bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MISFORTUNE OF THE HAPPY
Authors: Ferreira M. Jamie
Published: August 2006

Levinas himself raises the question: “why would I feel responsible in the presence of the Face” since “we are separate ontological beings?” This questions the character of our response to the other—both in terms of agency and motivation. While the general reception of Levinas's thought has focused on his description of us as “hostage”—that is, on the moment of assignation (or assignment) by the other—I suggest that Levinas himself also, though not as directly, addresses (as he needs to) the correlative moment, the moment of response. My essay reconstructs Levinas's implicit understanding of the character of our initiative in the light of his concept of Desire. I explore the different dimensions of Desire as appetite and generosity, and I argue that the “transition to moral consciousness” that Levinas wants to “justify” is one from complacent happiness to “non‐complacent happiness” and can be illuminated by the notion of “passion seeking its downfall.”
From Beveridge to Turner: Demography, Distribution and the Future of Pensions in the UK
Authors: Hills John
Published: August 2006

The paper outlines the recommendations of the UK Pensions Commission, and the data and analysis on which they were based, including projections of demographic change, trends in private pension saving and evolution of the State pension system. The Commission concluded that, without reform, structural problems with UK pensions would lead to increasingly inadequate and inequitable provision by 2020–2025. It recommended reforms which would lead to a more generous, more universal and less means-tested State system than would otherwise evolve, and the establishment of a low cost national pension savings scheme, into which employees without good employer provision would automatically be enrolled. The proposals, which have now largely been adopted by the UK Government, imply eventual increases both in state spending on pensions as a share of national income and in State pension age, but accompanied by measures to facilitate later and more flexible retirement.
Promoting Declines in the Prevalence of Late‐Life Disability: Comparisons of Three Potentially High‐Impact Interventions
Authors: FREEDMAN VICKI A. , HODGSON NANCY , LYNN JOANNE , SPILLMAN BRENDA C. , WAIDMANN TIMOTHY , WILKINSON ANNE M. , WOLF DOUGLAS A.
Published: August 2006

Although the prevalence of late‐life disability has been declining, how best to promote further reductions remains unclear. This article develops and then demonstrates an approach for comparing the effects of interventions on the prevalence of late‐life disability. We review evidence for three potentially high‐impact strategies: physical activity, depression screening and treatment, and fall prevention. Because of the large population at risk for falling, the demonstrated efficacy of multi‐component interventions in preventing falls, and the strong links between falls and disability, we conclude that, in the short run, multi‐component fall‐prevention efforts would likely have a higher impact than either physical activity or depression screening and treatment. However, longer‐term comparisons cannot be made based on the current literature and may differ from short‐run conclusions, since increases in longevity may temper the influences of these interventions on prevalence. Additional research is needed to evaluate longer‐term outcomes of interventions, including effects on length and quality of life.
A Tale of Two Counties: Expanding Health Insurance Coverage for Children in California
Authors: HOWELL EMBRY M. , HUGHES DANA
Published: August 2006

During difficult economic times, many California counties have expanded health insurance coverage for low‐income children. These Children's Health Initiatives (CHIs) enroll children in public programs and provide new health insurance, Healthy Kids, for those ineligible for existing programs. This article describes the policy issues in implementing the Santa Clara and San Mateo County CHIs, as well as the children's enrollment levels and utilization of services. These CHIs are among the first of the thirty California counties planning or implementing such initiatives. Their success depends on leadership from county agencies that have not traditionally worked closely together, as well as the development of a diverse public and private funding base. This effort to provide universal coverage for all children is important to national policymakers desiring similar goals.
The Effect of Substance Abuse Treatment on Medicaid Expenditures among General Assistance Welfare Clients in Washington State
Authors: WICKIZER THOMAS M. , KRUPSKI ANTOINETTE , STARK KENNETH D. , MANCUSO DAVID , CAMPBELL KEVIN
Published: August 2006

Little is currently known about the effect of substance abuse treatment on Medicaid expenses and other health care costs for welfare clients. This study examined the association between substance abuse treatment and reductions in medical care expenditures (primarily Medicaid expenses) for General Assistance (GA) welfare clients in Washington State. The treatment group included 3,235 GA clients who received treatment during 2000 or 2001. The comparison group included 4,863 GA clients who needed substance abuse treatment but did not receive it. Substance abuse treatment was associated with a reduction (p < .01) in medical expenses of approximately $2,500 annually. This estimated savings equaled the cost of treatment and represented approximately 35 percent of the annual Medicaid expenses incurred by GA clients with substance abuse problems.
Dual Approaches to the Analysis of Risk Aversion
Authors: CHAMBERS ROBERT G. , QUIGGIN JOHN
Published: August 2006

We present a dual formulation of choice under uncertainty based on a few simple assumptions about preferences. It is shown that the additive separability restriction on preferences, key to expected‐utility theory, can be dropped with little loss of analytic power for a broad class of choice problems. Dual risk premiums are characterized, and it is shown that placing various invariance restrictions on them leads naturally to generalizations of the concepts of CARA, CRRA, and LRT familiar from expected‐utility theory. Each of these generalizations conforms to a notion of homotheticity.
Cartilage, SOX9 and Notch signals in chondrogenesis
Authors: Hardingham Timothy E. , Oldershaw Rachel A. , Tew Simon R.
Published: August 2006

Cartilage repair is an ongoing medical challenge. Tissue engineered solutions to this problem rely on the availability of appropriately differentiated cells in sufficient numbers. This review discusses the potential of primary human articular chondrocytes and mesenchymal stem cells to fulfil this role. Chondrocytes have been transduced with a retrovirus containing the transcription factor SOX9, which permits a greatly improved response of the cells to three‐dimensional culture systems, growth factor stimulation and hypoxic culture conditions. Human mesenchymal stem cells have been differentiated into chondrocytes using well‐established methods, and the Notch signalling pathway has been studied in detail to establish its role during this process. Both approaches offer insights into these in vitro systems that are invaluable to understanding and designing future cartilage regeneration strategies.
How to build and rebuild a lens
Authors: Tsonis Panagiotis A.
Published: August 2006

Evolution has used many different strategies to build eyes and lenses. However, the genetic regulation involved seems to be quite conserved. Likewise, the regeneration of eye structures is remarkable, especially in salamanders. This review outlines the basic mechanisms of lens regeneration and its induction and the possibility of creating lenses by transdifferentiation of the pigment epithelial cells, by stem cells or by bioengineering.
Neuronal sensitivity to kainic acid is dependent on the Nrf2‐mediated actions of the antioxidant response element
Authors: Kraft Andrew D. , Lee Jong‐Min , Johnson Delinda A. , Kan Yuet Wai , Johnson Jeffrey A.
Published: August 2006

The transcription factor, nuclear factor E2 (erythroid‐derived 2)‐related factor 2 (Nrf2), is essential for the induction of a battery of phase II detoxification genes through the antioxidant response element (ARE) that lies in their promoter region. Genes driven by the ARE are up‐regulated in response to various stressors of the cellular environment. These genetic changes to the cellular reducing potential may reflect an intrinsic damage response to harmful toxicants. Analysis of transgenic reporter mice following kainate injection revealed selective ARE activation within the damaged hippocampus. Further, 2 × 2 microarray analyses comparing Nrf2 knockout versus wild‐type hippocampi unmasked gene changes associated with ion movement and myelination, in addition to alterations to detoxification‐related genes. Nrf2 knockout mice were more sensitive to kainate toxicity, as evidenced by elevated seizure severity, seizure duration, hippocampal neuron damage and mortality. Knockout mice injected with kainate displayed altered glial fibrillary acidic protein immunoreactivity and increased microglial infiltration. The wild‐type to knockout damage differential was not dependent on the peripheral metabolism of the excitotoxin, was well correlated with increased seizure susceptibility, and was therefore not necessarily the neuroprotective effects of Nrf2. These results combine to support a role for Nrf2 in the neural cell defense response of the adult brain.
Post‐ versus presynaptic plasticity in L‐DOPA‐induced dyskinesia
Authors: Cenci M. Angela , Lundblad Martin
Published: August 2006

L‐3,4‐dihydroxyphenylalanine (L‐DOPA) remains the most efficacious drug for the treatment of Parkinson's disease (PD), but causes adverse effects that limit its utility. L‐DOPA‐induced dyskinesia (abnormal involuntary movements) is a significant clinical problem that attracts growing scientific interest. Current notions attribute the development of dyskinesia to two main factors, viz. the loss of nigrostriatal dopamine (DA) projections and the maladaptive changes produced by L‐DOPA at sites postsynaptic to the nigrostriatal neuron. Basic research in the past 15 years has placed a lot of emphasis on the postsynaptic plasticity associated with dyskinesia, but recent experimental work shows that also some presynaptic factors, involving the regulation of L‐DOPA/DA release and metabolism in the brain, may show plasticity during treatment. This review summarizes significant studies of L‐DOPA‐induced dyskinesia in patients and animal models, and outlines directions for future experiments addressing mechanisms of presynaptic plasticity. These investigations may uncover clues to the varying susceptibility to L‐DOPA‐induced dyskinesia among PD patients, paving the way for tailor‐made treatments.
Rapid co‐release of interleukin 1β and caspase 1 in spinal cord inflammation
Authors: Clark Anna K. , D'Aquisto Fulvio , Gentry Clive , Marchand Fabien , McMahon Stephen B. , Malcangio Marzia
Published: August 2006

Mounting evidence supports the hypothesis that pro‐inflammatory cytokines secreted by astrocytes and microglia modulate nociceptive function in the injured CNS and following peripheral nerve damage. Here we examine the involvement of interleukin‐1β (IL‐1β) and microglia activation in nociceptive processing in rat models of spinal cord inflammation. Following application of lipopolysaccharide (LPS) to anex vivodorsal horn slice preparation, we observed rapid secretion of IL‐1β which was prevented by inhibition of glial cell metabolism and by inhibitors of either p38 mitogen‐activated protein kinase (MAPK) or caspase 1. LPS superfusion also induced rapid secretion of active caspase 1 and apoptosis‐associated speck‐like protein containing a caspase recruitment domain from the isolated dorsal horn. Extensive microglial cell activation in the dorsal horn, as determined by immunoreactivity for phosphorylated p38 MAPK, was found to correlate with the occurrence of IL‐1β secretion. In behavioural studies, intrathecal injection of LPS in the lumbar spinal cord produced mechanical hyperalgesia in the rat hind‐paws which was attenuated by concomitant injections of a p38 MAPK inhibitor, a caspase 1 inhibitor or the rat recombinant interleukin 1 receptor antagonist. These data suggest a critical role for the cytokine IL‐1β and caspase 1 rapidly released by activated microglia in enhancing nociceptive transmission in spinal cord inflammation.
Neuroprotectant FK506 inhibits glutamate‐induced apoptosis of astrocytes in vitro and in vivo
Authors: Szydlowska Kinga , Zawadzka Malgorzata , Kaminska Bozena
Published: August 2006

Neuron–astrocyte interactions are critical for signalling, energy metabolism, extracellular ion and glutamate homeostasis, volume regulation and neuroprotection in the CNS. Glutamate uptake by astrocytes may prevent excitotoxic glutamate elevation and determine neuronal survival. However, an excess of glutamate can cause the death of astrocytes. FK506, an inhibitor of calcineurin, and an immunosuppressive drug, is neuroprotective in animal models of neurologic diseases, including focal and global ischaemia. In the present work, we demonstrate that a single injection of FK506 60 min after a transient middle cerebral artery occlusion (MCAo) significantly decreases the number of terminal deoxynucleotidyl transferase nick‐end labelling (TUNEL)‐positive cells in the ischaemic cortex and striatum. Using 3‐D confocal microscopy we found that, 24 h after MCAo, many TUNEL‐positive cells in the ischaemic striatum and cortex are astrocytes. Furthermore, we demonstrate that exposure of cultured cortical astrocytes to 50–100 mM Glu for 24 h induces apoptotic alterations in nuclear morphology, DNA fragmentation, dissipation of mitochondrial transmembrane potential (ΔΨ) and caspase activation. FK506 (1 μM) efficiently inhibits Glu‐induced apoptosis of cultured astrocytes, DNA fragmentation and changes in mitochondrial ΔΨ. Our findings suggest that modulation of glutamate‐induced astrocyte death early after reperfusion may be a novel mechanism of FK506‐mediated neuroprotection in ischaemia.
Noncoding mitochondrial loci for corals
Authors: CONCEPCION GREGORY T. , MEDINA MONICA , TOONEN ROBERT J.
Published: August 2006

We developed five degenerate primer pairs for the amplification and sequencing of two noncoding regions found in the mitochondrial genome of corals. These primers amplify products ranging from 380 to 950 bp, and work in a wide variety of scleractinian taxa from both the Pacific and Caribbean. Based on our initial analysis of ∼300 sequences from 13 scleractinian taxa, both these noncoding regions appear to have equivalent levels of variability to the most variable of previously published coral mitochondrial loci, but work in a wider variety of taxa. We believe these primers will be of use to coral biologists studying questions above the level of species; as with other mithochondrial DNA markers in corals, these loci will likely provide little resolution for within‐species studies.
Identification of microsatellite loci in Collinsia verna (Veronicaceae)
Authors: DUNN JESSICA L. , DIERKES LINDSAY , PICÓ F. XAVIER , KALISZ SUSAN
Published: August 2006

We developed eight polymorphic microsatellite loci for Collinsia verna (Veronicaceae). In a sample of 18–35 individuals from a single population, we found two to 15 alleles per locus (mean 8.3). We also tested these loci for cross‐amplification in all 22 species in the tribe Collinseae. Overall, more than half the species in the tribe amplified one microsatellite while three species most closely related to C. verna (Collinsia violacea, Collinsia parviflora and Collinsia grandiflora) amplified multiple microsatellite loci. These microsatellite loci will be used in future studies of mating system in this tribe and other quantitative genetic and population genetic studies.
Polymorphic microsatellite markers isolated from partially enriched genomic library of Chitala chitala
Authors: PUNIA PEYUSH , GUPTA HARI SHANKAR , SINGH RAJEEV K , MOHINDRA VINDHYA , LAL KULDEEP K , RANJANA  , CHAUHAN V S , LAKRA W S
Published: August 2006

A total eight polymorphic microsatellite loci were obtained from genomic library of Indian feather back, Chitala chitala (order Osteoglossiformes, family Notopteridae) and the 46 samples were analysed to determine genetic variation. The mean number of alleles per locus ranged from 4.50 to 5.25, and expected heterozygosity ranged from 0.124 to 0.852. Deviation from Hardy–Weinberg equilibrium expectations (P < 0.002) was observed at loci Cch2, Cch9 (Bhaghirathi) and Cch9 (Brahmaputra). The identified microsatellite loci were found promising for population genetics studies of C. chitala and related species Notopterus notopterus (family Notopteridae).
Oxygen supplementation increases glucose tolerance during euglycaemic hyperinsulinaemic glucose clamp procedure in patients with severe COPD and chronic hypoxaemia
Authors: Jakobsson P. , Jorfeldt L.
Published: August 2006

Investigations in chronic obstructive pulmonary disease (COPD) patients have shown impaired glucose tolerance in hypoxic COPD patients, compared with COPD patients with normal arterial blood gases. In healthy subjects, hypoxaemia or stay at altitude, have been shown to alter glucose metabolism. At altitude the effect seems to be dependent on duration of stay. A short stay is associated with insulin resistance, a longer stay gives rise to increased glucose uptake. The euglycaemic hyperinsulinaemic glucose clamp technique is a method to study glucose tolerance and enables determinations of glucose clearance in peripheral tissues. We investigated six COPD patients [forced expiratory volume in 1 s 0·7 ± 0·2 l (mean ± SD)] with chronic hypoxaemia (PaO2 7·9 ± 0·6 kPa at rest, breathing air), with and without oxygen supplementation, using the glucose clamp technique. Net peripheral glucose uptake was 5·5 ± 1·2 and 7·1 ± 1·6 mg (kg*min)−1 (+29%) breathing air and supplemental oxygen, respectively (P = 0·03). The tissue sensitivity to insulin increased 32% (P = 0·03) with oxygen supplementation. The results indicate that normalization of oxygen saturation in COPD patients with chronic hypoxaemia may have an immediate effect on glucose tolerance and tissue sensitivity to insulin in these patients.
Influence of cardiac output level on oxygen exchange in chronic obstructive pulmonary disease patients
Authors: Manier Gérard , Pillet Odile , Castaing Yves
Published: August 2006

Study objectives:  In the course of chronic obstructive pulmonary disease (COPD), pulmonary gas exchange deteriorates as a result of ventilation/perfusion inequalities and hypoxaemia. The aim of the present study was to evaluate the influence of cardiac output (CO) level observed at rest in COPD patients on interaction between central and peripheral O2 exchange.

Methods:  One hundred and nine patients with advanced but stable COPD were analysed in a retrospective study by the multiple inert gas elimination technique. As a function of CO, simulations were conducted to evaluate the respective part of PvO2 and inequalities on the degree of hypoxaemia.

Measurements and results:  PaO2 was linked (i) to cardiac index (CI), (ii) to mean ratio of blood flow distribution and (iii) to PvO2, but PvO2 was not correlated with CO. By comparing two groups with CI above and below the mean value of the series respectively, a significant difference was identified in PaO2 (57 ± 9 mmHg in the high CI group versus 63 ± 10 mmHg in the low CI group, P<0·05) because of higher inequalities in the high CI group. Comparing two other groups with values of PvO2 above and below the mean value of the series respectively, a significant difference was identified in PaO2: (mean ± SD was 65 ± 8 in high PvO2 group versus 56 ± 9 mmHg, P<0·001) but with no difference in either CI or perfusion distribution. Analysis of the cumulated effects of PvO2 and CI values, indicated that high CI and low PvO2 gave rise to the lowest PaO2 (53 ± 8 mmHg), with the highest PaO2 (68 ± 8 mmHg) being found in the low CI and normal PvO2 group.

Conclusions:  We concluded that in COPD patients, PaO2 appeared to be maintained better when peripheral gas exchange coped with tissue demand without an increase in CO. Conversely, when the physiological increase in CO could not maintain adequate tissue gas exchange, PaO2 continued to fall due to the cumulative effects of increasing CO on inequalities and low PvO2.
Prognostic value of myocardial perfusion imaging in patients with known or suspected stable angina pectoris: Evaluation in a setting in which myocardial perfusion imaging did not influence the choice of treatment
Authors: Johansen Allan , Høilund‐Carlsen Poul F. , Vach Werner , Christensen Henrik W. , Møldrup Mette , Haghfelt Torben
Published: August 2006

Objective:  Previous investigations on the prognostic value of myocardial perfusion imaging (MPI) were performed under circumstances in which the test result was known to the patient's physician. We wanted to examine the prognostic value of MPI in patients with known or suspected stable angina in a setting in which MPI could not influence the diagnostic and therapeutic strategy.

Design:  A prospective series of 507 patients referred to coronary angiography for this condition were examined by MPI before angiography. Management was based on symptoms and angiographic findings, as the results of MPI were not communicated. Patients were followed for a mean of 45·3 ± 7·7 months.

Results:  During follow‐up, 20 patients (3·9%) suffered from myocardial infarction, 19 (3·8%) died and eight (1·6%) were revascularized >1 year after MPI resulting in a combined annual event rate of 2·5%. Patients with normal MPI had a low annual event rate of 1·6% (or 1·1% with regard to myocardial infarction or death only). In contrast, event rates in patients with reversible or mixed ischaemia were 4·0% per year. MPI added independent prognostic value to standard clinical data in a multivariate Cox model.

Conclusion:  We could confirm that in patients with known or suspected stable angina, MPI is a valuable risk stratifying tool.
Serial changes in the high‐frequency ECG during the first year following acute myocardial infarction
Authors: Trägårdh Elin , Pahlm Olle , Hedén Bo , Sörnmo Leif , Tägil Kristina , Wagner Galen S. , Pettersson Jonas
Published: August 2006

Background:  Previous studies have shown reduced high‐frequency QRS components (HF‐QRS) after acute myocardial infarction (MI). The purpose of this study was to investigate serial changes in HF‐QRS during the first year following acute MI.

Methods:  A total of 75 patients were included. Standard‐ and high‐frequency ECGs were recorded on five occasions during the year following the MI (a few days after the MI, after 6 weeks, and after 3, 6 and 12 months).

Results:  There was a statistically significant increase in HF‐QRS during the follow‐up year (P = 0·002). There were no significant differences in HF‐QRS when comparing either the infarct location or the presence or absence of reperfusive therapy. Large differences in HF‐QRS were observed, both intra‐individually and inter‐individually, during the year.

Conclusions:  There was a statistically significant increase in HF‐QRS during the year following acute MI.
Short‐term resistance training and the older adult: the effect of varied programmes for the enhancement of muscle strength and functional performance
Authors: Henwood Tim R. , Taaffe Dennis R.
Published: August 2006

Although it is well recognized that resistance training is an efficient strategy to enhance physical performance in older adults, less is known about the most effective type of resistive exercise or the role of functional training. This study compared the effectiveness of three varied short‐term (8 weeks) training protocols on muscle strength and functional performance in older men and women aged 65–84 years. Participants underwent twice‐weekly high‐velocity varied‐resistance training (HV), twice weekly slow to moderate‐velocity constant‐resistance training (CT), combined once weekly high‐velocity varied‐resistance and once weekly gymnasium‐based functional training (CB) or no training (CO). Dynamic muscle strength (1RM) of six muscle groups was assessed using isotonic equipment and functional performance by a battery of tests. Following 8 weeks of training, whole‐body muscle strength increased (P<0·001) by 22·0 ± 12·5% (mean ± SD), 21·7 ± 11·0% and 26·1 ±14·4% in HV, CT and CB, respectively, compared to CO (−1·8 ± 7·2%). In between group comparisons, only the HV group displayed greater chair rise ability (P =0·010) than the CO group, while differences among groups approached significance for the fast 6‐m walk and the stair climb test (P = 0·017 and 0·041 respectively). Within groups, the HV group significantly improved in stair‐climbing and chair rise ability (P≤0·001) while CB improved in the fast 6‐m walk (P = 0·003) and CT improved their static balance, as assessed by the functional reach test (P<0·001). This study indicates that twice weekly high‐velocity resistance training is superior to strength and combined functional and resistance training for improving some power‐orientated functional tasks. Although other functional performance improvements were modest among the training protocols, short‐term combined once weekly resistance and once weekly functional training in older adults was as effective in enhancing muscle strength as twice‐weekly resistance training. These results have important implications for older adults who are unable or unwilling to frequently attend exercise facilities.
Climate Change: Optimization of Response Strategies
Authors: Janssen M. , Rotmans J. , Vrieze K.
Published: August 2006

The development of climate change response strategies is expected to remain an important issue in the next few decades. The use of optimization techniques might serve as a helpful guide in this process. Although, in recent years, a number of studies have focused on optimization techniques, the optimization models do not fully employ the dynamics of climatic and economic systems. In this paper a heuristic is introduced that combines an integrated simulation model and an optimization technique (local search). This approach may be considered as a first step towards a more comprehensive and systematic analysis of climate change response strategies in a dynamic setting described by a simulation model. Results of a number of experiments in which the heuristic is applied to the integrated global assessment model TARGETS are discussed.
Operations Research Techniques in Manufacturing Planning and Control Systems
Authors: Olhager J. , Rapp B.
Published: August 2006

This paper investigates the possible uses for operations research (OR) models and techniques in manufacturing planning and control (MPC) systems. We discuss various MPC problems where OR can be applied and the potential inclusion of such models in computer‐aided MPC systems. It is found that even though the use of OR techniques in current standard MPC packages is rather restricted, there is a potential for utilizing more OR techniques in computer‐aided MPC systems, at least in theory. In practice, OR‐related techniques are more often developed as stand‐alone systems for decision support as a complement to the MPC system. In this paper, specific OR techniques are discussed for specific MPC problems in terms of applicability and the appropriate type of software solution; none at all, stand‐alone system or integrated part of the MPC system.
Multicriterion Analysis with Heterogeneous Attributes and Incomplete Information in a Non‐deterministic Context
Authors: Azondékon S.H. , Martel J‐M.
Published: August 2006

When dealing with non‐deterministic situations in a multiattribute context, once we accept the existence of different types of non‐determinism, we recognize implicitly that the nature of the various aspects (attributes) to be taken into account may be different from one attribute to another. Despite that, we have no knowledge about studies in MCDA concerning this situation of heterogeneous attributes relative to the type of non‐determinism. In this paper, considering the necessity of tackling such a problem, and taking into account recent studies on non‐deterministic situations in MCDA, we study two types of decision situation with heterogeneous attributes. The first one concerns situations with known importance variables, the second one concerns those with incomplete information about the importance variables.
Local Search Algorithms for the Maximal Planar Layout Problem
Authors: Hasan M. , Osman I.H.
Published: August 2006

The problem of laying out facilities is practically important in a modern manufacturing environment. This problem can be formulated as a weighted maximal planar graph in which vertices represent facilities and edge weights represent desirability measures between facilities. The objective is to find a planar graph that can be drawn on a plane without any edges intersecting with the highest sum of edge weights. Exact solution method can only solve small sized problems. In this paper, local search algorithms based on steepest ascent, hybrid simulated annealing and tabu search with a non‐monotonic cooling schedule, and tabu search with a hashing function are developed to obtain near‐optimal solutions. Different search strategies are investigated. All the developed algorithms are compared with existing construction methods and a branch and bound exact algorithm on a set of practical size problems. The proposed algorithms performed very well in terms of solution quality and computation time.
A Coordinate Descent Method for the Bi‐level O–D Matrix Adjustment Problem
Authors: Florian M. , Chen Y.
Published: August 2006

We present a Gauss–Seidel type algorithm for the problem of adjusting an O–D matrix by using observed flows in congested networks. The problem is formulated as a bi‐level optimization problem. Necessary conditions for some properties of the solution of the O–D matrix adjusting problem are derived and a coordinate descent method is developed. The algorithm takes full advantage of the network structure of the lower level problem and does not require many objective function evaluations. Computational results for some numerical examples are reported.
Motorway Network Control via Nonlinear Optimization
Authors: Messmer A. , Papageorgiou M.
Published: August 2006

The on‐line application of nonlinear optimization methods for control in motorway networks is presented. The considered control measure is route diversion by Variable Message Signs (VMS). The control task is formulated as a dynamic, nonlinear, discrete‐time optimal control problem with constrained control variables and is solved by a gradient‐based search. A modified algorithm for the heuristic search of optimal discrete (binary value) control sequences is presented. Feedback control is realized by solving the optimization problem for each control interval over a sufficiently long future time horizon (certainty equivalent open‐loop feedback control). As a prerequisite, a state‐space description of the network traffic dynamics is derived from a macroscopic model as used also in the simulation program METANET. Simulation results for route diversion on a hypothetical example network are given. The required computational effort is quantified and the control benefits are given in terms of network performance and the switching frequency of VMS.
An Information Handling Method for Corporate Planning Decision Support
Authors: Takai E. , Yamada Y.
Published: August 2006

This paper, by analyzing actual corporate planning procedures, proposes a method to classify management information used for decision making into several groups according to their characteristics. In order to select appropriate data as well as keep the data updated and readjusted to fit the continuously changing corporate planning environment, we emphasize the needs of information management by utilizing the classification proposed in this paper. An outline of the design concept of the data management system through the analysis of such characteristics on the actual data for planning in the oil refining industry is illustrated.
Supporting Developmental Decision Processes: the Evolution of an OR Approach
Authors: Friend J.
Published: August 2006

A case is developed for recognizing the distinctive contribution which OR scientists can make to the understanding and support of processes of developmental decision making, conceived as processes in which people work progressively (and often collaboratively) to address ever‐changing clusters of decisions which are richly connected and non‐recurrent. The argument is illustrated through reference to the evolution over the last three decades of the strategic choice approach to planning under uncertainty, as one example of an OR methodology that can be located within an emergent generic field of developmental decision science. It is argued that this perspective can complement that of systems theory in ways which are important not only for the future of OR, but also for the future development of human capacities to address daunting societal problems.
Modeling and Visualization for a Production Planning Decision Support System
Authors: Gazmuri P. , Arrate I.
Published: August 2006

This paper describes the process of decision support systems development for the optimization of the aggregate production planning problem for an important manufacturer of applicances in Chile. This work is part of a more general research effort, whose purpose is to build a generator of software applications for logistic problems in industry, based on optimization models. We take advantage of powerful tools and approaches for the modeling stage, and for building systems with user friendly interfaces and good data management capabilities. The production planning problem is formulated as a mixed integer programming model, which is solved using CPLEX. The system is currently being used by the company for their decision processes in manufacturing.
Electric Distribution Systems Planning with Fuzzy Loads
Authors: Matos M.A. , de Leão M.T. Ponce
Published: August 2006

Distribution systems planning heavily depends on the predicted future consumptions in the service area. When statistical data exist about past consumptions, probabilistic forecasting methods may be applied, and expected cost/benefit and risk analysis are used to decide between different solutions. In most cases, however, this strategy is not applicable, due mainly to the lack of significant data (new developing areas, rapidly changing situations) and uncertainty of economic and social factors. In the latter case, the use of fuzzy models is an interesting alternative, accommodating expert planner's qualitative judgments about future loads and allowing us to use ‘typical’ load diagrams in new areas. The paper discusses the main concepts of electric distribution system planning when loads are fuzzy modeled, and presents an illustrative application example.
On Prize‐collecting Tours and the Asymmetric Travelling Salesman Problem
Authors: Dell'Amico M. , Maffioli F. , Värbrand P.
Published: August 2006

We consider a variant of the Travelling Salesman Problem which is to determine a tour visiting each vertex in the graph at most at one time; if a vertex is left unrouted a given penalty has to be paid. The objective function is to find a balance between these penalties and the cost of the tour. We call this problem the Profitable Tour Problem(PTP). If, in addition, each vertex is associated with a prize and there is a knapsack constraint which guarantees that a sufficiently large prize is collected, we have the well‐known Prize‐collecting Travelling Salesman Problem (PCTSP). In this paper we summarize the main results presented in the literature, then we give lower bounds for the asymmetric version of PTP and PCTSP. Moreover, we show, through computational experiments, that large size instances of the asymmetric PTP can be solved exactly.
Combining Global Antithetic Forecasts
Authors: Ridley D.
Published: August 2006

This paper provides a summary of the theory for antithetic forecasting, and an empirical exposition. An original forecast is combined with another forecast, produced from a time series which is antithetic (negatively correlated) to the original time series. The forecasts are combined via a linear projection of the antithetic series on the original series, such that the component forecasts have negatively correlated errors. Large‐scale empirical tests and benchmark comparisons demonstrate the effectiveness of combining antithetic forecasts, even as these data depart from the strict theoretical lognormality requirement of antithetic forecasting. The method is illustrated in detail, using a real time series. Antithetic forecasting is the first combining method in which the gain increases with the forecast horizon.
Optimisation of a Simulated‐Annealing‐based Heuristic for Single Row Machine Layout Problem by Genetic Algorithm
Authors: Braglia M.
Published: August 2006

We discuss a procedure to determine the optimal set of parameters relevant to heuristics based on the Simulated Annealing technique, an algorithm which is widely applied to combinatorial problems in the field of manufacturing systems. We consider the search for the best set as a second optimisation problem that we solve by a Genetic Algorithm. The performance of our approach is tested in the particular case of backtracking minimisation in a single row machine layout problem for flexible manufacturing systems.
On Costs in Teleworking
Authors: Lindström J. , Rapp B. , Lindström J.
Published: August 2006

This paper introduces a model for analysing costs within a teleworking organization. The approach can be seen as a modified transaction cost approach which considers the opportunity costs of activities. The aim of this approach is to simplify the understanding of the forces behind teleworking with special emphasis on service organizations. Empirical references to teleworking situations in Sweden are given.
A Simulated Annealing Approach to the Railroad Freight Transportation Design Problem
Authors: Marín Á. , Salmerón J.
Published: August 2006

The tactical planning to determine the frequency of trains and the routing of freight cars is modeled as an integer piecewise linear programming. The optimization model takes into account the interaction between trains and cars. An algorithm based on simulated annealing has been implemented to solve the model. Computational experience for small and medium networks is presented.
Building Linear Programming Models from Structural Model Components
Authors: Binbasioglu M.
Published: August 2006

Model management research investigates the formulation, analysis and interpretation of models. This paper focuses on the formulation aspects of modeling so that the task can be supported by decision support systems (DSS) environments. Given the knowledge intensive nature of the formulation process, the development of a modeling tool requires explicating the knowledge pertaining to modeling. This involves comprehending not only the static knowledge about model components (e.g. decision variables, coefficients, associated indices and constants), but also the process knowledge required to construct models from model pieces. The proposed top‐down approach configures equations by exploiting the structural modeling knowledge inherent in equation components. The possible representation of equations at various abstraction levels is introduced, the aim being to uncover the structural model components together with the process knowledge required for their appropriate configuration. As part of developing this conceptual model, the role of semantic and syntactic information in model building is investigated. The paper proposes an approach where the formulation semantics are captured as a simple ‘action‐resource’ view which composes models by identifying and piecing together the equation components. The process of equation construction is illustrated with examples from the linear programming (LP) modeling domain. The proposed top‐down approach is contrasted with a bottom‐up method.
Optimal Routing Designs in Self‐healing Communications Networks
Authors: Saniee I.
Published: August 2006

Self‐healing communication networks that allow re‐routing of demands through switching processes at designated nodes are studied. It is shown how network utilization, demand throughput and reliability of such networks can be studied simultaneously to achieve an optimal design for all three. This is done through a max–min–max multi‐commodity network flow formulation of the routing problem in which it is ensured that maximum network throughput is achieved with minimum loss of demands that are blocked due to single switching node failures. It is shown that a node‐path linear programming approximation to the multi‐commodity network flow formulation solves the problem for medium and large network sizes in moderate computational times.
A New Composite Algorithm for Clustering Problems
Authors: Torki A. , Yajima Y. , Enkawa T.
Published: August 2006

This paper presents a composite algorithm for solving a class of clustering problems. A quadratic programming formulation of these problems is considered to be solved by the proposed algorithm. In this algorithm a class of non‐convex optimization techniques is applied to an approximated variation of the problem and subsequently a local search scheme is incorporated for the final improvement of obtained solutions. The efficiency of the proposed algorithm is evaluated in comparison with Simulated Annealing and Tabu Search algorithms by exploiting a series of real life data from the literature as well as randomly generated data.
A Rural Electrification Expansion Model
Authors: Smith R.A. , Mesa O.J.
Published: August 2006

In Colombia, power companies with capacity greater than 100 MW pay royalties over gross sales for rural electrification programs. These contributions are collected by regional development corporations (RDC) with a jurisdiction over the area where the generation projects are located. To that end, the RDC need to define a plan for rural electrification in the regions. A mixed integer linear programming model was developed to define rural electrification programs for Colombian regions. In this model several objectives are considered. Objectives such as economic efficiency, minimum municipal electricity coverage, municipal electricity development priorities and some others are included in the model. The ε‐constant multiobjective methodology is used to solve this problem in which the economic efficiency objective is used as the objective function and the other objectives are stated as constraints. In this case trade‐off curves between objectives can be developed to show how much of one objective has to be sacrificed to improve the other objective. These trade‐off curves are the main decision tool for decision makers. The proposed model is used to define a rural electrification program for a Colombian region. The trade‐off curves show that the number of households covered with electricity diminish when, beside the economic efficiency objective, other objectives are considered. Some conclusions and recommendations are presented.
The Location of Public Schools: Evaluation of Practical Experiences
Authors: Pizzolato N.D. , da Silva H.B. Fraga
Published: August 2006

This paper discusses practical experiences resulting from the use of Operations Research techniques for the location of elementary public schools in large urban settings. The experiences reported are based on two counties of the metropolitan area of Rio de Janeiro, Brazil. In these relatively poor areas walking is the most common means of traveling to school, and the ideal location is the one that minimizes the sum of the overall residence‐to‐school distances. The model used was the uncapacitated p‐median, but current capacities of existing schools have been introduced in the interpretation of the results. In both counties, the study first evaluated the existing spatial distribution of schools and then proceeded to propose their ideal location. Both analyses lead to short and long‐run managerial suggestions. A description of the practical status of the study is also included.
Implementing a Real Option Model for Valuing an Undeveloped Oil Field
Authors: Cortazar G. , Schwartz E.S.
Published: August 2006

We present a no arbitrage model for evaluating an undeveloped oil field and its numerical solution and implementation. The model assumes stochastic, but mean reverting, risk adjusted oil spot prices, and includes a timing investment option. The results of using this real options model for evaluating a case study of an undeveloped oil field show that a significant fraction of the oil field value may be provided by the flexibility of delaying development investment, and that this flexibility value decreases as oil price increases. Also the critical price for developing decreases with the available time to develop. We illustrate the use that practitioners could make of the real option methodology to value oil contingent reserves by presenting a user friendly computer program with graphical interface. This implementation could help petroleum companies to use this sophisticated valuation approach that could otherwise be of little practical relevance.
Some Selected Topics in Experimental Economics
Authors: Leopold‐Wildburger U.
Published: August 2006

This paper presents a new tendency and method of analysis in Operations Research and economics respectively. It does not only rely exclusively on the optimization approach, but is concerned with a realistic description and successful explanation of the real economic behavior with the help of experimental economics. This will be exemplified in terms of three toptics of laboratory experimentation which have been conducted by the author: bargaining behavior, economic stabilization, and forecasts as representativeness heuristics. Good predictors and generally valid heuristics can be given for the outcomes of the experiments in all three fields of research.
Exploiting Airline Reservation Technologies to Improve Navy Training Management
Authors: Wang Y. , Folchi J. , Blanco T.A. , Lath S. , White R.J. , Burns L.
Published: August 2006

The Navy trains hundreds of thousands of students every year. For Navy training, yield management means offering the right school seats to the right customers (e.g. active duty, reservists, foreign nationals) at the right time to maximize fleet readiness. The yield management methods will permit the Navy to make the best use of its limited training resources. This paper discusses the yield management technologies that will be tightly integrated into the Navy's new on‐line training seat reservation system.
Selection of Vehicle Routing Heuristic Using Neural Networks
Authors: Tuzun D. , Magent M.A. , Burke L.I.
Published: August 2006

Due to its combinatorial structure, the vehicle routing problem has been attacked by many heuristic solution approaches. Given the large number of available heuristics, selecting the best heuristic for a particular problem poses its own kind of difficulty. This study uses a simple neural network approach to select the best heuristic for a VRP instance according to its basic characterstics. The approach has been trained and tested on a large test bed which covers problems with a wide variety of characterstics. It was also tested on a set of benchmark problems from the literature. For these problems, a simple procedure was used to extract the problem characterstics from the problem data. Statistical analysis reveals that the performance of each heuristic is affected differently by the problem characterstics. Neural network results for both test sets show that our approach is capable of selecting the best algorithm for a given VRP instance.