bluuebunny/crossref_metadata_2025_split huggingface dataset:
From mixed finite elements to finite volumes for elliptic PDEs in two and three dimensions
Authors: Younes Anis , Ackerer Philippe , Chavent Guy 
Published: December 2003

AbstractThe link between Mixed Finite Element (MFE) and Finite Volume (FV) methods applied to elliptic partial differential equations has been investigated by many authors. Recently, a FV formulation of the mixed approach has been developed. This approach was restricted to 2D problems with a scalar for the parameter used to calculate fluxes from the state variable gradient. This new approach is extended to 2D problems with a full parameter tensor and to 3D problems. The objective of this new formulation is to reduce the total number of unknowns while keeping the same accuracy. This is achieved by defining one new variable per element.For the 2D case with full parameter tensor, this new formulation exists for any kind of triangulation. It allows the reduction of the number of unknowns to the number of elements instead of the number of edges. No additional assumptions are required concerning the averaging of the parameter in hetero‐ geneous domains. For 3D problems, we demonstrate that the new formulation cannot exist for a general 3D tetrahedral discretization, unlike in the 2D problem. However, it does exist when the tetrahedrons are regular, or deduced from rectangular parallelepipeds, and allows reduction of the number of unknowns. Numerical experiments and comparisons between both formulations in 2D show the efficiency of the new formulation. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical solution of the Helmholtz equation with high wavenumbers
Authors: Bao Gang , Wei G. W. , Zhao Shan 
Published: December 2003

AbstractThis paper investigates the pollution effect, and explores the feasibility of a local spectral method, the discrete singular convolution (DSC) algorithm for solving the Helmholtz equation with high wavenumbers. Fourier analysis is employed to study the dispersive error of the DSC algorithm. Our analysis of dispersive errors indicates that the DSC algorithm yields a dispersion vanishing scheme. The dispersion analysis is further confirmed by the numerical results. For one‐ and higher‐dimensional Helmholtz equations, the DSC algorithm is shown to be an essentially pollution‐free scheme. Furthermore, for large‐scale computation, the grid density of the DSC algorithm can be close to the optimal two grid points per wavelength. The present study reveals that the DSC algorithm is accurate and efficient for solving the Helmholtz equation with high wavenumbers. Copyright © 2003 John Wiley & Sons, Ltd.
Implicit plane stress algorithm for multilayer J2‐plasticity using the Prager–Ziegler translation rule
Authors: Montáns Francisco J. 
Published: December 2003

AbstractA totally implicit algorithm for plane stress multilayer plasticity is presented. The algorithm presents the plane stress version of the 3D/plane strain model for multilayer plasticity presented in a previous work. As in the 3D/plane strain case, the model is consistent with the principle of maximum dissipation and it may be considered as an extension of classical J2‐plasticity for anisotropic non‐linear kinematic behaviour preserving Masing's rules. In order to obtain the asymptotic second‐order convergence of the Newton algorithm, the consistent tangent moduli are also given. Copyright © 2003 John Wiley & Sons, Ltd.
Finite element methods for the non‐linear mechanics of crystalline sheets and nanotubes
Authors: Arroyo M. , Belytschko T. 
Published: December 2003

AbstractThe formulation and finite element implementation of a finite deformation continuum theory for the mechanics of crystalline sheets is described. This theory generalizes standard crystal elasticity to curved monolayer lattices by means of the exponential Cauchy–Born rule. The constitutive model for a two‐dimensional continuum deforming in three dimensions (a surface) is written explicitly in terms of the underlying atomistic model. The resulting hyper‐elastic potential depends on the stretch and the curvature of the surface, as well as on internal elastic variables describing the rearrangements of the crystal within the unit cell. Coarse grained calculations of carbon nanotubes (CNTs) are performed by discretizing this continuum mechanics theory by finite elements. A smooth discrete representation of the surface is required, and subdivision finite elements, proposed for thin‐shell analysis, are used. A detailed set of numerical experiments, in which the continuum/finite element solutions are compared to the corresponding full atomistic calculations of CNTs, involving very large deformations and geometric instabilities, demonstrates the accuracy of the proposed approach. Simulations for large multi‐million systems illustrate the computational savings which can be achieved. Copyright © 2003 John Wiley & Sons, Ltd.
Managers as knowledge generators: The nature of practitioner‐scholar research in the nonprofit sector
Authors: Salipante Paul , Aram John D. 
Published: December 2003

AbstractAs nonprofit management education develops, it has the opportunity to consider new premises concerning managers' roles. In the design and
practice of traditional management education, managers are assumed to be the ultimate users of knowledge. Less attention is given to educating
managers to be knowledge generators who combine intimate understanding of issues, problems, and settings with established theory and methods. Based on
a discussion of three research projects undertaken in nonprofit settings by participants in a doctoral program for advanced practitioners at the
Weatherhead School of Management at Case Western Reserve University, we describe seven dimensions of practitioner‐scholar inquiry. The pattern
of practitioner‐scholar research that emerges from these research projects is contrasted with two other modes of knowledge production.
Implications for practitioner‐scholar inquiry and for the education of practitioner‐scholars in the nonprofit sector are discussed.
Liability and volunteer organizations: A survey of the law
Authors: Martinez J. Michael 
Published: December 2003

AbstractThe question of how and when liability attaches is one of the most important issues facing volunteer organizations today. The liability issue has
three related components: (1) whether the organization is liable to third parties for acts performed by volunteers, (2) whether the
organization is liable to volunteers who are injured while performing their duties, and (3) whether an individual volunteer is liable for
acts performed while working with a volunteer organization. This article explores each of these issues and suggests effective risk management practices
that can reduce, although not eliminate, liability in most instances.
Leadership in education: Effective U.K. college principals
Authors: Sala Fabio 
Published: December 2003

AbstractCollege leaders face increasing challenges to manage complex responsibilities. They must possess a wide variety of managerial and leadership skills
to be successful in academic environments, which are beginning to resemble more traditional organizational frameworks. The study examined in this
article explored the relationships among managerial style, organizational climate, and several measures of college‐student performance with a
sample of British further education college principals (similar to U.S. community college presidents). While considering the influence of
various background factors, such as the size of the college, student funding, and years of experience, several significant relationships emerged
demonstrating a significant association between principals' managerial behaviors and measures of college and student performance.
Making sense of accountability: Conceptual perspectives for northern and southern nonprofits
Authors: Ebrahim Alnoor 
Published: December 2003

AbstractThis article examines the concept of accountability from various disciplinary lenses in order to develop an integrated understanding of the term. Special attention is devoted to principal—agent perspectives from political science and economics. An integrated framework is developed, based on four central observations. (1) Accountability is relational in nature and is constructed through inter‐ and intraorganizational relationships. (2) Accountability is complicated by the dual role of nonprofits as both principals and agents in their relationships with other actors. (3) Characteristics of accountability necessarily vary with the type of nonprofit organization being examined. (4) Accountability operates through external as well as internal processes, such that an emphasis on external oversight and control misses other dimensions of accountability essential to nonprofit organizations. The analysis draws from the experiences of both Northern and Southern nonprofits, that is, organizations based in wealthy industrialized regions of the world (the global North) and those in economically poorer areas (the South).
The understanding of internal control principles by pastors
Authors: Duncan John B. , Stocks Morris H. 
Published: December 2003

AbstractAlthough the concept of internal control is as relevant to churches as it is to profit‐seeking organizations, many authors have indicated that
churches typically have weak systems of internal control. Pastors usually serve in the position of chief professional officer of their churches, and the
implementation and maintenance of an adequate system of internal control is ultimately the responsibility of management. This study is a preliminary
effort to determine whether pastors understand general principles of internal control and are able to recognize strengths and weaknesses in systems of
internal control. The results show that pastors have a reasonable ability to recognize strengths and weaknesses in internal control systems in
churches.
Nonprofit management in Europe and Asia
Authors: Young Dennis R. 
Published: December 2003

AbstractThe State and NGOs: Perspective from Asia, edited by Shinichi Shigetomi. Singapore: Institute of Southeast Asia Studies, 2002. $28.50
cloth.The Emergence of Social Enterprise, edited by Carlo Borzaga and Jacques Defourny. New York: Routledge, 2001. $120.00 cloth.
Issues in applying recent CPMP ‘Points to Consider’ and FDA guidance documents with biostatistical implications
Authors: Phillips Alan , Ebbutt Alan , France Lesley , Morgan David , Ireson Mick , Struthers Lesley , Heimann Guenter 
Published: December 2003

AbstractThe International Conference on Harmonisation guideline ‘Statistical Principles for Clinical Trials’ was adopted by the Committee for Proprietary Medicinal Products (CPMP) in March 1998, and consequently is operational in Europe. Since then more detailed guidance on selected topics has been issued by the CPMP in the form of ‘Points to Consider’ documents. The intent of these was to give guidance particularly to non‐statistical reviewers within regulatory authorities, although of course they also provide a good source of information for pharmaceutical industry statisticians. In addition, the Food and Drug Administration has recently issued a draft guideline on data monitoring committees. In November 2002 a one‐day discussion forum was held in London by Statisticians in the Pharmaceutical Industry (PSI). The aim of the meeting was to discuss how statisticians were responding to some of the issues covered in these new guidelines, and to document consensus views where they existed. The forum was attended by industry, academic and regulatory statisticians. This paper outlines the questions raised, resulting discussions and consensus views reached. It is clear from the guidelines and discussions at the workshop that the statistical analysis strategy must be planned during the design phase of a clinical trial and carefully documented. Once the study is complete the analysis strategy should be thoughtfully executed and the findings reported. Copyright © 2003 John Wiley & Sons, Ltd.
Sample size determination in fixed‐dose combination drug studies
Authors: Sidik Kurex , Jonkman Jeffrey N. 
Published: December 2003

AbstractIn this paper, the application of the intersection–union test method in fixed‐dose combination drug studies is discussed. An approximate sample size formula for the problem of testing the efficacy of a combination drug using intersection–union tests is proposed. The sample sizes obtained from the formula are found to be reasonably accurate in terms of attaining the target power 1−β for a specified β. Copyright © 2003 John Wiley & Sons, Ltd.
Common threads between sample size recalculation and group sequential procedures
Authors: Schwartz Todd A. , Denne Jonathan S. 
Published: December 2003

AbstractSample size recalculation (SSR) methods ensure that a study closely achieves the required power by allowing for the original sample size to be modified through updating misspecified nuisance parameters. Some SSR procedures extend this concept by incorporating information on the estimated treatment difference as well. While group sequential methodology allows for early stopping of a study in the context of repeated hypothesis tests, SSR usually involves the extension of a study to accommodate misspecified design parameters. This work describes these methods and places them in a common framework. Copyright © 2003 John Wiley & Sons, Ltd.
Immunopotentiating properties of Cryptolepis buchanani root extract
Authors: Kaul Anpurna , Bani Sarang , Zutshi Usha , Suri K. A. , Satti N. K. , Suri O. P. 
Published: December 2003

AbstractThe ethanol extract (95%) of the root of the plant Cryptolepis buchanani (EECB) was investigated for immunomodulatory activity in mice and rats. The oral administration of EECB caused signiﬁcant stimulation of the delayed type hypersensitivity (DTH) reaction and humoral antibody production. The oral LD50 was found to be more than 3 g/kg in both rats and mice.
Guarana (Paullinia cupana Mart.) offers protection against gastric lesions induced by ethanol and indomethacin in rats
Authors: Campos A. R. , Barros A. I. S. , Santos F. A. , Rao V. S. N. 
Published: December 2003

AbstractThe effects of guarana (Paullinia cupana) extract were analyzed in rats on acute gastric lesions induced by ethanol and indomethacin and were compared to those produced by caffeine, a methylxanthine. Guarana (50 and 100 mg/kg p.o.) pretreated animals showed a signiﬁcant reduction in the severity of gastric lesions induced by absolute ethanol in a manner similar to caffeine (20 and 30 mg/kg p.o.). Against indomethacin‐induced gastric ulceration, guarana at a higher dose offered signiﬁcant protection but caffeine was ineffective at the doses tested. In 4 h pylorus‐ligated rats, both guarana and caffeine caused signiﬁcant diminution in the gastric secretory volume as well as the total acidity. Gastrointestinal transit in mice was not signiﬁcantly affected by either of these agents. These ﬁndings indicate that guarana has a gastroprotective property that needs further elucidation as regards to its mechanism. Copyright © 2003 John Wiley & Sons, Ltd.
Treatment of patients with arthrosis of hip or knee with an aqueous extract of Devil's Claw (Harpagophytum procumbens DC.)
Authors: Wegener Tankred , Lüpke Niels‐Peter 
Published: December 2003

AbstractPreparations made from the secondary tubers of Devil's claw (Harpagophytum procumbens) are successfully used in patients with rheumatic diseases (arthrosis and low back pain). In order to add data on the efﬁcacy and long‐term safety of an aqueous extract (Dolotefﬁn™; 2400 mg extract daily, corresponding to 50 mg harpagoside), which has been tested successfully in patients with low back pain, an uncontrolled multicentre drug surveillance study for about 12 weeks was conducted in 75 patients with arthrosis of the hip or knee. To standardize the assessment of treatment effects, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index (10 point scale) as well as the 10 cm VAS pain scale were used. The results of the study revealed a strong reduction of pain and the symptoms of osteoarthritis. There was a relevant improvement of each WOMAC subscale as well as of the total WOMAC index: 23.8% for the pain subscale, 22.2% for the stiffness subscale and 23.1% for the physical function subscale. The WOMAC total score was reduced by 22.9%. VAS pain scores were decreased by 25.8% for actual pain, 25.2% for average pain, 22.6% for worst pain and 24.5% for the total pain score. The physicians reported a continuous improvement in typical clinical ﬁndings such as 45.5% for pain on palpation, 35% for limitation of mobility and 25.4% for joint crepitus. Only two cases of possible adverse drug reactions were reported (dyspeptic complaints and a sensation of fullness). Although this was an open clinical study, the results suggest that this Devil's claw extract has a clinically beneﬁcial effect in the treatment of arthrosis of the hip or knee. Copyright © 2003 John Wiley & Sons, Ltd.
Anti‐sickling potential of a Nigerian herbal formula (ajawaron HF) and the major plant component (Cissus populnea L. CPK)
Authors: Moody J. O. , Ojo O. O. , Omotade O. O. , Adeyemo A. A. , Olumese P. E. , Ogundipe O. O. 
Published: December 2003

AbstractThe anti‐sickling activities of the extracts of the roots of a plant Cissus populnea L. (CPK) (a major constituent of a herbal formula Ajawaron HF used in the management of sickle cell disease in south‐west Nigeria) has been examined. Phytochemical examination of the extract showed the presence of anthraquinone derivatives, steroidal glycosides and cardiac glycosides. Alkaloids and tannins were completely absent in the CPK extracts. Evaluation of the anti‐sickling activity involved the use of both positive (p‐hydroxybenzoic acid, 5 µg/mL) and negative control (normal saline) for each set of experiments aimed at the inhibition of sodium metabisulphite‐induced sickling of the HbSS red blood cells obtained from conﬁrmed non‐crisis state sickle‐cell patients. The chloroform and water partitioned fractions of the cold methanol extracts of CPK exhibited a 62.2% and 52.9% inhibition of sickling, respectively, at 180 min. The herbal formula (HF) aqueous extract showed the highest anti‐sickling activity on a weight by weight basis of all the extracts and fractions tested, giving a 71.4% inhibition of sickling at the end of 180 min incubation when compared with the normal saline control. The maximum percentage inhibition of sickling exhibited by the p‐hydroxybenzoic acid control was 46.0% at 90 min incubation. Copyright © 2003 John Wiley & Sons, Ltd.
Antifungal activity of wogonin
Authors: Pal Mahesh , Joshi Harsha , Kapoor V. P. , Pushpangadan P. , Chaurasia Leena 
Published: December 2003

AbstractThe antifungal activity of the wogonin isolated from Holmskioldia sanguinea Retz was determined on four different fungal organisms. The pure compound wogonin signiﬁcantly inhibited the growth of Aspergillus niger, Penicillium frequentance, P. notatum and Botrytis cinerea, in a concentration dependent fashion, when tested by turbidity and spore germination methods. The effects produced by the compound were compared with the standard antifungal agent griseofulvin. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation of the antimicrobial property of Polyalthia longifolia var. pendula: isolation of a lactone as the active antibacterial agent from the ethanol extract of the stem
Authors: Faizi Shaheen , Mughal Najma Rasool , Khan Rashid Ali , Khan Shakeel Ahmed , Ahmad Aqeel , Bibi Nazia , Ahmed Shaheena Anwar 
Published: December 2003

AbstractBioassay guided fractionation of the ethanolic extract of Polyalthia longifolia var. pendula stem, which showed promising antibacterial activity against thirteen Gram‐positive and nine Gram‐negative organisms, furnished (3S,4R)‐3,4,5‐trihydroxypentanoic acid‐1,4‐lactone (1) as the active principle. The structure of (1) was established by UV, IR, mass, 1H and 13C NMR as well as 2D NMR spectral studies and the formation of its acetate (1a). On acetylation activity of (1) was markedly reduced. It is synthetically well known and only recently isolated from two plants, however, its antimicrobial activity was not reported earlier. The extract, fractions and pure compounds did not show any remarkable activity against fungi and Mycobacterium fortuitum, and M. smegmatis. Copyright © 2003 John Wiley & Sons, Ltd.
Mangifera indica L. extract (Vimang) and mangiferin modulate mouse humoral immune responses
Authors: García D. , Leiro J. , Delgado R. , Sanmartín M. L. , Ubeira F. M. 
Published: December 2003

AbstractThe present study investigated the effects of orally administered Vimang (an aqueous extract of Mangifera indica) and mangiferin (the major polyphenol present in Vimang) on mouse antibody responses induced by inoculation with spores of microsporidian parasites. Inoculation induced speciﬁc antibody production with an exponential timecourse, peaking after about one month. Vimang signiﬁcantly inhibited this antibody production from about three weeks post‐inoculation, and most markedly by four weeks post‐inoculation; by contrast, mangiferin had no signiﬁcant effect. Determination of Ig isotypes showed that the IgM to IgG switch began about four weeks post‐inoculation, with IgG2a predominating. Vimang signiﬁcantly inhibited IgG production, but had no effect on IgM. Mangiferin did no affect either IgM or IgG2a, but signiﬁcantly enhanced production of IgG1 and IgG2b. Neither Vimang nor mangiferin enhanced speciﬁc antibody secretion by splenic plasma cells from mice inoculated with microsporidian spores, whether administered in vivo before serum extraction or in vitro to the culture medium. Inoculation with spores induced splenomegaly, which was signiﬁcantly reduced by Vimang and signiﬁcantly enhanced by mangiferin. These results suggest that components of Mangifera indica extracts may be of potential value for modulating the humoral response in different immunopathological disorders. Copyright © 2003 John Wiley & Sons, Ltd.
Radiomodulatory inﬂuence of Rajgira (Amaranthus paniculatus) leaf extract in Swiss albino mice
Authors: Maharwal J. , Samarth R. M. , Saini M. R. 
Published: December 2003

AbstractRadiomodulatory effect of Rajgira leaf extract against 6, 8 and 10 Gy gamma radiation has been evaluated by 30 day survival of Swiss albino mice. Animals of control groups (untreated irradiated) showed diarrhoea, rufﬂed hairs, epilation, facial edema and consistent decrease in body weight. These signs were less severe/absent in experimental groups (Rajgira treated irradiated), and recovery in body weight was also early and faster. Thirty day survivability was 66 per cent in control group, exposed to 6 Gy, whereas no animal survived beyond 14 and 10 days after irradiation with 8 and 10 Gy gamma rays respectively. However, 100, 60 and 25 per cent survivability was observed in experimental groups at 6, 8 and 10 Gy respectively. Regression analysis of survival data showed that the LD50/30 values were 6.33 and 8.62 Gy for control and experimental animals respectively. The dose reduction factor (DRF) was computed as 1.36. A signiﬁcant decrease in GSH content and increase in LPO level was observed in control animals, whereas in Rajgira pretreated irradiated animals the level of GSH was recorded signiﬁcantly higher but LPO level decreased signiﬁcantly. The results from the present study suggest that Rajgira pretreatment provide protection against gamma irradiation in mice. Copyright © 2003 John Wiley & Sons, Ltd.