bluuebunny/crossref_metadata_2025 huggingface dataset:
Gastric cancers in young and elderly patients show different genomic profiles
Authors: Buffart TE , Carvalho B , Hopmans E , Brehm V , Kranenbarg E Klein , Schaaij‐Visser TBM , Eijk PP , van Grieken NCT , Ylstra B , van de Velde CJH , Meijer GA
Published: November 2006

Although most gastric cancers occur in elderly patients, a substantial number of cases of this common disease occur in young patients. Gastric cancer is a heterogeneous disease at the genomic level and different patterns of DNA copy number alterations are associated with different clinical behaviour. The aim of the present study was to explore differences in DNA copy number alterations in relation to age of onset of gastric cancer. DNA isolated from 46 paraffin‐embedded gastric cancer tissue samples from 17 patients less than 50 years of age [median 43 (21–49) years] and 29 patients greater than or equal to 70 years of age [median 75 (70–83) years] was analysed by genome‐wide microarray comparative genomic hybridization (array CGH) using an array of 5000 BAC clones. Patterns of DNA copy number aberrations were analysed by hierarchical cluster analysis of the mode‐normalized and smoothed log2 ratios of tumour to normal reference fluorescence signal intensities using TMEV software, after which cluster membership was correlated with age group. In addition, supervised analysis was performed using CGH Multi‐array. Hierarchical cluster analysis of the array CGH data revealed three clusters with different genomic profiles that correlated significantly with age (p = 0.006). Cluster 1 mainly contained young patients, while elderly patients were divided over clusters 2 and 3. Chromosome regions 11q23.3 and 19p13.3 contributed most to age‐related differences in tumour profiles. Gastric cancers of young and old patients belong to groups with different genomic profiles, which likely reflect different pathogenic mechanisms of the disease. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Lack of effect of influenza immunisation on anticoagulant control in patients on long‐term warfarin
Authors: MacCallum Peter , Madhani Manisha , Mt‐Isa Shahrul , Ashby Deborah
Published: November 2006

Purpose

The effect of influenza vaccination on oral anticoagulant control is uncertain but important to establish since anticoagulants are widely used and most patients taking them are candidates for immunisation because of age or underlying cardiac disease. We therefore prospectively evaluated the effect of influenza vaccination on International Normalised Ratio (INR) control in patients on long‐term warfarin.

Methods

We undertook a prospective audit of patients on long‐term warfarin attending a single hospital anticoagulant clinic who reported receiving influenza vaccination within the 10 days prior to a clinic visit. We compared the stability of anticoagulant control in the 12 months prior to and 10 days after immunisation, restricting analysis to those patients whose warfarin dosage was unchanged before and after vaccination.

Results

Of 106 consecutive patients who reported receiving influenza vaccination within the 10 days prior to a clinic visit, results were evaluable in 78 because the dose of warfarin was unchanged before and after vaccination. Influenza immunisation had no apparent effect on anticoagulant control. No bleeding or thrombotic complications were reported.

Conclusions

Our findings suggest that it is not necessary to routinely monitor the INR more closely after influenza vaccination. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation on crosslinking behaviors of NBR/PVC filled with anhydrous copper sulfate particles by dynamic mechanical analysis
Authors: Shen Fei , Yuan Xiaofang , Wu Chifei
Published: November 2006

Crosslinking behaviors of acrylonitrile butadiene rubber (NBR)/poly (vinyl chloride) (PVC) alloy, filled with anhydrous copper sulfate (CuSO4) particles, were investigated for the first time by dynamic mechanical analysis (DMA) under hetero and isothermal modes, respectively. In the heterothermal testing, (NBR/PVC)/CuSO4 compound showed two marked increases in the storage modulus (E′), corresponding to coordination crosslinking of NBR‐CuSO4 and self‐crosslinking of NBR and PVC respectively. During the isothermal testing, a dramatic increase in E′ was found at the initial stage while that of original NBR/PVC alloy was not detected. The marked increase in E′ of (NBR/PVC)/CuSO4 compound was mainly due to the crosslinking induced by coordination between CN and Cu2+. The increasing extent of E′ increased with the rise of CuSO4 content, suggesting the formation of a greater number of crosslinks. Moreover, the activation energy (Ea) of crosslinking process was about 139 kJ/mol. In this work, fourier transform infrared spectrum (FT‐IR) and equilibrium swelling method were also performed for the characterization of the compound. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 41–51, 2007
Miscibility and morphology of poly(ethylhexylacrylate)/liquid crystal blends prepared under different conditions
Authors: Slimane Sofia Kara , Roussel Frédérick , Maschke Ulrich
Published: November 2006

A comparative study of the phase diagrams and morphology of blends of poly(2‐ethylhexylacrylate) and low molecular weight liquid crystals (LCs) prepared under different conditions is presented. Two LCs are used; one is the 4‐cyano‐4′‐n‐pentyl‐biphenyl and the other is the eutectic mixture of cyanoparaphenylenes known as E7. Two series of blends are prepared under different conditions. The first series is obtained by the polymerization induced phase separation (PIPS) process under UV‐curing starting from a monomeric mixture, while the second series is prepared by a combination of the solvent induced phase separation and the thermally induced phase separation process starting from a mixture containing a commercial polymer with known molecular weight. Using gel permeation chromatography, it is found that the polymer molecular weight of the UV‐cured systems decreases with the concentration of LC in the precursor mixture. The experimentally obtained phase diagrams of these two series of systems show a miscibility shift at the composition where the molar mass of the polymer in the PIPS/UV blend exceeds that of the commercial polymer. Data are rationalized in terms of the Flory‐Huggins theory of isotropic mixing and the Maier‐Saupe theory of nematic order. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 18–27, 2007
Thickness dependence of free‐standing thin films
Authors: Guérin Gérald , Prud'homme Robert E.
Published: November 2006

Below a critical thickness, of about 60 nm, the glass transition temperature of polystyrene (PS) films decreases with film thickness, as demonstrated using free‐standing films. A geometrical model is developed here describing this phenomenon in the case of ideal (Gaussian) chains. This model, which can be considered as an application of the free volume model, assumes that the decrease of the glass transition temperature from thick to ultrathin films is due to the modification of the interpenetration between neighboring chains. The theoretical curve deduced from the model is in excellent agreement with the PS experimental results, without using any adjustable parameters. From these results, it can be concluded that new chain motions, usually buried in bulk samples, are expressed by the presence of the surface. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 10–17, 2007
Distress overlaps with anxiety and depression in patients with head and neck cancer
Authors: Pandey Manoj , Devi Nandkumar , Thomas Bejoy C. , Vinod Kumar S. , Krishnan Rita , Ramdas K.
Published: November 2006

Psychological problems in cancer patients often go unrecognized until they are specifically sought. This is more in patients with depression as they are reluctant to complain about their symptoms. The present study was carried out to evaluate the relation of distress with anxiety and depression in 123 patients with head and neck cancers using Distress Inventory for Cancer version 2 (DIC2) and the Hospital Anxiety and Depression scale (HADS). The mean DIC 2 scores were 24.6 while that of subscales ranged from 2.6 to 11.0. Fifteen patients were found to have clinical caseness for anxiety while 12 (10%) were caseness for depression. Total distress, emotional and social distress subscales were found to have positive correlation with anxiety and depression suggesting a possible overlap of two constructs. In multivariate analysis only belief in god was found to significantly affect the distress. Results of present study suggest significant psychological morbidity in head neck cancer patients undergoing curative treatment. This is the first study reporting on the psychometric properties of distress inventory on cancer version 2 since its validation, the results suggest a possible overlap of two constructs similar to that seen with other tools on distress and this may have major implications for clinical practice. Copyright © 2006 John Wiley & Sons, Ltd.
Description of atomic burials in compact globular proteins by Fermi‐Dirac probability distributions
Authors: Gomes Antonio L. C. , de Rezende Júlia R. , de Araújo Antônio F. Pereira , Shakhnovich Eugene I.
Published: November 2006

We perform a statistical analysis of atomic distributions as a function of the distance R from the molecular geometrical center in a nonredundant set of compact globular proteins. The number of atoms increases quadratically for small R, indicating a constant average density inside the core, reaches a maximum at a size‐dependent distance Rmax, and falls rapidly for larger R. The empirical curves turn out to be consistent with the volume increase of spherical concentric solid shells and a Fermi‐Dirac distribution in which the distance R plays the role of an effective atomic energy ϵ(R) = R. The effective chemical potential μ governing the distribution increases with the number of residues, reflecting the size of the protein globule, while the temperature parameter β decreases. Interestingly, βμ is not as strongly dependent on protein size and appears to be tuned to maintain approximately half of the atoms in the high density interior and the other half in the exterior region of rapidly decreasing density. A normalized size‐independent distribution was obtained for the atomic probability as a function of the reduced distance, r = R/Rg, where Rg is the radius of gyration. The global normalized Fermi distribution, F(r), can be reasonably decomposed in Fermi‐like subdistributions for different atomic types τ, Fτ(r), with ΣτFτ(r) = F(r), which depend on two additional parameters μτ and hτ. The chemical potential μτ affects a scaling prefactor and depends on the overall frequency of the corresponding atomic type, while the maximum position of the subdistribution is determined by hτ, which appears in a type‐dependent atomic effective energy, ετ(r) = hτr, and is strongly correlated to available hydrophobicity scales. Better adjustments are obtained when the effective energy is not assumed to be necessarily linear, or ετ*(r) = hτ*rα,, in which case a correlation with hydrophobicity scales is found for the product ατhτ*. These results indicate that compact globular proteins are consistent with a thermodynamic system governed by hydrophobic‐like energy functions, with reduced distances from the geometrical center, reflecting atomic burials, and provide a conceptual framework for the eventual prediction from sequence of a few parameters from which whole atomic probability distributions and potentials of mean force can be reconstructed. Proteins 2007. © 2006 Wiley‐Liss, Inc.
A flame speed correlationfor unconfined gaseous explosions
Authors: Dorofeev Sergey B.
Published: November 2006

An approximate method for description of flame acceleration in congested areas filled with combustible gases is presented. The method takes into account both the flame folding arising from interactions with obstacles of the flow produced by the flame and the increase of the burning rate resulting from turbulence generated in the flow ahead of the flame. A simple analytical expression for the flame speed is suggested. Coefficients in this correlation are determined by fitting the model predictions with a set of experimental data. This correlation is then used to evaluate the maximum flame speed that may be developed in vapor cloud explosions as a function of scale and obstacle density. As an example of applications, the flame speeds are evaluated for four typical fuels: methane, propane, ethylene, and hydrogen, and for three different levels of congestion. Both ideal stoichiometric mixtures of the four fuels with air and clouds with nonuniform concentration distributions are considered. The method is shown to take appropriate account of mixture properties. In particular, the well‐known difference in combustion behavior of methane, propane, ethylene, and hydrogen was well captured by the method. On the basis of the maximum flame speeds, the severity of the blast effect from unconfined gaseous explosions is evaluated. The results are compared with other methods for evaluation of the blast effect from unconfined vapor cloud explosions. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2007
Synthesis of Aβ[1‐42] and its derivatives with improved efficiency
Authors: Zarándi Márta , Soós Katalin , Fülöp Lívia , Bozsó Zsolt , Datki Zsolt , Tóth Gábor K. , Penke Botond
Published: November 2006

It has been proved that the principal component of senile plaques is aggregates of β‐amyloid peptide (Aβ) in cases of one of the most common forms of age‐related neurodegenerative disorders, Alzheimer's disease (AD). Although the synthetic methods for the synthesis of Aβ peptides have been developed since their first syntheses, Aβ[1‐42] is still problematic to prepare. The highly hydrophobic composition of Aβ[1‐42] results in aggregation between resin‐bound peptide chains or intrachain aggregation which leads to a decrease in the rates of deprotection and repetitive incomplete coupling reactions during 9‐flurenylmethoxycarbonyl (Fmoc) synthesis. In order to avoid aggregation and/or disrupt internal aggregation during stepwise Fmoc solid phase synthesis and to improve the quality of crude products, several attempts have been made. Since highly pure Aβ peptides in large quantities are used in biological experiments, we wanted to develop a method for a rational synthesis of human Aβ[1‐42] with high purity and adequate yield.

This paper reports a convenient methodology with a novel solvent system for the synthesis of Aβ[1‐42], its N‐terminally truncated derivatives Aβ[4‐42] and Aβ[5‐42], and Aβ[1‐42] labeled with 7‐amino‐4‐methyl‐3‐coumarinylacetic acid (AMCA) at the N‐terminus using Fmoc strategy. The use of 10% anisole in Dimethylformamide/Dichloromethane (DMF/DCM) can substantially improve the purity and yield of crude Aβ[1‐42] and has been shown to be an optimal coupling condition for the synthesis of Aβ[1‐42]. Anisole is a cheap and simple aid in the synthesis of ‘difficult sequences’ where other solvents are less successful in the prevention of aggregation during the synthesis. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Diversity of the O‐superfamily conotoxins from Conus miles
Authors: Luo Sulan , Zhangsun Dongting , Feng Jiancheng , Wu Yong , Zhu Xiaopeng , Hu Yuanyan
Published: November 2006

Conopeptides display prominent features of hypervariability and high selectivity of large gene families that mediate interactions between organisms. Remarkable sequence diversity of O‐superfamily conotoxins was found in a worm‐hunting cone snail Conus miles. Five novel cDNA sequences encoding O‐superfamily precursor peptides were identified in C. miles native to Hainan by RT‐PCR and 3′‐RACE. They share the common cysteine pattern of the O‐superfamily conotoxin (CCCCCC, with three disulfide bridges). The predicted peptides consist of 27–33 amino acids. We then performed a phylogenetic analysis of the new and published homologue sequences from C. miles and the other Conus species. Sequence divergence (%) and residue substitutions to view evolutionary relationships of the precursors' signal, propeptide, and mature toxin regions were analyzed. Percentage divergence of the amino acid sequences of the prepro region exhibited high conservation, whereas the sequences of the mature peptides ranged from almost identical with to highly divergent from inter‐ and intra‐species. Despite the O‐superfamily being a large and diverse group of peptides, widely distributed in the venom ducts of all major feeding types of Conus and discovered in several Conus species, it was for the first time that the newly found five O‐superfamily peptides in this research came from the vermivorous C. miles. So far, conotoxins of the O‐superfamily whose properties have been characterized are from piscivorous and molluscivorous Conus species, and their amino acid sequences and mode of action have been discussed in detail. The elucidated cDNAs of the five toxins are new and of importance and should attract the interest of researchers in the field, which would pave the way for a better understanding of the relationship of their structure and function. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Pro‐apoptotic bax‐α1 synthesis and evidence for β‐sheet to α‐helix conformational change as triggered by negatively charged lipid membranes
Authors: Sani Marc‐Antoine , Loudet Cécile , Gröbner Gerhard , Dufourc Erick J.
Published: November 2006

Solid phase synthesis of Bax‐α1, the 25 amino acids domain (14TSSEQIMKTGALLLQGFIQDRAGRM38) of the pro‐apoptotic Bax protein has been accomplished using Fmoc chemistry. A new fast and harmless protocol is described for complete TFA removal from the purified peptide powder leading to a final purity greater than 98% as controlled by 19F‐NMR, UV and MALDI‐TOF mass spectrometry. Secondary structure was determined in various solution and membrane media using UV Circular Dichroism. In water solution, Bax‐α1 is present as a mixture of β‐sheet and unstructured (random coil) conformations. A marked change from β‐sheet to α‐helix secondary structures is observed upon interaction with negatively charged phospholipids vesicles whereas neutral lipid membranes have no significant effect on the aqueous peptide conformation. Results are discussed in terms of Bax binding to mitochondrial membranes. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
The fractal nature of elastic aftereffect in metallic materials
Authors: Novikov V. , Usov V. , Shkatul'ak N.
Published: November 2006

Experimental investigations of the phenomenon of the elastic aftereffect of a number of metallic materials have been carried out. It was found that the time‐dependent deformation may be described by a power function of time with fractional index. A mathematical model that describes the elastic aftereffect on a basis of fractal ideas about the process of deformation is constructed. A concept of a fractal set of relaxation periods is offered as an explanation of the elastic stability of the crystals, – or of their instability, i.e., emergence of residual deformation under the influence of external stress on the crystal system. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thickness dependence of susceptibility and phase transition temperature in ferroelectric thin films
Authors: Lo V. C. , Li K. T.
Published: November 2006

The thickness dependence of the susceptibility and paraelectric–ferroelectric phase transition temperature in ferroelectric thin films has been numerically simulated using Landau–Khalatnikov theory. This dependence is attributed to the presence of a surface layer near the electrode/film interface. In the presence of interfacial strain, the surface layer exhibits different ferroelectric properties compared with those inside the film. The thickness dependence of coercive field and remanent polarization has been successfully simulated before by considering the presence of this surface layer [V. C. Lo, J. Appl. Phys. 94, 3353 (2003)]. Based on the same model, the experimental trends in the thickness dependence of susceptibility and phase transition temperature can be reproduced. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transfer‐matrix approach to the problem of electrical conduction through a series of absorbers
Authors: Walczak Kamil
Published: November 2006

Here we study incoherent transport through molecular wire treated as a linear chain of absorbers, where the phase‐breaking processes are modeled by the use of imaginary point‐like potentials. The calculations are performed within a transfer matrix method of the scattering theory. An analytic expression for the transmission of a finite chain is obtained, while the electrical current is then computed with the help of the Tsu–Esaki formula. In particular, it is shown that the maximal current dependence on the wire length is exponential. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parthenium hysterophorus induced changes in neurotransmitter levels in mouse brain
Authors: Verma Sabita , Shrivastava Renu , Prasad P. K. , Shrivastava Vinoy K.
Published: November 2006

Parthenium hysterophorus (10 mg/0.1 ml/kg body weight) was administered daily to 20 adult male mice and levels of 5‐hydroxytryptamine, noradrenaline and dopamine in total brain were quantified on days 31 and 61 after administration. All neurotransmitter levels were decreased significantly, with the effects more prominent in the later part of the experiment. The results suggest that Parthenium hysterophorus interferes in the functioning of the hypothalamo–hypophyseal axis by impairing the biogenic amine levels which may in turn affect the physiology of the peripheral endocrine glands. Copyright © 2006 John Wiley & Sons, Ltd.
The water extract of Omija protects H9c2 cardiomyoblast cells from hydrogen peroxide through prevention of mitochondrial dysfunction and activation of caspases pathway
Authors: Park Channy , So Hong‐Seob , Shin Sun‐Ho , Choi Jin‐Young , Lee In , Kim Jin‐Kyung , Chung Sang‐Young , Park Raekil
Published: November 2006

The water extract of Omija (Omija) has been used traditionally in the treatment of ischemic damage of the heart and brain tissues. However, little is known about the mechanism by which it rescues myocardial cells from oxidative stress. This study was designed to investigate the protective mechanisms of Omija on H2O2‐induced cytotoxicity in H9c2 cardiomyoblast cells. Treatment with H2O2 resulted in the death of H9c2 cells, characterized by apparent apoptotic features, including fragmentation of the nucleus and an increase in the sub‐G0/G1 fraction of the cell cycle. However, Omija markedly suppressed the apoptotic characteristics of H9c2 cells induced by H2O2. In addition, Omija suppressed the features of mitochondrial dysfunction, including changes in the mitochondrial membrane potential and cytosolic release of cytochrome c in H2O2‐treated cells. Treatment with Omija further inhibited the catalytic activation of caspase‐9 and caspase‐3 and induction of Fas by H2O2. Taken together, these data indicate that the water extract of Omija protects H9c2 cardiomyoblast cells from oxidative stress of H2O2 through inhibition of mitochondrial dysfunction and activation of intrinsic caspase cascades, including caspase‐3 and caspase‐9. Copyright © 2006 John Wiley & Sons, Ltd.
A new approach to determine method detection limits for compound‐specific isotope analysis of volatile organic compounds
Authors: Jochmann Maik A. , Blessing Michaela , Haderlein Stefan B. , Schmidt Torsten C.
Published: November 2006

Compound‐specific isotope analysis (CSIA) has been established as a useful tool in the field of environmental science, in particular in the assessment of contaminated sites. What limits the use of gas chromatography/isotope ratio mass spectrometry (GC/IRMS) is the low sensitivity of the method compared with GC/MS analysis; however, the development of suitable extraction and enrichment techniques for important groundwater contaminants will extend the fields of application for GC/IRMS. So far, purge and trap (P&T) is the most effective, known preconcentration technique for on‐line CSIA with the lowest reported method detection limits (MDLs in the low µg/L range). With the goal of improving the sensitivity of a fully automated GC/IRMS analysis method, a commercially available P&T system was modified. The method was evaluated for ten monoaromatic compounds (benzene, toluene, para‐xylene, ethylbenzene, propylbenzene, isopropylbenzene, 1,2,3‐trimethylbenzene, 1,2,4‐trimethylbenzene, 1,3,5‐trimethylbenzene, fluorobenzene) and ten halogenated volatile organic compounds (VOCs) (dichloromethane, cis‐1,2‐dichloroethene, trans‐1,2‐dichloroethene, carbon tetrachloride, chloroform, 1,2‐dichloroethane, trichloroethene, tetrachlorethene, 1,2‐dibromoethane, bromoform). The influence of method parameters, including purge gas flow rates and purge times, on δ13C values of target compounds was evaluated. The P&T method showed good reproducibility, high linearity and small isotopic fractionation. MDLs were determined by consecutive calculation of the δ13C mean values. The last concentration for which the δ13C value was within this iterative interval and for which the standard deviation was lower than ±0.5‰ for triplicate measurements was defined as the MDL. MDLs for monoaromatic compounds between 0.07 and 0.35 µg/L are the lowest values reported so far for continuous‐flow isotope ratio measurements using an automated system. MDLs for halogenated hydrocarbons were between 0.76 and 27 µg/L. The environmental applicability of the P&T‐GC/IRMS method in the low‐µg/L range was demonstrated in a case study on groundwater samples from a former military air field contaminated with VOCs. Copyright © 2006 John Wiley & Sons, Ltd.
The contribution of six developing countries' industry to sustainable development
Authors: Luken Ralph A. , Hesp Paul
Published: November 2006

The extent to which recent changes in industrial development and environmental policies in six countries (Chile, China, Pakistan, Tunisia, Turkey and Zimbabwe) have more closely aligned the objectives of industrial development with those of sustainable development are assessed in this article. The six countries did not make great advances in policy integration in support of sustainable development in the 1990s in terms of policy coordination, cooperation or coherence, but some did better than others. The countries showed considerable variation in the effectiveness with which they implemented their industrial development and environmental policy regimes. Lastly, the impact of industry on sustainable development also varied considerably, depending on which economic, social and environmental parameters were used to assess their contribution. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Altering without change
Authors: Zimmer J. A.
Published: November 2006

A method is presented for showing that a revised program is similar to its original. The method allows formal expression of intuitive concepts about why the revision has not changed algorithmic features. It breaks the original problem of comparing programs down to subproblems requiring that program fragments be described and allows the concept of program similarity to be adjusted to the particular situation.
SOFTM: A software maintenance expert system in Prolog
Authors: Pau L. F. , Kristinsson J. B.
Published: November 2006

This paper describes a software maintenance knowledge‐based system called SOFTM, which serves the three following purposes: (1) assisting a software programmer or analyst in application code maintenance tasks and reverse engineering, (2) generating and updating automatically software correction documentation, (3) helping the end user register, and possibly interpret, observed errors on the successive application code versions. The knowledge‐based system SOFTM is written in Prolog II, and is largely applicable to application codes written in different programming languages, provided that a description of the application code can be retrieved. SOFTM does not address any of the syntactic, input‐output, or procedural errors normally detected by the syntactic analyser, the compiler, or the operating system environment, although some of these extensions are possible. SOFTM is relying on a unique augmented transition network‐based code description, on diagnostic inference procedures based on context‐based pattern classification, on maintenance log report generators, and on interfacing capabilities of Prolog II to a variety of other languages. It also incorporates features whereby application code specific facts can be retrieved by the operating system (VMS) using a command procedure and asserted directly in the SOFTM knowledge bases. An application case is given for FORTRAN code.
On the benefits and difficulties of a maintainability via metrics methodology
Authors: Lewis John A. , Henry Sallie M.
Published: November 2006

A metrics methodology can dramatically reduce the problems associated with software maintenance. However, several issues must be addressed in order to develop and use these techniques successfully. This paper defines a metrics methodology which is designed to deliberately integrate maintainability into software as it is being developed. The benefits of using this approach are discussed. Then several issues which complicate the development and use of the methodology are examined. Previous maintenance studies which incorporate the methodology into two different commercial environments are used to demonstrate the difficulties in implementation and contrast the differences in approach.
Cognitive approach to systems engineering and re‐engineering: Integrating new designs with old systems
Authors: Scandura Joseph M.
Published: November 2006

Most MIS expense goes into the maintenance of existing software. Estimates vary from 50% to 60% at the low end up to 90%, even 95%, depending on responsibilities and the type of software. Coming up with better ways to maintain (i.e. understand, modify and update) existing software is unquestionably the most important challenge facing the software industry today.

Saddled with obsolete but essential software, a growing number of organizations are faced with a series of unpalatable choices. One option is to simply continue with the same old software, patching it where possible to meet the most pressing needs. This approach has a number of limitations not the least of which are lost opportunity and reduced competitiveness. Moreover, owing to unforeseen and increasing interactions, time per unit of change (especially structural change) tends to increase exponentially throughout the maintenance life cycle.

Eventually, old systems must either undergo a major overhaul or be replaced with new ones. Properly done, and implemented, either approach can add a measure of efficiency previously impossible—and cost recovery can often be accomplished over a reasonable period of time. The initial costs involved in such renewal, on the other hand, are often prohibitive.

Faced with this dilemma, what are decision makers to do? In this paper, I propose a new approach to system maintenance which can both dramatically improve systems and minimize renewal costs. In turn, I describe a typical maintenance scenario, and consider the use of CASE restructuring tools. Then I show how the human or cognitive factor impinges on the maintenance issue, and how this implies the need for abstraction. Next, we note limitations of standard “bubble chart” and other notational schemes and introduce the FLOWform representation as a means of overcoming these limitations.

Finally, with this background, I describe the Cognitive Approach to Systems Engineering and Re‐Engineering (CogApp). In this context, I summarize capabilities of the PRODOC re/NuSys WorkbenchTM which has been used to implement the CogApp. I close with a short case history describing application of this approach, and the results obtained therefrom.
Software maintenance management: Changes in the last decade
Authors: Nosek John T. , Palvia Prashant
Published: November 2006

Compared to a decade ago, when the first comprehensive study was done in software maintenance, many changes have occurred in the practice of system development. Longitudinal data were obtained by using the same survey instrument, updated to reflect current practices, and sampling the same population. Comparing the current with 1977 results has helped to identify the persistent problems and issues as well as the emerging problems and issues.

One of the important, but somewhat disturbing, conclusions is that maintenance problems are pretty much the same as during the 1970s (except for minor changes), despite advances made in structured methodologies and techniques. In terms of specific problems, personnel problems of maintenance programmers, i.e. turnover and availability, and programmer effectiveness problems, i.e. skills, motivation and productivity, have shown a rise, while problems associated with users' knowledge of computer systems have declined.
European special interest group in software maintenance
Authors: Bennett Keith H.
Published: November 2006

A new Special Interest Group in Software Maintenance has been formed in Europe. The idea was initially proposed by the European Commission, which is funding two maintenance projects through the ESPRIT II collaborative programme of Information Technology Research.

Membership is open to anyone (European or otherwise) interested in software maintenance. This short article summarizes the objectives and operation of the Special Interest Group.

The two ESPRIT software maintenance projects are called MACS and REDO. Between them, these projects bring together researchers and practitioners across the whole of Europe. The belief was (and is) that with this as a basis, there would be many people and organisations who are not yet directly involved, but who would wish to participate in a maintenance‐oriented organisation.
A specification‐based approach to maintenance
Authors: Lano K. , Haughton H.
Published: November 2006

In this paper we define a language, Z++, and a method based upon this language, to support the use of formal methods in software maintenance. Formal methods have been proposed several times as the solution to the growing problem of software maintenance, and we base our approach on the more successful of the attempts made to apply these methods.

Our approach is to use a conceptually simple framework, based on an object‐oriented extension to the specification language Z (Spivey, 1989), for dealing with requests for changes to software for which some formal documentation and record of development already exists.

The method is centered on the maintenance of the specifications and the development record, not upon source code or Structured Methodology documentation. It is proposed as a practical approach for software in the medium‐term future, allowing the mass of programming detail that makes the code maintenance problem so expensive to be ignored. Therefore changes and extensions to application systems can be made more rapidly. We describe the language and give details of the specification and refinement system, together with a description of the current state of the implementation of this system.
Intelligent search and acquisition of business knowledge from programs
Authors: Karakostas V.
Published: November 2006

This paper discusses the prototype system IRENE which employs concept acquisition techniques in order to retrieve business knowledge from COBOL programs. In contrast with the mainstream of reverse‐engineering techniques, IRENE relies on the availability of semantic (rather than syntactic knowledge), expressed as dependencies and derivations amongst the business entities represented in the program, derived by a process known as domain engineering.
Application of automatic decomposition schemes in proof maintenance for evolving programs
Authors: Gopal R. , Schach S. R.
Published: November 2006

The application of formal verification in software engineering is limited because programs continue to evolve during the maintenance phase, thus rendering the original verification obsolete. Program decomposition schemes can be used to identify the parts of the modified program that need verification. The original program verification can be reused and combined with the verification of the parts of the modified program. Automatic decomposition of programs into independent computational threads called projections can be performed by utilizing program‐dependence relations. These relations represent dependence information among the variables and statements of a program. The individual proofs of each projection can be combined to produce the verification of the entire program. After a modification, many of the original projections may still be present in the new program and they are not re‐verified. Only new projections need verification which is usually easier than re‐verifying the entire program.
Capturing design and maintenance decisions with MACS
Authors: Desclaux Christine
Published: November 2006

MACS1 is a research and development project of the European ESPRIT II programme, whose objective is the definition and implementation of a software maintenance assistance system. The basic premise of MACS is to do maintenance through understanding. MACS offers to view the application from several points of view in specific ‘worlds’. One of them is the ‘Reasoning World’, the central subject of the present paper; it captures by means of a simple formalism, the Problem‐Solution‐Decision formalism, the rationale underlying the design and maintenance process. MACS data integration is provided by a central base called the Interconnection World. Moreover, MACS proposes to guide the maintainer in applying a strategy, and in fully exploiting the possibilities of the MACS tools themselves by means of AI techniques and knowledge‐based support; throughout, however, the maintainer remains the master of maintenance actions.
Total quality management for maintenance process improvement
Authors: Schatzberg Doreen R.
Published: November 2006

The acquisition of a new system's operations and maintenance responsibility offered an opportunity to apply different methods in the University of Wisconsin—Extension maintenance organization. Total Quality Management (TQM) methods were chosen because they support broader objectives deemed beneficial to maintenance operations. TQM methods focus on the customer, are implemented through teams, and use data to make decisions rather than relying on inferences or assumptions. The team analyses, assesses, and continually improves the process of maintenance to ensure the product meets customer needs and answers root causes of problems. This paper describes the team's planning, implementation, and validation efforts accomplished, and the findings from the pilot project.

In addition to this report on the pilot project, this paper includes several reasons why TQM methods may be particularly amenable to software maintenance functions. They are: (1) the inherent customer‐focus of maintenance activities; (2) the advantages of team work for gaining consensus on improvements, thereby potentially limiting re‐work; and (3) the data‐based, task‐sequenced, structured, analytic techniques used in TQM. Unresolved issues in applying TQM in maintenance organizations include the definition of customer versus user, the need to manage customer expectations, and the application for use in service organizations of techniques honed in manufacturing organizations. This paper is a first step in addressing some of these issues. It provides a preliminary model for applying TQM methods in maintenance organizations.
A semantics‐based method for revalidating modified programs
Authors: Chung In Sang , Kwon Yong Rae
Published: November 2006

Software revalidation through retesting during the maintenance phase is essential for establishing confidence in the reliability of the modified programs. In this paper, we present a testing criterion and techniques for revalidating modified programs as well as the conditions to determine the necessity for revalidation of the modified program. By comparing programs and identifying the textual and semantic changes between them, it is shown that the number of test cases to be rerun can be reduced compared to the current revalidation methods. Our method is applicable to programs with different control structures from the original program with a little effort by treating the test case reuse problem as a constraint satisfaction problem. In addition, application of an zero‐one integer programming model to select the minimal set of paths to be retested is explored.
A software maintenance management model based on queueing networks
Authors: Papapanagiotakis Giorgos , Breuer Peter
Published: November 2006

A model of the software maintenance process within a medium‐sized organization is described. We set out both the abstract model and its implementation as part of a management tool, the Intelligent Software Maintenance Management System (ISMMS) prototype.

The ISMMS provides a simulation environment for two sorts of management activities. In interactive mode, the characteristics of a particular set of maintenance tasks can be fed into the simulation, and decisions on the allocation of real personnel, tools and resources tested. In automatic mode, a spectrum of tasks is generated and different automatic allocation strategies are statistically evaluated against these. In both modes, the simulation draws on a database which is customized to accurately reflect the particular resources and characteristics of the organization using the model.

The detailed abstract maintenance process underlying the prototype is described in terms of queues arranged in a topological network. This provides a clean conceptual model which has been successfully implemented using a three‐layer software architecture in the ISMMS prototype; the abstract queueing model is implemented as a synchronized predicate‐net which in turn is implemented in Prolog, and we describe the implementation here, as well as its behaviour from the user's point of view.
A decision model to choose between software maintenance and software redevelopment
Authors: Sakthivel Sachidanandam
Published: November 2006

Studies show that the maintenance stage of the software life cycle consumes a large proportion of software development resources. They also show that the maintenance cost of a software product increases with age and that it costs less to maintain the redeveloped software product. Thus, it may be worthwhile to redevelop software to reduce the maintenance costs but the redevelopment costs may prohibit this. This paper discusses the nature and behaviour of software maintenance costs and software development costs. In order to minimize the sum of maintenance and development costs for a software product, it recommends and illustrates the use of replacement theory. The replacement model suggested in this paper will be useful for choosing between redeveloping the software and maintaining the existing software. This paper provides a worked example consistent with replacement theory. Since capital is in short supply, replacement projects have to vie with new software and maintenance projects for funding. This paper also describes building a software project portfolio of new software development, software maintenance, and software redevelopment projects.
A road map for migrating legacy systems to client/server
Authors: Mittra Sitansu S.
Published: November 2006

Applications developed during the 1970s in a centralized computing environment have become legacy applications in today's decentralized world, increasingly expensive to maintain. One way to improve their use and maintainability in the present environment is to migrate them to the client/server (C/S) world while salvaging as much as possible during that process. This paper, a road map for that migration, examines how legacy applications differ from C/S applications and prescribes a course of action to remove the non‐C/S characteristics from legacy applications and to replace them with C/S characteristics. In this process we need to address a variety of technical issues involving databases, network and configuration management as well as organizational issues such as data and process models used by different parts of the organization, and user/customer training in the new C/S paradigm. The goal of the migration process is to implement an application environment consisting of heterogeneous, distributed, multi‐DBMS applications dynamically linking legacy systems and relational or object‐oriented databases in real time, without the coding costs or challenges of twophase commit. Middleware tools are used widely to re‐engineer legacy applications to fit a C/S environment. A variety of CASE tools are available to support modifying such functions as query and reporting, and cross‐platform development. The paper discusses these issues and concludes with a brief description of resources and tools that can help in travelling the migration road.
Context‐dependent flow‐sensitive interprocedural dataflow analysis
Authors: Johmann Kurt R. , Liu Sying‐Syang , Yau Stephen S.
Published: November 2006

Interprocedural dataflow analysis is useful in compiler optimization, automatic vectorization and parallelization, dataflow anomaly detection, and software maintenance applications such as program revalidation, and software tools that make a program more understandable by showing data dependencies. These applications require the solution of dataflow problems such as reaching definitions, live variables, available expressions, and definition‐use chains. When solving these problems interprocedurally, the context of each call must be taken into account. In this paper, a method to solve this kind of dataflow problem is presented. This method consists of special dataflow equations that are solved for a program flowgraph. In deference to calling context, separate sets, called entry and body sets, are maintained at each node in the flowgraph. The entry set contains calling‐context effects that enter a procedure. The body set contains effects that result from statements in the procedure. By isolating calling‐context effects in the entry set, a call's nonkilled calling context is preserved by means of a simple intersection operation done at the return node for that call. The main advantages of this method are its precision and low complexity, and the fact that the presence of recursion does not affect the accuracy of the result.
An examination of software maintenance practices in a U.S. government organization
Authors: Brown Alan W. , Christie Alan M. , Dart Susan A.
Published: November 2006

In an effort to find out more about the effectiveness of the tools, procedures, and techniques that project personnel use in their work, the Computer‐Aided Software Engineering (CASE) Environments project at the Software Engineering Institute interviewed personnel in eight software maintenance projects within a U.S. Government organization. These interviews highlighted problems that we believe are typical of many software maintenance organizations and are the subject of this paper. While the interviews discovered a need for maintenance tools to support such areas as reverse‐engineering and regression testing, these problems often had their roots in deeper issues. Such issues were a lack of design for maintenance, ineffective communication and low status of maintenance work. This paper addresses these deeper issues and suggests some approaches for their resolution.