bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural differences exhibited by networks prepared by chemical or photochemical reactions II — Thermoelastic properties
Authors: Haidar Bassel , Vidal Alain , Donnet Jean‐Baptiste
Published: April 2007

Thermoelastic properties and swelling measurements were used to characterise networks obtained either by peroxide curing or by photocrosslinking.

In agreement with previous studies, it was shown, on the one hand that the measured value of the average molecular weight of a network strand (Mc) depends on its method of determination and that the ratio McT/Mcv2m is a characteristic of each crosslinking process, on the other hand photo‐crosslinked materials exhibit a more homogeneous distribution of the crosslink points than do peroxide cured samples.

Important parameters such as fe/f, the energetic contribution to the equilibrium retractive force, and d In < r2> 0/dT, the temperature coefficient of the unperturbed dimension of the macromolecular chain, were determined.
Matrix polymerisation of poly(vinylacetate)
Authors: Bezdadea Mariana , Uglea Constantin , Agherghinci Ion
Published: April 2007

The matrix polymerisation of poly(vinylacetate) was investigated. Using scanning electron microscopy and gel permeation chromatography, the morphology and molecular weight distribution of poly(vinylacetate) were determined. The experimental data prove the matrix influence upon the molecular and morphological characteristics of poly(vinylacetate) thus obtained.
Mechanism of reaction of cyanogen bromide‐activated agarose with amines and the solvolysis of amine ligands
Authors: Kennedy John F. , Barnes Junor A. , Matthews John B.
Published: April 2007

Cyanogen bromide activated agarose is widely employed as the water‐insoluble matrix in immunoadsorption and affinity chromatography for the immobilisation of proteins. A reaction mechanism is presented for the cyanogen bromide activation of the galactan, agarose, the coupling of model amines to the activated carbohydrate matrix and the detachment of ligands. Dansyl (Dns) derivatisation of the acid hydrolysed and unhydrolysed amine derivatives resulting from the reaction of cyanogen bromide‐activated Sepharose® and N‐α‐acetyl‐L‐ornithine reveal the production of arginine, indicating that the amine‐Sepharose conjugate is an O‐substituted isourea. Thin layer chromatography of the Dns‐derivatised unhydrolysed filtrate from the reaction indicated the formation of several derivatives which suggest that the isourea bonds can be cleaved by the solvolytic attack of nucleophiles in the pH range 8–9.5. Nucleophilic attack by amino groups on the amine‐Sepharose conjugates releases N‐monosubstituted guanidine, N1, N2 disubstituted ornithine and substituted ureas.
Lysosomal‘acid’ hydrolases in normal individuals controls and patients with inborn errors of metabolism
Authors: Raine D. Noel , Crossley Jane E. , Kennedy John F.
Published: April 2007

Using commercially available artificial substrates, a number of lysosomal‘acid’ hydrolases in plasma, leucocytes and cultured skin fibroblasts from normal individuals, controls and patients with inborn errors of metabolism affecting lysosomal enzymes have been investigated. The pH optima, Km values and temperature‐activity profiles are reported, but some of the physiochemical parameters of the catalytic properties of the normal enzymes are not those that would be expected for mammalian system. Temperature optima of α‐L‐fucosidase, α‐L‐iduronidase, sphingomyelinase and β‐D‐glucuronidase were different in different sources and differences were seen in different enzymes from the same source. Only sphingomyelinase in leucocytes and α‐L‐iduronidase in leucocytes and fibro‐blasts showed maximum activity at 37°C, with other enzymes showing an unusually high optimum of 50°C or greater. Lysosomal enzymes from patients with inborn errors of metabolism showed maximum activity at the same temperature as observed in normal individuals with the exception of α‐L‐fucosidase, β‐D‐glucuronidase and α‐N‐acetyle‐D‐glucosaminidase in plasma from a patient with mucolipidosis II and β‐D‐glucuronidase in plasma from a patient with mucopolysaccharidosis type IIIA.
Methods of Following Drug Release from Controlled Release Dosage Forms
Authors: Gould Philip L.
Published: April 2007

Many new polymeric controlled release drugs delivery systems are currently being marketed. The cornerstone for the development of these new drug presentations is in vitro release testing. This paper outlines the design conditions for such release systems, and factors such as drug solubility, solution diffusivitiy and hydrodynamics, as well as in vitro‐in vivo correlations are discussed. The two main approaches to in vitro release system design are then outlined; the closed rotational systems and the open flow systems.
Electroinitiated and radiation‐induced polymerisation of epoxycyclohexane
Authors: Akbulut Ural , Önal Ahmet M. , Usanmaz Ali , Toppare Levent K.
Published: April 2007

Liquid‐state radiation‐induced and electroinitiated polymerisations of epoxycyclohexane (ECH) have been investigated. The effect of temperature on the electroinitiated polymerisation rate was also studied. The decrease in monomer concentration during polymerisation was followed by gas chromatographic analysis of electrolysis solutions. The i.r. spectra of the polymers suggested polyether structure. N.m.r. spectra of products indicate that the polymerisation of ECH propagates through the opening of the epoxy rings. Poly(epoxycyclohexane) obtained by both methods are amorphous according to X‐ray analyses.
Radiation‐induced and electroinitiated polymerisation of 1, 2‐Epoxy‐4‐epoxyethylcyclohexane
Authors: Onal Ahmet M. , Usanmaz Ali , Akbulut Ural , Toppare Levent
Published: April 2007

Liquid state radiation‐induced and electroinitiated cationic polymerisation of 1,2‐epoxy‐4‐epoxyethylcyclohexane (EECH) have been investigated. Soluble and cross‐linked polymers were obtained during the radiation‐induced polymerisation of EECH, depending upon the radiation dose. Electroinitiated polymerisation of the monomer yielded cross‐linked polymers on the surface of the anode. The expected polyether structure was observed for i.r. data. The polymerisation propagates via opening of the epoxy rings as indicated by n.m.r. spectra. X‐Ray analyses showed that the products obtained by both methods are amorphous.
Spectroscopic studies of undoped and doped polystyrene films
Authors: Talway I. M. , Sinha H. C. , Srivastave A. P.
Published: April 2007

Spectroscopic (i.r., u.v.) studies of undoped polystyrene and that doped with Acrylic Acid films (30μ thick), prepared by isothermal immersion technique, have been reported. It is found that in the case of i.r. spectra an additional absorption peak appears near 1420cm−1, whereas those present near 1300 and 980cm−1, as shoulders in the undoped sample, appear as sharp peaks in the doped samples. In the region 3300–2500cm−1 a broadening appears in the doped films which increases with the dopant concentration. In the case of u.v. spectra, out of four absorption regions present in the undoped films two bands merge and only three appear in the doped ones. The u.v. absoption increases with the dopant concentration. These results have been explained on the basis of a charge transfer complex formation due to the interaction between the dopant and the polymer matrix.
Studies in heterocyclic polymers Pt VII synthesis and polymerisation of the monomer benzobis (aminoiminopyrrolenine) and synthesis of benzobis (diphenylpyrrolenine)
Authors: Hussain Mohammad , Hodd Kenneth A.
Published: April 2007

Pyromellitonitrile (1,2,4,5—tetracyanobenzene) and ammonia were reacted under optimum conditions to produce a monomer benzobis (aminoiminopyrrolenine) in high yield. The structure of benzobis (aminoiminopyrrolenine) was established by preparing its derivative pyromellitic diimide, and by infrared and elemental analysis. Benzobis (aminoiminopyrrolenine) was also reacted with aniline to produce a benzobis (diphenylpyrrolenine), a greenish yellow pigment. This monomer benzobis (aminoiminopyrrolenine) was further reacted with 4,4‐diaminodiphenyl ether to give linear and macrocyclic polymers.
A simple 1H N.m.r. Method for the quantitation of O‐acetate ester and pyruvic acid acetal content of polymeric xanthan gum and related polysaccharides
Authors: Kennedy John F. , Stevenson David L. , White Charles A. , Tolley Malcolm S. , Bradshaw Ian J.
Published: April 2007

Traditional methods for the quantitation of O‐acetate ester and pyruvic acid acetal in xanthan gums require hydrolysis procedures followed by determination of acetic acid and pyruvic acid separately either by colorimetric, enzymic or chromatographic assays. Some of these assays are time‐consuming and involve many solvent extractions, and during the course of these procedures the xanthan sample is destroyed by hydrolysis. The methyl protons of both O‐acetate ester and pyruvic acid acetal can be detected by 1H n.m.r. spectroscopy, and this paper describes a method for the quantitative determination of these groups on intact polymeric xanthan using an internal integration standard dissolved within the sample. The method is non‐destructive, can be easily performed on a 60MHz spectrometer equipped with Fourier Transformation and variable temperature control, and simultaneously quantitates both O‐acetate ester and pyruvic acid acetal with improved accuracy.
Morphology of poly(hexamethylene oxide) fractions
Authors: Marco Carlos , Fatou José G. , Bello Antonio , López Angeles
Published: April 2007

The supermolecular structure of crystallised molecular weight fractions of poly(hexa‐methylene oxide), covering the molecular weight range (M) 4.5. × 103 to 8. 5 × 104, was studied by polarised light microscopy and small angle light scattering. Different forms were observed as a function of molecular weight and crystallisation temperatures. Perfect spherulites are formed after rapid crystallisation, and these forms deteriorate as both the molecular weight and crystallisation temperature increase. The morphology in the isothermal crystallisation region corresponds to an intermediate state which represents a transition from spherulites to hedrites.
Effects of applied potential on electroinitiated copolymerisation of α‐methylstyrene and β‐bromostyrene
Authors: Toppare Levent , Eren Sami , Akbulut Ural
Published: April 2007

Electroinitiated cationic copolymerisation of α‐methylstyrene and β‐bromostryene has been studied at various applied potentials. The relationship between copolymerisation potential and resulting copolymer composition was investigated. The advantages of employing constant potential electrolysis over constant current electrolysis are discussed in terms of the reactivity ratios. The reactivity ratios of the monomers are calculated according to the integrated Lewis‐Mayo equation.
Correlation between the cellulose fibres beating and the fixation of a soluble cationic polymer
Authors: Rouger J. , Mutje P.
Published: April 2007

The amount of cationic soluble polymer fixed by cellulose fibres, whose specific surface area is increased by beating, was determined by a colloidal titration method. A linear relationship between the polymer uptake and the surface density of carboxyl groups was obtained up to a beating degree of 54°SR. For higher values, the uptake was found to be independent of surface carboxyl groups. These results are interpreted in terms of two mechanisms: a fixation of polycations through an ion‐exchange mechanism and an adsorption of polymer by Van der Waals interactions and/or hydrogenbonding.
A rapid method for the assay of alginates in solution using polyhexamethylenebiguanidinium chloride
Authors: Kennedy John F. , Bradshaw Ian J.
Published: April 2007

A rapid method for the quantitative assay of alginate in solution over a wide concentration range (0.01–0.5 percent) has been developed using the polymetric cation poly(hexamethylenebiguandinium chloride) [PHMBH+Cl−]. The procedure consists of the addition of a known excess amount of PHMBH+Cl− to alginate solutions to precipitate the sample quantitatively and therafter measuring the u.v. absorption of residual PHMBH+C1− in the supernatant. The working range of the assay can be altered by simply adjusting the excess quantity of PHMBH+Cl− which is added during the assay. Assay response is easily reproducible and insensitive to variation in salt concentration (up to 2.5 per cent), pH (5.5–7.6) and temperature (10–60°C). The PHMBH+Cl− method shows good agreement with another recognised method for the assay of alginate solutions. The simplicity of this new method and the short time required to perform it, enhances its suitability as a quick analytical procedure for alginates. Preliminary evidence suggests that assay response is independent of the D‐mannuronic acid/L‐guluronic acid ratio of alginate.
Electroinitiated and radiation‐induced polymerisation of epoxycyclopentane
Authors: Onal Ahmet M. , Usanmaz Ali , Akbulut Ural , Toppare Levent
Published: April 2007

Liquid state radiation‐induced and electroinitiated polymerisations of epoxycyclopentane (ECP) have been investigated. Dichloromethane and tetrabutylammonium hexafluoro‐phosphate were employed as a solvent electrolyte couple. Temperature effects on the rate of electroinitiation were also studied. Apparent activation energy for the electroinitiated polymerisation was calculated from the Arrhenius plot. The propagation of the polymerisation for both methods was found to be through the opening of the epoxy ring, as verified by i.r. and n.m.r. spectra. Both methods of polymerisation yielded tacky, amorphous polymers.
Polydienes possessing terminal ionic groups part 1 preparation of polydienes with terminal quaternary ammonium groups
Authors: Richard D. H. , Service D. M. , Stewart M. J.
Published: April 2007

Methods are described by which living anionic polydienes are reacted with α, ω‐alkylene‐chloroamines to generate polymers possessing terminal tertiary amine groups. Subsequent reaction with alkyl halides yields materials with quaternary ammonium terminal ligands. Evidence is presented to show that both reaction steps proceed with high efficiency, so that overall conversion is virtually quantitative.

The ionically terminated polydienes exhibit two phase morphology, and the difunctional materials have thermoplastic elastomeric properties.
The trimethylsilylation of sodium silicate. Dependence of yield and molecular weight of the product on various mixing methods
Authors: Kajiwara M. , Yamamoto N.
Published: April 2007

The trimethylsilylation of sodium silicate in solution was carried out using magnetic and ultrasonic mixing. The maximum yield of trimethylsilylated product was obtained by magnetic stirring. The product having the higher molecular weight was formed using ultrasonic as well as magnetic mixing. The product was a white amorphous solid, soluble in most organic solvents.
Experimental control and threats to internal validity of concurrent and nonconcurrent multiple baseline designs
Authors: Christ Theodore J.
Published: April 2007

Single‐case research designs are often applied within school psychology. This article provides a critical review of the scientific merit of both concurrent and nonconcurrent multiple baseline (MB) designs, relative to their capacity to assess threats of internal validity and establish experimental control. Distinctions are established between AB replications and nonconcurrent multiple baseline designed studies using the initial conception proposed by P.J. Watson and E.A. Workman (1981). Despite some previously pessimistic evaluations of nonconcurrent multiple baseline designs, the findings of this review suggest that various threats of internal validity can be assessed and ruled out using either concurrent or nonconcurrent MB designs. It seems that nonconcurrent designs can be used to assess the intervening effects of history, but might be more prone to threats of mortality. These and other threats of internal validity are reviewed and recommendations are provided. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 451–459, 2007.
Dealing with assumptions underlying statistical tests
Authors: Wells Craig S. , Hintze John M.
Published: April 2007

The validity of a hypothesis test is partly determined by whether the assumptions underlying the test are satisfied. In the past, a preliminary analysis of the data has been suggested prior to the use of the statistical test. In this article, the authors describe several limitations of preliminary tests (e.g., influence on significance levels). Another strategy that uses theoretical knowledge in conjunction with prior empirical evidence and reason, prior to data collection, is described. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 495–502, 2007.
Statistical reform in school psychology research: A synthesis
Authors: Swaminathan Hariharan , Rogers H. Jane
Published: April 2007

Statistical reform in school psychology research is discussed in terms of research designs, measurement issues, statistical modeling and analysis procedures, interpretation and reporting of statistical results, and finally statistics education. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 543–549, 2007.
Coating lysozyme molecularly imprinted thin films on the surface of microspheres in aqueous solutions
Authors: Yan Chang‐Ling , Lu Yan , Gao Shu‐Yan
Published: April 2007

The polymerization of 3‐aminophenylboronic acid in an aqueous environment was used for the first time to modify polystyrene microspheres for protein (lysozyme) molecular imprinting. Polystyrene microspheres were prepared by styrene polymerization in an aqueous emulsion with poly(vinyl alcohol) as a surfactant. Poly(3‐aminophenylboronic acid) was then grafted onto the surface of the polystyrene microspheres through oxidation by ammonium persulfate in an aqueous solution in the presence or absence of lysozyme or hemoglobin. Rebinding experiments were conducted to establish the equilibrium time and to detect the specific binding capacity and selective recognition. The results indicated that the microspheres, imprinted by the template protein lysozyme or hemoglobin, possessed specific recognition sites on the shells and had a high specific binding capacity for template proteins. The imprinted particles did not need to be ground or sieved and could easily reach the adsorption equilibrium, thus avoiding some problems of the bulk polymer. All these results demonstrate that the particles have potential applications as substitutes for bulk polymers in biological macromolecular affinity studies. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1911–1919, 2007
Principles of nanostructure design with protein building blocks
Authors: Tsai Chung‐Jung , Zheng Jie , Zanuy David , Haspel Nurit , Wolfson Haim , Alemán Carlos , Nussinov Ruth
Published: April 2007

Currently there is increasing interest in nanostructures and their design. Nanostructure design involves the ability to predictably manipulate the properties of the self‐assembly of autonomous units. Autonomous units have preferred conformational states. The units can be synthetic material science‐based or derived from functional biological macromolecules. Autonomous biological building blocks with available structures provide an extremely rich and useful resource for design. For proteins, the structural databases contain large libraries of protein molecules and their building blocks with a range of shapes, surfaces, and chemical properties. The introduction of engineered synthetic residues or short peptides into these can expand the available chemical space and enhance the desired properties. Here we focus on the principles of nanostructure design with protein building blocks. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Scoring function accuracy for membrane protein structure prediction
Authors: Gao Cen , Stern Harry A.
Published: April 2007

We perform a systematic examination of the ability of several different high‐resolution, atomic‐detail scoring functions to discriminate native conformations of loops in membrane proteins from non‐native but physically reasonable, or “decoy,” conformations. Decoys constructed from changing a loop conformation while keeping the remainder of the protein fixed are a challenging test of energy function accuracy. Nevertheless, the best of the energy functions we examined recognized the native structure as lowest in energy around half the time, and consistently chose it as a low‐energy structure. This suggests that the best of present energy functions, even without a representation of the lipid bilayer, are of sufficient accuracy to give reasonable confidence in predictions of membrane protein structure. We also constructed homology models for each structure, using other known structures in the same protein family as templates. Homology models were constructed using several scoring functions and modeling programs, but with a comparable sampling effort for each procedure. Our results indicate that the quality of sequence alignment is probably the most important factor in model accuracy for sequence identity from 20–40%; one can expect a reasonably accurate model for membrane proteins when sequence identity is greater than 30%, in agreement with previous studies. Most errors are localized in loop regions, which tend to be found outside the lipid bilayer. For the most discriminative energy functions, it appears that errors are most likely due to lack of sufficient sampling, although it should be stressed that present energy functions are still far from perfectly reliable. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Computational analysis of the S. cerevisiae proteome reveals the function and cellular localization of the least and most amyloidogenic proteins
Authors: Tartaglia Gian Gaetano , Caflisch Amedeo
Published: April 2007

Protein sequences have evolved to optimize biological function that usually requires a well‐defined three‐dimensional structure and a monomeric (or oligomeric) state. These two requirements may be in conflict as the propensity for β‐sheet structure, which is one of the two most common regular conformations of the polypeptide chain in folded proteins, favors also the formation of ordered aggregates of multiple copies of the same protein (fibril, i.e., polymeric state). Such β‐aggregation is typical of amyloid diseases that include Alzheimer's, Parkinson's, and type II diabetes as well as the spongiform encephalopaties. Here, an analytical model previously developed for evaluating the amyloidogenic potential of polypeptides is applied to the proteome of the budding yeast (Saccharomyces cerevisiae). The model is based on the physicochemical properties that are relevant for β‐aggregation and requires only the protein sequence as input. It is shown that β‐aggregation prone proteins in yeast are accrued in molecular transport, protein biosynthesis, and cell wall organization processes while they are underrepresented in ribosome biogenesis, RNA metabolism, and vitamin metabolism. Furthermore, β‐aggregation prone proteins are much more abundant in the cell wall, endoplasmic reticulum, and plasma membrane than in the nucleolus, ribosome, and nucleus. Thus, this study indicates that evolution has not only prevented the selection of amyloidogenic sequences in cellular compartments characterized by a high concentration of unfolded proteins but also tried to exploit the β‐aggregated state for certain functions (e.g. molecular transport) and in well‐confined cellular environments or organelles to protect the rest of the cell from toxic (pre‐)fibrillar species. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Rotigotine: first dopamine agonist transdermal patch
Authors: Metta Vinod , Muzerengi Sharon , Chaudhuri K Ray
Published: April 2007

Rotigotine (Neupro) is the first dopamine agonist skin patch to become available. Our New products review considers the clinical‐trial evidence for its efficacy and tolerability in the treatment of early and advanced Parkinson's disease. Copyright © 2007 Wiley Interface Ltd
Nongenital warts: recommended approaches to management
Authors: Shankar Sonal , Sterling Jane
Published: April 2007

Although warts usually resolve sponta neously in time, patients often request treat ment due to discomfort or their appearance. Our Drug review considers the properties and efficacy of the many treatments avail able, followed by sources of further informa tion and the Datafile. Copyright © 2007 Wiley Interface Ltd
Fluorescence analysis of dissolved organic matter in natural, waste and polluted waters—a review
Authors: Hudson Naomi , Baker Andy , Reynolds Darren
Published: April 2007

Dissolved organic matter (DOM) in aquatic systems originates from a range of sources. Some is allochthonous, transported from the surrounding landscape to the water body, and is derived from and influenced by the geology, land use and hydrology of its origin. Some is created in situ through microbial activity, which may provide an independent source of organic matter, or a recycling mechanism for that which has been transported into the water body. The relative contribution of each source depends upon the location and environmental conditions within and without the water body. Human activity is also a source of DOM, much of which is believed to be labile, which can enter the aquatic system through direct point discharges, diffuse leaching and aerial dispersal. Fluorescence spectroscopy can provide an excellent tool to source DOM fractions, and to monitor and understand DOM transformations in aquatic systems, as much DOM has an intrinsic fluorescence. In particular, recent advances in optical technology, enabling rapid investigation of shorter wavelengths, have enabled more detailed characterization of organic material and its reactions in water. In this article, we review the use of fluorescence spectroscopic techniques to measure the intrinsic fluorescence of organic matter and the application of fluorescent DOM analysis in marine waters, freshwaters and wastewaters. Copyright © 2007 John Wiley & Sons, Ltd.
Atomic simulation of the point defects in three low‐index surfaces of BCC transition metals with the MAEAM
Authors: Zhang Jian‐Min , Wen Yan‐Ni , Xu Ke‐Wei
Published: April 2007

The favorable position of an adatom and the formation energies of a single vacancy and an adatom‐vacancy pair in three low‐index surfaces of body‐centered cubic (BCC) transition metals have been calculated by using the modified analytical embedded atom method (MAEAM). The favorable position of an adatom is at the fourfold and twofold positions above the (100) and (110) surfaces respectively, but it is deviated $(3 - \sqrt{6})a/3$ from the threefold position of the (111) surface. Either the heights of the adatom from the top atomic layer, or the formation energies of a single vacancy, or an adatom‐vacancy pair decrease in sequence of the (110), (100) and (111) surfaces for each metal. Furthermore, the formation energy of an adatom‐vacancy pair is always lower than that of a single vacancy for each low‐index surface of each metal, which shown the formation of adatom‐vacancy pair is more energetically favorable than the vacancy for the BCC transition metals. Copyright © 2007 John Wiley & Sons, Ltd.
How national systems differ in their constraints on corporate executives: a study of CEO effects in three countries
Authors: Crossland Craig , Hambrick Donald C.
Published: April 2007

Do CEOs matter more in some countries than in others? Based on a theoretical consideration of three fundamental national‐level institutions—national values, prevailing firm ownership structures, and board governance arrangements—we argue that CEOs in different countries face systematically different degrees of constraint on their latitudes of action, and hence they differ in how much effect they have on firm performance. To test these ideas, we apply a variance components analysis methodology to 15‐year matched samples of 100 U.S. firms, 100 German firms, and 100 Japanese firms. Results provide strong, robust evidence that the effect of CEOs on firm performance—for good and for ill—is substantially greater in U.S. firms than in German and Japanese firms. Copyright © 2007 John Wiley & Sons, Ltd.
Practical testing of a C99 compiler using output comparison
Authors: Sheridan Flash
Published: April 2007

A simple technique is presented for testing a C99 compiler, by comparing its output with the output from pre‐existing tools. The advantage to this approach is that new test cases can be added in bulk from existing sources, reducing the need for in‐depth investigation of correctness issues and for creating new test code by hand. This technique was used in testing the PalmSource Palm OS® Cobalt ARM C/C++ cross‐compiler for Palm‐Powered® personal digital assistants, primarily for standards compliance and the correct execution of generated code. The technique described here found several hundred bugs, mostly in our in‐house code, but also in longstanding high‐quality front‐ and back‐end code from Edison Design Group and Apogee Software. It also found 18 bugs in the GNU C compiler, as well as a bug specific to the Apple version of GCC, a bug specific to the Suse version of GCC, and a dozen bugs in versions of GCC for the ARM processor, several of which were critical. Copyright © 2007 John Wiley & Sons, Ltd.
When to use splay trees
Authors: Lee Eric K. , Martel Charles U.
Published: April 2007

In this paper we present new empirical results for splay trees. These results provide a better understanding of how cache performance affects query execution time. Our results show that splay trees can have faster lookup times compared with randomly built binary search trees (BST) under certain settings. In contrast, previous experiments have shown that because of the instruction overhead involved in splaying, splay trees are less efficient in answering queries than randomly built BSTs—even when the data sets are heavily skewed (a favorable setting for splay trees). We show that at large tree sizes the difference in cache performance between the two types of trees is significant. This difference means that splay trees are faster than BSTs for this setting—despite still having a higher instruction count. Based on these results we offer guidelines in terms of tree size, access pattern, and cache size as to when splay trees will likely be more efficient. We also present a new splaying heuristic aimed at reducing instruction count and show that it can improve on standard splaying by 10–27%. Copyright © 2007 John Wiley & Sons, Ltd.
Clock synchronization for distributed media applications
Authors: Distler Thomas James , Ouyang Jinsong
Published: April 2007

Current video wall technology relies on custom processing hardware to drive the individual display channels. This hardware is both expensive to design and to maintain. Given that modern off‐the‐shelf computers have a significant amount of computing power, future video displays can be driven with this hardware at a lower cost. By using mass‐produced computers and a standard commercial operating system, the benefits of economies of scale can be brought to the custom video wall market. This paper describes a Windows library that provides the synchronized timing support necessary to drive a video wall with consumer hardware. The goal is to provide a key building block for the media software that will process the incoming video stream. This library exports several interfaces to the host software and provides support for synchronized timers, a synchronized clock, and reliable multicast messaging. The library uses common Windows APIs and protocols for maximum interoperability and portability. Through empirical testing, we are able to show that synchronization between any two machines in the system can be maintained to within 12 ms when run on Windows XP SP2. This synchronization is also shown to be consistent even when there is a heavy load on the processor. As a result, this library will successfully allow a commercial video wall to be driven from media software running on consumer hardware and software. Copyright © 2007 John Wiley & Sons, Ltd.
Who's right for an international assignment?
Authors: Fetterolf Cynthia
Published: April 2007

Picking the wrong candidate for an international assignment can be costly for both the individual and his or her company. So more and more companies are turning to testing techniques like the Overseas Assignment Inventory that allows a company to compare a candidate against a profile of success based on a study of thousands of international managers.
Europe and the joint venture frenzy
Authors: Goldenberg Susan
Published: April 2007

As the European community draws nearer to unifying its markets by 1992, smart American companies are entering into joint ventures with European firms. For these companies, digging a foothold into what will be the world's largest market is just too crucial to put off to a later date.
Financing international trade transactions
Authors: McVey Thomas B.
Published: April 2007

International trade transactions present unique commercial and legal risks, and hence specialized forms of financing are required.
The evolution of global strategy
Authors: Lei David , Slater Bob
Published: April 2007

Changes in technology, manufacturing, and marketing within an industry may necessitate a shift in the way an organization achieves competitive advantage on a global basis. Forewarned is forearmed.
Privatization in Eastern Europe: Opportunities and pitfalls
Authors: Judy Richard W.
Published: April 2007

More than 20 years of experience in Eastern Europe has proved that the only way to produce good organizational results is to put companies into the hands of real owners. That means privatization.
Low citrulline may not be diagnostic of ornithine transcarbamylase deficiency: A case report
Authors: Chiong M. A. , Carpenter K. , Christodoulou J.
Published: April 2007

A newborn boy with family history of severe ornithine transcarbamylase (OTC) deficiency was investigated prospectively and managed aggressively at birth based on an existing protocol for at risk neonates. Undetectable citrulline levels at birth suggested that the infant was affected; however, normal plasma glutamine and urine orotic acid levels confused the diagnosis to some extent. Mutation testing confirmed that the patient did not have OTC deficiency. Thus the low plasma citrulline level did not validate our initial biochemical suspicion of OTC deficiency, and this highlights the importance of considering all available clinical, biochemical and molecular evidence in determining disease status.
Diagnostic criteria for CRPS I: Differences between patient profiles using three different diagnostic sets
Authors: Perez Roberto S.G.M. , Collins Susan , Marinus Johan , Zuurmond Wouter W.A. , de Lange Jaap J.
Published: April 2007

Complex Regional Pain Syndrome type I (CRPS I) is an illness which usually occurs due to major or minor tissue injury to the extremities. Because a unique pathophysiological mechanism for CRPS I has not yet been established, the diagnosis is based on observation and measurement of clinical symptoms and signs. In this study, a comparison was made between three sets of diagnostic criteria (the IASP, Bruehl et al. and Veldman et al.) based on patient reports and physicians’ assessments of signs and symptoms associated with CRPS I, in 372 outpatients suspected of having CRPS I. Agreement between CRPS I diagnosis among the three sets was poor (κ‐range: 0.29–0.42), leading to positive CRPS I diagnoses according to Veldman et al.'s criteria in 218 cases (59%), according to the IASP in 268 cases (72%), and according to Bruehl et al. in 129 cases (35%). Significant differences in patient profiles were found between the diagnostic sets for the number of patients reporting continuing disproportionate pain, larger area affected than the initial trauma (both p<0.001), increase of symptoms due to exercise (p=0.009), edema (p=0.015), temperature asymmetry (p=0.015), hyperesthesia, allodynia (both p<0.001) and hyperalgesia (p=0.036). Similarly, significant differences emerged for physicians’ observations of hyperesthesia and allodynia (both p<0.001). Highest combined values of sensitivity (SE) and specificity (SP) for the strongest cases of presence (n=108) or absence (n=62) of CRPS I were found for reported hyperesthesia (SE+SP:165%), allodynia (160%), observed color asymmetry (162%), hyperesthesia (157%), temperature asymmetry (154%) and edema (152%). The lack of agreement between the different diagnostic sets for CRPS I and the different clinical profiles that result from it may lead to different therapeutic and study populations, hampering adequate treatment and scientific development for this illness. We propose explicit reference to diagnostic criteria used in studies, and registration in trials of a broad variety of CRPS I features, as used in this study, to make subgroup phenotyping and post hoc analyses based on different diagnostic criteria possible.
Exposing cryptic antibacterial activity in Cyt1Ca from Bacillus thuringiensis israelensis by genetic manipulations
Authors: Itsko Mark , Zaritsky Arieh
Published: April 2007

In an attempt to endow Cyt1Ca with Cyt1Aa‐like antibacterial activity, both derived from Bacillus thuringiensis subsp. israelensis, two amino acids were replaced, E117V and N125A, so as to raise the hydrophobicity of the corresponding region, considered to be the membrane‐active motif. The clones obtained included multiple repeats of VIEVLKSLLGIALA, corresponding to head‐to‐tail polymerization of the primer, translated in frame with Cyt1Ca. These versions of Cyt1Ca caused instant arrest in biomass growth and decreased viability upon expression in Escherichia coli. Multiple insertions of the non‐mutated motif VIEELKSLLGINLA into the polypeptide were also lethal. To expose toxicity of the latter motif in the original Cyt1Ca, cyt1Ca was appropriately truncated.
Submarine push moraine formation during the early Fennoscandian Ice Sheet deglaciation
Authors: Laberg J.S. , Eilertsen R.S. , Salomonsen G.R. , Vorren T.O.
Published: April 2007

The glacial history in the topographically confined paleo-ice stream drainage route of Vestfjorden, North Norway, was analysed based on bathymetric data, high-resolution seismology and 14C AMS-dated gravity cores. The inner part of the fjord is characterised by axial-parallel mega-scale lineations whereas the outer part is dominated by two marginal morainal bank systems. The Værøy (inner) and Røst (outer) marginal moraine systems comprise several transverse, zigzag-shaped ridges. Seismic records show thrusted and folded sediment blocks within the ridges. The landforms are inferred to reflect basal processes and the transition from warm-based (inner fjord) to cold-based (outer fjord) conditions, i.e. fast flow followed by basal freeze-on, sediment deformation and morainal bank formation. The moraines formed during the final part of two paleo-ice sheet re-advances. 14C AMS dating indicates a maximum age of 13.7 14C ka BP (16.2 cal ka BP) for the Røst system whereas the Værøy system is inferred to be slightly older than 12.5 14C ka BP (14.5 cal ka BP). This demonstrates that the northern part of the Fennoscandian Ice Sheet behaved in a much more dynamic way during the early deglaciation than previously assumed.
Amino acids and immune function
Authors: Li Peng , Yin Yu-Long , Li Defa , Woo Kim Sung , Wu Guoyao
Published: April 2007

A deficiency of dietary protein or amino acids has long been known to impair immune function and increase the susceptibility of animals and humans to infectious disease. However, only in the past 15 years have the underlying cellular and molecular mechanisms begun to unfold. Protein malnutrition reduces concentrations of most amino acids in plasma. Findings from recent studies indicate an important role for amino acids in immune responses by regulating: (1) the activation of T lymphocytes, B lymphocytes, natural killer cells and macrophages; (2) cellular redox state, gene expression and lymphocyte proliferation; and (3) the production of antibodies, cytokines and other cytotoxic substances. Increasing evidence shows that dietary supplementation of specific amino acids to animals and humans with malnutrition and infectious disease enhances the immune status, thereby reducing morbidity and mortality. Arginine, glutamine and cysteine precursors are the best prototypes. Because of a negative impact of imbalance and antagonism among amino acids on nutrient intake and utilisation, care should be exercised in developing effective strategies of enteral or parenteral provision for maximum health benefits. Such measures should be based on knowledge about the biochemistry and physiology of amino acids, their roles in immune responses, nutritional and pathological states of individuals and expected treatment outcomes. New knowledge about the metabolism of amino acids in leucocytes is critical for the development of effective means to prevent and treat immunodeficient diseases. These nutrients hold great promise in improving health and preventing infectious diseases in animals and humans.
Food chromium content, dietary chromium intake and related biological variables in French free-living elderly
Authors: Roussel Anne-Marie , Andriollo-Sanchez Maud , Ferry Monique , Bryden Noella A. , Anderson Richard A.
Published: April 2007

Trivalent chromium (Cr3+) is an essential trace element involved in insulin function. Cr deficiencies result in decreased insulin sensitivity, glucose intolerance and an increased risk of diabetes. Cr status decreases with age suggesting that the elderly may be at high risk of Cr deficiency. This study aimed to provide information about the Cr content of foods in France and the Cr intake in French free-living elderly. We measured the food Cr content and daily Cr intake of freely chosen diets for 3 d in twelve French free-living elderly people and their Cr excretion and plasma hormonal related variables, leptin, insulin and cortisol. Considering the relationship between insulin resistance and oxidative stress, we also determined plasma thiobarbituric acid reactive substance, thiol groups and total and reduced glutathione. Although these subjects had well-balanced diets, their daily Cr intakes did not reach the French recommendations. The low Cr intakes were due to the low Cr density of the foods. We found a negative correlation between Cr intakes and insulin, BMI and leptin.
Oropharyngeal and hypopharyngeal myxoma: case report and literature review
Authors: Ayache S , Chatelain D , Tramier B , Strunski V
Published: April 2007

Objectives: To describe the features of an oropharyngeal and hypopharyngeal myxoma.

Materials and methods: Case report of a 34-year-old patient operated upon for a dual-location tumour, and review of the literature.

Results: The myxoma is a rare tumour. Various head and neck locations have been described, but not (to our knowledge) a tumour in both the oropharynx and the hypopharynx. Multiple synchronous locations must be searched for, particularly regarding cardiac myxoma.

Conclusion: The myxoma is a rare, benign tumour, even rarer in the head and neck. Surgical treatment must be complete in order to avoid recurrences, and should be performed after assessment for cardiac involvement.
Probabilistic envelope curves for design flood estimation at ungauged sites
Authors: Castellarin Attilio
Published: April 2007

Castellarin et al. (2005) introduced the probabilistic regional envelope curves (PRECs) of flood flows and formulated an empirical estimator of the recurrence interval T associated with the PREC for M synthetic cross‐correlated and concurrent sequences of annual maxima with length n. In principle, a PREC can be used to estimate the T‐year flood (design flood) for any basin in a given region as a function of the catchment area alone. A number of fundamental issues hamper the construction of PRECs and the estimation of their T for historical regional samples of flood flows. Some of these issues are addressed by this study, which presents an algorithm for the application of the empirical estimator of T to historical annual maximum series of unequal length and assesses how the selection of a particular cross‐correlation formula and plotting position affects the accuracy of design flood estimates retrieved from PRECs (PREC flood quantiles). The reliability of the proposed algorithm and the accuracy of the flood quantiles are discussed through a comprehensive cross validation. The results show that the reliability of PREC flood quantiles for ungauged sites is comparable with the reliability of regional estimates produced by the application of the index flood approach. The results of the cross‐validation also show that the selection of a particular correlation formula or plotting position may produce biased PREC flood quantiles, and suggest that the accuracy of the approach could be significantly enhanced by relaxing the assumption that the design flood scales with catchment area alone.
Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation
Authors: Moore J. Keith , Doney Scott C.
Published: April 2007

Recent upward revisions in key sink/source terms for fixed nitrogen (N) in the oceans imply a short residence time and strong negative feedbacks involving denitrification and N fixation to prevent large swings in the ocean N inventory over timescales of a few centuries. We tested the strength of these feedbacks in a global biogeochemical elemental cycling (BEC) ocean model that includes water column denitrification and an explicit N fixing phytoplankton group. In the northern Indian Ocean and over longer timescales in the tropical Atlantic, we find strong stabilizing feedbacks that minimize changes in marine N inventory over timescales of ∼30–200 years. In these regions high atmospheric dust/iron inputs lead to phosphorus limitation of diazotrophs, and thus a tight link between N fixation and surface water N/P ratios. Maintenance of the oxygen minimum zones in these basins depends on N fixation driven export. The stabilizing feedbacks in other regions are significant but weaker owing to iron limitation of the diazotrophs. Thus Fe limitation appears to restrict the ability of N fixation to compensate for changes in denitrification in the current climate, perhaps leading the oceans to lose fixed N. We suggest that iron is the ultimate limiting nutrient leading to nitrogen being the proximate limiting nutrient over wide regions today. Iron stress was at least partially alleviated during more dusty, glacial times, leading to a higher marine N inventory, increased export production, and perhaps widespread phosphorus limitation of the phytoplankton community. The increased efficiency of the biological pump would have contributed to the glacial drawdown in atmospheric CO2.
UV limb‐scatter spectra of noctilucent clouds consistent with mono‐modal particle size distribution
Authors: von Savigny C. , Burrows J. P. , Rapp M.
Published: April 2007

Limb‐backscatter spectra of noctilucent clouds (NLCs) are retrieved from limb measurements made with the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) on the Envisat satellite. The spectral dependence of many hundred sun‐normalized NLC spectra measured during the 2005 NLC season in the northern hemisphere can be well approximated with a power‐law in the 240–300 nm spectral range. In particular, no spectral signatures indicative of the presence of a second particle mode at radii exceeding 200 nm are found, in contradiction to recent studies. The results presented are consistent with a mono‐modal NLC particle size distribution.
Recent trends in Arctic Ocean mass distribution revealed by GRACE
Authors: Morison James , Wahr John , Kwok Ron , Peralta‐Ferriz Cecilia
Published: April 2007

Measurements of ocean bottom pressure by the Gravity Recovery and Climate Experiment (GRACE) and new in situ bottom pressure measurements confirm the accuracy and utility of GRACE measurements in the Arctic Ocean. They reveal a declining trend in bottom pressure that corresponds to mass changes due to decreasing upper ocean salinities near the North Pole and in the Makarov Basin. The spatial distribution and magnitude of these trends suggest the Arctic Ocean is reverting from the cyclonic state characterizing the 1990s to the anticyclonic state that was prevalent prior to the 1990s.