bluuebunny/crossref_metadata_2025 huggingface dataset:
A set‐oriented method definition language for object databases and its semantics
Authors: Bertino Elisa , Guerrini Giovanna , Merlo Isabella
Published: October 2003

In 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

The 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

The 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

We 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

Cytokines 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

Spirochetes 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

Loxoribine (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

Mimotopes 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

Understanding 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

Mesh 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.
Computational modelling of 1D blood flow with variable mechanical properties and its application to the simulation of wave propagation in the human arterial system
Authors: Sherwin S. J. , Formaggia L. , Peiró J. , Franke V.
Published: October 2003

In this paper we numerically investigate a one‐dimensional model of blood flow in human arteries using both a discontinuous Galerkin and a Taylor–Galerkin formulation. The derivation of the model and the numerical schemes are detailed and applied to two model numerical experiments. We first study the effect of an intervention, such the implantation of a vascular prosthesis (e.g. a stent), which leads to an abrupt variation of the mechanical characteristics of an artery. We then discuss the simulation of the propagation of pressure and velocity waveforms in the human arterial tree using a simplified model consisting of the 55 main arteries. Copyright © 2003 John Wiley & Sons, Ltd.
Transient fixed point‐based unstructured mesh adaptation
Authors: Alauzet F. , George P. L. , Mohammadi B. , Frey P. , Borouchaki H.
Published: October 2003

This paper deals with adaptive simulation of time‐dependent problems. Mesh adaptation for unsteady configurations is especially important as the phenomenon evolves in the whole computational domain and, in order to capture such a phenomenon accurately on adapted meshes, one has to predict the evolution path. Here, we propose a new adaptive algorithm for time‐dependent simulation; the idea is to solve a transient fixed problem by introducing a new loop in the adaptation scheme. The metric used for 3D simulations is constructed with an a posteriori error estimate based on a discrete approximation of the Hessian of the solution. For time‐dependent simulation, a metric intersection in time is introduced to refine all the areas where the phenomena evolve. Copyright © 2003 John Wiley & Sons, Ltd.
An empirical investigation of the GARCH option pricing model: Hedging performance
Authors: Yung Haynes H. M. , Zhang Hua
Published: October 2003

In this article, we study the empirical performance of the GARCH option pricing model relative to the ad hoc Black‐Scholes (BS) model
of Dumas, Fleming, and Whaley. Specifically, we investigate the empirical performance of the option pricing model based on the exponential GARCH
(EGARCH) process of Nelson. Using S&P 500 options data, we find that the EGARCH model performs better than the ad hoc BS model both in
terms of in‐sample valuation and out‐of‐sample forecasting. However, the superiority of out‐of‐sample performance
EGARCH model over the ad hoc BS model is small and insignificant except in the case of deep‐out‐of‐money put options. The
out‐performance diminishes as one lengthens the forecasting horizon. Interestingly, we find that the more complicated EGARCH model performs worse
than the ad hoc BS model in hedging, irrespective of moneyness categories and hedging horizons. For at‐the‐money and
out‐of‐the‐money put options, the underperformance of the EGARCH model in hedging is statistically significant. © 2003 Wiley
Periodicals, Inc. Jrl Fut Mark 23:1191–1207, 2003
Mitoxantrone–cyclophosphamide–rituximab: an effective and safe combination for indolent NHL
Authors: Emmanouilides C. , Territo M. , Menco H. , Patel R. , Rosen P.
Published: October 2003

Treatment for extensive indolent lymphoma should combine optimization of efficacy without excessive toxicity. Rituxan may be an ideal agent for combinations with chemotherapy because of its non‐cross‐resistant toxicity profile and the potential for synergism. We present the results of 32 patients with indolent B‐cell NHL who received a novel three‐drug combination designed with the intent of preservation of both efficacy and quality of life. Patient characteristics were as follows, median age, 58 years (36–75 years); histology, follicular 16, SLL/CLL five, lymphoplasmacytic six, marginal cell five; relapsed or refractory, 10; untreated, 22. Patients first received cyclophosphamide 800 mg/m2 and mitoxantrone 8 mg/m2, iv on the same day, every 3 weeks for two cycles. Subsequently, patients received rituximab followed by mitoxantrone 8 mg/m2 every 2 weeks for four cycles. The regimen, and particularly rituximab, was extremely well tolerated. Grade I/II, infusion‐related toxicity was noted in 10%. Six patients achieved a PR and 23 a CR for an overall response of 90% (95% CI: 79–100%). The actuarial median TTP for all patients was 30 months. Molecular remissions were noted in 8/14 patients tested in CR. We conclude that the cyclophosphamide–mitoxantrone–rituxan (CyMiR) regimen is effective and extremely well tolerated. Furthermore, rituximab infusion‐related morbidity is nearly completely eliminated. Copyright © 2003 John Wiley & Sons, Ltd.
ABCG2 (BCRP) expression in normal and malignant hematopoietic cells
Authors: Abbott Brian L.
Published: October 2003

ABCG2 (BCRP) is a member of the ATP‐binding cassette (ABC) family of cell surface transport proteins. ABCG2 expression occurs in a variety of normal tissues, and is relatively limited to primitive stem cells. ABCG2 expression is associated with the side population (SP) phenotype of Hoechst 33342 efflux. The substrate profile of ABCG2 includes the antineoplastic drugs primarily targeting topoisomerases, including anthracyclines and camptothecins. More recently, pheophorbide, a chlorophyll‐breakdown product, and protoporhyrin IX have been described as ABCG2 substrates, perhaps indicating a physiologic role of cytoprotection of primitive cells. Also, mice lacking ABCG2 expression have no intrinsic stem cell defects, although there is a remarkable increase in toxicity with antineoplastic drugs that are ABCG2 substrates, and also a photosensitivity resembling protoporphyria. Like other members of the ABC family, such as MDR1 and MRP1, ABCG2 is expressed in a variety of malignancies. Despite numerous reports of ABCG2 expression in AML, there is little evidence that ABCG2 expression is correlated with an adverse clinical outcome. This review will focus on the potential usefulness of ABCG2 as a marker primitive stem cells and possible physiologic roles of ABCG2 in protection of primitive stem cell populations, and potential methods of overcoming ABCG2‐associated drug resistance in anticancer therapy. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of [N‐methyl‐11C]‐3‐[(6‐dimethylamino)pyridin‐3‐yl]‐2,5‐dimethyl‐N, N‐dipropylpyrazolo[1,5‐a]pyrimidine‐7‐amine: A potential PET ligand for in vivo imaging of CRF1 receptors
Authors: Kumar J.S. Dileep , Majo Vattoly J. , Prabhakaran Jaya , Simpson Norman R. , Van Heertum Ronald L. , Mann J. John
Published: October 2003

A convenient synthesis of [N‐methyl‐11C]‐3‐[(6‐dimethylamino)pyridin‐3‐yl]‐2,5‐dimethyl‐N,N‐dipropylpyrazolo[1,5‐a]pyrimidine‐7‐amine (R121920), a highly selective CRF1 antagonist has been developed as a potential PET ligand. 3 ‐ [(6 ‐ methylamino)pyridin ‐ 3 ‐ yl]‐2,5‐dimethyl‐N,N‐dipropylpyrazolo [1,5‐a]pyrimidine‐7‐amine (7), the precursor for radiolabelling was synthesized through a novel palladium catalyzed Suzuki coupling of aryl bromide 5 with heteroaryl boronate ester 4. The requisite boronate ester 4 was synthesized in four steps from 2‐amino‐4‐bromopyridine in 50% overall yield. Although the synthesis of cold R121920 proceeded in 93% yield by sodium hexamethyl‐disilazide (NaHMDS) mediated N‐methylation of the desmethylamine 7 at −78°C, the attempted radiosynthesis under various conditions using conventional bases were not successful. However, the radiolabeling of [11C]R121920 was successfully carried out with [11C]MeOTf in acetone at −20°C in the absence of added basic reagents. The radiotracer was purified by RP‐HPLC followed by RP‐solid phase extraction. The yield of the reaction was 5% (at EOB) and the specific activity was >1000 Ci/mmol (at EOB) with a radiochemical purity >99%. Copyright © 2003 John Wiley & Sons, Ltd.
Reductive N‐alkylation of secondary amines with [2‐11C]acetone
Authors: van der Meij Margaretha , Carruthers Nicholas I. , Herscheid Jacobus D.M. , Jablonowski Jill A. , Leysen Josee E. , Windhorst Albert D.
Published: October 2003

The development of a labeling method for secondary amines with [2‐11C]acetone is described since the R2N‐isopropyl moiety is present in many biologically active compounds. The influence of a variety of parameters (e.g. reagents, solvents, temperature, and time) on the reaction outcome is discussed. Under the optimal reaction conditions, [11C]1‐isopropyl‐4‐phenylpiperazine ([11C]iPPP) was synthesized from [2‐11C]acetone and 1‐phenylpiperazine in a decay‐corrected radiochemical yield of 72%. The overall synthesis time, from EOB to HPLC analysis of [11C]iPPP, was 20 min. Specific activity was 142–208 GBq/μmol at the end of synthesis. Copyright © 2003 John Wiley & Sons, Ltd.
Expedient synthesis of [18F]‐labeled α‐trifluoromethyl ketones
Authors: Surya Prakash G. K. , Alauddin Mian M. , Hu Jinbo , Conti Peter S. , Olah George A.
Published: October 2003

Several [18F]‐labeled α‐trifluoromethyl ketones have been synthesized. Reactions of 2,2‐difluoro‐1‐aryl‐1‐trimethylsiloxyethenes (1a–d) with [18F]‐F2 at low temperature produced [18F]‐labeled α‐trifluoromethyl ketones (2a–d). Radio‐labeled products were isolated by purification with column chromatography in 22–28% yields, decay corrected (d.c.) in three runs per compound. Radiochemical purity was >99% with specific activities 15–20 GBq/mmol at the end of synthesis (EOS). The synthesis time was 35–40 min from the end of bombardment (EOB). This one‐step simple method is highly useful for the radiochemical synthesis of potential biologically active [18F]‐labeled α‐trifluoromethyl ketones for PET imaging. Copyright © 2003 John Wiley & Sons, Ltd.
Interscanner reproducibility of cardiovascular magnetic resonance T2* measurements of tissue iron in thalassemia
Authors: Westwood Mark A. , Anderson Lisa J. , Firmin David N. , Gatehouse Peter D. , Lorenz Christine H. , Wonke Beatrix , Pennell Dudley J.
Published: October 2003

Purpose

To assess interscanner reproducibility of tissue iron measurements in patients with thalassemia using gradient echo T2* measurements on two different MRI scanners.

Materials and Methods

Twenty‐five patients with thalassemia major had liver and myocardial T2* assessment using a Picker Edge 1.5T Scanner and a Siemens Sonata 1.5T scanner, with similar gradient echo sequences. In a subset of 13 patients, two scans on the Siemens scanner were performed to assess interstudy reproducibility.

Results

There was a highly significant, linear correlation between T2* values obtained for both the heart (r = 0.95) and the liver (r = 0.99) between scanners. The mean difference, coefficient of variability, and 95% confidence intervals between scanners were 0.8 msec, 9.4% and –5.0 to 6.7 msec for the heart; and 0.9 msec, 7.9% and –2.0 to 3.9 msec for the liver. The interstudy mean difference and coefficient of variability on the Siemens scanner was 0.3 msec and 4.8% (r = 0.99) for the heart, and 0.04 msec and 1.9% (r = 0.99) for the liver.

Conclusion

The T2* technique for measuring tissue iron is reproducible between the two manufacturers' scanners. This suggests that the widespread implementation of the technique is possible for clinical assessment of myocardial iron loading in thalassemia. J. Magn. Reson. Imaging 2003;18:616–620. © 2003 Wiley‐Liss, Inc.
Event‐related analysis for event types of fixed order and restricted spacing by temporal quantification of trial‐averaged fMRI time courses
Authors: Ruge Hannes , Brass Marcel , Lohmann Gabriele , von Cramon D. Yves
Published: October 2003

Purpose

To develop a method for event‐related fMRI that allows rapidly presented event sequences to be analyzed, without requiring transitions of different event‐types to be counterbalanced.

Materials and Methods

A cued task switching procedure was investigated with an experimental trial comprising a visual task cue that indicated how to process a subsequent visual target stimulus. Cue and target were either presented quasi‐simultaneously, separated by a 100 msec cue‐target‐interval (CTI100), or the target presentation was delayed by 2000 msec (CTI2000). To characterize the trial‐related BOLD‐response in terms of its temporal relation to the underlying event structure, the pattern of onset latency differences and peak latency differences for CTI2000 minus CTI100 was evaluated. Independent estimates of onset latencies and peak latencies were determined for preprocessed trial‐averaged time courses by jackknife resampling.

Results

Validating results were obtained for two brain areas with known characteristics: the visual cortex (cue‐locked plus target‐locked activation) and the motor cortex (response‐locked activation). Extending the analysis to prefrontal areas with a priori unknown characteristics differentiated between several meaningful temporal activation patterns.

Conclusion

The method yielded a fine‐grained temporal description of trial‐related BOLD‐responses that could be successfully used for the event‐related analysis of an experimental design that was highly restricted with respect to event order and event spacing. J. Magn. Reson. Imaging 2003;18:599–607. © 2003 Wiley‐Liss, Inc.
Biochemical changes associated with mushroom browning in Agaricus bisporus (Lange) Imbach and Pleurotus florida (Block & Tsao): commercial implications
Authors: Rajarathnam Somasundaram , Shashirekha Mysore Nanjarajurs , Rashmi Sudhir
Published: October 2003

Biochemical changes associated with mushroom browning in Agaricus bisporus and Pleurotus florida were studied. With increasing storage temperature from 0 to 25 °C there was an increase in phenol oxidase activity up to 15 °C followed by a decrease at 25 °C in both mushrooms. Loss of water content in fresh mushrooms had a direct relationship with phenol oxidase activity, which could be correlated with the visual degree of mushroom browning. A bisporus displayed higher phenol oxidase activity, about two to three times that of P florida. The phenol oxidase activity in both mushroom varieties was studied on a range of phenolic compounds with diverse functional groups. A bisporus exhibited intense reactions to tyrosine and catechol, while P florida did so to guaiacol and catechol. The two mushrooms differed in the degree of their oxidation reactions relative to the functional groups. In A bisporus the skin had more phenolics than the flesh; P florida contained fewer phenolics, while the stalks of both mushrooms had low phenolics contents. FTIR spectral studies of intact mushrooms during browning showed a characteristic decrease in phenolic hydroxyls; first‐derivative spectra were used to assess relative peak intensities. Of the chemicals tested for their effect on phenol oxidase activity, 0.1 M sodium carbonate favoured the immediate development of an orange chromogen in P florida, while mild alkaline solutions favoured the enzyme activity, and acidic solutions at the 0.1 M level completely inhibited the browning reaction in both mushrooms. Copyright © 2003 Society of Chemical Industry
Evidence for the involvement of lipoxygenase in the oxidative processes associated with the appearance of green staining alteration in the Gordal olive
Authors: Gallardo‐Guerrero Lourdes , Jarén‐Galán Manuel , Hornero‐Méndez Dámaso , Mínguez‐Mosquera Ma Isabel
Published: October 2003

Lipoxygenase (LOX) activity and chloroplast pigment content were monitored during fruit growth in Gordal and Manzanilla olive varieties (Olea europaea regalis and Olea europaea pomiformis respectively). At all growth stages, LOX activity was greater in Gordal than in Manzanilla, and in both varieties, enzymatic activity peaks coincided with the maximum presence of oxidised chlorophyll pigments in the fruits. The higher lipid peroxidation potential measured directly in vitro and indirectly in vivo in the Gordal variety and its correspondence with higher contents of oxidised catabolites of chlorophyll suggested a greater tendency and sensitivity of this variety to oxidative processes. This could also explain the high organelle disorganisation levels reached during industrial processing of the fruit, allowing the formation of copper–chlorophyll complexes associated with the green staining alteration that affects Gordal olives. Copyright © 2003 Society of Chemical Industry
Meat production using four terminal pig lines
Authors: Rauw Wendy M , Varona Luis , Raya Luis Gomez , Noguera José Luis
Published: October 2003

The influence of terminal sire (Duroc (D1 and D2), Large White/Pietrain (LW/P) and Large White (LW)) on several meat production and meat quality traits was investigated in 452 male and female offspring of Landrace/Large White dams. Age at slaughter, carcass length, carcass weight and dressing yield were similar for all lines, as was the production of shoulders, chops, and ribs with bacon. D2‐sired pigs produced more noble pieces as a percentage of their carcass weight than the other three lines. LW/P‐ and LW‐sired pigs were generally leaner than Duroc‐sired pigs. LW/P and LW pigs had the highest percentage of cuts (longissimus dorsi and semimembranosus muscle) classified as pale, soft and exudative (PSE) meat. There were no large differences between the lines in the occurrence of dark, firm and dry (DFD) cuts. Copyright © 2003 Society of Chemical Industry
Studies on antioxidant activities of mucuna seed (Mucuna pruriens var utilis) extract and various non‐protein amino/imino acids through in vitro models
Authors: Siddhuraju Perumal , Becker Klaus
Published: October 2003

The antioxidant activities of a methanolic extract of mucuna beans (Mucuna pruriens var utilis) and several non‐protein amino/imino acids, namely L‐3,4‐dihydroxyphenylalanine (L‐dopa), L‐3‐carboxy‐6,7‐dihydroxy‐1,2,3,4‐tetrahydroisoquinoline (compound I), (−)‐1‐methyl‐3‐carboxy‐6,7‐dihydroxy‐1,2,3,4‐tetrahydroisoquinoline (compound II) and 5‐hydroxytryptophan (5‐HTP), were evaluated. By virtue of their hydrogen‐donating ability, all the tested compounds and the mucuna seed extract showed excellent reducing power, with the highest values being recorded for L‐dopa in a dose‐dependent manner. Similarly, as compared with synthetic antioxidants (BHT and BHA) and quercetin, all the tested compounds and the seed extract were found to be more potent in free radical‐scavenging activity (P < 0.05) against α,α‐diphenyl‐β‐picrylhydrazyl (DPPH•) radicals. Hydroxyl radicals (OH•) and superoxide anion radicals (O2•−) were effectively scavenged by the tested compounds, with the exception that no scavenging activity of 5‐HTP was observed on (O2•−) up to a concentration of 2 mg ml−1, as was also the case for BHA. Among the tested non‐protein amino/imino acids and seed extract the highest peroxidation‐inhibiting activity (95%) was recorded for 5‐HTP. On the other hand, in the linoleic acid/β‐carotene‐bleaching system, L‐dopa, compound I and compound II acted as pro‐oxidants, whereas the seed extract showed only weak antioxidant activity as in the linoleic acid emulsion system. Copyright © 2003 Society of Chemical Industry
New Phosphonated Methacrylates: Synthesis, Photocuring and Study of their Thermal and Flame‐Retardant Properties
Authors: Youssef Boulos , Lecamp Laurence , Khatib Wassef El , Bunel Claude , Mortaigne Bruno
Published: October 2003

In this work, a new methacrylate phosphonate monomer synthesis was described according to two routes: firstly, by condensation of methacrylic acid with a phosphonate epoxide and secondly by an esterification between methacryloyl chloride and a phosphonate diol. The photoinduced polymerization of this new monomer was studied as a function of reaction temperature. The optimal conversion of the photopolymerization was 81% for temperatures below 60 °C. Above 60 °C, the existence of a thermal polymerization leads to a decrease in the apparent photochemical yield. This new monomer is less reactive than the commercial dimethacrylate polyether of Bisphenol A we have used for copolymerization. Mechanical and thermal properties of the final copolymers were studied as a function of methacrylate phosphonate monomer content. Tg of the copolymers reaches a maximum when the phosphorus content is about 2%. The addition of phosphorus leads to an improvement of the thermal and flame‐retardant properties. Thus, addition of 2% phosphorus allows us to decrease the degradation rate, to increase the amount of remaining residue after combustion up to 12%, and finally to increase the Limiting Oxygen Index (LOI) from 16.8 (0% P) to 21.4 (2% P).

Synthetic routes to methacrylate phosphonated monomer.

magnified image

Synthetic routes to methacrylate phosphonated monomer.
A Study of Epoxy‐Amine Cure Kinetics by Combining Isoconversional Analysis with Temperature Modulated DSC and Dynamic Rheometry
Authors: Sbirrazzuoli Nicolas , Vyazovkin Sergey , Mititelu Alice , Sladic Cyril , Vincent Luc
Published: October 2003

The kinetics of curing of diglycidyl ether of bisphenol A (DGEBA) with m‐phenylenediamine (m‐PDA) has been studied by using DSC under isothermal and nonisothermal conditions. An advanced isoconversional method has been applied to the data in order to evaluate a dependence of the effective activation energy on the extent of conversion. The method has been applied to the stoichiometric system as well as to the system with an excess of the amine. The nonstoichiometric system demonstrates an effective activation energy that is practically independent of the extent of conversion. The resulting value (≈55 kJ · mol−1) provides an estimate for the curing reaction of the primary amine. The stoichiometric system demonstrates a decreasing activation energy for both isothermal and nonisothermal cures. The value varies from ≈55 kJ · mol−1 to as low as ≈20 kJ · mol−1. The decrease is explained by shifting the rate determining step from a kinetic to a diffusion regime. The diffusion control is associated with the processes of gelation and vitrification that occur on curing and cause a dramatic decrease in molecular mobility. Dynamic rheometry and temperature modulated DSC have been employed to study these processes.

Eα‐dependencies obtained for curing the stoichiometric (open symbols) and nonstoichiometric (solid symbols) epoxy systems (circles: nonisothermal conditions; triangles: isothermal cures).

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Eα‐dependencies obtained for curing the stoichiometric (open symbols) and nonstoichiometric (solid symbols) epoxy systems (circles: nonisothermal conditions; triangles: isothermal cures).
Environmentally Friendly Negative Resists Based on Acid‐Catalyzed Acetalization for 193‐nm Lithography
Authors: Kim Jin‐Baek , Jang Ji‐Hyun , Ko Jong‐Sung , Choi Jae‐Hak , Lee Kwan‐Ku
Published: October 2003

Novel water‐developable negative resists were designed to induce both crosslinking and polarity change upon exposure and bake. The matrix polymers were synthesized by copolymerization of glyceryl methacrylate and methacrolein. The acid‐catalyzed acetalization of the polymer induced crosslinking, polarity change, and an increase in dry‐etch resistance. The resist formulated with this polymer and cast in a water/ethanol mixture showed 0.7 μm line and space patterns using a mercury–xenon lamp in a contact printing mode and pure water as a developer.

The acid‐catalyzed acetalization of poly(GMA‐co‐MA) to form the water‐insoluble acetal.

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The acid‐catalyzed acetalization of poly(GMA‐co‐MA) to form the water‐insoluble acetal.
On/off switching on polymer conformation
Authors: Yoshikawa Kenichi
Published: October 2003

The manner of folding transition from elongated coil to compact globule of single polymer chain is discussed. Based on theoretical consideration, it is argued the semi‐flexible polymer chain exhibits large discrete transition on the level of individual single chains, whereas the transition looks continuous, or cooperative, on the ensemble of chains. As the experimental verification, in the present article thermodynamic and kinetic aspects of folding transition of single giant DNA molecules are described. It is shown that rich variety of nano‐ordered structures are obtained from single DNA molecules through suitable setup of the experimental conditions. The stability of such nano‐structures generated from single polymer chain is discussed in relation to the ordered compact structure with large number of chains in semi‐dilute and concentrated polymer solutions.
Polymer‐modification of an anti‐cancer drug: effects on hydrodynamic properties
Authors: Sohn Jung‐Sun , Choi Soo‐Kyung , Jo Byung‐Wook , Hess Michael , Zähres Manfred
Published: October 2003

Coupling of a hydrophobic pharmaceutical agents with the hydrophilic poly(ethylene oxide) chain can make the drug water soluble which is necessary for some applications. The modification of the polymer chain results in a different solution behaviour of the macromolecules compared with the unmodified polymer. There are strong indications that shape and rigidity of the modified molecule differ significantly from the simple chain. Some results from measurements of the self‐diffusion coefficient and solution viscosity are discussed. The results are important for further engineering on active drug systems.
New biodegradable polymers for delivery of bioactive agents
Authors: Kwon Young Min , Kim Sung Wan
Published: October 2003

Biodegradable, thermosensitive triblock copolymer, PLGA‐PEG‐PLGA, can be easily fabricated into drug‐loaded microspheres or injectable in situ hydrogel system for protein or water‐insoluble drugs without use of organic solvent. Aqueous‐based microsphere exhibited continuous release of intact insulin in vitro for 3 weeks while the microspheres prepared using dichloromethane showed initial burst and incomplete release. Confocal miscoscopy images of microspheres corroborated the release pattern. Next study with an injectable in situ hydrogel (ReGelTM) exhibited zero‐order insulin release in vitro and sustained plasma insulin level for 2 weeks in vivo upon single subcutaneous injection in SD rats.
The processing of starch as a thermoplastic
Authors: Stepto R.F.T.
Published: October 2003

The thermoplastics processing of native starch in the presence of water is a recent development with very wide possible applications. Eventually, oil‐based polymer materials have to be replaced in many applications by sustainable, inexpensive, natural materials from renewable resources. As with conventional thermoplastics, starch‐water melts may be processed by injection moulding and extrusion. The present contribution focuses on injection moulding. The bases of the processing and the thermal and molecular changes occurring are described. In addition, the rheological behaviour of the starch‐water melts during processing is analysed quantitatively to give apparent melt viscosities. The dimensional, thermal and mechanical properties of moulded thermoplastic starch polymer (TSP) materials and the products presently being produced from them are discussed.
Assessing the economic and ecological impact of plastic products
Authors: Feuerherd Karl‐Heinz
Published: October 2003

The framework of the International Standard Organization's (ISO) 14040 series provides the practitioner with rules to deal with different aspects of analysis and assessment of the life cycle of products. The standard emphasizes the importance of accurate data to perform a valid analysis. This premise lets LCA (life cycle assessment) studies become time‐consuming and expensive. But, sound decision‐making by management in enterprises can be done even in cases where data are incomplete or vary, when the eco‐efficiency analysis methodology is used that has been developed and applied by BASF in more than 150 projects during the last five years.
New methodology for synthesizing polyolefinic graft block copolymers and their morphological features
Authors: Kashiwa Norio , Kojoh Shin‐ichi , Kawahara Nobuo , Matsuo Shingo , Kaneko Hideyuki , Matsugi Tomoaki
Published: October 2003

This paper describes a new synthetic route for polyolefinic graft block copolymers by adopting coupling reaction between terminally hydroxylated polyolefins and maleic anhydride grafted polyolefins. Terminally hydroxylated polypropylene (PP‐OH) was coupled with maleic anhydride modified polyethylene (PE‐g‐MAH) and such ethylene‐propylene random copolymer (EPR‐g‐MAH) to give polyolefinic graft block copolymers (PE‐g‐PP and EPR‐g‐PP, respectively). The formation of PE‐g‐PP was confirmed by enhancement on molecular weight and it brought about distinctive decrease in size of dispersed domain in its phase separation morphology. Occurrence of coupling reaction to give EPR‐g‐PP was indicated by extreme decrease in its solubility to n‐decane and it led to unique morphology demonstrating lamella microstructure that had never been reported for a comparable polyolefin composite.
A fluorescence study on critical exponents during sol‐gel phase transition in complex monomeric systems
Authors: Kaya Demet , Pekcan Önder
Published: October 2003

Methyl methacrylate (MMA), ethyl methacrylate (EMA) and various combinations of MMA with EMA were used during FCC experiments. Pyrene (Py) was introduced as a fluorescence probe and fluorescence lifetimes from its decay traces were measured during sol‐gel phase transitions. The fast transient fluorescence (FTRF) technique was used to study the critical exponents during sol‐gel phase transition in free‐radical crosslinking copolymerization (FCC). The results were interpreted in the view of percolation theory. The critical exponents of gel fraction, β and weight average degree of polymerization, γ were measured near the point of gel effect and found to be around 0.37 ± 0.015 and 1.69 ± 0.05 in all systems studied respectively.
Study of nucleation induced structure modification in isotactic polypropylene by DMTA and solid state NMR
Authors: Romankiewicz Anna , Jurga Jan , Sterzynski Tomasz
Published: October 2003

Isotactic polypropylene (iPP) modified by heterogeneous nucleation and molten state drawing was investigated using the DMTA and NMR methods. The nucleation was realized by specific α and β nucleating agents, 1,3,2,4‐bis(3,4‐dimetylobenzylideno) sorbitol (Millad 3988, Miliken) leading to the creation of the α phase, and N,N′‐dicyklohexylo‐2,6‐naftaleno dikarboxy amid (NJ100) as the β phase promoter. The processing induced modification was performed by molten state drawing during an extrusion in the range between the die exit and the calibration unit. An increase of the glass transition temperature of iPP was found to be drawing independent for the β‐nucleated samples, and dependent in the case of the α‐iPP. Changes in the macromolecular mobility, depending on the α/β iPP structure and molten state drawing, was found by NMR lineshape and second moment measurements.
Kinetics of reactions of coal with polystyrene: TGA‐DSC approach
Authors: Straka P. , Náhunková J. , Brožová Z.
Published: October 2003

Kinetics of thermal reactions of coal with polystyrene by TGA and DSC methods was studied. In the range of about 350‐550°C a thermal degradation of coal proceeds, and gas, tar and coke are evolved. Simultaneously, decomposition of polystyrene occurs (360‐470°C). Unsaturated products of polystyrene decomposition are hydrogenated by coal, because coal is a strong H‐donor. Moreover, some aromatic products react with coal tar structures and new aromates are formed. The yield of tar from copyrolysis is then higher in comparison with pyrolysis of coal alone. Kinetic parameters of the process were evaluated and discussed.
Chaos and synchronization of Colpitts oscillators
Authors: Li Guo‐Hui
Published: October 2003

In this work we numerically investigate the nonlinear dynamics of the Colpitts oscillator. Bifurcation diagrams of consecutive plots of the values of electrical current minima are presented, according to the circuit parameters. By following observer‐based synchronization, two identical Colpitts oscillators with scalar transmitted signals are developed. Computer simulation results are given. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 446–449, 2003
Effect of device gain compression on V‐band pHEMT mixer performance
Authors: Brabetz T. , Buchanan N. B. , Fusco V. F.
Published: October 2003

An examination of conversion gain compression impact on mixer performance at 65 GHz demonstrates that the compression properties of upconverters are inherently worse than those of downconverters, and that narrow‐gate devices (when used in downconverters) and wide‐gate devices (when used in upconverters) yield the best conversion‐gain performance characteristics. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 468–469, 2003
New configurations of single‐ and multi‐level bandpass filters with excellent harmonic suppression
Authors: Gururajan Kala , Peddibhotla Harish , Settaluri Raghu K.
Published: October 2003

New configurations of high‐frequency quasi‐lumped capacitive configurations and composite structures with application to bandpass filters are presented. These structures show distinct advantages that facilitate compactness and higher harmonic suppression and have been analyzed according to suitable network models. Simple design equations have been used to synthesize new filter configurations, which exhibit excellent higher‐order harmonic suppression. The proposed new designs have been validated by measurement. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 490–493, 2003
Characterization of cell‐ and region‐specific abnormalities in the epididymis of cathepsin a deficient mice
Authors: Korah Nadine , Smith Charles E. , d'Azzo Alessandra , Mui Jeannie , Hermo Louis
Published: October 2003

Cathepsin A (PPCA), a lysosomal carboxypeptidase that functions as a protective protein for α‐neuraminidase and β‐galactosidase in a multi‐enzyme complex, has been shown to be expressed in the epithelial cells of the epididymis. In the present study, the epididymis of PPCA−/− mice from 2 to 10 months of age was compared with those of their wild‐type counterparts. Major accumulations of pale vacuoles, corresponding to lysosomes, were noted in principal and narrow/apical cells in PPCA−/− mice, and clear cells also appearing highly vacuolated, were grossly enlarged in size. This was especially evident in the caput and corpus regions, where quantitative analyses confirmed that the epithelium of the tubules in these regions was expanding in profile area. In addition, the base of the epithelium in these regions was often greatly vacuolated, corresponding to cells that presented no identifiable features and appeared to be degenerating. Halo cells dispersed at various levels in the epithelium also appeared to be abnormal, accumulating pale lysosomes. Furthermore, numerous macrophages were observed in the intertubular space of the entire duct, presenting a large size and plethora of pale lysosomes. Taken together, the present data indicate major lysosomal abnormalities in the epididymis of PPCA−/− mice in a cell type and region specific manner. In addition, it is suggested that the compromised halo cells, due to PPCA deficiency within their lysosomes, cannot function properly and as a result there is a recruitment of macrophages in the intertubular space. Mol. Reprod. Dev. 66: 358–373, 2003. © 2003 Wiley‐Liss, Inc.