bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arbuscular mycorrhizal colonization and spore density across different land‐use types in a hot and arid ecosystem, Southwest China
Authors: Li Ling‐Fei , Zhang Yan , Zhao Zhi‐Wei 
Published: May 2007

AbstractWe investigated the arbuscular mycorrhizal (AM) colonization and spore density in cropped land, fallow land, and an undisturbed savanna ecosystem under hot and arid climatic conditions in a valley of southwest China. Plants surveyed in the three land‐use types showed heavy arbuscular mycorrhizal colonization, indicating a high mycorrhizal dependency of plants in this environment. One‐way analysis of variance (ANOVA) showed that the colonization of different AM structures and the spore density varied greatly among plant species both within and between different land‐use types. The AM colonization and spore density were higher in undisturbed than in fallow or cropped land. No significant correlation between AM colonization and spore density was observed when land‐use types were either considered separately or together. Cluster analysis based on the similarity in AM status with respect to both colonization and spore density showed similarities between fallow land and the undisturbed savanna. The results indicate that continuous cropping reduces AM colonization and spore density. These parameters appear to nearly fully recover when the land has been left to fallow for 4 years.
Polyphosphate‐fertilizer solution stability with time, temperature, and pH
Authors: McBeath Therese M. , Lombi Enzo , McLaughlin Michael J. , Bünemann Else K. 
Published: May 2007

AbstractAmmonium polyphosphate fertilizers are gaining popularity in agricultural industry due to ease of application and yield benefits in calcareous soils. In this study, the effects of temperature, pH, and time on the stability of ammonium polyphosphate–fertilizer solution simulating a range of storage conditions were evaluated. Ion chromatography was used for the speciation of orthophosphate, pyrophosphate, and tripolyphosphate in the polyphosphate‐fertilizer solution over time. Polyphosphate solutions were very stable when the pH was maintained close to neutral (pH 6.4) and the temperature was less than 25°C. In contrast, at the lowest pH (2.3) and highest temperature (50°C) almost all tripolyphosphate and 96% of pyrophosphate was hydrolyzed after 28 d. The hydrolysis rate constant for tripolyphosphate at 50°C was calculated to be 9.2 × 10–7 s–1 and the half‐life 20 d. At 25°C, the half‐life of tripolyphosphate was 34 d at pH 2.3 and 174 d at pH 5.4. The activation energy at pH 2.3 was 12.7 kJ mol–1. The results demonstrate that increasing temperature and decreasing pH have a deleterious effect on the stability of condensed P species in polyphosphate fertilizer. The effect of acidification on polyphosphate‐fertilizer composition requires consideration when formulating mixed ammonium polyphosphate blends with acids and trace elements for application in the field.
Application of feedback‐controlled pulse shaping for control of CARS spectra: the role of phase and amplitude modulation
Authors: Konradi J. , Scaria A. , Namboodiri V. , Materny A. 
Published: May 2007

AbstractFemtosecond time‐resolved coherent anti‐Stokes Raman scattering (fs‐CARS) results in spectra that, as a function of the probe delay time, yield information about the dynamics of the coherently excited vibrational modes. A change of the shape of the exciting laser pulses has a dramatic influence on the spectral response. A feedback‐controlled optimization of specific modes making use of phase and amplitude modulation of the Stokes laser pulse is applied to selectively influence the anti‐Stokes signal spectrum. The role of phase and amplitude changes of the frequency components of the ultrashort pulse is analyzed. It can be demonstrated that the optimization process is clearly dominated by the effect of timing of the dispersed pulse segments. The modulation of the spectral amplitudes has only a small influence on the mode ratios. We conclude that mode focusing in time domain CARS spectroscopy can be achieved only by correctly setting the phases of the spectral pulse components (here demonstrated for the Stokes laser). Copyright © 2007 John Wiley & Sons, Ltd.
Water‐Based Polyurethane Filled with Multi‐Walled Carbon Nanotubes Prepared by a Colloidal‐Physics Method▪Author: This manuscript has been thoroughly edited. Please read the proofs carefully to ensure that no unintentional shift in meaning has been introduced.▪
Authors: Cai Dongyu , Song Mo 
Published: May 2007

AbstractMWCNT/water‐based PU composites were synthesized by means of a colloidal‐physics method. The effect of MWCNT addition on the electrical and thermal properties of the composites and the effect of NaCl addition on film formation of the PU latexes were investigated. The electrical conductivity of the water‐based PU was improved by more than four orders of magnitude, but remained still four orders of magnitude lower than that of the MWCNTs. The percolation threshold was found to be at 0.5 wt.‐% MWCNT. The thermal conductivity of the composites was improved by ≈86% at 7 wt.‐% MWCNT. MWCNT/PU dispersions displayed stronger shear thinning than pure PU dispersions.magnified image
Characterization of Polyaniline Nanotubes Formed in the Presence of Amino Acids
Authors: Zhang Lijuan , Peng Hui , Zujovic Zoran D. , Kilmartin Paul A. , Travas‐Sejdic Jadranka 
Published: May 2007

AbstractSelf‐assembled nanotubular structures of polyaniline were chemically synthesized from solutions containing different amino acids with the addition of ammonium persulfate as the oxidant. The materials were characterized by SEM and a range of spectroscopic methods. Spectroscopic characterizations revealed that the synthesized materials had many features typical of chemically synthesized PANI. Some additional features were also found and have been ascribed to non‐conducting material formed in the initial stages of the reaction at a higher solution pH. However, UV‐vis and 13C NMR spectra point toward a conductive material as the final product of the reaction. Cyclic voltammetry results also indicate an electroactive final product that closely resembles regular PANI in its electrochemical characteristics.magnified image
EPR Identification of Zr(III) Complexes Formed upon Interaction of (2‐PhInd)2ZrCl2 and rac‐Me2Si(1‐Ind)2ZrCl2 with MAO and MMAO
Authors: Lyakin Oleg Y. , Bryliakov Konstantin P. , Panchenko Valentina N. , Semikolenova Nina V. , Zakharov Vladimir A. , Talsi Evgenii P. 
Published: May 2007

AbstractReactions of 1 and 2 with MAO and MMAO were monitored by EPR. It was found that MMAO is a stronger reducing agent than MAO. 1 is more prone to reduction than 2. The reduction of ZrIV to ZrIII seems to be the essential pathway of some zirconocene catalysts' deactivation. ZrIII species with the following proposed structures can be identified in the 1/MMAO system: (2‐PhInd)2ZrIII(iBu), (2‐PhInd)2ZrIII(µ‐Cl)2AliBu2, (2‐PhInd)2ZrIII(µ‐Cl)(iBu)AliBu2, and [(2‐PhInd)2ZrIII]+[Me‐MAO]−. The degree of reduction of ZrIV species determined by EPR in the catalytic system 2/MMAO can be masked by the formation of diamagnetic ZrIII/ZrIII dimers. Addition of monomers to the 2/MAO system promotes reduction ot the zirconium species.magnified image
RECONSTRUCTION OF BINARY RELATIONS FROM THEIR RESTRICTIONS OF CARDINALITY 2, 3, 4 and (n ‐ 1) I
Authors: Lopez Gérard , Rauzy Claire 
Published: May 2007

AbstractWe prove that any binary relation with underlying set (base) E with cardinality n > 6 is reconstructible from its restrictions of cardinality 2, 3, 4 and (n ‐ 1). In part I we characterize relations R and R' on the same base E such that R/X and R'/X are isomorphic for every subset X of E with cardinality 2, 3, 4. In part II we shall prove that R and R' are isomorphic as soon as n > 6 when R/X and R/X' are isomorphic for every subset X of E with cardinality 2, 3, 4 and (n ‐ 1).
LEVELS OF IMPLICATION AND TYPE FREE THEORIES OF CLASSIFICATIONS WITH APPROXIMATION OPERATOR
Authors: Cantini Andrea 
Published: May 2007

AbstractWe investigate a theory of Frege structures extended by the Myhill‐Flagg hierarchy of implications. We study its relation to a property theory with an approximation operator and we give a proof theoretical analysis of the basic system involved. MSC: 03F35, 03D60.
THE DECISION PROBLEM FOR RESTRICTED UNIVERSAL QUANTIFICATION IN SET THEORY AND THE AXIOM OF FOUNDATION
Authors: Parlamento Franco , Policriti Alberto 
Published: May 2007

AbstractThe still unsettled decision problem for the restricted purely universal formulae ((∀)0‐formulae) of the first order set‐theoretic language based over =, ∈ is discussed in relation with the adoption or rejection of the axiom of foundation. Assuming the axiom of foundation, the related finite set‐satisfiability problem for the very significant subclass of the (∀)0‐formulae consisting of the formulae involving only nested variables of level 1 is proved to be semidecidable on the ground of a reflection property over the hereditarily finite sets, and various extensions of this result are obtained. When variables are restricted to range only over sets, in universes with infinitely many urelements the set‐satisfiability problem is shown to be solvable provided the axiom of foundation is assumed; if it is not, then the decidability of a related derivability problem still holds. That, in turn, suggests the alternative adoption of an antifoundation axiom under which the set‐satisfiability problem is also solvable (of course with different answers). Turning to set theory without urelements, assuming a form of Boffa's antifoundation axiom, the complement of the set‐satisfiability problem for the full class of Δ0‐formulae is shown to be semidecidable; a result that is known not to hold, for the set‐satisfiability problem itself, even for a very restricted subclass of the Δ0‐formulae.
ON THE ITERATED ω‐RULE
Authors: Michalski Grzegorz 
Published: May 2007

AbstractLet Γn(φ) be a formula of LPA (PA = Peano Arithmetic) meaning “there is a proof of φ from PA‐axioms, in which ω‐rule is iterated no more than n times”. We examine relations over pairs of natural numbers of the kind.(n, k) ≦H (n', k') iff PA + RFNn' (Hk') ⊩ RFNn (Hk).Where H denotes one of the hierarchies ∑ or Π and RFNn(C) is the scheme of the reflection principle for Γn restricted to formulas from the class C(Γn(φ) implies “φ is true”, for every φ ∈ C). Our main result is that.(n, k) ≦H (n', k') if n ≦ n' and k ≦ max (k', 2n' + 1).
ANEW RELATION‐COMBINING THEOREM AND ITS APPLICATION
Authors: Sun Zhi‐Wei 
Published: May 2007

AbstractLet ∃n denote the set of all formulas ∃x1…∃xn[P(x1, …,xn) = 0], where P is a polynomial with integer coefficients. We prove a new relation‐combining theorem from which it follows that if ∃n is undecidable over N, then ∃2n+2 is undecidable over Z.
ANALYTIC COMPLETENESS THEOREM FOR ABSOLUTELY CONTINUOUS BIPROBABILITY MODELS
Authors: Đorđević Radosav S. 
Published: May 2007

AbstractHoover [2] proved a completeness theorem for the logic L(∫)𝒜. The aim of this paper is to prove a similar completeness theorem with respect to product measurable biprobability models for a logic L(∫1, ∫2) with two integral operators. We prove: If T is a ∑1 definable theory on 𝒜 (a countable admissible set and ω ∈) and consistent with the axioms of L(∫1, ∫2), then there is an analytic absolutely continuous biprobability model in which every sentence in T is satified.
UNIVERSAL FUNCTIONS IN PARTIAL STRUCTURES
Authors: Negri Maurizio 
Published: May 2007

AbstractIn this work we show that every structure 𝒜 can be expanded to a partial structure 𝒜* with universal functions for the class of polynomials on 𝒜*. We can embed 𝒜* monomorphically in a total structure 𝒜º that preserves universal functions of 𝒜* and that is universal among such structures, i.e. 𝒜º can be homomorphically embedded in every total structure that preserves universal functions of 𝒜*. Universal functions are the starting point for developing recursion theoretic tools in an 𝒜* that satisfies some simple additional conditions.
THE AMBIGUOUS TYPE THEORY IS HEREDITARILY UNDECIDABLE
Authors: Kuzichev Andrey A. 
Published: May 2007

AbstractThe ambiguous type theory ATT is introduced in [1] in order to obtain a new proof of Specker's theorem on typical ambiguity [3]. In the present paper we imbed the recursively undecidable theory TR of a single transitive‐reflexive relation in an arbitrary stratified theory T such that T ⫅ ATT and so reduce the problem of derivability in TR to the same problem for T. From this it follows that ATT is hereditarily undecidable, i.e. ATT has no decidable subtheories.
ON THE INCOMPLETENESS OF A DESCENDING CHAIN OF EXTENSIONS OF IMPLICATIONAL S5
Authors: Ulrich Dolph 
Published: May 2007

AbstractC5.ω is obtained by adding, schematically, to the strict‐implicational fragment C5 of S5 the axiom ((p → q) → (q → p)) → (q → p). This paper presents a fully general proof that neither C5.ω nor any of a descending chain of its extensions is complete with respect to any class of frames, correcting the garbled details of a version skeched in an earlier paper (same Zeitschrift 31 (1985), 201‐208).
ON NON‐DETERMINED EHRENFEUCHT‐FRAÏSSÉ GAMES AND UNSTABLE THEORIES
Authors: Hyttinen Tapani , Hyttinen T. 
Published: May 2007

AbstractIn this paper we prove under some set theoretical assumptions that if T is a countable unstable theory then there is a pair of models of T such that Ehrenfeucht‐Fraïssé games between these models of large variety of lengths are non‐determined.
ON SOME INTERPRETATIONS OF CLASSICAL LOGIC
Authors: Boričić Branislav R. , Boričić B. R. 
Published: May 2007

AbstractIn distinction from the well‐known double‐negation embeddings of the classical logic we consider some variants of single‐negation embeddings and describe some classes of superintuitionistic first‐order predicate logics in which the classical first‐order calculus is interpretable in such a way. Also we find the minimal extensions of Heyting's logic in which the classical predicate logic can be embedded by means of these translations.
A FORMALISM FOR SOME CLASS OF FORCING NOTIONS
Authors: Koszmider Piotr , Koszmider P. 
Published: May 2007

AbstractWe introduce a class of forcing notions, called forcing notions of type S, which contains among other Sacks forcing, Prikry‐Silver forcing and their iterations and products with countable supports. We construct and investigate some formalism suitable for this forcing notions, which allows all standard tricks for iterations or products with countable supports of Sacks forcing. On the other hand it does not involve internal combinatorial structure of conditions of iterations or products. We prove that the class of forcing notions of type S is closed under products and certain iterations with countable supports.
INTERDEFINABILITY OF LAMBEKIAN FUNCTORS
Authors: Zielonka Wojciech , Zielonka W. 
Published: May 2007

AbstractSeveral Gentzen‐style (sequential) syntactic type calculi with product(s) are considered. They form a hierarchy in such a way that one calculus results from another by imposing a new condition (expressed in terms of “structural rules”) upon the sequent‐forming operation. It turns out that, at some steps of this process, two different functors collapse to a single one. For the remaining stages of the hierarchy, analogues of Wajsbergs's theorem on non‐mutual‐definability are proved.
COMPACTNESS, THE LÖWENHEIM‐SKOLEM PROPERTY AND THE DIRECT PRODUCT OF LATTICES OF TRUTH VALUES
Authors: Ying Mingsheng , Ying Mingsheng 
Published: May 2007

AbstractWe show that compactness is preserved by arbitrary direct products of lattices of truth values and that the Löwenheim‐Skolem property is preserved by finite direct products of lattices of truth values.
ORDINAL NUMBERS IN ARITHMETIC PROGRESSION
Authors: Bagemihl Frederick , Bagemihl F. 
Published: May 2007

AbstractThe class of all ordinal numbers can be partitioned into two subclasses in such a way that neither subclass contains an arithmetic progression of order type ω, where an arithmetic progression of order type τ means an increasing sequence of ordinal numbers (ß + δγ)γ<γ<>r, δ ≠ 0.
TWO TOPOLOGICAL EQUIVALENTS OF THE AXIOM OF CHOICE
Authors: Schechter Eric , Schechter E. 
Published: May 2007

AbstractWe show that the Axiom of Choice is equivalent to each of the following statements: (i) A product of closures of subsets of topological spaces is equal to the closure of their product (in the product topology); (ii) A product of complete uniform spaces is complete.
EIN NEUER BEWEIS UND EINE VERSCHÄRFUNG FÜR DEN REDUKTIONSTYP ∀∃∀∞(0, 1) MIT EINER ANWENDUNG AUF DIE SPEKTRALE DARSTELLUNG VON PRÄDIKATEN
Authors: Deutsch Michael , Deutsch M. 
Published: May 2007

AbstractA simultaneous semantical and syntactical reduction is given for the satisfiability respectively finite satisfiability of first order formulas. We choose ∀∃∀∞(0, 1) as conservative reduction class and allow only formulas out of ∀∃∀∞(0, 1) having a simple set theoretical model if they are satisfiable at all. With the same method we get a spectral representation of any ϱ‐ary enumerable respectively coenumerable predicate by a formula out of ∀∃∀∞(ϱ, 1).
An Interpretation of the Zermelo‐Fraenkel Set Theory and the Kelley‐Morse Set Theory in a Positive Theory
Authors: Esser Olivier 
Published: May 2007

AbstractAn interesting positive theory is the GPK theory. The models of this theory include all hyperuniverses (see [5] for a definition of these ones). Here we add a form of the axiom of infinity and a new scheme to obtain GPK∞+. We show that in these conditions, we can interprete the Kelley‐Morse theory (KM) in GPK∞+ (Theorem 3.7). This needs a preliminary property which give an interpretation of the Zermelo‐Fraenkel set theory (ZF) in GPK∞+. We also see what happens in the original GPK theory. Before doing this, we first need to study the basic properties of the theory. This is done in the first two sections.
Non‐Complementedness and Non‐Distributivity of Kleene Degrees
Authors: Muraki Hisato 
Published: May 2007

AbstractIn this note, we study the complementedness and the distributivity of upper semilattices of Kleene degrees assuming V = L. K denotes the upper semilattice of all Kleene degrees. We prove that if V = L, then some sub upper semilattices of K are non‐complemented and some are non‐distributive.
On a Spector Ultrapower for the Solovay Model
Authors: Kanovei Vladimir , van Lambalgen Michiel 
Published: May 2007

AbstractWe prove that a Spector‐like ultrapower extension 𝔑 of a countable Solovay model 𝔐 (where all sets of reals are Lebesgue measurable) is equal to the set of all sets constructible from reals in a generic extension 𝔐[a], where a is a random real over 𝔐. The proof involves the Solovay almost everywhere uniformization technique.
Rudimentary Languages and Second‐Order Logic
Authors: More Malika , Olive Frédéric 
Published: May 2007

AbstractThe aim of this paper is to point out the equivalence between three notions respectively issued from recursion theory, computational complexity and finite model theory. One the one hand, the rudimentary languages are known to be characterized by the linear hierarchy. On the other hand, this complexity class can be proved to correspond to monadic second‐order logic with addition. Our viewpoint sheds some new light on the close connection between these domains: We bring together the two extremal notions by providing a direct logical characterization of rudimentary languages and a representation result of second‐order logic into these languages. We use natural arithmetical tools, and our proofs contain no ingredient from computational complexity.
Riesz basis and stabilization for the flexible structure of a symmetric tree‐shaped beam network
Authors: Wang Jun‐Min , Guo Bao‐Zhu 
Published: May 2007

AbstractThe stabilization of a symmetric tree‐shaped network of Euler–Bernoulli beams described by a system of partial differential equations is considered. The boundary controllers are designed based on passivity principle. The eigenfrequencies are analysed in detail and the asymptotic expansion of eigenvalues are presented. It is shown that there is a set of generalized eigenfunctions for the closed‐loop system, which forms a Riesz basis with parentheses for the energy state space. This concludes the spectrum‐determined growth condition and the exponential stability of the closed‐loop system. Copyright © 2007 John Wiley & Sons, Ltd.
The bioavailability of raspberry anthocyanins and ellagitannins in rats
Authors: Borges Gina , Roowi Suri , Rouanet Jean‐Max , Duthie Garry G. , Lean Michael E. J. , Crozier Alan 
Published: May 2007

AbstractThe fate of anthocyanins and ellagitannins in rats was monitored following ingestion of raspberry juice. After 1 h low nM concentrations of unmetabolised anthocyanins were present in plasma but these declined by 2 h and after 4 h they were no longer detectable. For the first 2 h there was an almost full recovery of anthocyanins as they passed from the stomach through the duodenum/jejunum and into the ileum. After 3 h less than 50% were recovered, and the levels declined rapidly thereafter. Excretion of raspberry anthocyanins in urine over a 24 h period was equivalent to 1.2% of the amount ingested. Trace quantities of anthocyanins were detected in the caecum, colon and faeces and they were absent in extracts of liver, kidneys and brain. Urine also contained a number of phenolic acids but most were present in quantities well in excess of the 918 nmol of anthocyanins present in the ingested juice. These findings indicate that raspberry anthocyanins per se are poorly absorbed, probably prior to reaching the ileum, and that substantial amounts pass from the small to the large intestine where they are degraded by colonic bacteria. Ellagitannins disappeared in the stomach without accumulation of ellagic acid.
The bioavailability and absorption of anthocyanins: Towards a better understanding
Authors: McGhie Tony K. , Walton Michaela C. 
Published: May 2007

AbstractEvidence that anthocyanin compounds have beneficial effects for health are increasingly being reported in the scientific literature and these compounds are now widely recognised as potential therapeutic compounds. Berry fruit are rich sources of anthocyanins and berry fruit products or derived beverages can provide 10s to 100s of milligrams of anthocyanins in a single serve. Anthocyanins exhibit complex chemical behaviours in vitro and this will result in complex behaviour in vivo. This review attempts to summarize some aspects of anthocyanin biochemistry and discusses these in the context of what is currently known about bioavailability and absorption. Compared with other flavonoid groups, such as flavonols, relatively little is known about details and mechanisms of anthocyanin absorption and transport and much remains to be discovered.
Broadband flexible meander line antenna with vertical lines
Authors: Jung Jinwoo , Lee Hyeonjin , Lim Yeongseog 
Published: May 2007

AbstractA novel broadband meander‐line antenna with vertical lines is presented. The proposed antenna has a broadband impedance bandwidth of ∼785 MHz, which covers DCS, PCS, UMTS, WiBro, and WLAN bands. For frequencies across the operating bands, the proposed antenna displays omni‐directional radiation patterns. The proposed antenna has compact dimensions of 12 × 23.1 mm2. The antenna is flexible due to the F‐PCB material used. For these reasons, a cylindrical and folded structure is presented, as transformed from planar. Experimental results using the constructed prototype are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1984–1987, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22564