bluuebunny/crossref_metadata_2025_split huggingface dataset:
The attractor for a nonlinear reaction‐diffusion system in an unbounded domain
Authors: Efendiev Messoud A. , Zelik Sergey V. 
Published: August 2002

AbstractIn this paper the quasi‐linear second‐order parabolic systems of reaction‐diffusion type in an unbounded domain are considered. Our aim is to study the long‐time behavior of parabolic systems for which the nonlinearity depends explicitly on the gradient of the unknown functions. To this end we give a systematic study of given parabolic systems and their attractors in weighted Sobolev spaces. Dependence of the Hausdorff dimension of attractors on the weight of the Sobolev spaces is considered. © 2001 John Wiley & Sons, Inc.
A new approach to variational problems with multiple scales
Authors: Alberti Giovanni , Müller Stefan 
Published: August 2002

AbstractWe introduce a new concept, the Young measure on micropatterns, to study singularly perturbed variational problems that lead to multiple small scales depending on a small parameter ε. This allows one to extract, in the limit ε → 0, the relevant information at the macroscopic scale as well as the coarsest microscopic scale (say εα) and to eliminate all finer scales.To achieve this we consider rescaled functions Rx (t) := x (s + εαt) viewed as maps of the macroscopic variable s ∈ Ω with values in a suitable function space. The limiting problem can then be formulated as a variational problem on the Young measures generated by Rεx. As an illustration, we study a one‐dimensional model that describes the competition between formation of microstructure and highest gradient regularization. We show that the unique minimizer of the limit problem is a Young measure supported on sawtooth functions with a given period. © 2001 John Wiley & Sons, Inc.
A mathematical framework for stochastic climate models
Authors: Majda Andrew J. , Timofeyev Ilya , Vanden Eijnden Eric 
Published: August 2002

AbstractThere has been a recent burst of activity in the atmosphere‐ocean sciences community in utilizing stable linear Langevin stochastic models for the unresolved degrees of freedom in stochastic climate prediction. Here a systematic mathematical strategy for stochastic climate modeling is developed, and some of the new phenomena in the resulting equations for the climate variables alone are explored. The new phenomena include the emergence of both unstable linear Langevin stochastic models for the climate mean variables and the need to incorporate both suitable nonlinear effects and multiplicative noise in stochastic models under appropriate circumstances. All of these phenomena are derived from a systematic self‐consistent mathematical framework for eliminating the unresolved stochastic modes that is mathematically rigorous in a suitable asymptotic limit. The theory is illustrated for general quadratically nonlinear equations where the explicit nature of the stochastic climate modeling procedure can be elucidated. The feasibility of the approach is demonstrated for the truncated equations for barotropic flow with topography. Explicit concrete examples with the new phenomena are presented for the stochastically forced three‐mode interaction equations. The conjecture of Smith and Waleffe [Phys. Fluids 11 (1999), 1608–1622] for stochastically forced three‐wave resonant equations in a suitable regime of damping and forcing is solved as a byproduct of the approach. Examples of idealized climate models arising from the highly inhomogeneous equilibrium statistical mechanics for geophysical flows are also utilized to demonstrate self‐consistency of the mathematical approach with the predictions of equilibrium statistical mechanics. In particular, for these examples, the reduced stochastic modeling procedure for the climate variables alone is designed to reproduce both the climate mean and the energy spectrum of the climate variables. © 2001 John Wiley & Sons, Inc.
On self‐similar singular solutions of the complex Ginzburg‐Landau equation
Authors: Plecháč Petr , Šverák Vladimír 
Published: August 2002

AbstractWe address the open problem of existence of singularities for the complex Ginzburg‐Landau equation. Using a combination of rigorous results and numerical computations, we describe a countable family of self‐similar singularities. Our analysis includes the supercritical nonlinear Schrödinger equation as a special case. We also consider the problem of stability of these singularities. © 2001 John Wiley & Sons, Inc.
Viscosity solutions with shocks
Authors: Giga Yoshikazu 
Published: August 2002

AbstractA solution of single nonlinear first order equations may develop jump discontinuities even if initial data is smooth. Typical examples include a crude model equation describing some bunching phenomena observed in epitaxial growth of crystals as well as conservation laws where jump discontinuities are called shocks. Conventional theory of viscosity solutions does not apply.We introduce a notion of proper (viscosity) solutions to track whole evolutions for such equations in multi‐dimensional spaces. We establish several versions of comparison principles. We also study the vanishing viscosity method to construct a unique global proper solution at least when the evolution is monotone in time or the initial data is monotone in some sense under additional technical assumptions.In fact, we prove that the graph of approximate solutions converges to that of a proper solution in the Hausdorff distance topology. Such a convergence is also established for conservation laws with monotone data. In particular, local uniform convergence outside shocks is proved. © 2001 John Wiley & Sons, Inc.
Managing application complexity in the SAMRAI object‐oriented framework
Authors: Hornung Richard D. , Kohn Scott R. 
Published: August 2002

AbstractA major challenge facing software libraries for scientific computing is the ability to provide adequate flexibility to meet sophisticated, diverse, and evolving application requirements. Object‐oriented design techniques are valuable tools for capturing characteristics of complex applications in a software architecture. In this paper, we describe certain prominent object‐oriented features of the SAMRAI software library that have proven to be useful in application development. SAMRAI is used in a variety of applications and has demonstrated a substantial amount of code and design re‐use in those applications. This flexibility and extensibility is illustrated with three different application codes. We emphasize two important features of our design. First, we describe the composition of complex numerical algorithms from smaller components which are usable in different applications. Second, we discuss the extension of existing framework components to satisfy new application needs. Published in 2002 by John Wiley & Sons, Ltd.
Establishing a molecular continuum in breast cancer DNA microarrays and benign breast disease
Authors: Worsham Maria J. , Pals Gerard , Raju Usha , Wolman Sandra R. 
Published: August 2002

AbstractAlthough the risk of breast cancer for women in the United States is approximately 1 in 9, identification of risk factors and translation of that knowledge into strategies for prevention have been inhibited by poor understanding of disease pathogenesis. A few benign breast proliferations are associated with higher risks of breast cancer, but definition of a preneoplastic morphologic continuum is lacking. If progression from a premalignant state to malignancy is accompanied by genetic changes, then identification in benign breast disease lesions (BBD) of alterations similar to those found in breast cancer should strengthen the perception of BBD as a premalignant condition. Current testing for hereditary breast cancer susceptibility presumes that only women with invasive breast or ovarian cancer are gene carriers. Therefore, neither in situ breast cancer nor atypical hyperplasias are considered clinically as evidence of a breast‐ovarian syndrome, nor are these diagnoses used to predict carrier status within at‐risk families. This reflects lack of evidence that breast cancer develops along a recognized morphologic continuum from precursor lesions.New mutation screening procedures such as DNA microarrays can provide sensitivity, specificity, and high throughput that circumvent limitations imposed on the scope of molecular marker analyses applied to archival resources. We have studied a BRCA1‐mutant individual with loss of the wild type BRCA1 allele in benign breast proliferations. Both her benign and malignant lesions showed molecularly identical TP53 mutations, indicating that significant genetic alterations can occur in BBD and supporting the clonal evolution from BBD to malignancy. Cytometry 47:56–59, 2002. © 2001 Wiley‐Liss, Inc.
Optimizing flow cytometric DNA ploidy and S‐phase fraction as independent prognostic markers for node‐negative breast cancer specimens
Authors: Bagwell C.B. , Clark G.M. , Spyratos F. , Chassevent A. , Bendahl P.‐O. , Stål O. , Killander D. , Jourdan M.L. , Romain S. , Hunsberger B. , Baldetorp B. 
Published: August 2002

AbstractDeveloping a reliable and quantitative assessment of the potential virulence of a malignancy has been a long‐standing goal in clinical cytometry. DNA histogram analysis provides valuable information on the cycling activity of a tumor population through S‐phase estimates; it also identifies nondiploid populations, a possible indicator of genetic instability and subsequent predisposition to metastasis. Because of conflicting studies in the literature, the clinical relevance of both of these potential prognostic markers has been questioned for the management of breast cancer patients. The purposes of this study are to present a set of 10 adjustments derived from a single large study that optimizes the prognostic strength of both DNA ploidy and S‐phase and to test the validity of this approach on two other large multicenter studies. Ten adjustments to both DNA ploidy and S‐phase were developed from a single node‐negative breast cancer database from Baylor College (n = 961 cases). Seven of the adjustments were used to reclassify histograms into low‐risk and high‐risk ploidy patterns based on aneuploid fraction and DNA index optimum thresholds resulting in prognosticPvalues changing from little (P< 0.02) or no significance toP< 0.000005. Other databases from Sweden (n = 210 cases) and France (n = 220 cases) demonstrated similar improvement of DNA ploidy prognostic significance,P< 0.02 toP< 0.0009 andP< 0.12 toP< 0.002, respectively. Three other adjustments were applied to diploid and aneuploid S‐phases. These adjustments eliminated a spurious correlation between DNA ploidy and S‐phase and enabled them to combine independently into a powerful prognostic model capable of stratifying patients into low, intermediate, and high‐risk groups (P< 0.000005). When the Baylor prognostic model was applied to the Sweden and French databases, similar significant patient stratifications were observed (P< 0.0003 andP< 0.00001, respectively). The successful transference of the Baylor prognostic model to other studies suggests that the proposed adjustments may play an important role in standardizing this test and provide valuable prognostic information to those involved in the management of breast cancer patients. Cytometry (Comm. Clin. Cytometry) 46:121–135, 2001. © 2001 Wiley‐Liss, Inc.
Analysis of ultra‐wideband short pulses for radio communications
Authors: Zhang Yan , Geyer Michael E. 
Published: August 2002

AbstractA method to determine the transient waveform of ultra‐wideband (UWB) pulses at various stages of propagation and scattering is developed based on the reconstruction of incident wave and one of the known results for continuous waves. By using this method, the transmitting power of a UWB pulsed dipole antenna and the loss due to rainfall scattering are calculated, and the feasibility for short‐ and moderate‐range communication applications is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Diagnostic value of fine‐needle aspiration in supraclavicular lymphadenopathy: A study of 106 patients and review of literature
Authors: Nasuti Joseph F. , Mehrotra Ravi , Gupta Prabodh K. 
Published: August 2002

AbstractThe simplicity and safety of the fine‐needle aspiration (FNA) make it a useful procedure for the initial evaluation of supraclavicular lymphadenopathy. We analyzed data (106 patients) in combination with the data of three recently published studies (total 301 patients) to make the observations more meaningful. The usefulness of various ancillary techniques such as special histochemical stains (SHC), immunohistochemistry (IHC), and flow cytometry (FCM) in establishing specific diagnoses was also examined. Analysis of the combined data from 407 patients helps to reinforce certain trends observed by previous investigators such as the marked predominance of metastatic carcinoma (63%) over lymphoid malignancies (9%), reactive (19%) and infectious processes (2%), and the tendency of abdominal and pelvic primary carcinomas to metastasize to the left supraclavicular lymph node (SCLN) (88%). In addition, the current study confirms utility of performing IHC, FCM, and SHC on the aspirate material obtained from supraclavicular lymph nodes, because in 19 of the 22 cases (86%), these ancillary techniques provided supplemental diagnostic information critical to patient management. Diagn. Cytopathol. 25:351–355, 2001. © 2001 Wiley‐Liss, Inc.
Clear‐cell sarcoma diagnosis by fine‐needle aspiration: Cytologic, histologic, and ultrastructural features; potential pitfalls; and literature review
Authors: Tong Tommy R. , Chow Tat‐chong , Chan Olivia Wai‐hing , Lee Kam‐cheong , Yeung Sai‐hung , Lam Angus , Yu Chi‐kin 
Published: August 2002

AbstractA definitive diagnosis of clear‐cell sarcoma of soft parts (CCSSP) is possible by fine‐needle aspiration (FNA) biopsy alone. The aspirates are markedly cellular, consisting predominantly of discohesive cells but also of cohesive cells. The cytoplasm is eosinophilic and eccentric. The nuclei are round and contain macronucleoli. CCSSP should be considered when FNA of a soft‐tissue tumor shows uncharacteristically high cellularity and relatively uniform cells with macronucleoli. Cohesion of some tumor cells does not rule out CCSSP. Melanin pigment and cytoplasmic clearing are infrequent and not necessary for the diagnosis. Sufficient material should always be procured for immunohistochemical studies on the cell block. Seven other cases are found in the literature, all correctly diagnosed by FNA. Although it is rare, CCSSP is a highly malignant tumor that can be diagnosed readily by FNA without resorting to incisional biopsy. Diagn. Cytopathol. 2002;26:174–180; DOI 10.1002/dc.10081 © 2002 Wiley‐Liss, Inc.
Cost‐effectiveness of monolayers and human papillomavirus testing compared to that of conventional Papanicolaou smears for cervical cancer screening: Protocol of the study of the French Society of Clinical Cytology
Authors: Cochand‐Priollet Béatrix , Le Galès Catherine , de Cremoux Patricia , Molinié Vincent , Sastre‐Garau Xavier , Vacher‐Lavenu Marie‐Cécile , Vielh Philippe , Coste Joël ,   20 Monolayers French Society of Clinical Cytology Study Group
Published: August 2002

AbstractThe French Society of Clinical Cytology is conducting a study to compare the cost‐effectiveness of monolayers and human papillomavirus (HPV) testing with that of conventional Papanicolaou (Pap) smears for cervical cancer screening. The protocol of this study is presented. It includes 3,000 women who will be evaluated by the three methods (conventional Pap smears, or monolayers with or without HPV testing) and by the reference method: colposcopy followed, in cases with abnormalities, by cervical biopsy. Efficacy or performance of the methods will be compared on the basis of sensitivity. Cost comparisons and cost‐effectiveness modeling will be based on the costs associated with methods themselves and also the costs of “false positives.” This will require specific collection of data concerning the costs of the three methods, as these costs have not previously been accurately documented. Patient recruiting and data collection started in September 1999 and will be complete in June 2000. The first results are expected to be available in spring 2001. Diagn. Cytopathol. 24:412–420, 2001. © 2001 Wiley‐Liss, Inc.
Effects of prior experience with dehydration and water on the time course of dehydration‐induced drinking in weanling rats
Authors: Myers Kevin P. , Hall W. G. 
Published: August 2002

AbstractAlthough cellular dehydration increases oral responding and swallowing of orally infused water in rats as young as 2 days old, it is not until well after the time of weaning that dehydration stimulates immediate water‐seeking and initiation of drinking in situations where the water source must be approached voluntarily. Recent work has shown that the goal‐directed appetitive sequence for drinking—orienting, approaching, and initiating contact with water—matures much later than the more precocial oral licking and swallowing behaviors, and normally comes to be elicited by dehydration only after post‐weaning experience with dry food. In the current experiments we evaluate some critical features of post‐weaning experience with dehydration and drinking, and find that prior experience with initiating drinking while dehydrated, but not experience with dehydration nor water per se, alters the time course of water intake during a subsequent hydrational challenge. The effects of experience are manifested as an increased proportion of water consumed in the early portion of the test, rather than a general increase in total consumption. These findings are consistent with the interpretation that prior experience is necessary for the coordination of water‐oriented appetitive behaviors that lead to the initiation and maintenance of drinking bouts, and provide further evidence for an associative learning account of the acquisition of dehydration‐induced drinking. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 38: 145–153, 2001
Effects of angiotensin II receptor antagonist on endothelial vasomotor function and urinary albumin excretion in type 2 diabetic patients with microalbuminuria
Authors: Tan Kathryn C. B. , Chow Wing‐Sun , Ai Victor H. G. , Lam Karen S. L. 
Published: August 2002

AbstractBackgroundMicroalbuminuria is associated with dysfunction of the vascular endothelium in patients with diabetes mellitus. The objective of the present study was to determine whether treatment with losartan at a dose sufficient to lower urinary albumin excretion was accompanied by an improvement in endothelial function in type 2 diabetic patients with microalbuminuria.MethodsEndothelial function was measured in 80 type 2 diabetic patients with microalbuminuria and 68 non‐diabetic controls using high‐resolution vascular ultrasound. The diabetic patients were randomised to receive either losartan 50 mg daily or placebo in a 6‐month double‐blind study. Urinary albumin excretion and endothelial function were assessed at baseline, 3 and 6 months.ResultsBoth endothelium‐dependent (p<0.01) and ‐independent vasodilation (p<0.01) were significantly impaired in diabetic patients with or without history of hypertension compared to the non‐diabetic controls. At baseline, the losartan‐ and placebo‐treated groups were comparable in their clinical characteristics. Blood pressure did not change significantly in either group throughout the study. Urinary mean albumin excretion rate (MAER) decreased in the losartan‐treated group (p<0.01) whereas an increase was observed in the placebo group (p<0.05). At 6 months, the losartan‐treated group had significantly lower MAER than the placebo‐treated group [54.5 (58.3) vs 78.5 (100.5) µg/min, p<0.05; median (interquartile range)]. No significant differences were found in endothelium‐dependent or ‐independent vasodilation.ConclusionsType 2 diabetic patients with microalbuminuria have impaired endothelium‐dependent and ‐independent vasodilation. Treatment with low‐dose losartan is sufficient to reduce microalbuminuria in these patients without alteration in endothelial function and systemic blood pressure. Copyright © 2002 John Wiley & Sons, Ltd.
Serum IFN‐γ and IL‐10 levels are associated with disease progression in non‐obese diabetic mice
Authors: Schloot N. C. , Hanifi‐Moghaddam P. , Goebel C. , Shatavi S. V. , Flohé S. , Kolb H. , Rothe H. 
Published: August 2002

AbstractBackgroundThe goal of the present study was to determine whether cytokines in the peripheral blood of naive NOD mice correlate with the disease process and thereby would provide a marker for monitoring disease activity.MethodsFemale NOD mice (5, 10 and 14–16 weeks of age) were investigated in a cross‐sectional study. In the group of 14–16‐week‐old mice, non‐diabetic and diabetic mice were analysed as different subgroups. The Th1 cytokine (IFN‐γ) and the Th2 cytokine (IL‐10) were quantified in serum by sandwich enzyme‐linked immunosorbent assay (ELISA). Pancreatic mRNA for IFN‐γ and IL‐10 was determined by reverse transcriptase‐polymerase chain reaction (RT‐PCR) from the same animals.ResultsSerum levels of IFN‐γ were initially low but increased with age in NOD mice, reaching the highest levels at diabetes onset (p<0.002 compared to 10 weeks). A similar rise was noted in IFN‐γ gene expression in pancreatic lesions. In contrast, an early peak of serum IL‐10 levels was observed in non‐diabetic NOD mice (10 weeks) at a stage where non‐destructive insulitis occurs. With increasing age a continuous loss of IL‐10 until progression towards diabetes was observed. The pancreatic IL‐10 mRNA expression correlated with serum IL‐10 changes. As a consequence, the ratio of IFN‐γ/IL‐10, reflecting the Th1/Th2 balance in the serum, was significantly increased in diabetic compared to non‐diabetic NOD mice (p<0.005).ConclusionThese results demonstrate, for the first time, that an increased Th2 pattern in the non‐diabetic stage preceding a Th1 shift is associated with the development of diabetes in naive NOD mice. Serum cytokines correlate with disease progression and pancreatic cytokine expression during prediabetes. Soluble cytokines measured in the periphery are therefore promising surrogate markers of diabetes development. Copyright © 2002 John Wiley & Sons, Ltd.
Metformin decreases platelet superoxide anion production in diabetic patients
Authors: Gargiulo P. , Caccese D. , Pignatelli P. , Brufani C. , De Vito F. , Marino R. , Lauro R. , Violi F. , Di Mario U. , Sanguigni V. 
Published: August 2002

AbstractBackgroundPatients with type 2 diabetes mellitus are usually treated with oral antidiabetic agents but it is still not known whether these drugs have antioxidant effects in humans.MethodsWe studied 60 patients with type 2 diabetes mellitus, divided into three groups on the basis of hypoglycaemic treatment (Group A: metformin, Group B: glibenclamide, Group C: diet). All patients were followed for at least 1 year. The three subgroups had similar clinical characteristics. Twenty healthy subjects, of comparable sex and age, were enrolled as controls. In each subject, platelet production of superoxide anion (O2−) elicited by collagen, was determined by lucigenin assay.ResultsPatients with diabetes had higher platelet O2− production than controls; no correlation was observed between blood glucose and platelet O2− production. Group A patients had platelet O2− production similar to that of healthy subjects but lower than Group B and Group C patients.ConclusionThe present findings suggest an in vivo antioxidant activity of metformin and warrant prospective studies to further explore this hypothesis. Copyright © 2002 John Wiley & Sons, Ltd.