bluuebunny/crossref_metadata_2025 huggingface dataset:
A stoichiometric model of Acidithiobacillus ferrooxidans ATCC 23270 for metabolic flux analysis
Authors: Hold C. , Andrews B.A. , Asenjo J.A.
Published: October 2008

A stoichiometric model of Acidithiobacillus ferrooxidans based on the sequenced genome from strain ATCC 23270 is derived and parameterized using genome/pathway databases. The model describes the main aspects of catabolism and anabolism. By the construction and utilization of the mathematical determination of the network, metabolic flux analysis is performed for such a bacterium for the first time and results are successfully verified by comparison to literature values. This first metabolic model of A. ferrooxidans is able to simulate the main aspects of metabolism and will be useful for further investigation and improvement of bioleaching procedures. Biotechnol. Bioeng. 2009;102: 1448–1459. © 2008 Wiley Periodicals, Inc.
Bulky Pyrazolate‐Based Compartmental Ligand Scaffolds: Encapsulation of an Edge‐Sharing Cu6O2 Bitetrahedral Core
Authors: Sachse Anna , Noël Gilles , Dechert Sebastian , Demeshko Serhiy , Honecker Andreas , Alfonsov Alexei , Kataev Vladislav , Meyer Franc
Published: October 2008

Upon reaction with Cu(OAc)2·H2O, pyrazole‐based ligands with two appended imine chelate arms in the 3‐ and 5‐positions of the pyrazole and bulky substituents at the imine‐N yield Cu6 complexes [L2Cu6(μ‐OAc)6(μ4‐O)2] (1a,b). They feature an unusual {Cu6(μ4‐O)2}‐bitetrahedral core, only the second example of this structural motif. ESI mass spectrometric and UV/Vis data confirm that the Cu6 complexes stay intact in solution, and magnetic and high‐field EPR measurements reveal an S = 0 ground state with the first excited triplet at ΔE ≈ 95 cm–1. Although the new hexanuclear systems are too complex for deriving all individual exchange constants from powder susceptibility data, a rough idea of the complete energy level spectrum could be obtained.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A probabilistic evaluation of wind turbine fatigue design rules
Authors: Veldkamp Dick
Published: October 2008

In wind turbine fatigue design, it is customary to use the partial safety factor approach: loads are inflated by some factor, while material fatigue strength is decreased in calculations. Values for partial factors used originally come from civil engineering standards for utility buildings and bridges, and it is not clear that they are optimal for wind turbines. In the paper, an inventory of important stochastic parameters influencing fatigue loads is given, and their estimated distributions are presented. With this information, failure probabilities due to fatigue are determined, as well as the relative importance of the stochastic parameters for total uncertainty. Using a simple cost model, economically optimal failure probabilities and partial factors are derived. The main conclusion of the presented work is that uncertainties in material fatigue properties and life prediction methods dominate total uncertainty, and hence determine the required partial factors. Copyright © 2008 John Wiley & Sons, Ltd.
Le marché dans l'économie de la grèce antique
Authors: Descat Raymond
Published: October 2008

Le marché constitue le point crucial du débat qui a régné depuis le xvme siècle dans l'histoire de l'économie antique. La question a été rendue particulièrement complexe pour le monde grec parce que beaucoup d'historiens et d'anthropologues (comme Karl Polanyi) y situent la naissance de l'économie de marché comme une rupture avec la période antérieure. L'histoire doit abandonner une position trop dogmatique sur cette émergence du marché et considérer d'abord les étapes de la constitution d'une place de marché, l'agora, à partir de la fin de l'époque archaïque. La cité grecque intervient de cette manière dans les échanges. Dans cet article sont étudiées ces interventions sur les conditions de la vente et de lachat, les pratiques, les valeurs et les prix, les approvisionnements, afin de comprendre l'innovation réelle que cela représente.
Travail, redistribution et construction des espaces économiques (XIe-XVe siècle)
Authors: Arnoux Mathieu
Published: October 2008

Longtemps objet de prédilection des historiens de l'économie européenne, la croissance médiévale n'est plus au centre de leurs préoccupations. En la replaçant dans une perspective de long terme, du XIe au XVe siècle, et en s'interrogeant sur ce qui en elle relève proprement des processus de développement ou des dynamiques conjoncturelles, il est possible de replacer au centre du débat historique un moment essentiel de construction de l'économie-monde européenne. L'article insiste en particulier sur l'importance des processus sociaux de promotion des activités productives et des groupes de travailleurs: ils ont rendu possible une intensification du travail, rémunérée par un ensemble complexe de mécanismes de redistribution des richesses qui sont l'une des créations originales des sociétés médiévales.
L'impensé du marché
Authors: Gervais Pierre
Published: October 2008

L'historiographie des États-Unis de la fin du XVIIIe siècle et du premier XIXe siècle est caractérisée par l'accent mis sur le rôle essentiel du développement du marché dans la croissance économique. Les différentes écoles s'opposent sur l'importance de l'économie morale non-marchande (ou économie du foyer), et le rythme et l'ampleur de l'intégration des marchés. Pourtant, du fait de la chronologie du développement économique du pays, différente de celle observée en Grande-Bretagne, cette intégration, plus que l'évolution technique, a dans l'ensemble toujours été considérée comme la source première de la révolution industrielle et du capitalisme industriel. Mais la notion même de marché, elle, n'ajamais été critiquée et historicisée. L'article propose un modèle historiquement déterminé de fonctionnement marchand et avance quelques hypothèses sur la transition au capitalisme industriel.
Les signes de qualité
Authors: Stanziani Alessandro
Published: October 2008

Cet article étudie le lien entre confiance et réputation, règles de droit et normes informelles dans la détermination de la qualité des produits et des acteurs économiques. Après avoir rappelé les principales approches et solutions à ces problèmes avancés par l'historiographie, mais aussi par la sociologie et l'économie, nous étudierons le marché du vin en France au XIXe siècle. Nous mettrons l'accent sur le rôle que normes et confiance ont joué pendant le dernier quart du XIXe siècle, en réponse au phylloxéra, d'une part, aux progrès techniques et au développement des marchés internationaux, de l'autre. Nous évaluerons enfin le débat et les pratiques autour des marques viticoles (individuelles et collectives) tout au long du XIXe siècle. Cette analyse nous permettra de développer les questions du lien entre la protection de la propriété individuelle, la confiance ancrée dans le territoire et la dynamique des marchés. Notre principal argument sera que normes, confiance et réputation sont moins des substituts les unes des autres que complémentaires dans le fonctionnement des marchés. La confiance s'inscrit dans un cadre institutionnel et cognitif précis sans lequel elle ne saurait intervenir dans la coordination des marchés.
Marchés des produits de luxe et division internationale du travail (XIXe-XXe Siècles)
Authors: Verley Patrick
Published: October 2008

Cet article aborde la question des changements, dans la très longue durée, de la division internationale du travail à partir d'un observatoire qui est l'échange de produits de luxe. Cette approche est loin d'être mineure, car le commerce international s'est structuré, à l'époque moderne, à partir de ces produits de prix élevé. Dans la première moitié du XIXe siècle, les trois évolutions les plus importantes ont été la régression structurelle des exportations de l'Asie des produits de haute qualité vers les produits primaires, la situation d'exportateur primaire des États-Unis et la division du travail entre Grande-Bretagne et France, entre exportations de produits industriels de qualité moyenne et exportations de produits de luxe et demi-luxe. Cette division internationale du travail marque encore fortement les échanges du XXe siècle. Au travers de cette étude sont recherchés les déterminants de la division internationale du travail, qui ne se comprend guère avec l'analyse économique standard d'inspiration ricardienne ou néoclassique. Des raisons complexes - provenant de la structure sociale des marchés des pays exportateurs, de leurs traditions de savoir-faire, des pratiques et des circuits commerciaux, des usages de paiement et de la structure des circuits des compensations internationales - expliquent que les actions individuelles des agents économiques convergent vers des configurations macroéconomiques qui ont leurs logiques propres.
Les techniques dans l'espace public
Authors: Hilaire-Pérez Liliane , Thébaud-Sorger Marie
Published: October 2008

Le but de cet article est d'interroger les transformations culturelles qui accompagnent la commercialisation des inventions, phénomène majeur de l'essor marchand et consumériste au XVIIIesiècle. Les stratégies commerciales des inventeurs sont fondées sur une médiatisation croissante, mêlant rhétoriques visuelles (démonstrations, spectacles, expositions) et recours à l'imprimé: annonces de presse, affiches, prospectus, modes d'emploi, livrets d'utilisation. L'information et le savoir techniques jouent un rôle clef dans la construction de marchés pour les inventions. Cette dimension a rarement été prise en compte dans l'histoire de la consommation et dans l'histoire des techniques. Pourtant, la littérature d'usage, qui postule l'autonomie et la capacité participative de l'acheteur comme argument de vente, exprime la montée en puissance des savoirs d'action, opératoires, prescriptifs, où priment le verbe et le geste, l'intention et le projet. Si la technologie des Lumières se déploie dans les traités et les dictionnaires, elle se manifeste aussi dans cette littérature éphémère, pratique et commerciale, source d'appropriations.
Le plan de sauvetage des scientifiques français
Authors: Dosso Diane
Published: October 2008

De 1940 à 1942, un certain nombre de scientifiques français se réfugie en Amérique avec leur famille. Ils font partie - souvent sans en avoir conscience - d'un plan de sauvetage organisé depuis New York par deux de leurs collègues, Henri Laugier et Louis Rapkine, avec l'aide financière et logistique de la fondation Rockefeller. La reconstitution des différentes étapes qui jalonnent le parcours du candidat à l'exil prouve que le gouvernement de Vichy ne fit pas obstacle, par principe, au départ temporaire de ses intellectuels de renom, même juifs. Quant aux États-Unis, ils favorisèrent l'accueil des seuls savants susceptibles d'enrichir durablement la vie intellectuelle américaine.
TRANSLATOR'S INTRODUCTION: STAGING BADIOU
Authors: Bosteels Bruno
Published: October 2008

Rhapsody for the Theatre: A Short Philosophical Treatise, first published in French in 1990, occupies a unique spot in Alain Badiou's oeuvre. Part theory and part theatre, or at least prototheatre, it certainly can be read alongside other books from the same period, especially Handbook of Inaesthetics and Metapolitics, devoted respectively to the truth procedures of art and politics that function as two of the four conditions of philosophy according to Badiou. Of the other two conditions, mathematics is treated in Number and Numbers and Briefings on Existence: A Short Treatise on Transitory Ontology, whereas love is the only truth procedure not to receive a book-length investigation. Even in the case of Badiou's treatment of love, a text such as “The Scene of the Two” resonates with the present text due to the importance given to the production of a “scene” for the amorous couple. In addition to opening up a fascinating dialogue with this theoretical treatment of the four conditions of philosophy, Rhapsody for the Theatre also and at the same time can serve as the ideal accompanying piece for Badiou's work as a playwright, most notably the Ahmed tetralogy that comprises Ahmed le subtil, Ahmed philosophe, Ahmed se fâche, and Les Citrouilles and that was staged in a quick creative sequence starting just four years after Rhapsody for the Theatre was published. In fact, one of the most intriguing aspects of this treatise is the way in which it moves between philosophy and theatre to the point of opening up a space of indiscernibility between the two.
Semantic versus Syntactic Cues in Listening Comprehension
Authors: Conrad Linda
Published: November 2008

Studies have shown that less fluent non-native readers cannot make full use of semantic-level cues. Non-natives direct proportionately more attention than natives to syntactic and graphophonic information. This study asked whether a similar difference would be found between native and non-native listeners. Three groups were tested: native English-speakers and advanced and intermediate non-natives. After hearing a text, subjects were given a 55-item cloze test. It was hypothesized that with a subject's increased proficiency in the language, processing would show progressively greater attention to semantic than to syntactic or phonological cues. The cloze test was scored using a diagnostic scoring procedure developed by Clarke and Burdell (1977). Results confirmed the hypothesis. Semantically acceptable responses increased progressively for intermediate, advanced, and native groups, while responses based on syntactic structure decreased.
Relativity in Connexion with Axial Rotation
Authors: Hargreaves R.
Published: November 2008

§ 1. My primary aim here is to give some account of relativity in connexion with axial rotation, and in particular to deal with the disk problem. The justification of the use of a special quadratic form for this purpose suggests the propriety of some introductory remarks of a more general character.
Three related quartic curves in four dimensions
Authors: Telling H. G.
Published: November 2008

1. It has been shown by Pieri, and independently by James, that the trisecant planes of a quartic curve in [4] which meet a line meet also another quartic curve intersecting the former in six points. James generalises the theorem and shows that trisecant planes of a quartic curve C, which meet a quartic curve C1 having six points in common with C, also meet another quartic curve C2, and that the relation between the three curves is symmetrical. The object of this note is to give a simple proof of this theorem and to discuss the representation by which this proof is effected. The method used is analogous to that of Pieri; an interesting differential method is adopted by C. Segre who shows that the foci of the first and second orders, of any linear system of ∞2 planes in [4] of which two planes pass through a point, determine a conic and five points respectively, in any plane of the system: the trisecant planes of C meeting C1 give a particular case of such a system.
Isolated singular points in the theory of algebraic surfaces
Authors: Babbage D. W.
Published: November 2008

If F(x0, x1, x2, x3) = 0 is the equation of a surface in space of three dimensions which has an ordinary isolated s-ple point O, then by means of the substitutions

where Φ0 = 0, Φ1 = 0, …, Φr = 0 are the equations of r + 1 linearly independent surfaces passing simply through O, F is transformed into a surface F′ in [r], on which to the point O of F there corresponds a simple curve γ. The points of γ arise from the points of F in the first neighbourhood of O, and in this simple case the genus of γ is ½ (s − 1) (s − 2). In the study of properties which are common to all members of an infinite family of birationally equivalent surfaces no distinction is made between O and γ, O being regarded as a curve which has become infinitesimal on the particular surface of the family in question.
Note on Eddy Current Losses in the Sheaths of Rectifier Cables
Authors: Carter F. W.
Published: November 2008

In previous communications to the Society the author has discussed the eddy current losses in the sheaths of cables supplying a polyphase alternating current system; and has given equations from which the loss could be computed in any case. The present communication deals with the particular case of the cables leading from the supply-transformers to the electrodes of a mercury vapour rectifier, and derives interest from the fact that the loss in the sheaths is found to be substantially independent of their nature.
A note on the calculation of the spacing of energy levels in a heavy nucleus
Authors: Sneddon I. N. , Touschek B. F.
Published: November 2008

It is known as a result of various experiments on slow neutrons (1) that a heavy nucleus possesses an enormous number of energy levels which are very closely spaced if the nucleus is highly excited. Strong theoretical reasons for the existence of this great number of levels were given by Bohr (2) and since then various attempts have been made to calculate the number of energy levels of a heavy nucleus. In the first of these, due to Bethe(3), it was assumed that the interaction between the nucleons was small so that the nucleus could be treated as a gas. The alternative assumption, that we may consider the interaction to be large in comparison with the kinetic energy of the nucleons, was proposed by Bohr and Kalckar(4). In the present note we assume as our model a nucleus consisting of neutrons and protons independent of one another; we then have a neutron-gas in equilibrium with a proton-gas, Fermi-Dirac statistics being applied to both.
On the interaction of colloidal particles V. nature of repulsion between particles in dilute sols
Authors: Levine S.
Published: November 2008

An extension is proposed to the theory of Verwey and Overbeek on the force between two colloidal particles in a dilute sol. The effect of the Coulomb interaction of the ions in the dispersion medium is considered. It is shown that this contributes an additional repulsion term to the mutual free energy of the two particles. This correction term behaves as an inverse power and is the predominant effect at large separations, although it is a second-order effect at small separations. For parallel plates, this power is the fourth, and for two spheres, the sixth. A tentative calculation shows that, at least for thin plates and low electrolyte concentrations, our new repulsion will outweigh the attractive London-van der Waals force considered by Verwey and Overbeek, and more recently by Casimir and Polder, when the plates are far apart.
A problem in dynamic plasticity: the enlargement of a circular hole in a flat sheet
Authors: Freiberger W.
Published: November 2008

The problem discussed in this paper is the enlargement of a circular hole in a flat sheet of which the material is in plastic flow under constant shear stress; inertia terms are taken into account in the equilibrium equations so as to permit the occurrence of high velocities.

The treatment is in some ways analogous to that of problems in one-dimensional compressible gas flow. The characteristic equations are seen to represent straight lines under certain initial conditions; this facilitates consideration of any mode of enlargement; in particular, uniform acceleration is illustrated by numerical calculations. There appears a circular shock-front, i.e. a discontinuity in thickness and velocity moving ahead of the hole. The initial conditions for the existence of this ‘simple wave' solution involve a singularity at the centre of the plate.

In general, the characteristic curves will not be straight lines and the equations are best solved step by step. Their characteristic form is well adapted to such a process; this is outlined for the interesting case of initial enlargement with uniform velocity followed by expansion under constant acceleration.

Curves illustrate some of the general results.
On the computation of oscillatory integrals
Authors: Luke Yudell L.
Published: November 2008

Computation of integrals of the typeis of frequent occurrence in applied problems. Here λ is real and i is the imaginary unit. Tables of the integrals are often required for a wide range of λ values, some of which may be quite large. Tabulation of the integrand for each λ, followed by ordinary methods of numerical integration, is slow and tedious because the number of points required increases with increasing λ. In this paper formulas are given so that oncef(y) is tabulated over the range of interest, the integral in question can be easily evaluated for any λ.
Whitehead products and vector-fields on spheres
Authors: James I. M.
Published: November 2008

In the theory of vector-spaces an ordered, ortho-normal set of r vectors is called an r-frame. Let Sn denote the unit sphere in euclidean (n+ 1)-space, where n ≥ 1. By an r-field on Sn is meant a continuous function which assigns to each point of Sn an r-frame in the tangent space at that point. If q < r we obtain a q-field from an r-field by suppressing the first r – q vectors of each r-frame. Certainly Sn admits a 0-field, and does not admit an (n+ 1)-field, since the tangent space is n-dimensional. An n-field on Sn is called a parallelism. Notice that an (n − 1)-field on Sn can always be extended to an n-field, since spheres are orientable. The problem is to determine the greatest value of r such that Sn admits an r-field.
Abstract Köthe Spaces. II
Authors: Fremlin D. H.
Published: November 2008

This paper is devoted to results concerning the connexion between the ‘abstract’ preK spaces of (l) and the ‘concrete’ Köthe spaces of (3). These results, though in part independent, are not truly original, being in particular known to the authors of (2); but as far as I am aware they have not appeared in print in quite the form they take here.
Contributions à l'étude des effets des extrémités dans un générateur à électrodes finies
Authors: DragoŞ Lazar
Published: November 2008

The paper studies the motion of an electro-conductive non-viscous incompressible fluid in a generator of rectangular section having finite electrodes and the rest of its walls being insulating. It is assumed that in the electrodes region a homogeneous magnetic field is applied, whose orientation is normal to the plane of the motion. If the induced magnetic field is neglected, the current function ψ(x, y) and the electrical potential ϕ(x, y) satisfy a system of equations with partial derivatives of the second order, with distributions. Since the system depends upon the parameter λ = RM RH a method of successive approximations is developed, which permits one to obtain the exact solution of the problem. In the last paragraph the results are extended to the case of a generator with N pairs of symmetrical electrodes.
Partitioning the plane into denumerably many sets without repeated distances
Authors: Davies Roy. O.
Published: November 2008

Ceder(1) proved (assuming the axiom of choice, as we do throughout this paper) that the Euclidean plane can be partitioned into ℵ0 sets none of which contains an equilateral triangle; indeed he proved that given any denumerable set of triangles, the plane can be partitioned into ℵ0 sets, none containing a triangle similar to one of the given triangles. Erdős and Kakutani(2) proved that the continuum hypothesis implies that the real line can be partitioned into ℵ0, rationally independent sete, and that the existence of such a partition implies the continuum hypothesis. Erdős asked (private communication) whether there is a partition of the plane into ℵ0 sets not containing an isosceles triangle, or more generally in which any four points determine six different distances. Assuming the continuum hypothesis, it will be shown here (Theorem 1) that a, partition of the latter kind does exist. (I communicated this result to Erdős and others some years ago, but subsequently noticed that the argument was incomplete.) Conversely (Theorem 2) the existence of such a partitition, even for the line, implies the continuum hypothesis. This strengthening of the converse half of the Erdős-Kakutani theorem is proved by what is essentially their method (actually in a rather simplified form).
Invariance relations in thermoelasticity with generalized variables
Authors: Hill R.
Published: November 2008

In the spirit of generalized coordinates in Lagrangian mechanics, the finite deformation of a material element is considered to be specified by arbitrary geometric variables, and the associated generalized stresses are generated by work conjugacy. The comparative quantitative influences of such coordinate choices are investigated for the main state variables in anisotropic thermoelasticity, namely the moduli, compliances, thermal coefficients of expansion, pressure coefficients, and specific heats. Transformation formulae are obtained to connect the respective values of the state variables for different choices. Special attention is given to the identification of coordinate-invariant magnitudes and relationships. The entire analysis is carried farther for coordinates in a class of tensor measures of finite strain; such measures are used widely in current theories of the mechanical response of solid materials, but apparently not yet in regard to thermal phenomena.
Radicals of semigroup rings of commutative semigroups
Authors: Okniński J. , Wauters P.
Published: November 2008

In this paper we determine radicals of semigroup rings R[S] where R is an associative, not necessarily commutative, ring and S is a commutative semigroup. We will restrict ourselves to the prime radical P, the Levitzki radical L and the Jacobson radical J. At the end we will also give a few comments on the Brown-McCoy radical U.
K-theory of real algebraic surfaces and threefolds
Authors: Bochnak J. , Kucharz W.
Published: November 2008

LetXbe an affine real algebraic variety, i.e., up to biregular isomorphism an algebraic subset of ℝn. (For definitions and notions of real algebraic geometry we refer the reader to the book [6].) Letdenote the ring of regular functions onX([6], chapter 3). (IfXis an algebraic subset of ℝnthenis comprised of all functions of the formf/g, whereg, f: X→ ℝ are polynomial functions withg−1(O) = Ø.) In this paper, assuming thatXis compact, non-singular, and that dimX≤ 3, we compute the Grothendieck groupof projective modules over(cf. Section 1), and the Grothendieck groupand the Witt groupof symplectic spaces over(cf. Section 2), in terms of the algebraic cohomology groupsandgenerated by the cohomology classes associated with the algebraic subvarieties ofX. We also relate the groupto the Grothendieck groupKO(X) of continuous real vector bundles overX, and the groupsandto the Grothendieck groupK(X)of continuous complex vector bundles overX.
Localization of seif-homotopy equivalences inducing the identity on homology
Authors: Maruyama Ken-Ichi
Published: November 2008

Let us denote the group of based homotopy classes of seif-homotopy equivalences of a space X by E(X). We consider E0(X), the subgroup of E(X) consisting of elements which induce the identity map on homology. Dror and Zabrodsky have shown that E0(X) and the subgroup E#(X) consisting of elements inducing the identity on homotopy are both nilpotent groups for finite-dimensional nilpotent spaces, or finite-dimensional spaces respectively ([4], theorem D, theorem A). The theory of localization for nilpotent groups has been developed by several authors (see [8]). The aim of this paper is to prove the following theorem. The corresponding result for E#(X) is obtained in [9], theorem 0·1.
Poincaré and Friedrichs inequalities in abstract Sobolev spaces II
Authors: Edmunds D. E. , Opic B. , Rákosník J.
Published: November 2008

This paper is a continuation of [4]; its aim is to extend the results of that paper to include abstract Sobolev spaces of higher order and even anisotropic spaces. Let Ω be a domain in ℝN, let X = X(Ω) and Y = Y(Ω) be Banach function spaces in the sense of Luxemburg (see [4] for details), and let W(X, Y) be the abstract Sobolev space consisting of all f ∈ X such that for each i ∈ {l, …, N} the distributional derivative belongs to Y; equipped with the norm

W(X, Y) is a Banach space. Given any weight function w on Ω, the triple [w, X, Y] is said to support the Poincaré inequality on Ω. if there is a positive constant K such that for all u ∈ W(X, Y)

the pair [X, Y] is said to support the Friedrichs inequality if there is a positive constant K such that for all u ∈ W0(X, Y) (the closure of in W(X, Y))
On the bifurcation of steady vortex rings from a Green function
Authors: Tadie
Published: November 2008

This paper is a supplement to [2]. There, solutions ψ., (μ) of certain free-boundary problems, depending on a small parameter μ, are related to the Green function G., (a(μ)) of a second-order, elliptic, partial differential equation defined on a bounded set Ω ⊂ ℝ2. The free boundary is the boundary of a set A(μ) ⊂ Ω that is unknown a priori and corresponds to the cross-section of a steady vortex ring or of a confined plasma in equilibrium, for example.
Quelques Remarques à Propos D'Une Note De G. H. Hardy: The Resultant of two Fourier Kernels (1)
Authors: Plancherel Michel
Published: November 2008

En prenant connaissance d'un mémoire récent de M. G. Doetsch(2), mon attention a été ramenée sur quelques remarques de nature élémentaire que la lecture de la note de M. Hardy, citée ci-dessus, m'avait suggérées et qui me paraissent apporter quelque clarté sur l'origine des résultats obtenus par ces auteurs relativement à la composition des noyaux de Fourier. Des remarques analogues sont contenues dans un article de M. Hermann Kober qui paraitra prochainement(3) et dont M. Hardy m'a obligeamment communiqué les épreuves. La voie que j'ai suivie diffère de celle de M. Kober; je l'expose brièvement ci-dessous.
Veränderungen in der Stresswahrnehmung und -bewältigung bei Jugendlichen mit Diabetes im Vergleich zu gesunden Jugendlichen
Authors: Seiffge-Krenke Inge , Knebel Achim
Published: October 2008

Zusammenfassung. Ziel dieser Studie war eine Reanalyse der Daten zu Stress und Coping von Jugendlichen mit Typ 1 Diabetes (n = 91) im Vergleich zu gesunden (n = 107) im Längsschnitt (Alter bei Ersterhebung: M = 13.9, SD = 1.35). Über vier Erhebungswellen wurde Stress und Coping erhoben und mittels verschiedener Modellierungen mit latenten Wachstumsmodellen analysiert. Neben der Abklärung, ob der Gesundheitsstatus eher eine Moderator- oder eine Mediatorvariable in Bezug auf Stress und Coping in der Adoleszenz darstellt, wurden die Auswirkungen des Geschlechts und des Alters zu Studienbeginn untersucht. Weitere Analysen gingen dem Einfluss der Qualität der glykämischen Kontrolle bei Jugendlichen mit Typ 1 Diabetes nach. Neben einem Rückgang der Stressbelastung fanden sich Zugewinne im Copingverhalten (aktives und internales Coping), die für Jugendliche mit Typ 1 Diabetes weniger deutlich ausfielen. Diabetiker mit guter glykämischer Kontrolle zeigten die stärksten Abnahmen in der Stressbelastung und die stärksten Zunahmen in den funktionalen Bewältigungsstilen, was die Bedeutung einer guten Stoffwechselkontrolle aus medizinischer und psychologischer Sicht unterstreicht.
Psychologische Operationsvorbereitung, Stressbewältigung und perioperativer Status
Authors: Krohne Heinz Walter , El-Giamal Muna
Published: October 2008

Zusammenfassung. In Studien zum Einfluss einer psychologischen Operationsvorbereitung auf den postoperativen Anpassungsstatus von Patienten wurde bislang einer möglichen Interaktion der Art der Vorbereitung mit Persönlichkeitsmerkmalen des Patienten nur wenig Beachtung geschenkt. Ziel der vorliegenden Arbeit ist die Analyse von Wechselwirkungen zwischen unterschiedlichen Formen der psychologischen Operationsvorbereitung und bestimmten Merkmalen des Patienten im Hinblick auf subjektive und objektive Indikatoren der perioperativen Patientenbelastung. In einer Untersuchung an 97 chirurgischen Patienten (Nasennebenhöhlen- oder Septumoperationen; 66 Männer und 31 Frauen) konnte nachgewiesen werden, dass die beiden Vorbereitungsprogramme „Information” und „Entspannung/Ablenkung” zusammen mit dem Geschlecht der Patienten sowie den Persönlichkeitsmerkmalen vigilante und kognitiv vermeidende Angstbewältigung eine Wechselwirkung auf perioperative Belastungsmerkmale (Angst, Genesungsfortschritt, Schmerzbelastung) ausübten. Die Ergebnisse werden auf dem Hintergrund des Modells der Bewältigungsmodi ( Krohne, 2003 ) diskutiert.
Zum Zusammenhang von berichteter Nahrungsaufnahme und ADHS-Symptomen bei Jungen
Authors: Hubel Ralph , Jaß Jana , Marcus Alexander , Läßle Reinhold G.
Published: October 2008

Zusammenfassung. ADHS geht mit einem erhöhten Gewichtsstatus sowie einem erhöhten Energieverbrauch einher. ADHS-Symptome sollten daher auch mit einer erhöhten Energieaufnahme assoziiert sein. Untersucht wurde, ob sich Zusammenhänge zwischen ADHS-Symptomen sowie der mittels Ernährungsprotokollen berichteten aufgenommenen Energiemenge bei Kindern und Jugendlichen nachweisen lassen. Es wurden 75 Jungen im Alter von 8–14 Jahren untersucht. Aufmerksamkeitsprobleme gingen mit einer geringeren absoluten sowie einer geringeren am Grundumsatz relativierten Energieaufnahme, Hyperaktivität sowohl mit einer höheren absoluten als auch einer höheren am Grundumsatz relativierten Energieaufnahme einher. Probanden mit Aufmerksamkeitsproblemen tendieren möglicherweise vermehrt zu einer Unterschätzung der aufgenommenen Energiemenge als solche ohne Aufmerksamkeitsprobleme.
Coherent surface‐subsurface fingerprint of the Atlantic meridional overturning circulation
Authors: Zhang Rong
Published: October 2008

Satellite altimeter data shows a weakening of the North Atlantic subpolar gyre during the 1990s, which is thought as an indicator of a slowdown of the Atlantic meridional overturning circulation (AMOC). However, whether the recent slowing subpolar gyre is a decadal variation or a long‐term trend remains unclear. Here I show that altimeter data is highly correlated with instrumental subsurface ocean temperature data in the North Atlantic, and both show opposite signs between the subpolar gyre and the Gulf Stream path. Such a dipole pattern is a distinctive fingerprint of AMOC variability, as shown for the first time by a 1000‐year coupled ocean‐atmosphere model simulation. The results suggest that, contrary to previous interpretations, the recent slowdown of the subpolar gyre is a part of a multidecadal variation and suggests a strengthening of the AMOC. The ongoing satellite and subsurface temperature measurements could be used to monitor future AMOC variations sensitively.
Effect of Vowel Identity and Onset Asynchrony on Concurrent Vowel Identification
Authors: Hedrick Mark S. , Madix Steven G.
Published: October 2008

Purpose

The purpose of the current study was to determine the effects of vowel identity and temporal onset asynchrony on identification of vowels overlapped in time.

Method

Fourteen listeners with normal hearing, with a mean age of 24 years, participated. The listeners were asked to identify both of a pair of 200-ms vowels (referred to as
double vowels
) presented either simultaneously or with a temporal asynchrony ranging from 25 ms to 150 ms in 25-ms steps. The stimuli were synthetic steady-state vowels /i æ ɑ u ɝ/ arranged in seven combinations: /u i/, /æ ɑ/, /ɝ ɑ/, /ɝ æ/, /æ i/, /ɝ i/, and /ɝ u/.

Results

Listeners' responses revealed that one vowel of a pair was identified correctly more often than the other vowel (known as
vowel dominance
). Vowel dominance effects were seen for 6 of the 7 vowel pairs, and there was improvement of vowel identification with increasing temporal separation between vowels for 5 of the 7 pairs. Vowel pairs with the vowel /ɝ/ consistently yielded improved identification with increases in temporal asynchrony.

Discussion

Peripheral masking cannot explain the patterns of results of this study. A more parsimonious explanation may be perceptual anchoring.
Phonological Constraints on Children’s Production of English Third Person Singular –
s
Authors: Yung Song Jae , Sundara Megha , Demuth Katherine
Published: October 2008

Purpose

Children variably produce grammatical morphemes at early stages of development, often omitting inflectional morphemes in obligatory contexts. This has typically been attributed to immature syntactic or semantic representations. In this study, the authors investigated the hypothesis that children’s variable production of the 3rd person singular morpheme –
s
interacts with the phonological complexity of the verb stem to which it is attached.

Method

To explore this possibility, the authors examined longitudinal data from the spontaneous speech of 6 English-speaking children between ages 1;3 and 3;6 (years;months) and elicited imitations from a cross-sectional study of 23 two-year-olds (mean age of 2;2).

Results

The results showed that children produced third person singular morphemes more accurately in phonologically simple coda contexts (e.g.,

see
s

) as compared with complex coda contexts (e.g.,

nee
ds

). In addition, children produced
–s
more accurately in utterance-final position as compared with utterance-medial position.

Conclusions

The results provide strong support for the role of phonological complexity in explaining some of the variability in children’s production of third person singular –
s
. This finding suggests that future research will need to consider multiple factors, including phonological and positional effects, in constructing a comprehensive developmental theory of both grammatical competence and processes of speech planning and production.
Discrimination of Speech Sounds Based Upon Temporal Envelope Versus Fine Structure Cues in 5- to 7-Year-Old Children
Authors: Bertoncini Josiane , Serniclaes Willy , Lorenzi Christian
Published: October 2008

Purpose

To investigate the capacity of young children and adults with normal hearing to discriminate speech on the basis of either relatively slow (temporal envelope, E) or fast (temporal fine structure, TFS) auditory cues.

Method

Vowel-consonant-vowel nonsense disyllables were processed to preserve either the E or the TFS information in 16 adjacent frequency bands. The band signals were then recombined and resulting stimuli were presented for discrimination to adults or 5-, 6-, and 7-year-old children using an odd-ball paradigm. Discrimination scores (d′) and response latencies were measured in each listener. No training was given to listeners.

Results

Overall, discrimination scores were high (d′≥1) in all speech-processing conditions, and did not differ across age groups. Overall, and irrespective of age, greater discrimination scores and shorter response latencies were observed for E speech than for TFS speech.

Conclusions

These results suggest that normal-hearing children are able to encode and use E and TFS speech cues at adult levels by the age of 5 years. TFS- and E-coded speech stimuli might therefore prove to be a useful tool for the investigation of the developmental time course of speech perception, and for the early diagnosis of peripheral and central auditory processing disorders.
Factor Structure and Reliability of the Dutch Version of Seven Scales of the Communication Profile for the Hearing Impaired (CPHI)
Authors: Mokkink Lidwine B. , Knol Dirk L. , Zekveld Adriana A. , Goverts S. Theo , Kramer Sophia E.
Published: October 2008

Purpose

Seven scales of the Communication Profile for the Hearing Impaired (CPHI; M. E. Demorest & S. A. Erdman, 1987) were translated into Dutch: Maladaptive Behavior, Verbal Strategies, and Nonverbal Strategies (within the area of Communication Strategies) and Self-Acceptance, Acceptance of Loss, Stress, and Withdrawal (within the area of Personal Adjustment).

Method

This cross-sectional study evaluated the factor structure, internal consistency, test–retest reliability, and measurement error of the Dutch CPHI scales. In all, 399 adults with impaired hearing participated, and data on a subgroup of 40 patients were included in the test–retest analyses. The participants completed the questionnaire before routine clinical care or at home. Demographic data and data on pure-tone hearing thresholds were also collected.

Results

Based on item factor analyses, we omitted 5 items, moved 3 items to different scales, and combined the Stress and Withdrawal scales. The resulting 6 scales, containing 52 items, showed good internal consistency (alphas between 0.81 and 0.94), good test–retest reliability (intraclass correlation coefficients between 0.78 and 0.86), and small standard error of measurement (between 0.28 and 0.46).

Conclusions

The suggested revisions of the Dutch CPHI scales will increase their interpretability. Further research is needed to evaluate their usefulness for monitoring patients and in longitudinal studies by determining their responsiveness and minimal important change values.
Spectral Tilt Change in Stop Consonant Perception by Listeners With Hearing Impairment
Authors: Alexander Joshua M. , Kluender Keith R.
Published: October 2008

Purpose

To evaluate how perceptual importance of spectral tilt is altered when formant information is degraded by sensorineural hearing loss.

Method

Eighteen listeners with mild to moderate hearing impairment (HI listeners) and 20–23 listeners with normal hearing (NH listeners) identified synthesized stimuli that varied in second formant (F
2
) frequency and spectral tilt. Experiments 1 and 2 examined utterance-initial stops (/ba/ and /da/), and Experiments 3 and 4 examined medial stops (/aba/ and /ada/). Spectral tilt was manipulated at either consonant onset (Experiments 1 and 3), vowels (Experiments 2 and 4), or both (Experiment 5).

Results

Regression analyses revealed that HI listeners weighted F
2
substantially less than NH listeners. There was no difference in absolute tilt weights between groups. However, HI listeners emphasized tilt as much as F
2
for medial stops. NH listeners weighted tilt primarily when F
2
was ambiguous, whereas HI listeners weighted tilt significantly more than NH listeners on unambiguous F
2
endpoints.

Conclusions

Attenuating changes in spectral tilt can be as deleterious as taking away F
2
information for HI listeners. Recordings through a wide dynamic range compression hearing aid show compromised changes in spectral tilt, compressed in range by up to 50%.
Test–Retest Reliability of Low-Level Evoked Distortion Product Otoacoustic Emissions
Authors: Stuart Andrew , Passmore Amy L. , Culbertson Deborah S. , Jones Sherri M.
Published: October 2008

Purpose

The purpose of this study was to examine test–retest reliability of low-level evoked distortion product otoacoustic emissions (DPOAEs) as a function of L
1
, L
2
level; f
2
frequency; and test condition. A predictive relationship between these variables and the presence/absence of DPOAE responses was also examined.

Method

Sixteen normal-hearing young adults participated. DPOAEs were evoked to 12 tones with f
2
frequencies ranging from 1500 Hz to 7546 Hz at 4 L
2
levels between 45 dB SPL and 30 dB SPL. Four test conditions were employed: (a) initial test, (b) retest without probe removal, (c) retest with probe reinsertion, and (d) retest with probe reinsertion by a second tester.

Results

L
1
, L
2
level and f
2
frequency were statistically significant (
p
< .0001) predictors of a DPOAE response (i.e., the presence of a DPOAE response was more likely to be observed at higher L
1
, L
2
levels and lower f
2
frequencies regardless of test condition). DPOAE levels were significantly affected by L
1
, L
2
level and f
2
frequency (
p
< .0001) but not by test condition. Intra- and intertester test–retest differences were not significantly different.

Conclusions

The prevalence of missing responses coupled with large intersubject variability and intrasubject test–retest variability are a detriment to the clinical utility of DPOAEs evoked with low-level stimuli.
A framework for predicting global silicate weathering and CO
2
drawdown rates over geologic time-scales
Authors: Hilley George E. , Porder Stephen
Published: October 2008

Global silicate weathering drives long-time-scale fluctuations in atmospheric CO
2
. While tectonics, climate, and rock-type influence silicate weathering, it is unclear how these factors combine to drive global rates. Here, we explore whether local erosion rates, GCM-derived dust fluxes, temperature, and water balance can capture global variation in silicate weathering. Our spatially explicit approach predicts 1.9–4.6 × 10
13
mols of Si weathered globally per year, within a factor of 4–10 of estimates of global silicate fluxes derived from riverine measurements. Similarly, our watershed-based estimates are within a factor of 4–18 (mean of 5.3) of the silica fluxes measured in the world's ten largest rivers. Eighty percent of total global silicate weathering product traveling as dissolved load occurs within a narrow range (0.01–0.5 mm/year) of erosion rates. Assuming each mol of Mg or Ca reacts with 1 mol of CO
2
, 1.5–3.3 × 10
8
tons/year of CO
2
is consumed by silicate weathering, consistent with previously published estimates. Approximately 50% of this drawdown occurs in the world's active mountain belts, emphasizing the importance of tectonic regulation of global climate over geologic timescales.
Mean mass-specific metabolic rates are strikingly similar across life's major domains: Evidence for life's metabolic optimum
Authors: Makarieva Anastassia M. , Gorshkov Victor G. , Li Bai-Lian , Chown Steven L. , Reich Peter B. , Gavrilov Valery M.
Published: October 2008

A fundamental but unanswered biological question asks how much energy, on average, Earth's different life forms spend per unit mass per unit time to remain alive. Here, using the largest database to date, for 3,006 species that includes most of the range of biological diversity on the planet—from bacteria to elephants, and algae to sapling trees—we show that metabolism displays a striking degree of homeostasis across all of life. We demonstrate that, despite the enormous biochemical, physiological, and ecological differences between the surveyed species that vary over 1020-fold in body mass, mean metabolic rates of major taxonomic groups displayed at physiological rest converge on a narrow range from 0.3 to 9 W kg−1. This 30-fold variation among life's disparate forms represents a remarkably small range compared with the 4,000- to 65,000-fold difference between the mean metabolic rates of the smallest and largest organisms that would be observed if life as a whole conformed to universal quarter-power or third-power allometric scaling laws. The observed broad convergence on a narrow range of basal metabolic rates suggests that organismal designs that fit in this physiological window have been favored by natural selection across all of life's major kingdoms, and that this range might therefore be considered as optimal for living matter as a whole.