bluuebunny/crossref_metadata_2025 huggingface dataset:
Tyrosine hydroxylase mRNA and protein are down‐regulated by chronic clozapine in both the mesocorticolimbic and the nigrostriatal systems
Authors: Tejedor‐Real Purificación , Faucon Biguet Nicole , Dumas Sylvie , Mallet Jacques
Published: March 2003

The dopaminergic system is one of the most important targets for pharmacological treatment of schizophrenia. Despite substantial work on mechanisms of action, it is not clear which dopaminergic pathways mediate the therapeutic effects of antipsychotic drugs. It has been shown that chronic clozapine, an atypical antipsychotic, decreases dopamine levels in the mesocorticolimbic system but not in the nigrostriatal system. Because tyrosine hydroxylase is the rate‐limiting enzyme in the biosynthesis of dopamine, we studied the effect of chronic clozapine in both dopaminergic systems. We demonstrated a decrease of tyrosine hydroxylase mRNA not only in the ventral tegmental area but also in the substantia nigra, the cell body areas of the mesocorticolimbic and the nigrostriatal systems, respectively. The reduced tyrosine hydroxylase mRNA level in these areas is accompanied by an ample reduction in the tyrosine hydroxylase protein level in their corresponding axonal terminal fields, the nucleus accumbens and the striatum. There was thus discordance between the clozapine‐induced decrease of tyrosine hydroxylase mRNA and protein and the absence of an effect on dopamine levels in the nigrostriatal system. It has been suggested that reduced levels of dopamine in the mesocorticolimbic system are required for the antipsychotic effect of the drug. Therefore, the modulation of tyrosine hydroxylase gene expression by clozapine in the mesocorticolimbic system might be necessary for its antipsychotic effect; this effect might be of relevance when considering new atypical agents. © 2003 Wiley‐Liss, Inc.
Adenoviral gene transfer of GDNF, BDNF and TGFβ2, but not CNTF, cardiotrophin‐1 or IGF1, protects injured adult motoneurons after facial nerve avulsion
Authors: Sakamoto Tsuyoshi , Kawazoe Yoko , Shen Jin‐Song , Takeda Yasuo , Arakawa Yoshihiro , Ogawa Junko , Oyanagi Kiyomitsu , Ohashi Toya , Watanabe Kazutada , Inoue Kiyoharu , Eto Yoshikatsu , Watabe Kazuhiko
Published: March 2003

We examined neuroprotective effects of recombinant adenoviral vectors encoding glial cell line‐derived neurotrophic factor (GDNF), brain‐derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), cardiotrophin‐1 (CT1), insulin‐like growth factor‐1 (IGF1), and transforming growth factor‐β2 (TGFβ2) on lesioned adult rat facial motoneurons. The right facial nerves of adult Fischer 344 male rats were avulsed and removed from the stylomastoid foramen, and adenoviral vectors were injected into the facial canal. Animals avulsed and treated with adenovirus encoding GDNF, BDNF, CNTF, CT1, IGF1 and TGFβ2 showed intense immunolabeling for these factors in lesioned facial motoneurons, respectively, indicating adenoviral induction of the neurotrophic factors in these neurons. The treatment with adenovirus encoding GDNF, BDNF, or TGFβ2 after avulsion significantly prevented the loss of lesioned facial motoneurons, improved choline acetyltransferase immunoreactivity and prevented the induction of nitric oxide synthase activity in these neurons. The treatment with adenovirus encoding CNTF, CT1 or IGF1, however, failed to protect these neurons after avulsion. These results indicate that the gene transfer of GDNF and BDNF and TGFβ2 but not CNTF, CT1 or IGF1 may prevent the degeneration of motoneurons in adult humans with motoneuron injury and motor neuron diseases. © 2003 Wiley‐Liss, Inc.
Electroless Plating of Copper on Fluorinated Polyimide Films Modified by Plasma Graft Copolymerization and UV‐induced Graft Copolymerization with 4‐Vinylpyridine
Authors: Wang Wencai C. , Vora Rohit Kumar H. , Kang En T. , Neoh Koon G.
Published: March 2003

Surface modification of two types of fluorinated polyimide (FPI) films, either by plasma polymerization and deposition of 4‐vinylpyridine (4VP) or by UV‐induced graft copolymerization with 4VP under atmospheric conditions, was carried out for adhesion enhancement with the electrolessly deposited copper. X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) results revealed that the pyridine groups in the plasma polymerized 4VP (pp‐4VP) layer could be preserved to a large extent under proper glow discharge conditions. The grafted 4VP layer with well‐preserved pyridine groups was used not only as the chemisorption sites for the palladium complexes (without the need for prior sensitization by SnCl2) during the electroless plating of copper, but also as an adhesion promotion layer for the electrolessly deposited copper. The T‐peel adhesion strength of the electrolessly deposited copper with both the 4VP plasma‐polymerized FPI (pp‐4VP‐FPI) film and the 4VP graft‐copolymerized FPI (4VP‐g‐FPI) film was much higher than that of the electrolessly deposited copper with the pristine or the Ar plasma‐treated FPI films. The high adhesion strength between the electrolessly deposited copper and the surface‐modified FPI film was attributed to the fact that the plasma‐polymerized and the UV graft‐copolymerized 4VP chains were covalently tethered on the FPI surfaces, as well as the fact that these grafted 4VP polymer chains were spatially and reactively distributed into the copper matrix.

magnified image
Compatibilization of Immiscible Poly(propylene)/Polystyrene Blends Using Clay
Authors: Wang Yong , Zhang Qin , Fu Qiang
Published: March 2003

Inorganic clay was investigated as a compatibilizer for immiscible poly(propylene)/polystyrene blends. A substantial decrease in the number of polystyrene particles was seen after adding small amounts of an organically treated clay (2–5 wt.‐%) to the blends. A possible mechanism for this kind of compatibilization is discussed, but these unique and completely new findings need further verification.

Schematic representation of the intercalated structure in PP/PS/OMMT blends: (a) PP and PS confined in the same gallery of OMMT, and (b) parts of PP and PS molecules located outside the gallery serving as a compatibilizer.

magnified image

Schematic representation of the intercalated structure in PP/PS/OMMT blends: (a) PP and PS confined in the same gallery of OMMT, and (b) parts of PP and PS molecules located outside the gallery serving as a compatibilizer.
Polymerization of Cyclic Monomers, 10,
Authors: Moszner Norbert , Zeuner Frank , Fischer Urs Karl , Rheinberger Volker , Meijere Armin de , Bagutski Viktor
Published: March 2003

Methyl 2‐(bicyclo[3.1.0]hex‐1‐yl)acrylate (1) was synthesized from methyl 2‐(cyclopentene‐1‐yl)‐2‐hydroxyacetate by cyclopropanation, followed by oxidation to the corresponding bicyclic 2‐oxoacetate and Wittig olefination with methyltriphenylphosphonium bromide. Initiated with 2,2′‐azoisobutyronitrile at 65 °C in chlorobenzene, the radical homopolymerization of 1 occurred with opening of the cyclopropane ring leading to a polymer with a glass transition temperature of 90 °C. The reactivity of 1 in radical copolymerization was higher than that of methyl methacrylate.

magnified image
Scalability study of the ad hoc on‐demand distance vector routing protocol
Authors: Lee Sung‐Ju , Belding‐Royer Elizabeth M. , Perkins Charles E.
Published: March 2003

As mobile networking continues to experience increasing popularity, the need to connect large numbers of wireless devices will become more prevalent. Many recent proposals for ad hoc routing have certain characteristics that may limit their scalability to large networks. This paper examines five different combinations of modifications that may be incorporated into virtually any on‐demand protocol in order to improve its scalability. The scalability of current on‐demand routing protocols is evaluated through the selection of a representative from this class of protocols. The performance of the un‐modified on‐demand protocol is compared against that of it combined with each of the scalability modifications. Each scheme's behavior is analyzed in networks as large as 10,000 nodes through detailed simulation. Based on the observations, conclusions are drawn as to the expected scalability improvement that can be achieved by each modification. Copyright © 2003 John Wiley & Sons, Ltd.
Resource assessment and clutch size in the bean weevil, Acanthoscelides obtectus
Authors: Szentesi Árpád
Published: March 2003

Bean weevil (Acanthoscelides obtectus (Say)) females were found to use seeds (discrete resource patches) differentially when different sizes were offered in multiple‐choice tests. Females, either as a group or as individuals, laid significantly (two to six times) more eggs on large seeds than on those of five times smaller mass. In contrast, seed shape (flattened or spherical) did not contribute to clutch‐size adjustment. Thus, A obtectus females seem to measure only relative seed size when a comparison is possible. Nevertheless, females overload seeds with eggs and this can result in larval competition, so that, whereas resource size assessment and a robust egg‐load adjustment indicate a trade‐off between resource use and female fitness, it does not seem to provide much benefit for the progeny in stored dry beans. Several features, eg the use of oviposition markers and its consequences, may counterbalance the possible negative effects. It is assumed that, due to life cycle differences, females in the bean field may realise different fitness gains in comparison with those living in stores.

© 2003 Society of Chemical Industry
Glutenin and gliadin contents of flour derived from wheat infested with different aphid species
Authors: Basky Zsuzsa , Fónagy Adrien
Published: March 2003

Aphid feeding in cereals results in both quantitative and qualitative yield losses; moreover aphid‐transmitted viruses are responsible for other quantitative and qualitative damage so that direct or indirect effects of aphid infection are always of interest. At the beginning of stem elongation, wheat plants were caged regardless of the presence or absence of indigenous cereal aphids. Half of the caged plants were artificially infected with Diuraphis noxia. The number of D noxia and Rhopalosiphum padi individuals on plants destined for flour preparation was approximately 150 aphids per tiller at peak population. The number of Sitobion avenae individuals was ca 25 aphids per tiller. Bread‐making quality of wheat flour is determined primarily by the protein content, the gluten proteins (gliadins, glutenins) being the prime factors. The absolute amounts and/or the relative proportion of gliadins and glutenins are very important in dough making and in determining baking quality. Flour from grains originating from plants infected naturally with cereal aphids indigenous to Hungary, and flour infected artificially with D noxia, were analysed for glutenin and gliadin content using size exclusion HPLC. It was found that aphid infection had a significant effect on the gliadin/glutenin ratio, which was significantly lower in wheat flour prepared from aphid‐infected plants than in that from uninfected control. The most significant decrease in gliadin/glutenin ratio was caused by D noxia infection, followed by R padi and then S avenae. As the gliadin/glutenin ratio was significantly lower in flour made from aphid‐infected wheat seeds, it can be supposed that aphid feeding results in decreased bread making quality of wheat flour.

© 2003 Society of Chemical Industry
Influence of acetylcholine levels on the binding of a SPECT nicotinic acetylcholine receptor ligand [123I]5‐I‐A‐85380
Authors: Fujita Masahiro , Al‐Tikriti Mohammed S. , Tamagnan Gilles , Zoghbi Sami S. , Bozkurt Ali , Baldwin Ronald M. , Innis Robert B.
Published: March 2003

Although in vitro theory indicates that ligand binding is sensitive to competition with neurotransmitters, only some imaging ligands have shown such competition in vivo. The purpose of this study was to determine whether increases in acetylcholine (ACh) levels induced by an acetylcholinesterase inhibitor, physostigmine, inhibit in vivo binding of [123I]5‐iodo‐3‐(2(S)‐2‐azetidinyl‐methoxy) pyridine (5‐I‐A‐85380), a single photon emission computed tomography ligand for the high‐affinity type nicotinic ACh receptor (nAChR). Baboons were used for seven studies with a bolus plus constant infusion equilibrium paradigm. After achieving equilibrium at 5 h, physostigmine (0.02 (n = 1), 0.067 (n = 3), and 0.2 (n = 3) mg/kg) was administered intravenously and data were acquired for up to 8 h. To confirm equilibrium conditions, [123I]5‐I‐A‐85380 plasma levels were measured in four studies, including all studies with 0.2 mg/kg physostigmine. Prior to physostigmine administration, thalamic activities were stable, with changes of 1.1%/h or less, except in one study with a gradual increase of 4.2%/h. Thalamic activities were decreased by 15% in one study with 0.067 mg/kg and 14–17% in all studies with 0.2 mg/kg physostigmine administration (P = 0.009). In these studies with 0.2 mg/kg physostigmine administration, [123I]5‐I‐A‐85380 plasma levels showed a transient or a sustained increase after physostigmine administration that would have increased thalamic activities. These results suggest that elevated ACh levels induced by physostigmine can effectively compete in vivo with [123I]5‐I‐A‐85380 binding at nAChRs. However, decreased thalamic activities could have been caused by other mechanisms, including internalization of the receptor with an associated decreased affinity for radioligand. Synapse 48:116–122, 2003. © 2003 Wiley‐Liss, Inc.
Intramolecular rearrangements as a consequence of the dephosphorylation of phosphoaspartate residues in proteins
Authors: Napper Scott , Wolanin Peter M. , Webre Daniel J. , Kindrachuk Jason , Waygood Bruce , Stock Jeffry B.
Published: March 2003

Aspartate phosphorylation induces changes in protein conformation that are used to regulate processes ranging from gene expression and cell differentiation to cell motility and the generation of electrochemical gradients across membranes. We show here that dephosphorylation of the phosphoaspartate in the chemotaxis response regulator CheY can result in the loss of a water molecule that may be due to formation of a succinimide intermediate.
Identification of cDNAs from Japanese pufferfish (Fugu rubripes) and Atlantic salmon (Salmo salar) coding for homologues to tetrapod prion proteins
Authors: Oidtmann Birgit , Simon Dietrich , Holtkamp Nikola , Hoffmann Rudolf , Baier Michael
Published: March 2003

We identified cDNAs coding for homologues to tetrapod prion proteins (PrPs) in Atlantic salmon (Salmo salar) and Japanese pufferfish (Fugu rubripes), which were termed ‘similar to PrPs’ (stPrPs). Besides significant sequence homologies the fish stPrPs display characteristic structural features in common with tetrapod PrPs. In addition, two stPrPs were shown to be highly expressed in brain tissue. None of the so far identified PrP‐homologues of fish resembles doppel. Hence, the duplication of the PrP gene, which generated doppel, may have occurred not in fish but later in the tetrapod lineage. The identification of fish PrPs provides a basis to address concerns about a possible susceptibility of fish to prion infections.
Osmomechanical stress selectively regulates translocation of protein kinase C isoforms
Authors: Liu X. , Zhang M.I.N. , Peterson L.B. , O'Neil R.G.
Published: March 2003

Osmomechanical stress, resulting in cell swelling and activation/regulation of numerous cellular processes, may play a critical role in cell signaling by selectively regulating translocation of protein kinase C (PKC) isoforms from cytosol to membrane compartments. Western blotting of renal epithelial cell fractions demonstrated the expression of five PKC isoforms. Three of these isoforms (PKCα, PKCϵ, PKCζ) translocated to the membrane fraction upon exposure of cells to osmomechanical stress (hypotonic medium). Immunohistochemical staining of cells using isoform‐specific antibodies further demonstrated translocation of the phorbol ester‐sensitive isoforms, PKCα and PKCϵ, to both the plasma membrane and perinuclear sites, reflecting potential initial steps in regulation of specific effector pathways. Indeed, selective inhibition of PKCs indicates a potential role for PKCα in modulating a calcium influx channel. It is concluded that osmomechanical stress induces selective translocation of specific PKC isoforms, demonstrating a key role of osmomechanical stress in selectively regulating PKC‐dependent signaling pathways.
The active site of pepsin is formed in the intermediate conformation dominant at mildly acidic pH
Authors: Campos Luis Alberto , Sancho Javier
Published: March 2003

Pepsin is an aspartic protease that acts in food digestion in the mammal stomach. An optimal pH of around 2 allows pepsin to operate in its natural acidic environment, while at neutral pH the protein is denatured. Although the pH dependence of pepsin activity has been widely investigated since the 40s, a renewed interest in this protein has been fuelled by its homology to the HIV and other aspartic proteases. Recently, an inactive pepsin conformation has been identified that accumulates at mildly acidic pH, whose structure and properties are largely unknown. In this paper, we analyse the conformation of pepsin at different pHs by a combination of spectroscopic techniques, and obtain a detailed characterisation of the intermediate. Our analysis indicates that it is the dominant conformation from pH 4 to 6.5. Interestingly, its near UV circular dichroism spectrum is identical to that of the native conformation that appears at lower pH values. In addition, we show that the intermediate binds the active site inhibitor pepstatin with a strength similar to that of the native conformation. Pepsin thus adopts, in the 6.5–4.0 pH interval, a native‐like although catalytically inactive conformation. The possible role of this intermediate during pepsin transportation to the stomach lumen is discussed.
Monet's Painting under the Microscope
Authors: Dredge Paula , Wuhrer Richard , Phillips Matthew R.
Published: March 2003

An oil painting by Claude Monet, Port-Goulphar, Belle-Ile
1887 (collection of the Art Gallery of New South Wales), was examined
to determine both the identity of the pigments used by the artist in
this painting and his technique of mixing colors and laying paint on
the canvas. The extremely complex construction of the painting was
revealed by optical microscopy, scanning electron microscopy (SEM),
energy dispersive X-ray analysis (EDS), and X-ray mapping (XRM)
analysis of cross sections of paint flakes excised from damaged regions
of Port-Goulphar, Belle-Ile. Nine different pigments were
found on the painting. Many of the identified colors were modern
pigments that became available only late in the 19th century as a
result of scientific advances in pigment chemistry. Although similar
colors were available in a natural mineral form, they lacked the vivid
color of their manufactured counterparts. The use of these new
synthetic metallic oxide colors by Monet accounts for the brilliance of
his paintings. In addition, a separation between successive paint
layers was observed in some areas of paint chip cross sections,
indicating that oil-based paint was applied to paint that had dried,
and consequently, Port-Goulphar, Belle-Ile was painted over a
long period of time. This observation is contrary to the general
perception of Monet's technique of painting freely and quickly.
Explaining the Recent Decline in Domestic Violence
Authors: Farmer Amy , Tiefenthaler Jill
Published: March 2003

According to the Department of Justice (DOJ), the incidence of domestic violence decreased during the 1990s. Understanding the causes of this decline could offer important insight into designing effective policies to continue this trend. This article uses the Area‐Identified National Crime Victimization Survey (NCVS), the same data used to generate the DOJ's national estimates, merged with county‐level variables, to examine the determinants of women reporting abuse. The results indicate that there are three important factors that likely contribute to the decline: (1) the increased provision of legal services for victims of intimate partner abuse, (2) improvements in women's economic status, and (3) demographic trends, most notably the aging of the population.
Biodiversity Loss and Economic Growth: A Cross‐Country Analysis
Authors: Asafu‐Adjaye John
Published: March 2003

This article empirically examines the relationship between biodiversity loss and economic growth in light of the current debate on the effects of economic growth on environmental quality. The basic premise is that biodiversity belongs to a special class of environmental degradation because it involves complex ecosystems, the loss of which cannot be recovered by technological advances. The main finding is that although economic growth has an expected adverse effect on biodiversity, the composition of economic output can also be significant, particularly in low‐income countries. The study highlights the need to develop appropriate institutions and macroeconomic policies that allow biodiversity values to be internalized in decisionmaking processes.
Traditional Chinese Medicine Prevents Inflammation in CCL4-Related Liver Injury in Mice
Authors: Li Y. M. , Ryan P. , Batey R. G.
Published: March 2003

Alternative medicines are being increasingly used and investigated in the management of a variety of disorders. Hepatitis is a common indication for the use of alternative therapies but evidence for the efficacy of many compounds is lacking. We have utilized a well-defined model of liver injury to study the efficacy of three herbal products designed to assist in the management of liver disease. Mice were exposed to carbon tetrachloride (CCL4) given intragastrically after they had been pretreated for five days with either saline or one of four doses of silymarin extract or CH100 (a Chinese herbal medicine comprising of 19 herbs) or one of two doses of CH101 (a Chinese herbal preparation designed to reduce fibrosis). Animals were sacrificed 24 hours after receiving CCL4. Liver enzymes and hepatic histology formed the basis for evaluating efficacy of the treatments. Each of the alternative medicines reduced the alanine amino transferase (ALT) elevation demonstrated after CCL4 injection. The high dose CH100 regimen was most effective in protecting against injury and this was confirmed with hepatic histology. Other doses of CH100, CH101 and silymarin were not shown to provide protection against the histological damage. In conclusion, Silymarin, CH100 and CH101 are able to reduce ALT elevation in animals exposed to CCL4. High dose CH100 provides protection from hepatocyte necrosis in this model. The data add to our understanding of the capacity some herbal medicines have to modify the reaction of the liver to a variety of insults and suggest the value of studying these agents further in human liver diseases.
Anxiolytic Effect of Ting-Chih-Wan in Mouse Behavior Models of Anxiety
Authors: Lin Ying-Chih , Hsieh Ming-Tsuen , Chen Chung-Fung , Cheng Hao-Yuan , Peng Wen-Huang
Published: March 2003

The anxiolytic effect of the alcoholic extract of Ting-Chih-Wan (TCWa) was studied using the black and white test (BWT) and the elevated plus-maze (EPM). We further demonstrated the anxiolytic mechanism of TCWa by combining with diazepam (DIZ), serotonin (5-HT) agonists or antagonists, and measuring the levels of monoamines and its metabolites in the brain stem and cortex. In the BWT, TCWa (0.1–1.0 g/kg, p.o.) increased the time spent in the white chamber and total change between the two chambers, and decreased the time spent in the black chamber. TCWa (0.1–0.5 g/kg, p.o.) increased the arm entries and the time spent on the open arms, and decreased the arm entries and the time spent on the closed arms in the EPM. On the other hand, TCWa (1.0 g/kg, p.o.) decreased horizontal activity and prolonged pentobarbital-induced sleeping times. TCWa (0.1, 0.5 g/kg) decreased the levels of norepinephrine (NE), dopamine (DA), 5-HT and 5-hydroxy-indoleacetic acid (5-HIAA) and increased the levels of vanillylmandelic acid (VMA) and homovanillic acid (HVA) in the brain stem. TCWa (0.1 and 0.5 g/kg) decreased the levels of NE, DA and increased the levels of VMA and HVA in the cortex. TCWa also attenuated the anxiogenic effect of 5-hydroxytryptophan (5-HTP) and enhanced the anxiolytic effect of 9p-chlorophenylalanine (PCPA), buspirone (BUS) and ritanserin (RIT) in the EPM. From these results, TCWa at 0.1 and 0.5 g/kg posessed an anxiolytic effect. The anxiolytic mechanisms of TCWa might be due to decreased catecholaminergic activity caused by the increase in the turnover rate of catecholamines in the brain and decreased concentrations of 5-HT in the brain stem via activating somatodendritic 5-HT1A autoreceptors and inhibiting postsynaptic 5-HT2 receptors.
CLASSIFICATION OF BINARY SPATIAL TEXTURES USING STOCHASTIC GEOMETRY, NONLINEAR DETERMINISTIC ANALYSIS AND ARTIFICIAL NEURAL NETWORKS
Authors: MATTFELDT TORSTEN
Published: March 2003

Stereology and stochastic geometry can be used as auxiliary tools for diagnostic purposes in tumour pathology. The role of first-order parameters and stochastic–geometric functions for the classification of the texture of biological tissues has been investigated recently. The volume fraction and surface area per unit volume, the pair correlation function and the centred quadratic contact density function of epithelium were estimated in three case series of benign and malignant lesions of glandular tissues. This approach was further extended by applying the Laslett test, i.e. a point process statistic computed after transformation of the convex tangent points of sectioned random sets from planar images. This method has not yet been applied to histological images so far. Also the nonlinear deterministic approach to tissue texture was applied by estimating the correlation dimension as a function of embedding dimension. We used the stochastic–geometric functions, the first-order parameters and the correlation dimensions for the classification of cases using various algorithms. Learning vector quantization was applied as neural paradigm. Applications included distinction between mastopathy and mammary cancer, between benign prostatic hyperplasia and prostatic cancer, and between chronic pancreatitis and pancreatic cancer. The same data sets were also classified with discriminant analysis and support vector machines. The stereological estimates provided high accuracy in the classification of individual cases. The question: which category of estimator is the most informative, cannot be answered globally, but must be explored empirically for each specific data set. The results obtained by the three algorithms were similar.
A MULTIPLICITY RESULT FOR ELLIPTIC EQUATIONS AT CRITICAL GROWTH IN LOW DIMENSION
Authors: DEVILLANOVA GIUSEPPE , SOLIMINI SERGIO
Published: March 2003

We consider the problem -Δu = |u|2*-2u + λu in Ω, u = 0 on ∂Ω, where Ω is an open regular subset of ℝN (N ≥ 3), [Formula: see text] is the critical Sobolev exponent and λ is a constant in ]0, λ1[ where λ1 is the first eigenvalue of -Δ. In this paper we show that, when N ≥ 4, the problem has at least [Formula: see text] (pairs of) solutions, improving a result obtained in [4] for N ≥ 6.
Essential role of theC. elegansArp2/3 complex in cell migration during ventral enclosure
Authors: Sawa Mariko , Suetsugu Shiro , Sugimoto Asako , Miki Hiroaki , Yamamoto Masayuki , Takenawa Tadaomi
Published: March 2003

Migration of cells through the reorganization of the actin cytoskeleton is essential for morphogenesis of multicellular animals. In a cell culture system, the actin-related protein (Arp) 2/3 complex functions as a nucleation core for actin polymerization when activated by the members of the WASP(Wiskott-Aldrich syndrome protein) family. However, the regulation of cell motility in vivo remains poorly understood. Here we report that homologues of the mammalian Arp2/3 complex and N-WASP in Caenorhabditis elegansplay an important role in hypodermal cell migration during morphogenesis, a process known as ventral enclosure. In the absence of one of any of the C. elegans Arp2/3 complex subunits (ARX-1, ARX-2, ARX-4, ARX-5, ARX-6 or ARX-7) or of N-WASP (WSP-1), hypodermal cell migration led by actin-rich filopodia formation is inhibited during ventral enclosure owing to the reduction of filamentous actin formation. However, there is no effect on differentiation of hypodermal cells and dorsal intercalation. Disruption of the function of ARX-1 and WSP-1 in hypodermal cells also resulted in hypodermal cell arrest during ventral enclosure, suggesting that their function is cell autonomous. WSP-1 protein activated Arp2/3-mediated actin polymerization in vitro. Consistent with these results, the Arp2/3 complex and WSP-1 colocalized at the leading edge of migrating hypodermal cells. The stable localization of WSP-1 was dependent on the presence of Arp2/3 complex,suggesting an interaction between the Arp2/3 complex and WSP-1 in vivo.
Molybdenum Phosphide: A Novel Catalyst for Hydrodenitrogenation
Authors: Li Wei , Dhandapani Balamurugan , Oyama S Ted
Published: March 2003

A single phase molybdenum phosphide, MoP, with a moderate surface area was prepared using temperature programmed reduction of an amorphous phosphate precursor and the so-prepared sample was found to be a good catalyst for hydrodenitrogenation.
Direct Observation of Cation Complexation of 18-Crown-6 by Atomic Force Microscopy Using Chemically Modified Tips
Authors: Kado Shinpei , Kimura Keiichi
Published: March 2003

Intermolecular forces between 18-crown-6 and guest ions have been measured by atomic force microscopy using AFM tips modified chemically with an alkylsilane derivative having 18-crown-6 moiety. The greater adhesion forces were observed with the crown-ether modified tip than with bare tips on mica substrate in aqueous solutions containing K+, probably due to the complexation between 18-crown-6 moiety on tip and K+ in solution. Specific interactions based on cation complexation of 18-crown-6 have been observed in ethanol on mica substrate treated with (3-aminopropyl)triethoxysilane (–NH3+).
Characterization of Surface Structure of Silica Thin Films by Auger Parameter
Authors: Tomita Rie , Urano Satoshi , Kohiki Shigemi
Published: March 2003

Si Auger parameter of silica films obtained under different hydrolysis conditions was calculated in order to determine SiOH concentration. It was found that the Auger parameter increased with increasing silicate molecular. Silica films with a large Auger parameter were observed by transmission electron microscope (TEM) to consists of a large diameter particle than films with a small Auger parameter. Increased silica particle diameter demonstrates that the condensation reaction proceeds to an extent that the concentration of OH groups has decreased. It has been concluded that silica film surfaces with a large Auger parameter had few OH groups per Si atom.
Does Photoisomerization Proceed in an Ionic Liquid?
Authors: Ozawa Ryosuke , Hamaguchi Hiro-o
Published: March 2003

Photoisomerization of trans-stilbene has been investigated in an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate([bmim]PF6). It has been found that the photo-isomerization indeed proceeds in this ionic liquid with a rate much larger than that expected from its polarity and shear viscosity.
A Novel LiCl/H-STI Zeolite Guest/Host Assembly Material with Superior Humidity Sensitivity: Fabrication and Characterization
Authors: Zou Jing , He He-Yong , Dong Jun-ping , Long Ying-cai
Published: March 2003

A thermal dispersion method was used for assembling LiCl (the guest) into H-STI zeolite (the host) with a two-dimensional channel system of appropriate pore sizes to develop a novel guest/host material with excellent sensitivity, linearity and fast response to humidity change. The assembly process was investigated by the methods of XRD and 7Li MAS-NMR.
New Monodisperse Ethylene–Propylene Copolymers and a Block Copolymer Created by a Titanium Complex Having Fluorine-Containing Phenoxy-Imine Chelate Ligands
Authors: Kojoh Shin-ichi , Matsugi Tomoaki , Saito Junji , Mitani Makoto , Fujita Terunori , Kashiwa Norio
Published: March 2003

New monodisperse ethylene–propylene copolymers and a block copolymer, highly syndiotactic polypropylene-b-poly(ethylene-co-propylene), were synthesized with a titanium complex having fluorine-containing phenoxy-imine chelate ligands, an FI Catalyst, using methylalumoxane (MAO) as a cocatalyst. Analysis using transmission electron microscopy (TEM) suggests that the well-defined block copolymer possesses high potential as a compatibilizer.
Degradation of Dibutyl Phthalate in Water by the Aid of Metals under γ-Ray Irradiation
Authors: Yoshida Tomoko , Tanabe Tetsuo , Miyashita Yoshinori , Yoshida Hisao , Hattori Tadashi
Published: March 2003

The degradation of dibutyl phthalate (DBP), one of endocrine disruptors, by γ-ray irradiation was enhanced by the effective energy conversion of γ-ray through the interaction with some kind of metal materials.
Noncatalytic Cannizzaro-type Reaction of Acetaldehyde in Supercritical Water
Authors: Nagai Yasuharu , Wakai Chihiro , Matubayasi Nobuyuki , Nakahara Masaru
Published: March 2003

In supercritical water at 400 °C and 0.5 g/cm3 (37 MPa), acetaldehyde was found to be transformed without catalysts into ethanol and acetic acid through a Cannizzaro-type disproportionation reaction. No aldol-type condensation products were detected, and the disproportionation competed with the decomposition into methane. Ethanol was generated in excess to acetic acid, and carbon dioxide appeared as a product only in the presence of supercritical water. This reaction behavior is explained by considering that carbon monoxide is provided by the acetaldehyde decomposition and leads to the formation of formic acid as a reducing intermediate for acetaldehyde.
Gender and role‐based perceptions of domestic abuse: does sexual orientation matter?
Authors: Seelau Eric P. , Seelau Sheila M. , Poorman Paula B.
Published: March 2003

Although it is estimated that domestic abuse is as common in gay male and lesbian intimate relationships as in heterosexual relationships, the legal system often fails to recognize or respond to same‐gender cases. Empirical research examining the impact of sexual orientation on perceptions of abuse is virtually nonexistent. Undergraduates (N = 252) read a summary of a domestic abuse incident in which victims and perpetrators varied by gender and, by implication, sexual orientation. Victim and respondent gender, rather than the couple's sexual orientation, primarily affected responses to domestic abuse. Domestic abuse perpetrated against women was perceived to be more serious and in need of intervention than abuse against men. Women were more likely than men to believe the victim and to recommend criminal justice system interventions. Because they are inconsistent with gender role stereotypes, domestic abuse cases involving male victims or female perpetrators may not receive equitable treatment within the criminal justice system. Copyright © 2003 John Wiley & Sons, Ltd.
Narrative plausibility: the impact of sequence and anchoring
Authors: Canter David V. , Grieve Nicola , Nicol Catherine , Benneworth Kelly
Published: March 2003

The perceived plausibility of suspect narratives is hypothesized to be a product of more than logical evaluation. Aspects of the narrative's internal structure, notably the extent to which it follows a canonical (or stereotypical) sequence of events, may influence judged plausibility. Plausibility may also be sensitive to external “anchors” that activate relevant schema. To test these possibilities, variations of two suspect testimonies were created in accordance with the model by Stein and Glenn (1979) of a stereotypical story grammar, and the account by Wagenaar, van Koppen, and Crombag (1993) of narrative anchoring. Subjects rated the narrative account using a perceived plausibility scale developed from pilot work. ANOVA revealed that criminal anchoring in suspect statements, regardless of the crime scenario, has a negative effect on the plausibility level. Similarly, plausibility levels were lower when the statement did not follow a temporal sequence of events. The implications for models of how people judge plausibility are discussed, as are the practical implications for legal contexts. Copyright © 2003 John Wiley & Sons, Ltd.
Regulation of FLRG expression in rat primary astroglial cells and injured brain tissue by transforming growth factor‐β1 (TGF‐β1)
Authors: Zhang G. , Ohsawa Y. , Kametaka S. , Shibata M. , Waguri S. , Uchiyama Y.
Published: March 2003

Follistatin‐related gene (FLRG) is a member of the follistatin family of proteins and interacts with transforming growth factor (TGF) superfamily proteins like follistatin. To understand the expression level of FLRG in brain tissue, we examined whether primary neurons and glial cells from rat embryos express FLRG mRNA and produce its protein product. FLRG and follistain mRNAs were mainly expressed in astroglial cells, while activin A mRNA was abundant in primary neurons. TGF‐β1 highly enhanced expression levels of FLRG mRNA in astroglial cells, compared with those of follistatin and activin A mRNAs. Particularly, TGF‐β1 facilitated the secretion of FLRG protein from primary astroglial cells in a dose‐dependent manner. Moreover, changes in expression levels of FLRG mRNA and protein in brain tissue were also analyzed after a penetrating injury, using quantitative polymerase chain reactin (PCR) and immunohistochemical methods. Expression levels of FLRG mRNA were significantly increased in damaged regions after penetrating injury together with those of activin A and TGF‐β1 mRNAs. Immunohistochemical observations showed that positive signals of FLRG protein were colocalized in glial fibrillary acidic protein‐positive reactive astroglial cells located in damaged regions after a penetrating injury. The expression of follistatin mRNA rather decreased in damage regions after the brain injury. These results suggest that FLRG is synthesized in and secreted from astroglial cells. In particular, FLRG, but not follistatin, may play a role in the regulation of activin A in brain wound healing in response to TGF‐β1. © 2003 Wiley‐Liss, Inc.
Closed Loop Recycling of Bottle Crates Using the Restabilization Technique
Authors: Kartalis C. N. , Papaspyrides C. D. , Pfaendner R. , Hoffmann K. , Herbst H.
Published: March 2003

A remelting‐restabilization technique was applied for the recycling of post‐used, yellow pigmented high density polyethylene (HDPE) bottle crates. In order to evaluate the potential of the recyclate to be used in the original application, the most important parameters were investigated: processing stability, long‐term heat stability and light stability. A multiple extrusion cycles procedure at different reprocessing temperatures was performed for monitoring the processing stability of the restabilized and non‐restabilized material. Oven aging was applied for about 8 800 h (i.e., more than one year) to evaluate the long term thermal stability of the crate material, as manifested by melt flow rate, tensile impact strength, and time until embrittlement measurements. To evaluate the light stability of the recycled material artificial weathering was applied for about 8 000 h, whereas the tensile impact strength was monitored. The latter data were enriched with microphotographs of the specimens surface. Finally, repigmentation was used to investigate the role of new pigments on the final performance of the recycled product. The results illustrate that restabilization is mandatory for the quality improvement of post‐used crates ensuring its re‐use in the original application and thus making closed loop recycling possible.

Autoxidation cycle of polymeric materials.

magnified image

Autoxidation cycle of polymeric materials.
Temperature and pH‐Dependent Swelling Behavior of Poly(N‐isopropylacrylamide) Copolymer Hydrogels and Their Use in Flow Control
Authors: Kuckling Dirk , Richter Andreas , Arndt Karl‐Friedrich
Published: March 2003

Poly(N‐isopropylacrylamide) (PNIPAAm) copolymer gels with acidic and basic comonomers of various molar ratios were prepared by radical polymerization. The relationship between the swelling behavior of the gels and the copolymerization ratio was studied experimentally at different temperatures and in various pH value buffer solutions. The results of the experiments revealed that the transition temperatures of the PNIPAAm copolymer gels were changed in proportion to the monomer ratio used in copolymerization. The pH value of the buffer solution strongly affected the swelling ratio and some of the transition temperatures of the gels. The PNIPAAm copolymer gels were used in a chemo‐mechanical valve. The liquid flows directly through a gel actuator, which consists of a cylindrical actuator chamber filled with small particles of the sensitive cross‐linked polymer. The flow rate as well as the pressure drop was measured in dependence on the solvent properties. With the presented experimental arrangement it could be shown that sensitive polymers can be used for controlling the flow in dependence on temperature and pH.

pH‐Dependence of the pressure in a chemo‐mechanical valve.

magnified image

pH‐Dependence of the pressure in a chemo‐mechanical valve.
Identification of pheromones and optimization of bait composition for click beetle pests (Coleoptera: Elateridae) in Central and Western Europe
Authors: Tóth Miklós , Furlan Lorenzo , Yatsynin Venyamin G , Ujváry István , Szarukán István , Imrei Zoltán , Tolasch Till , Francke Wittko , Jossi Werner
Published: March 2003

Based on analysis of pheromone gland extracts, highly attractive new baits have been developed for three click beetle pests. That for Agriotes brevis is a mixture of geranyl butanoate and (E,E)‐farnesyl butanoate, and that for A rufipalpis and A sordidus contains geranyl hexanoate alone. From known data from species populating Russia, optimized bait compositions for species in Central and Western Europe were developed as follows: geranyl octanoate + geranyl butanoate for A lineatus, geranyl isovalerate for A litigiosus, geranyl hexanoate + geranyl octanoate for A obscurus, geranyl butanoate alone for A sputator and (E,E)‐farnesyl acetate alone for A ustulatus. Although slight differences were found in gland contents with A litigiosus var laichartingi and fenotypus typicus, nevertheless there were no differences in response to the optimum bait. There were no differences in pheromone composition or response to the optimized bait between the two morphological forms (‘black’ and ‘red’) of A ustulatus. As a result of these studies, highly effective pheromone baits are now available for monitoring and population reduction in all important pest click beetle species in Central and Western Europe.

© 2003 Society of Chemical Industry
Role of reactive oxygen species and antioxidants in plant disease resistance
Authors: Barna Balázs , Fodor József , Pogány Miklós , Király Zoltán
Published: March 2003

Membrane damage caused by the non‐specific fungal toxin fusaric acid was less on pre‐treated than on control leaves when tobacco leaves were pretreated with anti‐senescence plant hormones, such as kinetin, benzyladenine or the anti‐ozonant N‐[2‐(2‐oxo‐1‐imidazolidinyl)]ethyl‐N′‐phenylurea. Similarly, the necrosis caused by mercuric chloride was reduced by the above anti‐senescence agents. In addition, in in vitro tests, leaves from selected paraquat‐tolerant tobacco plants were less sensitive to Alternaria alternata (Fr) Keissler infection than those of the control paraquat‐sensitive tobacco leaves. Paraquat‐tolerant Conyza canadensis (L) Cronq weeds naturally selected in vineyards in Hungary showed similar inhibition of senescence to paraquat‐tolerant tobacco, expressed as more green leaves and slower development. In accordance with this, the paraquat‐tolerant Conyza leaves remained almost symptomless, while paraquat‐sensitive plants showed severe symptoms after infection with Botrytis cinerea Pers. Oxidative burst (accumulation of hydrogen peroxide) was attenuated in TMV‐infected leaves of Xanthi‐nc tobacco as a result of treatment with salicylic acid or in leaves where systemic acquired resistance (SAR) had been induced by a previous TMV infection. Accordingly, superoxide dismutase (SOD) activity was higher in Xanthi tobacco leaves with SAR than without SAR. However, in NahG tobacco, in which SAR cannot develop, there was no augmentation of SOD activity. All the above data support the significance of delayed senescence and antioxidants in the resistance of plants to biotic and abiotic necrosis‐inducing agents.

© 2003 Society of Chemical Industry
Effect of Polysaccharide Krestin on the Up-regulation of Macrophage Colony-Stimulating Factor Gene Expression in Protecting Mouse Peritoneal Macrophages from Oxidative Injury
Authors: Pang Zhan-Jun
Published: March 2003

Oxidative injury caused by oxidatively modified low density lipoprotein (Ox-LDL) plays an important role in the transformation of macrophages into foam cells and atherogenesis. Treatments to protect macrophages from oxidative injury will be effective in treating atherosclerosis. A macrophage-specific growth factor, macrophage colony-stimulating factor (M-CSF), was reported to be able to prevent the progression of atherosclerosis in Watanabe heritable hypercholesterolemic (WHHL) rabbits. A protein-bound polysaccharide, polysaccharide Krestin (PSK), was also proven to have effects in preventing atherosclerosis in our previous work. We proposed that, both M-CSF and PSK could protect macrophages from oxidative injury, and the effects of PSK were associated with its capability of inducing M-CSF expression. In our present results, M-CSF could alleviate the Ox-LDL- or tert-butyl hydroperoxide (tbOOH)-induced injury to mouse peritoneal macrophages, and PSK exhibited some similar effects. PSK treatment could induce M-CSF gene expression and secretion in mouse peritoneal macrophages. Furthermore, actinomycin D and cycloheximide could attenuate that induction. We concluded that, maybe PSK exerted its effects on macrophages partly through the transcriptional induction of M-CSF in the cells.
PRÜFER ⋆-MULTIPLICATION DOMAINS AND SEMISTAR OPERATIONS
Authors: FONTANA M. , JARA P. , SANTOS E.
Published: March 2003

Starting from the notion of semistar operation, introduced in 1994 by Okabe and Matsuda [49], which generalizes the classical concept of star operation (cf. Gilmer's book [27]) and, hence, the related classical theory of ideal systems based on the works by W. Krull, E. Noether, H. Prüfer, P. Lorenzen and P. Jaffard (cf. Halter–Koch's book [32]), in this paper we outline a general approach to the theory of Prüfer ⋆-multiplication domains (or P⋆MDs), where ⋆ is a semistar operation. This approach leads to relax the classical restriction on the base domain, which is not necessarily integrally closed in the semistar case, and to determine a semistar invariant character for this important class of multiplicative domains (cf. also J. M. García, P. Jara and E. Santos [25]). We give a characterization theorem of these domains in terms of Kronecker function rings and Nagata rings associated naturally to the given semistar operation, generalizing previous results by J. Arnold and J. Brewer ]10] and B. G. Kang [39]. We prove a characterization of a P⋆MD, when ⋆ is a semistar operation, in terms of polynomials (by using the classical characterization of Prüfer domains, in terms of polynomials given by R. Gilmer and J. Hoffman [28], as a model), extending a result proved in the star case by E. Houston, S. J. Malik and J. Mott [36]. We also deal with the preservation of the P⋆MD property by ascent and descent in case of field extensions. In this context, we generalize to the P⋆MD case some classical results concerning Prüfer domains and PvMDs. In particular, we reobtain as a particular case a result due to H. Prüfer [51] and W. Krull [41] (cf. also F. Lucius [43] and F. Halter-Koch [34]). Finally, we develop several examples and applications when ⋆ is a (semi)star given explicitly (e.g. we consider the case of the standardv-, t-, b-, w-operations or the case of semistar operations associated to appropriate families of overrings).