bluuebunny/crossref_metadata_2025 huggingface dataset:
Approximation of Functions on [−1,1] and Their Derivatives by Polynomial Projection Operators
Authors: Balázs K. , Kilgore T.
Published: May 2007

Pointwise estimates are obtained for the simultaneous approximation of a function f ϵCq[‐1,1] and its derivatives f(1), …, f(q) by means of an arbitrary sequence of bounded linear projection operators Ln which map C[‐1,1] into the polynomials of degree at most n, augmented by the interpolation of f at some points near ± 1.
Approximation by Spherical Functions
Authors: König Hermann
Published: May 2007

Results on the degree of approximation of continuous or Lipschitz‐continuous functions f:Sn−1 → ℝ on the sphere in ℝn by spherical functions of degree k are given in terms of k and n, strengthening results of Newman and Shapiro. An example of (restriction of) a norm shows the result to be the best possible in k and n. Further, results for smoother functions are discussed.
Weak Uniform Rotundity of Orlicz Sequence Spaces
Authors: Doman Malgorzata
Published: May 2007

Necessary and sufficient conditions are given for weak uniform rotundity of Orlicz sequence spaces equipped with the Luxemburg norm.
Two Projection Theorems and Symbol Calculus for Operators with Massive Local Spectra
Authors: Finck T. , Roch S. , Silbermann B.
Published: May 2007

In this paper we construct a symbol calculus for Banach algebras generated by two idempotents and a coefficient algebra. This, combined with local principles for „embedding algebras”︁, leads to a symbol calculus for singular integral operators on spaces with Muckenhoupt weight and for singular integral operators with measurable coefficients.
Orthogonal Systems of Eigenvectors and Associated Vectors for Symmetric Holomorphic Operator Functions
Authors: Möller Manfred
Published: May 2007

In Banach spaces the principal parts of the inverse of a holomorphic Fredholm valued operator function can be written as sums of tensor products of biorthogonal canoncial systems of eigenvectors and associated vectors of the operator function and its adjoint. If we impose a symmetry condition on the operator function, then for real eigenvalues the eigenvectors and associated vectors of the operator function and its adjoint coincide at this point. We shall show that we can always choose a suitable canonical system of eigenvectors and associated vectors which is orthogonal, i.e., biorthogonal to itself. An application to elliptic differential operators is given.
Mean Convergence of Derivatives of Extended Lagrange Interpolation with Additional Nodes
Authors: Criscuolo Giuliana , Mastroianni Guiseppe , Nevai Paul
Published: May 2007

Weighted Lp convergence of derivatives of extended Lagrange interpolation at the union of zeros of generalized Jacobi polynomials and some additional points is investigated.
A Linearized Oscillation Result for Neutral Delay Differential Equations
Authors: Yu Jianshe , Wang Zhicheng
Published: May 2007

We consider the first order nonlinear neutral delay differential equationequation imageand establish a linearized oscillation result of Eq. (1) whenP(t)≥ 1, which answers partially an open problem proposed by GYÖRI and LADAS.
A Generalization of the Arnold‐Wendland Lemma to a Modified Collocation Method for Boundary Integral Equations in ℝ3
Authors: Hsiao George C. , Prössdorf Siegfried
Published: May 2007

We prove quasioptimal and optimal order estimates in various Sobolev norms for the approximation of linear strongly elliptic periodic pseudodifferential equations in two independent variables by a modified method of nodal collocation by odd degree polynomial splines. In the one‐dimensional case, our method coincides with the method of nodal collocation when odd degree polynomial splines are employed for the trial functions. The convergence analysis is based on an equivalence which we establish between our method and a nonstandard Galerkin method for an operator closely related to the given operator. This equivalence is realized through a crucial intermediate result (which we now term the Arnold‐Wendland lemma) to connect the solution of central finite difference equations and that of certain nonstandard Galerkin equations. The results of this paper are genuine two‐dimensional generalizations of the results obtained by ARNOLD and WENDLAND in [2] for the one‐dimensional equations.
On the MacNeille Completion of the Category of Partially Ordered Topological Spaces
Authors: Schauerte A.
Published: May 2007

Preordered topological spaces for which the order has a closed graph form a topological category. Within this category we identify the MacNeille completions (coinciding with the universal initial completions) of five monotopological subcategories, namely those of the T0(T1, T2) preordered spaces and the (completely regular) partially ordered spaces. We also show that a functor due to L. NACHBIN from the quasi‐uniform spaces to the preordered spaces preserves initial sources.
On the Titchmarsh‐Weyl Coefficients for Singular S‐Hermitian Systems I
Authors: Hinton D. B. , Schneider A.
Published: May 2007

Singular S‐Hermitian systems are studied with the goal of defining a Titchmarsh‐Weyl M(λ)‐coefficient directly in terms of separated, selfadjoint boundary conditions. A general deficiency index is allowed. The resolvent operator is constructed and a self‐adjoint operator A is constructed in the Hilbert space which gives an equivalent description of the singular S‐Hermitian boundary value problem.
Inserting L‐fuzzy Real‐valued Functions
Authors: Kotzé Wesley , Kubiak Tomasz
Published: May 2007

A new proof of the Katêtov‐Tong Insertion Theorem for L‐fuzzy topological spaces is given. All the proofs are performed in such a way that the presented results hold true in the more general case in which L‐fuzzy topologies are replaced by σ‐additive rings of L‐fuzzy subsets.
Necessary and Sufficient Conditions for a Fourth Order Functional Differential Equation to be Oscillatory
Authors: Gopalsamy K. , Wen Lizhi , Chen Yong‐Shao , He Xue‐Zhong
Published: May 2007

Necessary and sufficient conditions for a fourth order functional differential equation of the form

(1) [r(t)y″(t)]″+f(t,y(h1(t)), y(h2(t)), …, y(hn(t)))=0

to be oscillatory are given when f is strongly superlinear or strongly sublinear.
The Inequality 8pg < μ for Hypersurface Two‐dimensional Isolated Double Points
Authors: Tomari Masataka
Published: May 2007

The Milnor number μ and the geometric genus pg of normal 2‐dimensional double points are studied by using Zariski's canonical resolution. By using formulas due to E. HORIKAWA and H. LAUFER, we represent μ − 8pg in terms of the number of blowing‐ups along ℙ1 and the number l of „even”︁ components in the resolution process. A key point of our arguments is the fact that if l is small then the resolution process is restricted very much. For rational double points and double points with pa = 1, each classes are characterized by numerical invariants appearing in this resolution process. For the case pa = 1, we can make our inequality sharper and can prove 12 · pg − 3 ≤ μ. This is an another proof of Xu‐Yau's inequality for the singularity with pa = 1 in our situation.
Conditional Local States and Decomposition of Locally Normal States
Authors: Liebscher Volkmar
Published: May 2007

For infinite boson systems in the framework of [5, 9] it is proven that all locally normal states possess conditional local states. This result is used to find a tail‐field‐measurable decomposition of these states and to characterize their position distributions in completion to [6] as ‐Point processes. As an example mixed coherent states are investigated.
Continuous Linear Extension of Ultradifferentiable Functions of Beurling Type
Authors: Franken Uwe
Published: May 2007

For a weight function ω and a closed set A ⊂ ℝN let ℰ(ω)(A) denote the space of all ω‐Whitney jets of Beurling type on A. It is shown that for each closed set A ⊂ ℝN there exists an ω‐extension operator EA: ℰ(ω)(A) → ℰ(ω)(ℝN) if and only if ω is a (DN)‐function (see MEISE and TAYLOR [18], 3.3). Moreover for a fixed compact set K ⊂ ℝN there exists an ω‐extension operator EK: ℰ(ω)(K) → ℰ(ω)(ℝN) if and only if the Fréchet space ℰ(ω)(K) satisfies the property (DN) (see Vogt [29], 1.1.).
An Uncertainty Principle for Commutative Hypergroups and Gelfand Pairs
Authors: Voit Michael
Published: May 2007

We extend sharp forms of the classical uncertainty principle to the context of commutative hypergroups. This hypergroup setting includes Gelfand pairs, Riemannian symmetric spaces, and locally compact abelain groups. For some Gelfand pairs our inequalities will be sharper than those in a recent paper by J. A. WOLF.
Oscillations and Convergence in a Diffusive Delay Logistic Equation
Authors: Gopalsamy K. , He Xue‐Zhong , Sun Da‐Qing
Published: May 2007

Sufficient conditions are obtained for all positive solutions of the diffusive delay‐logistic system magnified image to be oscillatory about the positive equilibrium K. A comparison result is established with which the global asymptotic stability of the positive equilibrium is investigated.
Equilibrium States and Hausdorff Measures for Interval Maps
Authors: Hofbauer Franz , Keller Gerhard
Published: May 2007

For a class of piecewise monotone interval maps T (including unimodal maps with negative Schwarzian derivative) and real valued functions f of bounded variation we compare equilibrium states μ of f with Hausdorff measures v and give an integral test for the dichotomy μ ≪ v or μ ⊥ v. For certain classes of rational maps such a result was proved in [15] and [3].
On the Stability of Multi‐dimensional Convexity under Interpolation
Authors: Salvatori Maura , Vignati Marco
Published: May 2007

The relations between the k‐uniform convexity of Banach spaces and both the real and the complex method of interpolation are studied. Estimates on the behaviour of the moduli of k‐rotundity are given.
Leray‐Schauder Degree Method in Functional Boundary Value Problems Depending on the Parameter
Authors: Stanêk Svatoslav
Published: May 2007

Using the Leray‐Schauder degree method sufficient conditions for the one‐parameter boundary value problem x″ = f(t, x, x′, λ), α(x) = A, x(0) − x(1) = B, x′(0) − x′(1) = C, are stated. The application is given for a class of functional boundary value problems for nonlinear third‐order functional differential equations depending on the parameter.
Weighted (LF)‐spaces of Continuous Functions
Authors: Bierstedt Klaus D. , Bonet José
Published: May 2007

magnified image.
An Omega Theorem for a Class of Arithmetic Functions
Authors: Kühleitner Manfred , Nowak Werner Georg
Published: May 2007

This paper deals with the average order of arithmetic functions a(n) with a generating function of the shape (1.1) where fk and gj possess certain characteristic properties of the zera‐function. Under fairly general conditions, a lower bound for the error term in the asymptotic formula for the corresponding Dirichlet summatory function is established. Finally, several specific applications to functions from elementary number theory and to arithmetic problems in number fields are discussed.
On Singular Integral Operators with Bounded Measurable Coefficients
Authors: Andrew Paul
Published: May 2007

Necessary and sufficient analytical conditions are determined for a singular integral operator of the form aP + bQ with bounded measurable coefficients to be a ϕ‐operator on Lp(Γ) for all 1 < p < ∞. where Γ is a closed Lyapunov curve.
Inosine monophosphate dehydrogenase (IMPDH) as a target in drug discovery
Authors: Shu Qingning , Nair Vasu
Published: May 2007

Inosine monophosphate dehydrogenase (IMPDH) is a key enzyme of de novo purine nucleotide biosynthesis and is viewed as an important target in the quest for discovery of drugs in the antiviral, antibacterial and anticancer therapeutic areas. This review focuses on the medicinal chemistry, drug discovery and chemical biology of IMPDH. Examples of IMP and cofactor site‐directed inhibitors, allosteric inhibitors and isoform‐selective inhibitors are presented. Comparison of IMPDHs from different organisms is also made to facilitate the design of species‐selective IMPDH inhibitors for drug discovery. Special emphasis in the review is placed on IMPDH from Mycobacterium tuberculosis. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 2, 219–232, 2008
Investigation of the Gel Effect in Reactive Extrusion Processes for Free Radical Polymerization
Authors: Zhang Guofang , Jia Yuxi , Sun Sheng , Wu Lili , Zhao Guoqun , An Lijia
Published: May 2007

The gel effect in the reactive extrusion process for free radical polymerization in a closely intermeshing co‐rotating twin screw extruder was investigated. First the reaction kinetic model was constructed mainly on the basis of entanglement theory. Next, numerical calculation expressions for the initiator and monomer concentrations, monomer conversion, average molecular weight and apparent viscosity were deduced. Finally, the evolution of the above variables were shown and discussed for the example of butyl methacrylate. The simulated results of the monomer conversion are in good agreement with experimental results.

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Industrial SBR Process: Computer Simulation Study for Online Estimation of Steady‐State Variables Using Neural Networks
Authors: Minari Roque J. , Stegmayer Georgina S. , Gugliotta Luis M. , Chiotti Omar A. , Vega Jorge R.
Published: May 2007

This work investigates the industrial production of styrene‐butadiene rubber in a continuous reactor train, and proposes a soft sensor for online monitoring of several processes and polymer quality variables in each reactor. The soft sensor includes two independent artificial neural networks (ANN). The first ANN estimates monomer conversion, solid content, polymer production, average particle diameter, and average copolymer composition; the second ANN estimates average molecular weights and average branching degrees. The required ANN inputs are: (i) the reagent feed rates into the first reactor and (ii) the reaction heat rate in each reactor. The proposed ANN‐based soft sensor proved robust to several measurement errors, and is suitable for online estimation and closed‐loop control strategies.

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Prediction of Chain Length Distribution of Polystyrene Made in Batch Reactors with Bifunctional Free‐Radical Initiators Using Dynamic Monte Carlo Simulation
Authors: Maafa Ibrahim M. , Soares João B. P. , Elkamel Ali
Published: May 2007

The objective of this paper is to present a dynamic Monte Carlo model that is able to simulate the polymerization of styrene with bifunctional free‐radical initiators in a batch reactor. The model can predict the dynamic evolution of the chain length distribution of polystyrene in the reactor. The model includes all relevant polymerization mechanistic steps, including chemical and thermal radical generation, and diffusion‐controlled termination. The model was applied to styrene polymerization and the Monte Carlo estimates for chain length averages were compared to those obtained with the method of moments. Excellent agreement was obtained between the two methods. Although styrene polymerization was used as a case study, the proposed methodology can be easily extended to any other polymer type made by free‐radical polymerization.

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The effects of ovariectomy and estrogen replacement on acetylcholine release from nerve fibres and passive stretch‐induced acetylcholine release in female rat bladder
Authors: Yoshida Junya , Aikawa Ken , Yoshimura Yasukuni , Shishido Keiichi , Yanagida Tomohiko , Yamaguchi Osamu
Published: May 2007

Aims

The present study investigated the effects of ovariectomy and estrogen replacement on the release of acetylcholine (Ach) from cholinergic neurons as well as on the tetrodotoxin (TTX)‐insensitive stretch‐induced Ach release in isolated rat detrusor. In addition, the above effects on rat micturition characteristics were also studied.

Methods

Thirty female rats randomly received a sham operation, ovariectomy, or ovariectomy plus estrogen replacement. Using metabolic cages, micturition parameters were recorded. Then, in vitro functional experiments that included the measurements of nerve‐mediated detrusor muscle contraction, Ach release from nerve fibres, and stretch‐induced TTX‐insensitive Ach release were performed. Ach release was measured using microdialysis and high‐performance liquid chromatography.

Results

Ovariectomized rats showed a significant decrease in voided volume and significant increase in 24‐hr frequency of voiding. Ovariectomy caused the significant increase in both TTX‐insensitive basal Ach release and TTX‐insensitive stretch‐induced Ach release. On the other hand, ovariectomy caused a significant decrease in Ach release from nerve fibres, resulting in the decrease in the contractile responses of detrusor muscle to electrical nerve stimulation. Estrogen replacement restored these alterations induced by ovariectomy.

Conclusions

Our findings showed that as a results of estrogen deficiency, Ach release from nerve fibres decreased, suggesting that this reduction of Ach released from cholinergic nerves may cause the decrease in detrusor contractility. Furthermore, this study also demonstrated that stretch‐induced TTX‐insensitive Ach release was increased by ovariectomy. This may be a contributing factor to the development of overactive bladder in elderly women. Neurourol. Urodynam. 26:1050–1055, 2007. © 2007 Wiley‐Liss, Inc.
Pudendal nerve stimulation evokes reflex bladder contractions in persons with chronic spinal cord injury
Authors: Yoo Paul B. , Klein Stephen M. , Grafstein Neil H. , Horvath Eric E. , Amundsen Cindy L. , Webster George D. , Grill Warren M.
Published: May 2007

Aims

Although electrical stimulation of the pudendal nerve has been shown to evoke reflex micturition‐like bladder contractions in both intact and spinalized cats, there is little evidence to suggest that an analogous excitatory reflex exists in humans, particularly those with spinal cord injury (SCI). We present two cases where electrical activation of pudendal nerve afferents was used to evoke excitatory bladder responses.

Subjects and Methods

A percutaneously placed catheter electrode was used to electrically stimulate the pudendal nerve trunk in two males with SCI. The response was quantified with recorded changes in detrusor pressure and EMG activity of the external anal sphincter.

Results

In both individuals, frequency specific (f = 20–50 Hz) activation of the pudendal nerve trunk evoked excitatory bladder contractions that also depended on the stimulus amplitude and bladder volume.

Conclusion

The results suggest that selective activation of the perineal branches of the pudendal nerve may further augment the excitatory reflex evoked by electrical stimulation. Neurourol. Urodynam. 26:1020–1023, 2007. © 2007 Wiley‐Liss, Inc.
Divided leadership
Authors: Davis I. Ridgway
Published: May 2007

Separate election of lieutenant governor seen as weakening office, distorting succession.
A posteriori error estimates of mixed methods for miscible displacement problems
Authors: Chen Yanping , Liu Wenbin
Published: May 2007

The miscible displacement of one incompressible fluid by another in a porous medium is governed by a system of two equations. One is an elliptic equation of the pressure and the other is a parabolic equation of the concentration of one of the fluids. Since the pressure appears in the concentration only through its velocity field, we choose a mixed finite element method to approximate the pressure equation and for the concentration we use the standard Galerkin method. We shall obtain an explicit a posteriori error estimator in L2(L2) for the semi‐discrete scheme applied to the non‐linear coupled system. Copyright © 2007 John Wiley & Sons, Ltd.
Laparoscopic versus open abdominal surgery in children with sickle cell disease is associated with a shorter hospital stay
Authors: Goers Trudie , Panepinto Julie , DeBaun Michael , Blinder Morey , Foglia Robert , Oldham Keith T. , Field Joshua J.
Published: May 2007

Background

Limited information exists comparing the post‐operative complication rate of laparoscopic or open abdominal surgeries in children with sickle cell disease (SCD). The primary objective of this study was to compare the outcomes in children with SCD who required laparoscopic or open abdominal surgery for a cholecystectomy or splenectomy.

Procedure

We conducted a retrospective analysis of laparoscopic and open abdominal surgeries performed in children with SCD (ages 0–20 years) at two medical centers from 1984 to 2004. The primary outcome measures were the rates of post‐operative pain and acute chest syndrome (ACS) episodes following laparoscopic or open abdominal surgery. The secondary outcome was length of hospital stay following surgery. We also examined the potential contribution of pre‐operative (transfusion) and intra‐operative factors (operating time, estimated blood loss, and end‐operative temperature) to post‐operative SCD‐related complications.

Results

A total of 140 cases were identified, 98 laparoscopic and 42 open. Episodes of post‐operative pain and ACS episodes were comparable between laparoscopic and open procedures (pain: 4% vs. 3%, P = 0.619; ACS: 5% vs. 5%, P = 0.933). Additionally, laparoscopic surgeries were associated with a significantly shorter hospital stay (2.9 vs. 5.4 days, 95% CI −3.7 to −1.4, P < 0.001). There was no difference in the number of hospital readmissions within 1 month of the surgery.

Conclusions

For children with SCD who need a cholecystectomy or splenectomy, laparoscopy is the preferred strategy because of a shorter hospital stay with a similar complication rate compared to open surgeries. Pediatr Blood Cancer 2008;50:603–606. © 2007 Wiley‐Liss, Inc.
Thermomechanical studies of aluminum nitride filled shape memory polymer composites
Authors: Razzaq Muhammad Yasar , Frormann Lars
Published: May 2007

High thermal conductivity polyurethane shape memory polymer (SMP) composites filled with aluminum nitride (AlN) were fabricated, and their thermal and thermomechanical properties were studied. The purpose of this microstructure is to improve the thermal properties of the SMPs at low filler content. Morphology of AlN filler in polyurethane SMP matrix and the resulting thermal conductivity was also investigated. Thermal studies have shown that AlN is an effective filler for reinforcement of the polyurethane SMP and that it does not deteriorate the stable physical crosslink structure of the polyurethane, which is necessary to store the elastic energy in the service process of the shape memory material. The thermal conductivities of these SMP composites in relation to filler concentration and temperature were investigated, and it was found that the thermal conductivity can increase up to 50 times in comparison with that of the pure SMP. Furthermore, differential scanning calorimetry tests have shown a significant decrease in the glass transition temperature of the switching segment. Dynamic mechanical studies have shown that the storage modulus of the composites increase with higher AlN content in both glassy and rubbery state. Damping peak decreases and also the curve of damping becomes broader with increasing filler content. Strain fixity rate which expresses the ability of the specimens to fix their strain has been improved slightly in the presence of AlN filler but the final recovery rate of the shape memory measurement has decreased evidently. POLYM. COMPOS., 28:287–293, 2007. © 2007 Society of Plastics Engineers
Kevlar and glass fiber treatment for thermoplastic composites by step polycondensation
Authors: Salehi‐Mobarakeh H. , Nakata S. , Ait‐Kadi A. , Brisson J.
Published: May 2007

Nylon‐6,6 was grafted at the surface of glass and plasma‐treated Kevlar fibers for use in nylon–Kevlar thermoplastic composites. Hydroxyl and, in the case of Kevlar, amine end‐groups occur at the fibre surface, either as defects or due to the plasma treatment. These were used as anchor points for nylon‐6,6 step polycondensation. Fibers were subjected to successive dipping in adipoyl chloride/CH2Cl2 and aqueous hexamethylenediamine solutions in order to attach and grow high molecular weight polymer on the fiber surface. Grafted nylon was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, differential scanning calorimetry and thermogravimetry. It was shown that no backbiting occurred during the first stage of the grafting process and that the polymer quantity increased linearly with number of passes, up to ∼50 passes for plasma‐treated Kevlar and 100 for glass fibers, after which polymer quantity remained constant, within experimental error, which was attributed to the onset of termination reactions. POLYM. COMPOS., 28:278–286, 2007. © 2007 Society of Plastics Engineers
Ground currents in single‐phase transformerless photovoltaic systems
Authors: Gubía Eugenio , Sanchis Pablo , Ursúa Alfredo , López Jesús , Marroyo Luis
Published: May 2007

The relative weight of the energy generated by means of renewable sources is constantly increasing. Among all these sources, the photovoltaic (PV) systems present the higher and more stable relative growth. However, the PV system is still too expensive and a significant effort is being done to increase the efficiency and reduce the cost. Concerning the PV inverters, this has lead to the elimination of the low frequency (LF) transformer that has been traditionally included. The LF transformer provides isolation from the grid but reduces the PV inverter efficiency and increases its size and cost. However, the elimination of the transformer might generate strong ground currents, which become now an important design parameter for the PV inverter. The ground currents are a function of the system stray elements. However, there is no simple model and procedure to study the common mode behavior of a PV system, which is required to analyze the ground currents. In this paper, a comprehensible model is proposed which provides a better understanding of the common mode issue in single‐phase transformerless PV systems. In addition, a procedure is developed to analyze the global performance, efficiency, grid current quality, and common mode behavior of a PV inverter as a function of its particular structure and modulation technique. Copyright © 2007 John Wiley & Sons, Ltd.
Novel poly(pyridine imide) with pendent naphthalene groups: Synthesis and thermal, optical, electrochemical, electrochromic, and protonation characterization
Authors: Liaw Der‐Jang , Wang Kun‐Li , Chang Feng‐Chyuan , Lee Kueir‐Rarn , Lai Juin‐Yih
Published: May 2007

A new diamine containing a pyridine heterocyclic group and a naphthalene substituent, 4‐(2‐naphthyl)‐2,6‐bis(4‐aminophenyl) pyridine (NBAPP), was synthesized with the Chichibabin reaction and used in the preparation of poly(pyridine imide) by direct polycondensation with 4,4′‐hexafluoroisopropylidenediphathalic anhydride in N‐methyl‐2‐pyrrolidinone (NMP). The poly(pyridine imide) derived from diamine NBAPP with naphthalene substituents was highly organosoluble: it was soluble in tetrahydrofuran, NMP, N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide, and γ‐butyrolactone at room temperature and in pyridine, dimethyl sulfoxide, and cyclohexanone upon heating at 70 °C. The poly(pyridine imide) was converted into lightly colored, optically transparent, flexible, and tough polyimide films via casting onto glass from a DMAc solution. This polymer exhibited good thermal stability (temperature of 10% weight loss = 527 °C) in air and high dielectric constants (as high as 4.20 at 1 kHz). The polyimide films had a tensile strength of 102 MPa and a tensile modulus of 1.8 GPa. As for the optical properties, the polymer exhibited UV–vis absorption bands in the region of 223–450 nm and possessed strong green‐yellow fluorescence (500 nm) after being protonated with acid. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2367–2374, 2007
The fluorescence transition of 2‐aminopurine in double‐ and single‐stranded DNA
Authors: Hardman Samantha J. O. , Thompson Katherine C.
Published: May 2007

2‐Aminopurine (2AP) is a widely used marker for nucleic acid structure because the fluorescence of 2AP in double‐stranded DNA is approximately half that of 2AP in single‐stranded DNA. The underlying photophysical mechanism responsible for the change in fluorescence with structure is not understood. We have performed CIS and TDB3LYP level calculations on double‐stranded trinucleotide models, (X2APX)·(YTY), where X and Y represent the natural nucleobases. The results reveal that base stacking combined with hydrogen bonding reduces the oscillator strength for the fluorescence transition, and hence the fluorescence quantum yield. It is also shown that the electronic transitions of double‐stranded trinucleotides are not simply those of the individual bases, but rather involve orbitals that are delocalized across several bases. Although the results obtained at the CIS level suffer from the neglect of electron correlation, the results obtained at the TDB3LYP level are not necessarily better because this method has problems describing long‐range interactions and tends to underestimate the energies of charge‐transfer states. Calculations on a full (rather than model) dinucleotide 5′‐G2AP‐3′ confirm that the inclusion of the sugar and phosphate groups is not necessary when studying the energetically low‐lying excited states of nucleic acids containing 2AP. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Lipid composition of membranes of Escherichia coli by liquid chromatography/tandem mass spectrometry using negative electrospray ionization
Authors: Oursel Delphine , Loutelier‐Bourhis Corinne , Orange Nicole , Chevalier Sylvie , Norris Victor , Lange Catherine M.
Published: May 2007

A liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method using reversed‐phase chromatography was developed for the analysis of phospholipids from bacterial extracts of a wild‐type strain of Escherichia coli. Product ion mass spectra from [MH]− precursor ions allowed an identification of individual phospholipid species that includes both fatty acid composition and fatty acyl location on the glycerol backbone using diagnostic product ions. Thus, complete assignment, including sn‐1/sn‐2 fatty acyl position, was achieved for this strain of E. coli. In addition, the phospholipids were quantified relative to one another using an internal standard method. Copyright © 2007 John Wiley & Sons, Ltd.
What we learn from the study of ubiquitous processes
Authors: Osterweil Leon J.
Published: May 2007

Software engineering has come to recognise the value of software processes as vehicles for addressing such goals as improved efficiency in software development, the achievement of improved product quality, and better coordination and communication of the members of software teams. Greater clarity, completeness, and precision in defining these processes seem to lead to greater effectiveness in pursuing these goals. The languages and notations used to support definition of such processes seem to be relatively successful in supporting these definitions, but more progress towards better languages and notations seems indicated. This article suggests that processes are also central to the effective pursuit of essential goals in a broad spectrum of other domains of human endeavour. We suggest that the study of how processes are used in those other domains to pursue goals that are essential in those domains can help us to reflect on our goals for the use of process in software development. Further, we suggest that observing the process language features that seem to facilitate the pursuit of goals in these other domains can similarly suggest features that would seem analogously important in languages used to support the definition of software processes. This article examines the use of processes in domains other than software development and uses observations about these processes to suggest desiderata for software development processes, and the languages used to define them. Copyright © 2007 John Wiley & Sons, Ltd.
Clinical Usefulness of Chest Radiography in Detection of Pulmonary Metastases After Curative Resection for Colorectal Cancer
Authors: Lee Won‐Suk , Yun Seong Hyeon , Chun Ho‐Kyung , Lee Woo Yong , Yun Haeran
Published: May 2007

Purpose

The purpose of this study was to evaluate the effectiveness of chest radiography (CXR) and abdominal computed tomography (CT) for detecting pulmonary metastases after curative surgery for colorectal cancer.

Methods

We performed a retrospective analysis of the records of all patients with pulmonary metastasis from colorectal cancer who underwent curative resection between 1994 and 2004 at our institution.

Results

Pulmonary metastases were detected in 193 patients by either CXR or abdominal CT. They were initially detected by CXR in 87 patients (45.1%) and by abdominal CT in 106 patients (54.9%). In the CXR group, the patterns of pulmonary recurrence were as follows: solitary (n = 38, 43.7%), multiple unilateral (n = 11, 12.6%), and multiple bilateral (n = 38, 43.7%). In the CT group, there were 22 patients (20.8%) with a solitary nodule, 17 patients (16.0%) with multiple unilateral nodules, and 67 (63.2%) with multiple bilateral nodules. The overall survivals of the CXR group and abdominal CT group were 34.6% and 31.7%, respectively (p = 0.312). There was no difference in the median disease‐free interval between the CXR group and the abdominal CT group (23.8 vs. 23.2 months, p = 0.428).

Conclusions

Although this study is limited by its small sample size, it can be speculated that abdominal CT with lower thorax images may replace CXR in surveillance programs.
Mitochondrial DNA-related Disorders
Authors: Mancuso Michelangelo , Filosto Massimiliano , Choub Anna , Tentorio Marta , Broglio Laura , Padovani Alessandro , Siciliano Gabriele
Published: May 2007

Mitochondrial diseases are a group of disorders due to a mitochondrial respiratory chain deficiency. They may depend on mitochondrial genome (mtDNA-related disorders) as well as on a nuclear genome defect (nDNA-related disorders). mtDNA-related disorders encompass an increasing number of clinical pictures associated with more than 250 different provisional or confirmed pathogenic changes in mtDNA. Although some clinical syndromes are nosologically defined, most of the cases present with polymorphous phenotypes ranging from pure myopathy to multi-system involvement. Complexity of mitochondrial genetics is in part responsible for the extreme clinical intra- and inter-familial heterogeneity of this group of diseases. In this review, we briefly report an updated classification and overview the main clinical pictures of this class of diseases.
Prolapse severity, symptoms and impact on quality of life among women planning sacrocolpopexy
Authors: FitzGerald M.P. , Janz N.K. , Wren P.A. , Wei J.T. , Weber A.M. , Ghetti C. , Cundiff G.W. ,   for the Pelvic Floor Disorders Network
Published: May 2007

Objectives: To explore the relationship between severity of pelvic organ prolapse (POP), symptoms of pelvic dysfunction and quality of life using validated measures. Method: Baseline data from 314 participants in the Colpopexy And Urinary Reduction Efforts (CARE) trial were analyzed. Pelvic symptoms and impact were assessed using the Pelvic Floor Distress Inventory (PFDI) and the Pelvic Floor Impact Questionnaire (PFIQ). PFDI and PFIQ scores were compared by prolapse stage and history of incontinence or POP surgery. Regression analyses were performed to identify other predictors of symptoms and impact. Results: Women were predominantly (90%) Caucasian and had mean age of 61 years. Women with stage II POP, especially those with prior surgery, reported more symptoms and impact than women with more advanced POP. There were no other significant predictors of symptoms or life impact. Conclusions: Women planning sacrocolpopexy with stage II prolapse and prior pelvic surgery reported more symptoms and quality of life impact than those with more advanced prolapse.
On the Origins of ISI: The Latin American Cement Industry, 1900–30
Authors: TAFUNELL XAVIER
Published: May 2007

This article explores the achievements of industrialisation in Latin America in the period before 1930, the date traditionally considered to be the start of the ISI process. It analyses the development of a basic industrial sector, the cement industry, which was driven by a natural substitution of imports. It quantifies the expansion of demand in each of the countries in the region, and then moves on to consider the growth of the industry in Latin America in the period between 1900 and 1930. Although cement consumption grew briskly, particularly in the most underdeveloped economies, disparities in levels of consumption and production among countries in the region continued to be very great in 1930, while the gap between Latin America and the most industrialised economies grew slightly.
Political Space, Pro-Poor Growth and Poverty Reduction Strategy in Honduras: A Story of Missed Opportunities
Authors: CUESTA JOSE
Published: May 2007

This article assesses the political and socio-economic consequences of the Poverty Reduction Strategy (PRS) in Honduras. The analysis deploys several techniques, including poverty narratives, stakeholder analysis and taxonomy analysis, and is also based on quantitative and qualitative data, including socio-economic indicators, PRS spending execution and interviews with stakeholders. It argues that in Honduras the PRS constituted a missed opportunity to expand the political space in which poverty reduction plans are formulated and to deliver pro-poor growth. The inclusion of multiple actors with different interests, capacities and influence led to an emphasis on constructing consensus, but this was too imprecise to enable a clear set of priorities to be articulated, let alone a pro-poor growth agenda. The article concludes that by unilaterally shifting the growth pillar of the PRS towards infrastructure investments and trade integration, Honduras may have sacrificed an opportunity to support a truly participatory democratic process leading to effective pro-poor policies.
Organizational Identity as a Constraint on Strategic Action: A Comparative Analysis of Gay and Lesbian Interest Groups
Authors: Engel Stephen M.
Published: May 2007

Interest groups can seek legislative action through state and national legislatures, partnerships with presidents, governors, or mayors for direct executive action, litigation in the state and federal courts, or grassroots mobilization on popular referenda and ballot initiatives. These numerous institutional venues foster various advocacy strategies. How and why do interest groups target different venues to achieve their objectives? What factors affect an interest group's capacity to act within, and thus its subsequent targeting of, particular institutional venues to pursue social reform?
Has Polling Enhanced Representation? Unearthing Evidence from the Literary Digest Issue Polls
Authors: Karol David
Published: May 2007

How has representation changed over time in the United States? Has responsiveness to public opinion waxed or waned among elected officials? What are the causes of such trends as we observe? Scholars have pursued these crucial questions in different ways. Some explore earlier eras in search of the “electoral connection”, i.e. the extent to which voters held office-holders accountable for their actions and the degree to which electoral concerns motivated politicians' behavior. Others explore the effects of institutional changes such as the move to direct election of senators or the “reapportionment revolution.”
Overview of the Metrological Scanning Probe Microscopes at PTB
Authors: Danzebrink H. U. , Dai G. , Pohlenz F. , Wilkening G.
Published: May 2007

Quantitative dimensional measurements of micro- and nanometre-sized
structures are urgently required from science and industry. Due to their
very high vertical resolution (down to sub nanometres) and high lateral
resolution (<10 nm) scanning probe microscopes (SPMs) are of great
interest for such metrological applications. Additionally, SPM methods
are able to measure surfaces in a number of modes like contact,
intermittent-contact and non-contact mode. The forces between tip and
sample are low during the measurement and, even in contact mode, reach
only a few nanonewtons. This fact prevents scratching of the measured
surface during the SPM scanning procedure even when very sharp tips are
used.
Nanolithograhpy Using Tip-Sample Material Transport Process
Authors: da Silva M. I. N. , Neves B. R. A.
Published: May 2007

Scanning Probe Microscopy (SPM) [1] has been an important tool to
organize matter on the nanometer scale. It has been proved to be a
powerful tool not only for imaging but also for nanofabrication.
SPM-based nanofabrication comprises manipulation of atoms or molecules
and SPM-based nanolithography. SPM-based nanolithography, referred to as
scanning probe lithography (SPL) holds good promise for fabrication of
nanometer-scale patterns as an emerging generic lithography technique
that employs SPM to directly pattern nanometer-scale features under
appropriate conditions. The water meniscus formation between the tip and
the flat substrate, due to the water layer present on any surface of a
material at ambient conditions, has been studied experimentally and
theoretically [2-6] using SPM techniques. The water effect in the
imaging process is well understood [2, 4, 6-8]. Dip pen nanolithogaphy
(DPN) [9] is one example of a technique that uses the water effect to
transfer material from the tip onto sample surface in direct-write
fashion with nanoscopic resolution.
Chemical Etching Tip Processing for Magneto-Optical Scanning
Near-Field Optical Microscopy
Authors: Schoenmaker J. , Pojar M. , Barra-Barrera A. D. , Seabra A. C. , Santos A. D.
Published: May 2007

Nanoscale resolution in microscopy characterization has become crucial
for state-of-the-art science and technology. We have developed a
Magneto-optical Scanning Near-Field Optical Microscope (MO-SNOM), and it
has demonstrated to be a powerful tool to study local magnetic
properties [1,2]. One of the critical steps in producing a reliable
instrument and consistent images is the fabrication of the microscope
tip. This work presents concepts and results on tip processing by
chemical etching on FS-SN-3224 optical fibers from 3M. The quality of
the tips produced was tested on magnetic multilayers presenting
exchange-bias coupling.
Anodic Oxidation Nanolithography on Semiconductors and Metallic
Films: Possibilities and Limitations
Authors: Silva-Pinto E. , Barboza A. P. M. , Neves B. R. A.
Published: May 2007

One of the pillars of Nanotechnology is the possibility of matter
manipulation on nanometer scale. At the basis of such pillar, the
importance of Scanning Probe Microscopy (SPM) is twofold: surface
visualization and material manipulation at a sub-molecular level. There
is a myriad of reports in the literature showing astonishing cases of
high resolution imaging and manipulation carried out by different SPM
techniques [1]. Within such examples, anodic oxidation nanolithography
(AON) appears as one of the most promising tools due to its simplicity
and applicability to a large variety of materials [1,2]. Therefore, this
work reports on a detailed study of possibilities and limitations of AON
towards the fabrication of semiconductor- and/or metal-based devices.
AFM Imaging of Encapsulated Spondylosium panduriforme Alga
Authors: Freire-Nordi C. S. , Taciro S. , Bernardes-Filho R. , Parizotto N. A. , Vieira A. A. H. , Nascimento O. R.
Published: May 2007

Some microalga species may accumulate extracellular polysaccharides,
such as a gelatinous mass that encloses its cells, and is known as
envelopes, sheaths or capsules. These structures are very common among
the Desmidiales. However, studies concerning their functions, properties
and structures are still incipient. Spondylosium panduriforme is a
filamentous desmids, enclosed by a great and continuous capsule with
well-defined borders firmly bond to the cell. These characteristics can
be observed through light microscopy in Indian ink preparations. The S.
panduriforme capsule is taken as an essential part of the cell, and
points out the importance of this structure for its proper functioning
[1,2].
Evaluation of Red Blood Cells of Healthy Subjects and Patients with
Myelodysplastic Syndrome
Authors: Costa E. F. , Magalhaes S. M. M. , Pitombeira M. S. , Freire J. A. K. , Freire V. N. , Barreto M. S. F. , Rebelo L. M. , Santos R. P. , Farias G. A.
Published: May 2007

Atomic Force Microscopy (AFM) is a recent technique that allows
evaluation of features in biological systems that could not be
previously observed by other instruments. Red Blood Cells (RBC) have
been extensively studied because of their relatively simple membrane
structure, convenience of preparation and scanning [1]. As an ancillary
way of confirming diagnoses, AFM has mostly been used to determine shape
and size of RBCs, which are important indicators of some blood diseases
or disordered erythropoiesis [2]. In Myelodysplastic Syndrome (MDS)
hematopoiesis is inefficacious with consequent anemia that may evolve to
acute leukemia. Genomic alterations lead to structural defects in the
biomolecular network that forms the erythrocyte membrane. The
deformation capability of the cells and their lifetime in circulation
are diminished [5]. AFM allows us to observe in a controlled way the
response of these membrane molecular networks under physical and
chemical stimuli in many different physiological conditions, such as in
air and liquids [6]. Using this technique, many new characteristics have
been found in erythrocyte membranes that are still of undetermined
significance [3,4]. The aim of our work is to compare membrane
morphology of two groups of blood donors, that is, healthy subjects and
patients with MDS. The images yielded by AFM confirm the structure of
the erythrocytes and reveal interesting submicron features on the cell,
suggesting a way to distinguish between RBCs from healthy donors and
RBCs from patients with MDS.
Adsorption Behavior of Concanavalin A onto Thin Solid Films
Authors: de Castro L. B. R. , Heinze T. , Petri D. F. S.
Published: May 2007

Ultrathin films of polysaccharides provide convenient conditions for the immobilization of
biomolecules, promoting the development of biosensors supported on renewable sources [1-3].
Specific interactions such as protein-substrate, antigen-antibody and lectin-carbohydrate can be used
with advantage for the creation of biotechnological devices.
Sporopollenin Nanostructure of Ilex paraguariensis A.St.Hil Pollen
Grains
Authors: Santos R. P. , Rebelo L. M. , Costa E. F. , Santiago A. A. X. , Freire V. N. , Freire J. A. K. , Farias G. A. , Oliveira T. M. , Bezerra G. A. , Cavada B. S.
Published: May 2007

Pollens appear like a fine to coarse powder that is liberated by the
microsporangia of Gimnosperms and Angiosperms. The pollen grain wall,
the sporoderm, envelopes the microgametophytes (male gametophytes),
which produce the male gametes of seed plants. Pollen grains are
interesting from the material science point of view since the native
polymer, the sporopollenin, found in the sporoderm outer layer (exine),
is one of the toughest known materials which is degraded by oxidation
but is resistant to reduction. This property permits the sporopollenin
persistence as an unaltered polymer in sediments of great age, e.g the
Ordovician period, 400 million years ago. Sporopollenin is a mixture of
fatty acids, phenyl-derivatives as p-coumaric acid, and carotenes [1].
Its nanostructure is not yet completed revealed. Therefore, more studies
must be performed. A number of models have been proposed for the
sporopollenin nanostructure of spores and pollen grains [2]. Rowley et
al. [3-4] interpret exine structure as being formed by helical subunits,
based on transmission and scanning electron microscope (TEM and SEM)
studies. The atomic force microscopy (AFM) is the ideal method to study
the sporopollenin nanostructure [5] since the arrangement of components
is not visualized easily through other microscope techniques (e.g. TEM
and SEM). In the present work, we used AFM to study the sporopollenin
nanostructure of the Ilex paraguariensis A.St.Hil. exine, an Angiosperm
(Aquifoliaceae).