITH LOGISTIC GROWTH
Authors: PUGLIESE ANDREA , ROSÀ ROBERTO 
Published: November 2004

We analysed a model for the interaction of a macroparasite and a host population growing logistically. The model is obtained by approximating the parasite distribution with a negative binomial with a fixed clumping parameter. By letting the contact rate k vary, we found a complex pattern of bifurcations, including subcritical bifurcations of the disease-free equilibrium, Hopf and homoclinic bifurcations. The specific pattern depends on the interaction of the various parameters; in particular, alternative stable equilibria may occur only when the carrying capacity KN is sufficiently large, while periodic solutions may occur for all values of KN, if k is large enough.
HOW TO MAKE GOOD USE OF MULTILAYER NEURAL NETWORKS
Authors: PAUGAM-MOISY HÉLÈNE 
Published: November 2004

This article is a survey of recent advances on multilayer neural networks. The first section is a short summary on multilayer neural networks, their history, their architecture and their learning rule, the well-known back-propagation. In the following section, several theorems are cited, which present one-hidden-layer neural networks as universal approximators. The next section points out that two hidden layers are often required for exactly realizing d-dimensional dichotomies. Defining the frontier between one-hidden-layer and two-hidden-layer networks is still an open problem. Several bounds on the size of a multilayer network which learns from examples are presented and we enhance the fact that, even if all can be done with only one hidden layer, more often, things can be done better with two or more hidden layers. Finally, this assertion 'is supported by the behaviour of multilayer neural networks in two applications: prediction of pollution and odor recognition modelling.
In utero Meconium SuctioningMay Prevent Meconium As piration
Authors: Petrikovsky Boris 
Published: November 2004

<i>Objective: </i>To assess usefulness of in utero meconium suctioning using endoscopic approach. <i>Materials and Methods:</i> In utero meconium suctioning under direct endoscopic visualization was successfully performed in 11 fetuses in whom thick meconium was detected upon rupture of the membranes. A gas-sterilized flexible fiberoptic scope with an operational channel was introduced via cervix, and meconium was aspirated from the fetal mouth. Definitive suction was performed in all neonates immediately after birth. <i>Results:</i> Endoscopic meconium suctioning was successfully performed in 11 out of 16 fetuses with retrieval of 3–12 ml of meconium. Only 1 neonate in this series of cases had meconium below the vocal cords and none developed meconium aspiration syndrome postnatally. <i>Conclusion:</i> Because fatal meconium aspiration syndrome is largely an intrauterine event, the concept of in utero prophylactic meconium suctioning may serve as an effective modality for its prevention.
Effects of Two Fluoridation Measures on Erosion Progression in Human Enamel and Dentine in situ
Authors: Ganss C. , Klimek J. , Brune V. , Schürmann A. 
Published: November 2004

The aim of the present study was to evaluate the effects of fluoride on erosive mineral loss in human enamel and dentine using a cyclic de- and remineralisation model in situ. The study was a three-treatment (5 days each) crossover design involving 4 (enamel) or 6 (dentine) healthy volunteers. Samples were recessed in palatal mouth appliances and worn day and night except during meals and were demineralised extraorally with 0.05 <i>M</i> citric acid (pH 2.3) for 6 × 5 min daily. Fluoridation was performed with toothpaste (SnF<sub>2</sub>/Olaflur; 0.14% F<sup>–</sup>) for 3 × 5 min daily (toothpaste fluoridation) or with toothpaste in combination with a mouthrinse (SnF<sub>2</sub>/Olaflur; 0.025% F<sup>–</sup>) for 3 × 5 min daily and with a gel (NaF/Olaflur, 1.25% F<sup>–</sup>) on days 1 and 3 instead of the toothpaste (intensive fluoridation). In the control group no fluoridation was performed. Mineral loss (µm) was determined with the use of longitudinal microradiography. In enamel, mineral loss was 40.7 ± 15.1 µm in the control group, 18.3 ± 12.4 µm after toothpaste fluoridation and 5.0 ± 12.2 µm after intensive fluoridation. The respective values for dentine were 49.0 ± 15.4, 35.0 ± 15.5 and 19.8 ± 12.0 µm. All differences were statistically significant (p ≤ 0.001). The results indicate that intensive fluoridation is effective in preventing enamel and dentine from mineral loss even under severely erosive conditions.
Capecitabine with Weekly Paclitaxel for Advanced Breast Cancer: A Phase I Dose-Finding Trial
Authors: Uhlmann Catrina , Ballabeni Pierluigi , Rijken Natalie , Brauchli Peter , Mingrone Walter , Rauch Daniel , Pestalozzi Bernhard C. , Rochlitz Christoph , Aebi Stefan 
Published: November 2004

<i>Objective:</i> To determine the maximum tolerated dose (MTD), toxicity and activity of combined weekly paclitaxel and capecitabine in patients with metastatic breast cancer. <i>Methods:</i> Sixteen patients with metastatic breast cancer, of whom 15 were evaluable for toxicity and response, were enrolled in 7 Swiss centers. Paclitaxel 80 mg/m<sup>2</sup> was given intravenously on days 1, 8 and 15. Capecitabine was administered orally on days 1 through 14 using five different dose levels. Both drugs were given in a 21-day schedule. <i>Results:</i> Capecitabine could be administered at doses commonly used for the drug as a single agent, i.e. 1,250 mg/m<sup>2</sup> twice daily in combination with weekly paclitaxel. Hematological and other toxicities did not appear to be dose-limiting; however, significant skin and nail toxicities were observed. A response or stable disease was observed in 87% of patients [13/15; exact 95% confidence interval (CI) 60–98%], with 2 complete responses, 4 partial responses (overall response rate 40%, exact 95% CI 16–68%) and 7 patients with stable disease for at least 9 weeks. <i>Conclusion:</i> The phase I evaluation of capecitabine in combination with fixed-dose weekly paclitaxel did not allow the definition of an MTD of capecitabine based on the predefined criteria. Instead, the dose for the phase II evaluation was determined based on the occurrence of toxicity in later courses and on experience with other regimens containing capecitabine. Capecitabine (1,000 mg/m<sup>2</sup> twice daily, days 1–14, every 3 weeks) with paclitaxel (80 mg/m<sup>2</sup> weekly) is a promising combination for advanced breast cancer now being investigated in a phase II trial.
Transdermal Iontophoresis of Insulin
Authors: Pillai O. , Panchagnula R. 
Published: November 2004

The delivery of large peptides through the skin poses a significant challenge, and various strategies are under active investigation for enhancing the transdermal permeation. For large peptides, it is difficult to achieve significant permeation using iontophoresis alone. Hence a combination of fatty acids with iontophoresis was hypothesized to result in higher enhancement than achieved with either of them alone. Saturated fatty acids and <i>cis</i> unsaturated fatty acids were studied in combination with iontophoresis using excised rat skin. The skin was pretreated for 2 h with an ethanolic (EtOH) solution of 5% w/v or v/v fatty acids, namely lauric acid (LA), oleic acid (OA), linoleic acid (LOA) and linolenic acid (LLA), followed by either passive or iontophoretic permeation (0.5 mA/cm<sup>2</sup> for 6 h). Fourier transform infrared spectroscopy (FT-IR) was used to investigate the biophysical changes on treatment with fatty acid/EtOH or neat fatty acid, mainly focusing on the infrared region at 2,920, 1,710 and 1,720 cm<sup>–1</sup>. Unsaturated fatty acids showed higher enhancement than LA, and the enhancement increased with the number of double bonds. On the other hand, in the presence of iontophoresis, LA/EtOH showed the highest enhancement. Neat LOA did not show any significant difference (p > 0.05) compared to the LOA/EtOH combination. FT-IR studies revealed that fatty acids act by interacting with the skin lipids. All the fatty acids showed synergistic enhancement when combined with iontophoresis. The flux enhancement was highest with LA, which in the presence of iontophoresis showed 20 times enhancement of insulin flux in comparison to passive flux and 9 times enhancement as compared to iontophoresis alone. Flux enhancement of unsaturated fatty acids was in the following decreasing order LOA > OA > LLA.
Efficacy of Quinupristin-Dalfopristin against Methicillin-Resistant <i>Staphylococcus aureus</i> and Vancomycin-Insensitive <i>S. aureus</i> in a Model of Hematogenous Pulmonary Infection
Authors: Yanagihara Katsunori , Okada Makiko , Fukuda Yuichi , Imamura Yoshifumi , Kaneko Yukihiro , Ohno Hideaki , Higashiyama Yasuhito , Miyazaki Yoshitsugu , Tsukamoto Kazuhiro , Hirakata Yoichi , Tomono Kazunori , Kadota Jun-Ichi , Tashiro Takayoshi , Murata Ikuo , Kohno Shigeru 
Published: November 2004

<i>Background:</i> Quinupristin-dalfopristin (Q-D) is a mixture of quinupristin and dalfopristin, which are semisynthetic antibiotics of streptogramin groups B and A, respectively. <i>Methods:</i> We compared the effect of Q-D to that of vancomycin (VCM) in murine models of hematogenous pulmonary infections caused by methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and VCM-insensitive <i>S. aureus</i> (VISA). <i>Results:</i> Treatment with Q-D resulted in a significant decrease in the number of viable bacteria in the lungs of mice in an MRSA infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean ± SEM): 2.99 ± 0.44, 6.38 ± 0.32, 5.75 ± 0.43 and 8.40 ± 0.14 log<sub>10</sub> CFU/lung, respectively]. Compared with VCM, high-dose Q-D significantly reduced the number of bacteria detected in the VISA hematogenous infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean ± SEM): 5.17 ± 0.52, 7.03 ± 0.11, 7.10 ± 0.49 and 7.18 ± 0.36 log<sub>10</sub> CFU/lung, respectively]. Histopathological examination confirmed the effect of Q-D. <i>Conclusion:</i> Our results suggest that Q-D is potent and effective in the treatment of MRSA and VISA hematogenous pulmonary infections.
Reading Jesus Writing
Authors: Aichele George 
Published: November 2004

AbstractThis essay explores the problematic story of the "woman taken in adultery" (John 7:53-8:11) in relation to logocentric structures that define the Gospel of John. Jesus's two acts of writing on the ground, unique to this story, point to texts that we cannot read and which are therefore unable to signify. I suggest that Jesus's earthy texts do eventually appear in John's Gospel, where they reassure the reader that the Gospel has after all succeeded sufficiently in its task of signifying the incarnation of the pre-existent Word, even as they announce the inherent finitude and incompleteness of any text.
John Chrysostom, Rhetoric and Galatians
Authors: Heath Malcolm 
Published: November 2004

AbstractThis paper examines the influence of contemporary rhetoric on John Chrysostom's commentary on Galatians (with some reference to other exegetical works). Because ancient rhetoric developed over time, the primary points of reference are works on rhetorical theory, commentaries on Demosthenes and rhetorical exercises dating to the second century ce and later. It is argued that modern attempts to classify the letter under the three standard classes of oratory are misconceived in terms of ancient theory, but that this is not an obstacle to rhetorical analysis. John's use of rhetorical concepts in analysing the structure of the letter is illustrated, as is his use of the pattern of counterposition (an objection attributed to an opponent) and solution, both as a compositional device and as an exegetical tool. In his interpretation of Gal. 2:1-10, John argues Paul is unable to deal fully with counterpositions because of the constraints entailed by a covert strategy agreed by the apostles at the Jerusalem consultation. John's interpretation of the confrontation with Peter at Antioch, according to which Peter pretended to give way to Paul's opponents in order to give him an opportunity to respond, is shown to be based on the rhetorical concept of figured speech. John's attention to Paul's management of the relationship with his addressees is examined. The admiration which John expresses for this and other aspects of Paul's rhetorical technique is shown to echo, in content and phrasing, similar expressions of admiration in commentaries on Demosthenes originating in contemporary rhetorical schools.