bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of negative penalty functions in constrained variational problems
Authors: Ilanko Sinniah 
Published: October 2002

AbstractA major drawback of the penalty function method in solving constrained variational problems is the difficulty in choosing suitable penalty parameters that are large enough to effect a constraint but small enough to avoid computational problems. This problem stems from the fact that the appropriate penalty value is normally found by a trial and error process by gradually increasing the parameter until the results converge numerically. In this paper, it is shown that the constrained solution for the deflection of a beam is bounded by results from mathematical models using positive and negative penalty parameters. If this is true in general, any error due to the use of penalty functions in solving a variational problem may be determined and controlled by using positive and negative values for the penalty parameter. Copyright © 2002 John Wiley & Sons, Ltd.
Organizational emergence in networked collaboration
Authors: Hameri Ari‐Pekka , Puittinen Mikael , Syrjälahti Mikko 
Published: October 2002

AbstractResearch on complex adaptive systems has generated several conceptual parables to explain systems with emergent behaviour. One prominent use for terms such as self‐organization, evolutionary trajectories, co‐evolution and punctuated equilibrium has been in understanding human organizations. In such systems, emergent behaviour is demonstrated in novel structures, processes and spin‐offs that cannot be explained just by studying single components of the organization and the intelligence embedded in them. Instead of solely exploiting the qualitative explanatory power of the evolutionary concepts, this paper focuses also on quantitative methods to track emergent behaviour in a globally distributed, constantly fluctuating and highly networked project organization. The underlying case is that of CERN (CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, the Russian Federation, Turkey, Yugoslavia (status suspended after the UN embargo, June 1992), the European Commission and UNESCO have observer status.) and its decade long accelerator project, which strongly relies on electronic communication and networking to achieve its major objectives due to be accomplished by the year 2006. By using time series and self‐organizing maps to analyse the global interaction among project groups and individuals the paper provides new insight to the understanding of emergent behaviour in human organizations. The key result of the study concerns the rigid deep structure of each case organization that seems to remain intact for the duration of the whole project. Copyright © 2002 John Wiley & Sons, Ltd.
Prospects for therapeutic vaccination with glatiramer acetate for neurodegenerative diseases such as Alzheimer's disease
Authors: Schwartz Michal , Kipnis Jonathan 
Published: October 2002

AbstractNeurodegenerative diseases, whatever their primary causes, are characterized by certain common features, one of which is their self‐perpetuating nature. The ongoing progression of the disorder is due to the effects of destructive self‐compounds, whose presence in the tissues is an outcome of the early phase of the disease and which gradually destroy remaining functional neurons. Studies in our laboratory have led to the recent formulation of a novel concept of protective autoimmunity as the body's mechanism of defense against these destructive self‐compounds. This autoimmune response to central nervous system (CNS) insults is mediated by T‐cells and presumably operates by activating and regulating local microglia and infiltrating macrophages (inflammatory response) to carry out their function of clearing destructive material from the tissue at risk. We suggest that a well‐controlled autoimmunity counteracts and overcomes the destructive effects of the potentially harmful self‐compounds, at the cost of some loss of tissue. An additional risk to the individual is the induction of an autoimmune disease, which is likely to occur if the autoimmune response is malfunctioning. An optimal balance of the various factors will lead to an outcome of maximal benefit at minimal cost to the tissue. A procedure for safely boosting the autoimmune response, by vaccination with a weak self‐crossreactive antigen such as glatiramer acetate (also known as Cop‐1) was found to protect rats from glutamate toxicity, a major mediator of the spread of damage and a well‐known causative factor in neurodegenerative disorders. Cop‐1, when administered according to a different regimen, is an FDA‐approved drug for the treatment of multiple sclerosis. Different formulations of the same drug can therefore be used to treat two extreme manifestations of chronic degenerative diseases of the CNS. Drug Dev. Res. 56:143–149, 2002. © 2002 Wiley‐Liss, Inc.
Beta‐sheet breaker strategy for the treatment of Alzheimer's disease
Authors: Adessi Céline , Soto Claudio 
Published: October 2002

AbstractAlzheimer's disease is a degenerative disorder of the brain for which there is no cure or effective treatment. Recent studies suggest that cerebral amyloid plaques play a central role in the pathogenesis of the disease. An attractive therapeutic strategy for Alzheimer's disease is to block the early steps of misfolding and aggregation of the soluble amyloid‐beta peptide. We have engineered synthetic β‐sheet breaker peptides to bind amyloid‐β peptide, stabilize the normal conformation, and destabilize the β‐sheet rich structure that leads to the formation of amyloid plaques. Results in vitro, in cell culture, and in vivo suggest that β‐sheet breaker peptide may be useful for blocking the process of cerebral amyloid deposition. Chemical modifications were introduced into the active peptides to improve their pharmacological properties. It remains to be proved that inhibition of the pathway leading to amyloid plaque deposition could be beneficial for the therapeutic treatment of Alzheimer's disease. Drug Dev. Res. 56:184–193, 2002. © 2002 Wiley‐Liss, Inc.
A model of equilibrium bed topography for meander bends with erodible banks
Authors: Darby Stephen E. , Delbono Ivana 
Published: October 2002

AbstractChannel curvature produces secondary currents and a transverse sloping channel bed, along which the depth increases towards the outer bank. As a result deep pools tend to form adjacent to the outer bank, promoting bank collapse. The interaction of sediment grains with the primary and secondary flow and the transverse sloping bed also causes meanders to move different grain sizes in different proportions and directions, resulting in a consistent sorting pattern. Several models have been developed to describe this process, but they all have the potential to over‐predict pool depth because they cannot account for the influence of erodible banks. In reality, bank collapse might lead to the development of a wider, shallower cross‐section and any resulting flow depth discrepancy can bias associated predictions of flow, sediment transport, and grain‐size sorting. While bed topography, sediment transport and grain sorting in bends will partly be controlled by the sedimentary characteristics of the bank materials, the magnitude of this effect has not previously been explored. This paper reports the development of a model of flow, sediment transport, grain‐size sorting, and bed topography for river bends with erodible banks. The model is tested via intercomparison of predicted and observed bed topography in one low‐energy (5·3 W m−2 specific stream power) and one high‐energy (43·4 W m−2) study reach, namely the River South Esk in Scotland and Goodwin Creek in Mississippi, respectively. Model predictions of bed topography are found to be satisfactory, at least close to the apices of bends. Finally, the model is used in sensitivity analyses that provide insight into the influence of bank erodibility on equilibrium meander morphology and associated patterns of grain‐size sorting. The sensitivity of meander response to bank cohesion is found to increase as a function of the available stream power within the two study bends. Copyright © 2002 John Wiley & Sons, Ltd.
Temporal patterns of suspended sediment yield following moderate to extreme hydrological events recorded in varved lacustrine sediments
Authors: Lamoureux Scott 
Published: October 2002

AbstractA 487‐year annually laminated (varved) sediment record from Nicolay Lake, Cornwall Island, in the Canadian High Arctic was evaluated to determine the impact that years with high sediment yields had on sediment yields in subsequent years. All of the 40 largest years showed evidence for increased sediment yield in the subsequent 10–30 years. The positive anomalies in lagging years were approximately scaled according to the size of the initiating year, although many intermediate years (25‐ to 100‐year recurrence) showed weak or variable responses. The smallest events considered (10‐ to 25‐year recurrence) showed a consistent, but low‐amplitude response. Additionally the 10‐year events revealed frequent negative sediment yield anomalies in the preceding decade. This behaviour was interpreted as a frequent sediment activation cycle initiated by the modest year, and leading to sediment yield hysteresis lasting 15–25 years. The largest years (greater than 50‐year recurrence) showed consistently above‐average sediment yields in the preceding decade, in part due to the frequent occurrence of moderate (Q10) years. It is hypothesized that temporary storage of sediment and previous initiation of erosion sites resulted in extraordinary sediment yields during intense summer rainfall events. This study demonstrates the potential use of varved lake sediment records to improve our understanding of long‐term sediment dynamics. These records present an opportunity to further develop and test sediment dynamic and routing models to gain insight into the interaction of time and space in fluvial and sediment delivery processes. Copyright © 2002 John Wiley & Sons, Ltd.
Highly accurate solutions of the bifurcation structure of mixed‐convection heat transfer using spectral method
Authors: Selmi M. , Nandakumar K. 
Published: October 2002

AbstractThis paper is concerned with producing highly accurate solution and bifurcation structure using the pseudo‐spectral method for the two‐dimensional pressure‐driven flow through a horizontal duct of a square cross‐section that is heated by a uniform flux in the axial direction with a uniform temperature on the periphery. Two approaches are presented. In one approach, the streamwise vorticity, streamwise momentum and energy equations are solved for the stream function, axial velocity, and temperature. In the second approach, the streamwise vorticity and a combination of the energy and momentum equations are solved for stream function and temperature only. While the second approach solves less number of equations than the first approach, a grid sensitivity analysis has shown no distinct advantage of one method over the other. The overall solution structure composed of two symmetric and four asymmetric branches in the range of Grashof number (Gr) of 0–2 × 106 for a Prandtl number (Pr) of 0.73 has been computed using the first approach. The computed structure is comparable to that found by Nandakumar and Weinitschke (1991) using a finite difference scheme for Grashof numbers in the range of 0–1×106. The stability properties of some solution branches; however, are different. In particular, the two‐cell structure of the isolated symmetric branch that has been found to be unstable by the study of Nandakumar and Weinitschke is found to be stable by the current study. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical study of flows of complex fluids between eccentric cylinders using transformation functions
Authors: Radu Grecov Dana , Clermont Jean‐Robert 
Published: October 2002

AbstractIn this paper, we investigate fluid flows between eccentric cylinders by means of two stream‐tube analyses. The first method considers a one‐to‐one global transformation function that allows the physical domain to be transformed into a mapped domain, used as computational domain, that involves concentric streamlines. The second approach uses local transformations and domain decomposition techniques to deal with mixed flow regimes. Both formulations are particularly adapted for handling time‐dependent constitutive equations, since particle‐tracking problems are avoided. Mass conservation is verified in both formulations and the relevant numerical procedure can be carried out using simple meshes built on the mapped streamlines. Fluids obeying anelastic and viscoelastic constitutive equations are considered in the calculations. The numerical results are consistent with those in the literature for the flow rates tested. Application of the method to the K‐BKZ memory‐integral constitutive equation highlights significant differences between the model predictions and those provided by more simple rheological models. Copyright © 2002 John Wiley & Sons, Ltd.
Homocysteine in neuropsychiatric disorders of the elderly
Authors: Reutens Sharon , Sachdev Perminder 
Published: October 2002

AbstractObjectiveThere is increasing interest in homocysteine as a risk factor for neuropsychiatric disorders such as stroke, dementia, depression and Parkinson's disease. This article reviews the current literature on the relationship between homocysteine and these disorders to ascertain if any clinical recommendations can be made.MethodA MEDLINE and EMBASE search was made for English language publications between 1966 and 2002 using the search terms ‘Homocysteine’ and ‘Stroke’, ‘Dementia’, ‘Vascular Dementia’, ‘Alzheimer's dementia’, ‘Cognition disorders or cognitive decline or memory disorders’, ‘Depression or depressive disorders’ or ‘Parkinson's disease’. In addition, individual articles were hand searched for relevant references.ResultsCross‐sectional studies consistently suggest that elevated homocysteine increases the risk of stroke, and may also increase the risk of leukoariosis, vascular dementia (VaD), cognitive impairment and Alzheimer's disease (AD). Longitudinal studies of homocysteine as a risk factor are few and inconsistently supportive of these associations. No intervention trials to determine the effect of lowering homocysteine levels have yet been published. The pathological mechanisms for homocysteine‐mediated disease await complete elucidation. Mild hyperhomocysteinemia is common in the elderly population, and folate supplementation can decrease homocysteine levels.ConclusionThe epidemiological evidence for homocysteine as a risk factor for neuropsychiatric disease is an emerging area of great interest. Screening the population for hyperhomocysteinemia cannot be recommended at this stage, but individuals at increased risk of cerebrovascular disease or cognitive impairment should be investigated and treated for elevated homocysteine levels. Copyright © 2002 John Wiley & Sons, Ltd.
Understanding and optimizing multisource feedback
Authors: Atwater Leanne E. , Waldman David A. , Brett Joan F. 
Published: October 2002

AbstractThis article integrates the most recent research results on the topic of multisource feedback with what
researchers have learned over the years about performance feedback in general. We believe that this review and set
of recommendations represent the state of the art at this time. We provide practitioners with new ideas about how
to continue to improve the multisource feedback process in their organizations. We also suggest ideas for feedback
providers and facilitators about how to maximize the success of the feedback process. Additionally, we provide
“food for thought” for researchers concerning ideas for future research. © 2002 Wiley
Periodicals, Inc.
In the trenches at the talent wars: competitive interaction for scarce human resources
Authors: Gardner Timothy M. 
Published: October 2002

AbstractA number of indicators suggest that the social norms that once deterred labor market competitors from hiring or
“poaching” each others' employees are breaking down. This study explores the competitive
interaction that results when one firm attempts to hire employees from a competing firm (known as “talent
raiding”). Results suggest that attributes of the raiding firm, the targeted firm, and targeted human
capital will affect how a targeted firm responds to a talent raid. The study suggests a number of tactics raiding
firms can use to avoid retaliation and suggests tactics targeted firms can use to repel would‐be talent
raiders. © 2002 Wiley Periodicals, Inc.
Anti‐epidermal growth factor receptor‐antibody therapy for treatment of breast cancer
Authors: Solbach Christine , Roller Marc , Ahr Andre , Loibl Sibylle , Nicoletti Maria , Stegmueller Manfred , Kreysch Hans‐Georg , Knecht Rainald , Kaufmann Manfred 
Published: October 2002

AbstractRecent studies demonstrated that tumors overexpressing the epidermal growth factor receptor (EGF‐R, erbB‐1) are associated with poor clinical outcome. This led to the development of a variety of monoclonal antibodies targeting the extracellular domain of this receptor tyrosine kinase. The aim of our study was the evaluation of anti‐EGF‐R antibody EMD 55900 therapy for treatment of breast cancer. On the basis of 299 tumor specimens derived from breast cancer patients, we investigated EGF‐R expression and generated a collective of primary xenotransplants in athymic nude mice. The animals received therapy in 2 treatment schedules to investigate the therapeutic response in early stages of tumor formation as well as on well established tumors. Using 6 different tumors with EGF‐R expression levels between 10–300 fmol/mg total protein, we found a therapeutic effect when the EGF‐R expression of the tumors was at least 40 fMol/mg. On the basis of these experimental data and our EGF‐R expression analysis of breast cancer specimens, we conclude that up to 15% of breast cancer patients could benefit from this monotherapy with EMD 55900. © 2002 Wiley‐Liss, Inc.
Biostability of electrically conductive polyester fabrics: An in vitro study
Authors: Jiang Xiaoping , Tessier Dominic , Dao Lê H. , Zhang Ze 
Published: October 2002

AbstractThe biostability of a series of polypyrrole (PPy)‐coated polyester fabrics was investigated in an in vitro model. PPy‐coated sample fabrics were incubated in saline at 37°C for 1 and 2 weeks. After each period of incubation, the surface electrical resistivity of the sample fabrics was measured to monitor the changes caused by the incubation. Redoping was then performed by immersing the sample fabrics in a 1N HCl solution at room temperature for 30 min, which was followed by another measurement of the surface resistivity. The surface morphology of the sample fabrics was observed by scanning electron microscopy. The surface chemical composition of the fabrics and the oxidation of nitrogen in PPy were measured with X‐ray photoelectron spectroscopy. The surface electrical resistivity of the PPy‐coated fabrics was found to increase with the progress of incubation, which was mainly caused by dedoping and uptake of oxygen. This increase was nonlinear and accelerated with time. The surface resistivity of most of the samples was retained in the range of 103–104 Ω/square after 1 week of incubation, which was considered suitable for short‐term electrical stimulation applications. Physical deterioration represented by the cracking and delamination of the PPy coating was occasionally observed on the sample fabrics showing the most significant increase of resistivity. Further improvement of the stability of conductivity is highly desirable. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 507–513, 2002
Virological and immunological effects of salvage therapy following treatment interruption and a shift in HIV‐1 resistance genotype
Authors: Izopet Jacques , Souyris Corinne , Sandres‐Sauné Karine , Puissant Bénédicte , Obadia Martine , Pasquier Christophe , Puel Jacqueline , Blancher Antoine , Massip Patrice 
Published: October 2002

AbstractThe circulating human immunodeficiency virus type 1 (HIV‐1) population of patients in whom many prior therapy regimens have failed often undergo a shift from a drug‐resistant virus to a wild‐type virus following interruption of treatment. This study analyses the virological and immunological effects of salvage therapy following treatment interruption and a shift from a drug‐resistance genotype. Twenty‐one HIV‐1 infected patients who had genotype reversion by population‐based sequencing after 3 months of treatment interruption were given a new salvage regimen consisting of 3–5 drugs selected according to their treatment history. Seven (33%) of 21 patients who had fewer than 200 HIV‐1 RNA copies/ml until month 12 were defined as virological responders. Four patients were transient responders and 10 were nonresponders. The virological responders were more frequently CDC group A and had higher CD4 + T lymphocyte counts at the time of treatment resumption. The peripheral blood T CD4 + and T CD8 + lymphocyte populations of the patients declined significantly during treatment interruption. Only virological responders showed significant increases in their CD4 + T lymphocyte count 12 months after treatment resumption and these counts rapidly returned to pre‐interruption baseline values in most of these patients. Treatment interruption could be useful for optimising salvage therapy for patients previously given many failing regimens. However, controlled trials are needed to assess the clinical benefit of this strategy. J. Med. Virol. 68:305–310, 2002. © 2002 Wiley‐Liss, Inc.
Improved microvessel repair: Laser welding with an anti‐thrombotic solder
Authors: Stewart Robert B. , Bass Lawrence S. , Thompson Jeffrey K. , Nikoi Naa Dei , Becker Glenn , Kung Robert T.V. 
Published: October 2002

AbstractBackground and ObjectivesConcentrated protein solutions can be used as thermally polymerized solders in laser welding. Solders supplemented with biologically active chemicals may provide in situ drug delivery for localized therapeutics. These studies characterize a serum albumin (SA) solder containing heparin, designed to reduce microvascular thrombosis rates.Study Design/Materials and MethodsSamples of heparin added to 30% SA to obtain heparin‐to‐albumin molar ratios (HAMR) of 4:1 and 2:1 were thermally polymerized, and heparin release into saline was measured. Using a rat thrombosis model, patency was determined for suture, and 0 U/ml (control), 2.5 U/ml, 50 U/ml heparin solder repairs.ResultsHeparin release was five times higher for 4:1 than 2:1 HAMR solder acutely, but was equivalent after 2 days. Animal patency rates were: 50% suture, 0% control, 50% low heparin, 66% high heparin (P < 0.05 vs. control).ConclusionsSolders incorporating heparin should provide in situ anti‐thrombotic therapy reducing the risk of microvascular thromboses. Lasers Surg. Med. 31:36–40, 2002. © 2002 Wiley‐Liss, Inc.