bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial representation of odorant structure in the moth antennal lobe: A study of structure–response relationships at low doses
Authors: Meijerink Jocelijn , Carlsson Mikael A. , Hansson Bill S. 
Published: October 2003

AbstractHow odorant structure and concentration are spatially represented within the primary olfactory integration center, the antennal lobe (AL) or olfactory bulb (OB) in invertebrates and vertebrates, respectively, is currently a topic of high interest. Here, we show the spatial representation of odorant structure in the antennal lobe of the moth Spodoptera littoralis by imaging calcium activity evoked by straight chain aliphatic alcohols and aldehydes at low doses. Activity patterns of a given odor were most similar to compounds with the same functional group, differing in chain length by only one carbon atom. A chain length dependency was present as the most activated glomerulus in the lobe shifted from a medial to a lateral position with increasing chain length of the molecule. Statistical analysis revealed that in both classes of chemicals the chain length of the molecule was represented in a similar way. No topographically fixed domains were observed for any of the classes. However, activity patterns evoked by lower chain length molecules were spatially more distinct than patterns evoked by higher chain length molecules. The number of activated glomeruli for both classes of chemicals increased with increasing chain length to reach a maximum at eight or nine C atoms followed by a decrease as the chain length further increased. J. Comp. Neurol. 467:11–21, 2003. © 2003 Wiley‐Liss, Inc.
Expression of constitutively active p21H‐rasval12 in postmitotic pyramidal neurons results in increased dendritic size and complexity
Authors: Alpár Alán , Palm Kirstin , Schierwagen Andreas , Arendt Thomas , Gärtner Ulrich 
Published: October 2003

AbstractThe small G protein p21Ras is a critical molecular switch for relaying neurotrophic actions and is essential for normal functioning and plasticity of the nervous system. In this study, the morphogenetic effects of p21Ras were investigated on neurons in vivo. Morphological changes of layers II/III and Vb commissural pyramidal neurons of the primary somatosensory cortex were analyzed in transgenic mice expressing permanently active p21H‐RasVal12 in postmitotic neurons. Pyramidal cells were retrogradely labelled with biotinylated dextran amine and subsequently traced using Neurolucida. Compared with wild‐type mice, transgenic animals showed a significant increase in the surface area and volume of basal dendrites on the proximal and intermediate segments in layers II/III and on further distal segments in layer V. In addition, the surface area and volume of the trunk and of the proximal segments of oblique branches of apical dendrites were enlarged in both layers. Sholl analyses of basal and apical dendrites showed a significant increase in dendritic complexity of layer V neurons. A positive correlation was observed between the size of the basal dendrite and the neuronal soma size in the transgenic population, indicating that growth‐promoting effects of p21H‐RasVal12 affect both cellular compartments in parallel. However, the dendritic surface correlated with the number of tips and dendritic stem diameter in both wild‐type and transgenic populations, demonstrating that these relations represent rather conservative design principles in dendritic morphology. The data presented here suggest an important role of p21Ras‐dependent signaling in the final differentiation and maintenance of dendritic morphology. J. Comp. Neurol. 467:119–133, 2003. © 2003 Wiley‐Liss, Inc.
Coupling of mapped wave infinite elements and plane wave basis finite elements for the Helmholtz equation in exterior domains
Authors: Sugimoto Rie , Bettess Peter 
Published: October 2003

AbstractThe theory for coupling of mapped wave infinite elements and special wave finite elements for the solution of the Helmholtz equation in unbounded domains is presented. Mapped wave infinite elements can be applied to boundaries of arbitrary shape for exterior wave problems without truncation of the domain. Special wave finite elements allow an element to contain many wavelengths rather than having many finite elements per wavelength like conventional finite elements. Both types of elements include trigonometric functions to describe wave behaviour in their shape functions. However the wave directions between nodes on the finite element/infinite element interface can be incompatible. This is because the directions are normally globally constant within a special finite element but are usually radial from the ‘pole’ within a mapped wave infinite element. Therefore forcing the waves associated with nodes on the interface to be strictly radial is necessary to eliminate this internode incompatibility. The coupling of these elements was tested for a Hankel source problem and plane wave scattering by a cylinder and good accuracy was achieved. This paper deals with unconjugated infinite elements and is restricted to two‐dimensional problems. Copyright © 2003 John Wiley & Sons, Ltd.
Interior point optimization and limit analysis: an application
Authors: Pastor Joseph , Thai The‐Hung , Francescato Pascal 
Published: October 2003

AbstractThe well‐known problem of the height limit of a Tresca or von Mises vertical slope of height h, subjected to the action of gravity stems naturally from Limit Analysis theory under the plane strain condition. Although the exact solution to this problem remains unknown, this paper aims to give new precise bounds using both the static and kinematic approaches and an Interior Point optimizer code. The constituent material is a homogeneous isotropic soil of weight per unit volume γ. It obeys the Tresca or von Mises criterion characterized by C cohesion. We show that the loading parameter to be optimized, γh/C, is found to be between 3.767 and 3.782, and finally, using a recent result of Lyamin and Sloan (Int. J. Numer. Meth. Engng. 2002; 55: 573), between 3.772 and 3.782. The proposed methods, combined with an Interior Point optimization code, prove that linearizing the problem remains efficient, and both rigorous and global: this point is the main objective of the present paper. Copyright © 2003 John Wiley & Sons, Ltd.
A novel approach to the convexity control of interpolant curves
Authors: Duan Qi , Wang Liqiu , Twizell E. H. 
Published: October 2003

AbstractA method is presented for controlling the convexity of interpolant curves based on a rational cubic interpolating function with quadratic denominator. The key idea is that the uniqueness of the interpolating function for the given data is replaced by the uniqueness of the interpolating function for the given data and the parameters, so that for the given data the shape of the interpolating curve can be modified by selecting suitable parameters. Necessary and sufficient conditions are given for adjusting the convexity of the interpolating curve for given data. Examples are given and the optimal error estimation is given. Copyright © 2003 John Wiley & Sons, Ltd.
Thermal avalanche for blowup solutions of semilinear heat equations
Authors: Quirós Fernando , Rossi Julio D. , Vázquez Juan Luis 
Published: October 2003

AbstractWe consider the semilinear heat equation ut = Δu + up both in ℝN and in a bounded domain with homogeneous Dirichlet boundary conditions, with 1 < p < ps where ps is the Sobolev exponent. This problem has solutions with finite‐time blowup; that is, for large enough initial data there exists T < ∞ such that u is a classical solution for 0 < t < T, while it becomes unbounded as t ↗ T. In order to understand the situation for t > T, we consider a natural approximation by reaction problems with global solution and pass to the limit. As is well‐known, the limit solution undergoes complete blowup: after it blows up at t = T, the continuation is identically infinite for all t > T.We perform here a deeper analysis of how complete blowup occurs. Actually, the singularity set of a solution that blows up as t ↗ T propagates instantaneously at time t = T to cover the whole space, producing a catastrophic discontinuity between t = T− and t = T+. This is called the “avalanche.” We describe its formation as a layer appearing in the limit of the natural approximate problems. After a suitable scaling, the initial structure of the layer is given by the solution of a limit problem, described by a simple ordinary differential equation. As t proceeds past T, the solutions of the approximate problems have a traveling wave behavior with a speed that we compute. The situation in the inner region depends on the type of approximation: a conical pattern is formed with time when we approximate the power up by a flat truncation at level n, while for tangent truncations we get an exponential increase in time and a diffusive spatial pattern. © 2003 Wiley Periodicals, Inc.
Local minimizers with vortices to the Ginzburg‐Landau system in three dimensions
Authors: Montero J. Alberto , Sternberg Peter , Ziemer William P. 
Published: October 2003

AbstractWe construct local minimizers to the Ginzburg‐Landau energy in certain three‐dimensional domains based on the asymptotic connection between the energy and the total length of vortices using the theory of weak Jacobians. Whenever there exists a collection of locally minimal line segments spanning the domain, we can find local minimizers with arbitrarily assigned degrees with respect to each segment. © 2003 Wiley Periodicals, Inc.
Pseudoholomorphic strips in symplectizations II: Fredholm theory and transversality
Authors: Abbas Casim 
Published: October 2003

AbstractThis paper is part of a larger program, the investigation of the chord problem in three dimensional contact geometry. The main tool will be pseudoholomorphic strips in the symplectisation of a three dimensional contact manifold with two totally real submanifolds L0, L1 as boundary conditions. The submanifolds L0 and L1 do not intersect transversally. In this paper we will develop a nonlinear Fredholm theory that guarantees the existence of a family of embedded pseudoholomorphic strips near a given one with suitable properties. © 2003 Wiley Periodicals, Inc.
A set‐oriented method definition language for object databases and its semantics
Authors: Bertino Elisa , Guerrini Giovanna , Merlo Isabella 
Published: October 2003

AbstractIn this paper we propose a set‐oriented rule‐based method definition language for object‐oriented databases. Most existing object‐oriented database systems exploit a general‐purpose imperative object‐oriented programming language as the method definition language. Because methods are written in a general‐purpose imperative language, it is difficult to analyze their properties and to optimize them. Optimization is important when dealing with a large amount of objects as in databases. We therefore believe that the use of anad hoc, set‐oriented language can offer some advantages, at least at the specification level. In particular, such a language can offer an appropriate framework to reason about method properties.In this paper, besides defining a set‐oriented rule‐based language for method definition, we formally define its semantics, addressing the problems of inconsistency and non‐determinism in set‐oriented updates. Moreover, we characterize some relevant properties of methods, such as conflicts among method specifications in sibling classes and behavioral refinement in subclasses. Copyright © 2003 John Wiley & Sons, Ltd.
Zebrafish pronephros: A model for understanding cystic kidney disease
Authors: Hostetter Christine L. , Sullivan‐Brown Jessica L. , Burdine Rebecca D. 
Published: October 2003

AbstractThe embryonic kidney of the zebrafish is the pronephros. The ease of genetic analysis and experimentation in zebrafish, coupled with the simplicity of the pronephros, make the zebrafish an ideal model system for studying kidney development and function. Several mutations have been isolated in zebrafish genetic screens that result in cyst formation in the pronephros. Cloning and characterization of these mutations will provide insight into kidney development but may also provide understanding of the molecular basis of cystic kidney diseases. In this review, we focus on the zebrafish as a model for understanding cystic kidney disease and the links between cystic kidney disease and left–right patterning. Developmental Dynamics, 2003. © 2003 Wiley‐Liss, Inc.
Current progress in neural crest cell motility and migration and future prospects for the zebrafish model system
Authors: Halloran Mary C. , Berndt Jason D. 
Published: October 2003

AbstractThe neural crest is a unique population of cells that contributes to the formation of diverse cell types, including craniofacial cartilage, peripheral neurons, the cardiac outflow tract, and pigment cells. Neural crest cells (NCCs) are specified within the neuroepithelium, undergo an epithelial‐to‐mesenchymal transition, and migrate to target destinations throughout the embryo. Here, we review current understanding of two steps in NCC development, both of which involve NCC motility. The first is NCC delamination from the neuroepithelium and the changes in cell adhesion and the cytoskeleton necessary for the initiation of migration. The second is NCC migration and the signals that guide NCCs along specific migratory pathways. We illustrate the strength of the zebrafish, Danio rerio, as a model organism to study NCC motility. The zebrafish is particularly well suited for the study of neural crest motility because of the ability to combine genetic manipulation with live imaging of migrating NCCs. Developmental Dynamics, 2003. © 2003 Wiley‐Liss, Inc.
Differential expression of Na,K‐ATPase α and β subunit genes in the developing zebrafish inner ear
Authors: Blasiole Brian , Degrave Agnes , Canfield Victor , Boehmler Wendy , Thisse Christine , Thisse Bernard , Mohideen Manzoor‐Ali P.K. , Levenson Robert 
Published: October 2003

AbstractWe have used whole‐mount in situ hybridization to analyze Na,K‐ATPase α and β subunit gene expression in the developing zebrafish ear. Four α1‐like (α1a.1, α1a.2, α1a.4, and α1a.5) and two β (β1a and β2b) subunit genes are expressed in ear beginning at mid‐somitogenesis. Each gene exhibits a distinct spatial and temporal expression pattern. The α1a.1 gene was ubiquitously expressed in the otic epithelium from mid‐somitogenesis to 24 hr postfertilization (hpf). Expression of this gene was gradually reduced and by 48 hpf, α1a.1 transcripts were no longer detectable in the ear. The α1a.2 and α1a.5 genes were expressed in regions that correspond to the anterior macula, lateral crista, and semicircular canal projections up to 48 hpf. At later stages, expression of these genes was limited to cells in the dorsolateral septum and semicircular canal projections. α1a.4 and β1a transcripts were ubiquitously expressed during ear development and were present in most otic tissues at 5 days postfertilization (dpf). Expression of the β2b gene, on the other hand, was restricted to subsets of cells that form sensory epithelia. These results strongly suggest different functional roles for individual Na,K‐ATPase genes in zebrafish ear development. Na,K‐ATPase genes are likely to represent useful markers for the analysis of zebrafish otogenesis. Development Dynamics, 2003. © 2003 Wiley‐Liss, Inc.
p38 MAPK is a critical regulator of the constitutive and the β4 integrin‐regulated expression of IL‐6 in human normal thymic epithelial cells
Authors: Mainiero Fabrizio , Colombara Michaela , Antonini Valeria , Strippoli Raffaele , Merola Marcello , Poffe Ornella , Tridente Giuseppe , Ramarli Dunia 
Published: October 2003

AbstractCytokines and adhesion receptors are key mediators in the dialog occurring between thymic epithelial cells (TEC) and thymocytes and regulating T cell maturation and epithelial embryonic differentiation. Among cytokines, IL‐6 can be critical in the thymus, fostering proliferation, differentiation and/or survival of both TEC and thymocytes. We have previously reported in human normal TEC that clustering of the laminin receptor α6β4 integrin induced by thymocyte contact or monoclonal antibody‐mediated cross‐linking regulates IL‐6 gene expression via activation of NF‐κB and NF‐IL6 transactivators. Here we show that α6β4 integrin activates p38 mitogen‐activated protein kinase (MAPK) and that p38 is essential for IL‐6 gene expression. In fact, β4 cross‐linking activated p38 and extracellular signal‐regulated kinase (ERK) MAPK, Rac1, p21‐activated protein kinase 1 (PAK1) and MAPK kinases (MKK) 3/MKK6. However, pharmacological blockade of p38 or ERK demonstrated that p38 inhibition abrogated both basal and β4 integrin‐induced production of IL‐6 preventing NF‐κB and NF‐IL6 activation, whereas ERK inhibition reduced IL‐6 production, hampering only NF‐κB activation. Overall, our results indicate that p38 MAPK and α6β4 integrin, expressed by TEC throughout their life, are critical regulators of the intrathymic availability of a cytokine controlling fate and functions of cells governing development and maintenance of thymic architecture and immune responses.
Treponemal glycoconjugate inhibits Toll‐like receptor ligand‐induced cell activation by blocking LPS‐binding protein and CD14 functions
Authors: Asai Yasuyuki , Hashimoto Masahito , Ogawa Tomohiko 
Published: October 2003

AbstractSpirochetes are well‐known as causative agents of various chronic infectious diseases. Glycolipids of small‐sized Treponema spirochetes have been shown to exhibit immunostimulating activities. In this study, we found that a glycoconjugate preparation obtained from Treponema medium (Tm‐Gp), an intermediate‐sized oral Treponema seen in subgingival plaque from patients with chronic periodontal diseases, diminished the LPS‐induced activation of a human monocytic cell line, while TNF‐α‐induced activation was unaffected. NF‐κB activation in Ba/F3 cells expressing murine Toll‐like receptor (TLR) 4 and MD‐2 was inhibited by Tm‐Gp in a CD14/LPS‐binding protein (LBP)‐dependent manner when stimulated with LPS or its active center lipid A but not whenstimulated with Taxol. Tm‐Gp blocked the binding of LPS to immobilized CD14 and LBP and inhibited nitric oxide (NO) production by a murine Mϕ cell line following stimulation with peptidoglycan and LPS in the presence of FBS, while NO production in response poly (I:C) RNA or CpG DNA remained unaffected. The inhibitory effects of Tm‐Gp seem to be attributable to the lipophilic portion of the glycoconjugate. These results indicate that T. medium contains a glycoconjugate possessing an inhibitory effect on TLR‐mediated cell activation through interaction with LBP and CD14.
The Toll‐like receptor 7 (TLR7)‐specific stimulus loxoribine uncovers a strong relationship within the TLR7, 8 and 9 subfamily
Authors: Heil Florian , Ahmad‐Nejad Parviz , Hemmi Hiroaki , Hochrein Hubertus , Ampenberger Franziska , Gellert Tanja , Dietrich Harald , Lipford Grayson , Takeda Kiyoshi , Akira Shizuo , Wagner Hermann , Bauer Stefan 
Published: October 2003

AbstractLoxoribine (7‐allyl‐7,8‐dihydro‐8‐oxo‐guanosine) acts as synthetic adjuvant in anti‐tumor responses. Here we first demonstrate that loxoribine activates cells of the innate immune system selectively via the Toll‐like receptor (TLR) 7/MyD88‐dependent signaling pathway. TLR7‐ and MyD88‐deficient immune cells fail to proliferate or produce cytokines in response to loxoribine, and genetic complementation of TLR7‐deficient cells with murine or human TLR7 confers responsiveness. Subsequently we show that cellular activation by loxoribine and resiquimod (R‐848), a stimulus for TLR7 and TLR8, depends on acidification and maturation of endosomes and targets MyD88 to vesicular structures with lysosomal characteristics. This mode of TLR7 and TLR8 action resembles CpG‐DNA‐driven TLR9 activation. We thus conclude that TLR7, 8 and 9 form a functional subgroup within the TLR family that recognizes pathogen‐associated molecular patterns in endosomal/lysosomal compartments.
Anti‐tumor immune responses and tumor regression induced with mimotopes of a tumor‐associated T cell epitope
Authors: Tumenjargal Sherev , Gellrich Sylke , Linnemann Thomas , Muche J. Marcus , Lukowsky Ansgar , Audring Heike , Wiesmüller Karl‐Heinz , Sterry Wolfram , Walden Peter 
Published: October 2003

AbstractMimotopes provide an alternative to natural T cell epitopes for cancer immune therapy, as they can recruit and stimulate T cell repertoires that deviate from the repertoires engaged with the tumor and exposed to disease‐related immune suppression. Here, mimotopes of a shared tumor‐associated T cell epitope in cutaneous lymphoma were tested for their capacities to induce clinical and immunological responses in cancer patients. The mimotope sequences had been determined by a combinatorial peptide library approach without knowledge of the corresponding natural tumor‐associated antigen. Vaccination with these mimotopes together with helper T cell‐inducing antigens led to complete tumor remission in the two patients tested. After each booster vaccination, enhanced frequencies of mimotope‐specific CD8+ T cells were detected in the peripheral blood of the patients, and the CTL proved to be cytotoxic and tumoricidal when tested in vitro. These data provide a first indication of clinical efficacy of mimotopes in cancer patients.
Human dendritic cells respond to Porphyromonas gingivalis LPS by promoting a Th2 effector response in vitro
Authors: Jotwani Ravi , Pulendran Bali , Agrawal Sudhanshu , Cutler Christopher W. 
Published: October 2003

AbstractUnderstanding how mucosal pathogens modulate the immune response may facilitate the development of vaccines for disparate human diseases. In the present study, human monocyte‐derived DC (MDDC)were pulsed with LPS of the oral pathogen Porphyromonas gingivalis and Escherichia coli 25922 and analyzed for: (i) production of Th‐biasing/inflammatory cytokines; (ii) maturation/costimulatory molecules; and (iii) induction of allogeneic CD4+ and naive CD45RA+ T cell proliferation and release of Th1 or Th2 cytokines. We show that E. coli LPS‐pulsed MDDC released Th1‐biasing cytokines — consisting of high levels of IL‐12 p70, IFN‐γ‐inducible protein 10 (IP‐10) – but also TNF‐α, IL‐10, IL‐6 and IL‐1β. In contrast, no IL‐12 p70 or IP‐10, and lower levels of TNF‐α and IL‐10 were induced by P. gingivalis LPS. These differences were sustained at LPS doses that yielded nearly equivalent maturation of MDDC; moreover the T cell response was consistent: E. coli LPS‐pulsed MDDC induced higher T cell proliferation, and T cells released more IFN‐γ and IL‐2, but less IL‐5 than T cells co‐cultured with P. gingivalis LPS pulsed‐MDDC. IL‐13 was secreted by naive CD45RA+CD45RO–CD4+ T cells in response to P. gingivalisLPS‐pulsed MDDC. These results suggest that human MDDC can be polarized by LPS from the mucosal pathogen P. gingivalis to induce a Th2 effector response in vitro.
Mesh deformation and modification for time dependent problems
Authors: Baker Timothy J. 
Published: October 2003

AbstractMesh coarsening and mesh refinement are combined to provide a flexible approach for the adaptation of time dependent problems. When the shape of the domain remains fixed but the computed solution is unsteady (e.g. vortex shedding of laminar flow over a cylinder), successive applications of coarsening and refinement allow the computed solution to be tracked in an efficient manner. The addition of a mesh movement phase extends this technique to handle a domain whose shape is also evolving with time. Copyright © 2003 John Wiley & Sons, Ltd.