bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cathodoluminescence of ZnSiOx nanocomposite films prepared on Si substrates
Authors: Kim Young‐Hwan , Cho Woon‐Jo , Kim Seong‐Il 
Published: December 2008

AbstractOptoelectronic materials compatible with silicon substrates are important from the viewpoint of practical applications for silicon photonics. ZnO nanocrystals were fabricated directly on Si substrates by tuning both of the composition and postannealing conditions of ZnSiOx composite films deposited by sputtering Si and ZnO targets simultaneously. The high‐resolution TEM analysis showed that ZnSiOx nanocomposite film containing ZnO nanocrystals could be obtained by postannealing the ZnSiOx film with Zn/Si ratio = ∼1.6 at 700 °C. In this film, ZnO nanocrystals with a size of ∼5 nm, which could be identified as ZnO from electron diffraction pattern, were densely distributed in the amorphous matrix. This film exhibited a stronger and broader cathodoluminescence emission ranging from 350 nm to 550 nm compared to that of ZnO film fabricated with the same deposition conditions. These results lead to a practical application of ZnO nanocrystals to optoelectronic devices using Si substrates. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lithographic quantum dot for sensitive infrared photon detection
Authors: An Zhenghua , Ueda Takeji , Komiyama Susumu , Hirakawa Kazuhiko , Shen Xuechu 
Published: December 2008

AbstractSemiconductor quantum dots (QDs) with discrete energy levels provide a promising solution for infrared photon detection. A lithographically defined QD with split conduction subbands has been utilized as a photo‐active floating gate in a phototransistor structure. Electrons inside the QD are excited by incident infrared photons via intersubband transition and thereby tunnel out of the QD, lowering its electrostatic potential. As a consequence, photo‐signal arises as an electrical current increment in the phototransistor channel. It has been found that this though simple scheme exhibits a high sensitivity which is sufficient for detecting individual infrared photons (λ ∼ 14 μm).With continuous detection operation, more electrons are driven out of the QD. Eventually, the system approaches saturation due to over‐bended energy band profiles, therefore degrading the photo‐sensitivity. To alleviate this photo‐saturation effect, the QD electrostatic potential is controlled through a tuneable electrostatic potential barrier. Under illumination, the interplay between photo‐excitation and the potential barrier justifies the QD charge states, electrostatic potential and hence the channel current. It is found that, when the QD potential is externally lifted‐up, the device photo‐response can be enhanced clearly. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ramsey numbers of sparse hypergraphs
Authors: Conlon David , Fox Jacob , Sudakov Benny 
Published: December 2008

AbstractWe give a short proof that any k‐uniform hypergraph H on n vertices with bounded degree Δ has Ramsey number at most c(Δ,k)n, for an appropriate constant c(Δ,k). This result was recently proved by several authors, but those proofs are all based on applications of the hypergraph regularity method. Here we give a much simpler, self‐contained proof which uses new techniques developed recently by the authors together with an argument of Kostochka and Rödl. Moreover, our method demonstrates that, for k ≥ 4,

where the tower is of height k and the constant c depends on k. It significantly improves on the Ackermann‐type upper bound that arises from the regularity proofs, and we present a construction which shows that, at least in certain cases, this bound is not far from best possible. Our methods also allows us to prove quite sharp results on the Ramsey number of hypergraphs with at most m edges. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Soil respiration curves as soil fertility indicators in perennial central Amazonian plantations treated with charcoal, and mineral or organic fertilisers
Authors: Steiner Christoph , de Arruda Murilo Rodrigues , Teixeira Wenceslau G. , Zech Wolfgang 
Published: December 2008

AbstractWe assessed substrate‐induced respiration and soil chemical properties in order to study the influence of charcoal, nitrogen and phosphorus fertilisation on two different perennial crops in a confounded factorial design on a highly weathered Amazonian upland soil. Each plantation tested three different factors in three different levels making up 27 (33) treatment combinations. Whereas the banana plantation received mineral fertilisation in addition to charcoal applications (3rdfactor), the guarana (Paullinia cupana) plantation was fertilised organically using chicken manure and bone meal as the corresponding factors. Charcoal increased pH, total nitrogen, availability of sodium, zinc, manganese, copper and soil humidity, and decreased aluminium availability and acidity in the mineral‐fertilised plantation only. This caused a significant increase in basal respiration and microbial efficiency in terms of carbon dioxide release per microbial carbon in the soil. The microbial biomass, efficiency and population growth after substrate addition was significantly increased with increasing levels of organic fertiliser amendments. We conclude that charcoal is a valuable component especially in inorganic‐fertilised agricultural systems. Copyright © 2008 John Wiley & Sons, Ltd
Diagnosis, occurrence and seed transmission studies of viruses infecting four Centrosema species in Nigeria
Authors: Odedara OO , Hughes J d'A , Ayo‐John EI 
Published: December 2008

AbstractIn a survey to detect viruses affecting Centrosema species in two agroecological zones in Nigeria (the derived and northern guinea savanna zones: DSZ and NGSZ), enzyme‐linked immunosorbent assay of leaf samples of four species (C. brasilianum, C. pascuorum, C. pubescens and C. macrocarpum) revealed infections of two Potyviruses – Bean common mosaic virus and Cowpea aphid‐borne mosaic virus – and three Comoviruses – Cowpea mosaic virus, Cowpea severe mosaic virus and Bean pod mottle virus. Other viruses detected included: a Carmovirus, Cowpea mottle virus; a Cucumovirus, Cucumber mosaic virus (CMV); a Sobemovirus, Southern bean mosaic virus; and a Tobamovirus known as Tobacco mosaic virus (TMV). While no viruses were detected in leaf samples of C. brasilianum and C. pubescens collected from NGSZ, leaf samples of the same species collected from DSZ were highly infected, with the former being infected with seven viruses and the latter with all nine viruses tested for. Seed transmission studies of these viruses in Centrosema species showed CMV to be the most frequently detected, followed by TMV, and four different viruses were found in seeds of C. brasilianum in DSZ. The paper discusses the implications of these results for cropping of Centrosema legumes. Copyright © 2008 John Wiley & Sons, Ltd
First‐trimester maternal serum pregnancy‐associated plasma protein‐A and pre‐eclampsia
Authors: Poon L. C. Y. , Maiz N. , Valencia C. , Plasencia W. , Nicolaides K. H. 
Published: December 2008

AbstractObjectivesTo examine the relationship between low maternal serum pregnancy‐associated plasma protein‐A (PAPP‐A) and uterine artery pulsatility index (UtA‐PI) at 11 + 0 to 13 + 6 weeks with subsequent development of pre‐eclampsia (PE).MethodsUtA‐PI and serum PAPP‐A were measured in women attending for routine care at 11 + 0 to 13 + 6 weeks of gestation. In the population, 156 (1.9%) women developed PE, including 32 (0.4%) in whom delivery was before 34 weeks (early PE) and 124 (1.5%) with delivery at 34 weeks or more (late PE); 7895 (98.1%) women had no PE. Regression analysis was used to examine which of the factors amongst maternal characteristics, log PAPP‐A multiples of the median (MoM) and log UtA‐PI MoM contributed to the prediction of PE.ResultsThe median PAPP‐A MoM was 1.002 (interquartile range (IQR), 0.685–1.411) in the unaffected group, 0.555 (IQR, 0.463–0.922) in early PE and 0.911 (IQR, 0.580–1.247) in late PE. Serum PAPP‐A was below the 5th centile in 21.9% of early PE and 6.5% of late PE cases. The PAPP‐A‐related patient‐specific risk for PE was strongly influenced by maternal characteristics. There was a significant association between log UtA‐PI MoM and log PAPP‐A MoM (P = 0.001), and the detection rate of screening for PE by maternal variables and UtA‐PI was not improved by inclusion of PAPP‐A. Regression analysis was used to establish tables that allow modification of the maternal history and PAPP‐A‐related patient‐specific risk for PE by the measurement of UtA‐PI.ConclusionsLow PAPP‐A is a marker for subsequent development of PE. The PAPP‐A‐related patient‐specific risk for PE can be modified by the measurement of UtA‐PI. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Regulatory capitalism and the reassertion of the public interest
Authors: Levi-Faur David 
Published: December 2008

Abstract
Neoliberalism has not led to the retreat of the state but instead to the restructuring of the state. This has led to new forms of governance where regulation represents the expanding part of government, and where the various modes of governance compete and sometimes are synthesized into global forms of regulation. It will be discussed where such forms have emerged, and where they are yet to emerge. In this new order, best described as regulatory capitalism, the regulatory state meets the regulatory society and actors’ demand for and supply of regulation is ever expanding. Rule- making, monitoring and enforcement are becoming increasingly important for democratic policy making. It is being asserted that varieties of regulatory capitalism are produced by the interaction of varying degrees of civil- and state-regulation and variations in the composition of the networks that serve as the backbone that transform autonomous jurisdictions to interdependent ones. Accordingly the paper distinguishes between Corporatists, Pluralist, Command & Control and Laissez-Faire forms of regulatory capitalism.
The paradox of television privatization: When more is less
Authors: Feigenbaum Harvey B 
Published: December 2008

Abstract
The argument of this article is that privatization of the audiovisual sector has had unintended consequences. The proliferation of private television channels has fragmented advertising markets and created incentives for the increasing importation of cheap American programming. This phenomenon is evident despite the fact that the demand for such programming is eclipsed by audience preferences to see their own cultures on the small screen. Thus the paradox of television privatization is that, in cultural terms, it has led to less, rather than more, consumer choice. While the debates about Americanization have mostly dwelled on the loss of cultural diversity, the consequences for the domination of American popular culture have not only been the erosion of national identities, but also the transformation of local politics as people's political perceptions become increasingly affected by American political reference points and categories.
A theorem on approximation of irrational numbers by simple continued fractions
Authors: Tong Jingcheng 
Published: December 2008

Let ξ be an irrational number with simple continued fraction expansion ξ= [a0;a1,a2,…], Pn/qn be its nth convergent, . The following two theorems were proved by Müller [9] and rediscovered by Bagemihl and McLaughlin [1]:Theorem 1.For n>1,
A note on central idempotents in group rings II
Authors: Coelho Sônia P. , Milies C. Polcino 
Published: December 2008

Let G be a group and K a field. We shall denote by U(KG) the group of units of the group ring of G over K. Also, if X is a group, T(X) will denote the torsion subset of X, i.e., the set of all elements of finite order in X.Group theoretical properties of U(KG) have been studied intensively in recent years and it has been found that some conditions about U(KG) imply that T = T(G) must be a subgroup of G and that every idempotent of KT must be central in KG.
Invariant subspace theorems for amenable groups
Authors: Lau A. T. , Paterson A. L. T. , Wong J. C. S. 
Published: December 2008

In [5], Ky Fan proved the following remarkable amenability “invariant subspace” theorem:Let G be an amenable group of continuous, invertible linear operators acting on a locally convex space E. Let H be a closed subspace of finite codimension n in E and X⊂E be such that:(i) H and X are G-invariant;(ii) (e + H) ∩X is compact convex for all e ∈ E;(iii) X contains an n-dimensional subspace V of E. Then there exists an n-dimensional subspace of E contained in X and invariant under G.
Vanishing l1-sums of the Poisson kernel, and sums with positive coefficients
Authors: Bonsall F. F. , Walsh D. 
Published: December 2008

For z in D and ζ in ∂D, we denote by pz(ζ) the Poisson kernel (1 − │z│2)│1 − z̄ζ−2 for the open unit disc D. We ask for what countable sets {an:n∈ℕ} of points of D there exist complex numbers λn withby which we mean that the series converges to zero in the norm of L1(∂D).
Measure valued solutions of asymptotically homogeneous semilinear hyperbolic systems in one space variable
Authors: Demengel F. , Rauch J. 
Published: December 2008

We study systems which in characteristic coordinates have the formwhere A is a k × k diagonal matrix with distinct real eigenvalues. The nonlinearity F is assumed to be asymptotically homogeneous in the sense, that it is a sum of two terms, one positively homogeneous of degree one in u and a second which is sublinear in u and vanishes when u = 0. In this case, F(t, x, u(t)) is meaningful provided that u(t) is a Radon measure, and, for Radon measure initial data there is a unique solution (Theorem 2.1).The main result asserts that if μn is a sequence of initial data such that, in characteristic coordinates, the positive and negative parts of each component, , converge weakly to μ±, then the solutions coverge weakly and the limit has an interesting description given by a nonlinear superposition principle.Simple weak converge of the initial data does not imply weak convergence of the solutions.
The exponent of certain finite p-groups
Authors: York I. O. 
Published: December 2008

In this paper, for R a commutative ring, with identity, of characteristic p, we look at the group G(R) of formal power series with coefficients in R, of the formand the group operation being substitution. The results obtained give the exponent of the quotient groups Gn(R) of this group, n∈ℕ.
Representable divisibility semigroups
Authors: Bosbach Bruno 
Published: December 2008

By a divisibility semigroup we mean an algebra (S,., ∧) satisfying (Al) (S,.) is a semigroup; (A2) (S, ∧) is a semilattice; (A3).A divisibility semigroup is called representable if it admits a subdirect decomposition into totally ordered factors.In this paper various types of representable divisibility semigroups are investigated and characterized, admitting a representation in general or even a special decomposition, like subdirect sums of archimedean factors, for instance.
Totally geodesic surfaces in hyperbolic 3-manifolds
Authors: Reid Alan W. 
Published: December 2008

In this paper we investigate totally geodesic surfaces in hyperbolic 3-manifolds. In particular we show that if M is a compact arithmetic hyperbolic 3-manifold containing an immersion of a totally geodesic surface then it contains infinitely many commensurability classes of such surfaces. In addition we show for these M that the Chern-Simons invariant is rational.We also show, that unlike the figure-eight knot complement in S3, many knot complements in S3 do not contain an immersion of a closed totally geodesic surface.
Subnormal subgroups of En(R) have no free, non-abelian quotients, when n≧3
Authors: Mason A. W. 
Published: December 2008

It is known that for certain rings R (for example R = ℤ, the ring of rational integers) the group GL2(R) contains subnormal subgroups which have free, non-abelian quotients. When such a subgroup has finite index it follows that every countable group is embeddable in a quotient of GL2(R). (In this case GL2(R) is said to be SQ-universal.) In this note we prove that the existence of subnormal subgroups of GL2(R) with this property is a phenomenon peculiar to “n = 2”.For a large class of rings (which includes all commutative rings) it is shown that, for all , no subnormal subgroup of En(R) has a free, non-abelian quotient, when n≧3. (En(R) is the subgroup of GLn(R) generated by the elementary matrices.) In addition it is proved that, if is an SRt-ring, for some t ≧ 2, then no subnormal subgroup of GLn(R) has a free, non-abelian quotient, when n ≧ max (t, 3). From the above these results are best possible since ℤ is an SR3 ring.
Similarité entre l'algèbre de Volterra et un quotient d'algèbre uniforme
Authors: Koua Konin 
Published: December 2008

Two commutative Banach algebras A and B are said to be similar if there exists a Banach algebra D such that [xD]− = D for some x in D, and two one-to-one continuous homomorphisms φ:D→A and ψ:D→B such that φ(D) is a dense ideal of A and ψ(D) a dense ideal of B.We prove in this paper that the Volterra algebra is similar to A0/e-z A0 where A0 is the commutative uniform, separable Banach algebra of all continuous functions on the closed right-hand half plane , analytic on H and vanishing at infinity. We deduce from this result that multiplication by an element of A0/e-z A0 is a compact mapping.
Oscillations in a nonautonomous delay logistic difference equation
Authors: Philos Ch. G. 
Published: December 2008

Consider the nonautonomous delay logistic difference equationwhere (pn)n≧0is a sequence of nonnegative numbers, (ln)n≧0is a sequence of positive integers with limn→∞(n−ln) = ∞ andKis a positive constant. Only solutions which are positive forn≧0 are considered. We established a sharp condition under which all solutions of (E0) are oscillatory about the equilibrium pointK. Also we obtained sufficient conditions for the existence of a solution of (E0) which is nonoscillatory aboutK.
Asymptotic expansion of a series of Ramanujan
Authors: Berndt Bruce C. , Evans Ronald J. 
Published: December 2008

An asymptotic expansion is given for the seriesas x→∞ in the sector |Argx|≦π/2–δ. Here δ, Re(a), and Re(s) are positive and r is a positive integer. In the case a = r = s = 1, this yields the nontrivial resultstated by Ramanujan in his notebooks [6].
On semigroup presentations
Authors: Robertson Edmund F. , Ünlü Yusuf 
Published: December 2008

Semigroup presentations have been studied over a long period, usually as a means of providing examples of semigroups. In 1967 B. H. Neumann introduced an enumeration method for finitely presented semigroups analogous to the Todd–Coxeter coset enumeration process for groups. A proof of Neumann's enumeration method was given by Jura in 1978.In Section 3 of this paper we describe a machine implementation of a semigroup enumeration algorithm based on that of Neumann. In Section 2 we examine certain semigroup presentations, motivated by the fact that the corresponding group presentation has yielded interesting groups. The theorems, although proved algebraically, were suggested by the semigroup enumeration program.
On minimal thinness, reduced functions and Green potentials
Authors: Essén Matts 
Published: December 2008

Let Ω be an open connected subset of the unit disc U, let E = U\Ω and let {Ωk} be a Whitney decomposition of U. If z(Q) is the centre of the “square” Q, if T is the unit circle and t = dist.(Q, T), we considerwhere Ek = E ∩ Qk and c(Ek) is the capacity of Ek. We prove that the set E is minimally thin at τ ∈ T in U if and only if W(τ)< ∞. We study functions of type W and discuss the relation between certain results of Naim on minimal thinness [15], a minimum principle of Beurling [3], related results due to Dahlberg [7] and Sjögren [16] and recent work of Hayman-Lyons [15] (cf. also Bonsall [4]) and Volberg [19]. For simplicity, we discuss our problems in the unit disc U in the plane. However, the same techniques work for analogous problems in higher dimensions and in more complicated regions.
Oscillation results on y″ + Ay = 0 in the complex domain with transcendental entire coefficients which have extremal deficiencies
Authors: Chiang Y. M. 
Published: December 2008

Let A(z) be a transcendental entire function and f1, f2 be linearly independent solutions ofWe prove that if A(z) has Nevanlinna deficiency δ(0, A) = 1, then the exponent of convergence of E: = flf2 is infinite. The theorems that we prove here are similar to those in Bank, Laine and Langley [3].
Asymptotic tracts of harmonic functions II
Authors: Barth K. F. , Brannan D. A. 
Published: December 2008

An asymptotic tract of a real function u harmonic and non-constant in ℂ is a component of the set {z:u(z)≠c}, for some real number c; a quasi-tractT(≠ℂ) is an unbounded simply-connected domain in ℂ such that there exists a function u that is positive, unbounded and harmonic in T such that, for each point ζ∈∂T∩ℂ,and a ℱ-tract is an unbounded simply-connected domain T in ℂ whose every prime end that contains ∞ in its impression is of the first kind.The authors study the growth of a harmonic function in one of its asymptotic tracts, and the question of whether a quasi-tract is an asymptotic tract. The branching of either type of tract is also taken into consideration.
Projective resolutions for graph products
Authors: Cohen Daniel E. 
Published: December 2008

Let Γ be a finite graph together with a group Gv at each vertex v. The graph productG(Γ) is obtained from the free product of all Gv by factoring out by the normal subgroup generated by for all adjacent v, w.In this note we construct a projective resolution for G(Γ) given projective resolutions for each Gv, and obtain some applications.
Hyperbolic travelling fronts
Authors: Hadeler K. P. 
Published: December 2008

Since the work of R. A. Fisher [2] and Kolmogorov, Petrovskij and Piskunov [7] (see [6] for further references) the problem of travelling fronts in reaction–diffusion equations has been extensively studied. For the equationwith F(0) = F(1) = 0 a travelling front is a solutionwhere the function of one variable φ is decreasing and satisfies φ(−∞) = 1, φ(+∞) = 0. The function φ describes the shape of the front and the constant c is the speed of propagation. There are two main types of the problem. In the all-positive case, where the function F satisfiesthere is a half-line [c0, ∞), c0>0, of speeds. For each c∈[c0, ∞) there is, up to translation, a unique travelling front. Fronts for different c can be distinguished by the rate of decay towards +∞. In the threshold case, where F has the property, for some λ∈(0, 1),there is a unique speed c0 with a travelling front, which is unique up to translation. In this case the sign of c0 is determined by the sign of the integral
An algorithm for solving generalized algebraic Lyapunov equations in Hilbert space, applications to boundary value problems
Authors: Jódar Lucas 
Published: December 2008

Let L(H) be the algebra of all bounded linear operators on a separable complex Hubert space H. In a recent paper [7], explicit expressions for solutions of a boundary value problem in the Hubert space H, of the typeare given in terms of solutions of an algebraic operator equation
Multiparameter spectral theory and Taylor's joint spectrum in Hilbert space
Authors: Rynne B. P. 
Published: December 2008

Let n≧1 be an integer and suppose that for each i= 1,…,n, we have a Hilbert space Hi and a set of bounded linear operators Ti, Vij:Hi→Hi, j=1,…,n. We define the system of operatorswhere λ=(λ1,…,λn)∈ℂn. Coupled systems of the form (1.1) are called multiparameter systems and the spectral theory of such systems has been studied in many recent papers. Most of the literature on multiparameter theory deals with the case where the operators Ti and Vij are self-adjoint (see [14]). The non self-adjoint case, which has received relatively little attention, is discussed in [12] and [13].