bluuebunny/crossref_metadata_2025_split huggingface dataset:
A gene necessary for normal male courtship, yellow, acts downstream of fruitless in the Drosophila melanogaster larval brain
Authors: Drapeau Mark David , Radovic Anna , Wittkopp Patricia J. , Long Anthony D. 
Published: March 2003

AbstractThe fruitless (fru) gene is a member of the Drosophila melanogaster somatic sex determination genetic pathway. Although it has been hypothesized that the primary function of fru is to regulate a genetic hierarchy specifying development of adult male courtship behavior, genes acting downstream of fru have not yet been identified. Here we demonstrate that the yellow (y) gene is genetically downstream of fru in the 3rd‐instar larval brain. Yellow protein is present at elevated levels in neuroblasts, which also show expression of male‐specific FRU proteins, compared to control neuroblasts without FRU. A location for y downstream of fru in a genetic pathway was experimentally demonstrated by analysis of fru mutants lacking transcription of zinc‐finger DNA binding domains, and of animals with temporal, spatial, or sexual mis‐expression of male‐specific FRU. A subset of fru and y mutants is known to reduce levels of a specific behavioral component of the male courtship ritual, wing extension, and FRU and Yellow were detected in the general region of the brain whose maleness is necessary for development of that behavior. We therefore hypothesized that ectopic expression of Yellow in the 3rd‐instar brain, in a y null background, would rescue low levels of wing extension and male competitive mating success, and this was found to be the case. Overall, these data suggest that y is a downstream member of the fru branch of the D. melanogaster sex determination hierarchy, where it plays a currently unknown role in the development of adult male wing extension during courtship. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 53–72, 2003
The expression of methyl CpG binding factor MeCP2 correlates with cellular differentiation in the developing rat brain and in cultured cells
Authors: Jung Benjamin P. , Jugloff Denis G.M. , Zhang Guangming , Logan Richard , Brown Stephanie , Eubanks James H. 
Published: March 2003

AbstractMutations in the MeCP2 gene cause Rett syndrome, a neurologic condition affecting primarily young girls. To gain insight into the normal function of MeCP2, we examined its temporal and spatial expression patterns, and immunoreactive prevalence, during late embryonic and perinatal brain development. MeCP2 mRNA was detected in most regions of the developing rat brain by the late embryonic stage. Regions displaying the strongest mRNA expression include the hippocampus, cortex, and cerebellum, and moderate expression was observed in most other brain regions. At the protein level, MeCP2 was strongly expressed in adult forebrain neurons, but was not detected in astrocytes. The nonubiquitous expression of MeCP2 was also observed in the embryonic cortex, as about one‐third of acutely dissociated embryonic day 14 neuroepithelial cells failed to stain with MeCP2. To test whether MeCP2 expression correlates with neuronal differentiation, colocalization of MeCP2 expression with either the precursor cell marker nestin or the young neuronal marker β‐III tubulin was examined in the same acutely dissociated cortical cells. Although strong MeCP2 expression was detected in approximately 75% of β‐III tubulin‐positive cells, only about 25% of nestin‐positive precursor cells were MeCP2 positive. Further support for a correlation of MeCP2 expression with cell differentiation was observed in culture, where Western blot analysis during the in vitro differentiation of PC12, NG108‐15, and SH‐SY5Y cells revealed that MeCP2 levels increased as the cells acquired a more differentiated phenotype. This increase was associated with differentiation, as MeCP2 expression levels did not vary within different phases of the cell cycle. Taken together, these data support a role for MeCP2 in the establishment and/or maintenance of neuronal maturity. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 86–96, 2003
The solvability conditions for inverse eigenproblem of symmetric and anti‐persymmetric matrices and its approximation
Authors: Xie Dongxiu , Hu Xiyan , Zhang Lei 
Published: March 2003

AbstractThe problem of generating a matrix A with specified eigen‐pair, where A is a symmetric and anti‐persymmetric matrix, is presented. An existence theorem is given and proved. A general expression of such a matrix is provided. We denote the set of such matrices by 𝒮𝒜𝒮En. The optimal approximation problem associated with 𝒮𝒜𝒮En is discussed, that is: to find the nearest matrix to a given matrix A* by A∈𝒮𝒜𝒮En. The existence and uniqueness of the optimal approximation problem is proved and the expression is provided for this nearest matrix. Copyright © 2002 John Wiley & Sons, Ltd.
Efficient approximation of the exponential operator for discrete 2D advection–diffusion problems
Authors: Bergamaschi Luca , Caliari Marco , Vianello Marco 
Published: March 2003

AbstractIn this paper we compare Krylov subspace methods with Faber series expansion for approximating the matrix exponential operator on large, sparse, non‐symmetric matrices. We consider in particular the case of Chebyshev series, corresponding to an initial estimate of the spectrum of the matrix by a suitable ellipse. Experimental results upon matrices with large size, arising from space discretization of 2D advection–diffusion problems, demonstrate that the Chebyshev method can be an effective alternative to Krylov techniques. Copyright © 2002 John Wiley & Sons, Ltd.
Moving least squares differential quadrature method and its application to the analysis of shear deformable plates
Authors: Liew K. M. , Huang Y. Q. , Reddy J. N. 
Published: March 2003

AbstractA moving least squares differential quadrature (MLSDQ) method is developed and employed for the analysis of moderately thick plates based on the first‐order shear deformation theory (FSDT). To carry out the analysis, the governing equations in terms of the generalized displacements (transverse deflection and two rotations) of the plate are formulated by employing the moving least squares approximation. The weighting coefficients used in the MLSDQ approximation are computed through a fast computation of shape functions and their derivatives. Numerical examples illustrating the accuracy, stability and convergence of the MLSDQ method are presented. Effects of support size, order of completeness and node irregularity on the numerical accuracy are investigated. Copyright © 2003 John Wiley & Sons, Ltd.
An analysis of strain localization in a shear layer under thermally coupled dynamic conditions. Part 2: Localized thermoplastic models
Authors: Armero F. , Park J. 
Published: March 2003

AbstractThe analyses presented in Part 1 of this work have shown the ill‐posedness of the governing equations for a shear layer governed by a coupled thermomechanical continuum model with strain softening. Finite element solutions of the problem have been shown to exhibit a pathological mesh‐size dependence in this case, as a consequence of the aforementioned ill‐posedness. The lack of a localized dissipative mechanism has been traced back to the origin of these difficulties. We consider in this paper the incorporation of such localized dissipative mechanism in the form of a cohesive law along a discontinuity of the displacements, the so‐called strong discontinuity. A coupled thermomechanical model of these discontinuities is formulated involving a continuous temperature field. The discontinuity of the heat flow (i.e. the derivative of the temperature) accommodates the presence of the localized dissipation associated to the thermomechanical cohesive law. In this context, we obtain the exact solution of a problem of wave propagation in the shear layer when the response of the bulk of the layer is elastic. The physical nature of the solution, in contrast with the solutions obtained in Part 1 for continuum models, illustrates the regularizing effect of these localized models, showing in particular the continuous dependence of the solution on the material parameters. Furthermore, we obtain the exact solution of the problem involving a regularized discontinuity in a domain of finite length. This analysis allows to gain a full understanding of the properties of finite element approximations of the problem. Several numerical simulations are presented in this context corroborating the conclusions drawn from the analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Rigid–plastic interface for an embedded crack
Authors: Spencer B. W. , Shing P. B. 
Published: March 2003

AbstractDiscrete cracks have traditionally been modelled by zero‐thickness interface elements. Such models usually assume that the relative displacements across the interface have both elastic and inelastic components. In such a case, the elastic stiffness assigned to the interface acts as a penalty parameter that must be high enough to ensure that the elastic deformations will be minimal. In recent years, solid finite‐elements with embedded displacement discontinuities have emerged as an alternative way to model discrete cracks. A method that allows for an embedded crack element to use any plasticity‐based constitutive model for the internal interface, but without penalty parameters, is presented in this paper. In this method, the elastic properties of the solid portion of the element are used to perform the function that the penalty parameters previously have been used to perform. The resulting interface model is perfectly rigid–plastic. Numerical comparisons show significant improvements in accuracy and efficiency over the penalty method. Copyright © 2003 John Wiley & Sons, Ltd.
Geometrically non‐linear anisotropic inelasticity based on fictitious configurations: Application to the coupling of continuum damage and multiplicative elasto‐plasticity
Authors: Menzel A. , Steinmann P. 
Published: March 2003

AbstractThe objective of this contribution is the formulation and algorithmic treatment of a phenomenological framework to capture anisotropic, geometrically non‐linear inelasticity.In addition to the intermediate configuration of multiplicative elasto‐plasticity, we further introduce two microscopic configurations of Lagrangian and Eulerian type which characterize the so‐called fictitious undamaged material. This kinematical framework enables us to apply two well‐established postulates based on standard terminology in non‐linear continuum mechanics. Concerning the free energy function, the postulate of strain energy equivalence is adopted and in view of the plastic dissipation potential the concept of effective stress is a natural outcome of the underlying kinematical assumptions.Finally, we focus on the integration technique for the class of obtained evolution equations and present numerical examples for a prototype model to underline the applicability of the proposed framework. Copyright © 2003 John Wiley & Sons, Ltd.
Scaling up CBOs for second‐order devolution in welfare reform
Authors: Poole Dennis L. 
Published: March 2003

AbstractThe Personal Responsibility and Work Opportunity Act of 1996 created a paradigm shift in the financing,
organization, and delivery of welfare programs in the United States. The act shifted revenue and authority to
states, giving them great discretion to determine the specifics of their programs. First‐order devolution,
combined with time limits and work requirements, set in motion a chain of events that moved Temporary Assistance
to Needy Families (TANF) recipients into the labor force and off state welfare rolls.
Second‐order devolution shifted revenue and authority to community‐based organizations
(CBOs) to help former recipients remain employed, advance to higher paying jobs, and move their families
toward economic self‐sufficiency. Early findings from project innovations in Texas and other states raise
doubts about the capacity of these organizations to achieve these goals. State funders will need to provide
ongoing technical assistance and support to “scale up” the capacity of CBOs to plan, implement, and
manage local innovations in welfare reform.
Nonstandard discretizations of the generalized Nagumo reaction‐diffusion equation
Authors: Chen Z. , Gumel A. B. , Mickens R. E. 
Published: March 2003

AbstractA competitive nonstandard semi‐explicit finite‐difference method is constructed and used to obtain numerical solutions of the diffusion‐free generalized Nagumo equation. Qualitative stability analysis and numerical simulations show that this scheme is more robust in comparison to some standard explicit methods such as forward Euler and the fourth‐order Runge‐Kutta method (RK4). The nonstandard scheme is extended to construct a semi‐explicit and an implicit scheme to solve the full Nagumo reaction‐diffusion equation. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 363–379, 2003.
Single‐cell discretization of O(kh2 + h4) for ∂u/∂n for three‐space dimensional mildly quasi‐linear parabolic equation
Authors: Mohanty R. K. , Kumar Dinesh , Jain M. K. 
Published: March 2003

AbstractIn this article, using a single computational cell, we report some stable two‐level explicit finite difference approximations of O(kh2 + h4) for ∂u/∂n for three‐space dimensional quasi‐linear parabolic equation, where h > 0 and k > 0 are mesh sizes in space and time directions, respectively. When grid lines are parallel to x‐, y‐, and z‐coordinate axes, then ∂u/∂n at an internal grid point becomes ∂u/∂x, ∂u/∂y, and ∂u/∂z, respectively. The proposed methods are also applicable to the polar coordinates problems. The proposed methods have the simplicity in nature and use the same marching type of technique of solution. Stability analysis of a linear difference equation and computational efficiency of the methods are discussed. The results of numerical experiments are compared with exact solutions. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 327–342, 2003.
Obstacles to desegregating public housing: Lessons learned from implementing eight consent decrees
Authors: Popkin Susan J. , Galster George C. , Temkin Kenneth , Herbig Carla , Levy Diane K. , Richer Elise K. 
Published: March 2003

AbstractBetween 1992 and 1996 the U.S. Department of Housing and Urban Development (HUD) settled a number of legal cases involving housing authorities and agreed to take remedial action as part of court‐enforced consent decrees entered into with plaintiffs. These housing authorities faced significant obstacles that impaired their ability to comply swiftly and fully with all of the elements in the desegregation consent decrees. The obstacles fell into two broad categories: contextual obstacles (racial composition of waiting lists and resident populations, lack of affordable rental housing, and inadequate public transportation), and capacity and coordination obstacles (conflict among implementing agencies and ineffective monitoring by HUD). Findings presented here highlight the sizable potential delay between the time a legal remedy is imposed and when plaintiffs in public housing segregation disputes realize any benefits. They also reinforce the argument that implementation problems will be legion when policies impose a significant scope of required changes on a large number of actors who must collaborate, yet are not uniformly capable or sympathetic to the goals being promoted. © 2003 by the Association for Public Policy Analysis and Management.
Progressive genomic alterations in intraductal papillary mucinous tumours of the pancreas and morphologically similar lesions of the pancreatic ducts
Authors: Soldini Davide , Gugger Matthias , Burckhardt Elisabeth , Kappeler Andreas , Laissue Jean A , Mazzucchelli Luca 
Published: March 2003

AbstractIntraductal papillary mucinous tumours (IPMTs) of the pancreas are rare neoplasms characterized by a prominent intraductal component, and by malignant potential. Little data exists concerning numerical chromosome aberrations in IPMTs. The biological significance of mucinous epithelial changes (mucinous hyperplasia) in small branching ducts adjacent to IPMTs also remains unclear. From a series of 12 IPMTs, we investigated by interphase cytogenetics 22 foci with mucinous hyperplasia, 27 foci with borderline lesions, and 11 samples with either intraductal (CIS) or invasive carcinoma. Chromosome 6 loss was detected in areas with mucinous hyperplasia (36.3%), borderline lesions (96.3%), and CIS/invasive carcinoma (100%). Similar losses, indicating clonal progression, were found for chromosome 17 (18.2%, 81.5%, and 100%), and for chromosome 18 (0%, 18.5%, and 100%). Quantitative analysis showed a significant intraductal expansion of cell clones harbouring these numerical aberrations within the spectrum of IPMTs. Mucinous epithelial changes in 11 resection samples with chronic pancreatitis showed monosomy 6 (36%) and monosomy 17 (27%). Conversely, areas with low‐grade pancreatic intraepithelial neoplasia (PanIN‐1), obtained from eight surgical specimens with ductal adenocarcinoma, showed monosomies for chromosome 6, 17, and 18 (100%, 87%, and 50%, respectively). We conclude that monosomies, as defined by FISH analysis, are frequent in both IPMTs and mucinous hyperplasia of pancreatic ducts adjacent to IPMTs. Monosomy 6 may represent an early event in the stepwise accumulation of genomic mutations necessary for the neoplastic transformation of pancreatic duct epithelia, whereas loss of chromosome 18 may be implicated in the progression of borderline to malignant IPMT. The detection of complex chromosomal aberrations in mucinous epithelial changes, and the quantitative expansion of monosomic cell clones in pancreatic ducts, provide evidence for a continuum between hyperplastic and dysplastic epithelial changes. Copyright © 2003 John Wiley & Sons, Ltd.
Different expression patterns of calpain isozymes 1 and 2 (CAPN1 and 2) in squamous cell carcinomas (SCC) and basal cell carcinomas (BCC) of human skin
Authors: Reichrath Jörg , Welter Cornelius , Mitschele Tanja , Classen Ulf , Meineke Viktor , Tilgen Wolfgang , Seifert Markus 
Published: March 2003

AbstractCalpain, also named CAPN (for calcium‐activated neutral protease), is a ubiquitous intracellular cytoplasmic non‐lysosomal cysteine endopeptidase that requires calcium ions to exert its activity. Two major isoenzymes are known—µ‐calpain (CAPN1) and m‐calpain (CAPN2)—requiring micromolar and millimolar calcium concentrations for activation, respectively. Many known substrates of the different calpain isoenzymes, such as the transcription factors c‐Fos and c‐Jun, the tumour suppressor protein p53, protein kinase C, pp60src, or the adhesion molecule integrin, have been implicated in the pathogenesis of various malignancies including squamous (SCC) and basal (BCC) cell carcinomas of human skin, suggesting an important role of the calpain isoenzymes in malignant diseases. We have analysed the expression of CAP1 and CAPN2 protein and mRNA expression in BCCs and SCCs of human skin. Interestingly, CAPN1 immunoreactivity (streptavidin–peroxidase technique) was markedly reduced in BCCs compared to normal human skin or SCCs, while in contrast CAPN1 mRNA levels (determined by real‐time PCR) were markedly elevated in BCCs and SCCs compared to normal human skin. No differences were found analysing CAPN2 protein and mRNA expression in normal human skin, BCCs and SCCs. In conclusion, we have demonstrated for the first time alterations in calpain mRNA expression and protein content in malignant skin tumours that may be of importance for the tumorigenesis and growth characteristics of BCCs and SCCs. However, our results do not allow conclusions on the function of CAPN1 and CAPN2 in BCCs and SCCs. It is not known if the CAPN genes in BCCs or SCCs exhibit functionally inactivating mutations or whether decreased CAPN1 protein expression in BCCs and elevated CAPN1 mRNA in BCCs and SCCs reflect a feedback loop coupled with increased degradation or proteolysis of CAPN1 protein. Copyright © 2003 John Wiley & Sons, Ltd.
Proteoglycans and WT1 as markers for distinguishing adenocarcinoma, epithelioid mesothelioma, and benign mesothelium
Authors: Gulyás Miklós , Hjerpe Anders 
Published: March 2003

AbstractMalignant mesothelioma is a tumour frequently accompanied by an effusion with elevated hyaluronan levels. To distinguish malignant mesothelioma, adenocarcinoma, and reactive benign mesothelium with cytological and histological methods including immunocytochemistry is a major diagnostic challenge. The Wilms' tumour susceptibility gene 1 (WT1), expressed during transition of mesenchyme to epithelial tissues, is regarded as a marker for the mesothelial lineage. Its effect on the cell phenotype may be regulated via the syndecans, i.e. proteoglycans on the cell surface. To determine how WT1, proteoglycans, and hyaluronan synthase are expressed in mesothelioma, adenocarcinoma, and reactive benign mesothelium, we studied these molecules at the mRNA and protein levels, with the additional purpose of finding diagnostic parameters. Adenocarcinoma cells produced more mRNA for syndecan‐1, but cells derived from mesothelium expressed WT1, biglycan, and larger amounts of syndecan‐2. The difference in gene expression of these two syndecans was best monitored by the ratio between them. Syndecan‐4 was highly expressed in all malignant cell lines, this expression being 1.7–5 times greater than in benign mesothelial cells. Although hyaluronan synthase‐1 and versican could not distinguish between the three conditions, versican expression was associated with a high rate of proliferation. These findings suggest that syndecan‐1 and syndecan‐2 together may be useful diagnostic markers, with stronger staining for the latter epitope in mesothelial tissues. The alternating appearance of these two syndecans can be shown not only by RT‐PCR and FACS in vitro, but also by immunohistochemistry on clinical material. Copyright © 2003 John Wiley & Sons, Ltd.
Correlation between immunohistochemistry (HercepTest) and fluorescence in situ hybridization (FISH) for HER‐2 in 426 breast carcinomas from 37 centres
Authors: Dowsett M , Bartlett J , Ellis IO , Salter J , Hills M , Mallon E , Watters AD , Cooke T , Paish C , Wencyk PM , Pinder SE 
Published: March 2003

AbstractAccurate diagnostic assessment of HER‐2 is essential for the appropriate application of the humanized anti‐HER‐2 monoclonal antibody trastuzumab (Herceptin) to the treatment of patients with metastatic breast cancer. The diagnostic test needs to be applicable to archival, fixed tissue removed at excision, in many cases several years earlier. We compared the assessment of HER‐2 by immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridization (FISH) in 426 breast carcinomas from patients being considered for trastuzumab therapy. The tumours were tested in three reference centres having been sent in from 37 hospitals. Only 2/270 (0.7%) IHC 0/1+ tumours were FISH positive. Six of 102 (5.9%) IHC 3+ tumours were FISH negative. Five of the six had between 1.75 and 2.0 HER‐2 gene copies per chromosome 17 and the sixth had multiple copies of chromosome 17. Thirteen per cent of tumours were IHC 2+ and overall 48% of these were FISH positive but this proportion varied markedly between the centres. Sixty IHC‐stained slides selected to be enriched with 2+ cases were circulated between the three laboratories and scored. There were 20 cases in which there was some discordance in scoring. Consideration of the FISH score in these cases led to concordance in the designation of positivity/negativity in 19 of these 20 cases. These data support an algorithm in which FISH testing is restricted to IHC 2+ tumours in reference centres. The results may not extrapolate to laboratories with less experience or using different methodologies. Copyright © 2003 John Wiley & Sons, Ltd.