bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake of glutamate is impaired in the cortical penumbra of the rat following middle cerebral artery occlusion: An in vivo microdialysis extraction study
Authors: Bruhn Torben , Christensen Thomas , Diemer Nils Henrik
Published: January 2003

By using microdialysis extraction of 3H‐D‐aspartate and concomitant recordings of extracellular direct current (DC) potentials, the effect of middle cerebral artery occlusion (MCAO) was studied continuously over a period of 100 min in the cerebral cortex of rats. From analysis of the DC potentials, rats subjected to MCAO could be divided into three groups, one in which the dialysis probe was located in the ischemic core, one in which the probe was in the penumbra, and one in which the probe was in nonischemic tissue. In general, extraction of 3H‐D‐aspartate was positively correlated with the DC potential; i.e., changes in the extraction were concurrent with changes in the DC potential. Comparing the different animal groups by integration of all extraction values obtained during MCAO over time, 3H‐D‐aspartate extraction was reduced by 40% in the penumbra, and by 58% in the ischemic core, compared with the sham‐operated controls. No changes was found in the nonischemic group. In the penumbra group, extraction of 3H‐D‐aspartate was reduced initially upon institution of MCAO but recovered to control‐like levels over a period of 15–40 min, despite ongoing MCAO. In addition, extraction was reduced transiently during periinfarct depolarizations. A mean of all extraction values obtained during MCAO in the penumbra group was reduced by 47% compared with a mean of values obtained before institution of MCAO. Induction of death resulted in a reduction of 3H‐D‐aspartate extraction by 86%. The present results provide direct evidence that uptake of Glu is reduced both in the ischemic core and in the penumbra of the cerebral cortex following MCAO in rats, possibly contributing to the initiation and spread of infarction. The results further indicate that uptake of Glu in the penumbra recovers to control‐like levels, despite ongoing MCAO, providing evidence that Glu uptake by the Glu transporter proteins is reinstituted and/or up‐regulated. © 2002 Wiley‐Liss, Inc.
Inhibition of long‐term potentiation by interleukin‐8: Implications for human immunodeficiency virus‐1‐associated dementia
Authors: Xiong Huangui , Boyle Jeffery , Winkelbauer Matthew , Gorantla Santhi , Zheng Jialin , Ghorpade Anuja , Persidsky Yuri , Carlson Kimberly A. , Gendelman Howard E.
Published: January 2003

Human immunodeficiency virus type 1 (HIV‐1)‐infected mononuclear phagocytes (MP; brain macrophages and microglia) secrete a number of toxic factors that affect the pathogenesis of HIV‐1‐associated dementia (HAD). The identification and relative role of each MP toxin for neuronal dysfunction during HAD are not well understood. Interleukin‐8 (IL‐8), a CXC chemokine involved in leukocyte activation and chemotaxis, is constitutively produced by MP, and elevated levels of IL‐8 mRNA were detected in the brains of patients with HIV‐1 encephalitis (HIVE) by both ribonuclease protection assays and real‐time PCR. To determine the role that IL‐8 might play in the neuronal dysfunction in HAD, we studied its effect on synaptic transmission and plasticity in the CA1 region of hippocampus, the seat of learning and memory. Bath application of IL‐8 (50 ng/ml) to rat hippocampal slices had no effect on basal synaptic transmission. However, IL‐8 was shown to inhibit long‐term potentiation (LTP) in a concentration‐dependent manner. In control and IL‐8‐treated slices, the LTP magnitudes were 167.8% ± 11.9% (mean ± SE; n = 17) and 122.2% ± 16.2% of basal levels (n = 13), respectively. These differences were statistically significant (P < 0.05). Preincubation of hippocampal slices with a monoclonal CXCR2 antibody (2 μg/ml) but not control IgG (2 μg/ml) blocked IL‐8‐induced inhibition of LTP. The expression of CXCR2 receptors in the CA1 region was shown by Western blot assays. The induction of IL‐8 in HAD, its inhibition of LTP, and the expression of its receptor, CXCR2, in the hippocampus all suggest that it plays a role in the cognitive dysfunction associated with HAD. © 2002 Wiley‐Liss, Inc.
Opposite effects of α1‐ and β‐adrenoceptor stimulation on both glutamate‐ and γ‐aminobutyric acid‐mediated spontaneous transmission in cultured rat hippocampal neurons
Authors: Croce Ariane , Astier Hélène , Récasens Max , Vignes Michel
Published: January 2003

The effects of adrenergic receptor stimulation on spontaneous synaptic transmission were investigated in cultured rat hippocampal neurons by recording spontaneous excitatory and inhibitory postsynaptic currents (sEPSC and sIPSC). Noradrenaline (NA) inhibited sEPSC in a concentration‐dependent manner, with maximal effect at 10 μM. The α1‐ and α2‐adrenoceptor‐selective agonists cirazoline and clonidine induced an inhibition of sEPSC appearance, whereas the β‐adrenoceptor agonist isoproterenol elicited an increase. The inhibitory effect of NA was reversed by α1‐adrenoceptor blockade. The participation of γ‐aminobutyric acid (GABA)B‐receptor stimulation in the inhibitory effect of NA was further examined. GABAB‐receptor stimulation with baclofen induced a strong inhibition of bursting activity, which was fully reversed by the GABAB antagonist CGP 55845. By itself, CGP 55845 exerted a stimulatory effect on sEPSC frequency. In the presence of CGP 55845, the inhibitory effects of cirazoline and clonidine were maintained. NA (1, 10, and 100 μM) and α‐adrenoceptor agonists decreased miniature EPSC and IPSC occurrence, whereas β‐adrenergic stimulation increased it. In 50% of the cells examined, NA (1, 10 μM) had a stimulatory effect on sIPSC, whereas, in the remaining 50% of cells, NA (1, 10 μM) had an inhibitory effect. In all the cells, 100 μM NA induced an inhibition of sIPSC. The inhibitory effect of NA was due to α1‐receptor stimulation, whereas the excitatory effect was due to β‐receptor stimulation. In cultured hippocampal neurons, spontaneous excitatory and inhibitory synaptic transmissions are both similarly altered by adrenoceptor stimulation. However, in a subset of cells, low concentrations of NA mediate an increase of sIPSC via β‐adrenoceptor activation. © 2002 Wiley‐Liss, Inc.
Representing identities through tourism: encounters of ethnic minorities in Dali, Yunnan Province, People's Republic of China
Authors: Doorne S. , Ateljevic I. , Bai Z.
Published: January 2003

In the current era of globalisation ȧand regional economic integration, localised concerns with cultural identity, historical memory and collective belonging are assuming a new significance. Rather than signalling the end of localised identities, however, the current period has infused processes of identity formation with elements of political economy. One central component of political economy through which these processes are being expressed is tourism. In this context, as the social sciences have begun to take tourism seriously when addressing broader issues of culture and society, this paper elaborates on new arenas through which processes of identity formation are being articulated.
Drawing on a current research project focused on cultural tourism in Dali, Yunnan Province, China, the discussion emphasises the extent to which cultural identities are appropriated, constructed and traded through and around material objects of touristic exchange. Copyright © 2003 John Wiley & Sons, Ltd.
Services and functions provided by European city tourist offices: a longitudinal study
Authors: Wöber Karl W. , Hwang Yeong‐Hyeon , Fesenmaier Daniel R.
Published: January 2003

Tourism has become a major source of employment, revenue, international awareness and opportunity in European cities. As competition among European cities grows, the efficiency of management in city tourism organisations (CTOs) becomes increasingly important. This article reports on a longitudinal study of 50 European CTOs over the 4‐year period from 1995 to 1999. The aim of the study is to examine the changes in functions provided by European CTOs during the given period of time. Findings reveal that five identifiable function categories can characterise the changes that happened during the given period of time: hotel booking service, commerce, conventional information dissemination, advanced information product and relationship management. It is argued that information technology and role change are the main driving forces of these changes. Copyright © 2003 John Wiley & Sons, Ltd.
A comparison of training activities in the Austrian and German accommodation trade using the TrainingActivityDegree
Authors: Langer G.
Published: January 2003

This article introduces the TrainingActivityDegree (TAD), a new method for the quantitative measurement of training activities, by presenting the empirical results from a practical application in which the training activities in the Austrian and German accommodation trade were compared. In the accommodation trade survey, a clear need for a method for acquiring reliable data of training activities in a fragmented branch such as the accommodation trade arose. Consequently the TAD index was developed. The practical application within an exploratory survey demonstrates its suitability for acquiring and comparing training participation, not only in the Austrian and German accommodation trade. Copyright © 2003 John Wiley & Sons, Ltd.
Testing a cultural tourism typology
Authors: McKercher Bob , du Cros Hilary
Published: January 2003

This paper tests further a cultural tourism typology based on the interface between centrality of cultural tourism as a trip motive and the depth of experience. Five types of cultural tourist are identified that represent five benefit‐based segments. The segments are tested against a variety of trip, demographic, motivational, preferred activity, awareness, cultural distance and activity variables. Significant differences are noted between the groups, suggesting that the model presented may be effective in segmenting the cultural tourism market. Moreover, although the segmentation process is predicated on two variables, these variables are reflective of underlying trip motivation, activity preference and cultural distance factors noted between the different types of cultural tourist. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of sodium selenite on lipids and lipid‐metabolizing enzymes in N‐nitrosodiethylamine‐induced hepatoma‐bearing rats
Authors: Thirunavukkarasu C. , Selvedhiran K. , Prince Vijaya Singh J. , Senthilnathan P. , Sakthisekaran D.
Published: January 2003

As part of a substantial effort to curtail the adverse health effects posed by hepatoma, studies have been conducted to elucidate the possible mechanism for the anticarcinogenic action of sodium selenite against N‐nitrosodiethylamine‐induced hepatoma. Several investigations recognize selenium as potent antioxidant, as well as an anticarcinogen, in both animal and human systems. Sodium selenite was administered to Wistar rats bearing hepatoma induced by N‐nitrosodiethylamine to study the alterations in the concentration of lipid profiles and in activities of some lipid‐metabolizing enzymes. Control and tumor‐bearing animals were fed 4 ppm of sodium selenite before initiation or during initiation and/or during promotion phases of carcinogenesis. Hepatic total cholesterol, free cholesterol, triglycerides, free fatty acids, and phospholipids were significantly lowered, whereas cholesterol esters was greater because of selenite administration in N‐nitrosodiethylamine‐induced tumor‐bearing rats. Total lipase, lipoprotein lipase, lecithin: cholesterol acyl transferase, and cholesterol ester synthetase registered greater activities in hepatoma of selenite administered rats with tumor whereas the activity of cholesterol ester hydrolase in hepatoma‐bearing animals was lower as a result of selenite administration. These observations clearly indicate the effect of selenite in correcting the abnormalities of lipid metabolism in tumor‐induced animals. Previous evidence from this laboratory and present observations it can be concluded that the anticancer property of selenite my also be by its strong hypolipidemic capacity in vivo system. J. Trace Elem. Exp. Med. 16:1–15, 2003. © 2003 Wiley‐Liss, Inc.
High dietary fructose compared with corn starch does not heighten changes in copper absorption, retention, or status indicators in men fed low dietary copper
Authors: Milne David B. , Nielsen Forrest H.
Published: January 2003

In experimental animals, high dietary fructose exacerbates signs of copper deficiency in rats. Thus, an experiment was performed to determine whether high dietary fructose affected copper metabolism and copper status indicators in healthy men who were fed low dietary copper. Six men aged 27 to 37 years completed a metabolic unit study divided into four 7‐week dietary periods with a randomized, double‐blind, 2 × 2 factorial design with variables of 0.6 or 2.6 mg Cu/2500 kcal and fructose or corn starch as 20% of energy. Twice during each dietary period the men consumed a standardized breakfast meal labeled with 2.5 μCi 67Cu, then were counted daily in a whole‐body counter for 3 weeks after each meal. At the end of each dietary period, blood was collected to assess copper status. Neither type of dietary carbohydrate nor intake of copper significantly affected 67Cu absorption, but copper deprivation resulted in a negative copper balance. The source of dietary carbohydrate did not affect the biological half‐life of copper, but it was significantly (P < 0.001) longer when dietary copper was low (35 ± 11 d; mean ± SD) than when supplemented (20 ± 5 days). The natural log of the biological half‐life directly correlated with plasma copper (r = 0.498; P = 0.001) and immunoreactive, or radial immunodiffusion, ceruloplasmin (RID Cp; r = 0.394; P = 0.013), and was inversely related to glutathione (r = −0.510, P = 0.03). When high dietary fructose was fed, erythrocyte superoxide dismutase activity and RID Cp was lower, and the enzymatic ceruloplasmin/RID Cp ratio was higher during copper depletion than during repletion; just the opposite occurred when corn starch was fed. No other copper status indicator was affected by an interaction between dietary carbohydrate and copper or was heightened by high dietary fructose. The results indicate that men fed approximately 0.6 mg Cu/d for 7 weeks attempted to adapt to this low intake by retaining absorbed copper longer. The adaptation was inadequate because copper balance became negative. However, although copper status was decreased, the response of men to short‐term dietary copper deprivation was not heightened by high dietary fructose. J. Trace Elem. Exp. Med. 16:27–38, 2003. © 2003 Wiley‐Liss, Inc.
Side effects of lithium on rat cranial arachnoid and dura mater collagen: A quantitative ultrastructural study
Authors: Tzaphlidou Margaret
Published: January 2003

Lithium is widely used in medicine as an antidepressive drug. Despite abundant literature on the subject, questions on the effects of lithium on collagen, which is one of the major components of tissues and organs, are far from being answered. We have examined the effects of lithium chloride (1.5 meq/kg of body weight) on rat cranial arachnoid and dura mater collagen fibrils by electron microscopy and image analysis. Animals were sacrificed 1 day, 2, 6, and 12 months after the end of a 30‐consecutive days experimental period. In all cases investigated, severe structural abnormalities in collagen fibrils, at the ultrastructural level, were found. These abnormalities consist of decreased mean diameter and irregularity of shape of collagen fibrils (when viewed in cross sections) as well as marked disorganization in the packing of the fibrils. The observed alterations seem to be permanent. J. Trace Elem. Exp. Med. 16:17–26, 2003. © 2003 Wiley‐Liss, Inc.
Experimental stress‐induced changes in trace element levels of various tissues in rats
Authors: Karakoc Yunus , Yurdakos Ertan , Gulyasar Tevfik , Mengi Murat , Barutcu U. Bora
Published: January 2003

In this study, we investigated the effects of acute and chronic immobilization stress on the Zn, Cu, and Fe levels of the temporal lobe, brain stem, spleen, and liver tissues in rats. The animals in the acute stress group were put in the cages, one time only for 120 min. For the chronic stress groups (2h and 4h), the rats were kept in the cages daily for 2 and 4 h, respectively, for 5 consecutive days. Controls and immobilized rats were decapitated, and then tissue samples were taken. Zn, Cu, and Fe levels in the temporal lobe, brain stem, spleen, and liver were measured by flame atomic absorption spectrophotometer. Our results showed that acute immobilization stress causes endogenous Zn and Cu release from the brain tissues. In the 2h chronic stress group, Fe levels markedly increase in the temporal lobe and brain stem whereas they decrease in the spleen and liver. In the 4h chronic stress group, Fe levels increase in the temporal lobe and brain stem while Zn and Cu levels increase in the spleen and liver. In the acute and chronic immobilization stress groups, mobilization of Zn and Cu can be related to the induction of metallothionein (MT) in the liver and spleen but not in the brain. On the other hand, excess Fe in the temporal lobe and brain stem causes us to believe think that the brain iron transport proteins may be involved, and enhanced, by immobilization stress. J. Trace Elem. Exp. Med. 16:55–60, 2003. © 2003 Wiley‐Liss, Inc.
Enhanced tolerance to high cytostatic doses by means of oligoelements Mn, Se, and Zn plus Lachesis muta venom: In vivo and in vitro studies
Authors: Crescenti Ernesto J. , Croci Máximo , Rivera Elena , Bergoc Rosa M.
Published: January 2003

We evaluated, in vivo and in vitro, the increased tolerance to treatment with high doses of chemotherapeutic drugs produced by the administration of oligoelements (Zn, Se, Mn) plus Lachesis muta venom (O‐LM). Cyclophosphamide, methotrexate, and 5‐fluoruracil (CMF) were administrated to male rats treated daily with O‐LM. The doses of CMF tested covered from 1‐ to 20‐fold the dose used in human patients. Human neoplastic and normal cell lines were challenged in vitro with increasing doses of 5‐fluoruracil (5‐FU) in the presence and absence of O‐LM. Results indicated a significantly higher global survival in O‐LM‐treated rats versus Control rats. LD50 in O‐LM rats was 18.5‐fold the basic CMF dose versus 14.1 in controls. Eighty percent of Control rats showed severe bone marrow aplasia, sepsis, and secondary leukemia, while only 20% of O‐LM‐treated rats showed these effects and no leukemia cases were observed. O‐LM treatment produced a significant inhibition of cell proliferation of malignant cells, while in normal cells O‐LM increased colony formation. In transformed cells, the cytostatic effect of 5‐FU was significantly enhanced by O‐LM pre‐treatment, in contrast with the protective effect exerted on normal cells. Toxicological studies clearly demonstrated that O‐LM did not produce any toxic or undesirable effect when administered to normal animals. Whole body weight, water and food consumption, and laboratory parameters remained unchanged after O‐LM administration, even with a dose 10‐fold higher than that employed in the experimental work. Results obtained afford the possibility of applying this protective treatment to human patients undergoing high‐dose chemotherapy. J. Trace Elem. Exp. Med. 16:39–53, 2003. © 2003 Wiley‐Liss, Inc.
Contextual constraints in knowledge management theory: the cultural embeddedness of Nonaka's knowledge‐creating company
Authors: Glisby Martin , Holden Nigel
Published: January 2003

Nonaka and Takeuchi's book The Knowledge Creating Company is one of the most influential in the field of knowledge management. The famous SECI Model, representing the four modes of knowledge creation (socialization, externalization, combination and internalization) seems to have been accepted by the knowledge management community as universally valid in conception and in application. This paper argues that the model must be seen first and foremost as a product of the environment from which it emerged, namely Japan. It is contended that each of the four modes can only be understood with reference to their embeddedness in Japanese social and organizational culture and related value systems. Thus the model should be used with caution. It should be seen as a map rather than a model; or perhaps as a special kind of mirror, which allows us to see ourselves and our knowledge management practices in new ways for directing change. Copyright © 2003 John Wiley & Sons, Ltd.
Us not them! Impeding knowledge management in supply chains
Authors: Kidd John
Published: January 2003

For many years following the Industrial Revolution there was a period of stability where knowledge of processes could be assimilated at a slow pace by new generations of workers: one ploughed the fields, set the seeds, and in due course gathered in the crops. Father taught son, and so life rolled on. This is not so nowadays, capital equipment is much larger and more expensive so it has to be kept working day and (often) at night, and to raise efficiency there are satellite guidance systems (GPS) to locate exactly where in the fields to administer changes in fertilizer regimes following soil and yield assessment. Statistical analyses and data management have become a dominant factor in modern farm management—as has maintaining awareness of global events and regional legislation with respect to production limits and quota systems. In other words, the pace of life has quickened, and knowledge management has become a real need. The acquisition of data has to be fast, and its exchange between workers has to be open to develop an awareness of interlinks between all the pertinent data. We know the world is not ‘ideal’, so in this paper we will look to the factors that might inhibit knowledge transfer, thus delay or deny learning. Further, as each enterprise is but one in a complex web of ‘supply chains’, we will note macro factors that may inhibit better micro performance in multinational companies as they attempt to pursue their global business and exchange their knowledge. Copyright © 2003 John Wiley & Sons, Ltd.
Outsourcing best practice: transformational and transactional considerations
Authors: Kakabadse Andrew , Kakabadse Nada
Published: January 2003

This paper argues that outsourcing is a powerful strategic lever, which if effectively utilized by senior management can significantly differentiate the host organization from its competitors. As outsourcing is recognized as a more critical boardroom issue, it is considered that the nature of best practice outsourcing requires examination. A review of the literature highlights particular perspectives concerning outsourcing best practice. Further, the results of a Cranfield School of Management survey emphasize critical transformational and transactional considerations in pursuing best practice application. It is concluded that senior management holding a shared view concerning the strategic advantage outsourcing can provide and them attending to the details of the host organization/supplier contract, is the basis to outsourcing best practice. Copyright © 2003 John Wiley & Sons, Ltd.
Issues on knowledge coordination
Authors: da Silva Flávio Soares Corrêa , Agustí‐Cullel Jaume
Published: January 2003

In the present work we argue thatcoordinationis a key factor for managing knowledge within organisations. Given the classification of organizational principles suggested by C. I. Barnard in the 1930s, based on the proposition that persons in an organization should be regarded either as ‘objects to be manipulated’ or as ‘subjects to be satisfied’ (we identify these principles respectively asstructure‐centricandpeople‐centricorganizational principles), we show how this classification encompasses every management model proposed from Taylor's Scientitic Administration to the most recent ones. We also show how the same principles have been rediscovered recently within the context of knowledge management. Although structure‐centric organizational principles have been regarded as outdated in many situations nowadays, they have received more attention from information technology researchers than people‐centric ones. We analyse this fact from a conceptual viewpoint, identifying the potentialities and advantages of each of these principles, as well as their pitfalls and restrictions. The main conceptual tool for structure‐centric knowledge management areartificial ontologies. Since we have not identified any predominant tool to pair up with artificial ontologies on the side of people‐centric knowledge management, we propose one such tool, which we believe that can be the main contribution of the present work. The conceptual tool we propose is calledstructures of capability providers, for reasons that will become clear when it is presented. The article aims at providing an encompassing view of knowledge coordination, based on the principles above. We are particularly careful to show that much of what has been discussed and used today for knowledge management has been around for at least 60 years. Copyright © 2003 John Wiley & Sons, Ltd.
Application of knowledge management technology in customer relationship management
Authors: Bose Ranjit , Sugumaran Vijayan
Published: January 2003

Given the important role being played by knowledge management (KM) systems in the current customer‐centric business environment, there is a lack of a simple and overall framework to integrate the traditional customer relationship management (CRM) functionalities with the management and application of the customer‐related knowledge, particularly in the context of marketing decisions. While KM systems manage an organization's knowledge through the process of creating, structuring, disseminating and applying knowledge to enhance organizational performance and create value, traditional CRM have focused on the transactional exchanges to manage customer interactions. True CRM is possible only by integrating them with KM systems to create knowledge‐enabled CRM processes that allow companies to evaluate key business measures such as customer satisfaction, customer profitability, or customer loyalty to support their business decisions. Such systems will help marketers address customer needs based on what the marketers know about their customers, rather than on a mass generalization of the characteristics of customers. We address this issue in this paper by proposing an integrated framework for CRM through the application of knowledge management technology. The framework can be the basis for enhancing CRM development. Copyright © 2003 John Wiley & Sons, Ltd.
Sperner spaces and first‐order logic
Authors: Blass Andreas , Pambuccian Victor
Published: January 2003

We study the class of Sperner spaces, a generalized version of affine spaces, as defined in the language of pointline incidence and line parallelity. We show that, although the class of Sperner spaces is a pseudo‐elementary class, it is not elementary nor even ℒ︁∞ω‐axiomatizable. We also axiomatize the first‐order theory of this class.
The equality S1 = D = R
Authors: Grossberg Rami , Kolesnikov Alexei , Tomašić Ivan , Van Dieren Monica
Published: January 2003

The new result of this paper is that for θ(x; a)‐stable (a weakening of “T is stable”) we have S1[θ(x; a)] = D[θ(x; a), L, ∞]. S1 is Hrushovski's rank. This is an improvement of a result of Kim and Pillay, who for simple theories under the (strong) assumption that either of the ranks be finite obtained the same identity. Only the first equality is new, the second equality is a result of Shelah from the seventies. We derive it by studying localizations of several rank functions, we get the following

Main Theorem. Suppose that μ is regular satisfying μ ≥ |T|+, p is a finite type, and Δ is a set of formulas closed under Boolean operations. If either (a) R[p, Δ, μ+] < ∞ or (b) p is Δ‐stable and μ satisfies “for every sequence {μi : i < |Δ| + ℵ0} of cardinals μi < μ we have that $ \prod _{i < \vert \Delta \vert + \aleph _{0}} \mu _{i} < \mu $ holds”, then S[p, Δ, μ+] = D[p, Δ, μ+] = R[p, Δ, μ+].

The S rank above is a localized version of Hrushovski's S1 rank. This rank, as well as our systematic use of local stability, allows us to get a more conceptual proof of the equality of D and R, which is an old result of Shelah. A particular (asymptotic) case of the theorem offers a new sufficient condition for the equality of S1 and D[·, L, ∞]. We also manage, due to a more general approach, to avoid some combinatorial difficulties present in Shelah's original exposition.
Topological aspects of numberings
Authors: Menzel Wolfram , Stephan Frank
Published: January 2003

We investigate connections between the syntactic and semantic distance of programs on an abstract, recursion theoretic level. For a certain rather restrictive notion of interdependency of the two kinds of distances, there remain only few and “unnatural” numberings allowing such close relationship. Weakening the requirements leads to the discovery of universal metrics such that for an arbitrary recursively enumerable family of functions a numbering compatible with such a metric can uniformly be constructed. We conclude our considerations with some implications on learning theory.
Consequences of neocompact quantifier elimination
Authors: Baratella Stefano , Ng Siu‐Ah
Published: January 2003

We provide some consequences of a Quantifier Elimination Property and related properties previously introduced (see [4]) in the setting of Banach space structures. We further consider some applications of quantifierfree definability, such as strict convexity via the definability of certain mapping and the continuity of definable functions.
A transfinite hierarchy of reals
Authors: Barmpalias George
Published: January 2003

We extend the hierarchy defined in [5] to cover all hyperarithmetical reals. An intuitive idea is used or the definition, but a characterization of the related classes is obtained. A hierarchy theorem and two fixed point theorems (concerning computations related to the hierarchy) are presented.
Making doughnuts of Cohen reals
Authors: Halbeisen Lorenz
Published: January 2003

For a ⊆ b ⊆ ω with b\ a infinite, the set D = {x ∈ [ω]ω : a ⊆ x ⊆ b} is called a doughnut. A set S ⊆ [ω]ω has the doughnut property 𝒟 if it contains or is disjoint from a doughnut. It is known that not every set S ⊆ [ω]ω has the doughnut property, but S has the doughnut property if it has the Baire property ℬ︁ or the Ramsey property ℛ. In this paper it is shown that a finite support iteration of length ω1 of Cohen forcing, starting from L, yields a model for CH + $ \sum ^1 _2 $(𝒟) + $ \neg \sum ^1 _2 $(ℬ︁) + $ \neg \sum ^1 _2 $(ℛ).
The failure of the axiom of choice implies unrest in the theory of Lindelöf metric spaces
Authors: Keremedis Kyriakos
Published: January 2003

In the realm of metric spaces the role of choice principles is investigated.
Classification of non‐well‐founded sets and an application
Authors: Takashi Nitta , Tomoko Okada , Tzouvaras Athanassios
Published: January 2003

A complete list of Finsler, Scott and Boffa sets whose transitive closures contain 1, 2 and 3 elements is given. An algorithm for deciding the identity of hereditarily finite Scott sets is presented. Anti‐well‐founded (awf) sets, i. e., non‐well‐founded sets whose all maximal ∈‐paths are circular, are studied. For example they form transitive inner models of ZFC minus foundation and empty set, and they include uncountably many hereditarily finite awf sets. A complete list of Finsler and Boffa awf sets with 2 and 3 elements in their transitive closure is given. Next the existence of infinite descending ∈‐sequences in Aczel universes is shown. Finally a theorem of Ballard and Hrbáček concerning nonstandard Boffa universes of sets is considerably extended.
Classical linear logics with mix separation principle
Authors: Kamide Norihiro
Published: January 2003

Variants of classical linear logics are presented based on the modal version of new structural rule !?mingle instead of the known rules !weakening and ?weakening. The cut‐elimination theorems, the completeness theorems (with respect to Girard's phase models) and a characteristic property named the mix separation principle are proved for these logics.
P ≠ NP for all infinite Boolean algebras
Authors: Prunescu Mihai
Published: January 2003

We prove that all infinite Boolean rings (algebras) have the property P ≠ NP according to the digital (binary) nondeterminism.
A note on the first incompleteness theorem
Authors: Ishii Katsumasa
Published: January 2003

Let T be an extension of Robinson's arithmetic Q. Then T is incomplete even if the set of the Gödel numbers of all axioms of T is ∑2.
On the problem of small motions and normal oscillations of a viscous fluid in a partially filled container
Authors: Azizov Tomas Ya. , Hardt Volker , Kopachevsky Nikolay D. , Mennicken Reinhard
Published: January 2003

The famous classical S. Krein problem of small motions and normal oscillations of a viscous fluid in a partially filled container is investigated by a new approach based on a recently developed theory of operator matrices with unbounded entries. The initial boundary value problem is reduced to a Cauchy problem

in some Hilbert space. The operator matrix 𝒜 is a maximal uniformly accretive operator which is selfadjoint in this space with respect to some indefinite metric. The theorem on strong solvability of the hydrodynamic problem is proved. Further, the spectrum of normal oscillations, basis properties of eigenfunctions and other questions are studied.
Anisotropic function spaces and related semi–linear hypoelliptic equations
Authors: Dachkovski Serguei
Published: January 2003

Looking for the best possible smoothness (in terms of the upper index of the Besov spaces) for the solution of some semi–linear equations we consider a model case of a hypoelliptic operator, which acts between anisotropic Besov spaces. To obtain the best regularity we need some properties for the corresponding spaces, which we prove here. In particular we prove Fatou, Fubini and truncation properties. We give also some characterisations of the Besov and Triebel–Lizorkin spaces.
Iterative solutions for zeros of accretive operators
Authors: Dominguez Benavides Tomas , Lopez Acedo Genaro , Xu Hong–Kun
Published: January 2003

Two iterative schemes are designed to approach zeros of m–accretive operators in Banach spaces. The first one is a kind of contractive iteration process involving with the resolvent and the second one is an averaged iteration process of the identity and the resolvent. Strong convergence for the first scheme and weak convergence for the second scheme are proved. The second scheme is also shown to have superlinear rate of convergence.
Infinite dimensional exponential attractors for a non–autonomous reaction–diffusion system
Authors: Efendiev Messoud , Miranville Alain , Zelik Sergey
Published: January 2003

In this article, we give a construction of exponential attractors that is valid for general translation–compact non–autonomous systems. Since they are generally infinite dimensional, we replace, compared with the standard definition, the condition of finite fractal dimensionality of exponential attractors by requiring that their epsilon–entropy have the same form as that of the uniform attractor. As an example, we prove the existence of an (infinite dimensional) exponential attractor for a reaction–diffusion system.
The cohomology of Banach space bundles over 1–convex manifolds is not always Hausdorff
Authors: Erat Matjaž
Published: January 2003

A holomorphic Hilbert space bundle E over ℙ1 is constructed such that H1(ℙ1, E) is not Hausdorff. Lifting this bundle to 𝒪 (–1) it is shown that such bundles exist also on non–compact 1–convex spaces.
Exact packing measure of linear Cantor sets
Authors: Feng De–Jun
Published: January 2003

Let K be the attractor of a linear iterated function system Sjx = ρjx +bj (j = 1, …, m) on the real line satisfying the open set condition (where the open set is an interval). It is well known that the packing dimension of K is equal to α, the unique positive solution y of the equation $ \sum _{j = 1} ^m \rho ^y _{j = 1} $; and the α–dimensional packing measure 𝒫α(K) is finite and positive. Denote by μ the unique self–similar measure for the IFS $ \{ S _j \} ^m _{j=1} $ with the probability weight $ \{ \rho ^\alpha _j \} ^m _{j=1} $. In this paper, we prove that 𝒫α(K) is equal to the reciprocal of the so–called “minimal centered density” of μ, and this yields an explicit formula of 𝒫α(K) in terms of the parameters ρj, bj (j = 1, …, m). Our result implies that 𝒫α(K) depends continuously on the parameters whenever $ \sum _j \rho_j < 1 $.
On the boundedness of the mapping f ↦ |f|μ, μ > 1 on Besov spaces
Authors: Kateb Djalil
Published: January 2003

Given μ > 1, 1 ≤ p≤¡∞, 1 ≤ q ≤ ∞, and 0 < s < μ + $ 1 \over p $, we show that the mapping Fμ : f ↦ |f|μ maps the Besov pace Bsp,q (ℝn) ∩ L∞(ℝn) on itself.
Weak*–closed Jordan ideals of nest algebras
Authors: Oliveira Lina
Published: January 2003

Nest algebras provide examples of partial Jordan *–triples. If A is a nest algebra and As = A ∩ A*, where A* is the set of the adjoints of the operators lying in A, then (A, As) forms a partial Jordan *–triple. Any weak*–closed ideal in the nest algebra A is also an ideal in the partial Jordan *–triple (A, As). An analysis of the ideal structure of (A, As) shows that, for a large class of nest algebras, the converse is also true.
On q–deformed hyponormal operators
Authors: Ôta Schôichi
Published: January 2003

The present paper deals with operators in a Hilbert space related to the theory of quantum groups. Some results on q–deformed hyponormal operators extend ones on q–normal operators. For a q–deformed operator T the Cartesian decomposition of the inverse T–1 is characterized and the product BT with bounded operator B is analyzed, and a q–analogue of the Fuglede–Putnam theorem is discussed.
Littlewood–Paley type inequality on ℝ
Authors: Quek Tong Seng
Published: January 2003

Let {Ik}k∈ℕ be a sequence of well–distributed mutually disjoint intervals of ℝ\{0}. For f ∈ Lp(ℝ), 1 ≤ p ≤ 2, define Sf by (Sf)ˆ = χ$\hat f $. We prove that there exists a positive constant C such that

for all f ∈ Lp(ℝ), 1 < p < 2, where 1/p + 1/p′ = 1 and ‖ · ‖p,p′ is the norm of the Lorentz space Lp,p′ (ℝ). An application of our result to Fourier multipliers is given.
Bordism of branched line bundles
Authors: Riegel Ulrich
Published: January 2003

We compute the bordism groups of branched line bundles and show that the bordism class of a branched line bundle is determined by characteristic numbers.
The effect of the variational framework on the spectral asymptotics for two–parameter nonlinear eigenvalue problems
Authors: Shibata Tetsutaro
Published: January 2003

We consider the nonlinear two–parameter problem

u″(x) + μu(x)p = λu(x)p,

u(x) > 0, x ∈ I = (0, 1),

u(0) = u(1) = 0,

where 1 < q < p < 2q + 3 and λ, μ > 0 are parameters. We establish the three–term spectral asymptotics for the eigencurve λ = λ(μ) as μ → ∞ by using a variational method on the general level set due to Zeidler. The first and second terms of λ(μ) do not depend on the relationship between p and q. However, the third term depends on the relationship between p and q, and the critical case is p = (3q – 1)/2.
Cesàro averaging operators
Authors: Stević Stevo
Published: January 2003

We define a family of Cesàro operators $ {\cal C} ^{\vec \gamma} $ on the polydisc Un, and consider the question of its boundedness on some spaces of analytic functions.
Nontrivial solutions for perturbed p–Laplacian on RN
Authors: Su Jiabao , Zhaoli Liu
Published: January 2003

In this paper, a positive and a negative solution are obtained for quasilinear elliptic equations on RN with resonance near infinity and near the origin at the first eigenvalue.
On the quotient of the representations of convexity and starlikeness
Authors: Tuneski Nikola
Published: January 2003

Let f(z) = z + a2z2 + … be an analytic function in the unit disk 𝒰 = {z : |z| < 1}. Such a function belongs to the class Gb defined by Silverman if the quotient of the analytic representations of convexity and starlikeness of the function maps the unit disk into a disk with center 1 and radius b. By using the Jack lemma we analyze the relation between the class Gb and the class S*[A,B] and its subclasses.
Smallest and greatest fixed points of quasimonotone increasing mappings
Authors: Uhl Roland
Published: January 2003

In a Banach space E (pre)ordered by a cone we consider a mapping f : [v,w] → E (v,w ∈ E, v ≤ w) which satisfies v ≤ f(v) and f(w) ≤ w. We show that f has a smallest and a greatest fixed point, if it is continuous, quasimonotone increasing and condensing, in essence. Finally we admit discontinuities with upward jumps.
Dual‐wavelength optical short‐pulse generation and wavelength switching using multiple‐optical‐paths
Authors: Wang D. N. , Zhang M. , Li H.
Published: January 2003

Dual‐wavelength optical picosecond pulses are generated simultaneously by using a multiple‐optical‐path self‐seeding scheme. The external cavity of the Fabry–Perot (F–P) laser diode consists of three fiber Bragg gratings (FBGs) and a variable optical delay line. The wavelengths of the optical short pulses can be selected conveniently by adjusting the FBG and switched simply by adjusting the optical delay line. A side mode suppression ratio of better than 18 dB is achieved by using a 1:99 optical coupler to enhance the seeding power. The system is simple, easy to operate, and low cost. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 233–235, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10730
A real‐time approach to array control based on a learned genetic algorithm
Authors: Caorsi Salvatore , Donelli Massimo , Lommi Andrea , Massa Andrea
Published: January 2003

In the framework of wireless communications, it is mandatory to guarantee the reliability of the receiver by assuring good quality at the end‐user, in order to successfully decode transmitted signals. To this end, a method for the design of adaptive antenna arrays is described in this paper. The proposed procedure, based on a customized genetic algorithm, allows real‐time control of the receiver's performance by acting on the discretized phase coefficients of the array elements. As a result, at the receiver, multiple and alternating interferences are considerably reduced with respect to the desired signal. In order to validate the proposed strategy, selected numerical results, concerning various environment conditions, are presented and deeply discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 235–238, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10731
Study on reduction in radiated emissions from PCB using test LSI
Authors: Haga Satoru , Nakano Ken , Sudo Toshio , Hashimoto Osamu
Published: January 2003

Radiation mechanism and reduction measures have been studied using test large scale integrated (LSI) circuits. The LSI operation mode that simultaneously drives external traces radiates the greatest amount of emissions. In this mode, an LSI‐mounted area has been found to behave as an opening from the electromagnetic viewpoint. Two approaches under consideration, ferrite on the LSI package and a copper sheet covering the LSI package, were verified to reduce emissions very effectively. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 238–242, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10732
Reflection ellipsometry for in‐situ determination of complex permittivity and thickness of a single‐layer material at several angles of incidence and frequencies
Authors: Sagnard F.
Published: January 2003

Several experimental results on common single‐layer samples have been obtained in the microwave domain using the reflection ellipsometry technique and two different data analysis procedures. They lead to estimations of complex permittivity as a function of the angle of incidence, frequency, and thickness. The influence of measurement uncertainties is discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 243–248, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10733
A stopband filter design using a 1D non‐periodic defected ground structure
Authors: Irigoyen Ieltxu A. Garde , del Río Bocio Carlos
Published: January 2003

The one‐dimensional (1D) defected ground structure (DGS) is used to control the cut‐off frequency characteristic. In this paper three non‐periodic filters are built, in order to show the versatility of DGS. Five unit cells of different shape with the same attenuation pole frequency were combined in each filter. The frequency response is essentially the same as in the case of periodic filters with equal square unit cells. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 249–250, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10734
Analysis of microstrip patch arrays using the FDTD method
Authors: Abd El‐Raouf Hany E. , Ma Lai‐Ching , Yu Wenhua , Mittra Raj
Published: January 2003

In this paper, microstrip patch arrays with both uniform phase and tapered distributions are analyzed via the finite‐difference time‐domain (FDTD) technique. The phase delay in the frequency domain is converted into a delay in the time domain when exciting the array. The far field pattern of the array is calculated from its aperture distribution, in a plane located just above the array. A PMC plane has been employed to reduce the problem to half its size by invoking the symmetry of the problem. The results are found to be in good agreement with those derived by using the method of moments (MoM). © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 250–254, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10735
Dual‐band printed diversity dipole antenna for WLAN access point
Authors: Lee Gwo‐Yun , Chen Hong‐Twu , Wong Kin‐Lu
Published: January 2003

A printed diversity dipole antenna suitable for applications in wireless local area network (WLAN) access points in the 2.4 GHz (2400–2484 MHz) and 5.2 GHz (5150–5350 MHz) bands is presented. The antenna comprises two stacked printed dipoles placed back‐to‐back. Each stacked dipole consists of two larger dipole arms for 2.4‐GHz band operation and two smaller dipole arms for 5.2‐GHz band operation. In addition, the proposed antenna can provide spatial diversity, because the obtained radiation patterns of the two stacked dipoles are directional in two complementary half spaces and the access point can thus switch between the two stacked dipoles for WLAN communication with maximum signal strength. Experimental results of a constructed prototype are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 254–257, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10736
Experimental results for a CW‐mode optically controlled microwave switch on a silicon‐based coplanar waveguide
Authors: Lee Sangil , Kuga Yasuo , Mullen Ruth Ann
Published: January 2003

A CW‐mode optically controlled microwave switch (CW‐mode OMS) on a coplanar waveguide (CPW) for both a standard and a new design with carrier‐confinement structure is investigated. We experimentally show that it may not be possible to obtain less than 7 dB of insertion loss with the standard OMS, and the carrier diffusion limits the improvement of insertion loss in CW‐mode operation. We present a new design with a carrier‐confinement structure with silicon (Si) substrate etching to confine the optically generated free‐carriers. Less than 2 dB of insertion loss is obtained with the new carrier‐confined OMS. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 257–262, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10737